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Sample records for montessori observer volume

  1. Distraction. The Montessori Observer. Volume 31, Number 2

    Science.gov (United States)

    International Montessori Society (NJ3), 2010

    2010-01-01

    "The Montessori Observer" is mailed four times each year, in March, May, September and November, to Society members throughout the world. The purpose is to provide news and information about the Society's work in Montessori education, and to extend awareness of Montessori principles throughout the world. This issue contains a feature…

  2. Nomenclature. The Montessori Observer. Volume 31, Number 3

    Science.gov (United States)

    International Montessori Society (NJ3), 2010

    2010-01-01

    "The Montessori Observer" is mailed four times each year, in March, May, September and November, to Society members throughout the world. The purpose is to provide news and information about the Society's work in Montessori education, and to extend awareness of Montessori principles throughout the world. This issue contains a feature article,…

  3. Clear Direction. The Montessori Observer. Volume 32, Number 2

    Science.gov (United States)

    International Montessori Society (NJ3), 2011

    2011-01-01

    "The Montessori Observer" is mailed four times each year, in March, May, September and November, to Society members throughout the world. The purpose is to provide news and information about the Society's work in Montessori education, and to extend awareness of Montessori principles throughout the world. This issue contains a feature…

  4. Perceptual Mistakes. The Montessori Observer. Volume 31, Number 4

    Science.gov (United States)

    International Montessori Society (NJ3), 2010

    2010-01-01

    "The Montessori Observer" is mailed four times each year, in March, May, September and November, to Society members throughout the world. The purpose is to provide news and information about the Society's work in Montessori education, and to extend awareness of Montessori principles throughout the world. This issue contains a feature…

  5. Personality Projections. The Montessori Observer. Volume 32, Number 1

    Science.gov (United States)

    International Montessori Society (NJ3), 2011

    2011-01-01

    "The Montessori Observer" is mailed four times each year, in March, May, September and November, to Society members throughout the world. The purpose is to provide news and information about the Society's work in Montessori education, and to extend awareness of Montessori principles throughout the world. This issue contains a feature…

  6. Power Struggles. The Montessori Observer. Volume 31, Number 1

    Science.gov (United States)

    International Montessori Society (NJ3), 2010

    2010-01-01

    "The Montessori Observer" is mailed four times each year, in March, May, September and November, to Society members throughout the world. The purpose is to provide news and information about the Society's work in Montessori education, and to extend awareness of Montessori principles throughout the world. This issue contains a feature…

  7. Scientific Education. The Montessori Observer. Volume 29, Number 4

    Science.gov (United States)

    International Montessori Society (NJ3), 2008

    2008-01-01

    "The Montessori Observer" is mailed four times each year, in March, May, September and November, to Society members throughout the world. The purpose is to provide news and information about the Society's work in Montessori education, and to extend awareness of Montessori principles throughout the world. This issue contains a feature article,…

  8. Context and Content. The Montessori Observer. Volume 30, Number 3

    Science.gov (United States)

    International Montessori Society (NJ3), 2009

    2009-01-01

    "The Montessori Observer" is mailed four times each year, in March, May, September and November, to Society members throughout the world. The purpose is to provide news and information about the Society's work in Montessori education, and to extend awareness of Montessori principles throughout the world. This issue contains a feature…

  9. Home-School Relations. The Montessori Observer. Volume 30, Number 1

    Science.gov (United States)

    International Montessori Society (NJ3), 2009

    2009-01-01

    "The Montessori Observer" is mailed four times each year, in March, May, September and November, to Society members throughout the world. The purpose is to provide news and information about the Society's work in Montessori education, and to extend awareness. This issue contains a feature article, "Home-School Relations," by…

  10. Montessori for All: Magnolia Montessori

    Science.gov (United States)

    EDUCAUSE, 2015

    2015-01-01

    The founders of Montessori For All, which opened Magnolia Montessori--a PK-8 public charter school in Austin, Texas--created a new school model that blends the best of authentic Montessori schooling (hands-on and self-directed learning) with best practices from high-performing charter schools (basic skills mastery to excel on standardized tests…

  11. Observation and Development: From Dr. Montessori's 1946 London Training Course

    Science.gov (United States)

    Montessori, Maria

    2016-01-01

    This article exhorts the observer to take notice of the unconscious and conscious levels of the young child's absorbent mind (infant stare). Montessori notes the social awareness of young children and suggests that their amazing awareness of people, not merely their activities, is integral to observation. [Reprinted with permission from "AMI…

  12. Proving Montessori: Identity and Dilemmas in a Montessori Teacher’s Lived Experience

    Directory of Open Access Journals (Sweden)

    Olivia Christensen

    2016-11-01

    Full Text Available This phenomenological case study was conducted to better understand the experience of a Montessori teacher in a leadership role. A veteran Montessori teacher, newly hired by an established Montessori preschool, was interviewed over the course of her first year in the position. A critical discourse analysis revealed multiple social identities that contributed to her desire, and ability, to be what she felt was an authentic Montessori educator. While some of these discourses and social identities aligned, some did not, creating ideational dilemmas that affected her work, relationships, and personal identity. The findings suggest that current Montessori discourse excludes important characteristics of the teacher-lived experience. Acknowledging and discussing the social challenges Montessori teachers face is a necessary addition to teacher preparation, teacher support systems, and Montessori leadership decisions.

  13. Best Practices in Montessori Secondary Programs

    Science.gov (United States)

    Donahoe, Marta

    2013-01-01

    This article is the result of years of study, both formal and informal; hundreds of hours of traditional and Montessori classroom observations; reading and digesting articles and books on secondary education, Montessori education, adolescent brain research, leadership, and best practices in education; and most enlightening of all, 20 years of…

  14. Preschool Children's Development in Classic Montessori, Supplemented Montessori, and Conventional Programs

    Science.gov (United States)

    Lillard, Angeline S.

    2012-01-01

    Research on the outcomes of Montessori education is scarce and results are inconsistent. One possible reason for the inconsistency is variations in Montessori implementation fidelity. To test whether outcomes vary according to implementation fidelity, we examined preschool children enrolled in high fidelity classic Montessori programs, lower…

  15. Characteristics of Montessori educators in Slovenia

    OpenAIRE

    Uštević, Maja

    2016-01-01

    This diploma thesis presents the Montessori pedagogy with a focus on the characteristics of Montessori educators and Montessori education in Slovenia. It presents the development of the Montessori pedagogy and life of Maria Montessori, related to education and institutions which operate on the principle of Montessori pedagogy worldwide and in Slovenia. It describes the role of the Montessori educator, his/her duties and responsibilities in the process of education according to the Montessori ...

  16. Montessori and Non-Montessori Early Childhood Teachers’ Attitudes Towards Inclusion and Access

    Directory of Open Access Journals (Sweden)

    Natalie Danner

    2015-11-01

    Full Text Available Montessori and non-Montessori general education early childhood teachers were surveyed about their attitudes towards including children with disabilities and providing access in their classrooms.  Both groups reported similar and positive supports for inclusion within their schools. Montessori teachers reported having less knowledge about inclusion and less special education professional development than their non-Montessori counterparts.   Implications for professional development and teacher preparation are described.

  17. Montessori Method and ICTs

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    Athanasios Drigas

    2016-03-01

    Full Text Available This article bridges the gap between the Montessori Method and Information and Communication Technologies (ICTs in contemporary education. It reviews recent research works which recall the Montessori philosophy, principles and didactical tools applying to today’s computers and supporting technologies in children’s learning process. This article reviews how important the stimulation of human senses in the learning process is, as well as the development of Montessori materials using the body and the hand in particular, all according to the Montessori Method along with recent researches over ICTs. Montessori Method within information society age acquires new perspectives, new functionality and new efficacy.

  18. Public Knowledge of Montessori Education

    Science.gov (United States)

    Murray, Angela

    2012-01-01

    The American public generally recognizes the name "Montessori" because so many schools across the country and around the world use the Montessori name. However, the Montessori community has long believed that misunderstandings abound. A recent dissertation study quantified Montessori awareness and identified misconceptions in particular for those…

  19. Značilnosti pedagogov montessori v Sloveniji

    OpenAIRE

    Uštević, Maja

    2016-01-01

    V diplomskem delu je predstavljena pedagogika montessori, s poudarkom na značilnostih pedagogov montessori in izobraževanjih montessori v Sloveniji. Predstavljen je razvoj pedagogike montessori in življenje Marie Montessori, povezano z vzgojo in izobraževanjem ter razvoj ustanov, ki delujejo po principu pedagogike montessori, po svetu in v Sloveniji. Opisana je vloga pedagoga montessori ter njegove obveznosti in dolžnosti v procesu vzgoje in izobraževanja po metodi pedagogike montessori. Pred...

  20. Montessori and Non-Montessori Early Childhood Teachers' Attitudes toward Inclusion and Access

    Science.gov (United States)

    Danner, Natalie; Fowler, Susan A.

    2015-01-01

    Montessori and non-Montessori general education early childhood teachers were surveyed about their attitudes toward including children with disabilities and providing these students access to the curriculum. Both groups reported similar and positive system-wide supports for inclusion within their schools. Montessori teachers reported having less…

  1. Providing Montessori: Identity and Dilemmas in a Montessori Teacher's Lived Experience

    Science.gov (United States)

    Christensen, Olivia

    2016-01-01

    This phenomenological case study was conducted to better understand the experience of a Montessori teacher in a leadership role. A veteran Montessori teacher, newly hired by an established Montessori preschool, was interviewed over the course of her first year in the position. A critical discourse analysis revealed multiple social identities that…

  2. Montessori Grows in Tanzania

    Science.gov (United States)

    Hoke, Betsy

    2014-01-01

    Imagine going back in time and being the guiding spirit in Montessori's first "Casa dei Bambini" but with all the knowledge and skills developed as a Montessori teacher today. That is precisely the privilege this author has had as, over the past 2 years, she has worked to establish an Early Childhood Montessori program in Usa River,…

  3. Views on Montessori Approach by Teachers Serving at Schools Applying the Montessori Approach

    Science.gov (United States)

    Atli, Sibel; Korkmaz, A. Merve; Tastepe, Taskin; Koksal Akyol, Aysel

    2016-01-01

    Problem Statement: Further studies on Montessori teachers are required on the grounds that the Montessori approach, which, having been applied throughout the world, holds an important place in the alternative education field. Yet it is novel for Turkey, and there are only a limited number of studies on Montessori teachers in Turkey. Purpose of…

  4. Authentic Montessori: The Teacher Makes the Difference

    Science.gov (United States)

    Huxel, Alexa C.

    2013-01-01

    What are the elements that make up authentic Montessori? Is Montessori something concrete or abstract? Are there intangibles that make Montessori what it is? Many classrooms today have Montessori materials and small tables and chairs. Are they authentic Montessori? When examining areas that traditionally make defining authentic Montessori…

  5. Science and culture around the Montessori's first "Children's Houses" in Rome (1907-1915).

    Science.gov (United States)

    Foschi, Renato

    2008-01-01

    Between 1907 and 1908, Maria Montessori's (1870-1952) educational method was elaborated at the Children's Houses of the San Lorenzo district in Rome. This pioneering experience was the basis for the international fame that came to Montessori after the publication of her 1909 volume dedicated to her "Method." The "Montessori Method" was considered by some to be scientific, liberal, and revolutionary. The present article focuses upon the complex contexts of the method's elaboration. It shows how the Children's Houses developed in relation to a particular scientific and cultural eclecticism. It describes the factors that both favored and hindered the method's elaboration, by paying attention to the complex network of social, institutional, and scientific relationships revolving around the figure of Maria Montessori. A number of "contradictory" dimensions of Montessori's experience are also examined with a view to helping to revise her myth and offering the image of a scholar who was a real early-twentieth-century prototype of a "multiple" behavioral scientist. Copyright 2008 Wiley Periodicals, Inc.

  6. The Kodaikanal Experience: Chapter II. Kahn-Montessori Interview

    Science.gov (United States)

    NAMTA Journal, 2013

    2013-01-01

    This article provides an interview transcript between David Kahn and Mario Montessori (1898-1982), son of Dr. Maria Montessori. Mario Montessori dedicated his life to the preservation, dissemination and application of Montessori's works. Herein Kahn asks Montessori about his time living in the hills of Kodaikanal, India. Montessori touches upon…

  7. Playful Learning and Montessori Education

    Science.gov (United States)

    Lillard, Angeline S.

    2013-01-01

    Although Montessori education is often considered a form of playful learning, Maria Montessori herself spoke negatively about a major component of playful learning--pretend play, or fantasy--for young children. In this essay, the author discusses this apparent contradiction: how and why Montessori education includes elements of playful learning…

  8. Montessori and Music.

    Science.gov (United States)

    Barnett, Elise Braun

    1999-01-01

    Discusses principles of Montessori music education, examining the fundamental characteristics of childhood and the role that music plays in development. Explores the inner satisfaction that comes from experiencing movement with music through compositions and folk music. Emphasizes the Montessori practices of meeting sensorimotor needs of children…

  9. Montessori All Day, All Year

    Science.gov (United States)

    Black, Connie; Davis, Liza

    2015-01-01

    Introducing real community into the Children's House goes back to the roots of Montessori education through all-day Montessori. The all-day environment is a house where children live with a "developmental room" of Montessori materials including a living room, kitchen, dining area, bedroom, bathroom, greeting rooms, and outdoor spaces.…

  10. Montessori Transformation at Computer Associates.

    Science.gov (United States)

    Mars, Lisa

    2002-01-01

    Describes the growth of the all-day Montessori program for children ages 6 weeks to 6 years at Computer Associates' corporate headquarters and multiple sites worldwide. Focuses on placement of AMI Montessori-trained teachers, refurbishing of the child development centers to fit Montessori specifications, and the Nido--the children's community--and…

  11. Origins of Montessori Programming for Dementia.

    Science.gov (United States)

    Camp, Cameron J

    2010-01-01

    The focus of this article is on the evolution of the use of Montessori educational methods as the basis for creating interventions for persons with dementia. The account of this evolution is autobiographical, as the development of Montessori Programming for Dementia (MPD) initially was through the efforts of myself and my research associates. My initial exposure to Maria Montessori's work came as a result of my involvement with my own children's education. This exposure influenced ongoing research on development of cognitive interventions for persons with dementia. A brief description of Montessori's work with children and the educational methods she developed is followed by a description of how this approach can be translated into development of activities for persons with dementia. Assessment tools to document effects of MPD were created, focusing on observational tools to measure engagement and affect during individual and group activities programming for persons with dementia. Examples of the use of MPD by researchers, staff members, and family members are given, as well as examples of how persons with dementia can provide MPD to other persons with dementia or to children. Finally, examples of MPD's dissemination internationally and future directions for research are presented.

  12. The Montessori Method

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    Cathleen HASKINS

    2010-12-01

    Full Text Available Dr. Maria Montessori provided the world with a powerful philosophy and practice for the advancement of humanity: change how we educate children and we change the world. She understood two things very clearly: One, that we can build a better world, a more just and peaceful place, when we educate for the realization of the individual and collective human potential; and two, that the only way to create an educational system that will that will serve this end is to scrap the current system entirely and replace it with a completely new system. She gave us a system through which to accomplish that goal: The Montessori Method. The following is a personal and professional account of the Montessori Method of educating children.

  13. Montessori Parenting: An Idea Whose Time Has Come

    Science.gov (United States)

    McFarland, Sonnie; McFarland, Jim

    2013-01-01

    Since Dr. Maria Montessori's discovery of the true nature of childhood over a century ago, children around the globe have benefited from Montessori education. However, even parents who have children enrolled in Montessori schools could derive further benefits through the implementation of Montessori principles and practices in the home. Helping…

  14. The effects of Montessori education: evidence from admission lotteries

    NARCIS (Netherlands)

    Ruijs, N.

    2014-01-01

    Little is known about the effects of Montessori education, even though many students in many countries are educated in Montessori classrooms. This study investigates the causal effects of Montessori secondary education by exploiting admission lotteries in Dutch Montessori schools. The results

  15. The effects of Montessori education: Evidence from admission lotteries

    NARCIS (Netherlands)

    Ruijs, N.

    2017-01-01

    This study investigates the causal effects of Montessori secondary education by exploiting admission lotteries in Dutch Montessori schools. Results from 308 to 625 students indicate that Montessori education provides an alternative way to attain similar outcomes. Montessori students obtain their

  16. Montessori education: a review of the evidence base

    Science.gov (United States)

    Marshall, Chloë

    2017-10-01

    The Montessori educational method has existed for over 100 years, but evaluations of its effectiveness are scarce. This review paper has three aims, namely to (1) identify some key elements of the method, (2) review existing evaluations of Montessori education, and (3) review studies that do not explicitly evaluate Montessori education but which evaluate the key elements identified in (1). The goal of the paper is therefore to provide a review of the evidence base for Montessori education, with the dual aspirations of stimulating future research and helping teachers to better understand whether and why Montessori education might be effective.

  17. Work in Society and in Montessori Classrooms

    Science.gov (United States)

    Chattin-McNichols, John

    2013-01-01

    Montessori educators follow Montessori's lead and use the word "work" to describe the child's concentrated attention with a hands-on material. But this word may lead to communication problems with parents and those in the non-Montessori world: educators, administrators, accreditors, and so on. These communication problems are…

  18. Removing Supplementary Materials from Montessori Classrooms Changed Child Outcomes

    Science.gov (United States)

    Lillard, Angeline S.; Heise, Megan J.

    2016-01-01

    Montessori classrooms vary in the degree to which they adhere to Maria Montessori's model, including in the provision of materials. Specifically, some classrooms use only Montessori materials, whereas others supplement the Montessori materials with commercially available materials like puzzles and games. A prior study suggested such…

  19. Racial and Economic Diversity in U.S. Public Montessori Schools

    Directory of Open Access Journals (Sweden)

    Mira Catherine Debs

    2016-11-01

    Full Text Available As public Montessori schools rapidly expand through the United States, the question then arises: What population of students do the schools serve? This study presents a new empirical data set examining the racial and economic diversity of 300 whole-school, public Montessori programs open in 2012–2013, where the entire school uses the Montessori Method. While school-choice scholars are concerned that choice programs like Montessori lead to greater student segregation by race and social class, this study finds a variety of outcomes for public Montessori. Public Montessori as a sector has strengths in student racial and socioeconomic diversity, but it also has diversity challenges, particularly among Montessori charters. The study concludes with recommended strategies for public Montessori schools to enroll a racially and economically diverse student body.

  20. The Impact of Montessori Practices

    Science.gov (United States)

    Mushamba, Ashley; Burney, Sonya Franklin; Kent, Jacqueline

    2017-01-01

    This mixed methods study examined the impact of School Y's Montessori approach on their students' academic achievement, perceptions of executive functioning skills, and the school's culture. The purpose of this study was to determine the impact of length of enrollment on academic achievement in a Montessori upper elementary and middle school…

  1. Pedagogika a škola Marie Montessori v České republice

    OpenAIRE

    Glaserová, Barbora

    2012-01-01

    This thesis "Pedagogy and Maria Montessori School in the Czech Republic" in the theoretical part describes the life of Maria Montessori, Montessori principles of education and development of Montessori schools with a focus on their development in the Czech Republic. The practical part deals with a case study of a Prague school with Montessori principles and a questionnaire survey with the headmaster of Montessori schools.

  2. The Scientist in the Classroom: The Montessori Teacher as Scientist

    Science.gov (United States)

    Sackett, Ginni

    2016-01-01

    Ginni Sackett shares insights ignited by a presentation given by Professori Raniero Regni in Rome at an AMI International Trainers Meeting. Dr. Regni stated that, "To go beyond Montessori is to rediscover Montessori. Montessori is waiting for us in the future." By re-examining Montessori's writings, Sackett traces the subtle ways in…

  3. Montessori, Maslow, and Self-Actualization

    Science.gov (United States)

    Weinberg, David R.

    2011-01-01

    What must never be forgotten by the Montessori teacher, or by any teacher of young children, is that his or her "primary" task, his or her "primary" obligation, his or her "primary" sacred duty is not the teaching of the "three Rs" but that of nurturing the psychological health of the child. Every element of Montessori methodology is designed for…

  4. MATERIALS AND (LANGUAGE LEARNING ENVIRONMENT BASED ON MONTESSORI CONCEPTS

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    Christina Kristiyani

    2018-04-01

    Full Text Available Montessori Education is widely spread in almost all countries in the world. Even though this school is meant for all kinds of learners including “normal” learners, the Montessori education concepts used in Montessori schools will be very supportive education for children with special needs. Therefore, the schools which adopt Montessori education concepts can facilitate inclusion, especially with the concepts of ‘I can do it myself.’ Inclusive education needs to be carefully prepared and implemented by schools. The movement brings about some challenges for teachers. This paper explores the environment and materials based on Montessori education concepts. The environment and materials are suitable for all types of learners and thus can be an option to be implemented in the inclusive education setting. Teaching materials rooted in Montessori education concepts indeed cater all ages and embrace the needs of all students.

  5. The Value of Regional Montessori Organizations

    Science.gov (United States)

    Cichucki, Penny HildeBrandt

    2006-01-01

    In this article, the author explains how administrators who have feelings about isolation and disconnection from other Montessori schools may find support and networking through a variety of ways. Administrators may connect with others through the AMS (American Montessori Society) Heads of Schools ListServer, a forum for discussion of topics…

  6. Perpaduan Konsep Islam dengan Metode Montessori dalam Membangun Karakter Anak

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    Aprilian Ria Adisti

    2016-09-01

    Full Text Available Studi ini menguraikan perpaduan antara konsep Islam dan metode Montessori terutama untuk membangun karakter yang baik bagi anak-anak. Metode pendidikan Montessori adalah salah satu metode yang populer sebagai salah satu metode terbaik di Barat, terutama untuk mengajar anak-anak. Dalam al-Quran, sebagai sumber kehidupan masyarakat muslim, telah disebutkan semua laporan Montessori. Ada lima konsep dalam metode pendidikan Montessori yang bisa dipadukan dengan teori mengajar anak-anak dalam al-Quran dan al-Hadits; Konsep Kebebasan dengan konsep "Fitrah", Struktur dengan konsep Langkah demi langkah, Realitas dan Alam dengan konsep Mencintai Alam dan Makhluk Hidup, Keindahan dan Nuansa sejalan dengan konsep Kebersihan dan Keindahan Islam, dan Materi Montessori dengan Proses Konsep Pembelajaran Hidup. Hasil perpaduan nilai-nilai tersebut dapat membangun karakter yang baik untuk anak-anak, terutama menjadikan mereka orang beragama dengan sikap yang baik untuk masa depan mereka.   This study simply reveals about the assimilation of Islamic education values and Montessori education method especially to build the good character for children. Montessori education method is one of the method which really popular as one of the best method in Western, especially for teaching children. In al-Quran, as the source of Moslem people’s life, has mentioned all the statements of Montessori. There are five aspects in Montessori education methods that we collaborate with the theory of teaching children in al-Quran and al-Hadits; Concept of Freedom with Concept of “Fitrah”, Structure and Order with Concept of Step by Step, Reality and Nature with Concept of Loving the Nature and Living Being, Beauty and Nuance in line with Concept of Cleanness and Beauty of Islam, and Montessori Materials with Concept Process of Life Learning. The result of collaboration those methods can build the good character for children, especially create them to be religious person with the

  7. Montessori Preschool Elevates and Equalizes Child Outcomes: A Longitudinal Study.

    Science.gov (United States)

    Lillard, Angeline S; Heise, Megan J; Richey, Eve M; Tong, Xin; Hart, Alyssa; Bray, Paige M

    2017-01-01

    Quality preschool programs that develop the whole child through age-appropriate socioemotional and cognitive skill-building hold promise for significantly improving child outcomes. However, preschool programs tend to either be teacher-led and didactic, or else to lack academic content. One preschool model that involves both child-directed, freely chosen activity and academic content is Montessori. Here we report a longitudinal study that took advantage of randomized lottery-based admission to two public Montessori magnet schools in a high-poverty American city. The final sample included 141 children, 70 in Montessori and 71 in other schools, most of whom were tested 4 times over 3 years, from the first semester to the end of preschool (ages 3-6), on a variety of cognitive and socio-emotional measures. Montessori preschool elevated children's outcomes in several ways. Although not different at the first test point, over time the Montessori children fared better on measures of academic achievement, social understanding, and mastery orientation, and they also reported relatively more liking of scholastic tasks. They also scored higher on executive function when they were 4. In addition to elevating overall performance on these measures, Montessori preschool also equalized outcomes among subgroups that typically have unequal outcomes. First, the difference in academic achievement between lower income Montessori and higher income conventionally schooled children was smaller at each time point, and was not (statistically speaking) significantly different at the end of the study. Second, defying the typical finding that executive function predicts academic achievement, in Montessori classrooms children with lower executive function scored as well on academic achievement as those with higher executive function. This suggests that Montessori preschool has potential to elevate and equalize important outcomes, and a larger study of public Montessori preschools is warranted.

  8. Montessori Preschool Elevates and Equalizes Child Outcomes: A Longitudinal Study

    Directory of Open Access Journals (Sweden)

    Angeline S. Lillard

    2017-10-01

    Full Text Available Quality preschool programs that develop the whole child through age-appropriate socioemotional and cognitive skill-building hold promise for significantly improving child outcomes. However, preschool programs tend to either be teacher-led and didactic, or else to lack academic content. One preschool model that involves both child-directed, freely chosen activity and academic content is Montessori. Here we report a longitudinal study that took advantage of randomized lottery-based admission to two public Montessori magnet schools in a high-poverty American city. The final sample included 141 children, 70 in Montessori and 71 in other schools, most of whom were tested 4 times over 3 years, from the first semester to the end of preschool (ages 3–6, on a variety of cognitive and socio-emotional measures. Montessori preschool elevated children’s outcomes in several ways. Although not different at the first test point, over time the Montessori children fared better on measures of academic achievement, social understanding, and mastery orientation, and they also reported relatively more liking of scholastic tasks. They also scored higher on executive function when they were 4. In addition to elevating overall performance on these measures, Montessori preschool also equalized outcomes among subgroups that typically have unequal outcomes. First, the difference in academic achievement between lower income Montessori and higher income conventionally schooled children was smaller at each time point, and was not (statistically speaking significantly different at the end of the study. Second, defying the typical finding that executive function predicts academic achievement, in Montessori classrooms children with lower executive function scored as well on academic achievement as those with higher executive function. This suggests that Montessori preschool has potential to elevate and equalize important outcomes, and a larger study of public Montessori

  9. Montessori-based dementia care.

    Science.gov (United States)

    Cline, Janet

    2006-10-01

    Montessori-based Dementia Care is an approach used in Alzheimer's care that does not involve chemical or physical restraints. This program works by giving the elder with Alzheimer/Dementia a purpose by getting them involved. When staff/families care for a confused Alzheimer/Dementia patient, who is having behaviors, the Montessori program teaches them to look at what is causing the behavior. When assessing the elder to determine what is causing the behavior, the goal is to find the answer, but the answer cannot be dementia. The goal of the program is to bring meaning to the life of an Alzheimer/Dementia elder.

  10. Montessori-based activities for long-term care residents with advanced dementia: effects on engagement and affect.

    Science.gov (United States)

    Orsulic-Jeras, S; Judge, K S; Camp, C J

    2000-02-01

    Sixteen residents in long-term care with advanced dementia (14 women; average age = 88) showed significantly more constructive engagement (defined as motor or verbal behaviors in response to an activity), less passive engagement (defined as passively observing an activity), and more pleasure while participating in Montessori-based programming than in regularly scheduled activities programming. Principles of Montessori-based programming, along with examples of such programming, are presented. Implications of the study and methods for expanding the use of Montessori-based dementia programming are discussed.

  11. Montessori Practices: Options for a Digital Age

    Science.gov (United States)

    Powell, Mark

    2016-01-01

    Mark Powell's plea for an open-minded view on the full scope of technology that is compatible with Montessori education enriches Maria Montessori's clear modernism of welcoming science into her educational vision. Growing up digital can be intelligently managed so that "technology may offer an effective, adaptable, and easily available means…

  12. Determining the Measurement Quality of a Montessori High School Teacher Evaluation Survey

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    Anthony Philip Setari

    2017-05-01

    Full Text Available The purpose of this study was to conduct a psychometric validation of a course evaluation instrument, known as a student evaluation of teaching (SET, implemented in a Montessori high school. The authors demonstrate to the Montessori community how to rigorously examine the measurement and assessment quality of instruments used within Montessori schools. The Montessori high school community needs an SET that has been rigorously examined for measurement issues. The examined SET was developed by a Montessori high school, and the sample data were collected from Montessori high school students. Using a Rasch partial credit model, the results of the analysis identified several measurement issues, including multidimensionality, misfit items, and inappropriate item difficulty levels. A revised version of the SET underwent the same analysis procedure, and the results indicated that measurement issues persisted. The authors suggest several ways to improve the overall measurement quality of the instrument while keeping the Montessori foundation. Additional validation studies with a revised version of the SET will be needed before the instrument can be endorsed for full implementation in a Montessori setting.

  13. A Systematic Review of Montessori-Based Activities for Persons With Dementia.

    Science.gov (United States)

    Sheppard, Christine L; McArthur, Caitlin; Hitzig, Sander L

    2016-02-01

    Montessori-based activities are becoming a popular approach for the care of older adults living with dementia. The aim of this study was to systematically assess the quality of the research examining the benefits of Montessori-based activities for persons with dementia. Six peer-reviewed databases were systematically searched for all relevant articles published until April 2015. Included articles were peer-reviewed studies published in English that employed Montessori-based activities with persons with dementia. Methodological quality was assessed by 2 independent raters using the Physiotherapy Evidence Database Scale or the Downs and Black evaluation tool. Levels of evidence were assigned to the study design using a modified Sackett scale. One hundred fifty articles were identified, and 14 were selected for inclusion. Level-2 evidence examining the impact of Montessori-based activities on eating behaviors suggested that difficulties with eating could be reduced with Montessori training. There was limited level-4 evidence for the benefits of Montessori-based activities on cognition, wherein benefits appeared to be specific to lower-level cognitive abilities including memory and attention. Finally, there is level-1 (n = 1), level-2 (n = 3), and level-4 (n = 6) evidence for the benefits of Montessori-based activities on engagement and affect, whereby constructive engagement and positive affect were heightened. Overall, there is a strong level of evidence for the benefits of Montessori-based activities on eating behaviors and weak evidence for the benefits on cognition. Evidence for the benefits of Montessori-based activities on engagement and affect are mixed. Future research is needed to examine the long-term benefits of Montessori-based activities. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  14. Understanding Optimal School Experience: Contributions from Montessori Education

    Science.gov (United States)

    Rathunde, Kevin

    2014-01-01

    After summarizing the results from two studies the author conducted in Montessori middle schools, the chapter discusses nine characteristics of Montessori education in relation to various theoretical perspectives on education and development. [This article originally appeared as NSSE Yearbook Vol. 113, No. 1.

  15. Prednosti metode Montessori pri obravnavi oseb z demenco

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    Andreja Ljubič

    2017-03-01

    Full Text Available Uvod: Demenca je kronično obolenje s tendenco upadanja kognitivnih sposobnosti obolelega. Uporaba metod za obvladovanje in trening osnovnih življenjskih aktivnosti, ki omogočajo daljše obdobje samostojnega življenja pacienta z demenco, je v tujini uveljavljena z različnimi novejšimi koomplementarnimi pristopi. Ena izmed uveljavljenih metod je pristop Marie Montessori, prilagojen odraslim pacientom z demenco. V članku je predstavljena metoda montessori pri obravnavi pacienta z demenco in njeni učinki na kakovost življenja pacienta z demenco. Metode: Uporabljena je bila deskriptivna raziskovalna metodologija s pregledom domače in tuje literature. Za prikaz pregleda petih preko spleta dostopnih podatkovnih baz in odločanja o uporabnosti pregledanih virov je bila uporabljena metoda PRISMA. V končni pregled literature je bilo ključenih 19 člankov, objavljenih do maja 2016. Za obdelavo podatkov je bil uporabljen model analize konceptov. Večina zajetih raziskav je bila izvedena v Združenih državah Amerike. Rezultati: Po pregledu raziskav so bila identificirana tri tematska področja: (1 vpliv metode montessori na sodelovanje in prizadevanje, (2 vpliv metode montessori na vedenje, povezano s hranjenjem, in (3 vpliv metode montessori na širšo skupino kognitivnih sposobnosti. Diskusija in zaključek: Kljub majhnemu številu člankov, ki opisujejo uporabo metode montessori pri obravnavi pacientov z demenco, metodo lahko predstavimo kot učinkovito. Avtorji raziskav ugotavljajo, da pristop ne le omogoča ohranjanje kognitivnih sposobnosti, temveč le-te celo izboljšuje.

  16. Physical Activity in Preschool Children: Comparison between Montessori and Traditional Preschools

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    Pate, Russell R.; O'Neill, Jennifer R.; Byun, Wonwoo; McIver, Kerry L.; Dowda, Marsha; Brown, William H.

    2014-01-01

    Background: Little is known about the influence of Montessori methods on children's physical activity (PA). This cross-sectional study compared PA of children attending Montessori and traditional preschools. Methods: We enrolled 301 children in 9 Montessori and 8 traditional preschools in Columbia, South Carolina. PA was measured by accelerometry…

  17. Creating an Amazing Montessori Toddler Home Environment

    Science.gov (United States)

    Woo, Stephanie

    2014-01-01

    The author states that raising her twins the Montessori way has made her life easy. Imagine two 1-year-olds eating entire meals on their own, setting their own tables by 20 months, and becoming potty-trained before 2. These are not statistics found in just one household. Children raised the Montessori way can take care of themselves and their…

  18. Maria Montessori, John Dewey, and William H. Kilpatrick

    Science.gov (United States)

    Thayer-Bacon, Barbara

    2012-01-01

    I explore Montessori's story in terms of her initial warm reception by America to her educational research, and her later cooling off, once Dewey's student, Kilpatrick, published The Montessori System Examined and declared her work to be based on psychological theory that was fifty years behind the times. I argue that there is a troubling gendered…

  19. Using the Montessori approach for a clientele with cognitive impairments: a quasi-experimental study design.

    Science.gov (United States)

    Giroux, Dominique; Robichaud, Line; Paradis, Martin

    2010-01-01

    The choice of activities responding to the needs of people with moderate to severe dementia is a growing concern for care providers trying to target the need for a feeling of self-accomplishment by adapting activities to the abilities of elderly patients. The activities created by Maria Montessori seem to be adaptable to this clientele. This study evaluates the short-term effects, as compared to regular activities offered in the milieu. This is a quasi-experimental study where each of the 14 participants was observed and filmed in two conditions: during Montessori activities, during regular activities, and one control condition (no activity). The results show that Montessori activities have a significant effect on affect and on participation in the activity. They support the hypothesis that when activities correspond to the needs and abilities of a person with dementia, these positive effects are also observed on behaviours. This study enabled its authors to corroborate the findings presented in the literature and to contribute additional elements on the positive effects of the use of Montessori activities and philosophy. Used with people with moderate to severe dementia these allow the satisfaction of their basic psychological needs, their well being, and hence, on their quality of life.

  20. Students of Color and Public Montessori Schools: A Review of the Literature

    Science.gov (United States)

    Debs, Mira C.; Brown, Katie E.

    2017-01-01

    Students of color comprise a majority in public Montessori school enrollments around the United States, and practitioners are often asked for evidence of the Montessori Method's benefits for these students. This article examines the relevant literature related to the experiences of students of color in public Montessori schools. Research finds…

  1. The Social Relevance of Montessori in the First Plane

    Science.gov (United States)

    Andrews, Sarah Werner

    2015-01-01

    This article represents an amazing reversal of linguistic analysis. Usually Montessori language is translated into "state" terminology. In this case, Sarah Werner Andrews puts state quality assessment terms into Montessori language. For example, domains for school readiness include 1) physical wellbeing and motor development, 2) social…

  2. International Education: The International Baccalaureate, Montessori and Global Citizenship

    Science.gov (United States)

    Brunold-Conesa, Cynthia

    2010-01-01

    The International Baccalaureate (IB) programs and Montessori education both claim to promote values associated with global citizenship in order to help prepare students for new challenges presented by an increasingly globalized world. While the IB's secondary programs are widespread in international schools, Montessori programs at that level are…

  3. [Montessori method applied to dementia - literature review].

    Science.gov (United States)

    Brandão, Daniela Filipa Soares; Martín, José Ignacio

    2012-06-01

    The Montessori method was initially applied to children, but now it has also been applied to people with dementia. The purpose of this study is to systematically review the research on the effectiveness of this method using Medical Literature Analysis and Retrieval System Online (Medline) with the keywords dementia and Montessori method. We selected lo studies, in which there were significant improvements in participation and constructive engagement, and reduction of negative affects and passive engagement. Nevertheless, systematic reviews about this non-pharmacological intervention in dementia rate this method as weak in terms of effectiveness. This apparent discrepancy can be explained because the Montessori method may have, in fact, a small influence on dimensions such as behavioral problems, or because there is no research about this method with high levels of control, such as the presence of several control groups or a double-blind study.

  4. Il periodo indiano di Maria Montessori

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    Giacomo Cives

    2011-11-01

    Full Text Available On Maria Montessori (1870-1952, Italian educator of the twentieth century the most successful in the world, there is, also a growing if belated, interest in more recent times also in Italy. So to confine ourselves to two thousand years, studies have appeared on his life and works of great interest, finally showing that its value is recognized beyond resistance of the idealistic and Catholic area survived for a long time. The author investigates these new frontiers of research on the Montessori starting from a new biography dedicated to her which gives attention also to the Indian period.

  5. Further Fostering Intrinsic Motivation in the Montessori Elementary Classroom

    Science.gov (United States)

    Fitch, Victoria A.

    2013-01-01

    The Montessori classroom appears to be the ideal learning environment for children throughout elementary and middle school. It is based on the philosophy of Dr. Maria Montessori which describes an environment tailored to the Sensitive Periods of children, prepared with materials appropriate for the age and abilities of the children in a particular…

  6. Students of Color and Public Montessori Schools: A Review of the Literature

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    Mira Debs

    2017-05-01

    Full Text Available Students of color comprise a majority in public Montessori school enrollments around the United States, and practitioners are often asked for evidence of the Montessori Method’s benefits for these students. This article examines the relevant literature related to the experiences of students of color in public Montessori schools. Research finds Montessori education offers both opportunities and limitations for students of color in attending diverse schools, developing executive functions, achieving academically, accessing early childhood education and culturally responsive education, minimizing racially disproportionate discipline, and limiting overidentification for special education. Public Montessori education’s efficacy with students of color may be limited by several factors: the lack of diversity of the teaching staff and culturally responsive teacher education, schools that struggle to maintain racially diverse enrollments, and the challenge of communicating Montessori’s benefits to families with alternative views of education. The review concludes with directions for future research.

  7. Objectively measured sedentary behavior in preschool children: comparison between Montessori and traditional preschools.

    Science.gov (United States)

    Byun, Wonwoo; Blair, Steven N; Pate, Russell R

    2013-01-03

    This study aimed to compare the levels of objectively-measured sedentary behavior in children attending Montessori preschools with those attending traditional preschools. The participants in this study were preschool children aged 4 years old who were enrolled in Montessori and traditional preschools. The preschool children wore ActiGraph accelerometers. Accelerometers were initialized using 15-second intervals and sedentary behavior was defined as Montessori preschools, after adjusting for selected potential correlates of preschoolers' sedentary behavior. Children attending Montessori preschools spent less time in sedentary behavior than those attending traditional preschools during the in-school (44.4. min/hr vs. 47.1 min/hr, P = 0.03), after-school (42.8. min/hr vs. 44.7 min/hr, P = 0.04), and total-day (43.7 min/hr vs. 45.5 min/hr, P = 0. 009) periods. School type (Montessori or traditional), preschool setting (private or public), socio-demographic factors (age, gender, and socioeconomic status) were found to be significant predictors of preschoolers' sedentary behavior. Levels of objectively-measured sedentary behavior were significantly lower among children attending Montessori preschools compared to children attending traditional preschools. Future research should examine the specific characteristics of Montessori preschools that predict the lower levels of sedentary behavior among children attending these preschools compared to children attending traditional preschools.

  8. Leaving a Legacy: Passing Montessori to the Next Generation

    Science.gov (United States)

    Loveless, Sylvia

    2012-01-01

    For each of the past 19 years, the American Montessori Society has chosen to recognize one Montessorian as an AMS Living Legacy. Recipients are honored at the AMS annual conference for their salient work or volunteerism in the Montessori field and their dedication and leadership that has made an impact on the AMS community. It seems fitting that…

  9. Método de Montessori aplicado à demência: revisão da literatura Método Montessori aplicado a la demencia: revisión de la literatura Montessori Method applied to dementia: literature review

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    Daniela Filipa Soares Brandão

    2012-06-01

    Full Text Available O método de Montessori foi aplicado inicialmente às crianças, mas atualmente aplica-se a pessoas com demência. O objetivo deste trabalho é fazer uma revisão sistemática da investigação sobre a eficácia desse método, utilizando a Medical Literature Analysis and Retrieval System Online (Medline com as palavras-chave demência e método de Montessori. Foram selecionados 10 estudos, onde se verificam melhorias significativas na participação e no envolvimento construtivo e diminuição dos afectos negativos e do envolvimento passivo. Não obstante, as revisões da literatura acerca desta intervenção não farmacológica em demência classificam esse método como fraco, em termos de eficácia. Essa aparente discrepância pode explicar-se porque o método de Montessori pode ter, de fato, uma influência pouco significativa em dimensões como a dos problemas comportamentais ou porque não existe investigação acerca desse método com elevados níveis de controle como são a presença de vários grupos de controle ou o duplo-cego.El método Montessori se aplicó inicialmente a los niños, pero ahora se aplica a las personas con demencia. El propósito de este estudio es revisar de forma sistemática la investigación sobre la eficacia de este método, utilizando Medical Literature Analysis and Retrieval System Online (Medline con las palabras clave demencia y método Montessori. Se seleccionaron 10 estudios, que tienen mejoras significativas en la participación y en el compromiso constructivo, y la reducción de efectos negativos y de la participación pasiva. Sin embargo, la revisión de la literatura sobre esta intervención no farmacológica en la demencia clasifica este método como débil en términos de eficacia. Esta aparente discrepancia puede explicarse porque el método Montessori puede tener una influencia poco significativa en los problemas de conducta, o porque no hay investigación sobre este método con altos niveles de

  10. The Power of Montessori's Positive Psychology in an Expanding Universe.

    Science.gov (United States)

    Haines, Annette

    1999-01-01

    Relates Montessori theory of development with the concept of connection to the universe and natural world, noting Montessori education's role in nurturing reestablished connection with the natural world. Describes events leading to a fulfilled life as part of psychological normalization, noting the importance of identifying positive tendencies of…

  11. Principle Elements of Curriculum in the Preschool Pattern of Montessori

    Science.gov (United States)

    Bahmaee, Azizollah Baboli; Saadatmand, Zohreh; Yarmohammadian, Mohammad Hossein

    2016-01-01

    Montessori the physician and educational philosopher was probably one of the most prominent and famous education theorizer in the field of preschool education. Current research attempts to extract and clarify the major elements of curriculum by reliance on Montessori viewpoints. In this paper first the philosophical basics of preschool education…

  12. The effect of Montessori Method on teaching cultural and creative ...

    African Journals Online (AJOL)

    The Effect of the Montessori Method on teaching was investigated among children to discover their artistic development in Zaria, Kaduna State. The problem of the study is that the Montessori Method on teaching cultural and creative arts is not adequately explored in the primary schools, while other teaching methods used, ...

  13. La Società Umanitaria e la diffusione del Metodo Montessori (1908-1923

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    Irene Pozzi

    2015-07-01

    Full Text Available The Società Umanitaria ofMilan, between 1918 and 1923, played an essential role in spreading and developing the Montessori Method. Studying in the Historical Archive of Società Umanitaria the numerous documents there collected, the author reconstructed the crucial moments of the extremely significant collaboration between Maria Montessori and Augusto Osimo, General Secretary of the Società Umanitaria.This complex and in-depth investigation was guided by the analysis, in specific, of the training courses for Montessori teachers organised by Società Umanitaria, essentially unexamined before this study, that allowed the researcher to have a deep insight into the action of Società Umanitaria aimed to promote and implement the Montessori Method in Italy and all around the world.

  14. The Application of Montessori Method in Learning Mathematics: An Experimental Research

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    Faryadi, Qais

    2017-01-01

    The prime objective of this research was to investigate whether the Montessori method of learning helped kindergarten pupils improve their mathematical proficiency, critical thinking and problem-solving skills, besides training them to be responsible learners. Quantitative, qualitative, and observational methods were employed in the investigation.…

  15. Racial and Economic Diversity in U.S. Public Montessori Schools

    Science.gov (United States)

    Debs, Mira C.

    2016-01-01

    As public Montessori schools rapidly expand through the United States, the question then arises: What population of students do the schools serve? This study presents a new empirical data set examining the racial and economic diversity of 300 whole-school, public Montessori programs open in 2012-2013, where the entire school uses the Montessori…

  16. Examining a Public Montessori School’s Response to the Pressures of High-Stakes Accountability

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    Corrie Rebecca Block

    2015-11-01

    Full Text Available In order to succeed in the current school assessment and accountability era, a public Montessori school is expected to achieve high student scores on standardized assessments. A problem for a public Montessori elementary school is how to make sense of the school’s high-stakes assessment scores in terms of its unique educational approach. This case study examined a public Montessori elementary school’s efforts as the school implemented the Montessori Method within the accountability era. The research revealed the ways the principal, teachers, and parents on the school council modified Montessori practices, curriculum, and assessment procedures based on test scores. A quality Montessori education is designed to offer children opportunities to develop both cognitive skills and affective components such as student motivation and socio-emotional skills that will serve them beyond their public school experiences. Sadly, the high-stakes testing environment influences so much of public education today. When quality education was measured through only one narrow measure of success the result in this school was clearly a restriction of priorities to areas that were easily assessed.

  17. [Effects of Montessori education on the intellectual development in children aged 2 to 4 years].

    Science.gov (United States)

    He, Hong-Ling; Yan, Hong; Zuo, Ling; Liu, Ling; Zhang, Xi-Ping

    2009-12-01

    To compare the effects of Montessori education and traditional education on the intellectual development in children aged 2 to 4 years. Children aged between 2 to 3 years who were enrolled in a kindergarten in September 2006 were randomly assigned to the Montessori education and the traditional education groups. In addition to receiving the traditional education, the Montessori education group participated in the two-hour Montessori pedagogical activities every day. The intellectual development was evaluated by the Neuropsychological Development Examination Format for Children Aged 0~6 years published by Capital Pediatrics Research Institute at enrollment and one year after the trial. There were no significant differences in the intelligence growth level between the Montessori education and the traditional education groups at enrollment. After one year, the levels of fine movements, adaptation ability, language, and social behavior developments in the Montessori education group were significantly higher than those in the traditional education group (pdevelopment quotient in the Montessori education group were also higher than those in the traditional education group (peducation can promote the development of large motor ability, fine movements, language, and social behavior in children.

  18. Technology in the Montessori Classroom: Teachers' Beliefs and Technology Use

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    Jones, Sara J.

    2017-01-01

    As technology becomes ubiquitous in society, there is increasing momentum to incorporate it into education. Montessori education is not immune to this push for technology integration. This qualitative study investigates four Upper Elementary Montessori teachers' attitudes toward technology and technology integration in a public school setting.…

  19. Objectively measured sedentary behavior in preschool children: comparison between Montessori and traditional preschools

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    Byun Wonwoo

    2013-01-01

    Full Text Available Abstract Background This study aimed to compare the levels of objectively-measured sedentary behavior in children attending Montessori preschools with those attending traditional preschools. Methods The participants in this study were preschool children aged 4 years old who were enrolled in Montessori and traditional preschools. The preschool children wore ActiGraph accelerometers. Accelerometers were initialized using 15-second intervals and sedentary behavior was defined as Results Children attending Montessori preschools spent less time in sedentary behavior than those attending traditional preschools during the in-school (44.4. min/hr vs. 47.1 min/hr, P = 0.03, after-school (42.8. min/hr vs. 44.7 min/hr, P = 0.04, and total-day (43.7 min/hr vs. 45.5 min/hr, P = 0. 009 periods. School type (Montessori or traditional, preschool setting (private or public, socio-demographic factors (age, gender, and socioeconomic status were found to be significant predictors of preschoolers’ sedentary behavior. Conclusions Levels of objectively-measured sedentary behavior were significantly lower among children attending Montessori preschools compared to children attending traditional preschools. Future research should examine the specific characteristics of Montessori preschools that predict the lower levels of sedentary behavior among children attending these preschools compared to children attending traditional preschools.

  20. Montessori and Brain Research.

    Science.gov (United States)

    Hranitz, John R.

    Researchers in medicine, education, and related fields continue to make new discoveries about how the brain functions or malfunctions. The implications of studies of how young children learn compare favorably with those of educators such as Maria Montessori, Jerome Bruner, and Jean Piaget. These researchers saw growth and development as a series…

  1. Square Pegs in Round Holes: Montessori Principals' Perceptions of Science Education in Texas Public Schools

    Science.gov (United States)

    Pollock, Lindsey

    2013-01-01

    The purpose of this phenomenological study was to examine the perceptions of Texas public Montessori school principals as instructional leaders in science. Twelve public Montessori school principals were interviewed for this study. Two research questions were used: How do public Montessori principals perceive Texas science standards in public…

  2. La evaluación docente en la pedagogía Montessori: propuesta de un instrumento A avaliação docente na pedagogia Montessori: proposta de um instrumento Teacher Evaluation in Montessori Education: A Proposed Tool

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    Ana María Mendoza-Páez

    2008-06-01

    Full Text Available El objetivo del presente estudio fue el diseño, la construcción y la validación del contenido de un instrumento que permita evaluar el desempeño docente en un colegio con metodología Montessori. Dicho instrumento se validó a través del método de jueces expertos en relación con la pertinencia, coherencia y redacción de cada ítem (participaron tres jueces; la fiabilidad de los jueces se obtuvo a través del coeficiente de concordancia o índice kappa, el cual puntuó alto (total acuerdo. Conforme a los resultados se eliminaron 27 ítems de los 102 propuestos, y quedaron 75 en el instrumento de aplicación. El instrumento contiene las dimensiones del ser, saber, saber hacer y saber comprender del docente. Posteriormente se hizo una aplicación piloto a los 30 participantes, los cuales pertenecen al colegio Montessori British School, institución que utiliza como pedagogía el método Montessori. En el análisis de la consistencia interna, obtenida por los índices alfa de Cronbach, estos fueron altos en todas las dimensiones evaluadas (promedio .88.Neste artigo, o objetivo foi desenhar, construir e validar o contido de um instrumento que permita avaliar o desempenho docente em uma escola com pedagogia Montessori. Esse instrumento foi validado pelo método de juízes expertos em quanto pertinência, coerência e redação de cada item (participaram três juízes. A fiabilidade dos juízes foi lograda mediante o coeficiente de concordância ou índice de kappa, o qual pontuou alto (acordo total. Seguindo os resultados, foram eliminados 27 itens dos 102 propostos. Os outros 75 permaneceram no instrumento de aplicação. O instrumento contem as dimensões do ser, saber, saber fazer e saber compreender do docente. Depois foi feita uma aplicação piloto aos 30 participantes, pertencentes à escola Montessori British School, instituição que emprega o método Montessori. Na análise da consistência interna, obtida mediante os índices alfa

  3. "It's What We Use as a Community": Exploring Students' STEM Characterizations In Two Montessori Elementary Classrooms

    Science.gov (United States)

    Szostkowski, Alaina Hopkins

    Integrated science, technology, engineering, and mathematics (STEM) education promises to enhance elementary students' engagement in science and related fields and to cultivate their problem-solving abilities. While STEM has become an increasingly popular reform initiative, it is still developing within the Montessori education community. There is limited research on STEM teaching and learning in Montessori classrooms, particularly from student perspectives. Previous studies suggest productive connections between reform-based pedagogies in mainstream science education and the Montessori method. Greater knowledge of this complementarity, and student perspectives on STEM, may benefit both Montessori and non-Montessori educators. This instrumental case study of two elementary classrooms documented student characterizations of aspects of STEM in the context of integrated STEM instruction over three months in the 2016-2017 school year. Findings show that the Montessori environment played an important role, and that students characterized STEM in inclusive, agentive, connected, helpful, creative, and increasingly critical ways. Implications for teaching and future research offer avenues to envision STEM education more holistically by leveraging the moral and humanistic aspects of Montessori philosophy.

  4. Predominantly Black Institutions and Public Montessori Schools: Reclaiming the "Genius" in African American Children

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    Jor'dan, Jamilah R.

    2018-01-01

    There are more than 22,000 Montessori schools in over 100 countries worldwide. Beginning in the 1950s the American Montessori movement was primarily a private pre-school movement. There are more than 5,000 schools in the United States; over 500 of these are public. Montessori schools are an increasingly popular choice in the U.S. for public school…

  5. Best Practice Guidelines for Computer Technology in the Montessori Early Childhood Classroom.

    Science.gov (United States)

    Montminy, Peter

    1999-01-01

    Presents a draft for a principle-centered position statement of a Montessori early childhood program in central Pennsylvania, on the pros and cons of computer use in a Montessori 3-6 classroom. Includes computer software rating form. (Author/KB)

  6. Examining a Public Montessori School's Response to the Pressures of High-Stakes Accountability

    Science.gov (United States)

    Block, Corrie Rebecca

    2015-01-01

    A public Montessori school is expected to demonstrate high student scores on standardized assessments to succeed in the current school accountability era. A problem for a public Montessori elementary school is how to make sense of the school's high-stakes assessment scores in terms of Montessori's unique educational approach. This case study…

  7. Opportunities for Inquiry Science in Montessori Classrooms: Learning from a Culture of Interest, Communication, and Explanation

    Science.gov (United States)

    Rinke, Carol R.; Gimbel, Steven J.; Haskell, Sophie

    2013-08-01

    Although classroom inquiry is the primary pedagogy of science education, it has often been difficult to implement within conventional classroom cultures. This study turned to the alternatively structured Montessori learning environment to better understand the ways in which it fosters the essential elements of classroom inquiry, as defined by prominent policy documents. Specifically, we examined the opportunities present in Montessori classrooms for students to develop an interest in the natural world, generate explanations in science, and communicate about science. Using ethnographic research methods in four Montessori classrooms at the primary and elementary levels, this research captured a range of scientific learning opportunities. The study found that the Montessori learning environment provided opportunities for students to develop enduring interests in scientific topics and communicate about science in various ways. The data also indicated that explanation was largely teacher-driven in the Montessori classroom culture. This study offers lessons for both conventional and Montessori classrooms and suggests further research that bridges educational contexts.

  8. Social Justice Education in an Urban Charter Montessori School

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    Kira Banks

    2016-11-01

    Full Text Available As the Montessori Method continues its expansion in public education, a social justice lens is needed to analyze its contributions and limitations, given the increase in racial and socioeconomic diversity in the United States. Furthermore, much of the work in Social Justice Education (SJE focuses on classroom techniques and curriculum, overlooking the essential work of school administrators and parents, whose work significantly influences the school community. The current study applied an SJE framework to the efforts of one urban, socioeconomically and racially integrated Montessori charter school. We examined the extent to which SJE principles were incorporated across the school community, using an inductive, qualitative, case-study approach that included meetings, surveys, focus groups, and interviews. Administrators quickly adopted a system-wide approach, but parents—often color-blind or minimizing of the relevance of race—consistently resisted. Study results imply a continued need for an institutional approach, not solely a classroom or curricular focus, when integrating social justice into Montessori schools.

  9. Using a Montessori method to increase eating ability for institutionalised residents with dementia: a crossover design.

    Science.gov (United States)

    Lin, Li-Chan; Huang, Ya-Ju; Watson, Roger; Wu, Shiao-Chi; Lee, Yue-Chune

    2011-11-01

    To investigate the efficacy of applying a Montessori intervention to improve the eating ability and nutritional status of residents with dementia in long-term care facilities. An early intervention for eating difficulties in patients with dementia can give them a better chance of maintaining independence and reduce the risk of malnutrition. An experimental crossover design was employed. Twenty-nine residents were chosen from two dementia special care units in metropolitan Taipei. To avoid contamination between participants in units using both Montessori and control interventions, two dementia special care units were randomly assigned into Montessori intervention (I1) and routine activities (I2) sequence groups. A two-period crossover design was used, with 15 residents assigned to Montessori intervention sequence I (I1, I2) and 14 residents assigned to Montessori intervention sequence II (I2, I1). On each intervention day, residents were given their assigned intervention. Montessori intervention was provided in 30-min sessions once every day, three days per week, for eight weeks. There was a two-week washout period between each intervention. There was a significant reduction in the Edinburgh Feeding Evaluation in Dementia score for the Montessori intervention period but not for the routine activities period, while the mean differences for the Eating Behavior Scale score, self-feeding frequency and self-feeding time were significantly higher than those of the routine activities period. Except for the Mini-Nutritional Assessment score post-test being significantly less than the pre-test for the routine activities period, no significant differences for any other variables were found for the routine activities period. This study confirms the efficacy of a Montessori intervention protocol on eating ability of residents with dementia. Adopting Montessori intervention protocols to maintain residents' self-feeding ability in clinical practice is recommended. Montessori

  10. Maria Montessori a different children glance

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    Vittoria Bosna

    2015-02-01

    Full Text Available Maria Montessori was  one of the most important female figures in the 20th-century Italian pedagogical overview. She deeply examined the child and his/her “absorbing” mind in a way that clarified the significant role played by the environment in cognitive and emotional education. Il metodo della pedagogia scientifica (1909 was her first study where she pointed out that science should analyse how the child’s personality develops in social interaction. Maria Montessori claimed children’s rights with respect to the adults’ world by underlining the traditional error -in psychological and educational terms-which used to compel the child to act not complying with his/her own nature. To this end, she organized the child’s educational context-that is the kindergarten- like an ideal place where the child could live his/her educational experiences by freely acting and by being appropriately stimulated. Montessori’s thought has led to fruitful implications related to such pedagogical topics as those currently tackled in contemporary pedagogy: i.e.: the relation between environment and education, the  organization of the teaching and  learning process, the use of procedures, methodologies and materials designed for a relevant pedagogical intervention.How to reference this articleBosna, V. (2015. Maria Montessori uno sguardo diverso sull’infanzia. Foro de Educación, 13(18, pp. 37-50. doi: http://dx.doi.org/10.14516/fde.2015.013.018.002 

  11. Racial Discipline Disproportionality in Montessori and Traditional Public Schools: A Comparative Study Using the Relative Rate Index

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    Katie E. Brown

    2015-11-01

    Full Text Available Research from the past 40 years indicates that African American students are subjected to exclusionary discipline, including suspension and expulsion, at rates two to three times higher than their White peers (Children’s Defense Fund, 1975; Skiba, Michael, Nardo, & Peterson, 2002. Although this phenomenon has been studied extensively in traditional public schools, rates of racially disproportionate discipline in public Montessori schools have not been examined. The purpose of this study is to examine racial discipline disproportionality in Montessori public elementary schools as compared to traditional elementary schools. The Relative Rate Index (RRI is used as a measure of racially disproportionate use of out-of-school suspensions (Tobin & Vincent, 2011. Suspension data from the Office of Civil Rights Data Collection was used to generate RRIs for Montessori and traditional elementary schools in a large urban district in the Southeast. While statistically significant levels of racial discipline disproportionality are found in both the Montessori and traditional schools, the effect is substantially less pronounced in Montessori settings. These findings suggest that Montessori schools are not immune to racially disproportionate discipline and should work to incorporate more culturally responsive classroom management techniques. Conversely, the lower levels of racially disproportionate discipline in the Montessori schools suggests that further study of discipline in Montessori environments may provide lessons for traditional schools to promote equitable discipline.

  12. Determining the Measurement Quality of a Montessori High School Teacher Evaluation Survey

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    Setari, Anthony Philip; Bradley, Kelly D.

    2017-01-01

    The purpose of this study was to conduct a psychometric validation of a course evaluation instrument, known as a student evaluation of teaching (SET), implemented in a Montessori high school. The authors demonstrate to the Montessori community how to rigorously examine the measurement and assessment quality of instruments used within Montessori…

  13. The effect of three different educational approaches on children's drawing ability: Steiner, Montessori and traditional.

    Science.gov (United States)

    Cox, M V; Rowlands, A

    2000-12-01

    Although there is a national curriculum for art education in the UK there are also alternative approaches in the private sector. This paper addresses the issue of the effect of these approaches on children's drawing ability. To compare the drawing ability in three drawing tasks of children in Steiner, Montessori and traditional schools. The participants were 60 school children between the ages of 5;11 and 7;2. Twenty children were tested in each type of school. Each child completed three drawings: a free drawing, a scene and an observational drawing. As predicted, the free and scene drawings of children in the Steiner school were rated more highly than those of children in Montessori and traditional schools. Steiner children's use of colour was also rated more highly, although they did not use more colours than the other children. Steiner children used significantly more fantasy topics in their free drawings. Further observation indicated that the Steiner children were better at using the whole page and organising their drawings into a scene; their drawings were also more detailed. Contrary to previous research Montessori children did not draw more inanimate objects and geometrical shapes or fewer people than other children. Also, contrary to the prediction, Steiner children were significantly better rather than worse than other children at observational drawing. The results suggest that the approach to art education in Steiner schools is conducive not only to more highly rated imaginative drawings in terms of general drawing ability and use of colour but also to more accurate and detailed observational drawings.

  14. Using spaced retrieval and Montessori-based activities in improving eating ability for residents with dementia.

    Science.gov (United States)

    Lin, Li-Chan; Huang, Ya-Ju; Su, Su-Gen; Watson, Roger; Tsai, Belina W-J; Wu, Shiao-Chi

    2010-10-01

    To construct a training protocol for spaced retrieval (SR) and to investigate the effectiveness of SR and Montessori-based activities in decreasing eating difficulty in older residents with dementia. A single evaluator, blind, and randomized control trial was used. Eighty-five residents with dementia were chosen from three special care units for residents with dementia in long-term care facilities in Taiwan. To avoid any confounding of subjects, the three institutions were randomized into three groups: spaced retrieval, Montessori-based activities, and a control group. The invention consisted of three 30-40 min sessions per week, for 8 weeks. After receiving the intervention, the Edinburgh Feeding Evaluation in Dementia (EdFED) scores and assisted feeding scores for the SR and Montessori-based activity groups were significantly lower than that of the control group. However, the frequencies of physical assistance and verbal assistance for the Montessori-based activity group after intervention were significantly higher than that of the control group, which suggests that residents who received Montessori-based activity need more physical and verbal assistance during mealtimes. In terms of the effects of nutritional status after intervention, Mini-Nutritional Assessment (MNA) in the SR group was significantly higher than that of the control group. This study confirms the efficacy of SR and Montessori-based activities for eating difficulty and eating ability. A longitudinal study to follow the long-term effects of SR and Montessori-based activities on eating ability and nutritional status is recommended. Copyright © 2010 John Wiley & Sons, Ltd.

  15. 19th International Montessori Training Course, London Lecture 29 17 November 1933

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    Montessori, Maria

    2016-01-01

    Followers of Maria Montessori become accustomed to the oft-repeated stories that drive home a point, but here is a new treasure. This lecture tells of an experiment that Montessori began with 12- to 14-year-old children and then with 10-year-olds. When the poetry of Dante was introduced to these students, they became passionate and grew to love…

  16. Using acupressure and Montessori-based activities to decrease agitation for residents with dementia: a cross-over trial.

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    Lin, Li-Chan; Yang, Man-Hua; Kao, Chieh-Chun; Wu, Shiao-Chi; Tang, Sai-Hung; Lin, Jaung-Geng

    2009-06-01

    To explore the effectiveness of acupressure and Montessori-based activities in decreasing the agitated behaviors of residents with dementia. A double-blinded, randomized (two treatments and one control; three time periods) cross-over design was used. Six special care units for residents with dementia in long-term care facilities in Taiwan were the sites for the study. One hundred thirty-three institutionalized residents with dementia. Subjects were randomized into three treatment sequences: acupressure-presence-Montessori methods, Montessori methods-acupressure-presence and presence-Montessori methods-acupressure. All treatments were done once a day, 6 days per week, for a 4-week period. The Cohen-Mansfield Agitation Inventory, Ease-of-Care, and the Apparent Affect Rating Scale. After receiving the intervention, the acupressure and Montessori-based-activities groups saw a significant decrease in agitated behaviors, aggressive behaviors, and physically nonaggressive behaviors than the presence group. Additionally, the ease-of-care ratings for the acupressure and Montessori-based-activities groups were significantly better than for the presence group. In terms of apparent affect, positive affect in the Montessori-based-activities group was significantly better than in the presence group. This study confirms that a blending of traditional Chinese medicine and a Western activities program would be useful in elderly care and that in-service training for formal caregivers in the use of these interventions would be beneficial for patients

  17. Montessori-based activities among persons with late-stage dementia: Evaluation of mental and behavioral health outcomes.

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    Wilks, Scott E; Boyd, P August; Bates, Samantha M; Cain, Daphne S; Geiger, Jennifer R

    2017-01-01

    Objectives Literature regarding Montessori-based activities with older adults with dementia is fairly common with early stages of dementia. Conversely, research on said activities with individuals experiencing late-stage dementia is limited because of logistical difficulties in sampling and data collection. Given the need to understand risks and benefits of treatments for individuals with late-stage dementia, specifically regarding their mental and behavioral health, this study sought to evaluate the effects of a Montessori-based activity program implemented in a long-term care facility. Method Utilizing an interrupted time series design, trained staff completed observation-based measures for 43 residents with late-stage dementia at three intervals over six months. Empirical measures assessed mental health (anxiety, psychological well-being, quality of life) and behavioral health (problem behaviors, social engagement, capacity for activities of daily living). Results Group differences were observed via repeated measures ANOVA and paired-samples t-tests. The aggregate, longitudinal results-from baseline to final data interval-for the psychological and behavioral health measures were as follows: problem behaviors diminished though not significantly; social engagement decreased significantly; capacities for activities of daily living decreased significantly; quality of life increased slightly but not significantly; anxiety decreased slightly but not significantly; and psychological well-being significantly decreased. Conclusion Improvements observed for quality of life and problem behaviors may yield promise for Montessori-based activities and related health care practices. The rapid physiological and cognitive deterioration from late-stage dementia should be considered when interpreting these results.

  18. María Montessori y la educación cósmica

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    Juan José Morales Ruiz

    2015-01-01

    Full Text Available La etapa de Montessori en la India fue uno de los periodos más enriquecedores en la vida de MariaMontessori. Allí escribió y publicó La Mente Absorbente del niño, y una serie de libros fundamentales. En suobra La educación de las potencialidades humanas desarrolló los principios de la “Educación Cósmica” queadaptó para el currículo de Primaria. Invitada en 1939 a dar unas conferencias en la India por el Presidente dela Sociedad Teosófica, Montessori y su hijo, se vieron atrapados por el estallido de la Segunda GuerraMundial, y su posterior desarrollo. Tenía 69 años cuando llegó a Madrás. Permaneció diez años. Pero nadasería igual que antes. Había una Montessori antes de la India, y otra mucho más profunda después. Cuandoregresaba a Europa declaró, a los que le preguntaban qué había hecho en la India: “creo que he aprendido aaprender, como el Niño”.

  19. From Boutique to Big Box: A Case Study Concerning Teacher Change Transitioning to a Public Montessori Elementary School

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    Van Acker, Teresa A.

    2013-01-01

    Public Montessori schools have grown in number significantly in the United States. This case study chronicles the journey of teachers as they navigate the tension of balancing the Montessori approach with an accountability Standards model. Although Montessori may be in demand among parents in the nation, exhibited by the increase in public…

  20. Montessori-skole: die ander kant

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    Monica Viljoen

    1995-03-01

    Full Text Available Na aanleiding van die artikel “Die invloed van die New Age-beweging op die onderwysagenda van die toekoms” deur Lien van Niekerk en Corinne Meier van die Departement Historiese Opvoedkunde van Unisa (vgl. Koers, 59 (1 1994:69-84 wil ek graag ’n ander sy van Montessori-skole onder die aandag van Koers lesers bring.

  1. Methods Evolved by Observation

    Science.gov (United States)

    Montessori, Maria

    2016-01-01

    Montessori's idea of the child's nature and the teacher's perceptiveness begins with amazing simplicity, and when she speaks of "methods evolved," she is unveiling a methodological system for observation. She begins with the early childhood explosion into writing, which is a familiar child phenomenon that Montessori has written about…

  2. "Do You Teach Them Anything?" What Really Happens in a Montessori Toddler Class

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    Dore, Heather S.

    2014-01-01

    The greatest sign of success for a teacher is to be able to say, "The children are now working as if I did not exist" (Montessori, 1967, p. 283). Montessori Toddler teachers spend a great amount of time preparing and perfecting their environments to allow and to encourage learning to happen. The teachers are constantly adjusting and…

  3. Assessment of capabilities in persons with advanced stage of dementia: Validation of The Montessori Assessment System (MAS).

    Science.gov (United States)

    Erkes, Jérôme; Camp, Cameron J; Raffard, Stéphane; Gély-Nargeot And, Marie-Christine; Bayard, Sophie

    2017-01-01

    This study evaluated the validity and reliability of the Montessori Assessment System. The Montessori Assessment System assesses preserved abilities in persons with moderate to severe dementia. In this respect, this instrument provides crucial information for the development of effective person-centered care plans. A total of 196 persons with a diagnosis of dementia in the moderate to severe stages of dementia were recruited in 10 long-term care facilities in France. All participants completed the Montessori Assessment System, the Clinical Dementia Rating Scale and/or the Mini Mental State Examination and the Severe Impairment Battery-short form. The internal consistency and temporal stability of the Montessori Assessment System were high. Additionally, good construct and divergent validity were demonstrated. Factor analysis showed a one-factor structure. The Montessori Assessment System demonstrated satisfactory psychometric properties while being a useful instrument to assess capabilities in persons with advanced stages of dementia and hence to develop person-centered plans of care.

  4. PROSES PEMBELAJARAN BERBASIS METODE MONTESSORI DALAM MENGEMBANGKAN KETERAMPILAN SOSIAL ANAK USIA DINI (Penelitian Deskriptif Di PAUD Assya’idiyah Kab. Bandung Barat

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    Agus Sumitra

    2018-01-01

    Full Text Available Pada penelitian ini, penulis mengidentifikasi masalah sebagai berikut: 1. Perencanaan pembelajaran, pengembangan dan proses kegiatan pembelajaran belum mengacu betul terhadap tahap-tahap perkembangan anak, 2. Keterampilan sosial belum tertampilkan secara optimal mengingat sarana dan prasarana yang menunjang pengembangan keterampilan sosial belum memadai, 3. Pembelajaran anak usia dini masih terfokus pada peningkatan kemampuan akademik (hapalan dan calistung, 4. Rasa egois pada diri anak masih tinggi disebabkan cakrawala sosial anak terbatas dirumah, peserta didik seringkali memikirkan diri sendiri. Kemudian penulis merumuskan masalah sebagai berikut: Bagaimana proses pembelajaran metode montessori terhadap keterampilan sosial anak?Berdasarkan pada rumusan masalah di atas, tujuan yang ingin dicapai dalam penelitian ini adalah : 1. Rencana pembelajaran dengan metode montessori dalam upaya meningkatkan keterampilan sosial anak usia dini dengan bermacam aktifitas di PAUD, 2. Pelaksanaan pembelajaran dengan menggunakan metode montessori dalam mengembangkan keterampilan sosial anak usia dini, 3. Evaluasi proses pembelajaran dengan menggunakan metode montessori untuk meningkatkan keterampilan sosiak anak usia dini, 4. Untuk mengembangkan keterampilan sosial anak yang tertampilkan sebagai hasil pembelajaran dengan menggunakan metode montessori pada anak usia dini.Metode yang digunakan oleh penulis dalam penelitian ini adalah metode penelitian deskriptif dengan pendekatan kualitatif untuk mengetahui seberapa besar proses pembelajaran peserta didik dengan menggunakan metode montessori dalam mengembangkan keterampilan sosial anak. Data diperoleh dari hasil observasi, wawancara dan studi dokumentasi terhadap sumber data, objek penelitian yaitu PAUD Assya’idiyah, Kecamatan. Cipongkor, Kabupaten. Bandung Barat.Dari hasil penganalisisan data di peroleh sebagai berikut: 1. Perencanaan pembelajaran di PAUD Assya’idiyah sesuai dengan metode Montessori dimulai

  5. Do Children in Montessori Schools Perform Better in the Achievement Test? A Taiwanese Perspective

    Science.gov (United States)

    Peng, Hsin-Hui; Md-Yunus, Sham'ah

    2014-01-01

    The study examines whether elementary school students in Taiwan who had received Montessori education achieved significantly higher scores on tests of language arts, math, and social studies than students who attended non-Montessori elementary programs. One hundred ninety six children in first, second, and third grade participated in the study.…

  6. [Cognitive disorders and the Montessori method].

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    Lembach, Marie; Agret, Annie; Rochat, Armelle; Thomas, Stéphanie; Jeandel, Claude

    2017-01-01

    Trained in the Montessori method, a team takes a very positive approach to their patients. The nurses base their practice on patients' remaining capacities, helping them work around their impairments. They seek to offer each person the possibility to pursue a social life through individualised treatments. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  7. The American Odyssey of Maria Montessori.

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    Kornegay, William

    Dr. Maria Montessori's 1913 visit and lecture tour to the United SLates is described in detail with numerous citations from newspaper coverage of the event. The enthusiastic reception extended to the European physician and educator is reviewed, and her meetings, notably with Mr. and Mrs. Alexander Graham Bell, President and Mrs. Woodrow Wilson,…

  8. Montessori Elementary Philosophy Reflects Current Motivation Theories

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    Murray, Angela

    2011-01-01

    Montessori's theories, developed more than 100 years ago, certainly resonate with current psychological research on improving education. Autonomy, interest, competence, and relatedness form the foundation for three contemporary efforts to organize the vast literature on motivation into a parsimonious theory. These four elements also comprise…

  9. Escuela integral de desarrollo de liderazgo (EIDL) para el colegio Montessori

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    Velasquez Zapata, Margarita Maria

    2013-01-01

    El propósito de este trabajo es plantear el desarrollo de una escuela de liderazgo para jóvenes preadolescentes y adolescentes del Colegio Montessori, institución de carácter privado, con sede en Medellín. El colegio está centrado en el planteamiento de un proyecto en la temática del liderazgo escolar, a partir del diseño de un programa de desarrollo de liderazgo para jóvenes del Colegio Montessori de Medellín, teniendo en cuenta los elementos conceptuales, procedimentales y estratégicos ...

  10. La función y el papel desempeñado por la maestra en la obra de Montessori - The role and the function of the teacher in Montessori works

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    Alessandra Avanzini

    2011-03-01

    Full Text Available A FUNÇÃO  E O PAPEL DESEMPENHADO PELA PROFESSORA NA OBRA DE MONTESSORI Resumo A função da professora constitui um aspecto fundamental dentro do sistema  teórico  montessoriano.   De   fato,   Montessori  atribui   à professora um papel muito  delicado: facilitar o correto crescimento da criança “pai  do homem”. É  por isto que o papel e a função da professora montessoriana devem responder aos pontos  fortes de sua teoria educativa: a necessidade de que haja uma forte idéia de escola, a necessidade de diferenciar o momento teórico do momento prático e o papel desempenhado pelo desempenho científico da professora; o respeito que ambos devem ter com a criança (nem a professora nem a ciência  podem  fixar  a   priori   os   resultados  de  cada  criança: potencialmente  a   excelência é  para  todos;  o  xeque  a  qualquer pretensão de neutralidade/objetividade: quando a relação é com seres humanos  é  sem  sentido  pensar  que  existam  técnicos  capazes de transmitir conceitos de maneira asséptica. Como dito anteriormente, a professora em  Montessori se pode definir como um  técnico, no sentido de que não é o científico a que lê corresponde a  elaboração teórica  senão  técnico.  Um  técnico  que  não  é  nem  neutro  nem asséptico e cuja humanidade se colocará em um primeiro plano para que possa levar a cabo seu próprio trabalho o melhor possível. Palavras-chave: Montessori; didática; professora.   THE ROLE AND THE FUNCTION  OF THE TEACHER IN MONTESSORI WORKS Abstract The function of the teacher constitutes a fundamental aspect inside Montessori's system of thought. She offers to teacher a very delicate role, that of helping the right growth of child as "man's father". For this reason the  role and the function  of Montessori teacher must correspond to the principle points of her educative theory, that is to say: the necessity to have a

  11. Maria Montessori (1870-1952): Women's emancipation, pedagogy and extra verbal communication.

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    Cascella, Marco

    2015-05-01

    Maria Montessori is one of the most well-known women in Italian history. Although she was the first woman who graduated in medicine in Italy, she is mostly known as an educator. Her teaching method--the Montessori Method- is still used worldwide--Because she could not speak English during the imprisonment in India, there was a big obstacle for her communication with children. However, the need to adopt a non-verbal communication, led her to a sensational discovery: children use an innate and universal language. This language, made of gestures and mimic, is called extra verbal communication.

  12. Study protocol: A Montessori approach to dementia-related, non-residential respite services in Australia.

    Science.gov (United States)

    Hanna, Andrew; Donnelly, James; Aggar, Christina

    2018-03-27

    Given the social burden and significant cost of dementia care in Australia, finding evidence-based approaches that improve outcomes, maintain independence, and reduce the impact on patients and families is essential. Finding effective ways to train and assist the healthcare staff who support these individuals is also critical, as they are considered to be at risk of workplace stress, burnout, and other psychological disturbances which negatively affects standards of care. The current paper describes a protocol for evaluating the effects of a Montessori-based approach to dementia care, in non-residential respite centres. An 18 month prospective observational, cohort controlled design is suggested that will compare participants from a community respite service that has undergone a Montessori-based workplace culture change and those from a service that provides a person-centred 'care as usual' approach. To achieve this, the protocol includes the assessment of participants across multiple variables on a monthly basis including the cognitive, behavioural, and emotional functioning of clients with dementia, levels of caregiver burden experienced by informal carers, and burnout, compassion satisfaction and workplace engagement among respite staff. The protocol also employs a qualitative evaluation of program fidelity. This approach will provide further insight into the potential benefits of early intervention with Montessori approaches for persons living with dementia in the community, their caregivers, and the staff and volunteers who assist them. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Music Education in Montessori Schools: An Exploratory Study of School Directors' Perceptions in the United States

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    Rajan, Rekha S.

    2017-01-01

    This exploratory study examined the changing role of music education and the availability of musical experiences for students attending Montessori schools in the Midwestern United States. On a survey instrument designed by the researcher, Montessori school directors (N = 36) from eight states shared descriptions of the current role of music at…

  14. Why Montessori? Answers from a Parent's Perspective

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    Karna, Anu

    2013-01-01

    The author knew she would be picky about where her child started his schooling. After calling over 30 public and private schools within a 50-mile radius of her home, and then visiting more than 15 of them, the author chose Lexington Montessori School (LMS). However, when she tells friends and acquaintances about her son's fantastic school, she…

  15. Educational Gymnastics: The Effectiveness of Montessori Practical Life Activities in Developing Fine Motor Skills in Kindergartners

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    Bhatia, Punum; Davis, Alan; Shamas-Brandt, Ellen

    2015-01-01

    Research Findings: A quasi-experiment was undertaken to test the effect of Montessori practical life activities on kindergarten children's fine motor development and hand dominance over an 8-month period. Participants were 50 children age 5 in 4 Montessori schools and 50 students age 5 in a kindergarten program in a high-performing suburban…

  16. Successful applications of montessori methods with children at risk for learning disabilities.

    Science.gov (United States)

    Pickering, J S

    1992-12-01

    The critical elements in the Montessori philosophy are respect for the child, individualization of the program to that child, and the fostering of independence. With her research background, Maria Montessori devised a multisensory developmental method and designed materials which isolate each concept the teacher presents to the child.In presenting these materials the teacher observes the concept and skill development level of the child, ascertaining areas of strength and weakness and matching the next presentation to the child's level of development. Using small sequential steps, the teacher works to ameliorate weakness and guide the student to maximize his strengths. These presentations, usually initiated by the child, enhance cognitive growth using a process which integrates his physical, social, and emotional development.The curriculum contains four major content areas: Practical Life; Sensorial; Oral and Written Language; and Mathematics. Geography, History, Science, Art, Music, Literature, and Motor Skills are also included. In all of these the Montessori presentations build from the simple to the complex, from the concrete to the abstract, and from percept to concept. Vocabulary and language usage are integral to each presentation.The procedures introduced through these presentations are designed to enhance attention, increase self-discipline and self-direction, and to promote order, organization, and the development of a work cycle. At-risk children benefit from the structure, the procedures, and the curriculum. Applications of this method require more teacher selection of materials and direct teaching, particularly of language and math symbols and their manipulations.This early childhood intervention provides an individualized program which allows the at-risk child a successful experience at the preschool level. The program includes a strong conceptual preparation for later academic learning and it promotes the development of a healthy self-concept.

  17. Effects of intergenerational Montessori-based activities programming on engagement of nursing home residents with dementia

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    Michelle M Lee

    2007-10-01

    Full Text Available Michelle M Lee1, Cameron J Camp2, Megan L Malone21Midwestern University, Department of Behavioral Medicine, Downers Grove, IL , USA; 2Myers Research Institute of Menorah Park Center for Senior Living, Beachwood, OH, USA Abstract: Fourteen nursing home residents on a dementia special care unit at a skilled nursing facility took part in one-to-one intergenerational programming (IGP with 15 preschool children from the facility’s on-site child care center. Montessori-based activities served as the interface for interactions between dyads. The amount of time residents demonstrated positive and negative forms of engagement during IGP and standard activities programming was assessed through direct observation using a tool developed for this purpose – the Myers Research Institute Engagement Scale (MRI-ES. These residents with dementia displayed the ability to successfully take part in IGP. Most successfully presented “lessons” to the children in their dyads, similar to the way that Montessori teachers present lessons to children, while persons with more severe cognitive impairment took part in IGP through other methods such as parallel play. Taking part in IGP was consistently related with higher levels of positive engagement and lower levels of negative forms of engagement in these residents with dementia than levels seen in standard activities programming on the unit. Implications of using this form of IGP, and directions for future research, are discussed.Keywords: Montessori-based activities, intergenerational programming, engagement, dementia

  18. Montessori Early Childhood Teacher Perceptions of Family Priorities and Stressors

    Directory of Open Access Journals (Sweden)

    Ann Epstein

    2015-11-01

    Full Text Available Teachers of young children work closely with families. One component of teacher-family partnerships is teachers’ understanding of family priorities and stressors. This study examines Montessori early childhood (ages three through six teacher perceptions of family priorities and stressors through an analysis of responses to two parallel surveys.  Eighty teachers (37% of those who received the survey and forty-nine family members (representing a 55% response rate completed the survey.  Significant differences were found between teachers’ perceptions of four (of seven family priorities and families’ actual responses. Teachers ranked “making academic progress” as the most important of seven possible family priorities. However, families stated that “developing kindness” is the most important priority for their young children. No significant differences were found when comparing teacher rankings of family stressors with actual family responses. Montessori early childhood teachers ranked “not having enough time” as the most stressful of six possible stressors. Families confirmed that time pressures cause them the most stress. Maria Montessori’s recommendations for teachers and families are summarized. Recommendations for building stronger family partnerships in the context of Montessori’s philosophy, for example on-going self-reflection, are provided.             Keywords: Montessori, teacher-family partnerships, early childhood teacher perceptions

  19. Montessori and Steiner: A Pattern of Reverse Symmetries.

    Science.gov (United States)

    Coulter, Dee Joy

    2003-01-01

    Explains the educational movements precipitated by Maria Montessori and Rudolf Steiner as comprising a pattern of reverse symmetries. Notes the influence of war on their philosophies. Discusses reverse symmetries in curriculum related to mathematics, geography, and history. Maintains that each of these two movements holds the other at its core,…

  20. The profile of the Montessori assistant: historical paths and new education projects

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    Barbara De Serio

    2016-07-01

    Full Text Available This paper looks at the professional profile of the Montessori-trained teacher, as educated at the college devised by Maria Montessori and founded in the 1950s by one of her closest pupils, Adele Costa Gnocchi. The Montessori assistant was a professional figure specially trained to aid the birth process and the “mental” needs of the protagonists involved, referring specifically to the child. In this respect, the paper also looks at the subject of education from birth, starting with Montessori’s earliest ideas on new-born children and their creative capabilities. The purpose is to recover the scientific foundations on which the pedagogical practices usually applied by childhood services are based, with the awareness that these consolidated practices need strengthening and a scientific foundation – including on an historical level – in order to contribute to qualifying services for early childhood. Through specific methodological qualification, above all with regard to Montessori’s methods, as well as by placing more valid historical importance on the paths they began, early childhood services may even be able to move in the direction of possible institutionalised training.

  1. ICTs and Montessori for Learning Disabilities

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    Athanasios Drigas

    2017-10-01

    Full Text Available This paper concentrates on the Montessori philosophy and examines how this learning theory currently gives credence to cognitive processes of the mind, as suitable intervention used to the training of children with learning disabilities. Furthermore, Montessori’s system and materials in combination with the support of new technologies as well as their implementation on various kinds of Information and Communication Technologies (ICTs have great successes regarding the support of disability and the enhancement of learning process.

  2. La función y el papel desempeñado por la maestra en la obra de Montessori - The role and the function of the teacher in Montessori works

    OpenAIRE

    Alessandra Avanzini

    2011-01-01

    A FUNÇÃO  E O PAPEL DESEMPENHADO PELA PROFESSORA NA OBRA DE MONTESSORI Resumo A função da professora constitui um aspecto fundamental dentro do sistema  teórico  montessoriano.   De   fato,   Montessori  atribui   à professora um papel muito  delicado: facilitar o correto crescimento da criança “pai  do homem”. É  por isto que o papel e a função da professora montessoriana devem responder aos pontos  fortes de sua teoria educativa: a necessidade de que haja uma forte idéia de escola, a necess...

  3. Task-based Language Learning in Bilingual Montessori Elementary Schools: Customizing Foreign Language Learning and Promoting L2 Speaking Skills

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    Jana Winnefeld

    2012-01-01

    Full Text Available Foreign language learning has been a part of German elementary schools for several years now. Montessori schools focusing on individual learning, i.e. mostly independent from the teacher and based on auto-education, interest, and free choice, are also asked to teach an L2. The original lack of a concept of L2 learning for this environment has brought forth different approaches. Bilingual education seems to be feasible and applicable in Montessori education. The downside to this is that even in a bilingual classroom the Montessori way of learning may not allow for very much oral production of the foreign language. The role of L2 production (cf. Swain 1985, 1995, 2005 for language acquisition has been theoretically claimed and empirically investigated. Output can have a positive influence on L2 learning (cf. e.g. Izumi 2002, Keck et al. 2006. This also applies to interaction (cf. Long 1996, where negotiation of meaning and modified output are factors supporting L2 development (cf. e.g. de la Fuente 2002, McDonough 2005. Task-based Language Learning (TBLL presents itself as one way to promote oral language production and to provide opportunities for meaning-negotiation. Especially tasks with required information exchange and a closed outcome have been shown to be beneficial for the elicitation of negotiation of meaning and modified output. This paper argues that TBLL is a promising approach for the facilitation of L2 production and thus the development of speaking skills in a Montessori context. It also hypothesizes that TBLL can be implemented in a bilingual Montessori environment while still making the Montessori way of learning possible. Different tasks on various topics, examples of which are presented in this article, can lay the foundation for this. Offering such tasks in a bilingual Montessori elementary classroom promises to foster language production and the use of communication strategies like negotiation of meaning, both being

  4. What Makes Mathematics Manipulatives Effective? Lessons From Cognitive Science and Montessori Education

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    Elida V. Laski

    2015-06-01

    Full Text Available Manipulatives are ubiquitous in early childhood classrooms; yet, findings regarding their efficacy for learning mathematics concepts are inconsistent. In this article, we present four general principles that have emerged from cognitive science about ways to ensure that manipulatives promote learning when used with young children. We also describe how Montessori instruction offers a concrete example of the application of these principles in practice, which may, in turn, explain the high levels of mathematics achievement among children who attend Montessori programs during early childhood. The general principles and concrete examples presented in this article should help early childhood programs maximize the benefits of using manipulatives for developmentally appropriate mathematics instruction.

  5. Three Approaches from Europe: Waldorf, Montessori, and Reggio Emilia.

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    Edwards, Carolyn Pope

    2002-01-01

    Waldorf, Montessori, and Reggio Emilia are three progressive approaches to early childhood education that appear to be growing in influence in North America and to have many points in common. This article provides a brief comparative introduction of these models and highlights several key areas of similarity and contrast. All three approaches…

  6. Aspects That Arise in the Transition from the Montessori Method to a Traditional Method: A Fourth Grade Mathematics View

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    Hurdle, Zachariah B.

    2017-01-01

    The purpose of the dissertation is to investigate three particular aspects that may affect the transition between a third grade Montessori system and a fourth grade non-Montessori system, specifically within the context of teaching and learning mathematics. These aspects are 1) the change in pacing and structure of the classroom, 2) the removal of…

  7. Think Big: Leadership Projects for AMS and Montessori Educators

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    Chattin-McNichols, John

    2014-01-01

    The American Montessori Society's (AMS) 2014 Living Legacy recipient, John Chattin-McNichols, delivered the keynote address at the Annual Conference in Dallas, TX, on March 27, 2014, In his speech, he described three overall highlights of AMS: (1) AMS is now a world-leading organization; (2) It must become a learning organization; and (3)…

  8. Differences in Mathematics Scores Between Students Who Receive Traditional Montessori Instruction and Students Who Receive Music Enriched Montessori Instruction

    OpenAIRE

    Harris, Maureen Ann

    2007-01-01

    While a growing body of research reveals the beneficial effects of music on education performance the value of music in educating the young child is not being recognized. If research of students in the school system indicates that learning through the arts can benefit the ‘whole’ child, that math achievement scores are significantly higher for those students studying music, and if Montessori education produces a more academically accomplished child, then what is the potential for the child wh...

  9. Montessori Early Childhood Teacher Perceptions of Family Priorities and Stressors

    Science.gov (United States)

    Epstein, Ann

    2015-01-01

    Teachers of young children work closely with families. One component of teacher-family partnerships is teachers' understanding of family priorities and stressors. This study examines Montessori Early Childhood (ages three through six) teacher perceptions of family priorities and stressors through an analysis of responses to two parallel surveys.…

  10. Effects of intergenerational Montessori-based activities programming on engagement of nursing home residents with dementia.

    Science.gov (United States)

    Lee, Michelle M; Camp, Cameron J; Malone, Megan L

    2007-01-01

    Fourteen nursing home residents on a dementia special care unit at a skilled nursing facility took part in one-to-one intergenerational programming (IGP) with 15 preschool children from the facility's on-site child care center. Montessori-based activities served as the interface for interactions between dyads. The amount of time residents demonstrated positive and negative forms of engagement during IGP and standard activities programming was assessed through direct observation using a tool developed for this purpose--the Myers Research Institute Engagement Scale (MRI-ES). These residents with dementia displayed the ability to successfully take part in IGP. Most successfully presented "lessons" to the children in their dyads, similar to the way that Montessori teachers present lessons to children, while persons with more severe cognitive impairment took part in IGP through other methods such as parallel play. Taking part in IGP was consistently related with higher levels of positive engagement and lower levels of negative forms of engagement in these residents with dementia than levels seen in standard activities programming on the unit. Implications of using this form of IGP, and directions for future research, are discussed.

  11. Implementing Montessori Methods for Dementia™ in Ontario long-term care homes: Recreation staff and multidisciplinary consultants' perceptions of policy and practice issues.

    Science.gov (United States)

    Ducak, Kate; Denton, Margaret; Elliot, Gail

    2018-01-01

    Montessori-based activities use a person-centred approach to benefit persons living with dementia by increasing their participation in, and enjoyment of, daily life. This study investigated recreation staff and multidisciplinary consultants' perceptions of factors that affected implementing Montessori Methods for Dementia™ in long-term care homes in Ontario, Canada. Qualitative data were obtained during semi-structured telephone interviews with 17 participants who worked in these homes. A political economy of aging perspective guided thematic data analysis. Barriers such as insufficient funding and negative attitudes towards activities reinforced a task-oriented biomedical model of care. Various forms of support and understanding helped put Montessori Methods for Dementia™ into practice as a person-centred care program, thus reportedly improving the quality of life of residents living with dementia, staff and family members. These results demonstrate that when Montessori Methods for Dementia™ approaches are learned and understood by staff they can be used as practical interventions for long-term care residents living with dementia.

  12. Montessori Botany Studies: Why It Is Time for a Change.

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    Coe, Elisabeth; Spears, Priscilla

    2002-01-01

    Discusses the need to change the Montessori botany nomenclature cards to reflect the progress of the field over the past 55 years. Maintains that the materials used should reflect the goals of botany study for children. Provides a sample outline of lessons and nomenclature for the flowering plants. Discusses the need to use available reference…

  13. Children’s stories in the educational theories of Ellen Key, Rudolf Steiner and Maria Montessori

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    William Grandi

    2016-11-01

    Full Text Available The article explores the educational value that Ellen Key (1849-1926, Rudolf Steiner (1861-1925 and Maria Montessori (1870-1952 attributed to children's stories. In the late nineteenth and early twentieth century these three important authors contributed to the renewal of the educational theories and practices. They dedicated a part of their pedagogical reflections to the educational meanings of children's stories; consider, e.g., the many pages of Ellen Key on children's literature, the recommendations of Rudolf Steiner on the educational relevance of fairy tales and mythology or, finally, Maria Montessori's reflections on fairy tales. The article examines these ideas from a historical and pedagogical point of view.

  14. Implementing a Robotics Curriculum in an Early Childhood Montessori Classroom

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    Elkin, Mollie; Sullivan, Amanda; Bers, Marina Umaschi

    2014-01-01

    This paper explores how robotics can be used as a new educational tool in a Montessori early education classroom. It presents a case study of one early educator's experience of designing and implementing a robotics curriculum integrated with a social science unit in her mixed-age classroom. This teacher had no prior experience using robotics in…

  15. A randomized crossover trial to study the effect of personalized, one-to-one interaction using Montessori-based activities on agitation, affect, and engagement in nursing home residents with Dementia.

    Science.gov (United States)

    van der Ploeg, Eva S; Eppingstall, Barbara; Camp, Cameron J; Runci, Susannah J; Taffe, John; O'Connor, Daniel W

    2013-04-01

    Increasingly more attention has been paid to non-pharmacological interventions as treatment of agitated behaviors that accompany dementia. The aim of the current study is to test if personalized one-to-one interaction activities based on Montessori principles will improve agitation, affect, and engagement more than a relevant control condition. We conducted a randomized crossover trial in nine residential facilities in metropolitan Melbourne, Australia (n = 44). Personalized one-to-one activities that were delivered using Montessori principles were compared with a non-personalized activity to control for the non-specific benefits of one-to-one interaction. Participants were observed 30 minutes before, during, and after the sessions. The presence or absence of a selected physically non-aggressive behavior was noted in every minute, together with the predominant type of affect and engagement. Behavior counts fell considerably during both the Montessori and control sessions relative to beforehand. During Montessori activities, the amount of time spend actively engaged was double compared to during the control condition and participants displayed more positive affect and interest as well. Participants with no fluency in English (all from non-English speaking backgrounds) showed a significantly larger reduction in agitation during the Montessori than control sessions. Our results show that even non-personalized social contact can assist in settling agitated residents. Tailoring activities to residents' needs and capabilities elicit more positive interactions and are especially suitable for people who have lost fluency in the language spoken predominantly in their residential facility. Future studies could explore implementation by family members and volunteers to avoid demands on facilities' resources. Australian New Zealand Clinical Trials Registry - ACTRN12609000564257.

  16. Montessori Public School Pre-K Programs and the School Readiness of Low-Income Black and Latino Children.

    Science.gov (United States)

    Ansari, Arya; Winsler, Adam

    2014-11-01

    Within the United States, there are a variety of early education models and curricula aimed at promoting young children's pre-academic, social, and behavioral skills. This study, using data from the Miami School Readiness Project (MSRP; Winsler et al., 2008, 2012), examined the school readiness gains of low-income Latino ( n = 7,045) and Black children ( n = 6,700) enrolled in two different types of Title-1 public school pre-K programs: those in programs using the Montessori curricula and those in more conventional programs using the High/Scope curricula with a literacy supplement. Parents and teachers reported on children's socio-emotional and behavioral skills with the Devereux Early Childhood Assessment (DECA), while children's pre-academic skills (cognitive, motor, and language) were assessed directly with the Learning Accomplishment Profile Diagnostic (LAP-D) at the beginning and end of their four-year-old pre-K year. All children, regardless of curricula, demonstrated gains across pre-academic, socio-emotional, and behavioral skills throughout the pre-K year; however, all children did not benefit equally from Montessori programs. Latino children in Montessori programs began the year at most risk in pre-academic and behavioral skills, yet exhibited the greatest gains across these domains and ended the year scoring above national averages. Conversely, Black children exhibited healthy gains in Montessori, but demonstrated slightly greater gains when attending more conventional pre-K programs. Findings have implications for tailoring early childhood education programs for Latino and Black children from low-income communities.

  17. John McDermott and the Road to Montessori Public Schools

    Science.gov (United States)

    Povell, Phyllis

    2014-01-01

    In this article, the author states that, for over 45 years, she has explored the issues of leadership and change, and, along the way, she has examined how diversity fits in with these ideas. She states that she found all three of these concepts embodied in the person of John McDermott, a leader in the American Montessori movement in the United…

  18. The Effects of Music Instruction on Learning in the Montessori Classroom

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    Harris, Maureen

    2008-01-01

    The value of music in educating the young child is not being recognized, particularly in the area of mathematics. Despite the amount of literature available regarding the effects of music instruction on academic achievement, little has been written on different Montessori music pedagogies and their effects on students' math scores. This article…

  19. La progettazione di nuovi spazi educativi per l’infanzia: da Ellen Key a Maria Montessori

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    Tiziana Pironi

    2011-11-01

    Full Text Available The essay presents a comparison between the thought of Ellen Key and that of Maria Montessori. Changes that involved the role of women, caught in its interdependence with the development of new educational practices, were the center of the theoretical contribution of Ellen Key. Maria Montessori believed that only women work outside the home would guarantee the economic independence necessary to form a union on sentiment rather than on utilitarian calculations and therefore she did not seem to share the concerns of the Key on an increasingly massive female entry into the world of work. The paper offers an updated reflection on the work of two scholars of education.

  20. The Effect of Montessori Method on Cognitive Tempo of Kindergarten Children

    Science.gov (United States)

    Kayili, Gökhan

    2018-01-01

    This study was undertaken to discover the effect of the Montessori Method on the cognitive tempo of 4-5-year-old children. Using an experimental pre-test-post-test paired control group design, the study sample included 60 children attending Ihsan Dogramaci Applied Nursery School (affiliated to Selcuk University, Department of Health Sciences) in…

  1. Mind over Matter: Contributing Factors to Self-Efficacy in Montessori Teachers

    Science.gov (United States)

    Bhatia, Punum

    2012-01-01

    Interpreting Albert Bandura's term "self-efficacy" as the individual's belief in his own abilities to succeed in spite of the given circumstances, this study seeks to identify the influences which lead to self-efficacy in Montessori teachers. In order to evaluate perceptions of self-efficacy, 35 pre-service teachers in the…

  2. Homework Policy and Student Choice: Findings from a Montessori Charter School

    Science.gov (United States)

    Scott, Catherine M.; Glaze, Nelda

    2017-01-01

    The use of homework has been a controversial topic in education for many years: what types of homework to give, how much, and how often. In previous years, Ocean Montessori School (a pseudonym), the site of this study, offered homework like that of traditional public schools, such as worksheets and rote skill practice. Feeling conflicted about the…

  3. Trends in Personal Belief Exemption Rates Among Alternative Private Schools: Waldorf, Montessori, and Holistic Kindergartens in California, 2000-2014.

    Science.gov (United States)

    Brennan, Julia M; Bednarczyk, Robert A; Richards, Jennifer L; Allen, Kristen E; Warraich, Gohar J; Omer, Saad B

    2017-01-01

    To evaluate trends in rates of personal belief exemptions (PBEs) to immunization requirements for private kindergartens in California that practice alternative educational methods. We used California Department of Public Health data on kindergarten PBE rates from 2000 to 2014 to compare annual average increases in PBE rates between schools. Alternative schools had an average PBE rate of 8.7%, compared with 2.1% among public schools. Waldorf schools had the highest average PBE rate of 45.1%, which was 19 times higher than in public schools (incidence rate ratio = 19.1; 95% confidence interval = 16.4, 22.2). Montessori and holistic schools had the highest average annual increases in PBE rates, slightly higher than Waldorf schools (Montessori: 8.8%; holistic: 7.1%; Waldorf: 3.6%). Waldorf schools had exceptionally high average PBE rates, and Montessori and holistic schools had higher annual increases in PBE rates. Children in these schools may be at higher risk for spreading vaccine-preventable diseases if trends are not reversed.

  4. Elementary Teachers' Perceptions of Mathematics Instruction in Montessori and Traditional Classrooms

    Science.gov (United States)

    Kofa, Linda

    2017-01-01

    Students in grades 3 and 4 attending a traditional public elementary school in a northeastern state did not meet proficiency levels in mathematics as measured by the state's assessment system. Published reports indicated that students attending the Montessori programs were more proficient in solving math problems compared to students in…

  5. The Epistemology behind the Educational Philosophy of Montessori: Senses, Concepts, and Choice

    Science.gov (United States)

    Colgan, Andrew D.

    2016-01-01

    This article seeks to re-introduce Dr. Maria Montessori's educational philosophy, which has been absent from modern philosophy of education literature. It describes and analyzes crucial aspects of her epistemology, as best known through her "Method." Discussed are the need for early education, the development of the senses, and the…

  6. An intergenerational program for persons with dementia using Montessori methods.

    Science.gov (United States)

    Camp, C J; Judge, K S; Bye, C A; Fox, K M; Bowden, J; Bell, M; Valencic, K; Mattern, J M

    1997-10-01

    An intergenerational program bringing together older adults with dementia and preschool children in one-on-one interactions is described. Montessori activities, which have strong ties to physical and occupational therapy, as well as to theories of developmental and cognitive psychology, are used as the context for these interactions. Our experience indicates that older adults with dementia can still serve as effective mentors and teachers to children in an appropriately structured setting.

  7. Maria Montessori e seu método

    OpenAIRE

    Suelu Pereira Costa, Magda

    2012-01-01

    Neste artigo, a autora desenvolve reflexões sobre o Método Montessori, que há um século, por volta de 1907, já propunha uma educação libertadora para a criança, valorizando-a como um ser pensante e capaz de responder aos apelos do real, visando a formação de uma personalidade autônoma e do Homem Consciente. Esse método, além de adotar uma perpectiva filosófica e metodológica para atender a criança, construindo materiais pedagógicos específicos e estratégias pcdagógicas. introduz a a "Linh...

  8. [The significance of the Montessori method and phenomenon with a particular view to the therapy of the aphasics (author's transl)].

    Science.gov (United States)

    Birchmeier-Nussbaumer, A K

    1980-05-01

    The methods of the Italian physician Maria Montessori influenced the development of modern learning practices. There is general agreement that the Montessori phenomenon is personality forming. Aspects of this method, which are relevant for the rehabilitation of the brain-damaged and, in particular, the aphasics are presented. Possible shifts of emphasis within the relationship therapist - method - patient are analysed. Examples are used to outline in how far an increasingly patient-oriented therapy can influence the development of the aphasic patient.

  9. Theories of Childhood: An Introduction to Dewey, Montessori, Erikson, Piaget & Vygotsky, Second Edition

    Science.gov (United States)

    Mooney, Carol Garhart

    2013-01-01

    This best-selling resource provides clear, straightforward introductions to the foundational theories of John Dewey, Maria Montessori, Erik Erikson, Jean Piaget, and Lev Vygotsky. Each chapter highlights a theorist's work and includes insight on how the theory impacts teaching young children today. Discussion questions and suggested readings are…

  10. Social Work in Family Life Enrichment: The Children of Alcoholics--A Montessori Approach

    Science.gov (United States)

    McDonald-Jay, Celynn

    1978-01-01

    If the children of alcoholics are to break the alcoholic life style cycle, they must develop their potential for creativity, initiative, independence, inner discipline, and self confidence. The Montessori approach is particularly successful in achieving these qualities in children and in promoting parenting skills in alcoholic parents. (Author/GC)

  11. The Mystery of Pleasure: Thoughts on Teaching and learning Sex and Gender Relations in a Democratic Montessori Elementary Environment

    Directory of Open Access Journals (Sweden)

    Matthew Henry R. RICH

    2007-07-01

    Full Text Available Dr Maria Montessori (1870-1952, saw the child as a 'spiritual embryo' naturally gravitating towards a state of 'normalization' through the evolving discovery of a 'cosmic task' that emerged from inquiring into one's identity and role in the universe. Although she laid a philosophical framework for this 'educating of the human potential'; she never openly discussed sexuality and sexual knowledge as a necessary part of this development. Dr Riane Eisler is a contemporary feminist systems theorist whose 'partnership model' of sexual politics embraces (and, in fact, openly endorses the tenets of the Montessori approach.

  12. Un-"Chartered" Waters: Balancing Montessori Curriculum and Accountability Measures in a Charter School

    Science.gov (United States)

    Scott, Catherine M.

    2017-01-01

    More than 6,000 charter schools exist in the United States, and of these 120 are Montessori charter schools. When studying charter school practices, researchers often examine issues such as performance accountability measures and effectiveness of charter school curricula. In doing so, the outcomes often overlook the challenges for teachers as they…

  13. Longitudinal Academic Achievement Outcomes: Modeling the Growth Trajectories of Montessori Elementary Public School Students

    Science.gov (United States)

    Mallett, Jan Davis

    2014-01-01

    Elementary education has theoretical underpinnings based on cognitive psychology. Ideas from cognitive psychologists such as James, Dewey, Piaget, and Vygotsky coalesce to form constructivism (Cooper, 1993; Yager, 2000; Yilmaz, 2011). Among others, the Montessori Method (1912/1964) is an exemplar of constructivism. Currently, public education in…

  14. Trends in Personal Belief Exemption Rates Among Alternative Private Schools: Waldorf, Montessori, and Holistic Kindergartens in California, 2000–2014

    Science.gov (United States)

    Bednarczyk, Robert A.; Richards, Jennifer L.; Allen, Kristen E.; Warraich, Gohar J.; Omer, Saad B.

    2017-01-01

    Objectives. To evaluate trends in rates of personal belief exemptions (PBEs) to immunization requirements for private kindergartens in California that practice alternative educational methods. Methods. We used California Department of Public Health data on kindergarten PBE rates from 2000 to 2014 to compare annual average increases in PBE rates between schools. Results. Alternative schools had an average PBE rate of 8.7%, compared with 2.1% among public schools. Waldorf schools had the highest average PBE rate of 45.1%, which was 19 times higher than in public schools (incidence rate ratio = 19.1; 95% confidence interval = 16.4, 22.2). Montessori and holistic schools had the highest average annual increases in PBE rates, slightly higher than Waldorf schools (Montessori: 8.8%; holistic: 7.1%; Waldorf: 3.6%). Conclusions. Waldorf schools had exceptionally high average PBE rates, and Montessori and holistic schools had higher annual increases in PBE rates. Children in these schools may be at higher risk for spreading vaccine-preventable diseases if trends are not reversed. PMID:27854520

  15. The Montessori Method and the Kindergarten. Bulletin, 1914, No. 28. Whole Number 602

    Science.gov (United States)

    Harrison, Elizabeth

    1914-01-01

    Recently an earnest, brilliant, and learned Italian woman, Dr. Maria Montessori, has become famous, probably beyond her desire, for her contribution to the knowledge of little children and for the embodiment of her own and the discoveries of others in what she likes to call "a method of a new science of education." Her scientific investigations as…

  16. Construction and Validation of a Holistic Education School Evaluation Tool Using Montessori Erdkinder Principles

    Science.gov (United States)

    Setari, Anthony Philip

    2016-01-01

    The purpose of this study was to construct a holistic education school evaluation tool using Montessori Erdkinder principles, and begin the validation process of examining the proposed tool. This study addresses a vital need in the holistic education community for a school evaluation tool. The tool construction process included using Erdkinder…

  17. The Effect of Steiner, Montessori, and National Curriculum Education upon Children's Pretence and Creativity

    Science.gov (United States)

    Kirkham, Julie Ann; Kidd, Evan

    2017-01-01

    Pretence and creativity are often regarded as ubiquitous characteristics of childhood, yet not all education systems value or promote these attributes to the same extent. Different pedagogies and practices are evident within the UK National Curriculum, Steiner and Montessori schools. In this study, 20 children participated from each of these…

  18. The Mathematical Intelligence Seen through the Lens of the Montessori Theory of the Human Tendencies.

    Science.gov (United States)

    Baker, Kay M.

    1996-01-01

    Contextualizes the mathematical intelligence as revealed in the human tendencies, as supported by the extended family, and facilitated by choice within a responsive environment. Reviews the function of Montessori materials, including mathematical materials, and emphasizes that the personal intelligences are integral to all activities simply…

  19. Attention

    Science.gov (United States)

    Montessori, Maria

    2016-01-01

    "The Advanced Montessori Method, Volume 1" was published in 1918 in English and is considered a seminal work along with "The Montessori Method." In the foreword to this book, Mario Montessori writes: "...the refulgent figure of the child, Dr. Montessori pointed out, who had found his own path to mental health, who…

  20. Helping Children with Attentional Challenges in a Montessori Classroom: The Role of the Occupational Therapist

    Science.gov (United States)

    Luborsky, Barbara

    2017-01-01

    Barbabra Luborsky links the medical field and Montessori pedagogy to address atypical attention in children through the lens of the occupational therapist. She provides an overview of attention and sensory processing disorders and then informs about particular diagnoses, particularly ADHD and its comorbidity with other diagnoses. Her specific…

  1. Perceptions of High School Seniors' Montessori Experiences and Academic Self-Efficacy Beliefs: A Phenomenological Study

    Science.gov (United States)

    Smith, Molly McHugh

    2010-01-01

    More than twenty-five years after the release of "A Nation at Risk," our federal government continues to explore innovative ways to close the achievement gap. The goal of this phenomenological study was to describe four students' experiences with one school choice option in South Carolina, public Montessori. The purpose of the study was…

  2. The Montessori Experiment in Rhode Island (1913-1940): Tracing Theory to Implementation over 25 Years

    Science.gov (United States)

    Zoll, Susan

    2017-01-01

    This article highlights archived documents pertaining to a 25-year experimental classroom implemented by Clara Craig, then supervisor of training at the Rhode Island Normal School. Craig is notable as she was the only participant in the first International Montessori Training Course in Rome, Italy, in 1913, to gain approval from the Rhode Island…

  3. Opportunities for Inquiry Science in Montessori Classrooms: Learning from a Culture of Interest, Communication, and Explanation

    Science.gov (United States)

    Rinke, Carol R.; Gimbel, Steven J.; Haskell, Sophie

    2013-01-01

    Although classroom inquiry is the primary pedagogy of science education, it has often been difficult to implement within conventional classroom cultures. This study turned to the alternatively structured Montessori learning environment to better understand the ways in which it fosters the essential elements of classroom inquiry, as defined by…

  4. ERASMO PILOTTO AND THE USE OF MONTESSORI METHOD IN THE LITERACY IN PARANÁ

    OpenAIRE

    Campos, Simone Ballmann

    2017-01-01

    The article presents the accomplished use of Montessori literacy by Erasmo Pilotto in the programs for primary education in Paraná. In addition, some of the specificities of Montessor appropriation by him in regard to Early Childhood Education are also presented. Through a historiographic narrative (MAGALHÃES, 2004), composed of advances and remissions in the work with the presented and interpreted materialities, we present a new scene of the History of the Brazilian Education with regard to ...

  5. Making Room for Children's Autonomy: Maria Montessori's Case for Seeing Children's Incapacity for Autonomy as an External Failing

    Science.gov (United States)

    Frierson, Patrick R.

    2016-01-01

    This article draws on Martha Nussbaum's distinction between basic, internal, and external (or combined) capacities to better specify possible locations for children's "incapacity" for autonomy. I then examine Maria Montessori's work on what she calls "normalization", which involves a release of children's capacities for…

  6. How the Montessori Upper Elementary and Adolescent Environment Naturally Integrates Science, Mathematics, Technology, and the Environment

    Science.gov (United States)

    McNamara, John

    2016-01-01

    John McNamara shares his wisdom and humbly credits Camillo Grazzini, Jenny Höglund, and David Kahn for his growth in Montessori. Recognizing more than what he has learned from his mentors, he shares the lessons he has learned from his students themselves. Math, science, history, and language are so integrated in the curriculum that students…

  7. Montessori-based training makes a difference for home health workers & their clients.

    Science.gov (United States)

    Gorzelle, Gregg J; Kaiser, Kathy; Camp, Cameron J

    2003-01-01

    Home care visits can last several hours. Home care workers are often at a loss on how to fill time spent in homes of clients. The challenge is how to use this time in ways that are productive and engaging for both clients and home health workers. The authors trained home health aides to implement Montessori-based activities while interacting with clients who have dementia. The results were amazing. Among other positive results, the authors found a statistically significant increase in the amount of pleasure displayed by clients after health workers received training.

  8. Playing to Learn: An Overview of the Montessori Approach with Pre-School Children with Autism Spectrum Condition

    Science.gov (United States)

    Marks, Laura

    2016-01-01

    This article explores some of the literature concerning the effectiveness of the Montessori educational approach for children with ASC within an English school context. Firstly, there is a discussion, including a short historical review, regarding the ideology of inclusion and how it has impacted upon mainstream education. Also, how this can be…

  9. Evaluation of personalised, one-to-one interaction using Montessori-type activities as a treatment of challenging behaviours in people with dementia: the study protocol of a crossover trial.

    Science.gov (United States)

    van der Ploeg, Eva S; O'Connor, Daniel W

    2010-01-24

    The agitated behaviours that accompany dementia (e.g. pacing, aggression, calling out) are stressful to both nursing home residents and their carers and are difficult to treat. Behaviours stemming from pain, major depression or psychosis benefit from treatment with analgesics, antidepressants or antipsychotics. In other cases, psychotropic medications have limited efficacy but are used very widely. Therefore, increasingly more attention has been paid to nonpharmacological interventions which are associated with fewer risks. The aim of the current study is to test if personalised one-to-one interaction activities based on Montessori principles will reduce the frequency of behavioural symptoms of dementia significantly more than a relevant control condition. We will conduct a controlled trial with randomised cross-over between conditions. Persons with moderate to severe dementia and associated behavioural problems living in aged care facilities will be included in the study. Consented, willing participants will be assigned in random order to Montessori or control blocks for two weeks then switched to the other condition. Montessori activities derive from the principles espoused by Maria Montessori and subsequent educational theorists to promote engagement in learning, namely task breakdown, guided repetition, progression in difficulty from simple to complex, and the careful matching of demands to levels of competence. The control intervention consists of conversation or reading from and looking at pictures in a newspaper to control for non-specific benefits of one-to-one interaction. Presence of target behaviour will be noted as well as level of engagement and type of affect displayed. Secondary measures also include the Cohen-Mansfield Agitation Inventory and information on time and funds spend to prepare the activities. If our results show that use of Montessori activities is effective in treating challenging behaviours in individuals with dementia, it will

  10. Evaluating the Effectiveness of Montessori Reading and Math Instruction for Third Grade African American Students in Urban Elementary Schools

    Science.gov (United States)

    Brown, Katherine Elizabeth

    2016-01-01

    Improving academic achievement for students of color has long been the subject of debate among advocates of education reform (Anyon, 2013; Breitborde & Swiniarski, 2006; Payne, 2008). Some scholars have advocated for the Montessori method as an alternative educational approach to address some chronic problems in public education (Lillard,…

  11. Improving Outcomes for Refugee Children: A Case Study on the Impact of Montessori Education along the Thai-Burma Border

    Science.gov (United States)

    Tobin, Tierney; Boulmier, Prairie; Zhu, Wenyi; Hancock, Paul; Muennig, Peter

    2015-01-01

    There are 25 million displaced children worldwide, and those receiving schooling are often educated in overcrowded classrooms. Montessori is a child-centred educational method that provides an alternative model to traditional educational approaches. In this model, students are able to direct their own learning and develop at their own pace,…

  12. Montessori and Jerome W. Berryman: Work, Play, Religious Education and the Art of Using the Christian Language System

    Science.gov (United States)

    Hyde, Brendan

    2011-01-01

    For more than 30 years, the thinking and writing of Jerome W. Berryman has made a significant and unique contribution to the religious education of children and adults in faith-based contexts. Claiming to be influenced primarily by the work of Maria Montessori, his writings reveal the purpose of religious education to be teaching children the art…

  13. Does Learning the Alphabet in Kindergarten Give Children a Head Start in the First Year of School? A Comparison of Children's Reading Progress in Two First Grade Classes in State and Montessori Schools in Switzerland

    Science.gov (United States)

    Elben, Judy; Nicholson, Tom

    2017-01-01

    The main purpose of this study was to examine whether the age at which children start to learn to read affects their later progress. The study was conducted in Zürich, Switzerland, and compared a first grade class in a local school with two first grade classes in a Montessori school. It was found that although the Montessori children had an…

  14. Actividade e redenção: a criança nova em Maria Montessori

    OpenAIRE

    Alberto Filipe Araújo, Alessandra Avanzini; Joaquim Machado de Araújo

    2011-01-01

    Resumo A ideia de Criança Nova em Maria Montessori (1870-1952) resulta da confluência de duas perspectivas, a da pedagogia que se pretende afirmar como ciência e a do humanismo cristão. Neste artigo, os autores procuram, numa primeira parte, especificar o que vem a ser para a pedagoga italiana a liberdade e a actividade da criança e o papel do adulto, principalmente do educador da criança que se auto-educa e, numa segunda parte, debruçam-se sobre o fundo religioso e humanista da obra montesso...

  15. The Effect of Montessori Method Supported by Social Skills Training Program on Turkish Kindergarten Children's Skills of Understanding Feelings and Social Problem Solving

    Science.gov (United States)

    Kayili, Gökhan; Ari, Ramazan

    2016-01-01

    The current research was conducted with the purpose of analyzing the effect of Montessori method supported by Social Skills Training Program on kindergarten children's skills of understanding feelings and social problem solving. 53 children attending Ihsan Dogramaci Applied Nursery School affiliated to Selcuk University, Faculty of Health Sciences…

  16. Montessori-Based Activities as a Trans-Generational Interface for Persons with Dementia and Preschool Children.

    Science.gov (United States)

    Camp, Cameron J; Lee, Michelle M

    2011-12-12

    Montessori-based activities for persons with dementia have been used to successfully provide opportunities for programming between older adults and preschool children in shared site. intergenerational care programs. Such intergenerational programming allows older adults with dementia to fulfill roles of teacher or mentor to younger children or as collaborative workmates for persons with more advanced dementia while providing children with positive one-on-one interactions with older adults. We review several studies using this approach, describe characteristics of the programs, participants and results obtained and provide recommendations for those interested in extending this line of work.

  17. Montessori-Based Activities as a Trans-Generational Interface for Persons with Dementia and Preschool Children*

    Science.gov (United States)

    Camp, Cameron J.; Lee, Michelle M.

    2012-01-01

    Montessori-based activities for persons with dementia have been used to successfully provide opportunities for programming between older adults and preschool children in shared site. intergenerational care programs. Such intergenerational programming allows older adults with dementia to fulfill roles of teacher or mentor to younger children or as collaborative workmates for persons with more advanced dementia while providing children with positive one-on-one interactions with older adults. We review several studies using this approach, describe characteristics of the programs, participants and results obtained and provide recommendations for those interested in extending this line of work. PMID:22423215

  18. Educación ambiental y participación ciudadana en la Escuela Normal Superior Distrital María Montessori (Environmental education and citizen participation at Escuela Normal Superior Distrital María Montessori

    Directory of Open Access Journals (Sweden)

    Martha Stella Manosalva Corredor

    2015-01-01

    Full Text Available Resumen: Frente al deterioro de las condiciones ambientales, el equipo ambiental de la Escuela Normal Superior Distrital María Montessori de Bogotá y el “Colectivo Acción Ciudadana” convocan a instituciones gubernamentales locales y “ciudadanos habitantes de calle” a un diálogo de saberes para encontrar soluciones concertadas a la problemática ambiental. En el mismo sentido, el proyecto Educación ambiental y participación ciudadana: estrategias de una política de desarrollo sustentable de la ENSDMM trabaja en la propuesta del Plan Institucional de Gestión Ambiental, por lo que realiza una evaluación estratégica ambiental y señala que la educación ambiental y la participación ciudadana son posibles si logran vincular educación y gestión en la definición de los procesos, actividades y actuaciones, con principios de una ética de responsabilidad social, para alcanzar las metas ambientales sustentables.Abstract: With the aim of facing up to the deterioration of the environmental condition, the environmental team of Escuela Normal Superior Distrital María Montessori and “the Collective Citizen Action” convoke the local government institutions and “the citizen street inhabitants” to have a dialogue of knowledge to find concerted solutions for the current environmental problems. In the same sense, the project Environmental Education and Citizen Participation: Strategies for a policy of sustainable development at ENSDMM works on the proposal of the Environmental Management Institutional Plan. It helps to develop a strategic environmental evaluation and points out that the environmental education and citizen participation are possible if education and management are involved in the processes, activities and actions based on principles of social responsibility ethics to achieve the sustainable environmental goals.

  19. Implementing Montessori Methods for Dementia: A Scoping Review.

    Science.gov (United States)

    Hitzig, Sander L; Sheppard, Christine L

    2017-10-01

    A scoping review was conducted to develop an understanding of Montessori-based programing (MBP) approaches used in dementia care and to identify optimal ways to implement these programs across various settings. Six peer-reviewed databases were searched for relevant abstracts by 2 independent reviewers. Included articles and book chapters were those available in English and published by the end of January 2016. Twenty-three articles and 2 book chapters met the inclusion criteria. Four approaches to implementing MBP were identified: (a) staff assisted (n = 14); (b) intergenerational (n = 5); (c) resident assisted (n = 4); and (d) volunteer or family assisted (n = 2). There is a high degree of variability with how MBP was delivered and no clearly established "best practices" or standardized protocol emerged across approaches except for resident-assisted MBP. The findings from this scoping review provide an initial road map on suggestions for implementing MBP across dementia care settings. Irrespective of implementation approach, there are several pragmatic and logistical issues that need to be taken into account for optimal implementation. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Historiando a Montessori: Desde el feminismo y socialismo utópico hacia su compromiso como pionera del holismo

    Directory of Open Access Journals (Sweden)

    Chavarría González, María Celina

    2012-09-01

    Full Text Available Resumen: El presente ensayo indaga acerca de las raíces de la educación montessoriana, pionera de concepciones holistas. Como resultado, se evidencia que únicamente puede ser abordada desde un paradigma de la complejidad y del compromiso con el destino de la humanidad. Solo una comprensión más amplia de su teleología, antropología y epistemología, nos proporcionará la perspectiva que permita integrar estas dimensiones. Con una introducción que parte de la primera costarricense en poner en práctica su filosofía, la preclara Carmen Lyra, se aborda la multi-texualidad, complejidad y trasdisciplinareidad de Montessori, así como sus contingencias y su época, indagación necesaria para sopesar su necesidad hoy.Abstract: A search for Montessori’s roots concludes that an authentic Montessori education, pioneer in holistic conceptions, can only be addressed from a paradigm of complexity, a Transdisciplinary perspective, and an attitude of compromise with the destiny of humanity. Only an all-encompassing understanding of her teleology, anthropology, and epistemology will provide a perspective to integrate these dimensions. In relating Montessori’s circumstances and life-experiences, a parallel is made to the challenges faced by the first practicing Montessorian in Costa Rica, Carmen Lyra, educator, writer, activist, and founding-member of the Costa Rican Communist Party. Montessori’s multi-texuality, contingencies and the quotidien are addressed in an effort to outline her relevance today.

  1. Measurement of transplanted pancreatic volume using computed tomography: reliability by intra- and inter-observer variability

    International Nuclear Information System (INIS)

    Lundqvist, Eva; Segelsjoe, Monica; Magnusson, Anders; Andersson, Anna; Biglarnia, Ali-Reza

    2012-01-01

    Background Unlike other solid organ transplants, pancreas allografts can undergo a substantial decrease in baseline volume after transplantation. This phenomenon has not been well characterized, as there are insufficient data on reliable and reproducible volume assessments. We hypothesized that characterization of pancreatic volume by means of computed tomography (CT) could be a useful method for clinical follow-up in pancreas transplant patients. Purpose To evaluate the feasibility and reliability of pancreatic volume assessment using CT scan in transplanted patients. Material and Methods CT examinations were performed on 21 consecutive patients undergoing pancreas transplantation. Volume measurements were carried out by two observers tracing the pancreatic contours in all slices. The observers performed the measurements twice for each patient. Differences in volume measurement were used to evaluate intra- and inter-observer variability. Results The intra-observer variability for the pancreatic volume measurements of Observers 1 and 2 was found to be in almost perfect agreement, with an intraclass correlation coefficient (ICC) of 0.90 (0.77-0.96) and 0.99 (0.98-1.0), respectively. Regarding inter-observer validity, the ICCs for the first and second measurements were 0.90 (range, 0.77-0.96) and 0.95 (range, 0.85-0.98), respectively. Conclusion CT volumetry is a reliable and reproducible method for measurement of transplanted pancreatic volume

  2. Measurement of transplanted pancreatic volume using computed tomography: reliability by intra- and inter-observer variability

    Energy Technology Data Exchange (ETDEWEB)

    Lundqvist, Eva; Segelsjoe, Monica; Magnusson, Anders [Uppsala Univ., Dept. of Radiology, Oncology and Radiation Science, Section of Radiology, Uppsala (Sweden)], E-mail: eva.lundqvist.8954@student.uu.se; Andersson, Anna; Biglarnia, Ali-Reza [Dept. of Surgical Sciences, Section of Transplantation Surgery, Uppsala Univ. Hospital, Uppsala (Sweden)

    2012-11-15

    Background Unlike other solid organ transplants, pancreas allografts can undergo a substantial decrease in baseline volume after transplantation. This phenomenon has not been well characterized, as there are insufficient data on reliable and reproducible volume assessments. We hypothesized that characterization of pancreatic volume by means of computed tomography (CT) could be a useful method for clinical follow-up in pancreas transplant patients. Purpose To evaluate the feasibility and reliability of pancreatic volume assessment using CT scan in transplanted patients. Material and Methods CT examinations were performed on 21 consecutive patients undergoing pancreas transplantation. Volume measurements were carried out by two observers tracing the pancreatic contours in all slices. The observers performed the measurements twice for each patient. Differences in volume measurement were used to evaluate intra- and inter-observer variability. Results The intra-observer variability for the pancreatic volume measurements of Observers 1 and 2 was found to be in almost perfect agreement, with an intraclass correlation coefficient (ICC) of 0.90 (0.77-0.96) and 0.99 (0.98-1.0), respectively. Regarding inter-observer validity, the ICCs for the first and second measurements were 0.90 (range, 0.77-0.96) and 0.95 (range, 0.85-0.98), respectively. Conclusion CT volumetry is a reliable and reproducible method for measurement of transplanted pancreatic volume.

  3. The effectiveness of spaced retrieval combined with Montessori-based activities in improving the eating ability of residents with dementia.

    Science.gov (United States)

    Wu, Hua Shan; Lin, Li Chan; Wu, Shiao Chi; Lin, Ke Neng; Liu, Hsiu Chih

    2014-08-01

    To explore the long-term effects of standardized and individualized spaced retrieval combined with Montessori-based activities on the eating ability of residents with dementia. Eating difficulty is common in residents with dementia, resulting in low food intake, followed by eating dependence, weight loss and malnutrition. A single-blinded and quasi-experimental design with repeated measures. Ninety residents with dementia from four veterans' homes in Taiwan took part in this study. The intervention consisted of spaced retrieval combined with Montessori-based activities. Twenty-five participants in the standardized group received 24 intervention sessions over 8 weeks. Thirty-eight participants in the individualized group received tailored intervention sessions. The number of intervention sessions was adjusted according to the participant's recall responses in spaced retrieval. Twenty-seven participants in the control group received no treatment. The Chinese version of the Edinburgh Feeding Evaluation in Dementia was used, and eating amounts and body weight were measured pre-test, posttest and at 1-, 3- and 6-month follow-ups. Data were collected between July 2008-February 2010. Repeated measures of all dependent variables for the three groups were analysed by the linear mixed model. The standardized and individualized interventions could significantly decrease the scores for the Chinese version of the Edinburgh Feeding Evaluation in Dementia and increase the eating amount and body weight over time. Trained nurses in institutions can schedule the standardized or individualized intervention in usual activity time to ameliorate eating difficulty and its sequels. © 2014 John Wiley & Sons Ltd.

  4. Il Centro Nascita Montessori. Dal neonato in famiglia al bambino e alla famiglia nel servizio educativo

    Directory of Open Access Journals (Sweden)

    Laura Franceschini

    2010-02-01

    Full Text Available Intervento al Workshop Internazionale “Infanzie e Famiglie in Europa”, del 16 ottobre 2009, presso la Facoltà di Scienze della Formazione, Via Filippo Re, 6 Bologna (Aula Magna. L’intervento illustra i valori fondativi del Centro Nascita Montessori dalle sue origini ai giorni nostri attraverso un percorso che si è allargato nel tempo: dalla focalizzata attenzione e cura al neonato in famiglia o nel brefotrofio fino agli anni ’60 alla cura della crescita del bambino nei servizi educativi e alla cura della relazione con le famiglie dagli anni ‘70 in poi. Tale espansione del campo di interesse e d’indagine operativa ha arricchito il patrimonio di competenze e di conoscenze del C.N.M..

  5. Nisaidie Nif Anye Mwenyewe, Pomogi Mne Eto Sdelat' Samomu: A Comparative Case Study of the Implementation of Montessori Pedagogy in the United Republic of Tanzania and the Russian Federation

    Science.gov (United States)

    Schnepf, Candy A.

    2010-01-01

    The system of education developed by Maria Montessori, noted Italian feminist, anthropologist and physician, is the single largest pedagogy in the world with over 22,000 public, private, parochial, and charter schools on six continents, enduring even as other teaching methods have waxed and waned. Despite its international diffusion and longevity,…

  6. Definition of gross tumor volume in lung cancer: inter-observer variability

    International Nuclear Information System (INIS)

    Van de Steene, Jan; Linthout, Nadine; Mey, Johan de; Vinh-Hung, Vincent; Claassens, Cornelia; Noppen, Marc; Bel, Arjan; Storme, Guy

    2002-01-01

    Background and purpose: To determine the inter-observer variation in gross tumor volume (GTV) definition in lung cancer, and its clinical relevance. Material and methods: Five clinicians involved in lung cancer were asked to define GTV on the planning CT scan of eight patients. Resulting GTVs were compared on the base of geometric volume, dimensions and extensions. Judgement of invasion of lymph node (LN) regions was evaluated using the ATS/LCSG classification of LN. Clinical relevance of the variation was studied through 3D-dosimetry of standard conformal plans: volume of critical organs (heart, lungs, esophagus, spinal cord) irradiated at toxic doses, 95% isodose volumes of GTVs, normal tissue complication probabilities (NTCP) and tumor control probabilities (TCP) were compared for evaluation of observer variability. Results: Before evaluation of observer variability, critical review of planning CT scan led to up- (two cases) and downstaging (one case) of patients as compared to the respective diagnostic scans. The defined GTVs showed an inter-observer variation with a ratio up to more than 7 between maximum and minimum geometric content. The dimensions of the primary tumor had inter-observer ranges of 4.2 (transversal), 7.9 (cranio-caudal) and 5.4 (antero-posterior) cm. Extreme extensions of the GTVs (left, right, cranial, caudal, anterior and posterior) varied with ranges of 2.8-7.3 cm due to inter-observer variation. After common review, only 63% of involved lymph node regions were delineated by the clinicians (i.e. 37% are false negative). Twenty-two percent of drawn in lymph node regions were accepted to be false positive after review. In the conformal plans, inter-observer ranges of irradiated normal tissue volume were on average 12%, with a maximum of 66%. The probability (in the population of all conformal plans) of irradiating at least 95% of the GTV with at least 95% of the nominal treatment dose decreased from 96 to 88% when swapping the matched GTV

  7. HISTORIANDO A MONTESSORI: DESDE EL FEMINISMO Y SOCIALISMO UTÓPICO HACIA SU COMPROMISO COMO PIONERA DEL HOLISMO

    Directory of Open Access Journals (Sweden)

    María Celina Chavarría González

    2012-01-01

    Full Text Available El presente ensayo indaga acerca de las raíces de la educación montessoriana, pionera de concepciones holistas. Como resultado, se evidencia que únicamente puede ser abordada desde un paradigma de la complejidad y del compromiso con el destino de la humanidad. Solo una comprensión más amplia de su teleología, antropología y epistemología, nos proporcionará la perspectiva que permita integrar estas dimensiones. Con una introducción que parte de la primera costarricense en poner en práctica su filosofía, la preclara Carmen Lyra, se aborda la multi-texualidad, complejidad y trasdisciplinareidad de Montessori, así como sus contingencias y su época, indagación necesaria para sopesar su necesidad hoy.

  8. The moderating effect of nutritional status on depressive symptoms in veteran elders with dementia: a spaced retrieval combined with Montessori-based activities.

    Science.gov (United States)

    Wu, Hua-Shan; Lin, Li-Chan

    2013-10-01

    To examine the long-term effects of fixed/individualized spaced retrieval combined with Montessori-based activities on nutritional status and body mass index and nutritional improvement's moderating effect on depressive symptoms for people with dementia during a specific follow-up period. The decrease in food intake, often combined with poor nutrition, may induce depressive symptoms in people with dementia. A single-blind, quasi-experimental study with repeated measures. Twenty-five fixed group participants received spaced retrieval combined with Montessori-based activities over 24 sessions. Thirty-eight individualized group participants received the same intervention with different sessions, which was adjusted according to each participant's learning response. Twenty-seven control group participants just received routine care. The Chinese version of the Mini-Nutritional Assessment and Cornell Scale for Depression in Dementia scores and body mass index were recorded at pre-test, posttest and 1-, 3- and 6-month follow-ups. Data were collected between July 2008-February 2010. The Mini-Nutritional Assessment scores and body mass index of the fixed and individualized groups could be significantly increased over time. Additionally, the Cornell Scale for Depression in Dementia scores could be significantly reduced as a result of the improvement of the Mini-Nutritional Assessment scores arising from the individualized intervention. The depressive symptoms of residents with dementia could be moderated by the individualized intervention through nutritional improvement. Trained clinical nurse specialists can use this individualized intervention for residents with dementia who also have poor nutrition and depressive symptoms. © 2013 Blackwell Publishing Ltd.

  9. Join the Revolution: How Montessori for Aging and Dementia can Change Long-Term Care Culture.

    Science.gov (United States)

    Bourgeois, Michelle S; Brush, Jennifer; Elliot, Gail; Kelly, Anne

    2015-08-01

    Efforts to improve the quality of life of persons with dementia in long-term care through the implementation of various approaches to person-centered care have been underway for the past two decades. Studies have yielded conflicting reports evaluating the evidence for these approaches. The purpose of this article is to outline the findings of several systematic reviews of this literature, highlighting the areas of improvement needs, and to describe a new person-centered care model, DementiAbility Methods: The Montessori Way. This model focuses on the abilities, needs, interests, and strengths of the person and creating worthwhile and meaningful roles, routines, and activities for the person within a supportive physical environment. This is accomplished through gaining the commitment of the facility's leaders, training staff, and monitoring program implementation. The potential for a culture change in long-term care environments is dependent on the development and rigorous evaluation of person-centered care approaches. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  10. Definition of gross tumor volume in lung cancer: inter-observer variability

    NARCIS (Netherlands)

    van de Steene, Jan; Linthout, Nadine; de Mey, Johan; Vinh-Hung, Vincent; Claassens, Cornelia; Noppen, Marc; Bel, Arjan; Storme, Guy

    2002-01-01

    BACKGROUND AND PURPOSE: To determine the inter-observer variation in gross tumor volume (GTV) definition in lung cancer, and its clinical relevance. MATERIALS AND METHODS: Five clinicians involved in lung cancer were asked to define GTV on the planning CT scan of eight patients. Resulting GTVs were

  11. Approaching "The Civic Mission of Schools": Examining Adolescent Civic Engagement in an Alternative Learning Environment

    Science.gov (United States)

    Broome, John P.

    2011-01-01

    The purpose of the study was to examine students' expected and observable civic engagement in a Montessori Erdkinder-based middle school classroom. Research questions included: (a) In what ways is civic engagement addressed in the Montessori Erdkinder-based middle school explicit curriculum? (b) How does the expected civic engagement in the…

  12. Movement Matters: Observing the Benefits of Movement Practice

    Science.gov (United States)

    Fuchs, Melani Alexander

    2015-01-01

    Montessori's first premise is that movement and cognition are closely entwined, and movement can enhance thinking and learning (Lillard, 2005). Children must move, and practice moving, to develop strength, balance, and the stability needed to fully participate in the rigors of daily life. It is imperative for young children's motor…

  13. NO TODO LO QUE SE DICE MONTESSORI LO ES: DECODIFICACIÓN DE ELEMENTOS ESENCIALES EN UN MUNDO GLOBALIZADO (ARE WE BEING MONTESSORIANS? DECODING ESSENTIALS IN A GLOBALIZAD WORLD

    Directory of Open Access Journals (Sweden)

    Chavarría González, María Celina

    2012-05-01

    Full Text Available Resumen: Algunas prácticas montessorianas parecen pasar por alto y ser contradictorias con el sentido original de sus escritos. El presente artículo se pregunta sobre principios esenciales de la educación montessoriana, tomando como perspectiva sus propios escritos, a la luz del paradigma de la Complejidad. Los resultados de la indagación se organizan desde una perspectiva sistémica: (1 descubrimientos sobre la niñez en los contextos propiciados; (2 la relevancia de la educación como diseño cultural; (3 una formación de educadores y educadoras que enfatiza tanto la complejidad como una disposición a la comprensión empática de la niñez, la auto-observación y una perspectiva evolutiva planetaria y de la especie. Se vinculan los conceptos con las corrientes de pensamiento histórico-cultural y desde el paradigma de la complejidad. Como resultados, destacan como actuales los ideales de solidaridad y comunidad de aprendices, el papel de la observación y el respeto por los ciclos de actividad o flujo propuestos por Montessori, así como su convicción de que la evolución de la humanidad, aún incompleta, ha de ser conducida, transdisciplinariamente, en la línea de una evolución cultural consciente, particularmente urgente ante el mundo de las tecnologías de información y comunicación (TICs hoy.Abstract: The present article involves an inquiry into essential conditions for a Montessori education, in three realms: (1 evolutionary characteristics of childhood-in-context; (2 a “scientifically” prepared existential environment, to act interactively towards the learning-education-development of potentialities; (3 a system for the transformation of educators, with emphasis on a disposition towards the empathic apprehension of childhood, a complexity approach, self-observation and a planetary and species evolutionary perspective. In order to relate her concepts with mainstream educational theory, links are made to cultural

  14. Tidal volume and mortality in mechanically ventilated children: a systematic review and meta-analysis of observational studies*.

    Science.gov (United States)

    de Jager, Pauline; Burgerhof, Johannes G M; van Heerde, Marc; Albers, Marcel J I J; Markhorst, Dick G; Kneyber, Martin C J

    2014-12-01

    To determine whether tidal volume is associated with mortality in critically ill, mechanically ventilated children. MEDLINE, EMBASE, and CINAHL databases from inception until July 2013 and bibliographies of included studies without language restrictions. Randomized clinical trials and observational studies reporting mortality in mechanically ventilated PICU patients. Two authors independently selected studies and extracted data on study methodology, quality, and patient outcomes. Meta-analyses were performed using the Mantel-Haenszel random-effects model. Heterogeneity was quantified using I. Study quality was assessed using the Newcastle-Ottawa Score for cohort studies. Out of 142 citations, seven studies met the inclusion criteria, and additional two articles were identified from references of the found articles. One was excluded. These eight studies included 1,756 patients. Mortality rates ranged from 13% to 42%. There was no association between tidal volume and mortality when tidal volume was dichotomized at 7, 8, 10, or 12 mL/kg. Comparing patients ventilated with tidal volume less than 7 mL/kg and greater than 10 mL/kg or greater than 12 mL/kg and tidal volume less than 8 mL/kg and greater than 10 mL/kg or greater than 12 mL/kg also showed no association between tidal volume and mortality. Limiting the analysis to patients with acute lung injury/acute respiratory distress syndrome did not change these results. Heterogeneity was observed in all pooled analyses. A relationship between tidal volume and mortality in mechanically ventilated children could not be identified, irrespective of the severity of disease. The significant heterogeneity observed in the pooled analyses necessitates future studies in well-defined patient populations to understand the effects of tidal volume on patient outcome.

  15. Precise determination of universal finite volume observables in the Gross-Neveu model

    Energy Technology Data Exchange (ETDEWEB)

    Korzec, T.

    2007-01-26

    The Gross-Neveu model is a quantum field theory in two space time dimensions that shares many features with quantum chromo dynamics. In this thesis the continuum model and its discretized versions are reviewed and a finite volume renormalization scheme is introduced and tested. Calculations in the limit of infinitely many fermion flavors as well as perturbative computations are carried out. In extensive Monte-Carlo simulations of the one flavor and the four flavor lattice models with Wilson fermions a set of universal finite volume observables is calculated to a high precision. In the one flavor model which is equivalent to the massless Thirring model the continuum extrapolated Monte-Carlo results are confronted with an exact solution of the model. (orig.)

  16. Precise determination of universal finite volume observables in the Gross-Neveu model

    International Nuclear Information System (INIS)

    Korzec, T.

    2007-01-01

    The Gross-Neveu model is a quantum field theory in two space time dimensions that shares many features with quantum chromo dynamics. In this thesis the continuum model and its discretized versions are reviewed and a finite volume renormalization scheme is introduced and tested. Calculations in the limit of infinitely many fermion flavors as well as perturbative computations are carried out. In extensive Monte-Carlo simulations of the one flavor and the four flavor lattice models with Wilson fermions a set of universal finite volume observables is calculated to a high precision. In the one flavor model which is equivalent to the massless Thirring model the continuum extrapolated Monte-Carlo results are confronted with an exact solution of the model. (orig.)

  17. Resident-Assisted Montessori Programming (RAMP): training persons with dementia to serve as group activity leaders.

    Science.gov (United States)

    Camp, Cameron J; Skrajner, Michael J

    2004-06-01

    The purpose of this study was to determine the effects of an activity implemented by means of Resident-Assisted Montessori Programming (RAMP). Four persons with early-stage dementia were trained to serve as leaders for a small-group activity played by nine persons with more advanced dementia. Assessments of leaders' ability to learn the procedures of leading a group, as well as their satisfaction with this role, were taken, as were measures of players' engagement and affect during standard activities programming and RAMP activities. Leaders demonstrated the potential to fill the role of group activity leader effectively, and they expressed a high level of satisfaction with this role. Players' levels of positive engagement and pleasure during the RAMP activity were higher than during standard group activities. This study suggests that to the extent that procedural learning is available to persons with early-stage dementia, especially when they are assisted with external cueing, these individuals can successfully fill the role of volunteers when working with persons with more advanced dementia. This can provide a meaningful social role for leaders and increase access to high quality activities programming for large numbers of persons with dementia. Copyright 2004 The Gerontological Society of America

  18. Earth observation space programmes, SAFISY activities, strategies of international organisations, legal aspects. Volume 3

    International Nuclear Information System (INIS)

    1992-01-01

    This volume is separated in four sessions. First part is on earth observation space programmes (international earth observation projects and international collaboration, the ERS-1, SPOT and PRIRODA programmes, the first ESA earth observation polar platform and its payload, the future earth observation remote sensing techniques and concepts). The second part is on SAFISY activities (ISY programmes, education and applications, demonstrations and outreach projects). The third part is on programme and strategies of international organisations with respect to earth observation from space. The fourth part is on legal aspects of the use of satellite remote sensing data in Europe. (A.B.). refs., figs., tabs

  19. Noninvasive in vivo plasma volume and hematocrit in humans: observing long-term baseline behavior to establish homeostasis for intravascular volume and composition

    Science.gov (United States)

    Dent, Paul; Deng, Bin; Goodisman, Jerry; Peterson, Charles M.; Narsipur, Sriram; Chaiken, J.

    2016-04-01

    A new device incorporating a new algorithm and measurement process allows simultaneous noninvasive in vivo monitoring of intravascular plasma volume and red blood cell volume. The purely optical technique involves probing fingertip skin with near infrared laser light and collecting the wavelength shifted light, that is, the inelastic emission (IE) which includes the unresolved Raman and fluorescence, and the un-shifted emission, that is, the elastic emission (EE) which includes both the Rayleigh and Mie scattered light. Our excitation and detection geometry is designed so that from these two simultaneous measurements we can calculate two parameters within the single scattering regime using radiation transfer theory, the intravascular plasma volume fraction and the red blood cell volume fraction. Previously calibrated against a gold standard FDA approved device, 2 hour monitoring sessions on three separate occasions over a three week span for a specific, motionless, and mostly sleeping individual produced 3 records containing a total of 5706 paired measurements of hematocrit and plasma volume. The average over the three runs, relative to the initial plasma volume taken as 100%, of the plasma volume±1σ was 97.56+/-0.55 or 0.56%.For the same three runs, the average relative hematocrit (Hct), referenced to an assumed initial value of 28.35 was 29.37+/-0.12 or stable to +/-0.4%.We observe local deterministic circulation effects apparently associated with the pressure applied by the finger probe as well as longer timescale behavior due to normal ebb and flow of internal fluids due to posture changes and tilt table induced gravity gradients.

  20. Caring for people with dementia in residential aged care: successes with a composite person-centered care model featuring Montessori-based activities.

    Science.gov (United States)

    Roberts, Gail; Morley, Catherine; Walters, Wendy; Malta, Sue; Doyle, Colleen

    2015-01-01

    Person-centered models of dementia care commonly merge aspects of existing models with additional influences from published and unpublished evidence and existing government policy. This study reports on the development and evaluation of one such composite model of person-centered dementia care, the ABLE model. The model was based on building the capacity and ability of residents living with dementia, using environmental changes, staff education and organizational and community engagement. Montessori principles were also used. The evaluation of the model employed mixed methods. Significant behavior changes were evident among residents of the dementia care Unit after the model was introduced, as were reductions in anti-psychotic and sedative medication. Staff reported increased knowledge about meeting the needs of people with dementia, and experienced organizational culture change that supported the ABLE model of care. Families were very satisfied with the changes. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Actividade e redenção: a criança nova em Maria Montessori

    Directory of Open Access Journals (Sweden)

    Alberto Filipe Araújo, Alessandra Avanzini

    2011-03-01

    Full Text Available Resumo A ideia de Criança Nova em Maria Montessori (1870-1952 resulta da confluência de duas perspectivas, a da pedagogia que se pretende afirmar como ciência e a do humanismo cristão. Neste artigo, os autores procuram, numa primeira parte, especificar o que vem a ser para a pedagoga italiana a liberdade e a actividade da criança e o papel do adulto, principalmente do educador da criança que se auto-educa e, numa segunda parte, debruçam-se sobre o fundo religioso e humanista da obra montessoriana que consagra a criança como um ser espiritual e de natureza divina. Palavras-chave: actividade; activismo; criança nova; redenção.   Abstract The idea of the New Child in Maria Montesori (1870-1952 is the result of the combination of two perspectives: a pedagogical one, directed at affirming its own scientific status, and one based on Christian Humanism. In this paper the authors try to specify what the Italian pedagogue considered as freedom and activity on the part of the child and the role of the adult, most particularly the role of the educator who also ends up educating himself. At a secondary stage they concentrate on the religious background and the humanism of the Montesorian working method which consecrated the child as a spiritual being who shared the divine nature. Keywords: activity; new child; redemption

  2. Target volume delineation in external beam partial breast irradiation: less inter-observer variation with preoperative- compared to postoperative delineation

    NARCIS (Netherlands)

    Leij, F. van der; Elkhuizen, P.H.M.; Janssen, T.M.; Poortmans, P.M.P.; Sangen, M. van der; Scholten, A.N.; Vliet-Vroegindeweij, C. van; Boersma, L.J.

    2014-01-01

    The challenge of adequate target volume definition in external beam partial breast irradiation (PBI) could be overcome with preoperative irradiation, due to less inter-observer variation. We compared the target volume delineation for external beam PBI on preoperative versus postoperative CT scans of

  3. Retrieving mesospheric water vapour from observations of volume scattering radiances

    Directory of Open Access Journals (Sweden)

    P. Vergados

    2009-02-01

    Full Text Available This study examines the possibility for a theoretical approach in the estimation of water vapour mixing ratios in the vicinity of polar mesospheric clouds (PMC using satellite observations of Volume Scattering Radiances (VSR obtained at the wavelength of 553 nm. The PMC scattering properties perturb the underlying molecular Rayleigh scattered solar radiance of the background atmosphere. As a result, the presence of PMC leads to an enhancement in the observed VSR at the altitude of the layer; the PMC VSRs are superimposed on the exponentially decreasing with height Rayleigh VSR, of the PMC-free atmosphere. The ratio between the observed and the Rayleigh VSR of the background atmosphere is used to simulate the environment in which the cloud layer is formed. In addition, a microphysical model of ice particle formation is employed to predict the PMC VSRs. The initial water vapour profile is perturbed until the modelled VSRs match the observed, at which point the corresponding temperature and water vapour profiles can be considered as a first approximation of those describing the atmosphere at the time of the observations. The role of temperature and water vapour in the cloud formation is examined by a number of sensitivity tests suggesting that the water vapour plays a dominant role in the cloud formation in agreement with experimental results. The estimated water vapour profiles are compared with independent observations to examine the model capability in the context of this study. The results obtained are in a good agreement at the peak of the PMC layer although the radiance rapidly decreases with height below the peak. This simplified scenario indicates that the technique employed can give a first approximation estimate of the water vapour mixing ratio, giving rise to the VSR observed in the presence of PMC.

  4. Volume overload and adverse outcomes in chronic kidney disease: clinical observational and animal studies.

    Science.gov (United States)

    Hung, Szu-Chun; Lai, Yi-Shin; Kuo, Ko-Lin; Tarng, Der-Cherng

    2015-05-05

    Volume overload is frequently encountered and is associated with cardiovascular risk factors in patients with chronic kidney disease (CKD). However, the relationship between volume overload and adverse outcomes in CKD is not fully understood. A prospective cohort of 338 patients with stage 3 to 5 CKD was followed for a median of 2.1 years. The study participants were stratified by the presence or absence of volume overload, defined as an overhydration index assessed by bioimpedance spectroscopy exceeding 7%, the 90th percentile for the healthy population. The primary outcome was the composite of estimated glomerular filtration rate decline ≥50% or end-stage renal disease. The secondary outcome included a composite of morbidity and mortality from cardiovascular causes. Animal models were used to simulate fluid retention observed in human CKD. We found that patients with volume overload were at a higher risk of the primary and secondary end points in the adjusted Cox models. Furthermore, overhydration appears to be more important than hypertension in predicting an elevated risk. In rats subjected to unilateral nephrectomy and a high-salt diet, the extracellular water significantly increased. This fluid retention was associated with an increase in blood pressure, proteinuria, renal inflammation with macrophage infiltration and tumor necrosis factor-α overexpression, glomerular sclerosis, and cardiac fibrosis. Diuretic treatment with indapamide attenuated these changes, suggesting that fluid retention might play a role in the development of adverse outcomes. Volume overload contributes to CKD progression and cardiovascular diseases. Further research is warranted to clarify whether the correction of volume overload would improve outcomes for CKD patients. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  5. Target volume delineation in external beam partial breast irradiation: Less inter-observer variation with preoperative- compared to postoperative delineation

    International Nuclear Information System (INIS)

    Leij, Femke van der; Elkhuizen, Paula H.M.; Janssen, Tomas M.; Poortmans, Philip; Sangen, Maurice van der; Scholten, Astrid N.; Vliet-Vroegindeweij, Corine van; Boersma, Liesbeth J.

    2014-01-01

    The challenge of adequate target volume definition in external beam partial breast irradiation (PBI) could be overcome with preoperative irradiation, due to less inter-observer variation. We compared the target volume delineation for external beam PBI on preoperative versus postoperative CT scans of twenty-four breast cancer patients

  6. For ignoring the moral rights of the photographer Marcus Igno Rudolf Loerbrocks the Dirección Nacional de Derecho de Autor condemned the Colegio Montessori Limitada of Cartagena

    Directory of Open Access Journals (Sweden)

    Tatiana Andrea Triana Uribe

    2017-08-01

    Full Text Available The Colombian Copyrights Office (dnda decided against the Colegio Montessori of Cartagena for infringing the moral rights of disclosure of Marcus Igno Rudolf Loerbroks. This case is important because it is one of the few decisions in which authors moral rights have been protected in Colombia. This ruling reveals the jurisprudential line that the dnda has gradually established for the protection of copyrights in our country, and especially for the moral rights enjoyed by the author of the art work as their owner. This is because, unlike the economic rights, moral rights are perpetual, inalienable and unassignable; as exposed in the case of the artist Gabriel Antonio Calle against the shopping mall San Diego and the case exposed in this review.

  7. Common volume coherent and incoherent scatter radar observations of mid-latitude sporadic E-layers and QP echoes

    Directory of Open Access Journals (Sweden)

    D. L. Hysell

    2004-09-01

    Full Text Available Common-volume observations of sporadic E-layers made on 14-15 June 2002 with the Arecibo incoherent scatter radar and a 30MHz coherent scatter radar imager located on St. Croix are described. Operating in dual-beam mode, the Arecibo radar detected a slowly descending sporadic E-layer accompanied by a series of dense E-region plasma clouds at a time when the coherent scatter radar was detecting quasi-periodic (QP echoes. Using coherent radar imaging, we collocate the sources of the coherent scatter with the plasma clouds observed by Arecibo. In addition to patchy, polarized scattering regions drifting through the radar illuminated volume, which have been observed in previous imaging experiments, the 30MHz radar also detected large-scale electrostatic waves in the E-region over Puerto Rico, with a wavelength of about 30km and a period of about 10min, propagating to the southwest. Both the intensity and the Doppler shifts of the coherent echoes were modulated by the wave.

  8. Cross-correlations in volume space: Differences between buy and sell volumes

    Science.gov (United States)

    Lee, Sun Young; Hwang, Dong Il; Kim, Min Jae; Koh, In Gyu; Kim, Soo Yong

    2011-03-01

    We study the cross-correlations of buy and sell volumes on the Korean stock market in high frequency. We observe that the pulling effects of volumes are as small as that of returns. The properties of the correlations of buy and sell volumes differ. They are explained by the degree of synchronization of stock volumes. Further, the pulling effects on the minimal spanning tree are studied. In minimal spanning trees with directed links, the large pulling effects are clustered at the center, not uniformly distributed. The Epps effect of buy and sell volumes are observed. The reversal of the cross-correlations of buy and sell volumes is also detected.

  9. Resident-Assisted Montessori Programming (RAMP): use of a small group reading activity run by persons with dementia in adult day health care and long-term care settings.

    Science.gov (United States)

    Skrajner, Michael J; Camp, Cameron J

    2007-01-01

    Six persons in the early to middle stages of dementia ("leaders") were trained in Resident-Assisted Montessori Programming (RAMP) to lead a reading activity for 22 persons with more advanced dementia ("participants") in an adult day health center (ADHC) and a special care unit (SCU) in a skilled nursing facility. Researchers assessed the leaders' abilities to learn and follow the procedures of leading a group, as well as their satisfaction with their roles. In addition, participants' engagement and affect were measured, both during standard activities programming and during client-led activities. Results of this study suggest that persons with dementia can indeed successfully lead small group activities, if several important prerequisites are met. Furthermore, the engagement and affect of participants was more positive in client-led activities than in standard activities programming.

  10. Central venous pressure and shock index predict lack of hemodynamic response to volume expansion in septic shock: a prospective, observational study.

    Science.gov (United States)

    Lanspa, Michael J; Brown, Samuel M; Hirshberg, Eliotte L; Jones, Jason P; Grissom, Colin K

    2012-12-01

    Volume expansion is a common therapeutic intervention in septic shock, although patient response to the intervention is difficult to predict. Central venous pressure (CVP) and shock index have been used independently to guide volume expansion, although their use is questionable. We hypothesize that a combination of these measurements will be useful. In a prospective, observational study, patients with early septic shock received 10-mL/kg volume expansion at their treating physician's discretion after brief initial resuscitation in the emergency department. Central venous pressure and shock index were measured before volume expansion interventions. Cardiac index was measured immediately before and after the volume expansion using transthoracic echocardiography. Hemodynamic response was defined as an increase in a cardiac index of 15% or greater. Thirty-four volume expansions were observed in 25 patients. A CVP of 8 mm Hg or greater and a shock index of 1 beat min(-1) mm Hg(-1) or less individually had a good negative predictive value (83% and 88%, respectively). Of 34 volume expansions, the combination of both a high CVP and a low shock index was extremely unlikely to elicit hemodynamic response (negative predictive value, 93%; P = .02). Volume expansion in patients with early septic shock with a CVP of 8 mm Hg or greater and a shock index of 1 beat min(-1) mm Hg(-1) or less is unlikely to lead to an increase in cardiac index. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Grace and Courtesy: A Human Responsibility. AMI/USA Conference (Oak Brook, Illinois, July 23-26, 1998).

    Science.gov (United States)

    American Montessori International of the United States, Inc., Rochester, NY.

    This conference proceedings compile presentations from a 1998 meeting of the American Montessori International of the United States, focusing on the importance of grace and courtesy in children's lives and in Montessori education. The papers presented are: (1) "Grace--The Felicity of Being" (Renilde Montessori); (2) "A Montessori…

  12. Reaping the Benefits of Parent Education

    Science.gov (United States)

    Haakmat, Martha

    2015-01-01

    Martha Haakmat writes in this article that in some ways she understands why parents might have a harder time understanding why Montessori is education at its best, especially as their children progress past preschool. Haakmat goes on to say that the learning path at Montessori schools is more proactive. Montessori schools ask that parents partner…

  13. Supporting Elementary Children in Crisis

    Science.gov (United States)

    Taylor, Liesl Heide

    2017-01-01

    "Just as every child is human, every child, no matter the circumstances, deserves an education that promotes his or her development to the fullest human potential." Using Cornerstone Montessori, a public Montessori school, as a case study, Liesl Taylor sets out to show the importance and impact that the Montessori approach can have on…

  14. Nancy McCormick Rambusch: A Reflection

    Science.gov (United States)

    Povell, Phyllis

    2005-01-01

    Fall of 2005 marks the 12th anniversary of Nancy McCormick Rambusch's death. As the founder of the American Montessori Society and as its first president, Rambusch reintroduced Maria Montessori to America at a time--1960--when education for the young was floundering, and a second look at the Montessori method, which had changed the early childhood…

  15. Effectiveness of Cooperative Learning Instructional Tools With Predict-Observe-Explain Strategy on the Topic of Cuboid and Cube Volume

    Science.gov (United States)

    Nurhuda; Lukito, A.; Masriyah

    2018-01-01

    This study aims to develop instructional tools and implement it to see the effectiveness. The method used in this research referred to Designing Effective Instruction. Experimental research with two-group pretest-posttest design method was conducted. The instructional tools have been developed is cooperative learning model with predict-observe-explain strategy on the topic of cuboid and cube volume which consist of lesson plans, POE tasks, and Tests. Instructional tools were of good quality by criteria of validity, practicality, and effectiveness. These instructional tools was very effective for teaching the volume of cuboid and cube. Cooperative instructional tool with predict-observe-explain (POE) strategy was good of quality because the teacher was easy to implement the steps of learning, students easy to understand the material and students’ learning outcomes completed classically. Learning by using this instructional tool was effective because learning activities were appropriate and students were very active. Students’ learning outcomes were completed classically and better than conventional learning. This study produced a good instructional tool and effectively used in learning. Therefore, these instructional tools can be used as an alternative to teach volume of cuboid and cube topics.

  16. NO TODO LO QUE SE DICE MONTESSORI LO ES: DECODIFICACIÓN DE ELEMENTOS ESENCIALES EN UN MUNDO GLOBALIZADO

    Directory of Open Access Journals (Sweden)

    María Celina Chavarría González

    2012-01-01

    Full Text Available Algunas prácticas montessorianas parecen pasar por alto y ser contradictorias con el sentido original de sus escritos. El presente artículo se pregunta sobre principios esenciales de la educación montessoriana, tomando como perspectiva sus propios escritos, a la luz del paradigma de la Complejidad. Los resultados de la indagación se organizan desde una perspectiva sistémica: (1 descubrimientos sobre la niñez en los contextos propiciados; (2 la relevancia de la educación como diseño cultural; (3 una formación de educadores y educadoras que enfatiza tanto la complejidad como una disposición a la comprensión empática de la niñez, la auto-observación y una perspectiva evolutiva planetaria y de la especie. Se vinculan los conceptos con las corrientes de pensamiento histórico-cultural y desde el paradigma de la complejidad. Como resultados, destacan como actuales los ideales de solidaridad y comunidad de aprendices, el papel de la observación y el respeto por los ciclos de actividad o flujo propuestos por Montessori, así como su convicción de que la evolución de la humanidad, aún incompleta, ha de ser conducida, transdisciplinariamente, en la línea de una evolución cultural consciente, particularmente urgente ante el mundo de las tecnologías de información y comunicación (TICs hoy.

  17. 77 FR 49786 - National Advisory Committee on Institutional Quality and Integrity (NACIQI)

    Science.gov (United States)

    2012-08-17

    ... accreditation of such programs offered via distance education.) 6. Montessori Accreditation Council for Teacher Education (MACTE) (Current Scope: The accreditation of Montessori teacher education institutions and...

  18. Does ultrasonographic volume of the thyroid gland correlate with difficult intubation? An observational study

    Directory of Open Access Journals (Sweden)

    Basak Ceyda Meco

    Full Text Available BACKGROUND AND OBJECTIVES: Preoperative ultrasonographic evaluation of the thyroid gland done by surgeons could let us foresee airway management challenges. The aim of this observational study was to evaluate the effects of thyroid-related parameters assessed preoperatively by surgeons via ultrasonography and chest X-ray on intubation conditions. METHODS: Fifty patients undergoing thyroid surgery were enrolled. Thyromental distance, Mallampati score, neck circumference and range of neck movement were evaluated before the operation. Thyroid volume, signs of invasion or compression and tracheal deviation on chest X-ray were also noted. The intubation conditions were assessed with Cormack and Lehane score and the intubation difficulty scale. Statistical analyses were done with SPSS 15.0 software. RESULTS: The mean thyroid volume of the patients was 26.38 ± 14 mL. The median intubation difficulty scale was 1 (0-2. Thyromental distance (p = 0.011; r = 0.36; 95% CI 0.582-0.088, Mallampati score (p = 0.041; r = 0.29; 95% CI 0.013-0.526, compression or invasion signs (p = 0.041; r = 0.28; 95% CI 0.006-0.521 and tracheal deviation on chest X-ray (p = 0.041; r = 0.52; 95% CI 0.268-0.702 were correlated with intubation difficulty scale. Also patients were classified into two groups related to their intubation difficulty scale (Group I, n = 19: intubation difficulty scale = 0; Group II, n = 31: 1 < intubation difficulty scale ≤ 5 and difficult intubation predictors and thyroid-related parameters were compared. Only Mallampati score was significantly different between groups (p = 0.025. CONCLUSION: The thyroid volume is not associated with difficult intubation. However clinical assessment parameters may predict difficult intubation.

  19. Increased Severe Trauma Patient Volume is Associated With Survival Benefit and Reduced Total Health Care Costs: A Retrospective Observational Study Using a Japanese Nationwide Administrative Database.

    Science.gov (United States)

    Endo, Akira; Shiraishi, Atsushi; Fushimi, Kiyohide; Murata, Kiyoshi; Otomo, Yasuhiro

    2017-06-07

    The aim of this study was to evaluate the associations of severe trauma patient volume with survival benefit and health care costs. The effect of trauma patient volume on survival benefit is inconclusive, and reports on its effects on health care costs are scarce. We conducted a retrospective observational study, including trauma patients who were transferred to government-approved tertiary emergency hospitals, or hospitals with an intensive care unit that provided an equivalent quality of care, using a Japanese nationwide administrative database. We categorized hospitals according to their annual severe trauma patient volumes [1 to 50 (reference), 51 to 100, 101 to 150, 151 to 200, and ≥201]. We evaluated the associations of volume categories with in-hospital survival and total cost per admission using a mixed-effects model adjusting for patient severity and hospital characteristics. A total of 116,329 patients from 559 hospitals were analyzed. Significantly increased in-hospital survival rates were observed in the second, third, fourth, and highest volume categories compared with the reference category [94.2% in the highest volume category vs 88.8% in the reference category, adjusted odds ratio (95% confidence interval, 95% CI) = 1.75 (1.49-2.07)]. Furthermore, significantly lower costs (in US dollars) were observed in the second and fourth categories [mean (standard deviation) for fourth vs reference = $17,800 ($17,378) vs $20,540 ($32,412), adjusted difference (95% CI) = -$2559 (-$3896 to -$1221)]. Hospitals with high volumes of severe trauma patients were significantly associated with a survival benefit and lower total cost per admission.

  20. Making limb and nadir measurements comparable: A common volume study of PMC brightness observed by Odin OSIRIS and AIM CIPS

    Science.gov (United States)

    Benze, Susanne; Gumbel, Jörg; Randall, Cora E.; Karlsson, Bodil; Hultgren, Kristoffer; Lumpe, Jerry D.; Baumgarten, Gerd

    2018-01-01

    Combining limb and nadir satellite observations of Polar Mesospheric Clouds (PMCs) has long been recognized as problematic due to differences in observation geometry, scattering conditions, and retrieval approaches. This study offers a method of comparing PMC brightness observations from the nadir-viewing Aeronomy of Ice in the Mesosphere (AIM) Cloud Imaging and Particle Size (CIPS) instrument and the limb-viewing Odin Optical Spectrograph and InfraRed Imaging System (OSIRIS). OSIRIS and CIPS measurements are made comparable by defining a common volume for overlapping OSIRIS and CIPS observations for two northern hemisphere (NH) PMC seasons: NH08 and NH09. We define a scattering intensity quantity that is suitable for either nadir or limb observations and for different scattering conditions. A known CIPS bias is applied, differences in instrument sensitivity are analyzed and taken into account, and effects of cloud inhomogeneity and common volume definition on the comparison are discussed. Not accounting for instrument sensitivity differences or inhomogeneities in the PMC field, the mean relative difference in cloud brightness (CIPS - OSIRIS) is -102 ± 55%. The differences are largest for coincidences with very inhomogeneous clouds that are dominated by pixels that CIPS reports as non-cloud points. Removing these coincidences, the mean relative difference in cloud brightness reduces to -6 ± 14%. The correlation coefficient between the CIPS and OSIRIS measurements of PMC brightness variations in space and time is remarkably high, at 0.94. Overall, the comparison shows excellent agreement despite different retrieval approaches and observation geometries.

  1. Volume changes and electrostriction in the primary photoreactions of various photosynthetic systems: estimation of dielectric coefficient in bacterial reaction centers and of the observed volume changes with the Drude-Nernst equation.

    Science.gov (United States)

    Mauzerall, David; Hou, Jian-Min; Boichenko, Vladimir A

    2002-01-01

    Photoacoustics (PA) allows the determination of enthalpy and volume changes of photoreactions in photosynthetic reaction centers on the 0.1-10 mus time scale. These include the bacterial centers from Rb. sphaeroides, PS I and PS II centers from Synechocystis and in whole cells. In vitro and in vivo PA data on PS I and PS II revealed that both the volume change (-26 A(3)) and reaction enthalpy (-0.4 eV) in PS I are the same as those in the bacterial centers. However the volume change in PS II is small and the enthalpy far larger, -1 eV. Assigning the volume changes to electrostriction allows a coherent explanation of these observations. One can explain the large volume decrease in the bacterial centers with an effective dielectric coefficient of approximately 4. This is a unique approach to this parameter so important in estimation of protein energetics. The value of the volume contraction for PS I can only be explained if the acceptor is the super- cluster (Fe(4)S(4))(Cys(4)) with charge change from -1 to -2. The small volume change in PS II is explained by sub-mus electron transfer from Y(Z) anion to P(680) cation, in which charge is only moved from the Y(Z) anion to the Q(A) with no charge separation or with rapid proton transfer from oxidized Y(Z) to a polar region and thus very little change in electrostriction. At more acid pH equally rapid proton transfer from a neighboring histidine to a polar region may be caused by the electric field of the P(680) cation.

  2. When high-volume PCI operators in high-volume hospitals move to lower volume hospitals-Do they still maintain high volume and quality of outcomes?

    Science.gov (United States)

    Lu, Tsung-Hsueh; Li, Sheng-Tun; Liang, Fu-Wen; Lee, Jo-Chi; Yin, Wei-Hsian

    2017-10-31

    The aim of this quasi-experimental study was to examine whether high-volume percutaneous coronary intervention (PCI) operators still maintain high volume and quality of outcomes when they moved to lower volume hospitals. Systematic reviews have indicated that high-volume PCI operators and hospitals have higher quality outcomes. However, little is known on whether high PCI volume and high quality outcomes are mainly due to operator characteristics (i.e., skill and experience) and is portable across organizations or whether it is due to hospital characteristics (i.e., equipment, team, and management system) and is less portable. We used Taiwan National Health Insurance claims data 2000-2012 to identify 98 high-volume PCI operators, 10 of whom moved from one hospital to another during the study period. We compared the PCI volume, risk-adjusted mortality ratio, and major adverse cardiovascular event (MACE) ratio before and after moving. Of the 10 high-volume operators who moved, 6 moved from high- to moderate- or low-volume hospitals, with median annual PCI volumes (interquartile range) of 130 (117-165) in prior hospitals and 54 (46-84) in subsequent hospitals (the hospital the operator moved to), and the remaining 4 moved from high to high-volume hospitals, with median annual PCI volumes (interquartile range) of 151 (133-162) in prior hospitals and 193 (178-239) in subsequent hospitals. No significant differences were observed in the risk-adjusted mortality ratios and MACE ratios between high-volume operators and matched controls before and after moving. High-volume operators cannot maintain high volume when they moved from high to moderate or low-volume hospitals; however, the quality of care is maintained. High PCI volume and high-quality outcomes are less portable and more hospital bound. © 2017 Wiley Periodicals, Inc.

  3. Prehospital tidal volume influences hospital tidal volume: A cohort study.

    Science.gov (United States)

    Stoltze, Andrew J; Wong, Terrence S; Harland, Karisa K; Ahmed, Azeemuddin; Fuller, Brian M; Mohr, Nicholas M

    2015-06-01

    The purposes of the study are to describe current practice of ventilation in a modern air medical system and to measure the association of ventilation strategy with subsequent ventilator care and acute respiratory distress syndrome (ARDS). Retrospective observational cohort study of intubated adult patients (n = 235) transported by a university-affiliated air medical transport service to a 711-bed tertiary academic center between July 2011 and May 2013. Low tidal volume ventilation was defined as tidal volumes less than or equal to 8 mL/kg predicted body weight. Multivariable regression was used to measure the association between prehospital tidal volume, hospital ventilation strategy, and ARDS. Most patients (57%) were ventilated solely with bag valve ventilation during transport. Mean tidal volume of mechanically ventilated patients was 8.6 mL/kg predicted body weight (SD, 0.2 mL/kg). Low tidal volume ventilation was used in 13% of patients. Patients receiving low tidal volume ventilation during air medical transport were more likely to receive low tidal volume ventilation in the emergency department (P tidal volume (P = .840). Low tidal volume ventilation was rare during air medical transport. Air transport ventilation strategy influenced subsequent ventilation but was not associated with ARDS. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Reconstructing an Ancient Wonder.

    Science.gov (United States)

    Imhof, Christopher J.

    2001-01-01

    Describes a Montessori class project involving the building of a model of the ancient Briton monument, Stonehenge. Illustrates how the flexibility of the Montessori elementary curriculum encourages children to make their own toys and learn from the process. (JPB)

  5. Volume regulation in epithelia

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Hoffmann, Else Kay

    2016-01-01

    to amphibian skin and mammalian cortical collecting tubule of low and intermediate osmotic permeability. Crosstalk between entrance and exit mechanisms interferes with volume regulation both at aniso-osmotic and iso-osmotic volume perturbations. It has been proposed that cell volume regulation is an intrinsic...... regulation are cloned. The volume-regulated anion channel (VRAC) exhibiting specific electrophysiological characteristics seems exclusive to serve cell volume regulation. This is contrary to K+ channels as well as cotransporters and exchange mechanisms that may serve both transepithelial transport and cell...... volume regulation. In the same cell, these functions may be maintained by different ion pathways that are separately regulated. RVD is often preceded by increase in cytosolic free Ca2+, probably via influx through TRP channels, but Ca2+ release from intracellular stores has also been observed. Cell...

  6. モンテッソーリ・メソッドにおけるA.M.マッケローニの幼児・児童を対象とした音楽指導法 : Music Book: Melodyの検討を中心に

    OpenAIRE

    藤尾, かの子

    2017-01-01

    A.M. Maccheroni developed a music education approach for preschool- and elementary school-aged children using the Montessori Method. To clarify the tenets of Maccheroni’s musical teaching method, we focus on her Music Book. The Music Book consists of 6 volumes; in this study, we start by analyzing Music Book: Melody (Vol. 5), intended for children over 5 years old. As a result of our study, the following becomes clear;1) Music Book: Melody (Vol. 5) aims to increase children’s capacity for mus...

  7. Fifth Lecture

    Science.gov (United States)

    Montessori, Maria

    2013-01-01

    We include the ninth chapter of "Education and Peace" by Maria Montessori (1949) to draw attention to the relationship between peace and sustainability. Nature is an integral part of peace studies. [Reprinted from "Education and Peace," pages 66-70, copyright © 1972 by Montessori-Pierson Publishing Company.

  8. Promoting World Citizenship: A Crucial Area of Study

    Science.gov (United States)

    Hacker, Barbara L.

    2015-01-01

    This article probes the vicissitudes of racism and how the multicultural perspectives of a Montessori preschool environment can prevent prejudices. Barbara Hacker is whole-heartedly committed to human unity transcending color differences. Racism is incompatible with a Montessori classroom that shares different holidays and cultures, builds social…

  9. Quantitative assessment of inter-observer variability in target volume delineation on stereotactic radiotherapy treatment for pituitary adenoma and meningioma near optic tract

    International Nuclear Information System (INIS)

    Yamazaki, Hideya; Ogita, Mikio; Yamashita, Koichi; Kotsuma, Tadayuki; Shiomi, Hiroya; Tsubokura, Takuji; Kodani, Naohiro; Nishimura, Takuya; Aibe, Norihiro; Udono, Hiroki; Nishikata, Manabu; Baba, Yoshimi

    2011-01-01

    To assess inter-observer variability in delineating target volume and organs at risk in benign tumor adjacent to optic tract as a quality assurance exercise. We quantitatively analyzed 21 plans made by 11 clinicians in seven CyberKnife centers. The clinicians were provided with a raw data set (pituitary adenoma and meningioma) including clinical information, and were asked to delineate the lesions and create a treatment plan. Their contouring and plans (10 adenoma and 11 meningioma plans), were then compared. In addition, we estimated the influence of differences in contouring by superimposing the respective contours onto a default plan. The median planning target volume (PTV) and the ratio of the largest to the smallest contoured volume were 9.22 cm 3 (range, 7.17 - 14.3 cm 3 ) and 1.99 for pituitary adenoma, and 6.86 cm 3 (range 6.05 - 14.6 cm 3 ) and 2.41 for meningioma. PTV volume was 10.1 ± 1.74 cm 3 for group 1 with a margin of 1 -2 mm around the CTV (n = 3) and 9.28 ± 1.8 cm 3 (p = 0.51) for group 2 with no margin (n = 7) in pituitary adenoma. In meningioma, group 1 showed larger PTV volume (10.1 ± 3.26 cm 3 ) than group 2 (6.91 ± 0.7 cm 3 , p = 0.03). All submitted plan keep the irradiated dose to optic tract within the range of 50 Gy (equivalent total doses in 2 Gy fractionation). However, contours superimposed onto the dose distribution of the default plan indicated that an excessive dose 23.64 Gy (up to 268% of the default plan) in pituitary adenoma and 24.84 Gy (131% of the default plan) in meningioma to the optic nerve in the contours from different contouring. Quality assurance revealed inter-observer variability in contour delineation and their influences on planning for pituitary adenoma and meningioma near optic tract

  10. Assessment of liver volume with spiral computerized tomography scanning: predicting liver volume by age and height

    OpenAIRE

    Madhu Sharma; Abhishek Singh; Shewtank Goel; Setu Satani; Kavita Mudgil

    2016-01-01

    Background: Estimation of liver size has critical clinical implication. Precise knowledge of liver dimensions and volume is prerequisite for clinical assessment of liver disorders. Liver span as measured by palpation and USG is prone to inter-observer variability and poor repeatability. The aim was to assess the normal liver volume of healthy adults using spiral computed tomography scans and to observe its relationship with various body indices. Methods: In this prospective study, all the...

  11. Correlation of ultrasound estimated placental volume and umbilical cord blood volume in term pregnancy.

    Science.gov (United States)

    Pannopnut, Papinwit; Kitporntheranunt, Maethaphan; Paritakul, Panwara; Kongsomboon, Kittipong

    2015-01-01

    To investigate the correlation between ultrasound measured placental volume and collected umbilical cord blood (UCB) volume in term pregnancy. An observational cross-sectional study of term singleton pregnant women in the labor ward at Maha Chakri Sirindhorn Medical Center was conducted. Placental thickness, height, and width were measured using two-dimensional (2D) ultrasound and calculated for placental volume using the volumetric mathematic model. After the delivery of the baby, UCB was collected and measured for its volume immediately. Then, birth weight, placental weight, and the actual placental volume were analyzed. The Pearson's correlation was used to determine the correlation between each two variables. A total of 35 pregnant women were eligible for the study. The mean and standard deviation of estimated placental volume and actual placental volume were 534±180 mL and 575±118 mL, respectively. The median UCB volume was 140 mL (range 98-220 mL). The UCB volume did not have a statistically significant correlation with the estimated placental volume (correlation coefficient 0.15; p=0.37). However, the UCB volume was significantly correlated with the actual placental volume (correlation coefficient 0.62; pcorrelation coefficient 0.38; p=0.02). The estimated placental volume by 2D ultrasound was not significantly correlated with the UCB volume. Further studies to establish the correlation between the UCB volume and the estimated placental volume using other types of placental imaging may be needed.

  12. Insignificant change in Antarctic snowmelt volume since 1979

    NARCIS (Netherlands)

    Kuipers Munneke, P.; Picard, G.; van den Broeke, M.R.; Lenaerts, J.T.M.; van Meijgaard, E.

    2012-01-01

    Surface snowmelt is widespread in coastal Antarctica. Satellite-based microwave sensors have been observing melt area and duration for over three decades. However, these observations do not reveal the total volume of meltwater produced on the ice sheet. Here we present an Antarctic melt volume

  13. TU-A-12A-06: Intra-Observer Variability in Delineation of Target Volumes in Breast Radiotherapy and Its Effect On Accuracy of Deformation Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Juneja, P; Harris, E [The Institute of Cancer Research, London (United Kingdom); Royal Marsden NHS Foundation Trust, Sutton (United Kingdom); Bonora, M [University of Milan, Milan (Italy); Evans, P [University of Surrey, Guildford (United Kingdom)

    2014-06-15

    Purpose: In breast radiotherapy, the target volume may change during treatment and need adaptation of the treatment plan. This is possible for both tumour bed (TB) and whole breast (WB) target volumes. Delineation of the target (to detect changes) is also subject to uncertainty due to intra- and inter-observer variability. This work measured the uncertainty, due to intraobserver variability, in the quantification of tissue deformation. Methods: Datasets consisting of paired prone and supine CT scans of three patients were used. Significant deformation in target volumes is expected between prone and supine patient positions. The selected cases had 1) no seroma, 2) some seroma, and 3) large seroma. The TB and WB were outlined on each dataset three times by one clinician. Delineation variability was defined as the standard deviations of the distances between observer outlines. For each target volume and each case, tissue deformation between prone and supine delineations was quantified using the Dice similarity coefficient (DSC) and the average surface distance (ASD). The uncertainty in the tissue deformation (due to delineation variability) was quantified by measuring the ranges of DSC and ASD using all combinations of pairs of outlines (9 pairs). Results: For the TB, the range of delineation variability was 0.44-1.16 mm. The deformation, DSC and ASD, (and uncertainty in measurement) of the TB between prone and supine position of the cases were: 1) 0.21 (0.17-0.28) and 12.4 mm (11.8-13 mm); 2) 0.54 (0.51-0.57) and 3.3 mm (3.1-3.5 mm); 3) 0.62 (0.61-0.64) and 4.9 mm (4.6-5.2 mm). WB deformation measurements were subject to less uncertainty due to delineation variability than TB deformation measurements. Conclusion: For the first time, the uncertainty, due to observer variability, in the measurement of the deformation of breast target volumes was investigated. Deformations in these ranges would be difficult to detect. This work was supported in part by Cancer Research

  14. Three-dimensional reconstruction volume: a novel method for volume measurement in kidney cancer.

    Science.gov (United States)

    Durso, Timothy A; Carnell, Jonathan; Turk, Thomas T; Gupta, Gopal N

    2014-06-01

    The role of volumetric estimation is becoming increasingly important in the staging, management, and prognostication of benign and cancerous conditions of the kidney. We evaluated the use of three-dimensional reconstruction volume (3DV) in determining renal parenchymal volumes (RPV) and renal tumor volumes (RTV). We compared 3DV with the currently available methods of volume assessment and determined its interuser reliability. RPV and RTV were assessed in 28 patients who underwent robot-assisted laparoscopic partial nephrectomy for kidney cancer. Patients with a preoperative creatinine level of kidney pre- and postsurgery overestimated 3D reconstruction volumes by 15% to 102% and 12% to 101%, respectively. In addition, volumes obtained from 3DV displayed high interuser reliability regardless of experience. 3DV provides a highly reliable way of assessing kidney volumes. Given that 3DV takes into account visible anatomy, the differences observed using previously published methods can be attributed to the failure of geometry to accurately approximate kidney or tumor shape. 3DV provides a more accurate, reproducible, and clinically useful tool for urologists looking to improve patient care using analysis related to volume.

  15. The Maiden Voyage of a Kinematics Robot

    Science.gov (United States)

    Greenwolfe, Matthew L.

    2015-01-01

    In a Montessori preschool classroom, students work independently on tasks that absorb their attention in part because the apparatus are carefully designed to make mistakes directly observable and limit exploration to one aspect or dimension. Control of error inheres in the apparatus itself, so that teacher intervention can be minimal. Inspired by…

  16. Multiracial Family Seeking Multiracial School: One Parent's Perspective

    Science.gov (United States)

    Shaver, Christina

    2006-01-01

    This author observed that many Montessori schools have made efforts to include diversity in their programs. She toured schools in Chicago and found them oozing with multicultural awareness--from the library books on the shelves to the marketing materials they provided to the classroom celebrations of a variety of holidays. However, she observed…

  17. Movement and Character. Lecture, London, 1946

    Science.gov (United States)

    Montesorri, Maria

    2013-01-01

    Dr. Montessori's words from the 1946 London Lectures describe principles of intelligence and character, the work of the hand, and movement with a purpose as being integral to self-construction. The perfection of movement is spiritual, says Dr. Montessori. Repetition of practical life exercises are exercises in movement with the dignity of human…

  18. The Need for Precision

    Science.gov (United States)

    Weinberg, David R.

    2012-01-01

    People have become accustomed to the imprecision of language, though imprecise language has a subtle way of misguiding thoughts and actions. In this article, the author argues that the term "teacher" in reference to the Montessori practitioner is a distortion of everything Maria Montessori tried to undo about traditional education. In dealing with…

  19. The House of Children. Lecture, Kodaikanal, 1944

    Science.gov (United States)

    Montessori, Maria

    2013-01-01

    This article vividly describes the indoor and outdoor components of what Montessori calls Home Sweet Home. Her vision of a domestic Children's House contains many facets: rooms of varied space, beautiful flooring, gardens that educate and evoke collaboration, and places for year-round exercise. This is a definitive yet rare Montessori article that…

  20. The Egg Man and the Empress

    Science.gov (United States)

    Smith, Dennis R.

    2005-01-01

    In this article, the author compares the legacies of two remarkable educators--John Dewey and Maria Montessori. These include changes in education now so commonplace that is accepted as traditional. Both Montessori and Dewey lived long enough to see their ideas receive worldwide recognition and acceptance, along with a share of misunderstanding…

  1. SU-E-J-266: Cone Beam Computed Tomography (CBCT) Inter-Scan and Inter-Observer Tumor Volume Variability Assessment in Patients Treated with Stereotactic Body Radiation Therapy (SBRT) for Early Stage Non-Small Cell Lung Cancer (NSCLC)

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Y; Aileen, C; Kozono, D; Killoran, J; Wagar, M; Lee, S; Hacker, F; Aerts, H; Lewis, J; Mak, R [Brigham and Women’s Hospital, Boston, MA (United States)

    2015-06-15

    Purpose: Quantification of volume changes on CBCT during SBRT for NSCLC may provide a useful radiological marker for radiation response and adaptive treatment planning, but the reproducibility of CBCT volume delineation is a concern. This study is to quantify inter-scan/inter-observer variability in tumor volume delineation on CBCT. Methods: Twenty earlystage (stage I and II) NSCLC patients were included in this analysis. All patients were treated with SBRT with a median dose of 54 Gy in 3 to 5 fractions. Two physicians independently manually contoured the primary gross tumor volume on CBCTs taken immediately before SBRT treatment (Pre) and after the same SBRT treatment (Post). Absolute volume differences (AVD) were calculated between the Pre and Post CBCTs for a given treatment to quantify inter-scan variability, and then between the two observers for a given CBCT to quantify inter-observer variability. AVD was also normalized with respect to average volume to obtain relative volume differences (RVD). Bland-Altman approach was used to evaluate variability. All statistics were calculated with SAS version 9.4. Results: The 95% limit of agreement (mean ± 2SD) on AVD and RVD measurements between Pre and Post scans were −0.32cc to 0.32cc and −0.5% to 0.5% versus −1.9 cc to 1.8 cc and −15.9% to 15.3% for the two observers respectively. The 95% limit of agreement of AVD and RVD between the two observers were −3.3 cc to 2.3 cc and −42.4% to 28.2% respectively. The greatest variability in inter-scan RVD was observed with very small tumors (< 5 cc). Conclusion: Inter-scan variability in RVD is greatest with small tumors. Inter-observer variability was larger than inter-scan variability. The 95% limit of agreement for inter-observer and inter-scan variability (∼15–30%) helps define a threshold for clinically meaningful change in tumor volume to assess SBRT response, with larger thresholds needed for very small tumors. Part of the work was funded by a Kaye

  2. SU-E-J-266: Cone Beam Computed Tomography (CBCT) Inter-Scan and Inter-Observer Tumor Volume Variability Assessment in Patients Treated with Stereotactic Body Radiation Therapy (SBRT) for Early Stage Non-Small Cell Lung Cancer (NSCLC)

    International Nuclear Information System (INIS)

    Hou, Y; Aileen, C; Kozono, D; Killoran, J; Wagar, M; Lee, S; Hacker, F; Aerts, H; Lewis, J; Mak, R

    2015-01-01

    Purpose: Quantification of volume changes on CBCT during SBRT for NSCLC may provide a useful radiological marker for radiation response and adaptive treatment planning, but the reproducibility of CBCT volume delineation is a concern. This study is to quantify inter-scan/inter-observer variability in tumor volume delineation on CBCT. Methods: Twenty earlystage (stage I and II) NSCLC patients were included in this analysis. All patients were treated with SBRT with a median dose of 54 Gy in 3 to 5 fractions. Two physicians independently manually contoured the primary gross tumor volume on CBCTs taken immediately before SBRT treatment (Pre) and after the same SBRT treatment (Post). Absolute volume differences (AVD) were calculated between the Pre and Post CBCTs for a given treatment to quantify inter-scan variability, and then between the two observers for a given CBCT to quantify inter-observer variability. AVD was also normalized with respect to average volume to obtain relative volume differences (RVD). Bland-Altman approach was used to evaluate variability. All statistics were calculated with SAS version 9.4. Results: The 95% limit of agreement (mean ± 2SD) on AVD and RVD measurements between Pre and Post scans were −0.32cc to 0.32cc and −0.5% to 0.5% versus −1.9 cc to 1.8 cc and −15.9% to 15.3% for the two observers respectively. The 95% limit of agreement of AVD and RVD between the two observers were −3.3 cc to 2.3 cc and −42.4% to 28.2% respectively. The greatest variability in inter-scan RVD was observed with very small tumors (< 5 cc). Conclusion: Inter-scan variability in RVD is greatest with small tumors. Inter-observer variability was larger than inter-scan variability. The 95% limit of agreement for inter-observer and inter-scan variability (∼15–30%) helps define a threshold for clinically meaningful change in tumor volume to assess SBRT response, with larger thresholds needed for very small tumors. Part of the work was funded by a Kaye

  3. Math Tracks: What Pace in Math Is Best for the Middle School Child?

    Science.gov (United States)

    Morrison, Michelle

    2011-01-01

    Mathematics is a critical part of academic preparation of the middle school child, or, as Dr. Maria Montessori would refer to them, children in the third plane of development. Montessori educators are sincere in their endeavors not only to prepare young students for further studies of math and the application of math in their world and careers,…

  4. Lecture 4: April 11, 1927

    Science.gov (United States)

    Montessori, Maria

    2016-01-01

    Using examples from the animal world, Montessori speaks of the natural laws of life and the phases of childhood that are different than that of the adult. The child develops independently of the adult. Montessori says, "The child is the period when man is created," and "The child is a worker." Through work, the child can arrive…

  5. Order, Organization, and Beauty in the Classroom: A Prerequisite, Not an Option

    Science.gov (United States)

    Haskins, Cathleen

    2012-01-01

    Montessori education, at its best, is a combination of art and science, an exquisite balance of subjectivity and objectivity. When done well, a Montessori environment resembles a carefully crafted piece of art, a skillfully constructed laboratory for the study of life. The work of creating such a masterpiece is a labor of love and a commitment of…

  6. The Children's House

    Science.gov (United States)

    Peller, Lili E.

    2013-01-01

    Lili Peller's "The Children's House" essay begins where Maria Montessori left off in her description of space articulations. Peller does not name Montessori specifically as she always had a desire to become independent in her own right as a neo-Freudian child analyst. But the Haus Der Kinder founded in summer of 1922 suggests a total…

  7. Grace and Courtesy and Beyond

    Science.gov (United States)

    Schaefer, Pat

    2015-01-01

    Taking up the cause of grace and courtesy across the planes of education, Pat Schaefer tells of the grace and courtesy of successive planes within a school culture and gives a glimpse of how the Montessori vision of a new society can look. Grace and courtesy go well beyond the practice of manners and into the topic of deep observation and…

  8. Interobserver variations of target volume delineation and its impact on irradiated volume in accelerated partial breast irradiation with intraoperative interstitial breast implant

    Directory of Open Access Journals (Sweden)

    Ritu Raj Upreti

    2017-02-01

    Full Text Available Purpose: To investigate the interobserver variations in delineation of lumpectomy cavity (LC and clinical target volume (CTV, and its impact on irradiated volume in accelerated partial breast irradiation using intraoperative multicatheter brachytherapy. Material and methods : Delineation of LC and CTV was done by five radiation oncologists on planning computed tomography (CT scans of 20 patients with intraoperative interstitial breast implant. Cavity visualization index (CVI, four-point index ranging from (0 = poor to (3 = excellent was created and assigned by observers for each patient. In total, 200 contours for all observers and 100 treatment plans were evaluated. Spatial concordance (conformity index, CI common , and CIgen, average shift in the center of mass (COM, and ratio of maximum and minimum volumes (V max /V min of LC and CTV were quantified among all observers and statistically analyzed. Variation in active dwell positions (0.5 cm step for each catheter, total reference air kerma (TRAK, volume enclosed by prescription isodose (V100% among observers and its spatial concordance were analyzed. Results : The mean ± SD CI common of LC and CTV was 0.54 ± 0.09, and 0.58 ± 0.08, respectively. Conformity index tends to increase, shift in COM and V max /V min decrease significantly (p < 0.05, as CVI increased. Out of total 309 catheters, 29.8% catheters had no change, 29.8% and 17.5% catheters had variations of 1 and 2 dwell positions (0.5 cm and 1 cm, respectively. 9.3% catheters shown variations ≥ 10 dwell positions (5 cm. The mean ± SD CI common of V100% was 0.75 ± 0.11. The mean observed V max /V min of prescription isodose and TRAK was 1.18 (range, 1.03 to 1.56 and 1.11 (range, 1.03 to 1.35, respectively. Conclusions : Interobserver variability in delineation of target volume was found to be significantly related to CVI. Smaller variability was observed with excellent visualization of LC. Interobserver variations showed dosimetric

  9. Observations of Recent Arctic Sea Ice Volume Loss and Its Impact on Ocean-Atmosphere Energy Exchange and Ice Production

    Science.gov (United States)

    Kurtz, N. T.; Markus, T.; Farrell, S. L.; Worthen, D. L.; Boisvert, L. N.

    2011-01-01

    Using recently developed techniques we estimate snow and sea ice thickness distributions for the Arctic basin through the combination of freeboard data from the Ice, Cloud, and land Elevation Satellite (ICESat) and a snow depth model. These data are used with meteorological data and a thermodynamic sea ice model to calculate ocean-atmosphere heat exchange and ice volume production during the 2003-2008 fall and winter seasons. The calculated heat fluxes and ice growth rates are in agreement with previous observations over multiyear ice. In this study, we calculate heat fluxes and ice growth rates for the full distribution of ice thicknesses covering the Arctic basin and determine the impact of ice thickness change on the calculated values. Thinning of the sea ice is observed which greatly increases the 2005-2007 fall period ocean-atmosphere heat fluxes compared to those observed in 2003. Although there was also a decline in sea ice thickness for the winter periods, the winter time heat flux was found to be less impacted by the observed changes in ice thickness. A large increase in the net Arctic ocean-atmosphere heat output is also observed in the fall periods due to changes in the areal coverage of sea ice. The anomalously low sea ice coverage in 2007 led to a net ocean-atmosphere heat output approximately 3 times greater than was observed in previous years and suggests that sea ice losses are now playing a role in increasing surface air temperatures in the Arctic.

  10. Small-Volume Injections: Evaluation of Volume Administration Deviation From Intended Injection Volumes.

    Science.gov (United States)

    Muffly, Matthew K; Chen, Michael I; Claure, Rebecca E; Drover, David R; Efron, Bradley; Fitch, William L; Hammer, Gregory B

    2017-10-01

    In the perioperative period, anesthesiologists and postanesthesia care unit (PACU) nurses routinely prepare and administer small-volume IV injections, yet the accuracy of delivered medication volumes in this setting has not been described. In this ex vivo study, we sought to characterize the degree to which small-volume injections (≤0.5 mL) deviated from the intended injection volumes among a group of pediatric anesthesiologists and pediatric postanesthesia care unit (PACU) nurses. We hypothesized that as the intended injection volumes decreased, the deviation from those intended injection volumes would increase. Ten attending pediatric anesthesiologists and 10 pediatric PACU nurses each performed a series of 10 injections into a simulated patient IV setup. Practitioners used separate 1-mL tuberculin syringes with removable 18-gauge needles (Becton-Dickinson & Company, Franklin Lakes, NJ) to aspirate 5 different volumes (0.025, 0.05, 0.1, 0.25, and 0.5 mL) of 0.25 mM Lucifer Yellow (LY) fluorescent dye constituted in saline (Sigma Aldrich, St. Louis, MO) from a rubber-stoppered vial. Each participant then injected the specified volume of LY fluorescent dye via a 3-way stopcock into IV tubing with free-flowing 0.9% sodium chloride (10 mL/min). The injected volume of LY fluorescent dye and 0.9% sodium chloride then drained into a collection vial for laboratory analysis. Microplate fluorescence wavelength detection (Infinite M1000; Tecan, Mannedorf, Switzerland) was used to measure the fluorescence of the collected fluid. Administered injection volumes were calculated based on the fluorescence of the collected fluid using a calibration curve of known LY volumes and associated fluorescence.To determine whether deviation of the administered volumes from the intended injection volumes increased at lower injection volumes, we compared the proportional injection volume error (loge [administered volume/intended volume]) for each of the 5 injection volumes using a linear

  11. Observer variation in target volume delineation of lung cancer related to radiation oncologist-computer interaction: A 'Big Brother' evaluation

    International Nuclear Information System (INIS)

    Steenbakkers, Roel J.H.M.; Duppen, Joop C.; Fitton, Isabelle; Deurloo, Kirsten E.I.; Zijp, Lambert; Uitterhoeve, Apollonia L.J.; Rodrigus, Patrick T.R.; Kramer, Gijsbert W.P.; Bussink, Johan; Jaeger, Katrien De; Belderbos, Jose S.A.; Hart, Augustinus A.M.; Nowak, Peter J.C.M.; Herk, Marcel van; Rasch, Coen R.N.

    2005-01-01

    Background and purpose: To evaluate the process of target volume delineation in lung cancer for optimization of imaging, delineation protocol and delineation software. Patients and methods: Eleven radiation oncologists (observers) from five different institutions delineated the Gross Tumor Volume (GTV) including positive lymph nodes of 22 lung cancer patients (stages I-IIIB) on CT only. All radiation oncologist-computer interactions were recorded with a tool called 'Big Brother'. For each radiation oncologist and patient the following issues were analyzed: delineation time, number of delineated points and corrections, zoom levels, level and window (L/W) settings, CT slice changes, use of side windows (coronal and sagittal) and software button use. Results: The mean delineation time per GTV was 16 min (SD 10 min). The mean delineation time for lymph node positive patients was on average 3 min larger (P=0.02) than for lymph node negative patients. Many corrections (55%) were due to L/W change (e.g. delineating in mediastinum L/W and then correcting in lung L/W). For the lymph node region, a relatively large number of corrections was found (3.7 corr/cm 2 ), indicating that it was difficult to delineate lymph nodes. For the tumor-atelectasis region, a relative small number of corrections was found (1.0 corr/cm 2 ), indicating that including or excluding atelectasis into the GTV was a clinical decision. Inappropriate use of L/W settings was frequently found (e.g. 46% of all delineated points in the tumor-lung region were delineated in mediastinum L/W settings). Despite a large observer variation in cranial and caudal direction of 0.72 cm (1 SD), the coronal and sagittal side windows were not used in 45 and 60% of the cases, respectively. For the more difficult cases, observer variation was smaller when the coronal and sagittal side windows were used. Conclusions: With the 'Big Brother' tool a method was developed to trace the delineation process. The differences between

  12. The estimation of bone cyst volume using the Cavalieri principle on computed tomography images.

    Science.gov (United States)

    Say, Ferhat; Gölpınar, Murat; Kılınç, Cem Yalın; Şahin, Bünyamin

    2018-01-01

    To evaluate the volume of bone cyst using the planimetry method of the Cavalieri principle. A retrospective analysis was carried out on data from 25 computed tomography (CT) images of patients with bone cyst. The volume of the cysts was calculated by two independent observers using the planimetry method. The procedures were repeated 1 month later by each observer. The overall mean volume of the bone cyst was 29.25 ± 25.86 cm 3 . The mean bone cyst volumes calculated by the first observer for the first and second sessions were 29.18 ± 26.14 and 29.27 ± 26.19 cm 3 , respectively. The mean bone cyst volumes calculated by the second observer for the first and second sessions were 29.32 ± 26.36 and 29.23 ± 26.36 cm 3 , respectively. Statistical analysis showed no difference and high agreement between the first and second measurements of both observers. The Bland-Altman plots showed strong intraobserver and interobserver concordance in the measurement of the bone cyst volume. The mean total time necessary to obtain the cyst volume by the two observers was 5.27 ± 2.30 min. The bone cyst of the patients can be objectively evaluated using the planimetry method of the Cavalieri principle on CT. This method showed high interobserver and intraobserver agreement. This volume measurement can be used to evaluate cyst remodeling, including complete healing and cyst recurrence.

  13. [Target volume margins for lung cancer: internal target volume/clinical target volume].

    Science.gov (United States)

    Jouin, A; Pourel, N

    2013-10-01

    The aim of this study was to carry out a review of margins that should be used for the delineation of target volumes in lung cancer, with a focus on margins from gross tumour volume (GTV) to clinical target volume (CTV) and internal target volume (ITV) delineation. Our review was based on a PubMed literature search with, as a cornerstone, the 2010 European Organisation for Research and Treatment of Cancer (EORTC) recommandations by De Ruysscher et al. The keywords used for the search were: radiotherapy, lung cancer, clinical target volume, internal target volume. The relevant information was categorized under the following headings: gross tumour volume definition (GTV), CTV-GTV margin (first tumoural CTV then nodal CTV definition), in field versus elective nodal irradiation, metabolic imaging role through the input of the PET scanner for tumour target volume and limitations of PET-CT imaging for nodal target volume definition, postoperative radiotherapy target volume definition, delineation of target volumes after induction chemotherapy; then the internal target volume is specified as well as tumoural mobility for lung cancer and respiratory gating techniques. Finally, a chapter is dedicated to planning target volume definition and another to small cell lung cancer. For each heading, the most relevant and recent clinical trials and publications are mentioned. Copyright © 2013. Published by Elsevier SAS.

  14. Volume measurement variability in three-dimensional high-frequency ultrasound images of murine liver metastases

    International Nuclear Information System (INIS)

    Wirtzfeld, L A; Graham, K C; Groom, A C; MacDonald, I C; Chambers, A F; Fenster, A; Lacefield, J C

    2006-01-01

    The identification and quantification of tumour volume measurement variability is imperative for proper study design of longitudinal non-invasive imaging of pre-clinical mouse models of cancer. Measurement variability will dictate the minimum detectable volume change, which in turn influences the scheduling of imaging sessions and the interpretation of observed changes in tumour volume. In this paper, variability is quantified for tumour volume measurements from 3D high-frequency ultrasound images of murine liver metastases. Experimental B16F1 liver metastases were analysed in different size ranges including less than 1 mm 3 , 1-4 mm 3 , 4-8 mm 3 and 8-70 mm 3 . The intra- and inter-observer repeatability was high over a large range of tumour volumes, but the coefficients of variation (COV) varied over the volume ranges. The minimum and maximum intra-observer COV were 4% and 14% for the 1-4 mm 3 and 3 tumours, respectively. For tumour volumes measured by segmenting parallel planes, the maximum inter-slice distance that maintained acceptable measurement variability increased from 100 to 600 μm as tumour volume increased. Comparison of free breathing versus ventilated animals demonstrated that respiratory motion did not significantly change the measured volume. These results enable design of more efficient imaging studies by using the measured variability to estimate the time required to observe a significant change in tumour volume

  15. MRI volume measurement of the brain in schizophrenia

    International Nuclear Information System (INIS)

    Someya, Yasuhiro; Abe, Tetsuo; Asai, Kunihiko; Okubo, Yoshirou; Toru, Michio.

    1996-01-01

    The T1-weighted images of whole-brain three-dimensional MRI (thickness, 3 mm; interval, 3 mm) were obtained from schizophrenic patients and 20 healthy volunteers. Detailed volumetric measurement of each part in the brain was carried out. As the result, the volume of both ventricles and third ventriculus cerebri in the schizophrenic group was significantly larger than that of the control group. No significant difference was observed in terms of the volume of the bilateral frontal lobe, bilateral body of caudate nucleus division and right temporal lobe. The volume of bilateral hippocampus and left temporal lobe of the schizophrenic group was significantly smaller than that of the control group. Negative correlation was observed between symptoms and the right temporal lobe volume (r=-0.41) in the schizophrenic group. In the schizophrenic group, morphological abnormality was admitted in the hippocampus, ventriculus cerebri and left temporal lobe. The morphological abnormality of the right temporal lobe seemed to involve the expression of negative symptoms. (S.Y.)

  16. Inter- and intra-observer variation in soft-tissue sarcoma target definition.

    Science.gov (United States)

    Roberge, D; Skamene, T; Turcotte, R E; Powell, T; Saran, N; Freeman, C

    2011-08-01

    To evaluate inter- and intra-observer variability in gross tumor volume definition for adult limb/trunk soft tissue sarcomas. Imaging studies of 15 patients previously treated with preoperative radiation were used in this study. Five physicians (radiation oncologists, orthopedic surgeons and a musculoskeletal radiologist) were asked to contour each of the 15 tumors on T1-weighted, gadolinium-enhanced magnetic resonance images. These contours were drawn twice by each physician. The volume and center of mass coordinates for each gross tumor volume were extracted and a Boolean analysis was performed to measure the degree of volume overlap. The median standard deviation in gross tumor volumes across observers was 6.1% of the average volume (range: 1.8%-24.9%). There was remarkably little variation in the 3D position of the gross tumor volume center of mass. For the 15 patients, the standard deviation of the 3D distance between centers of mass ranged from 0.06 mm to 1.7 mm (median 0.1mm). Boolean analysis demonstrated that 53% to 90% of the gross tumor volume was common to all observers (median overlap: 79%). The standard deviation in gross tumor volumes on repeat contouring was 4.8% (range: 0.1-14.4%) with a standard deviation change in the position of the center of mass of 0.4mm (range: 0mm-2.6mm) and a median overlap of 93% (range: 73%-98%). Although significant inter-observer differences were seen in gross tumor volume definition of adult soft-tissue sarcoma, the center of mass of these volumes was remarkably consistent. Variations in volume definition did not correlate with tumor size. Radiation oncologists should not hesitate to review their contours with a colleague (surgeon, radiologist or fellow radiation oncologist) to ensure that they are not outliers in sarcoma gross tumor volume definition. Protocols should take into account variations in volume definition when considering tighter clinical target volumes. Copyright © 2011 Société française de radioth

  17. Assessment of tidal volume and thoracoabdominal motion using volume and flow-oriented incentive spirometers in healthy subjects

    Directory of Open Access Journals (Sweden)

    V.F. Parreira

    2005-07-01

    Full Text Available The objective of the present study was to evaluate incentive spirometers using volume- (Coach and Voldyne and flow-oriented (Triflo II and Respirex devices. Sixteen healthy subjects, 24 ± 4 years, 62 ± 12 kg, were studied. Respiratory variables were obtained by respiratory inductive plethysmography, with subjects in a semi-reclined position (45º. Tidal volume, respiratory frequency, minute ventilation, inspiratory duty cycle, mean inspiratory flow, and thoracoabdominal motion were measured. Statistical analysis was performed with Kolmogorov-Smirnov test, t-test and ANOVA. Comparison between the Coach and Voldyne devices showed that larger values of tidal volume (1035 ± 268 vs 947 ± 268 ml, P = 0.02 and minute ventilation (9.07 ± 3.61 vs 7.49 ± 2.58 l/min, P = 0.01 were reached with Voldyne, whereas no significant differences in respiratory frequency were observed (7.85 ± 1.24 vs 8.57 ± 1.89 bpm. Comparison between flow-oriented devices showed larger values of inspiratory duty cycle and lower mean inspiratory flow with Triflo II (0.35 ± 0.05 vs 0.32 ± 0.05 ml/s, P = 0.00, and 531 ± 137 vs 606 ± 167 ml/s, P = 0.00, respectively. Abdominal motion was larger (P < 0.05 during the use of volume-oriented devices compared to flow-oriented devices (52 ± 11% for Coach and 50 ± 9% for Voldyne; 43 ± 13% for Triflo II and 44 ± 14% for Respirex. We observed that significantly higher tidal volume associated with low respiratory frequency was reached with Voldyne, and that there was a larger abdominal displacement with volume-oriented devices.

  18. Provider volume and outcomes for oncological procedures.

    LENUS (Irish Health Repository)

    Killeen, S D

    2012-02-03

    BACKGROUND: Oncological procedures may have better outcomes if performed by high-volume providers. METHODS: A review of the English language literature incorporating searches of the Medline, Embase and Cochrane collaboration databases was performed. Studies were included if they involved a patient cohort from 1984 onwards, were community or population based, and assessed health outcome as a dependent variable and volume as an independent variable. The studies were also scored quantifiably to assess generalizability with respect to any observed volume-outcome relationship and analysed according to organ system; numbers needed to treat were estimated where possible. RESULTS: Sixty-eight relevant studies were identified and a total of 41 were included, of which 13 were based on clinical data. All showed either an inverse relationship, of variable magnitude, between provider volume and mortality, or no volume-outcome effect. All but two clinical reports revealed a statistically significant positive relationship between volume and outcome; none demonstrated the opposite. CONCLUSION: High-volume providers have a significantly better outcome for complex cancer surgery, specifically for pancreatectomy, oesphagectomy, gastrectomy and rectal resection.

  19. The study protocol of a cluster-randomised controlled trial of family-mediated personalised activities for nursing home residents with dementia.

    Science.gov (United States)

    van der Ploeg, Eva S; Camp, Cameron J; Eppingstall, Barbara; Runci, Susannah J; O'Connor, Daniel W

    2012-01-12

    Following admission to a nursing home, the feelings of depression and burden that family carers may experience do not necessarily diminish. Additionally, they may experience feelings of guilt and grief for the loss of a previously close relationship. At the same time, individuals with dementia may develop symptoms of depression and agitation (BPSD) that may be related to changes in family relationships, social interaction and stimulation. Until now, interventions to alleviate carer stress and BPSD have treated carers and relatives separately rather than focusing on maintaining or enhancing their relationships. One-to-one structured activities have been shown to reduce BPSD and also improve the caring experience, but barriers such as a lack of resources impede the implementation of activities in aged care facilities. The current study will investigate the effect of individualised activities based on the Montessori methodology administered by family carers in residential care. We will conduct a cluster-randomised trial to train family carers in conducting personalised one-to-one activities based on the Montessori methodology with their relatives. Montessori activities derive from the principles espoused by Maria Montessori and subsequent educational theorists to promote engagement in learning, namely task breakdown, guided repetition, progression in difficulty from simple to complex, and the careful matching of demands to levels of competence. Persons with dementia living in aged care facilities and frequently visiting family carers will be included in the study. Consented, willing participants will be randomly assigned by facility to a treatment condition using the Montessori approach or a control waiting list condition. We hypothesise that family carers conducting Montessori-based activities will experience improvements in quality of visits and overall relationship with the resident as well as higher self-rated mastery, fewer depressive symptoms, and a better

  20. The study protocol of a cluster-randomised controlled trial of family-mediated personalised activities for nursing home residents with dementia

    Directory of Open Access Journals (Sweden)

    van der Ploeg Eva S

    2012-01-01

    Full Text Available Abstract Background Following admission to a nursing home, the feelings of depression and burden that family carers may experience do not necessarily diminish. Additionally, they may experience feelings of guilt and grief for the loss of a previously close relationship. At the same time, individuals with dementia may develop symptoms of depression and agitation (BPSD that may be related to changes in family relationships, social interaction and stimulation. Until now, interventions to alleviate carer stress and BPSD have treated carers and relatives separately rather than focusing on maintaining or enhancing their relationships. One-to-one structured activities have been shown to reduce BPSD and also improve the caring experience, but barriers such as a lack of resources impede the implementation of activities in aged care facilities. The current study will investigate the effect of individualised activities based on the Montessori methodology administered by family carers in residential care. Methods/Design We will conduct a cluster-randomised trial to train family carers in conducting personalised one-to-one activities based on the Montessori methodology with their relatives. Montessori activities derive from the principles espoused by Maria Montessori and subsequent educational theorists to promote engagement in learning, namely task breakdown, guided repetition, progression in difficulty from simple to complex, and the careful matching of demands to levels of competence. Persons with dementia living in aged care facilities and frequently visiting family carers will be included in the study. Consented, willing participants will be randomly assigned by facility to a treatment condition using the Montessori approach or a control waiting list condition. We hypothesise that family carers conducting Montessori-based activities will experience improvements in quality of visits and overall relationship with the resident as well as higher self

  1. Data quality and practical challenges of thyroid volume assessment by ultrasound under field conditions - observer errors may affect prevalence estimates of goitre

    Directory of Open Access Journals (Sweden)

    Torheim Liv E

    2010-12-01

    Full Text Available Abstract Background The ultrasonographic estimation of thyroid size has been advocated as being more precise than palpation to diagnose goitre. However, ultrasound also requires technical proficiency. This study was conducted among Saharawi refugees, where goitre is highly prevalent. The objectives were to assess the overall data quality of ultrasound measurements of thyroid volume (Tvol, including the intra- and inter-observer agreement, under field conditions, and to describe some of the practical challenges encountered. Methods In 2007 a cross-sectional study of 419 children (6-14 years old and 405 women (15-45 years old was performed on a population of Saharawi refugees with prevalent goitre, who reside in the Algerian desert. Tvol was measured by two trained fieldworkers using portable ultrasound equipment (examiner 1 measured 406 individuals, and examiner 2, 418 individuals. Intra- and inter-observer agreement was estimated in 12 children selected from the study population but not part of the main study. In the main study, an observer error was found in one examiner whose ultrasound images were corrected by linear regression after printing and remeasuring a sample of 272 images. Results The intra-observer agreement in Tvol was higher in examiner 1, with an intraclass correlation coefficient (ICC of 0.97 (95% CI: 0.91, 0.99 compared to 0.86 (95% CI: 0.60, 0.96 in examiner 2. The ICC for inter-observer agreement in Tvol was 0.38 (95% CI: -0.20, 0.77. Linear regression coefficients indicated a significant scaling bias in the original measurements of the AP and ML diameter and a systematic underestimation of Tvol (a product of AP, ML, CC and a constant. The agreement between re-measured and original Tvol measured by ICC (95% CI was 0.76 (0.71, 0.81. The agreement between re-measured and corrected Tvol measured by ICC (95% CI was 0.97 (0.96, 0.97. Conclusions An important challenge when using ultrasound to assess thyroid volume under field

  2. Ouabain-Induced Cytoplasmic Vesicles and Their Role in Cell Volume Maintenance

    Directory of Open Access Journals (Sweden)

    M. A. Russo

    2015-01-01

    Full Text Available Cellular swelling is controlled by an active mechanism of cell volume regulation driven by a Na+/K+-dependent ATPase and by aquaporins which translocate water along the osmotic gradient. Na+/K+-pump may be blocked by ouabain, a digitalic derivative, by inhibition of ATP, or by drastic ion alterations of extracellular fluid. However, it has been observed that some tissues are still able to control their volume despite the presence of ouabain, suggesting the existence of other mechanisms of cell volume control. In 1977, by correlating electron microscopy observation with ion and water composition of liver slices incubated in different metabolic conditions in the presence or absence of ouabain, we observed that hepatocytes were able to control their volume extruding water and recovering ion composition in the presence of ouabain. In particular, hepatocytes were able to sequester ions and water in intracellular vesicles and then secrete them at the bile canaliculus pole. We named this “vesicular mechanism of cell volume control.” Afterward, this mechanism has been confirmed by us and other laboratories in several mammalian tissues. This review summarizes evidences regarding this mechanism, problems that are still pending, and questions that need to be answered. Finally, we shortly review the importance of cell volume control in some human pathological conditions.

  3. Fluctuations of trading volume in a stock market

    Science.gov (United States)

    Hong, Byoung Hee; Lee, Kyoung Eun; Hwang, Jun Kyung; Lee, Jae Woo

    2009-03-01

    We consider the probability distribution function of the trading volume and the volume changes in the Korean stock market. The probability distribution function of the trading volume shows double peaks and follows a power law, P(V/)∼( at the tail part of the distribution with α=4.15(4) for the KOSPI (Korea composite Stock Price Index) and α=4.22(2) for the KOSDAQ (Korea Securities Dealers Automated Quotations), where V is the trading volume and is the monthly average value of the trading volume. The second peaks originate from the increasing trends of the average volume. The probability distribution function of the volume changes also follows a power law, P(Vr)∼Vr-β, where Vr=V(t)-V(t-T) and T is a time lag. The exponents β depend on the time lag T. We observe that the exponents β for the KOSDAQ are larger than those for the KOSPI.

  4. The ultrasound-guided retrolaminar block: volume-dependent injectate distribution

    Directory of Open Access Journals (Sweden)

    Damjanovska M

    2018-02-01

    Full Text Available Marija Damjanovska,1 Tatjana Stopar Pintaric,1,2 Erika Cvetko,2 Kamen Vlassakov3 1Clinical Department of Anesthesiology and Intensive Therapy, University Medical Centre Ljubljana, Ljubljana, Slovenia; 2Institute of Anatomy, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia; 3Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA Purpose: The ultrasound-guided retrolaminar block is one of the newer and simpler alternatives to the traditional, often technically challenging, paravertebral (PV block. Its feasibility, safety, and efficacy have already been clinically demonstrated in patients with multiple rib fractures using higher volumes of local anesthetic, when compared with the traditional approach. The primary aim of this observational anatomical study was to assess the spread of local anesthetic from the retrolaminar injection point to the PV space and its volume dependence. Second, we assessed the incidence of epidural and contralateral PV spread in the both groups.Methods: Ten fresh porcine cadavers were randomized into 2 groups (n=5 each to receive ultrasound-guided retrolaminar injections at Th4-Th5 level with either 10 mL (low-volume group or 30 mL (high-volume group of 2% lidocaine and methylene blue mixture. After the procedure, the cadavers were dissected and frozen. Cross-section cuts (~1 cm thick were performed to evaluate the injectate spread.Results: In the high-volume group, injectate spread from the retrolaminar to the PV space was observed in all specimens (5 out of 5; 100%, while in the low-volume group, no apparent spread to the PV space was found (0 out of 5; 0%. No epidural or contralateral PV spread was observed in any of the specimens.Conclusion: Following ultrasound-guided retrolaminar injections in fresh porcine cadavers, injectate spread from the retrolaminar tissue plane to the PV space is strongly volume dependent

  5. Delivered volumes of enteral nutrition exceed prescribed volumes.

    Science.gov (United States)

    Walker, Renee Nichole; Utech, Anne; Velez, Maria Eugenia; Schwartz, Katie

    2014-10-01

    Enteral nutrition (EN) provisions are typically calculated based on a 24-hour infusion period. However, feedings are often interrupted for daily activities, procedures, or gastrointestinal intolerance. The study's objective was to determine the delivered EN quantities provided to stable hospitalized patients, using cellular time and measured volumes to verify our EN calculation adjustment. A supply of consecutively numbered ready-to-hang (RTH) EN product was delivered to the bedside of 26 inpatients with established EN tolerance at goal rates on various types of nursing units. The dietitian weighed the volume remaining in the infusing product and recorded the measurement time. On the following days, the dietitian continued to weigh the infusing RTH product and the empty RTH bottles saved by nursing. The primary outcome was the difference between the prescribed and delivered EN provisions, which was calculated with a paired t test. Patients received significantly more calories in the delivered enteral feeding (mean [SD], 1678 [385] kcal) than prescribed calories in the EN order (1489 [246 kcal]; t = 3.736, P = .001), adjusting for observed time. No significant differences were found between nursing units, product, and rate. EN delivered may actually exceed ordered amounts by 5%–21% (mean, 12%) with feeding pump inaccuracy as the primary contributing factor. This differs from what others have found. Our findings support using a volume-based ordering system vs a rate-based ordering system for more accurate EN delivery.

  6. Cosmological measure with volume averaging and the vacuum energy problem

    Science.gov (United States)

    Astashenok, Artyom V.; del Popolo, Antonino

    2012-04-01

    In this paper, we give a possible solution to the cosmological constant problem. It is shown that the traditional approach, based on volume weighting of probabilities, leads to an incoherent conclusion: the probability that a randomly chosen observer measures Λ = 0 is exactly equal to 1. Using an alternative, volume averaging measure, instead of volume weighting can explain why the cosmological constant is non-zero.

  7. Cosmological measure with volume averaging and the vacuum energy problem

    International Nuclear Information System (INIS)

    Astashenok, Artyom V; Del Popolo, Antonino

    2012-01-01

    In this paper, we give a possible solution to the cosmological constant problem. It is shown that the traditional approach, based on volume weighting of probabilities, leads to an incoherent conclusion: the probability that a randomly chosen observer measures Λ = 0 is exactly equal to 1. Using an alternative, volume averaging measure, instead of volume weighting can explain why the cosmological constant is non-zero. (paper)

  8. Effects of Anti-VEGF on Predicted Antibody Biodistribution: Roles of Vascular Volume, Interstitial Volume, and Blood Flow

    Science.gov (United States)

    Boswell, C. Andrew; Ferl, Gregory Z.; Mundo, Eduardo E.; Bumbaca, Daniela; Schweiger, Michelle G.; Theil, Frank-Peter; Fielder, Paul J.; Khawli, Leslie A.

    2011-01-01

    Background The identification of clinically meaningful and predictive models of disposition kinetics for cancer therapeutics is an ongoing pursuit in drug development. In particular, the growing interest in preclinical evaluation of anti-angiogenic agents alone or in combination with other drugs requires a complete understanding of the associated physiological consequences. Methodology/Principal Findings Technescan™ PYP™, a clinically utilized radiopharmaceutical, was used to measure tissue vascular volumes in beige nude mice that were naïve or administered a single intravenous bolus dose of a murine anti-vascular endothelial growth factor (anti-VEGF) antibody (10 mg/kg) 24 h prior to assay. Anti-VEGF had no significant effect (p>0.05) on the fractional vascular volumes of any tissues studied; these findings were further supported by single photon emission computed tomographic imaging. In addition, apart from a borderline significant increase (p = 0.048) in mean hepatic blood flow, no significant anti-VEGF-induced differences were observed (p>0.05) in two additional physiological parameters, interstitial fluid volume and the organ blood flow rate, measured using indium-111-pentetate and rubidium-86 chloride, respectively. Areas under the concentration-time curves generated by a physiologically-based pharmacokinetic model changed substantially (>25%) in several tissues when model parameters describing compartmental volumes and blood flow rates were switched from literature to our experimentally derived values. However, negligible changes in predicted tissue exposure were observed when comparing simulations based on parameters measured in naïve versus anti-VEGF-administered mice. Conclusions/Significance These observations may foster an enhanced understanding of anti-VEGF effects in murine tissues and, in particular, may be useful in modeling antibody uptake alone or in combination with anti-VEGF. PMID:21436893

  9. Practical Observations of the Transit of Venus

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 5. Practical Observations of the Transit of Venus. B S Shyalaja. Classroom Volume 9 Issue 5 May 2004 pp 79-83. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/009/05/0079-0083 ...

  10. A VOLUME-LIMITED PHOTOMETRIC SURVEY OF 114 γ DORADUS CANDIDATES

    International Nuclear Information System (INIS)

    Henry, Gregory W.; Fekel, Francis C.; Henry, Stephen M.

    2011-01-01

    We have carried out a photometric survey of a complete, volume-limited sample of γ Doradus candidates. The sample was extracted from the Hipparcos catalog and consists of 114 stars with colors and absolute magnitudes within the range of known γ Doradus stars and that also lie within a specified volume of 266,600 pc 3 . We devoted one year of observing time with our T12 0.8 m automatic photometric telescope to acquire nightly observations of the complete sample of stars. From these survey observations, we identify 37 stars with intrinsic variability of 0.002 mag or more. Of these 37 variables, 8 have already been confirmed as γ Doradus stars in our earlier papers; we scheduled the remaining 29 variables on our T3 0.4 m automatic telescope to acquire more intensive observations over the next two years. As promising new γ Doradus candidates were identified from the photometry, we obtained complementary spectroscopic observations of each candidate with the Kitt Peak coude feed telescope. Analysis of our new photometric and spectroscopic data reveals 15 new γ Doradus variables (and confirms two others), 8 new δ Scuti variables (and confirms one other), and 3 new variables with unresolved periodicity. Therefore, of the 114 γ Doradus candidates in our volume-limited sample, we find 25 stars that are new or previously known γ Doradus variables. This results in an incidence of 22% for γ Doradus variability among candidate field stars for this volume of the solar neighborhood. The corresponding space density of γ Doradus stars in this volume of space is 0.094 stars per 10 3 pc 3 or 94 stars per 10 6 pc 3 . We provide an updated list of 86 bright, confirmed, γ Doradus field stars.

  11. MANAGING HIGH-END, HIGH-VOLUME INNOVATIVE PRODUCTS

    Directory of Open Access Journals (Sweden)

    Gembong Baskoro

    2008-01-01

    Full Text Available This paper discuses the concept of managing high-end, high-volume innovative products. High-end, high-volume consumer products are products that have considerable influence to the way of life. Characteristic of High-end, high-volume consumer products are (1 short cycle time, (2 quick obsolete time, and (3 rapid price erosion. Beside the disadvantages that they are high risk for manufacturers, if manufacturers are able to understand precisely the consumer needs then they have the potential benefit or success to be the market leader. High innovation implies to high utilization of the user, therefore these products can influence indirectly to the way of people life. The objective of managing them is to achieve sustainability of the products development and innovation. This paper observes the behavior of these products in companies operated in high-end, high-volume consumer product.

  12. Stochastic dynamics of penetrable rods in one dimension: occupied volume and spatial order.

    Science.gov (United States)

    Craven, Galen T; Popov, Alexander V; Hernandez, Rigoberto

    2013-06-28

    The occupied volume of a penetrable hard rod (HR) system in one dimension is probed through the use of molecular dynamics simulations. In these dynamical simulations, collisions between penetrable rods are governed by a stochastic penetration algorithm (SPA), which allows for rods to either interpenetrate with a probability δ, or collide elastically otherwise. The limiting values of this parameter, δ = 0 and δ = 1, correspond to the HR and the ideal limits, respectively. At intermediate values, 0 exclusive and independent events is observed, making prediction of the occupied volume nontrivial. At high hard core volume fractions φ0, the occupied volume expression derived by Rikvold and Stell [J. Chem. Phys. 82, 1014 (1985)] for permeable systems does not accurately predict the occupied volume measured from the SPA simulations. Multi-body effects contribute significantly to the pair correlation function g2(r) and the simplification by Rikvold and Stell that g2(r) = δ in the penetrative region is observed to be inaccurate for the SPA model. We find that an integral over the penetrative region of g2(r) is the principal quantity that describes the particle overlap ratios corresponding to the observed penetration probabilities. Analytic formulas are developed to predict the occupied volume of mixed systems and agreement is observed between these theoretical predictions and the results measured from simulation.

  13. Reduced volume of Heschl's gyrus in tinnitus.

    Science.gov (United States)

    Schneider, Peter; Andermann, Martin; Wengenroth, Martina; Goebel, Rainer; Flor, Herta; Rupp, André; Diesch, Eugen

    2009-04-15

    The neural basis of tinnitus is unknown. Recent neuroimaging studies point towards involvement of several cortical and subcortical regions. Here we demonstrate that tinnitus may be associated with structural changes in the auditory cortex. Using individual morphological segmentation, the medial partition of Heschl's gyrus (mHG) was studied in individuals with and without chronic tinnitus using magnetic resonance imaging. Both the tinnitus and the non-tinnitus group included musicians and non-musicians. Patients exhibited significantly smaller mHG gray matter volumes than controls. In unilateral tinnitus, this effect was almost exclusively seen in the hemisphere ipsilateral to the affected ear. In bilateral tinnitus, mHG volume was substantially reduced in both hemispheres. The tinnitus-related volume reduction was found across the full extent of mHG, not only in the high-frequency part usually most affected by hearing loss-induced deafferentation. However, there was also evidence for a relationship between volume reduction and hearing loss. Correlations between volume and hearing level depended on the subject group as well as the asymmetry of the hearing loss. The volume changes observed may represent antecedents or consequences of tinnitus and tinnitus-associated hearing loss and also raise the possibility that small cortical volume constitutes a vulnerability factor.

  14. Weekly Volume and Dosimetric Changes During Chemoradiotherapy With Intensity-Modulated Radiation Therapy for Head and Neck Cancer: A Prospective Observational Study

    Energy Technology Data Exchange (ETDEWEB)

    Bhide, Shreerang A [Institute of Cancer Research, 237 Fulham Road, London SW6 6JB (United Kingdom); Head and Neck Unit, Royal Marsden NHS Foundation Trust Hospital, London SW3 6JJ (United Kingdom); Davies, Mark; Burke, Kevin; McNair, Helen A; Hansen, Vibeke [Department of Radiation Oncology, Royal Marsden NHS Foundation Trust Hospital, London and Sutton (United Kingdom); Barbachano, Y [Department of Statistics, Royal Marsden NHS Foundation Trust Hospital, London and Sutton (United Kingdom); El-Hariry, I A [Head and Neck Unit, Royal Marsden NHS Foundation Trust Hospital, London SW3 6JJ (United Kingdom); Newbold, Kate [Department of Radiation Oncology, Royal Marsden NHS Foundation Trust Hospital, London and Sutton (United Kingdom); Harrington, Kevin J [Institute of Cancer Research, 237 Fulham Road, London SW6 6JB (United Kingdom); Head and Neck Unit, Royal Marsden NHS Foundation Trust Hospital, London SW3 6JJ (United Kingdom); Nutting, Christopher M., E-mail: chris.nutting@rmh.nhs.u [Head and Neck Unit, Royal Marsden NHS Foundation Trust Hospital, London SW3 6JJ (United Kingdom)

    2010-04-15

    Purpose: The aim of this study was to investigate prospectively the weekly volume changes in the target volumes and organs at risk and the resulting dosimetric changes during induction chemotherapy followed by chemoradiotherapy with intensity-modulated radiation therapy (C-IMRT) for head-and-neck cancer patients. Methods and Materials: Patients receiving C-IMRT for head-and-neck cancer had repeat CT scans at weeks 2, 3, 4, and 5 during radiotherapy. The volume changes of clinical target volume 1 (CTV1) and CTV2 and the resulting dosimetric changes to planning target volume 1 (PTV1) and PTV2 and the organs at risk were measured. Results: The most significant volume differences were seen at week 2 for CTV1 and CTV2. The reductions in the volumes of CTV1 and CTV2 at week 2 were 3.2% and 10%, respectively (p = 0.003 and p < 0.001). The volume changes resulted in a significant reduction in the minimum dose to PTV1 and PTV2 (2 Gy, p = 0.002, and 3.9 Gy, p = 0.03, respectively) and an increased dose range across PTV1 and PTV2 (2.5 Gy, p < 0.001, and 5.1 Gy, p = 0.008, respectively). There was a 15% reduction in the parotid volumes by week 2 (p < 0.001) and 31% by week 4 (p < 0.001). There was a statistically significant increase in the mean dose to the ipsilateral parotid only at week 4 (2.7 Gy, p = 0.006). The parotid glands shifted medially by an average of 2.3 mm (p < 0.001) by week 4. Conclusion: The most significant volumetric changes and dosimetric alterations in the tumor volumes and organs at risk during a course of C-IMRT occur by week 2 of radiotherapy. Further adaptive radiotherapy with replanning, if appropriate, is recommended.

  15. Volume dependence of the melting temperature for alkali metals with Debye's model

    International Nuclear Information System (INIS)

    Soma, T.; Kagaya, H.M.; Nishigaki, M.

    1983-01-01

    Using the volume dependence of the Grueneisen constant at higher temperatures, the volume effect on the melting temperature of alkali metals is studied by Lindeman's melting law and Debye's model. The obtained melting curve increases as a function of the compressed volume and shows the maximum of the melting point at the characteristic volume. The resultant data are qualitatively in agreement with the observed tendency for alkali metals. (author)

  16. Case mix-adjusted cost of colectomy at low-, middle-, and high-volume academic centers.

    Science.gov (United States)

    Chang, Alex L; Kim, Young; Ertel, Audrey E; Hoehn, Richard S; Wima, Koffi; Abbott, Daniel E; Shah, Shimul A

    2017-05-01

    Efforts to regionalize surgery based on thresholds in procedure volume may have consequences on the cost of health care delivery. This study aims to delineate the relationship between hospital volume, case mix, and variability in the cost of operative intervention using colectomy as the model. All patients undergoing colectomy (n = 90,583) at 183 academic hospitals from 2009-2012 in The University HealthSystems Consortium Database were studied. Patient and procedure details were used to generate a case mix-adjusted predictive model of total direct costs. Observed to expected costs for each center were evaluated between centers based on overall procedure volume. Patient and procedure characteristics were significantly different between volume tertiles. Observed costs at high-volume centers were less than at middle- and low-volume centers. According to our predictive model, high-volume centers cared for a less expensive case mix than middle- and low-volume centers ($12,786 vs $13,236 and $14,497, P case mix at low-volume centers, which may lead to perceived poor performance at these centers. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Visibility of microcalcification clusters and masses in breast tomosynthesis image volumes and digital mammography: A 4AFC human observer study

    International Nuclear Information System (INIS)

    Timberg, P.; Baath, M.; Andersson, I.; Mattsson, S.; Tingberg, A.; Ruschin, M.

    2012-01-01

    Purpose: To investigate the visibility of simulated lesions in digital breast tomosynthesis (BT) image volumes compared with 2D digital mammography (DM). Methods: Simulated lesions (masses and microcalcifications) were added to images of the same women acquired on a DM system (Mammomat Novation, Siemens) and a BT prototype. The same beam quality was used for the DM and BT acquisitions. The total absorbed dose resulting from a 25-projection BT acquisition and reconstruction (BT 25 ) was approximately twice that of a single DM view. By excluding every other projection image from the reconstruction (BT 13 ), approximately the same dose as in DM was effected. Simulated microcalcifications were digitally added with varying contrast to the DM and BT images. Simulated masses with 8 mm diameter were also added to BT images. A series of 4-alternative forced choice (4AFC) human observer experiments were conducted. Four medical physicists participated in all experiments, each consisting of 60 trials per experimental condition. The observers interpreted the BT image volumes in cine-mode at a fixed image sequence speed. The required threshold contrast (S t ) to achieve a detectability index (d') of 2.5 (i.e., 92.5% correct decisions) was determined. Results: The S t for mass detection in DM was approximately a factor of 2 higher than required in BT indicating that the detection of masses was improved under BT conditions compared to DM. S t for microcalcification detection was higher for BT than for DM at both BT dose levels (BT 25 and BT 13 ), with a statistically significant difference in S t between DM and BT 13 . These results indicate a dose-dependent decrease in detection performance in BT for detection of microcalcifications. Conclusions: In agreement with previous investigations, masses of size 8 mm can be detected with less contrast in BT than in DM indicating improved detection performance for BT. However, for the investigated microcalcifications, the results of this

  18. A glimpse beneath Antarctic sea ice: observation of platelet-layer thickness and ice-volume fraction with multifrequency EM

    Science.gov (United States)

    Hoppmann, Mario; Hunkeler, Priska A.; Hendricks, Stefan; Kalscheuer, Thomas; Gerdes, Rüdiger

    2016-04-01

    In Antarctica, ice crystals (platelets) form and grow in supercooled waters below ice shelves. These platelets rise, accumulate beneath nearby sea ice, and subsequently form a several meter thick, porous sub-ice platelet layer. This special ice type is a unique habitat, influences sea-ice mass and energy balance, and its volume can be interpreted as an indicator of the health of an ice shelf. Although progress has been made in determining and understanding its spatio-temporal variability based on point measurements, an investigation of this phenomenon on a larger scale remains a challenge due to logistical constraints and a lack of suitable methodology. In the present study, we applied a lateral constrained Marquardt-Levenberg inversion to a unique multi-frequency electromagnetic (EM) induction sounding dataset obtained on the ice-shelf influenced fast-ice regime of Atka Bay, eastern Weddell Sea. We adapted the inversion algorithm to incorporate a sensor specific signal bias, and confirmed the reliability of the algorithm by performing a sensitivity study using synthetic data. We inverted the field data for sea-ice and platelet-layer thickness and electrical conductivity, and calculated ice-volume fractions within the platelet layer using Archie's Law. The thickness results agreed well with drillhole validation datasets within the uncertainty range, and the ice-volume fraction yielded results comparable to other studies. Both parameters together enable an estimation of the total ice volume within the platelet layer, which was found to be comparable to the volume of landfast sea ice in this region, and corresponded to more than a quarter of the annual basal melt volume of the nearby Ekström Ice Shelf. Our findings show that multi-frequency EM induction sounding is a suitable approach to efficiently map sea-ice and platelet-layer properties, with important implications for research into ocean/ice-shelf/sea-ice interactions. However, a successful application of this

  19. Computed Tomography Colonography Technique: The Role of Intracolonic Gas Volume

    Directory of Open Access Journals (Sweden)

    Patrick D. McLaughlin

    2013-01-01

    Full Text Available Introduction. Poor distention decreases the sensitivity and specificity of CTC. The total volume of gas administered will vary according to many factors. We aim to determine the relationship between the volume of retained gas at the time of image acquisition and colonic distention and specifically the presence of collapsed bowel segments at CTC. Materials and Methods. All patients who underwent CTC over a 12-month period at a single institution were included in the study. Colonic luminal distention was objectively scored by 2 radiologists using an established 4-point scale. Quantitative analysis of the volume of retained gas at the time of image acquisition was conducted using the threshold 3D region growing function of OsiriX. Results. 108 patients were included for volumetric analysis. Mean retained gas volume was 3.3 L. 35% (38/108 of patients had at least one collapsed colonic segment. Significantly lower gas volumes were observed in the patients with collapsed colonic segments when compared with those with fully distended colons 2.6 L versus 3.5 L (P=0.031. Retained volumes were significantly higher for the 78% of patients with ileocecal reflux at 3.4 L versus 2.6 L without ileocecal reflux (P=0.014. Conclusion. Estimation of intraluminal gas volume at CTC is feasible using image segmentation and thresholding tools. An average of 3.5 L of retained gas was found in diagnostically adequate CTC studies with significantly lower mean gas volume observed in patients with collapsed colonic segments.

  20. Finite volume QCD at fixed topological charge

    OpenAIRE

    Aoki, Sinya; Fukaya, Hidenori; Hashimoto, Shoji; Onogi, Tetsuya

    2007-01-01

    In finite volume the partition function of QCD with a given $\\theta$ is a sum of different topological sectors with a weight primarily determined by the topological susceptibility. If a physical observable is evaluated only in a fixed topological sector, the result deviates from the true expectation value by an amount proportional to the inverse space-time volume 1/V. Using the saddle point expansion, we derive formulas to express the correction due to the fixed topological charge in terms of...

  1. Dosimetric impact of prostate volume change between CT-based HDR brachytherapy fractions

    International Nuclear Information System (INIS)

    Kim, Yongbok; Hsu, I-C.; Lessard, Etienne; Vujic, Jasmina; Pouliot, Jean

    2004-01-01

    Purpose: The objective is to evaluate the prostate volume change and its dosimetric consequences after the insertion of catheters for high-dose-rate brachytherapy. Methods and Materials: For 13 consecutive patients, a spiral CT scan was acquired before each of the 2 fractions, separated on average by 20 hours. The coordinates of the catheters were obtained on 3 axial CT slices corresponding to apex, mid portion, and base portion of the prostate. A mathematical expansion model was used to evaluate the change of prostate volumes between the 2 fractions. It is based on the difference in the cube of the average distance between the centroid and catheter positions. The variation of implant dose-volume histograms between fractions was computed for plans produced by either inverse planning based on simulated annealing or geometric optimization. Results: The average magnitude of either increase or reduction in prostate volume was 7.8% (range, 2-17%). This volume change corresponds to an average prostate radius change of only 2.5% (range, 0.7-5.4%). For 5 patients, the prostate volume increased on average by 9% (range, 2-17%), whereas a reduction was observed for 8 patients by an average of 7% (range, 2-13%). More variation was observed at the prostate base than at mid or apex gland. The comparison of implant dose-volume histograms showed a small reduction of V100 receiving the prescription dose, with an average of 3.5% (range, 0.5-12%) and 2.2% (range, 1-6%) for inverse planning based on our simulated annealing and geometric optimization plans, respectively. Conclusion: Small volume change was observed between treatment fractions. This translates into small changes in dose delivered to the prostate volume

  2. A role of decision-making competency in science learning utilizing a social valuation framework

    Science.gov (United States)

    Katsuo, Akihito

    2005-11-01

    The role of decision-making in learning performance has been an occasional topic in the research literature in science education, but rarely has it been a central issue in the field. Nonetheless, recent studies regarding the topic in several fields other than education, such as cognitive neuroscience and social choice theory, indicate the fundamental importance(s) of the topic. This study focuses on a possible role of decision-making in science learning. Initially the study was designed to probe the decision-making ability of elementary school children with a modified version of the Iowa Gambling Task (IGT). The experiment involved six Montessori 3rd and 4th grade students as the experimental group and eight public school 3rd and 4th grade students as the control group. The result of the modified IGT revealed a tendency in choice trajectories favoring children at the Montessori school. However, the probabilistic value went below the statistically significant level set by the U test. A further study focused on the impact of better decision-making ability revealed in the first experiment on performances with a science learning module that emphasized collective reasoning. The instruction was based on a set of worksheets with multiple choices on which students were asked to make predictions with and to provide supportive arguments regarding outcomes of experiments introduced in the worksheet. Then the whole class was involved with a real experiment to see which choice was correct. The findings in the study indicated that the Montessori students often obtained higher scores than non-Montessori students in making decision with a tendency of consistency in terms of their choices of the alternatives on the worksheets. The findings of the experiments were supported by a correlational analysis that was performed at the end of study. Although no statistically significant correlations were found, there was a tendency for positively associative shifts between the scores of the

  3. A database of worldwide glacier thickness observations

    DEFF Research Database (Denmark)

    Gärtner-Roer, I.; Naegeli, K.; Huss, M.

    2014-01-01

    One of the grand challenges in glacier research is to assess the total ice volume and its global distribution. Over the past few decades the compilation of a world glacier inventory has been well-advanced both in institutional set-up and in spatial coverage. The inventory is restricted to glacier...... the different estimation approaches. This initial database of glacier and ice caps thickness will hopefully be further enlarged and intensively used for a better understanding of the global glacier ice volume and its distribution....... surface observations. However, although thickness has been observed on many glaciers and ice caps around the globe, it has not yet been published in the shape of a readily available database. Here, we present a standardized database of glacier thickness observations compiled by an extensive literature...... review and from airborne data extracted from NASA's Operation IceBridge. This database contains ice thickness observations from roughly 1100 glaciers and ice caps including 550 glacier-wide estimates and 750,000 point observations. A comparison of these observational ice thicknesses with results from...

  4. Assessment of Uncertainty-Based Screening Volumes for NASA Robotic LEO and GEO Conjunction Risk Assessment

    Science.gov (United States)

    Narvet, Steven W.; Frigm, Ryan C.; Hejduk, Matthew D.

    2011-01-01

    Conjunction Assessment operations require screening assets against the space object catalog by placing a pre-determined spatial volume around each asset and predicting when another object will violate that volume. The selection of the screening volume used for each spacecraft is a trade-off between observing all conjunction events that may pose a potential risk to the primary spacecraft and the ability to analyze those predicted events. If the screening volumes are larger, then more conjunctions can be observed and therefore the probability of a missed detection of a high risk conjunction event is small; however, the amount of data which needs to be analyzed increases. This paper characterizes the sensitivity of screening volume size to capturing typical orbit uncertainties and the expected number of conjunction events observed. These sensitivities are quantified in the form of a trade space that allows for selection of appropriate screen-ing volumes to fit the desired concept of operations, system limitations, and tolerable analyst workloads. This analysis will specifically highlight the screening volume determination and selection process for use in the NASA Conjunction Assessment Risk Analysis process but will also provide a general framework for other Owner / Operators faced with similar decisions.

  5. First Simultaneous and Common-Volume Lidar Observations of Na and Fe Metals, Temperatures, and Vertical Winds in Antarctica

    Science.gov (United States)

    Chu, X.

    2017-12-01

    A new STAR Na Doppler lidar will be installed to Arrival Heights near McMurdo Station, Antarctica in October 2017. This new lidar will be operated next to an existing Fe Boltzmann lidar to make simultaneous and common-volume measurements of metal Na and Fe layers, neutral temperatures, and vertical winds in the mesosphere and thermosphere, up to nearly 200 km. These measurements will be used to study a variety of science topics, e.g., the meteoric metal layers, wave dynamics, polar mesospheric clouds, constituent and heat fluxes, and cosmic dust. The discoveries of thermospheric neutral Fe layers and persistent gravity waves by the Fe Boltzmann lidar observations has opened a new door to explore the space-atmosphere interactions with ground-based instruments, especially in the least understood but crucially important altitude range of 100-200 km. These neutral metal layers provide excellent tracers for modern resonance lidars to measure the neutral wind and temperature directly. Even more exciting, the neutral metal layers in the thermosphere provide a natural laboratory to test our fundamental understandings of the atmosphere-ionosphere-magnetosphere coupling and processes. This paper will report the first summer results from the simultaneous Na and Fe lidar observations from Antarctica, and highlight important discoveries made by the Fe lidar during its first seven years of campaign at McMurdo. A thermosphere-ionosphere Fe/Fe+ (TIFe) model will be introduced to explain the TIFe layers in Antarctica.

  6. Partial molar volumes of proteins: amino acid side-chain contributions derived from the partial molar volumes of some tripeptides over the temperature range 10-90 degrees C.

    Science.gov (United States)

    Häckel, M; Hinz, H J; Hedwig, G R

    1999-11-15

    The partial molar volumes of tripeptides of sequence glycyl-X-glycine, where X is one of the amino acids alanine, leucine, threonine, glutamine, phenylalanine, histidine, cysteine, proline, glutamic acid, and arginine, have been determined in aqueous solution over the temperature range 10-90 degrees C using differential scanning densitometry . These data, together with those reported previously, have been used to derive the partial molar volumes of the side-chains of all 20 amino acids. The side-chain volumes are critically compared with literature values derived using partial molar volumes for alternative model compounds. The new amino acid side-chain volumes, along with that for the backbone glycyl group, were used to calculate the partial specific volumes of several proteins in aqueous solution. The results obtained are compared with those observed experimentally. The new side-chain volumes have also been used to re-determine residue volume changes upon protein folding.

  7. Helium-induced blistering and volume swelling in nickel

    International Nuclear Information System (INIS)

    Fenske, G.R.

    1980-01-01

    The results of an experimental investigation of helium-induced blistering are presented. The goal of the research was to examine the mechanisms involved in blistering by observing the microstructure of the implanted region using transmission electron microscopy (TEM). In particular, the volume swelling was measured as a function of the implant depth, and compared to experimental skin thicknesses in order to determine if the skin separated at the maximum volume swelling, or at the end of the swelling profile

  8. THE PREDICTION OF VOID VOLUME IN SUBCOOLED NUCLEATE POOL BOILING

    Energy Technology Data Exchange (ETDEWEB)

    Duke, E. E. [General Dynamics, San Diego, CA (United States)

    1963-11-15

    A three- step equation was developed that adequately describes the average volume of vapor occurring on a horizontal surface due to nucleate pool boiling of subcooled water. Since extensive bubble frequency data are lacking, the data of others were combined with experimental observations to make predictions of void volume at ambient pressure with various degrees of subcooling. (auth)

  9. Observational constraints on loop quantum cosmology.

    Science.gov (United States)

    Bojowald, Martin; Calcagni, Gianluca; Tsujikawa, Shinji

    2011-11-18

    In the inflationary scenario of loop quantum cosmology in the presence of inverse-volume corrections, we give analytic formulas for the power spectra of scalar and tensor perturbations convenient to compare with observations. Since inverse-volume corrections can provide strong contributions to the running spectral indices, inclusion of terms higher than the second-order runnings in the power spectra is crucially important. Using the recent data of cosmic microwave background and other cosmological experiments, we place bounds on the quantum corrections.

  10. Brain volume measurement using three-dimensional magnetic resonance images

    International Nuclear Information System (INIS)

    Ishimaru, Yoshihiro

    1996-01-01

    This study was designed to validate accurate measurement method of human brain volume using three dimensional (3D) MRI data on a workstation, and to establish optimal correcting method of human brain volume on diagnosis of brain atrophy. 3D MRI data were acquired by fast SPGR sequence using 1.5 T MR imager. 3D MRI data were segmented by region growing method and 3D image was displayed by surface rendering method on the workstation. Brain volume was measured by the volume measurement function of the workstation. In order to validate the accurate measurement method, phantoms and a specimen of human brain were examined. Phantom volume was measured by changing the lower level of threshold value. At the appropriate threshold value, percentage of error of phantoms and the specimen were within 0.6% and 0.08%, respectively. To establish the optimal correcting method, 130 normal volunteers were examined. Brain volumes corrected with height weight, body surface area, and alternative skull volume were evaluated. Brain volume index, which is defined as dividing brain volume by alternative skull volume, had the best correlation with age (r=0.624, p<0.05). No gender differences was observed in brain volume index in contrast to in brain volume. The clinical usefulness of this correcting method for brain atrophy diagnosis was evaluated in 85 patients. Diagnosis by 2D spin echo MR images was compared with brain volume index. Diagnosis of brain atrophy by 2D MR image was concordant with the evaluation by brain volume index. These results indicated that this measurement method had high accuracy, and it was important to set the appropriate threshold value. Brain volume index was the appropriate indication for evaluation of human brain volume, and was considered to be useful for the diagnosis of brain atrophy. (author)

  11. Drusen Volume and Retinal Pigment Epithelium Abnormal Thinning Volume Predict 2-Year Progression of Age-Related Macular Degeneration.

    Science.gov (United States)

    Folgar, Francisco A; Yuan, Eric L; Sevilla, Monica B; Chiu, Stephanie J; Farsiu, Sina; Chew, Emily Y; Toth, Cynthia A

    2016-01-01

    To analyze the value of novel measures of retinal pigment epithelium-drusen complex (RPEDC) volume to predict 2-year disease progression of intermediate age-related macular degeneration (AMD). Prospective, observational study. Three hundred forty-five AMD and 122 non-AMD participants enrolled in the Age Related Eye Disease Study 2 Ancillary Spectral-Domain (SD) Optical Coherence Tomography (OCT) study. High-density SD OCT macular volumes were obtained at yearly study visits. The RPEDC abnormal thickening (henceforth, OCT drusen) and RPEDC abnormal thinning (RAT) volumes were generated by semiautomated segmentation of total RPEDC within a 5-mm-diameter macular field. Volume change and odds ratio (OR) with 95% confidence intervals (CI) for progression to advanced AMD with choroidal neovascularization (CNV) or central geographic atrophy (GA). Complete volumes were obtained in 265 and 266 AMD eyes and in 115 and 97 control eyes at baseline and at year 2, respectively. In AMD eyes, mean (standard deviation) OCT drusen volume increased from 0.08 mm(3) (0.16 mm(3)) to 0.10 mm(3) (0.23 mm(3); P < 0.001), and RAT volume increased from 8.3 × 10(-4) mm(3) (20.8 × 10(-4) mm(3)) to 18.4 × 10(-4) mm(3) (46.6 × 10(-4) mm(3); P < 0.001). Greater baseline OCT drusen volume was associated with 2-year progression to CNV (P = 0.002). Odds of developing CNV increased by 31% for every 0.1-mm(3) increase in baseline OCT drusen volume (OR, 1.31; 95% CI, 1.06-1.63; P = 0.013). Greater baseline RAT volume was associated with significant 2-year increase in RAT volume (P < 0.001), noncentral GA (P < 0.001), and progression to central GA (P < 0.001). Odds of developing central GA increased by 32% for every 0.001-mm(3) increase in baseline RAT volume (OR, 1.32; 95% CI, 1.14-1.53; P < 0.001). In non-AMD eyes, all volumes were significantly lower than AMD eyes and showed no significant 2-year change. Macular OCT drusen and RAT volumes increased significantly in AMD eyes over 2 years

  12. Altitude Acclimatization and Blood Volume: Effects of Exogenous Erythrocyte Volume Expansion

    National Research Council Canada - National Science Library

    Sawka, M

    1996-01-01

    ...: (a) altitude acclimatization effects on erythrocyte volume and plasma volume; (b) if exogenous erythrocyte volume expansion alters subsequent erythrocyte volume and plasma volume adaptations; (c...

  13. Inner volume leakage during integrated leakage rate testing

    International Nuclear Information System (INIS)

    Glover, J.P.

    1987-01-01

    During an integrated leak rate test (ILRT), the containment structure is maintained at test pressure with most penetrations isolated. Since penetrations typically employ dual isolation, the possibility exists for the inner isolation to leak while the outer holds. In this case, the ILRT instrumentation system would indicate containment out-leakage when, in fact, only the inner volume between closures is being pressurized. The problem is compounded because this false leakage is not readily observable outside of containment by standard leak inspection techniques. The inner volume leakage eventually subsides after the affected volumes reach test pressure. Depending on the magnitude of leakage and the size of the volumes, equalization could occur prior to the end of the pretest stabilization period, or significant false leakages may persist throughout the entire test. Two simple analyses were performed to quantify the effects of inside volume leakages. First, a lower bound for the equalization time was found. A second analysis was performed to find an approximate upper bound for the stabilization time. The results of both analyses are shown

  14. Correlated volume-energy fluctuations of phospholipid membranes: A simulation study

    DEFF Research Database (Denmark)

    Pedersen, Ulf. R.; Peters, Günther H.J.; Schröder, Thomas B.

    2010-01-01

    This paper reports all-atom computer simulations of five phospholipid membranes (DMPC, DPPC, DMPG, DMPS, and DMPSH) with focus on the thermal equilibrium fluctuations of volume, energy, area, thickness, and chain order. At constant temperature and pressure, volume and energy exhibit strong...... membranes, showing a similar picture. The cause of the observed strong correlations is identified by splitting volume and energy into contributions from tails, heads, and water, and showing that the slow volume−energy fluctuations derive from van der Waals interactions of the tail region; they are thus...

  15. Infrared observations of gravitational-wave sources in Advanced LIGO's second observing run

    Science.gov (United States)

    Pound Singer, Leo; Kasliwal, Mansi; Lau, Ryan; Cenko, Bradley; Global Relay of Observatories Watching Transients Happen (GROWTH)

    2018-01-01

    Advanced LIGO observed gravitational waves (GWs) from a binary black hole merger in its first observing run (O1) in September 2015. It is anticipated that LIGO and Virgo will soon detect the first binary neutron star mergers. The most promising electromagnetic counterparts to such events are kilonovae: fast, faint transients powered by the radioactive decay of the r-process ejecta. Joint gravitational-wave and electromagnetic observations of such transients hold the key to many longstanding problems, from the nature of short GRBS to the cosmic production sites of the r-process elements to "standard siren" cosmology. Due to the large LIGO/Virgo error regions of 100 deg2, synoptic survey telescopes have dominated the search for LIGO counterparts. Due to the paucity of infrared instruments with multi-deg2 fields of view, infrared observations have been lacking. Near-infrared emission should not only be a more robust signature of kilonovae than optical emission (independent of viewing angle), but should also be several magnitudes brighter and be detectable for much longer, weeks after merger rather than days. In Advanced LIGO's second observing run, we used the FLAMINGOS-2 instrument on Gemini-South to hunt for the near-infrared emission from GW sources by targeted imaging of the most massive galaxies in the LIGO/Virgo localization volumes. We present the results of this campaign, rates, and interpretation of our near-infrared imaging and spectroscopy. We show that leveraging large-scale structure and targeted imaging of the most massive ~10 galaxies in a LIGO/Virgo localization volume may be a surprisingly effective strategy to find the electromagnetic counterpart.

  16. MRI Volume Fusion Based on 3D Shearlet Decompositions.

    Science.gov (United States)

    Duan, Chang; Wang, Shuai; Wang, Xue Gang; Huang, Qi Hong

    2014-01-01

    Nowadays many MRI scans can give 3D volume data with different contrasts, but the observers may want to view various contrasts in the same 3D volume. The conventional 2D medical fusion methods can only fuse the 3D volume data layer by layer, which may lead to the loss of interframe correlative information. In this paper, a novel 3D medical volume fusion method based on 3D band limited shearlet transform (3D BLST) is proposed. And this method is evaluated upon MRI T2* and quantitative susceptibility mapping data of 4 human brains. Both the perspective impression and the quality indices indicate that the proposed method has a better performance than conventional 2D wavelet, DT CWT, and 3D wavelet, DT CWT based fusion methods.

  17. MRI Volume Fusion Based on 3D Shearlet Decompositions

    Directory of Open Access Journals (Sweden)

    Chang Duan

    2014-01-01

    Full Text Available Nowadays many MRI scans can give 3D volume data with different contrasts, but the observers may want to view various contrasts in the same 3D volume. The conventional 2D medical fusion methods can only fuse the 3D volume data layer by layer, which may lead to the loss of interframe correlative information. In this paper, a novel 3D medical volume fusion method based on 3D band limited shearlet transform (3D BLST is proposed. And this method is evaluated upon MRI T2* and quantitative susceptibility mapping data of 4 human brains. Both the perspective impression and the quality indices indicate that the proposed method has a better performance than conventional 2D wavelet, DT CWT, and 3D wavelet, DT CWT based fusion methods.

  18. Note: Nonpolar solute partial molar volume response to attractive interactions with water

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Steven M.; Ashbaugh, Henry S., E-mail: hanka@tulane.edu [Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana 70118 (United States)

    2014-01-07

    The impact of attractive interactions on the partial molar volumes of methane-like solutes in water is characterized using molecular simulations. Attractions account for a significant 20% volume drop between a repulsive Weeks-Chandler-Andersen and full Lennard-Jones description of methane interactions. The response of the volume to interaction perturbations is characterized by linear fits to our simulations and a rigorous statistical thermodynamic expression for the derivative of the volume to increasing attractions. While a weak non-linear response is observed, an average effective slope accurately captures the volume decrease. This response, however, is anticipated to become more non-linear with increasing solute size.

  19. Note: Nonpolar solute partial molar volume response to attractive interactions with water.

    Science.gov (United States)

    Williams, Steven M; Ashbaugh, Henry S

    2014-01-07

    The impact of attractive interactions on the partial molar volumes of methane-like solutes in water is characterized using molecular simulations. Attractions account for a significant 20% volume drop between a repulsive Weeks-Chandler-Andersen and full Lennard-Jones description of methane interactions. The response of the volume to interaction perturbations is characterized by linear fits to our simulations and a rigorous statistical thermodynamic expression for the derivative of the volume to increasing attractions. While a weak non-linear response is observed, an average effective slope accurately captures the volume decrease. This response, however, is anticipated to become more non-linear with increasing solute size.

  20. Public-Private Partnership: Joint recommendations to improve downloads of large Earth observation data

    Science.gov (United States)

    Ramachandran, R.; Murphy, K. J.; Baynes, K.; Lynnes, C.

    2016-12-01

    With the volume of Earth observation data expanding rapidly, cloud computing is quickly changing the way Earth observation data is processed, analyzed, and visualized. The cloud infrastructure provides the flexibility to scale up to large volumes of data and handle high velocity data streams efficiently. Having freely available Earth observation data collocated on a cloud infrastructure creates opportunities for innovation and value-added data re-use in ways unforeseen by the original data provider. These innovations spur new industries and applications and spawn new scientific pathways that were previously limited due to data volume and computational infrastructure issues. NASA, in collaboration with Amazon, Google, and Microsoft, have jointly developed a set of recommendations to enable efficient transfer of Earth observation data from existing data systems to a cloud computing infrastructure. The purpose of these recommendations is to provide guidelines against which all data providers can evaluate existing data systems and be used to improve any issues uncovered to enable efficient search, access, and use of large volumes of data. Additionally, these guidelines ensure that all cloud providers utilize a common methodology for bulk-downloading data from data providers thus preventing the data providers from building custom capabilities to meet the needs of individual cloud providers. The intent is to share these recommendations with other Federal agencies and organizations that serve Earth observation to enable efficient search, access, and use of large volumes of data. Additionally, the adoption of these recommendations will benefit data users interested in moving large volumes of data from data systems to any other location. These data users include the cloud providers, cloud users such as scientists, and other users working in a high performance computing environment who need to move large volumes of data.

  1. Measurement of maxillary sinus volume using Computed Tomography

    International Nuclear Information System (INIS)

    Park, Chang Hee; Kim, Kee Deog; Park, Chang Seo

    2000-01-01

    To propose a standard value for the maxillary sinus volume of a normal Korean adult by measuring the width and height of the sinus and analyzing their correlation and the difference of the sinus size respectively between sexes, and on the right and left sides. Fifty-two (95 maxillary sinuses) out of 20 years or over aged patients who had taken CT in the Department of Dental Radiology, Yonsei University, Dental Hospital, between February 1997 and July 1999 who were no specific symptom, prominent bony septa, pathosis, clinical asymmetry and history of surgery in the maxillary sinus were retrospectively analyzed. The mean transverse width, antero-posterior width, height and volume of the normal Korean adult's maxillary sinuses were 28.33 mm, 39.69 mm, 46.60 mm and 21.90 cm 3 , respectively. There was a significant sex difference in the sinus volume (p<0.05). In the mean antero-posterior width, height and volume of the sinus, no significant difference was observed between both sides. All four measurements showed a significant correlation between both sides (p<0.0001). The widths and height of the sinus all showed a significant correlation with the sinus volume (p<0.0001). In the Korean normal adult's maxillary sinus, males tended to be larger than females. Except for the transverse width, all of the measurements showed no significant difference between the right and left side, but significant correlations in the four measurements between both sides were observed. Thus, the overgrowth or undergrowth in the unilateral maxillary sinus may suggest a certain pathosis or developmental abnormalities in the maxillary sinus.

  2. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering

    KAUST Repository

    Sicat, Ronell Barrera

    2014-12-31

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined in the 4D domain jointly comprising the 3D volume and its 1D intensity range. Crucially, the computation of sparse pdf volumes exploits data coherence in 4D, resulting in a sparse representation with surprisingly low storage requirements. At run time, we dynamically apply transfer functions to the pdfs using simple and fast convolutions. Whereas standard low-pass filtering and down-sampling incur visible differences between resolution levels, the use of pdfs facilitates consistent results independent of the resolution level used. We describe the efficient out-of-core computation of large-scale sparse pdf volumes, using a novel iterative simplification procedure of a mixture of 4D Gaussians. Finally, our data structure is optimized to facilitate interactive multi-resolution volume rendering on GPUs.

  3. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering

    KAUST Repository

    Sicat, Ronell Barrera; Kruger, Jens; Moller, Torsten; Hadwiger, Markus

    2014-01-01

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined

  4. Volume-weighted measure for eternal inflation

    International Nuclear Information System (INIS)

    Winitzki, Sergei

    2008-01-01

    I propose a new volume-weighted probability measure for cosmological 'multiverse' scenarios involving eternal inflation. The 'reheating-volume (RV) cutoff' calculates the distribution of observable quantities on a portion of the reheating hypersurface that is conditioned to be finite. The RV measure is gauge-invariant, does not suffer from the 'youngness paradox', and is independent of initial conditions at the beginning of inflation. In slow-roll inflationary models with a scalar inflaton, the RV-regulated probability distributions can be obtained by solving nonlinear diffusion equations. I discuss possible applications of the new measure to 'landscape' scenarios with bubble nucleation. As an illustration, I compute the predictions of the RV measure in a simple toy landscape.

  5. Pressure Dependence of Molar Volume near the Melting Point in Benzene

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The pressure dependence of the molar volume was at constant temperatures close to the melting point in benzene. The molar volume of benzene was calculated using experimental data for the thermal expansivity for constant temperatures of 25℃, 28.5℃, 40℃, and 51℃ at various pressures for both the solid and liquid phases. The predictions are in good agreement with the observed volumes in both the solid and liquid phases of benzene. The predicted values of the molar volume for a constant temperature of 28.5℃ in the liquid phase of benzene agree well with experimental data in the literature.

  6. Volume-based characterization of postocclusion surge.

    Science.gov (United States)

    Zacharias, Jaime; Zacharias, Sergio

    2005-10-01

    To propose an alternative method to characterize postocclusion surge using a collapsible artificial anterior chamber to replace the currently used rigid anterior chamber model. Fundación Oftamológica Los Andes, Santiago, Chile. The distal end of a phacoemulsification handpiece was placed inside a compliant artificial anterior chamber. Digital recordings of chamber pressure, chamber volume, inflow, and outflow were performed during occlusion break of the phacoemulsification tip. The occlusion break profile of 2 different consoles was compared. Occlusion break while using a rigid anterior chamber model produced a simultaneous increase of chamber inflow and outflow. In the rigid chamber model, pressure decreased sharply, reaching negative pressure values. Alternatively, with the collapsible chamber model, a delay was observed in the inflow that occurs to compensate the outflow surge. Also, the chamber pressure drop was smaller in magnitude, never undershooting below atmospheric pressure into negative values. Using 500 mm Hg as vacuum limit, the Infiniti System (Alcon) performed better that the Legacy (Alcon), showing an 18% reduction in peak volume variation. The collapsible anterior chamber model provides a more realistic representation of the postocclusion surge events that occur in the real eye during cataract surgery. Peak volume fluctuation (mL), half volume recovery time(s), and volume fluctuation integral value (mL x s) are proposed as realistic indicators to characterize the postocclusion surge performance. These indicators show that the Infiniti System has a better postocclusion surge behavior than the Legacy System.

  7. Sonographic measurement of thyroid gland volume: A comparison of 2D and 3D ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Ying, Michael [Department of Optometry and Radiography, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)]. E-mail: ormying@polyu.edu.hk; Sin Manhong [Department of Optometry and Radiography, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); Pang, Shuk-fan [Department of Optometry and Radiography, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)

    2005-11-01

    Aims: This study was undertaken to investigate the inter-observer reproducibility of 2D and 3D ultrasound in the measurement of thyroid gland volume. The symmetry of thyroid lobes in healthy subjects was also investigated. Materials and methods: The volume of the left and right lobes of the thyroid gland was measured in 20 healthy subjects (10 men and 10 women) using 2D and 3D ultrasound. On 2D ultrasound, the thyroid lobe volume was calculated by ellipsoid equation (volume = {pi}/6 x craniocaudal x mediolateral x anteroposterior dimensions), whereas 3D ultrasound volumetric measurements were performed with a 3D add-on system. In each subject, the thyroid gland was scanned by two operators to investigate inter-observer variability. Results: There was a moderate agreement between 2D and 3D ultrasound in the measurement of thyroid volume (r = 0.77). 3D ultrasound (90%) had a higher inter-observer reproducibility than 2D ultrasound (85%) in the measurements. About 74% of healthy subjects had the right thyroid lobe larger than the left lobe. Conclusion: 3D ultrasound is useful in the measurement of thyroid volume with a higher reproducibility than 2D ultrasound. Asymmetry of thyroid lobes was noted in healthy subjects.

  8. Sonographic measurement of thyroid gland volume: A comparison of 2D and 3D ultrasound

    International Nuclear Information System (INIS)

    Ying, Michael; Sin Manhong; Pang, Shuk-fan

    2005-01-01

    Aims: This study was undertaken to investigate the inter-observer reproducibility of 2D and 3D ultrasound in the measurement of thyroid gland volume. The symmetry of thyroid lobes in healthy subjects was also investigated. Materials and methods: The volume of the left and right lobes of the thyroid gland was measured in 20 healthy subjects (10 men and 10 women) using 2D and 3D ultrasound. On 2D ultrasound, the thyroid lobe volume was calculated by ellipsoid equation (volume = π/6 x craniocaudal x mediolateral x anteroposterior dimensions), whereas 3D ultrasound volumetric measurements were performed with a 3D add-on system. In each subject, the thyroid gland was scanned by two operators to investigate inter-observer variability. Results: There was a moderate agreement between 2D and 3D ultrasound in the measurement of thyroid volume (r = 0.77). 3D ultrasound (90%) had a higher inter-observer reproducibility than 2D ultrasound (85%) in the measurements. About 74% of healthy subjects had the right thyroid lobe larger than the left lobe. Conclusion: 3D ultrasound is useful in the measurement of thyroid volume with a higher reproducibility than 2D ultrasound. Asymmetry of thyroid lobes was noted in healthy subjects

  9. Age, gender, and interracial variability of normal lacrimal gland volume using MRI.

    Science.gov (United States)

    Bukhari, Amal A; Basheer, Naushad A; Joharjy, Heba I

    2014-01-01

    Aimed to evaluate normal volume of the lacrimal gland in patients of different age groups and race. All MRI studies of the brain that were done between June 2012 and April 2013 were examined. Lacrimal glands were identified using fat-saturated fluid-attenuated inversion recovery (FLAIR) images, and the volumes were calculated using TeraRecon iNtuition viewer. Volumes for the right and left lacrimal glands were recorded for persons of different age groups and race, and the results were compared with those of a randomly selected group of patients who had undergone the same calculation method using CT of the brain, orbit, or paranasal sinuses. The authors included 998 lacrimal glands of 499 patients. The mean volumes for the right and left lacrimal glands were 0.770 and 0.684 cm, respectively. Lacrimal glands were larger in women; the largest volumes were observed during the second decade of life. Mean volumes also varied with race: 0.840 cm in Asians, 0.790 cm in Africans, 0.760 cm in Indians, and 0.710 cm in Middle Easterners. The consultant neuroradiologist and the intern showed excellent agreement for measurements of lacrimal gland volume. No significant difference was observed between lacrimal gland measurements method on MRI and CT. Lacrimal gland volume varies according to age, gender, race, and laterality. Measurements with MRI using fat-saturated FLAIR images and TeraRecon iNtuition viewer software are reliable, accurate, and can be used by junior staff with less radiation exposure to patients.

  10. Comparison of MRI pulse sequences in defining prostate volume after permanent implantation

    International Nuclear Information System (INIS)

    McLaughlin, P.W.; Narayana, V.; Drake, D.G.; Miller, B.M.; Marsh, L.; Chan, J.; Gonda, R.; Winfield, R.J.; Roberson, P.L.

    2002-01-01

    Purpose: To determine the relative value of three MRI pulse sequences in defining the prostate volume after permanent implantation. Methods and Materials: A total of 45 patients who received a permanent 125 I implant were studied. Two weeks after implantation, an axial CT scan (2 mm thickness) and T 1 -weighted, T 1 -weighted fat saturation, and T 2 -weighted axial MRI (3-mm) studies were obtained. The prostate volumes were compared with the initial ultrasound planning volumes, and subsequently the CT, T 1 -weighted, and T 1 -weighted fat saturation MRI volumes were compared with the T 2 -weighted volumes. Discrepancies in volume were evaluated by visual inspection of the registered axial images and the registration of axial volumes on the sagittal T 2 -weighted volumes. In a limited set of patients, pre- and postimplant CT and T 2 -weighted MRI studies were available for comparison to determine whether prostate volume changes after implant were dependent on the imaging modality. Results: T 1 -weighted and T 1 -weighted fat saturation MRI and CT prostate volumes were consistently larger than the T 2 -weighted MRI prostate volumes, with a volume on average 1.33 (SD 0.24) times the T 2 -weighted volume. This discrepancy was due to the superiority of T 2 -weighted MRI for prostate definition at the following critical interfaces: membranous urethra, apex, and anterior base-bladder and posterior base-seminal vesicle interfaces. The differences in prostate definition in the anterior base region suggest that the commonly reported underdose may be due to overestimation of the prostate in this region by CT. The consistent difference in volumes suggests that the degree of swelling observed after implantation is in part a function of the imaging modality. In patients with pre- and postimplant CT and T 2 -weighted MRI images, swelling on the T 2 -weighted images was 1.1 times baseline and on CT was 1.3 times baseline, confirming the imaging modality dependence of prostate

  11. Experimental heat capacity of solid hydrogen as a function of molar volume

    International Nuclear Information System (INIS)

    Krause, J.K.

    1978-01-01

    Constant volume heat capacity measurements have been made on six solid hydrogen samples with low orthohydrogen concentrations. The measurements extend from approximately 1.5 K to the melting line, with molar volumes ranging from 22.787 cm 3 /mole to 16.193 cm 3 /mole. Although clustering of the ortho molecules was observed, the low temperature heat capacity anomaly due to the orthohydrogen pairs could be described quite well by the assumption of a fixed distribution. The data were corrected to obtain a lattice heat capacity which on extrapolation to T = 0 yielded Debye temperatures and a volume dependent Grueneisen parameter. A modified Mie-Grueneisen approximation was used to define a volume and temperature dependent Grueneisen parameter which was used to calculate the equation of state, P(V,T), and isothermal bulk modulus, B/sub T/(V,T), for the six isochores. An extrapolation of the equation of state to T = 0 and P = 0 by two different methods yields a molar volume which, when compared with other determinations, gives a recommended value of 23.20 +- 0.05 cm 3 /mole. A rapid increase in the conversion rate of orthohydrogen to parahydrogen was observed at approximately theta/sub o/12. The molar volumes along the melting curve also have been determined directly for the first time in this volume range. These results have been used to show that a low temperature Lindemann melting relation is only approximately valid for solid hydrogen to 50 K

  12. A consensus-based dynamics for market volumes

    Science.gov (United States)

    Sabatelli, Lorenzo; Richmond, Peter

    2004-12-01

    We develop a model of trading orders based on opinion dynamics. The agents may be thought as the share holders of a major mutual fund rather than as direct traders. The balance between their buy and sell orders determines the size of the fund order (volume) and has an impact on prices and indexes. We assume agents interact simultaneously to each other through a Sznajd-like interaction. Their degree of connection is determined by the probability of changing opinion independently of what their neighbours are doing. We assume that such a probability may change randomly, after each transaction, of an amount proportional to the relative difference between the volatility then measured and a benchmark that we assume to be an exponential moving average of the past volume values. We show how this simple model is compatible with some of the main statistical features observed for the asset volumes in financial markets.

  13. A general methodology for three-dimensional analysis of variation in target volume delineation

    NARCIS (Netherlands)

    Remeijer, P.; Rasch, C.; Lebesque, J. V.; van Herk, M.

    1999-01-01

    A generic method for three-dimensional (3-D) evaluation of target volume delineation in multiple imaging modalities is presented. The evaluation includes geometrical and statistical methods to estimate observer differences and variability in defining the Gross Tumor Volume (GTV) in relation to the

  14. Free volume sizes in intercalated polyamide 6/clay nanocomposites

    DEFF Research Database (Denmark)

    Wiinberg, P.; Eldrup, Morten Mostgaard; Pedersen, N.J.

    2005-01-01

    The effect of incorporating modified clay into a polyamide 6 (PA6) matrix, on the free volume cavity sizes and the thermal and viscoelastic properties of the resulting nanocomposite, was studied with positron annihilation lifetime spectroscopy, differential scanning calorimetry and dynamic...... response of PA6/clay nanocomposites, as compared to unfilled PA6, pointed towards a changed mobility in the non-crystalline regions. At high concentrations of clay (> 19 wt%) an increase of the free volume cavity diameter was observed, indicating a lower chain packing efficiency in the PA6/clay...... nanocomposites. The increased free volume sizes were present both above and below the glass transition temperature of PA6. (c) 2005 Elsevier Ltd. All rights reserved....

  15. Residual limb fluid volume change and volume accommodation: Relationships to activity and self-report outcomes in people with trans-tibial amputation.

    Science.gov (United States)

    Sanders, Joan E; Youngblood, Robert T; Hafner, Brian J; Ciol, Marcia A; Allyn, Katheryn J; Gardner, David; Cagle, John C; Redd, Christian B; Dietrich, Colin R

    2018-02-01

    Fluctuations in limb volume degrade prosthesis fit and require users to accommodate changes using management strategies, such as donning and doffing prosthetic socks. To examine how activities and self-report outcomes relate to daily changes in residual limb fluid volume and volume accommodation. Standardized, two-part laboratory protocol with an interim observational period. Participants were classified as "accommodators" or "non-accommodators," based on self-report prosthetic sock use. Participants' residual limb fluid volume change was measured using a custom bioimpedance analyzer and a standardized in-laboratory activity protocol. Self-report health outcomes were assessed with the Socket Comfort Score and Prosthesis Evaluation Questionnaire. Activity was monitored while participants left the laboratory for at least 3 h. They then returned to repeat the bioimpedance test protocol. Twenty-nine people were enrolled. Morning-to-afternoon percent limb fluid volume change per hour was not strongly correlated to percent time weight-bearing or to self-report outcomes. As a group, non-accommodators ( n = 15) spent more time with their prosthesis doffed and reported better outcomes than accommodators. Factors other than time weight-bearing may contribute to morning-to-afternoon limb fluid volume changes and reported satisfaction with the prosthesis among trans-tibial prosthesis users. Temporary doffing may be a more effective and satisfying accommodation method than sock addition. Clinical relevance Practitioners should be mindful that daily limb fluid volume change and prosthesis satisfaction are not dictated exclusively by activity. Temporarily doffing the prosthesis may slow daily limb fluid volume loss and should be investigated as an alternative strategy to sock addition.

  16. Intra- and interobserver variability of thyroid volume measurements in healthy adults by 2D versus 3D ultrasound

    International Nuclear Information System (INIS)

    Andermann, P.; Schloegl, S.; Maeder, U.; Luster, M.; Lassmann, M.; Reiners, C.

    2007-01-01

    Thyroid volume measurement by ultrasonography (US) is essential in numerous clinical diagnostic and therapeutic fields. While known to be limited, the accuracy and precision of two-dimensional (2D) US thyroid volume measurement have not been thoroughly characterized. Objective: We sought to assess the intra- and interobserver variability, accuracy and precision of thyroid volume determination by conventional 2D US in healthy adults using reference volumes determined by three-dimensional (3D) US. Design, methods: In a prospective blinded trial, thyroid volumes of ten volunteers were determined repeatedly by nine experienced sonographers using conventional 2D US (ellipsoid model). The values obtained were statistically compared to the so-called true volumes determined by 3D US (multiplanar approximation), the so-called gold standard, to estimate systematic errors and relative deviations of individual observers. Results: The standard error of measurement (SEM) for one observer and successive measurements (intraobserver variability), was 14%, and for different observers and repeated measurements (interobserver variability), 17%. The minimum relative thyroid volume change significantly different at the 95% level was 39% for the same observer and 46% for different observers. Regarding accuracy, the mean value of the differences showed a significant thyroid volume overestimation (17%, p <0.01) by 2D relative to 3D US. Conclusion: 2D US is appropriate for routine thyroid volumetry. Nevertheless, the so-called human factor (random error) should be kept in mind and correction is needed for methodical bias (systematic error). Further efforts are required to improve the accuracy and precision of 2D US thyroid volumetry by optimizing the underlying geometrical modeling or by the application of 3D US. (orig.)

  17. Pituitary gland volume and psychosocial stress among children at elevated risk for schizophrenia.

    Science.gov (United States)

    Cullen, A E; Day, F L; Roberts, R E; Pariante, C M; Laurens, K R

    2015-11-01

    Pituitary volume enlargements have been observed among individuals with first-episode psychosis. These abnormalities are suggestive of hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, which may contribute to the development of psychosis. However, the extent to which these abnormalities characterize individuals at elevated risk for schizophrenia prior to illness onset is currently unclear, as volume increases, decreases and no volume differences have all been reported relative to controls. The current study aimed to determine whether antipsychotic-naive, putatively at-risk children who present multiple antecedents of schizophrenia (ASz) or a family history of illness (FHx) show pituitary volume abnormalities relative to typically developing (TD) children. An additional aim was to explore the association between pituitary volume and experiences of psychosocial stress. ASz (n = 30), FHx (n = 22) and TD (n = 32) children were identified at age 9-12 years using a novel community-screening procedure or as relatives of individuals with schizophrenia. Measures of pituitary volume and psychosocial stress were obtained at age 11-14 years. Neither ASz nor FHx children showed differences in pituitary volume relative to TD children. Among FHx children only, pituitary volume was negatively associated with current distress relating to negative life events and exposure to physical punishment. The lack of pituitary volume abnormalities among ASz and FHx children is consistent with our previous work demonstrating that these children are not characterized by elevated diurnal cortisol levels. The findings imply that these biological markers of HPA axis hyperactivity, observed in some older samples of high-risk individuals, may emerge later, more proximally to disease onset.

  18. The Voronoi volume and molecular representation of molar volume: equilibrium simple fluids.

    Science.gov (United States)

    Hunjan, Jagtar Singh; Eu, Byung Chan

    2010-04-07

    The Voronoi volume of simple fluids was previously made use of in connection with volume transport phenomena in nonequilibrium simple fluids. To investigate volume transport phenomena, it is important to develop a method to compute the Voronoi volume of fluids in nonequilibrium. In this work, as a first step to this goal, we investigate the equilibrium limit of the nonequilibrium Voronoi volume together with its attendant related molar (molal) and specific volumes. It is proved that the equilibrium Voronoi volume is equivalent to the molar (molal) volume. The latter, in turn, is proved equivalent to the specific volume. This chain of equivalences provides an alternative procedure of computing the equilibrium Voronoi volume from the molar volume/specific volume. We also show approximate methods of computing the Voronoi and molar volumes from the information on the pair correlation function. These methods may be employed for their quick estimation, but also provide some aspects of the fluid structure and its relation to the Voronoi volume. The Voronoi volume obtained from computer simulations is fitted to a function of temperature and pressure in the region above the triple point but below the critical point. Since the fitting function is given in terms of reduced variables for the Lennard-Jones (LJ) model and the kindred volumes (i.e., specific and molar volumes) are in essence equivalent to the equation of state, the formula obtained is a reduced equation state for simple fluids obeying the LJ model potential in the range of temperature and pressure examined and hence can be used for other simple fluids.

  19. Inter- and Intra-Observer Variability in Prostate Definition With Tissue Harmonic and Brightness Mode Imaging

    International Nuclear Information System (INIS)

    Sandhu, Gurpreet Kaur; Dunscombe, Peter; Meyer, Tyler; Pavamani, Simon; Khan, Rao

    2012-01-01

    Purpose: The objective of this study was to compare the relative utility of tissue harmonic (H) and brightness (B) transrectal ultrasound (TRUS) images of the prostate by studying interobserver and intraobserver variation in prostate delineation. Methods and Materials: Ten patients with early-stage disease were randomly selected. TRUS images of prostates were acquired using B and H modes. The prostates on all images were contoured by an experienced radiation oncologist (RO) and five equally trained observers. The observers were blinded to information regarding patient and imaging mode. The volumes of prostate glands and areas of midgland slices were calculated. Volumes contoured were compared among the observers and between observer group and RO. Contours on one patient were repeated five times by four observers to evaluate the intraobserver variability. Results: A one-sample Student t-test showed the volumes outlined by five observers are in agreement (p > 0.05) with the RO. Paired Student t-test showed prostate volumes (p = 0.008) and midgland areas (p = 0.006) with H mode were significantly smaller than that with B mode. Two-factor analysis of variances showed significant interobserver variability (p < 0.001) in prostate volumes and areas. Inter- and intraobserver consistency was quantified as the standard deviation of mean volumes and areas, and concordance indices. It was found that for small glands (≤35 cc) H mode provided greater interobserver consistency; however, for large glands (≥35 cc), B mode provided more consistent estimates. Conclusions: H mode provided superior inter- and intraobserver agreement in prostate volume definition for small to medium prostates. In large glands, H mode does not exhibit any additional advantage. Although harmonic imaging has not proven advantageous for all cases, its utilization seems to be judicious for small prostates.

  20. MODEL PERUBAHAN VOLUME KERIPIK BUAH SELAMA PROSES PENGGORENGAN SECARA VAKUM [Model for Volume Changes in Fruit Chips during Vacuum Frying

    Directory of Open Access Journals (Sweden)

    Jamaluddin1*

    2011-06-01

    Full Text Available Expansion and puffing are specific characteristics of fried products critical for consumer preferences. To obtain expanded and puffed dried products that fit well with consumer acceptance criteria, it is necessary to pay attention to the process conditions which change the raw material characteristics during frying. The important changes include volume and density ratio of the products during frying. Hypothetically, these changes are due to water vaporization and the decrease dry matter in the products. The objective of this research is to develop a mathematical model of volume and density ratio changes for jack fruit during vacuum frying as a function of water and starch content reductions. Samples were vacuum fried at 70–100OC and pressure of 80-90 kPa for 15–60 min. The parameters observed were volume and density as well as water and starch contents of samples before and after vacuum frying. The results showed that the developed model can be used to predict changes in volume and density ratio of jack fruit during vacuum frying.

  1. Effect of high-volume systematic local infiltration analgesia in Caesarean section

    DEFF Research Database (Denmark)

    Larsen, Klaus Richter; Kristensen, B B; Rasmussen, M A

    2015-01-01

    BACKGROUND: Pain after Caesarean section is often treated with opioids with a risk of side effects. Wound infiltration with local anaesthetics is effective and has few side effects, but volume vs. dose concentration has not been examined. METHODS: Ninety patients scheduled for elective Caesarean...... found concerning time spent in the PACU, to first mobilisation or in number of women with nausea/vomiting (P ≥ 0.05). No complications related to ropivacaine were observed. CONCLUSIONS: Systematic infiltration with a high concentration, low volume compared with low concentration, high volume showed...

  2. [Evaluation of tidal volume delivered by ventilators during volume-controlled ventilation].

    Science.gov (United States)

    Zhou, Juan; Yan, Yong; Cao, Desen

    2014-12-01

    To study the ways which ensure the delivery of enough tidal volume to patients under various conditions close to the demand of the physician. The volume control ventilation model was chosen, and the simulation lung type was active servo lung ASL 5000 or Michigan lung 1601. The air resistance, air compliance and lung type in simulation lungs were set. The tidal volume was obtained from flow analyzer PF 300. At the same tidal volume, the displaying values of tidal volume of E5, Servo i, Evital 4, and Evital XL ventilators with different lung types of patient, compliance of gas piping, leakage, gas types, etc. were evaluated. With the same setting tidal volume of a same ventilator, the tidal volume delivered to patients was different with different lung types of patient, compliance of gas piping, leakage, gas types, etc. Reducing compliance and increasing resistance of the patient lungs caused high peak airway pressure, the tidal volume was lost in gas piping, and the tidal volume be delivered to the patient lungs was decreased. If the ventilator did not compensate to leakage, the tidal volume delivered to the patient lungs was decreased. When the setting gas type of ventilator did not coincide with that applying to the patient, the tidal volume be delivered to the patient lungs might be different with the setting tidal volume of ventilator. To ensure the delivery of enough tidal volume to patients close to the demand of the physician, containable factors such as the compliance of gas piping, leakage, and gas types should be controlled.

  3. Bounding uncertainty in volumetric geometric models for terrestrial lidar observations of ecosystems.

    Science.gov (United States)

    Paynter, Ian; Genest, Daniel; Peri, Francesco; Schaaf, Crystal

    2018-04-06

    Volumetric models with known biases are shown to provide bounds for the uncertainty in estimations of volume for ecologically interesting objects, observed with a terrestrial laser scanner (TLS) instrument. Bounding cuboids, three-dimensional convex hull polygons, voxels, the Outer Hull Model and Square Based Columns (SBCs) are considered for their ability to estimate the volume of temperate and tropical trees, as well as geomorphological features such as bluffs and saltmarsh creeks. For temperate trees, supplementary geometric models are evaluated for their ability to bound the uncertainty in cylinder-based reconstructions, finding that coarser volumetric methods do not currently constrain volume meaningfully, but may be helpful with further refinement, or in hybridized models. Three-dimensional convex hull polygons consistently overestimate object volume, and SBCs consistently underestimate volume. Voxel estimations vary in their bias, due to the point density of the TLS data, and occlusion, particularly in trees. The response of the models to parametrization is analysed, observing unexpected trends in the SBC estimates for the drumlin dataset. Establishing that this result is due to the resolution of the TLS observations being insufficient to support the resolution of the geometric model, it is suggested that geometric models with predictable outcomes can also highlight data quality issues when they produce illogical results.

  4. Comparison of polyp size and volume at CT colonography: implications for follow-up CT colonography.

    Science.gov (United States)

    Bethea, Emily; Nwawka, Ogonna K; Dachman, Abraham H

    2009-12-01

    The purpose of this study was to evaluate the reliability of polyp measurements at CT colonography and the factors that affect the measurements. Fifty colonoscopically proven cases of polyps 6 mm in diameter or larger were analyzed by two observers who measured each polyp in supine and prone views. Manual measurements of 2D volume by summation of areas, 2D maximum diameter, and 3D maximum diameter and automated measurements of 3D maximum diameter and volume were recorded for each observer and were repeated for one of the observers. Intraobserver and interobserver agreement was calculated. Analysis was performed to determine the measurement parameter that correlated most with summation-of-areas volume. Supine and prone measurements as a surrogate for tracking change in polyp size over time were analyzed to determine the measurement parameter with the least variation. Maximum diameter measured manually on 3D images had the highest correlation with summation-of-areas volume. Manual summation-of-areas volume was found to have the least variation between supine and prone measurements. Linear polyp measurement in the 3D endoluminal view appears to be the most reliable parameter for use in the decision to excise a polyp according to current guidelines. In our study, manual calculation of volume with summation of areas was found to be the most reliable measurement parameter for observing polyp growth over serial examinations. High reliability of polyp measurements is essential for adequate assessment of change in polyp size over serial examinations because many patients with intermediate-size polyps are expected to choose surveillance.

  5. Clinical Relevance of Brain Volume Measures in Multiple Sclerosis

    DEFF Research Database (Denmark)

    De Stefano, Nicola; Airas, Laura; Grigoriadis, Nikolaos

    2014-01-01

    Multiple sclerosis (MS) is a chronic disease with an inflammatory and neurodegenerative pathology. Axonal loss and neurodegeneration occurs early in the disease course and may lead to irreversible neurological impairment. Changes in brain volume, observed from the earliest stage of MS...... therefore have important clinical implications affecting treatment decisions, with several clinical trials now demonstrating an effect of disease-modifying treatments (DMTs) on reducing brain volume loss. In clinical practice, it may therefore be important to consider the potential impact of a therapy...

  6. Volume and Surface-Enhanced Volume Negative Ion Sources

    International Nuclear Information System (INIS)

    Stockli, M P

    2013-01-01

    H - volume sources and, especially, caesiated H - volume sources are important ion sources for generating high-intensity proton beams, which then in turn generate large quantities of other particles. This chapter discusses the physics and technology of the volume production and the caesium-enhanced (surface) production of H - ions. Starting with Bacal's discovery of the H - volume production, the chapter briefly recounts the development of some H - sources, which capitalized on this process to significantly increase the production of H - beams. Another significant increase was achieved in the 1990s by adding caesiated surfaces to supplement the volume-produced ions with surface-produced ions, as illustrated with other H - sources. Finally, the focus turns to some of the experience gained when such a source was successfully ramped up in H - output and in duty factor to support the generation of 1 MW proton beams for the Spallation Neutron Source. (author)

  7. Observations of joint persistence and connectivity across boreholes

    Energy Technology Data Exchange (ETDEWEB)

    Thapa, B.B.; Karasaki, K.

    1996-01-01

    Observations of joint persistence and connectivity are made by comparison of digital borehole wall images of fractures, fluid conductivity logs and hydraulic injections test results. The fractures were found to be generally impersistent across vertical boreholes about 8 m apart. Many hydraulic connections were found in the same volume of rock. Direct connections through single fractures seem to be rare and connectivity appears to be controlled by fracture networks, even over small volumes.

  8. Development of Automatic Visceral Fat Volume Calculation Software for CT Volume Data

    Directory of Open Access Journals (Sweden)

    Mitsutaka Nemoto

    2014-01-01

    Full Text Available Objective. To develop automatic visceral fat volume calculation software for computed tomography (CT volume data and to evaluate its feasibility. Methods. A total of 24 sets of whole-body CT volume data and anthropometric measurements were obtained, with three sets for each of four BMI categories (under 20, 20 to 25, 25 to 30, and over 30 in both sexes. True visceral fat volumes were defined on the basis of manual segmentation of the whole-body CT volume data by an experienced radiologist. Software to automatically calculate visceral fat volumes was developed using a region segmentation technique based on morphological analysis with CT value threshold. Automatically calculated visceral fat volumes were evaluated in terms of the correlation coefficient with the true volumes and the error relative to the true volume. Results. Automatic visceral fat volume calculation results of all 24 data sets were obtained successfully and the average calculation time was 252.7 seconds/case. The correlation coefficients between the true visceral fat volume and the automatically calculated visceral fat volume were over 0.999. Conclusions. The newly developed software is feasible for calculating visceral fat volumes in a reasonable time and was proved to have high accuracy.

  9. Effects of gauge volume on pseudo-strain induced in strain measurement using time-of-flight neutron diffraction

    International Nuclear Information System (INIS)

    Suzuki, Hiroshi; Harjo, Stefanus; Abe, Jun; Xu, Pingguang; Aizawa, Kazuya; Akita, Koichi

    2013-01-01

    Spurious or pseudo-strains observed in time-of-flight (TOF) neutron diffraction due to neutron attenuation, surface-effects and a strain distribution within the gauge volume were investigated. Experiments were carried out on annealed and bent ferritic steel bars to test these effects. The most representative position in the gauge volume corresponds to the neutron-weighted center of gravity (ncog), which takes into account variations in intensity within the gauge volume due to neutron attenuation and/or absence of material in the gauge volume. The average strain in the gauge volume was observed to be weighted towards the ncog position but following an increase in the size of the gauge volume the weighted average strain was changed because of the change in the ncog position when a strain gradient appeared within the gauge volume. On the other hand, typical pseudo-strains, which are well known, did appear in through-surface strain measurements when the gauge volume was incompletely filled by the sample. Tensile pseudo-strains due to the surface-effect increased near the sample surface and exhibited a similar trend regardless of the size of the gauge volume, while the pseudo-strains increased faster for the smaller gauge volume. Furthermore, a pseudo-strain due to a change in the ncog position was observed even when the gauge volume was perfectly filled in the sample, and it increased with an increase in the size of the gauge volume. These pseudo-strains measured were much larger than those simulated by the conventional modeling, whereas they were simulated by taking into account an incident neutron beam divergence additionally in the model. Therefore, the incident divergence of the incident neutron beam must be carefully designed to avoid pseudo-strains in time-of-flight neutron diffractometry

  10. Seasonal variations in the volume of the haemolymph and body weight of the horseshoe crab, Tachypleus gigas (Muller)

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Rathod, V.; Parulekar, A.H.

    in sizes between 121-140 mm. An inverse relationship was observed between the volume of haemolymph and salinity of the environment. Maximum volume of haemolymph (57.3 ml) in females was observed when the salinity of the environment was low in October...

  11. Change in brain and lesion volumes after CEE therapies

    Science.gov (United States)

    Espeland, Mark A.; Hogan, Patricia E.; Resnick, Susan M.; Bryan, R. Nick; Robinson, Jennifer G.; Goveas, Joseph S.; Davatzikos, Christos; Kuller, Lewis H.; Williamson, Jeff D.; Bushnell, Cheryl D.; Shumaker, Sally A.

    2014-01-01

    Objectives: To determine whether smaller brain volumes in older women who had completed Women's Health Initiative (WHI)-assigned conjugated equine estrogen–based hormone therapy (HT), reported by WHI Memory Study (WHIMS)-MRI, correspond to a continuing increased rate of atrophy an average of 6.1 to 7.7 years later in WHIMS-MRI2. Methods: A total of 1,230 WHI participants were contacted: 797 (64.8%) consented, and 729 (59%) were rescanned an average of 4.7 years after the initial MRI scan. Mean annual rates of change in total brain volume, the primary outcome, and rates of change in ischemic lesion volumes, the secondary outcome, were compared between treatment groups using mixed-effect models with adjustment for trial, clinical site, age, intracranial volumes, and time between MRI measures. Results: Total brain volume decreased an average of 3.22 cm3/y in the active arm and 3.07 cm3/y in the placebo arm (p = 0.53). Total ischemic lesion volumes increased in both arms at a rate of 0.12 cm3/y (p = 0.88). Conclusions: Conjugated equine estrogen–based postmenopausal HT, previously assigned at WHI baseline, did not affect rates of decline in brain volumes or increases in brain lesion volumes during the 4.7 years between the initial and follow-up WHIMS-MRI studies. Smaller frontal lobe volumes were observed as persistent group differences among women assigned to active HT compared with placebo. Women with a history of cardiovascular disease treated with active HT, compared with placebo, had higher rates of accumulation in white matter lesion volume and total brain lesion volume. Further study may elucidate mechanisms that explain these findings. PMID:24384646

  12. Volume of sealer in the apical region of teeth filled by different techniques: a micro-CT analysis

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Vanessa Lessa; Souza-Gabriel, Aline Evangelista; Cruz Filho, Antonio Miranda da; Pecora, Jesus Djalma; Silva, Ricardo Gariba, E-mail: vanessalessa@usp.br [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Escola de Odontologia. Departamento de Odontologia Restauradora

    2016-05-01

    The volume of sealer in the apical 1 mm of teeth filled using different techniques was evaluated by micro-commuted tomography (micro-CT). Sixty-four maxillary central incisors were prepared using NiTi rotary instruments. Teeth were randomly distributed into four groups according to root canal sealers (AH Plus, Endofill, Sealapex, and Sealer 26) and subdivided into two subgroups according to the filling techniques (active and passive lateral condensation; n = 8 each). Subsequently, teeth were examined using the 1174 SkyScan micro-CT device. Images were reconstructed using the NRecon software, and the sealer volume (mm{sup 3}) in the apical region was analyzed using the two-way ANOVA and post-hoc Student-Newman-Keuls test (α = 0.05). The lowest volume of sealer was observed in teeth filled with Sealapex (0.100 ± 0.009) and Endofill (0.103 ± 0.010). The highest volume was observed in teeth filled with AH Plus (0.112 ± 0.008) and Sealer 26 (0.109 ± 0.018) (p > 0.05). Regarding the filling technique, a lower sealer volume was observed using the active lateral condensation technique compared with that using the passive lateral condensation technique (0.100 ± 0.010 vs. 0.111 ± 0.012) (p < 0.05). Therefore, the lowest volume of sealer was observed in teeth filled with Sealapex and Endofill using the active lateral condensation technique. (author)

  13. Volume of sealer in the apical region of teeth filled by different techniques: a micro-CT analysis

    International Nuclear Information System (INIS)

    Araujo, Vanessa Lessa; Souza-Gabriel, Aline Evangelista; Cruz Filho, Antonio Miranda da; Pecora, Jesus Djalma; Silva, Ricardo Gariba

    2016-01-01

    The volume of sealer in the apical 1 mm of teeth filled using different techniques was evaluated by micro-commuted tomography (micro-CT). Sixty-four maxillary central incisors were prepared using NiTi rotary instruments. Teeth were randomly distributed into four groups according to root canal sealers (AH Plus, Endofill, Sealapex, and Sealer 26) and subdivided into two subgroups according to the filling techniques (active and passive lateral condensation; n = 8 each). Subsequently, teeth were examined using the 1174 SkyScan micro-CT device. Images were reconstructed using the NRecon software, and the sealer volume (mm 3 ) in the apical region was analyzed using the two-way ANOVA and post-hoc Student-Newman-Keuls test (α = 0.05). The lowest volume of sealer was observed in teeth filled with Sealapex (0.100 ± 0.009) and Endofill (0.103 ± 0.010). The highest volume was observed in teeth filled with AH Plus (0.112 ± 0.008) and Sealer 26 (0.109 ± 0.018) (p > 0.05). Regarding the filling technique, a lower sealer volume was observed using the active lateral condensation technique compared with that using the passive lateral condensation technique (0.100 ± 0.010 vs. 0.111 ± 0.012) (p < 0.05). Therefore, the lowest volume of sealer was observed in teeth filled with Sealapex and Endofill using the active lateral condensation technique. (author)

  14. Plasma volume, osmolality, vasopressin, and renin activity during graded exercise in man

    Science.gov (United States)

    Convertino, V. A.; Keil, L. C.; Bernauer, E. M.; Greenleaf, J. E.

    1981-01-01

    The influence of work intensity on plasma volume, osmolality, vasopressin and renin activity and the interrelationships between these responses are investigated. Plasma volume, renin activity and osmotic, sodium and arginine vasopressin concentrations were measured in venous blood samples taken from 15 healthy male subjects before and after six minutes of bicycle ergometer exercise at 100, 175 and 225 W. Plasma volume is found to decrease significantly with increasing work intensity, while increases in Na(+) concentration, osmolality and vasopressin are only observed to be significant when the work intensity exceeds 40% maximal aerobic capacity and plasma resin activity increased linearly at all work levels. In addition, significant correlations are observed between plasma volume and osmolality and sodium changes, and between vasopressin and osmolality and sodium content changes. Data thus support the hypotheses that (1) vasopressin may be the primary controlling endocrine for fluid and electrolyte levels following exercise; (2) an exercise intensity greater than 40% maximal aerobic capacity is required to stimulate vasopressin release through changes in plasma osmolality; and (3) the stimulation of the renin-angiotensin system is a more general stress response.

  15. Reduced frontal brain volume in non-treatment-seeking cocaine-dependent individuals: exploring the role of impulsivity, depression, and smoking.

    Science.gov (United States)

    Crunelle, Cleo L; Kaag, Anne Marije; van Wingen, Guido; van den Munkhof, Hanna E; Homberg, Judith R; Reneman, Liesbeth; van den Brink, Wim

    2014-01-01

    In cocaine-dependent patients, gray matter (GM) volume reductions have been observed in the frontal lobes that are associated with the duration of cocaine use. Studies are mostly restricted to treatment-seekers and studies in non-treatment-seeking cocaine abusers are sparse. Here, we assessed GM volume differences between 30 non-treatment-seeking cocaine-dependent individuals and 33 non-drug using controls using voxel-based morphometry. Additionally, within the group of non-treatment-seeking cocaine-dependent individuals, we explored the role of frequently co-occurring features such as trait impulsivity (Barratt Impulsivity Scale, BIS), smoking, and depressive symptoms (Beck Depression Inventory), as well as the role of cocaine use duration, on frontal GM volume. Smaller GM volumes in non-treatment-seeking cocaine-dependent individuals were observed in the left middle frontal gyrus. Moreover, within the group of cocaine users, trait impulsivity was associated with reduced GM volume in the right orbitofrontal cortex, the left precentral gyrus, and the right superior frontal gyrus, whereas no effect of smoking severity, depressive symptoms, or duration of cocaine use was observed on regional GM volumes. Our data show an important association between trait impulsivity and frontal GM volumes in cocaine-dependent individuals. In contrast to previous studies with treatment-seeking cocaine-dependent patients, no significant effects of smoking severity, depressive symptoms, or duration of cocaine use on frontal GM volume were observed. Reduced frontal GM volumes in non-treatment-seeking cocaine-dependent subjects are associated with trait impulsivity and are not associated with co-occurring nicotine dependence or depression.

  16. Comparison of different volume markers in peritoneal dialysis

    International Nuclear Information System (INIS)

    De Paepe, M.; Belpaire, F.; Schelstraete, K.; Lameire, N.

    1988-01-01

    Four peritoneal volume markers (carbon 14 -labeled dextran, dextran blue, radioactive albumin, and hemoglobin) were compared. In six rabbits 14 C-dextran was compared with dextran blue during a 4-hour dwell with a 4.25% dextrose solution. The recovery of 14 C-dextran at the end of the dwell was 71% +/- 3% vs. 92% +/- 1% for dextran blue (P less than 0.001). In six other rabbits, radioactive albumin (RISA) was compared with dextran blue. The recovery of RISA was 78% +/- 4%, compared with 85% +/- 2% for dextran blue (P less than 0.05). The calculated peritoneal volumes, uncorrected for disappearance of the markers, were consistently higher than when correction was made. After correction, the calculated end volumes were similar to actually measured end volumes. In six patients with chronic ambulatory peritoneal dialysis, the intraperitoneal volume during a single dwell of 6 hours was estimated in paired observations with lactated Ringer's solution and 1.5% dextrose dialysate, using simultaneously autologous hemoglobin and RISA. In eight additional patients, a single dwell with 4.25% dextrose dialysate was studied. The recoveries of both markers were related to the osmotic strength of the dialysate. Recoveries were 66.7% +/- 2.3% and 69.6% +/- 0.9% in lactated Ringer's solution, and increased to 81% +/- 3% and 82% +/- 2% in 4.25% dextrose for hemoglobin and RISA, respectively. With each dialysate, after correction for disappearance of the marker, no differences in volume profiles or between calculated or measured end volumes could be found with either hemoglobin or RISA

  17. Influence of sex and age on fasting and post-prandial gallbladder volumes

    International Nuclear Information System (INIS)

    Pazzi, P.; Putinati, S.; Barbieri, D.; Trevisani, L.; Limoni, G.; Lupi, L.; Bighi, S.

    1989-01-01

    Aging and female sex are major risk factors for cholesterol gallstones: in addition to hepatic secretion of lithogenic bile, decreased gallbladder contractility may play a role in such physiological conditions. This study was aimed at evaluating the effect of age and sex on gallbladder kinetics in healthy subjects. Gallbladder volume was measured on the US images of 157 fasting subjects using the sum-of-cylinders method. No significant difference was observed between males and females. On the contrary, age was shown to have a significant positive correlation with fasting gallbladder volume, particulary in males. In a second group of 63 healthy volunteers gallbladder volumes were evaluated both before and after a standard meal. The subjects were grouped according to age, and fasting gallbladder volume appeared to be significantly greater in the groups formed by older people. Gallbladder volumes were compared in younger groups (under 35), and gallbladder emptying resulted to be much more complete in males than in females. On the contrary, no significant differences was observed between males and famales over50 - which suggests a possible role of sex - and age-related hormonal factors. The above changes in gallbladder function may facilitate bile stasis which might in turn contribute to the increased risk for cholesterol gallstones notoriously associated with advanced age and female sex

  18. Knowledge-based reconstruction for measurement of right ventricular volumes on cardiovascular magnetic resonance images in a mixed population.

    Science.gov (United States)

    Pieterman, Elise D; Budde, Ricardo P J; Robbers-Visser, Daniëlle; van Domburg, Ron T; Helbing, Willem A

    2017-09-01

    Follow-up of right ventricular performance is important for patients with congenital heart disease. Cardiac magnetic resonance imaging is optimal for this purpose. However, observer-dependency of manual analysis of right ventricular volumes limit its use. Knowledge-based reconstruction is a new semiautomatic analysis tool that uses a database including knowledge of right ventricular shape in various congenital heart diseases. We evaluated whether knowledge-based reconstruction is a good alternative for conventional analysis. To assess the inter- and intra-observer variability and agreement of knowledge-based versus conventional analysis of magnetic resonance right ventricular volumes, analysis was done by two observers in a mixed group of 22 patients with congenital heart disease affecting right ventricular loading conditions (dextro-transposition of the great arteries and right ventricle to pulmonary artery conduit) and a group of 17 healthy children. We used Bland-Altman analysis and coefficient of variation. Comparison between the conventional method and the knowledge-based method showed a systematically higher volume for the latter group. We found an overestimation for end-diastolic volume (bias -40 ± 24 mL, r = .956), end-systolic volume (bias -34 ± 24 mL, r = .943), stroke volume (bias -6 ± 17 mL, r = .735) and an underestimation of ejection fraction (bias 7 ± 7%, r = .671) by knowledge-based reconstruction. The intra-observer variability of knowledge-based reconstruction varied with a coefficient of variation of 9% for end-diastolic volume and 22% for stroke volume. The same trend was noted for inter-observer variability. A systematic difference (overestimation) was noted for right ventricular size as assessed with knowledge-based reconstruction compared with conventional methods for analysis. Observer variability for the new method was comparable to what has been reported for the right ventricle in children and congenital

  19. Inter-observer variability in contouring the penile bulb on CT images for prostate cancer treatment planning

    International Nuclear Information System (INIS)

    Perna, Lucia; Cozzarini, Cesare; Maggiulli, Eleonora; Fellin, Gianni; Rancati, Tiziana; Valdagni, Riccardo; Vavassori, Vittorio; Villa, Sergio; Fiorino, Claudio

    2011-01-01

    Several investigations have recently suggested the existence of a correlation between the dose received by the penile bulb (PB) and the risk of erectile dysfunction (ED) after radical radiotherapy for clinically localized prostate carcinoma. A prospective multi-Institute study (DUE-01) was implemented with the aim to assess the predictive parameters of ED. Previously, an evaluation of inter-observer variations of PB contouring was mandatory in order to quantify its impact on PB dose-volume parameters by means of a dummy run exercise. Fifteen observers, from different Institutes, drew the PB on the planning CT images of ten patients; inter-observer variations were analysed in terms of PB volume variation and cranial/caudal limits. 3DCRT treatment plans were simulated to evaluate the impact of PB contouring inter-variability on dose-volume statistics parameters. For DVH analysis the values of PB mean dose and the volume of PB receiving more than 50 Gy and 70 Gy (V50 and V70, respectively) were considered. Systematic differences from the average values were assessed by the Wilcoxon test. Seven observers systematically overestimated or underestimated the PB volume with deviations from the average volumes ranging between -48% and +34% (p < 0.05). The analysis of the cranial and caudal borders showed a prevalence of random over systematic deviations. Inter-observer contouring variability strongly impacts on DVH parameters, although standard deviations of inter-patient differences were larger than inter-observer variations: 14.5 Gy versus 6.8 Gy for mean PB dose, 23.0% versus 11.0% and 16.8% versus 9.3% for V50 and V70 respectively. In conclusion, despite the large inter-observer variation in contouring PB, a large multi-centric study may have the possibility to detect a possible correlation between PB % dose-volume parameters and ED. The impact of contouring uncertainty could be reduced by 'a posteriori' contouring from a single observer or by introducing

  20. Control volume based hydrocephalus research; a phantom study

    Science.gov (United States)

    Cohen, Benjamin; Voorhees, Abram; Madsen, Joseph; Wei, Timothy

    2009-11-01

    Hydrocephalus is a complex spectrum of neurophysiological disorders involving perturbation of the intracranial contents; primarily increased intraventricular cerebrospinal fluid (CSF) volume and intracranial pressure are observed. CSF dynamics are highly coupled to the cerebral blood flows and pressures as well as the mechanical properties of the brain. Hydrocephalus, as such, is a very complex biological problem. We propose integral control volume analysis as a method of tracking these important interactions using mass and momentum conservation principles. As a first step in applying this methodology in humans, an in vitro phantom is used as a simplified model of the intracranial space. The phantom's design consists of a rigid container filled with a compressible gel. Within the gel a hollow spherical cavity represents the ventricular system and a cylindrical passage represents the spinal canal. A computer controlled piston pump supplies sinusoidal volume fluctuations into and out of the flow phantom. MRI is used to measure fluid velocity and volume change as functions of time. Independent pressure measurements and momentum flow rate measurements are used to calibrate the MRI data. These data are used as a framework for future work with live patients and normal individuals. Flow and pressure measurements on the flow phantom will be presented through the control volume framework.

  1. Applying ARIMA model for annual volume time series of the Magdalena River

    Directory of Open Access Journals (Sweden)

    Gloria Amaris

    2017-04-01

    Conclusions: The simulated results obtained with the ARIMA model compared to the observed data showed a fairly good adjustment of the minimum and maximum magnitudes. This allows concluding that it is a good tool for estimating minimum and maximum volumes, even though this model is not capable of simulating the exact behaviour of an annual volume time series.

  2. Estimation of lung volume and pulmonary blood volume from radioisotopic images

    International Nuclear Information System (INIS)

    Kanazawa, Minoru

    1989-01-01

    Lung volume and pulmonary blood volume in man were estimated from the radioisotopic image using single photon emission computed tomography (SPECT). Six healthy volunteers were studied in a supine position with normal and altered lung volumes by applying continuous negative body-surface pressure (CNP) and by positive end-expiratory pressure (PEEP). 99m Tc labeled human serum albumin was administered as an aerosol to image the lungs. The CNP caused the diaphragm to be lowered and it increased the mean lung tissue volume obtained by SPECT from 3.09±0.49 l for baseline to 3.67±0.62 l for 10 cmH 2 O (p 2 O (p 2 O), respectively. The PEEP also increased the lung tissue volume to 3.68±0.68 l for 10 cmH 2 O as compared with the baseline (p 2 O PEEP. The lung tissue volume obtained by SPECT showed a positive correlation with functional residual capacity measured by the He dilution method (r=0.91, p 99m Tc-labeled red blood cells. The L/H ratio decreased after either the CNP or PEEP, suggesting a decrease in the blood volume per unit lung volume. However, it was suggested that the total pulmonary blood volume increased slightly either on the CNP (+7.4% for 10 cmH 2 O, p 2 O,p<0.05) when we extrapolated the L/H ratio to the whole lungs by multiplying the lung tissue volume obtained by SPECT. We concluded that SPECT could offer access to the estimation of lung volume and pulmonary blood volume in vivo. (author)

  3. Three-dimensional segmentation of pulmonary artery volume from thoracic computed tomography imaging

    Science.gov (United States)

    Lindenmaier, Tamas J.; Sheikh, Khadija; Bluemke, Emma; Gyacskov, Igor; Mura, Marco; Licskai, Christopher; Mielniczuk, Lisa; Fenster, Aaron; Cunningham, Ian A.; Parraga, Grace

    2015-03-01

    Chronic obstructive pulmonary disease (COPD), is a major contributor to hospitalization and healthcare costs in North America. While the hallmark of COPD is airflow limitation, it is also associated with abnormalities of the cardiovascular system. Enlargement of the pulmonary artery (PA) is a morphological marker of pulmonary hypertension, and was previously shown to predict acute exacerbations using a one-dimensional diameter measurement of the main PA. We hypothesized that a three-dimensional (3D) quantification of PA size would be more sensitive than 1D methods and encompass morphological changes along the entire central pulmonary artery. Hence, we developed a 3D measurement of the main (MPA), left (LPA) and right (RPA) pulmonary arteries as well as total PA volume (TPAV) from thoracic CT images. This approach incorporates segmentation of pulmonary vessels in cross-section for the MPA, LPA and RPA to provide an estimate of their volumes. Three observers performed five repeated measurements for 15 ex-smokers with ≥10 pack-years, and randomly identified from a larger dataset of 199 patients. There was a strong agreement (r2=0.76) for PA volume and PA diameter measurements, which was used as a gold standard. Observer measurements were strongly correlated and coefficients of variation for observer 1 (MPA:2%, LPA:3%, RPA:2%, TPA:2%) were not significantly different from observer 2 and 3 results. In conclusion, we generated manual 3D pulmonary artery volume measurements from thoracic CT images that can be performed with high reproducibility. Future work will involve automation for implementation in clinical workflows.

  4. Brain-derived Neurotrophic Factor (BDNF) and gray matter volume in bipolar disorder.

    Science.gov (United States)

    Poletti, S; Aggio, V; Hoogenboezem, T A; Ambrée, O; de Wit, H; Wijkhuijs, A J M; Locatelli, C; Colombo, C; Arolt, V; Drexhage, H A; Benedetti, F

    2017-02-01

    Bipolar Disorder (BD) is a severe psychiatric condition characterized by grey matter (GM) volumes reduction. Neurotrophic factors have been suggested to play a role in the neuroprogressive changes during the illness course. In particular peripheral brain-derived neurotrophic factor (BDNF) has been proposed as a potential biomarker related to disease activity and neuroprogression in BD. The aim of our study was to investigate if serum levels of BDNF are associated with GM volumes in BD patients and healthy controls (HC). We studied 36 inpatients affected by a major depressive episode in course of BD type I and 17 HC. Analysis of variance was performed to investigate the effect of diagnosis on GM volumes in the whole brain. Threshold for significance was PBDNF levels compared with HC. Reduced GM volumes in BD patients compared to HC were observed in several brain areas, encompassing the caudate head, superior temporal gyrus, insula, fusiform gyrus, parahippocampal gyrus, and anterior cingulate cortex. The interaction analysis between BDNF levels and diagnosis showed a significant effect in the middle frontal gyrus. HC reported higher BDNF levels associated with higher GM volumes, whereas no association between BDNF and GM volumes was observed in BD. Our study seems to suggest that although the production of BDNF is increased in BD possibly to prevent and repair neural damage, its effects could be hampered by underlying neuroinflammatory processes interfering with the neurodevelopmental role of BDNF. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  5. Graphical User Interfaces for Volume Rendering Applications in Medical Imaging

    OpenAIRE

    Lindfors, Lisa; Lindmark, Hanna

    2002-01-01

    Volume rendering applications are used in medical imaging in order to facilitate the analysis of three-dimensional image data. This study focuses on how to improve the usability of graphical user interfaces of these systems, by gathering user requirements. This is achieved by evaluations of existing systems, together with interviews and observations at clinics in Sweden that use volume rendering to some extent. The usability of the applications of today is not sufficient, according to the use...

  6. That's Not Montessori

    Science.gov (United States)

    Peters, Dane L.

    2009-01-01

    The author could not contain herself one day at school recently when a parent of three children shared something she had heard from her eldest daughter. That morning, the eldest daughter was grumbling about the fact that she and her Lower Elementary brother had to go to school while her Preschool brother did not, and she announced to her mother,…

  7. Estimation of lung volumes from chest radiographs using shape information

    International Nuclear Information System (INIS)

    Pierce, R.J.; Brown, D.J.; Holmes, M.; Cumming, G.; Denison, D.M.

    1979-01-01

    The cross-sectional shapes of the chest and its contained structures were assessed in post-mortem anatomical sections and from computerised tomographic scans in living subjects. These shapes are described by simple equations that can be used to increase the accuracy of measuring lung volumes from chest radiographs. Radiographic estimates of total lung capacity, using the equations, were compared with plethysmographic and single-breath helium dilution measurements in 35 normal subjects. After correction for posture effects the radiographic estimates of TLC, which measure the displacement volume of the lung, exceeded the plethysmographic estimates of contained gas volume by a mean of 720 ml, which was taken as the volume of tissue, blood, and water in the lungs. The single-breath dilution estimates of TLC fell short of the plethysmographic values by a mean of 480 ml, taken as the volume of contained gas that was inaccessible to helium in 10 seconds. The tomographic studies suggested that the radiographic technique of measuring lung displacement volumes has an accuracy of +- 210 ml. The method is rapid and simple to use and the intra- and inter-observer variabilities of <1% and <5% respectively. (author)

  8. Volume of sealer in the apical region of teeth filled by different techniques: a micro-CT analysis

    Directory of Open Access Journals (Sweden)

    Vanessa Lessa ARAÚJO

    2016-01-01

    Full Text Available Abstract The volume of sealer in the apical 1 mm of teeth filled using different techniques was evaluated by micro-commuted tomography (micro-CT. Sixty-four maxillary central incisors were prepared using NiTi rotary instruments. Teeth were randomly distributed into four groups according to root canal sealers (AH Plus, Endofill, Sealapex, and Sealer 26 and subdivided into two subgroups according to the filling techniques (active and passive lateral condensation; n = 8 each. Subsequently, teeth were examined using the 1174 SkyScan micro-CT device. Images were reconstructed using the NRecon software, and the sealer volume (mm3 in the apical region was analyzed using the two-way ANOVA and post-hoc Student–Newman–Keuls test (α = ٠.٠٥. The lowest volume of sealer was observed in teeth filled with Sealapex (0.100 ± 0.009 and Endofill (0.103 ± 0.010. The highest volume was observed in teeth filled with AH Plus (0.112 ± 0.008 and Sealer 26 (0.109 ± 0.018 (p > 0.05. Regarding the filling technique, a lower sealer volume was observed using the active lateral condensation technique compared with that using the passive lateral condensation technique (0.100 ± 0.010 vs. 0.111 ± 0.012 (p < 0.05. Therefore, the lowest volume of sealer was observed in teeth filled with Sealapex and Endofill using the active lateral condensation technique.

  9. Assessment of in vivo MR imaging compared to physical sections in vitro-A quantitative study of brain volumes using stereology

    DEFF Research Database (Denmark)

    Jelsing, Jacob; Rostrup, Egill; Markenroth, Karin

    2005-01-01

    The object of the present study was to compare stereological estimates of brain volumes obtained in vivo by magnetic resonance imaging (MRI) to corresponding volumes from physical sections in vitro. Brains of ten domestic pigs were imaged using a 3-T scanner. The volumes of different brain....... However, although intraobserver difference of MRI estimates was acceptable, the interobserver difference was not. A statistical highly significant difference of 11-41% was observed between observers for volume estimates of all compartments considered. The study demonstrates that quantitative MRI...

  10. Blood volume studies

    International Nuclear Information System (INIS)

    Lewis, S.M.; Yin, J.A.L.

    1986-01-01

    The use of dilution analysis with such radioisotopes as 51 Cr, 32 P, sup(99m)Tc and sup(113m)In for measuring red cell volume is reviewed briefly. The use of 125 I and 131 I for plasma volume studies is also considered and the subsequent determination of total blood volume discussed, together with the role of the splenic red cell volume. Substantial bibliography. (UK)

  11. Calcul statistique du volume des blocs matriciels d'un gisement fissuré The Statistical Computing of Matrix Block Volume in a Fissured Reservoir

    Directory of Open Access Journals (Sweden)

    Guez F.

    2006-11-01

    Full Text Available La recherche des conditions optimales d'exploitation d'un gisement fissuré repose sur une bonne description de la fissuration. En conséquence il est nécessaire de définir les dimensions et volumes des blocs matriciels en chaque point d'une structure. Or la géométrie du milieu (juxtaposition et formes des blocs est généralement trop complexe pour se prêter au calcul. Aussi, dans une précédente communication, avons-nous dû tourner cette difficulté par un raisonnement sur des moyennes (pendages, azimuts, espacement des fissures qui nous a conduits à un ordre de grandeur des volumes. Cependant un volume moyen ne peut pas rendre compte d'une loi de répartition des volumes des blocs. Or c'est cette répartition qui conditionne le choix d'une ou plusieurs méthodes successives de récupération. Aussi présentons-nous ici une méthode originale de calcul statistique de la loi de distribution des volumes des blocs matriciels, applicable en tout point d'un gisement. La part de gisement concernée par les blocs de volume donné en est déduite. La connaissance générale du phénomène de la fracturation sert de base au modèle. Les observations de subsurface sur la fracturation du gisement en fournissent les données (histogramme d'orientation et d'espacement des fissures.Une application au gisement d'Eschau (Alsace, France est rapportée ici pour illustrer la méthode. The search for optimum production conditions for a fissured reservoir depends on having a good description of the fissure pattern. Hence the sizes and volumes of the matrix blocks must be defined at all points in a structure. However, the geometry of the medium (juxtaposition and shapes of blocks in usually too complex for such computation. This is why, in a previous paper, we got around this problem by reasoning on the bases of averages (clips, azimuths, fissure spacing, and thot led us to an order of magnitude of the volumes. Yet a mean volume cannot be used to explain

  12. Is orbital volume associated with eyeball and visual cortex volume in humans?

    Science.gov (United States)

    Pearce, Eiluned; Bridge, Holly

    2013-01-01

    In humans orbital volume increases linearly with absolute latitude. Scaling across mammals between visual system components suggests that these larger orbits should translate into larger eyes and visual cortices in high latitude humans. Larger eyes at high latitudes may be required to maintain adequate visual acuity and enhance visual sensitivity under lower light levels. To test the assumption that orbital volume can accurately index eyeball and visual cortex volumes specifically in humans. Structural Magnetic Resonance Imaging (MRI) techniques are employed to measure eye and orbit (n = 88) and brain and visual cortex (n = 99) volumes in living humans. Facial dimensions and foramen magnum area (a proxy for body mass) were also measured. A significant positive linear relationship was found between (i) orbital and eyeball volumes, (ii) eyeball and visual cortex grey matter volumes and (iii) different visual cortical areas, independently of overall brain volume. In humans the components of the visual system scale from orbit to eye to visual cortex volume independently of overall brain size. These findings indicate that orbit volume can index eye and visual cortex volume in humans, suggesting that larger high latitude orbits do translate into larger visual cortices.

  13. Ovarian volume and antral follicle count assessed by MRI and transvaginal ultrasonography: a methodological study.

    Science.gov (United States)

    Leonhardt, Henrik; Gull, Berit; Stener-Victorin, Elisabet; Hellström, Mikael

    2014-03-01

    Ultrasonographic measurements of ovarian volume and antral follicle count are of clinical importance as diagnostic features of polycystic ovarian syndrome (PCOS), and as a parameter in estimation of ovarian follicular reserve in infertility care. To compare two-dimensional (2D)/three-dimensional (3D) transvaginal ultrasonography (TVUS) and magnetic resonance imaging (MRI) for estimation of ovarian volume and antral follicle count, and to assess reproducibility and inter-observer agreement of MRI measurements. Volumes of 172 ovaries in 99 women aged 21-37 years were calculated (length x width x height x 0.523) with conventional 2D TVUS and 2D MRI. Semi-automatic estimates of ovarian volumes were obtained by 3D MRI. Antral follicles were counted manually on 2D MRI and automatically by 3D TVUS (SonoAVC), and stratified according to follicle size. Mean ovarian volume assessed by 2D TVUS (13.1 ± 6.4 mL) was larger than assessed by 2D MRI (9.6 ± 4.1) and 3D MRI (11.4 ± 4.5) (P 0.77. 2D MRI reveals more antral follicles, especially of small size, than 3D TVUS. Ovarian volume estimation by MRI provides smaller volumes than by the reference standard 2D TVUS. Ovarian volume estimation by 3D MRI, allowing independence of non-ellipsoid ovarian shape measurement errors, provides volumes closer to 2D TVUS values than does 2D MRI. Reproducibility and inter-observer agreement of 2D MRI measurements of ovarian volume and total follicle count are good.

  14. Inter- and intra-observer variability in prostate definition with tissue harmonic and brightness mode imaging.

    Science.gov (United States)

    Sandhu, Gurpreet Kaur; Dunscombe, Peter; Meyer, Tyler; Pavamani, Simon; Khan, Rao

    2012-01-01

    The objective of this study was to compare the relative utility of tissue harmonic (H) and brightness (B) transrectal ultrasound (TRUS) images of the prostate by studying interobserver and intraobserver variation in prostate delineation. Ten patients with early-stage disease were randomly selected. TRUS images of prostates were acquired using B and H modes. The prostates on all images were contoured by an experienced radiation oncologist (RO) and five equally trained observers. The observers were blinded to information regarding patient and imaging mode. The volumes of prostate glands and areas of midgland slices were calculated. Volumes contoured were compared among the observers and between observer group and RO. Contours on one patient were repeated five times by four observers to evaluate the intraobserver variability. A one-sample Student t-test showed the volumes outlined by five observers are in agreement (p > 0.05) with the RO. Paired Student t-test showed prostate volumes (p = 0.008) and midgland areas (p = 0.006) with H mode were significantly smaller than that with B mode. Two-factor analysis of variances showed significant interobserver variability (p standard deviation of mean volumes and areas, and concordance indices. It was found that for small glands (≤35 cc) H mode provided greater interobserver consistency; however, for large glands (≥35 cc), B mode provided more consistent estimates. H mode provided superior inter- and intraobserver agreement in prostate volume definition for small to medium prostates. In large glands, H mode does not exhibit any additional advantage. Although harmonic imaging has not proven advantageous for all cases, its utilization seems to be judicious for small prostates. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  15. Childhood trauma and hippocampal and amygdalar volumes in first-episode psychosis.

    Science.gov (United States)

    Hoy, Katrina; Barrett, Suzanne; Shannon, Ciaran; Campbell, Clodagh; Watson, David; Rushe, Teresa; Shevlin, Mark; Bai, Feng; Cooper, Stephen; Mulholland, Ciaran

    2012-11-01

    A history of childhood trauma is common in individuals who later develop psychosis. Similar neuroanatomical abnormalities are observed in people who have been exposed to childhood trauma and people with psychosis. However, the relationship between childhood trauma and such abnormalities in psychosis has not been investigated. This study aimed to explore the association between the experience of childhood trauma and hippocampal and amygdalar volumes in a first-episode psychosis (FEP) population. The study employed an observational retrospective design. Twenty-one individuals, who had previously undergone magnetic resonance imaging procedures as part of the longitudinal Northern Ireland First-Episode Psychosis Study, completed measures assessing traumatic experiences and were included in the analysis. Data were subject to correlation analyses (r and r (pb)). Potential confounding variables (age at FEP and delay to scan from recruitment) were selected a priori for inclusion in multiple regression analyses. There was a high prevalence of lifetime (95%) and childhood (76%) trauma in the sample. The experience of childhood trauma was a significant predictor of left hippocampal volume, although age at FEP also significantly contributed to this model. There was no significant association between predictor variables and right hippocampal volume. The experience of childhood trauma was a significant predictor of right and total amygdalar volumes and the hippocampal/amygdalar complex volume as a whole. The findings indicate that childhood trauma is associated with neuroanatomical measures in FEP. Future research controlling for childhood traumatic experiences may contribute to explaining brain morphology in people with psychosis.

  16. Gray matter volume and rapid decision-making in major depressive disorder.

    Science.gov (United States)

    Nakano, Masayuki; Matsuo, Koji; Nakashima, Mami; Matsubara, Toshio; Harada, Kenichiro; Egashira, Kazuteru; Masaki, Hiroaki; Takahashi, Kanji; Watanabe, Yoshifumi

    2014-01-03

    Reduced motivation and blunted decision-making are key features of major depressive disorder (MDD). Patients with MDD show abnormal decision-making when given negative feedback regarding a reward. The brain mechanisms underpinning this behavior remain unclear. In the present study, we examined the association between rapid decision-making with negative feedback and brain volume in MDD. Thirty-six patients with MDD and 54 age-, sex- and IQ-matched healthy subjects were studied. Subjects performed a rapid decision-making monetary task in which participants could make high- or low-risk choices. We compared between the 2 groups the probability that a high-risk choice followed negative feedback. In addition, we used voxel-based morphometry (VBM) to compare between group differences in gray matter volume, and the correlation between the probability for high-risk choices and brain volume. Compared to the healthy group, the MDD group showed significantly lower probabilities for high-risk choices following negative feedback. VBM analysis revealed that the MDD group had less gray matter volume in the right medial prefrontal cortex and orbitofrontal cortex (OFC) compared to the healthy group. The right OFC volume was negatively correlated with the probability that a high-risk choice followed negative feedback in patients with MDD. We did not observe these trends in healthy subjects. Patients with MDD show reduced motivation for monetary incentives when they were required to make rapid decisions following negative feedback. We observed a correlation between this reduced motivation and gray matter volume in the medial and ventral prefrontal cortex, which suggests that these brain regions are likely involved in the pathophysiology of aberrant decision-making in MDD. © 2013.

  17. Sliding mode control and observation

    CERN Document Server

    Shtessel, Yuri; Fridman, Leonid; Levant, Arie

    2014-01-01

    The sliding mode control methodology has proven effective in dealing with complex dynamical systems affected by disturbances, uncertainties and unmodeled dynamics. Robust control technology based on this methodology has been applied to many real-world problems, especially in the areas of aerospace control, electric power systems, electromechanical systems, and robotics. Sliding Mode Control and Observation represents the first textbook that starts with classical sliding mode control techniques and progresses toward newly developed higher-order sliding mode control and observation algorithms and their applications. The present volume addresses a range of sliding mode control issues, including: *Conventional sliding mode controller and observer design *Second-order sliding mode controllers and differentiators *Frequency domain analysis of conventional and second-order sliding mode controllers *Higher-order sliding mode controllers and differentiators *Higher-order sliding mode observers *Sliding mode disturbanc...

  18. A Volume-Limited Sample of L and T Dwarfs Defined by Parallaxes

    Science.gov (United States)

    Best, William M. J.; Liu, Michael C.; Magnier, Eugene; Dupuy, Trent

    2018-01-01

    Volume-limited samples are the gold standard for stellar population studies, as they enable unbiased measurements of space densities and luminosity functions. Parallaxes are the most direct measures of distance and are therefore essential for defining high-confidence volume limited samples. Previous efforts to model the local brown dwarf population were hampered by samples based on a small number of parallaxes. We are using UKIRT/WFCAM to conduct the largest near-infrared program to date to measure parallaxes and proper motions of L and T dwarfs. For the past 3+ years we have monitored over 350 targets, ≈90% of which are too faint to be observed by Gaia. We present preliminary results from our observations. Our program more than doubles the number of known L and T dwarf parallaxes, defining a volume-limited sample of ≈400 L0-T6 dwarfs out to 25 parsecs, the first L and T dwarf sample of this size and depth based entirely on parallaxes. Our sample will combine with the upcoming stellar census from Gaia DR2 parallaxes to form a complete volume-limited sample of nearby stars and brown dwarfs.

  19. Estimation of the volume and percent uptake of the liver and spleen by SPECT

    International Nuclear Information System (INIS)

    Yamagata, Atushi

    1988-01-01

    The volume and percent uptake of the liver and spleen were estimated with single photon emission computed tomography (SPECT) using 99m Tc-phytate. Clinical usefulness of these parameters was evaluated by comparison with other liver function tests in 87 patients including 25 normal controls, 24 liver cirrhosis and 16 other chronic liver diseases. SPECT images were obtained by Maxi Camera 400T. Cut-off level for reconstruction of images and relationship between counts and activity (mCi) were obtained from phantom studies. Volumes estimated using SPECT and computed tomography were compared in 16 patients. Results obtained were as follows. 1) Optimal cut-off level for measurement of volumes for the liver was 37 % and for the spleen was 42 %. 2) Correlation between organ volumes estimated with CT and SPECT was good (r = 0.92 for the liver and r = 0.96 for the spleen), although volumes measured with SPECT were larger than those with CT. 3) Significant differences of percent uptake were observed between normal controls and liver cirrhosis. 4) Better correlation between spleen volumes and uptake was recognized in cases without liver cirrhosis than in cases with liver cirrhosis. The spleen uptake in liver cirrhosis was higher than those in others in comparison with the volume. 5) The liver/spleen ratio of 99m Tc-phytae uptake could most clearly differentiate liver cirrhosis from others. 6) Negative correlation was observed between liver volume or uptake and ICG (R 15 ). Estimation of volume and uptake of the liver and spleen could be a useful procedure to assess liver function, probably related with effective hepatic blood flow in liver cirrhosis. (author)

  20. Reduction of heart volume during neoadjuvant chemoradiation in patients with resectable esophageal cancer

    International Nuclear Information System (INIS)

    Haj Mohammad, Nadia; Kamphuis, Martijn; Hulshof, Maarten C.C.M.; Lutkenhaus, Lotte J.; Gisbertz, Suzanne S.; Bergman, Jacques J.G.H.M.; Bruin-Bon, H.A.C.M. Rianne de; Geijsen, Elisabeth D.; Bel, Arjan; Boekholdt, S. Mathijs; Laarhoven, Hanneke W.M. van

    2015-01-01

    Background and purpose: Neoadjuvant chemoradiation (nCRT) followed by surgery is considered curative intent treatment for patients with resectable esophageal cancer. The aim was to establish hemodynamic aspects of changes in heart volume and to explore whether changes in heart volume resulted in clinically relevant changes in the dose distribution of radiotherapy. Methods: A prospective study was conducted in patients who were treated with nCRT consisting of carboplatin and paclitaxel concomitant with radiotherapy (41.4 Gy/1.8 Gy per fraction). Physical parameters, cardiac volume on CT and Cone beam CT, cardiac blood markers and cardiac ultrasound were obtained. Results: In 23 patients a significant decrease of 55.3 ml in heart volume was detected (95% CI 36.7–73.8 ml, p < 0.001). There was a decrease in both systolic (mean decrease 18 mmHg, 95% CI 11–26 mmHg, p < 0.001) and diastolic blood pressure (mean decrease 8 mmHg, 95% CI 2–14 mmHg, p = 0.008) and an increase in heart rate with 6 beats/min (95% CI 1–11 beats/min, p = 0.021). Except for Troponin T, no change in other cardiac markers and echocardiography parameters were observed. The change in heart volume did not result in a clinically relevant change in radiation dose distribution. Conclusion: Heart volume was significantly reduced, but was not accompanied by overt cardiac dysfunction. All observed changes in hemodynamic parameters are consistent with volume depletion. Adaptation of the treatment plan during the course of radiotherapy is not advocated

  1. Predicting uncertainty in future marine ice sheet volume using Bayesian statistical methods

    Science.gov (United States)

    Davis, A. D.

    2015-12-01

    The marine ice instability can trigger rapid retreat of marine ice streams. Recent observations suggest that marine ice systems in West Antarctica have begun retreating. However, unknown ice dynamics, computationally intensive mathematical models, and uncertain parameters in these models make predicting retreat rate and ice volume difficult. In this work, we fuse current observational data with ice stream/shelf models to develop probabilistic predictions of future grounded ice sheet volume. Given observational data (e.g., thickness, surface elevation, and velocity) and a forward model that relates uncertain parameters (e.g., basal friction and basal topography) to these observations, we use a Bayesian framework to define a posterior distribution over the parameters. A stochastic predictive model then propagates uncertainties in these parameters to uncertainty in a particular quantity of interest (QoI)---here, the volume of grounded ice at a specified future time. While the Bayesian approach can in principle characterize the posterior predictive distribution of the QoI, the computational cost of both the forward and predictive models makes this effort prohibitively expensive. To tackle this challenge, we introduce a new Markov chain Monte Carlo method that constructs convergent approximations of the QoI target density in an online fashion, yielding accurate characterizations of future ice sheet volume at significantly reduced computational cost.Our second goal is to attribute uncertainty in these Bayesian predictions to uncertainties in particular parameters. Doing so can help target data collection, for the purpose of constraining the parameters that contribute most strongly to uncertainty in the future volume of grounded ice. For instance, smaller uncertainties in parameters to which the QoI is highly sensitive may account for more variability in the prediction than larger uncertainties in parameters to which the QoI is less sensitive. We use global sensitivity

  2. The complex relationship between lung tumor volume and survival in patients with non-small cell lung cancer treated by definitive radiotherapy: A prospective, observational prognostic factor study of the Trans-Tasman Radiation Oncology Group (TROG 99.05)

    International Nuclear Information System (INIS)

    Ball, David L.; Fisher, Richard J.; Burmeister, Bryan H.; Poulsen, Michael G.; Graham, Peter H.; Penniment, Michael G.; Vinod, Shalini K.; Krawitz, Hedley E.; Joseph, David J.; Wheeler, Greg C.; McClure, Bev E.

    2013-01-01

    Background and purpose: To investigate the hypothesis that primary tumor volume is prognostic independent of T and N stages in patients with non-small cell lung cancer (NSCLC) treated by definitive radiotherapy. Materials and methods: Multicenter prospective observational study. Patient eligibility: pathologically proven stage I–III non-small cell lung cancer planned for definitive radiotherapy (minimum 50 Gy in 20 fractions) using CT-based contouring. Volumes of the primary tumor and enlarged nodes were measured according to a standardized protocol. Survival was adjusted for the effect of T and N stage. Results: There were 509 eligible patients. Five-year survival rates for tumor volume grouped by quartiles were, for increasing tumor volume, 22%, 14%, 15% and 21%. Larger primary tumor volume was associated with shorter survival (HR = 1.060 (per doubling); 95% CI 1.01–1.12; P = 0.029). However, after adjusting for the effects of T and N stage, there was no evidence for an association (HR = 1.029, 95% CI, 0.96–1.10, P = 0.39). There was evidence, however, that larger primary tumor volume was associated with an increased risk of dying, independently of T and N stage, in the first 18 months but not beyond. Conclusions: In patients treated by non-surgical means we were unable to show that lung tumor volume, overall, provides additional prognostic information beyond the T and N stage (TNM, 6th edition). There is evidence, however, that larger primary tumor volume adversely affects outcome only within the first 18 months. Larger tumor size alone should not by itself exclude patients from curative (chemo)radiotherapy

  3. Sea-ice monitoring by ship-based visual observation during JARE ―Simplification of observation method based on the ASPeCt protocol―

    OpenAIRE

    Kay I. Ohshima; Shuki Ushio; Akihisa S. Otsuki

    2006-01-01

    A protocol for ship-based visual observation of sea ice is proposed for the Japanese Antarctic Research Expedition (JARE). The protocol is a simplified version of the ASPeCt protocol, used for extracting quantitative information on sea ice. The ship-based visual observations started from JARE-46. In the pack ice region, ice thickness, ratio of deformed ice, and total ice volume increased toward the coast. Continuous monitoring of sea ice, particularly its thickness, by ship-based observation ...

  4. Hospital volume and the risk of revision in Oxford unicompartmental knee arthroplasty in the Nordic countries -an observational study of 14,496 cases

    DEFF Research Database (Denmark)

    Badawy, Mona; Fenstad, Anne M.; Bartz-Johannessen, Christoffer A.

    2017-01-01

    Background: High procedure volume and dedication to unicompartmental knee arthroplasty (UKA) has been suggested to improve revision rates. This study aimed to quantify the annual hospital volume effect on revision risk in Oxfordu? nicompartmental knee arthroplasty in the Nordic countries. Methods......). The outcome was revision risk after 2 and 10 years calculated using Kaplan Meier method. Multivariate Cox regression analysis was used to assess the Hazard Ratio (HR) of any revision due to specific reasons with 95% confidence intervals (CI). Results: The implant survival was 80% at 10 years in the volume...

  5. Depth of Field Effects for Interactive Direct Volume Rendering

    KAUST Repository

    Schott, Mathias; Pascal Grosset, A.V.; Martin, Tobias; Pegoraro, Vincent; Smith, Sean T.; Hansen, Charles D.

    2011-01-01

    In this paper, a method for interactive direct volume rendering is proposed for computing depth of field effects, which previously were shown to aid observers in depth and size perception of synthetically generated images. The presented technique extends those benefits to volume rendering visualizations of 3D scalar fields from CT/MRI scanners or numerical simulations. It is based on incremental filtering and as such does not depend on any precomputation, thus allowing interactive explorations of volumetric data sets via on-the-fly editing of the shading model parameters or (multi-dimensional) transfer functions. © 2011 The Author(s).

  6. Depth of Field Effects for Interactive Direct Volume Rendering

    KAUST Repository

    Schott, Mathias

    2011-06-01

    In this paper, a method for interactive direct volume rendering is proposed for computing depth of field effects, which previously were shown to aid observers in depth and size perception of synthetically generated images. The presented technique extends those benefits to volume rendering visualizations of 3D scalar fields from CT/MRI scanners or numerical simulations. It is based on incremental filtering and as such does not depend on any precomputation, thus allowing interactive explorations of volumetric data sets via on-the-fly editing of the shading model parameters or (multi-dimensional) transfer functions. © 2011 The Author(s).

  7. Forced volume magnetostriction in Mn3.3Sn0.7C compound at room temperature

    International Nuclear Information System (INIS)

    Wen Yongchun; Wang Cong; Sun Ying; Nie Man; Chu Lihua

    2010-01-01

    The negative volume magnetostriction in the external magnetic field for antiperovskite Mn 3.3 Sn 0.7 C compound is discovered. Its magnetic transition temperature from paramagnetism to ferrimagnetism is 348 K. The linear and volume magnetostrictions were investigated by measuring the change in length along the three-dimensional directions of the square samples at room temperature. Volume contraction was observed along all of the three directions throughout the whole magnetization. The value of volume magnetostriction is -44x10 -6 at 1.5 T. The magnetization saturates basically at 1.5 T, however the volume magnetostriction should be higher with further increase in magnetic field.

  8. Introduction to "Global Tsunami Science: Past and Future, Volume II"

    Science.gov (United States)

    Rabinovich, Alexander B.; Fritz, Hermann M.; Tanioka, Yuichiro; Geist, Eric L.

    2017-08-01

    Twenty-two papers on the study of tsunamis are included in Volume II of the PAGEOPH topical issue "Global Tsunami Science: Past and Future". Volume I of this topical issue was published as PAGEOPH, vol. 173, No. 12, 2016 (Eds., E. L. Geist, H. M. Fritz, A. B. Rabinovich, and Y. Tanioka). Three papers in Volume II focus on details of the 2011 and 2016 tsunami-generating earthquakes offshore of Tohoku, Japan. The next six papers describe important case studies and observations of recent and historical events. Four papers related to tsunami hazard assessment are followed by three papers on tsunami hydrodynamics and numerical modelling. Three papers discuss problems of tsunami warning and real-time forecasting. The final set of three papers importantly investigates tsunamis generated by non-seismic sources: volcanic explosions, landslides, and meteorological disturbances. Collectively, this volume highlights contemporary trends in global tsunami research, both fundamental and applied toward hazard assessment and mitigation.

  9. 11C-methionine PET improves the target volume delineation of meningiomas treated with stereotactic fractionated radiotherapy

    International Nuclear Information System (INIS)

    Grosu, Anca-Ligia; Weber, Wolfgang A.; Astner, Sabrina T.; Adam, Markus; Krause, Bernd J.; Schwaiger, Markus; Molls, Michael; Nieder, Carsten

    2006-01-01

    Purpose: To evaluate the role of 11 C-methionine positron emission tomography (MET-PET) in target volume delineation for meningiomas and to determine the interobserver variability. Methods and Materials: Two independent observers performed treatment planning in 10 patients according to a prospective written protocol. In the first step, they used coregistered computed tomography (CT) and magnetic resonance imaging (MRI). In the second step, MET-PET was added to CT/MRI (image fusion based on mutual information). Results: The correlation between gross tumor volume (GTVs) delineated by the two observers based on CT/MRI was r = 0.855 (Spearman's correlation coefficient, p = 0.002) and r = 0.988 (p = 0.000) when MET-PET/CT/MRI were used. The number of patients with agreement in more then 80% of the outlined volume increased with the availability of MET-PET from 1 in 10 to 5 in 10. The median volume of intersection between the regions delineated by two observers increased significantly from 69% (from the composite volume) to 79%, by the addition of MET-PET (p = 0.005). The information of MET-PET was useful to delineate GTV in the area of cavernous sinus, orbit, and base of the skull. Conclusions: The hypothesis-generating findings of potential normal tissue sparing and reduced interobserver variability provide arguments for invasive studies of the correlation between MET-PET images and histologic tumor extension and for prospective trials of target volume delineation with CT/MRI/MET-PET image fusion

  10. Magmatic densities control erupted volumes in Icelandic volcanic systems

    Science.gov (United States)

    Hartley, Margaret; Maclennan, John

    2018-04-01

    Magmatic density and viscosity exert fundamental controls on the eruptibility of magmas. In this study, we investigate the extent to which magmatic physical properties control the eruptibility of magmas from Iceland's Northern Volcanic Zone (NVZ). By studying subaerial flows of known age and volume, we are able to directly relate erupted volumes to magmatic physical properties, a task that has been near-impossible when dealing with submarine samples dredged from mid-ocean ridges. We find a strong correlation between magmatic density and observed erupted volumes on the NVZ. Over 85% of the total volume of erupted material lies close to a density and viscosity minimum that corresponds to the composition of basalts at the arrival of plagioclase on the liquidus. These magmas are buoyant with respect to the Icelandic upper crust. However, a number of small-volume eruptions with densities greater than typical Icelandic upper crust are also found in Iceland's neovolcanic zones. We use a simple numerical model to demonstrate that the eruption of magmas with higher densities and viscosities is facilitated by the generation of overpressure in magma chambers in the lower crust and uppermost mantle. This conclusion is in agreement with petrological constraints on the depths of crystallisation under Iceland.

  11. Magmatic Densities Control Erupted Volumes in Icelandic Volcanic Systems

    Directory of Open Access Journals (Sweden)

    Margaret Hartley

    2018-04-01

    Full Text Available Magmatic density and viscosity exert fundamental controls on the eruptibility of magmas. In this study, we investigate the extent to which magmatic physical properties control the eruptibility of magmas from Iceland's Northern Volcanic Zone (NVZ. By studying subaerial flows of known age and volume, we are able to directly relate erupted volumes to magmatic physical properties, a task that has been near-impossible when dealing with submarine samples dredged from mid-ocean ridges. We find a strong correlation between magmatic density and observed erupted volumes on the NVZ. Over 85% of the total volume of erupted material lies close to a density and viscosity minimum that corresponds to the composition of basalts at the arrival of plagioclase on the liquidus. These magmas are buoyant with respect to the Icelandic upper crust. However, a number of small-volume eruptions with densities greater than typical Icelandic upper crust are also found in Iceland's neovolcanic zones. We use a simple numerical model to demonstrate that the eruption of magmas with higher densities and viscosities is facilitated by the generation of overpressure in magma chambers in the lower crust and uppermost mantle. This conclusion is in agreement with petrological constraints on the depths of crystallization under Iceland.

  12. Three-dimensional Mass Measurement of Subsolid Pulmonary Nodules on Chest CT: Intra and Inter-observer Variability

    Directory of Open Access Journals (Sweden)

    Huiting LIU

    2015-05-01

    Full Text Available Background and objective Subsolid pulmonary nodules tend to exhibit considerably slower growth rates than solid lesions, nevertheless, higher malignancy probability. The diagnosis of indeterminate nodules largely depends on the growth evaluation during follow-up. The growth can manifested as an increase in size or the appearance and/or subsequent increase of solid components. The mass reflect the product of volume and density and can be more sensitive in growth evaluation. However, the repeatability needs a further validation. The purpose of this study is to assess the intra and inter-observer variability of mass measurement for subsolid nodules. Methods 80 subsolid nodules in 44 patients were retrospectively enrolled. Both the volume and mass were measured by two radiologists using blind method independently. Intra-observer and inter-observer variability were analyzed and compared by Bland-Altman method intra-class correlation test and Wilcoxon test. Results Software achieved satisfied segmentation for 92.5% nodules. Of them, 35% underwent manual modification. The 95% limits of agreement for intra-observer variability were -11.5%-10.4% for mass and -8.4%-8.8% for volume. The 95% limits of agreement for inter-observer variability were -17.4%-19.3% for mass and -17.9%-19.4% for volume.The intra-class correlation foefficients between volume and mass measument was 0.95 and 0.93 (both P<0.001 and no significant differences (P=0.78, 0.09 was found for intra- and inter-observer variability. Manual modification of the segmentation caused the worse mass measurement repeatability in spite of the reader satisfaction. Conclusion The repeatability of mass measurement has no significant difference with that of volume measurement and may act as a reliable method in the follow-up of subsolid nodules.

  13. The plant cytoskeleton controls regulatory volume increase.

    Science.gov (United States)

    Liu, Qiong; Qiao, Fei; Ismail, Ahmed; Chang, Xiaoli; Nick, Peter

    2013-09-01

    The ability to adjust cell volume is required for the adaptation to osmotic stress. Plant protoplasts can swell within seconds in response to hypoosmotic shock suggesting that membrane material is released from internal stores. Since the stability of plant membranes depends on submembraneous actin, we asked, whether this regulatory volume control depends on the cytoskeleton. As system we used two cell lines from grapevine which differ in their osmotic tolerance and observed that the cytoskeleton responded differently in these two cell lines. To quantify the ability for regulatory volume control, we used hydraulic conductivity (Lp) as readout and demonstrated a role of the cytoskeleton in protoplast swelling. Chelation of calcium, inhibition of calcium channels, or manipulation of membrane fluidity, did not significantly alter Lp, whereas direct manipulation of the cytoskeleton via specific chemical reagents, or indirectly, through the bacterial elicitor Harpin or activation of phospholipase D, was effective. By optochemical engineering of actin using a caged form of the phytohormone auxin we can break the symmetry of actin organisation resulting in a localised deformation of cell shape indicative of a locally increased Lp. We interpret our findings in terms of a model, where the submembraneous cytoskeleton controls the release of intracellular membrane stores during regulatory volume change. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Adrenal gland volume measurement in septic shock and control patients: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Nougaret, Stephanie; Aufort, S.; Gallix, B. [Hopital Saint Eloi, Department of Abdominal Imaging, CHU Montpellier, Montpellier, Cedex 5 (France); Jung, B.; Chanques, G.; Jaber, S. [Hopital Saint Eloi, Intensive Care Unit, Department of Critical Care and Anesthesiology: DAR B, CHU Montpellier, Montpellier, Cedex 5 (France)

    2010-10-15

    To compare adrenal gland volume in septic shock patients and control patients by using semi-automated volumetry. Adrenal gland volume and its inter-observer variability were measured with tomodensitometry using semi-automated software in 104 septic shock patients and in 40 control patients. The volumes of control and septic shock patients were compared and the relationship between volume and outcome in intensive care was studied. The mean total volume of both adrenal glands was 7.2 {+-} 2.0 cm{sup 3} in control subjects and 13.3 {+-} 4.7 cm{sup 3} for total adrenal gland volume in septic shock patients (p < 0.0001). Measurement reproducibility was excellent with a concordance correlation coefficient value of 0.87. The increasing adrenal gland volume was associated with a higher rate of survival in intensive care. The present study reports that with semi-automated software, adrenal gland volume can be measured easily and reproducibly. Adrenal gland volume was found to be nearly double in sepsis compared with control patients. The absence of increased volume during sepsis would appear to be associated with a higher rate of mortality and may represent a prognosis factor which may help the clinician to guide their strategy. (orig.)

  15. Adrenal gland volume measurement in septic shock and control patients: a pilot study

    International Nuclear Information System (INIS)

    Nougaret, Stephanie; Aufort, S.; Gallix, B.; Jung, B.; Chanques, G.; Jaber, S.

    2010-01-01

    To compare adrenal gland volume in septic shock patients and control patients by using semi-automated volumetry. Adrenal gland volume and its inter-observer variability were measured with tomodensitometry using semi-automated software in 104 septic shock patients and in 40 control patients. The volumes of control and septic shock patients were compared and the relationship between volume and outcome in intensive care was studied. The mean total volume of both adrenal glands was 7.2 ± 2.0 cm 3 in control subjects and 13.3 ± 4.7 cm 3 for total adrenal gland volume in septic shock patients (p < 0.0001). Measurement reproducibility was excellent with a concordance correlation coefficient value of 0.87. The increasing adrenal gland volume was associated with a higher rate of survival in intensive care. The present study reports that with semi-automated software, adrenal gland volume can be measured easily and reproducibly. Adrenal gland volume was found to be nearly double in sepsis compared with control patients. The absence of increased volume during sepsis would appear to be associated with a higher rate of mortality and may represent a prognosis factor which may help the clinician to guide their strategy. (orig.)

  16. The effects of computed tomography with iterative reconstruction on solid pulmonary nodule volume quantification.

    Directory of Open Access Journals (Sweden)

    Martin J Willemink

    Full Text Available BACKGROUND: The objectives of this study were to evaluate the influence of iterative reconstruction (IR on pulmonary nodule volumetry with chest computed tomography (CT. METHODS: Twenty patients (12 women and 8 men, mean age 61.9, range 32-87 underwent evaluation of pulmonary nodules with a 64-slice CT-scanner. Data were reconstructed using filtered back projection (FBP and IR (Philips Healthcare, iDose(4-levels 2, 4 and 6 at similar radiation dose. Volumetric nodule measurements were performed with semi-automatic software on thin slice reconstructions. Only solid pulmonary nodules were measured, no additional selection criteria were used for the nature of nodules. For intra-observer and inter-observer variability, measurements were performed once by one observer and twice by another observer. Algorithms were compared using the concordance correlation-coefficient (pc and Friedman-test, and post-hoc analysis with the Wilcoxon-signed ranks-test with Bonferroni-correction (significance-level p<0.017. RESULTS: Seventy-eight nodules were present including 56 small nodules (volume<200 mm(3, diameter<8 mm and 22 large nodules (volume≥200 mm(3, diameter≥8 mm. No significant differences in measured pulmonary nodule volumes between FBP, iDose(4-levels 2, 4 and 6 were found in both small nodules and large nodules. FBP and iDose(4-levels 2, 4 and 6 were correlated with pc-values of 0.98 or higher for both small and large nodules. Pc-values of intra-observer and inter-observer variability were 0.98 or higher. CONCLUSIONS: Measurements of solid pulmonary nodule volume measured with standard-FBP were comparable with IR, regardless of the IR-level and no significant differences between measured volumes of both small and large solid nodules were found.

  17. Effect of varicocelectomy on testis volume and semen parameters in adolescents: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Tie Zhou

    2015-01-01

    Full Text Available Varicocele repair in adolescent remains controversial. Our aim is to identify and combine clinical trials results published thus far to ascertain the efficacy of varicocelectomy in improving testis volume and semen parameters compared with nontreatment control. A literature search was performed using Medline, Embase and Web of Science, which included results obtained from meta-analysis, randomized and nonrandomized controlled studies. The study population was adolescents with clinically palpable varicocele with or without the testicular asymmetry or abnormal semen parameters. Cases were allocated to treatment and observation groups, and testis volume or semen parameters were adopted as outcome measures. As a result, seven randomized controlled trials (RCTs and nonrandomized controlled trials studying bilateral testis volume or semen parameters in both treatment and observation groups were identified. Using a random effect model, mean difference of testis volume between the treatment group and the observation group was 2.9 ml (95% confidence interval [CI]: 0.6, 5.2; P< 0.05 for the varicocele side and 1.5 ml (95% CI: 0.3, 2.7; P< 0.05 for the healthy side. The random effect model analysis demonstrated that the mean difference of semen concentration, total semen motility, and normal morphology between the two groups was 13.7 × 10 6 ml−1 (95% CI: −1.4, 28.8; P = 0.075, 2.5% (95% CI: −3.6, 8.6; P= 0.424, and 2.9% (95% CI: −3.0, 8.7; P= 0.336 respectively. In conclusion, although varicocelectomy significantly improved bilateral testis volume in adolescents with varicocele compared with observation cases, semen parameters did not have any statistically significant difference between two groups. Well-planned, properly conducted RCTs are needed in order to confirm the above-mentioned conclusion further and to explore whether varicocele repair in adolescents could improve subsequently spontaneous pregnancy rates.

  18. Comparison of the outcomes for laparoscopic gastrectomy performed by the same surgeon between a low-volume hospital and a high-volume center.

    Science.gov (United States)

    Kim, Min Gyu; Kwon, Sung Joon

    2014-05-01

    The volume-outcome relationship in laparoscopic surgery is controversial. This study was designed to identify differences in laparoscopic gastrectomy outcomes between a low-volume hospital and a high-volume center and to provide guidelines for overcoming the problems associated with a low-volume hospital. From April 2009 to November 2012, one surgeon performed 134 totally laparoscopic distal gastrectomies (TLDGs) at a high-volume center (HVC; ASAN Medical Center) and at a low-volume hospital (LVH; Hanyang University Guri Hospital). All laparoscopically assisted gastrectomies were excluded from this study. During the early period of laparoscopic gastrectomy at the low-volume hospital, TLDG with Roux-en-Y gastrojejunostomy (RYGJ) was performed according to the surgeon's choice. The reconstruction method was classified as gastroduodenostomy (GD) or RYGJ. Early surgical outcomes achieved at the LVH were investigated and compared with those obtained at the HVC. The early surgical outcomes differed significantly between the two hospitals. In particular, the postoperative complication rate for the patients who underwent TLDG RYGJ at the LVH was higher than at the HVC (LVH 15.4 % vs. HVC 0 %; p = 0.037). Furthermore, significant differences were observed in the mean operation time (TLDG GD: LVH 141.0 min vs. HVC 117.4 min, p = 0.001; TLDG RYGJ: LVH 186.3 min vs. HVC 134.6 min, p = 0.009) and length of hospital stay (TLDG GD: LVH 8.1 days vs. HVC 7.2 days, p = 0.044; TLDG RYGJ: LVH 11.5 day vs. HVC 6.8 day, p = 0.009). Although all the operations were performed by one experienced surgeon, the early surgical outcomes differed significantly between the low- and high-volume hospitals. Low-volume hospitals often lack well-trained surgical professionals such as first assistants and scrub nurses. Therefore, the authors recommend that a surgeon who works at an LVH should assess potential personnel shortages and find a solution before operating.

  19. Quantification and variability in colonic volume with a novel magnetic resonance imaging method

    DEFF Research Database (Denmark)

    Nilsson, M; Sandberg, Thomas Holm; Poulsen, Jakob Lykke

    2015-01-01

    Background: Segmental distribution of colorectal volume is relevant in a number of diseases, but clinical and experimental use demands robust reliability and validity. Using a novel semi-automatic magnetic resonance imaging-based technique, the aims of this study were to describe: (i) inter......-individual and intra-individual variability of segmental colorectal volumes between two observations in healthy subjects and (ii) the change in segmental colorectal volume distribution before and after defecation. Methods: The inter-individual and intra-individual variability of four colorectal volumes (cecum...... (p = 0.02). Conclusions & Inferences: Imaging of segmental colorectal volume, morphology, and fecal accumulation is advantageous to conventional methods in its low variability, high spatial resolution, and its absence of contrast-enhancing agents and irradiation. Hence, the method is suitable...

  20. Gated CT imaging using a free-breathing respiration signal from flow-volume spirometry

    International Nuclear Information System (INIS)

    D'Souza, Warren D.; Kwok, Young; Deyoung, Chad; Zacharapoulos, Nicholas; Pepelea, Mark; Klahr, Paul; Yu, Cedric X.

    2005-01-01

    Respiration-induced tumor motion is known to cause artifacts on free-breathing spiral CT images used in treatment planning. This leads to inaccurate delineation of target volumes on planning CT images. Flow-volume spirometry has been used previously for breath-holds during CT scans and radiation treatments using the active breathing control (ABC) system. We have developed a prototype by extending the flow-volume spirometer device to obtain gated CT scans using a PQ 5000 single-slice CT scanner. To test our prototype, we designed motion phantoms to compare image quality obtained with and without gated CT scan acquisition. Spiral and axial (nongated and gated) CT scans were obtained of phantoms with motion periods of 3-5 s and amplitudes of 0.5-2 cm. Errors observed in the volume estimate of these structures were as much as 30% with moving phantoms during CT simulation. Application of motion-gated CT with active breathing control reduced these errors to within 5%. Motion-gated CT was then implemented in patients and the results are presented for two clinical cases: lung and abdomen. In each case, gated scans were acquired at end-inhalation, end-exhalation in addition to a conventional free-breathing (nongated) scan. The gated CT scans revealed reduced artifacts compared with the conventional free-breathing scan. Differences of up to 20% in the volume of the structures were observed between gated and free-breathing scans. A comparison of the overlap of structures between the gated and free-breathing scans revealed misalignment of the structures. These results demonstrate the ability of flow-volume spirometry to reduce errors in target volumes via gating during CT imaging

  1. Bare-Hand Volume Cracker for Raw Volume Data Analysis

    Directory of Open Access Journals (Sweden)

    Bireswar Laha

    2016-09-01

    Full Text Available Analysis of raw volume data generated from different scanning technologies faces a variety of challenges, related to search, pattern recognition, spatial understanding, quantitative estimation, and shape description. In a previous study, we found that the Volume Cracker (VC 3D interaction (3DI technique mitigated some of these problems, but this result was from a tethered glove-based system with users analyzing simulated data. Here, we redesigned the VC by using untethered bare-hand interaction with real volume datasets, with a broader aim of adoption of this technique in research labs. We developed symmetric and asymmetric interfaces for the Bare-Hand Volume Cracker (BHVC through design iterations with a biomechanics scientist. We evaluated our asymmetric BHVC technique against standard 2D and widely used 3D interaction techniques with experts analyzing scanned beetle datasets. We found that our BHVC design significantly outperformed the other two techniques. This study contributes a practical 3DI design for scientists, documents lessons learned while redesigning for bare-hand trackers, and provides evidence suggesting that 3D interaction could improve volume data analysis for a variety of visual analysis tasks. Our contribution is in the realm of 3D user interfaces tightly integrated with visualization, for improving the effectiveness of visual analysis of volume datasets. Based on our experience, we also provide some insights into hardware-agnostic principles for design of effective interaction techniques.

  2. Volume Regulated Channels

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjær

    of volume perturbations evolution have developed system of channels and transporters to tightly control volume homeostasis. In the past decades evidence has been mounting, that the importance of these volume regulated channels and transporters are not restricted to the defense of cellular volume...... but are also essential for a number of physiological processes such as proliferation, controlled cell death, migration and endocrinology. The thesis have been focusing on two Channels, namely the swelling activated Cl- channel (ICl, swell) and the transient receptor potential Vanilloid (TRPV4) channel. I: Cl......- serves a multitude of functions in the mammalian cell, regulating the membrane potential (Em), cell volume, protein activity and the driving force for facilitated transporters giving Cl- and Cl- channels a major potential of regulating cellular function. These functions include control of the cell cycle...

  3. Volume-Dependent Overestimation of Spontaneous Intracerebral Hematoma Volume by the ABC/2 Formula

    International Nuclear Information System (INIS)

    Chih-Wei Wang; Chun-Jung Juan; Hsian-He Hsu; Hua-Shan Liu; Cheng-Yu Chen; Chun-Jen Hsueh; Hung-Wen Kao; Guo-Shu Huang; Yi-Jui Liu; Chung-Ping Lo

    2009-01-01

    Background: Although the ABC/2 formula has been widely used to estimate the volume of intracerebral hematoma (ICH), the formula tends to overestimate hematoma volume. The volume-related imprecision of the ABC/2 formula has not been documented quantitatively. Purpose: To investigate the volume-dependent overestimation of the ABC/2 formula by comparing it with computer-assisted volumetric analysis (CAVA). Material and Methods: Forty patients who had suffered spontaneous ICH and who had undergone non-enhanced brain computed tomography scans were enrolled in this study. The ICH volume was estimated based on the ABC/2 formula and also calculated by CAVA. Based on the ICH volume calculated by the CAVA method, the patients were divided into three groups: group 1 consisted of 17 patients with an ICH volume of less than 20 ml; group 2 comprised 13 patients with an ICH volume of 20 to 40 ml; and group 3 was composed of 10 patients with an ICH volume larger than 40 ml. Results: The mean estimated hematoma volume was 43.6 ml when using the ABC/2 formula, compared with 33.8 ml when using the CAVA method. The mean estimated difference was 1.3 ml, 4.4 ml, and 31.4 ml for groups 1, 2, and 3, respectively, corresponding to an estimation error of 9.9%, 16.7%, and 37.1% by the ABC/2 formula (P<0.05). Conclusion: The ABC/2 formula significantly overestimates the volume of ICH. A positive association between the estimation error and the volume of ICH is demonstrated

  4. Waste volume reduction by spray drying

    Energy Technology Data Exchange (ETDEWEB)

    Toscano, Rodrigo A.; Tello, Clédola C. O. de, E-mail: Rodrigotoscano1@gmail.com, E-mail: tellocc@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    The operation of nuclear facilities generates liquid wastes which require treatment to control the chemical compounds and removal of radioactive contaminants. These wastes can come from the cooling of the primary reactor system, from the reactor pool decontamination, washing of contaminated clothing, among others. The ion exchange resin constitutes the largest fraction of this waste, classified as low and intermediate level of radiation. According to CNEN Standard 8.01, the minimization of the volume and activity of the radioactive waste generated in the operation of a nuclear installation, radiative installation, industrial mining installation or radioactive waste deposit should be ensured. In addition, one of the acceptance criteria for wastes in repositories required by CNEN NN 6.09 is that it be solid or solidified. Thus, these wastes must be reduced in volume and solidified to meet the standards and the safety of the population and the environment. The objective of this work is to find a solution that associates the least generation of packaged waste and the acceptance criteria of waste for the deposition in the national repository. This work presents a proposal of reduction of the volume of the liquid wastes generated by nuclear facilities by drying by for reduction of volume for a greater incorporation of wastes in cement. Using spray dryer, an 18% reduction in the production of cemented waste products was observed in relation to the method currently used with compressive strength measurement above the standard, and it is believed that this value may increase in future tests. (author)

  5. Waste volume reduction by spray drying

    International Nuclear Information System (INIS)

    Toscano, Rodrigo A.; Tello, Clédola C. O. de

    2017-01-01

    The operation of nuclear facilities generates liquid wastes which require treatment to control the chemical compounds and removal of radioactive contaminants. These wastes can come from the cooling of the primary reactor system, from the reactor pool decontamination, washing of contaminated clothing, among others. The ion exchange resin constitutes the largest fraction of this waste, classified as low and intermediate level of radiation. According to CNEN Standard 8.01, the minimization of the volume and activity of the radioactive waste generated in the operation of a nuclear installation, radiative installation, industrial mining installation or radioactive waste deposit should be ensured. In addition, one of the acceptance criteria for wastes in repositories required by CNEN NN 6.09 is that it be solid or solidified. Thus, these wastes must be reduced in volume and solidified to meet the standards and the safety of the population and the environment. The objective of this work is to find a solution that associates the least generation of packaged waste and the acceptance criteria of waste for the deposition in the national repository. This work presents a proposal of reduction of the volume of the liquid wastes generated by nuclear facilities by drying by for reduction of volume for a greater incorporation of wastes in cement. Using spray dryer, an 18% reduction in the production of cemented waste products was observed in relation to the method currently used with compressive strength measurement above the standard, and it is believed that this value may increase in future tests. (author)

  6. Do new anesthesia ventilators deliver small tidal volumes accurately during volume-controlled ventilation?

    Science.gov (United States)

    Bachiller, Patricia R; McDonough, Joseph M; Feldman, Jeffrey M

    2008-05-01

    During mechanical ventilation of infants and neonates, small changes in tidal volume may lead to hypo- or hyperventilation, barotrauma, or volutrauma. Partly because breathing circuit compliance and fresh gas flow affect tidal volume delivery by traditional anesthesia ventilators in volume-controlled ventilation (VCV) mode, pressure-controlled ventilation (PCV) using a circle breathing system has become a common approach to minimizing the risk of mechanical ventilation for small patients, although delivered tidal volume is not assured during PCV. A new generation of anesthesia machine ventilators addresses the problems of VCV by adjusting for fresh gas flow and for the compliance of the breathing circuit. In this study, we evaluated the accuracy of new anesthesia ventilators to deliver small tidal volumes. Four anesthesia ventilator systems were evaluated to determine the accuracy of volume delivery to the airway during VCV at tidal volume settings of 100, 200, and 500 mL under different conditions of breathing circuit compliance (fully extended and fully contracted circuits) and lung compliance. A mechanical test lung (adult and infant) was used to simulate lung compliances ranging from 0.0025 to 0.03 L/cm H(2)O. Volumes and pressures were measured using a calibrated screen pneumotachograph and custom software. We tested the Smartvent 7900, Avance, and Aisys anesthesia ventilator systems (GE Healthcare, Madison, WI) and the Apollo anesthesia ventilator (Draeger Medical, Telford, PA). The Smartvent 7900 and Avance ventilators use inspiratory flow sensors to control the volume delivered, whereas the Aisys and Apollo ventilators compensate for the compliance of the circuit. We found that the anesthesia ventilators that use compliance compensation (Aisys and Apollo) accurately delivered both large and small tidal volumes to the airway of the test lung under conditions of normal and low lung compliance during VCV (ranging from 95.5% to 106.2% of the set tidal volume

  7. Helium-induced blistering and volume swelling in nickel

    International Nuclear Information System (INIS)

    Fenske, G.R.

    1979-01-01

    The results of an experimental investigation of He-induced blistering are presented. The mechanisms involved in blistering were examined by observing the microstructure of the implanted region using TEM. The volume swelling was measured as a function of the implant depth. The investigation revealed factors important in understanding the mechanisms involved in blister formation. First, a direct comparison of measured skin-thicknesses with the location of the maximum volume swelling demonstrated that the skin separates at the peak swelling depth, not at the end of the swelling profile. Second, an examination of the assumptions that have been used to predict skin-thicknesses revealed that the differences between predicted and measured skin thicknesses at low energies can be attributed to: failure to account for volume swelling in the skin, using a Gaussian approximation to the range profile, or one generated with a Monte-Carlo code, and uncertainties in the electronic stopping powers. Beyond a certain dose, the density of cavities in the peak-swelling region decreased with increasing dose; indicating that cavity coalescence does occur. A calculation of the He concentration required to fracture the load-bearing cross section between the cavities revealed that a sufficient quantity of He was available to generate the required gas pressures. These observations indicate that models based on coalescence followed by gas-driven deformation provide an accurate description of the mechanisms involved in blistering; and they can accurately predict skin thicknesses at low energies

  8. Hospital volume and adverse events following esophageal endoscopic submucosal dissection in Japan.

    Science.gov (United States)

    Odagiri, Hiroyuki; Yasunaga, Hideo; Matsui, Hiroki; Matsui, Shigeru; Fushimi, Kiyohide; Kaise, Mitsuru

    2017-04-01

    Background and study aims  Esophageal endoscopic submucosal dissection (ESD) has gradually acquired popularity as a minimally invasive surgery for early cancers not only in Japan, but also in other countries. However, most reported outcomes have been based on relatively small samples of patients from specialized centers. Therefore, the association between hospital volume and the rate of adverse events following esophageal ESD has been poorly understood. Patients and methods  Using a nationwide administrative database in Japan, we identified patients who underwent esophageal ESD between 1 July 2007 and 31 March 2013. Hospital volume was defined as the number of esophageal ESD procedures performed per year at each hospital and was categorized into quartiles. Results  In total, 12 899 esophageal ESD procedures at 699 institutions were identified during the study period. Perforation and perforation-related disorders were observed in 422 patients (3.3 %), and one patient died after perforation. There was a significant association between a lower hospital volume and a higher proportion of adverse events following esophageal ESD. Although not statistically significant, a similar tendency was observed in the occurrence of blood transfusion within 1 week after ESD and all-cause in-hospital death. Multivariable logistic regression analysis showed that hospitals with very high case volumes were less likely to experience adverse events following esophageal ESD than hospitals with very low volumes. Conclusions  The proportion of perforation and perforation-related disorders following esophageal ESD was permissibly low, and there was a linear association between higher hospital volume and lower rates of adverse events following esophageal ESD. © Georg Thieme Verlag KG Stuttgart · New York.

  9. Spatial variation in void volume during charged particle bombardment: the effects of injected interstitials

    International Nuclear Information System (INIS)

    Lee, E.H.; Mansur, L.K.; Yoo, M.H.

    1979-01-01

    Experimental observations of the void volume at several depths along the range of 4 MeV Ni ions in 316 stainless steel are reported. The specimens were first preconditioned by neutron irradiation at temperatures of 450 and 584 0 C to fluences of approximately 8 x 10 26 n/m -2 . The void volume after ion bombardment to 60 dpa at the peak damage depth is significantly lower at the peak damage depth than in the region between that and the free surface. The ratio of the step height to void volume at the depth of peak energy deposition between regions masked from and exposed to the beam is strongly dependent on bombardment temperature. The reduction of void volume near the peak damage depth is larger for the 584 0 C than for the 450 0 C preconditioned material. These observations are consistent with recent theoretical results which account for the injection of the bombarding ions as self-interstitials. The theory necessary to understand the effect is developed

  10. Finite-volume effects due to spatially non-local operators arXiv

    CERN Document Server

    Briceño, Raúl A.; Hansen, Maxwell T.; Monahan, Christopher J.

    Spatially non-local matrix elements are useful lattice-QCD observables in a variety of contexts, for example in determining hadron structure. To quote credible estimates of the systematic uncertainties in these calculations, one must understand, among other things, the size of the finite-volume effects when such matrix elements are extracted from numerical lattice calculations. In this work, we estimate finite-volume effects for matrix elements of non-local operators, composed of two currents displaced in a spatial direction by a distance $\\xi$. We find that the finite-volume corrections depend on the details of the matrix element. If the external state is the lightest degree of freedom in the theory, e.g.~the pion in QCD, then the volume corrections scale as $ e^{-m_\\pi (L- \\xi)} $, where $m_\\pi$ is the mass of the light state. For heavier external states the usual $e^{- m_\\pi L}$ form is recovered, but with a polynomial prefactor of the form $L^m/|L - \\xi|^n$ that can lead to enhanced volume effects. These ...

  11. Hea haridus alternatiivkoolist? / Tiiu Kuurme

    Index Scriptorium Estoniae

    Kuurme, Tiiu, 1953-

    2000-01-01

    Alternatiivkoolidest ja peamistest suundadest alternatiivpedagoogikas : avatud õpetus, Montessori-pedagoogika, Waldorf- ehk Steiner-pedagoogika, Freinet̀pedagoogika, vabad alternatiivkoolid, Jena-Plaan-pedagoogika, Landschulheim-tüüpi internaatkoolid, kool kui linn

  12. Use of soft data in a GIS to improve estimation of the volume of contaminated soil

    International Nuclear Information System (INIS)

    Hendriks, L.A.M.; Leummens, H.; Stein, A.; Bruijn, P.J. de

    1998-01-01

    In the practice of soil remediation, organoleptic observations such as the smell or the colour of contaminated soil play an important role when determining well-defined volumes of contaminated soil. A geographical information system (GIS) is then used to combine quantitative measurements with such soft data. In this study general procedures concerning how to deal with this type of observation are presented. The procedures were applied to a former gas works site, which was contaminated with cyanide and polycyclic aromatic hydrocarbons in the Netherlands. The volume of contaminated soil was determined. Use of soft data reduced the uncertainty in the volume of contaminated soil 4 to 16%. 16 refs., 4 figs., 5 tabs

  13. Use of soft data in a GIS to improve estimation of the volume of contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Hendriks, L.A.M.; Leummens, H.; Stein, A.; Bruijn, P.J. de [Agricultural University, Wageningen (Netherlands). Dept. of Soil Science and Geology

    1998-01-01

    In the practice of soil remediation, organoleptic observations such as the smell or the colour of contaminated soil play an important role when determining well-defined volumes of contaminated soil. A geographical information system (GIS) is then used to combine quantitative measurements with such soft data. In this study general procedures concerning how to deal with this type of observation are presented. The procedures were applied to a former gas works site, which was contaminated with cyanide and polycyclic aromatic hydrocarbons in the Netherlands. The volume of contaminated soil was determined. Use of soft data reduced the uncertainty in the volume of contaminated soil 4 to 16%. 16 refs., 4 figs., 5 tabs.

  14. Errors of the backextrapolation method in determination of the blood volume

    Science.gov (United States)

    Schröder, T.; Rösler, U.; Frerichs, I.; Hahn, G.; Ennker, J.; Hellige, G.

    1999-01-01

    Backextrapolation is an empirical method to calculate the central volume of distribution (for example the blood volume). It is based on the compartment model, which says that after an injection the substance is distributed instantaneously in the central volume with no time delay. The occurrence of recirculation is not taken into account. The change of concentration with time of indocyanine green (ICG) was observed in an in vitro model, in which the volume was recirculating in 60 s and the clearance of the ICG could be varied. It was found that the higher the elimination of ICG, the higher was the error of the backextrapolation method. The theoretical consideration of Schröder et al ( Biomed. Tech. 42 (1997) 7-11) was proved. If the injected substance is eliminated somewhere in the body (i.e. not by radioactive decay), the backextrapolation method produces large errors.

  15. Estimação do volume de árvores utilizando redes neurais artificiais Estimate of tree volume using artificial neural nets

    Directory of Open Access Journals (Sweden)

    Eric Bastos Gorgens

    2009-12-01

    Full Text Available Rede neural artificial consiste em um conjunto de unidades que contêm funções matemáticas, unidas por pesos. As redes são capazes de aprender, mediante modificação dos pesos sinápticos, e generalizar o aprendizado para outros arquivos desconhecidos. O projeto de redes neurais é composto por três etapas: pré-processamento, processamento e, por fim, pós-processamento dos dados. Um dos problemas clássicos que podem ser abordados por redes é a aproximação de funções. Nesse grupo, pode-se incluir a estimação do volume de árvores. Foram utilizados quatro arquiteturas diferentes, cinco pré-processamentos e duas funções de ativação. As redes que se apresentaram estatisticamente iguais aos dados observados também foram analisadas quanto ao resíduo e à distribuição dos volumes e comparadas com a estimação de volume pelo modelo de Schumacher e Hall. As redes neurais formadas por neurônios, cuja função de ativação era exponencial, apresentaram estimativas estatisticamente iguais aos dados observados. As redes treinadas com os dados normalizados pelo método da interpolação linear e equalizados tiveram melhor desempenho na estimação.The artificial neural network consists of a set of units containing mathematical functions connected by weights. Such nets are capable of learning by means of synaptic weight modification, generalizing learning for other unknown archives. The neural network project comprises three stages: pre-processing, processing and post-processing of data. One of the classical problems approached by networks is function approximation. Tree volume estimate can be included in this group. Four different architectures, five pre-processings and two activation functions were used. The nets which were statistically similar to the observed data were also analyzed in relation to residue and volume and compared to the volume estimate provided by the Schumacher and Hall equation. The neural nets formed by

  16. Determination of adrenal volume by MRI in healthy children

    DEFF Research Database (Denmark)

    Mouritsen, Annette; Johansen, Marie Lindhardt; Wohlfahrt-Veje, Christine

    2014-01-01

    , to estimate adrenal size in healthy children and to evaluate determinants of adrenal volume such as age, gender, body size, pubic hair stage and serum levels of adrenal androgens. DESIGN: Two hundred and thirty-five healthy children (116 girls and 119 boys) (age range 10.0-14.8 years) were examined by MRI......% of healthy children aged 10-15 years. Adrenal volume increased with age and Tanner stage of pubic hair. Future studies will unravel whether adrenal MRI is useful when evaluating children with adrenal diseases....... (estimate B = 0.34 ml/year, P = 0.03), age (estimate B = 0.05 ml/year, P = 0.021) and pubic hair stage (estimate B = 0.05 ml/stage, P = 0.075). No associations between adrenal size and serum levels of adrenal androgens were observed. CONCLUSION: It was possible to determine adrenal volume by MRI in only 50...

  17. Global and regional changes of cardiopulmonary blood volume under continuous work load

    International Nuclear Information System (INIS)

    Hoeck, A.; Schuerch, P.; Freundlieb, C.; Vyska, K.; Kunz, N.; Feinendegen, L.E.; Hollmann, W.

    1980-01-01

    The present study describes a method for the continuous determination of global and regional stress-induced alterations of cardiopulmonary blood volumes in normals, trained athletes and patients with latent cardiac insufficiency. In contrast to normals and athletes there is an increase of the total cardiac blood volume in the cardiac patients. There are also significant differences in blood volume changes of the left lung between normals and athletes on the one hand and the cardiac patients on the other. The method is simple and non-hazardous; it permits the observation of the obviously different adaptation of the cardiopulmonary system during exercise in normals, athletes and cardiac patients. (orig.) [de

  18. Observation of changing crystal orientations during grain coarsening

    International Nuclear Information System (INIS)

    Sharma, Hemant; Huizenga, Richard M.; Bytchkov, Aleksei; Sietsma, Jilt; Offerman, S. Erik

    2012-01-01

    Understanding the underlying mechanisms of grain coarsening is important in controlling the properties of metals, which strongly depend on the microstructure that forms during the production process or during use at high temperature. Grain coarsening of austenite at 1273 K in a binary Fe–2 wt.% Mn alloy was studied using synchrotron radiation. Evolution of the volume, average crystallographic orientation and mosaicity of more than 2000 individual austenite grains was tracked during annealing. It was found that an approximately linear relationship exists between grain size and mosaicity, which means that orientation gradients are present in the grains. The orientation gradients remain constant during coarsening and consequently the character of grain boundaries changes during coarsening, affecting the coarsening rate. Furthermore, changes in the average orientation of grains during coarsening were observed. The changes could be understood by taking the observed orientation gradients and anisotropic movement of grain boundaries into account. Five basic modes of grain coarsening were deduced from the measurements, which include: anisotropic (I) and isotropic (II) growth (or shrinkage); movement of grain boundaries resulting in no change in volume but a change in shape (III); movement of grain boundaries resulting in no change in volume and mosaicity, but a change in crystallographic orientation (IV); no movement of grain boundaries (V).

  19. Reachable volume RRT

    KAUST Repository

    McMahon, Troy

    2015-05-01

    © 2015 IEEE. Reachable volumes are a new technique that allows one to efficiently restrict sampling to feasible/reachable regions of the planning space even for high degree of freedom and highly constrained problems. However, they have so far only been applied to graph-based sampling-based planners. In this paper we develop the methodology to apply reachable volumes to tree-based planners such as Rapidly-Exploring Random Trees (RRTs). In particular, we propose a reachable volume RRT called RVRRT that can solve high degree of freedom problems and problems with constraints. To do so, we develop a reachable volume stepping function, a reachable volume expand function, and a distance metric based on these operations. We also present a reachable volume local planner to ensure that local paths satisfy constraints for methods such as PRMs. We show experimentally that RVRRTs can solve constrained problems with as many as 64 degrees of freedom and unconstrained problems with as many as 134 degrees of freedom. RVRRTs can solve problems more efficiently than existing methods, requiring fewer nodes and collision detection calls. We also show that it is capable of solving difficult problems that existing methods cannot.

  20. Reachable volume RRT

    KAUST Repository

    McMahon, Troy; Thomas, Shawna; Amato, Nancy M.

    2015-01-01

    © 2015 IEEE. Reachable volumes are a new technique that allows one to efficiently restrict sampling to feasible/reachable regions of the planning space even for high degree of freedom and highly constrained problems. However, they have so far only been applied to graph-based sampling-based planners. In this paper we develop the methodology to apply reachable volumes to tree-based planners such as Rapidly-Exploring Random Trees (RRTs). In particular, we propose a reachable volume RRT called RVRRT that can solve high degree of freedom problems and problems with constraints. To do so, we develop a reachable volume stepping function, a reachable volume expand function, and a distance metric based on these operations. We also present a reachable volume local planner to ensure that local paths satisfy constraints for methods such as PRMs. We show experimentally that RVRRTs can solve constrained problems with as many as 64 degrees of freedom and unconstrained problems with as many as 134 degrees of freedom. RVRRTs can solve problems more efficiently than existing methods, requiring fewer nodes and collision detection calls. We also show that it is capable of solving difficult problems that existing methods cannot.

  1. Left ventricular volume measurement in mice by conductance catheter: evaluation and optimization of calibration

    DEFF Research Database (Denmark)

    Nielsen, Jan Møller; Kristiansen, Steen B; Ringgaard, Steffen

    2007-01-01

    in mice (n = 52) with a Millar CC (SPR-839) and compared with MRI-derived volumes (V(MRI)). Significant correlations between V(CC) and V(MRI) [end-diastolic volume (EDV): R(2) = 0.85, P 2) = 0.88, P ... in the pulmonary artery was used to calibrate for parallel conductance and volume conversion was done by individual cylinder calibration. However, a significant underestimation was observed [EDV = -17.3 microl (-22.7 to -11.9 microl); ESV = -8.8 microl (-12.5 to -5.1 microl)]. Intravenous injection....... The dual-frequency method for estimation of parallel conductance failed to produce V(CC) that correlated with V(MRI). We conclude that selection of the calibration procedure for the CC has significant implications for the accuracy and precision of volume estimation and pressure-volume loop...

  2. Ground and Space Radar Volume Matching and Comparison Software

    Science.gov (United States)

    Morris, Kenneth; Schwaller, Mathew

    2010-01-01

    This software enables easy comparison of ground- and space-based radar observations. The software was initially designed to compare ground radar reflectivity from operational, ground based Sand C-band meteorological radars with comparable measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite s Precipitation Radar (PR) instrument. The software is also applicable to other ground-based and space-based radars. The ground and space radar volume matching and comparison software was developed in response to requirements defined by the Ground Validation System (GVS) of Goddard s Global Precipitation Mission (GPM) project. This software innovation is specifically concerned with simplifying the comparison of ground- and spacebased radar measurements for the purpose of GPM algorithm and data product validation. This software is unique in that it provides an operational environment to routinely create comparison products, and uses a direct geometric approach to derive common volumes of space- and ground-based radar data. In this approach, spatially coincident volumes are defined by the intersection of individual space-based Precipitation Radar rays with the each of the conical elevation sweeps of the ground radar. Thus, the resampled volume elements of the space and ground radar reflectivity can be directly compared to one another.

  3. Portal blood flow volume measurement in schistosomal patients: evaluation of Doppler ultrasonography reproducibility

    International Nuclear Information System (INIS)

    Leao, Alberto Ribeiro de Souza; Santos, Jose Eduardo Mourao; Moulin, Danilo Sales; Shigueoka, David Carlos; D'Ippolito, Giuseppe; Colleoni, Ramiro

    2008-01-01

    Objective: To evaluate the reproducibility of Doppler ultrasonography in the measurement of portal blood flow volume in schistosomal patients. Materials and methods: Prospective, transversal, observational and self-paired study evaluating 21 patients with hepatosplenic schistosomiasis submitted to Doppler ultrasonography performed by three independent observers for measurement of portal blood flow. Pairwise interobserver agreement was calculated by means of the intraclass correlation coefficient, paired t-test and Pearson's correlation coefficient. Results: Interobserver agreement was excellent. Intraclass correlation ranged from 80.6% to 93.0% (IC at 95% [65.3% ; 95.8%]), with the Pearson's correlation coefficient ranging between 81.6% and 92.7% with no statistically significant interobserver difference regarding the mean portal blood flow volume measured by Doppler ultrasonography (p = 0.954 / 0.758 / 0.749). Conclusion: Doppler ultrasonography has demonstrated to be a reliable method for measuring the portal blood flow volume in patients with portal hypertension secondary to schistosomiasis, with a good interobserver agreement. (author)

  4. Portal blood flow volume measurement in schistosomal patients: evaluation of Doppler ultrasonography reproducibility

    Energy Technology Data Exchange (ETDEWEB)

    Leao, Alberto Ribeiro de Souza; Santos, Jose Eduardo Mourao; Moulin, Danilo Sales; Shigueoka, David Carlos; D' Ippolito, Giuseppe [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Escola Paulista de Medicina. Dept. de Diagnostico por Imagem]. E-mail: ar.leao@uol.com.br; Colleoni, Ramiro [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Escola Paulista de Medicina. Dept. de Gastroenterologia

    2008-09-15

    Objective: To evaluate the reproducibility of Doppler ultrasonography in the measurement of portal blood flow volume in schistosomal patients. Materials and methods: Prospective, transversal, observational and self-paired study evaluating 21 patients with hepatosplenic schistosomiasis submitted to Doppler ultrasonography performed by three independent observers for measurement of portal blood flow. Pairwise interobserver agreement was calculated by means of the intraclass correlation coefficient, paired t-test and Pearson's correlation coefficient. Results: Interobserver agreement was excellent. Intraclass correlation ranged from 80.6% to 93.0% (IC at 95% [65.3% ; 95.8%]), with the Pearson's correlation coefficient ranging between 81.6% and 92.7% with no statistically significant interobserver difference regarding the mean portal blood flow volume measured by Doppler ultrasonography (p = 0.954 / 0.758 / 0.749). Conclusion: Doppler ultrasonography has demonstrated to be a reliable method for measuring the portal blood flow volume in patients with portal hypertension secondary to schistosomiasis, with a good interobserver agreement. (author)

  5. Dual effect of insulin on plasma volume and transcapillary albumin transport

    DEFF Research Database (Denmark)

    Hilsted, J; Christensen, N J

    1992-01-01

    vascular dilatation and increased muscle sympathetic nerve activity during a euglycaemic glucose clamp. During similar conditions insulin increased the transcapillary escape rate of albumin and reduced plasma volume. Insulin has also an indirect effect on vascular permeability during hypoglycaemia, which...... is mediated by the increase in plasma adrenaline. Adrenaline infusion increased haematocrit and decreased plasma volume and intravascular albumin mass. In contrast to insulin adrenaline did not increase the transcapillary escape rate of albumin. Total autonomic blockade during insulin-induced hypoglycaemia...... abolished the increase in haematocrit, but did not influence the decrease in plasma volume and the increase in the transcapillary escape rate of albumin. Insulin administration may also increase urinary albumin excretion, and this effect was observed during a euglycaemic clamp. The mechanism of the increase...

  6. MRI volume measurement of basal ganglia volumes in patients with Tourette's syndrome

    International Nuclear Information System (INIS)

    Lu Jie; Li Kuncheng; Cao Yanxiang; Zhang Miao; Sui Xin; Zhang Xiaohua

    2009-01-01

    Objective: To evaluate MRI measurement of basal ganglia volumes in patients with Tourette's syndrome. Methods: Ten patients with Tourette's syndrome (TS) and 10 healthy volunteers were studied. Volumes of bilateral caudate, putamen and pallidum were measured, and the results were analyzed using paired t test. The basal ganglia volume was normalized according to individual brain volume. The basal ganglia volumes of TS patients were compared with normal control group using independent-sample t test. Results: In 10 healthy volunteers, volumes of the left caudate, putamen, pallidum were significantly larger compared with those of the right side (P 0.05) in TS patients. After normalized processing, the volumes of the left caudate (7.06 ± 0.48) cm 3 , putamen (8.81±1.01) cm 3 , pallidum (2.64± 0.38) cm 3 were smaller than those of control group [caudate (11.05±1.86) cm 3 , putamen (9.97± 1.11) cm 3 , pallidum (3.04±0.37) cm 3 ] (t=-6.577, -2.457, -2.376, P 3 in TS patients was significantly smaller compared with the control group (9.81±1.83) cm 3 (t=-4.258, P 0.05). Conclusion: The basal ganglia volumes were significantly decreased in patients with TS. MRI volumetric measurement was an important tool for evaluating pathologic changes of TS. (authors)

  7. Volume growth rate of acoustic neurinomas

    International Nuclear Information System (INIS)

    Laasonen, E.M.; Troupp, H.

    1986-01-01

    Of 79 acoustic neurinomas seen between June 1980 and June 1984, at least two CT scans were available for each of 23 tumours (21 patients); the scans were performed at intervals of at least 6 months. The volume growth rate of the tumours was either moderate, with a volume doubling time ranging from 205 to 545 days, or slow, with a doubling time ranging from 1090 days to no observable growth. No single clinical, radiological or histological feature correlated with any type of growth rate. However, some conclusions were drawn. If a primary CT scan is negative, at least 1 year should elapse before it is worthwhile taking another scan, even though audiological findings suggest growth; after an apparently radical removal, at least 3 years should elapse before a check CT scan is worthwhile; and if a small acoustic neurinoma is diagnosed, but for some reason not operated upon, a second CT scan should be carried out 1 year later in order to reassess the case. (orig.)

  8. Experimental determination of the PTW 60019 microDiamond dosimeter active area and volume

    Energy Technology Data Exchange (ETDEWEB)

    Marinelli, Marco, E-mail: marco.marinelli@uniroma2.it; Prestopino, G.; Verona, C.; Verona-Rinati, G. [INFN–Dipartimento di Ingegneria Industriale, Università di Roma “Tor Vergata,” Via del Politecnico 1, Roma 00133 (Italy)

    2016-09-15

    Purpose: Small field output correction factors have been studied by several research groups for the PTW 60019 microDiamond (MD) dosimeter, by comparing the response of such a device with both reference dosimeters and Monte Carlo simulations. A general good agreement is observed for field sizes down to about 1 cm. However, evident inconsistencies can be noticed when comparing some experimental results and Monte Carlo simulations obtained for smaller irradiation fields. This issue was tentatively attributed by some authors to unintentional large variations of the MD active surface area. The aim of the present study is a nondestructive experimental determination of the MD active surface area and active volume. Methods: Ten MD dosimeters, one MD prototype, and three synthetic diamond samples were investigated in the present work. 2D maps of the MD response were recorded under scanned soft x-ray microbeam irradiation, leading to an experimental determination of the device active surface area. Profiles of the device responses were measured as well. In order to evaluate the MD active volume, the thickness of the diamond sensing layer was independently evaluated by capacitance measurements and alpha particle detection experiments. The MD sensitivity, measured at the PTW calibration laboratory, was also used to calculate the device active volume thickness. Results: An average active surface area diameter of (2.19 ± 0.02) mm was evaluated by 2D maps and response profiles of all the MDs. Average active volume thicknesses of (1.01 ± 0.13) μm and (0.97 ± 0.14) μm were derived by capacitance and sensitivity measurements, respectively. The obtained results are well in agreement with the nominal values reported in the manufacturer dosimeter specifications. A homogeneous response was observed over the whole device active area. Besides the one from the device active volume, no contributions from other components of the housing nor from encapsulation materials were observed in

  9. Free volume changes in mechanically milled PS and PC studied by positron annihilation lifetime spectroscopy (PALS)

    NARCIS (Netherlands)

    Günther-Schade, K.; Castricum, H.L.; Ziegler, H.J.; Bakker, H.; Faupel, F.

    2004-01-01

    The effect of mechanical milling on free volume was studied by means of positron annihilation lifetime spectroscopy (PALS) in polystyrene (PS) as a typical brittle polymer and in polycarbonate (PC) as a tough representative. Long-time milling increases the free volume, while a decrease is observed

  10. ORGANIZATIONS AND STRATEGIES IN ASTRONOMY VOLUME 7

    CERN Document Server

    HECK, ANDRÉ

    2006-01-01

    This book is the seventh volume under the title Organizations and Strategies in Astronomy (OSA). The OSA series covers a large range of fields and themes: in practice, one could say that all aspects of astronomy-related life and environment are considered in the spirit of sharing specific expertise and lessons learned. The chapters of this book are dealing with socio-dynamical aspects of the astronomy (and related space sciences) community: characteristics of organizations, strategies for development, operational techniques, observing practicalities, journal and magazine profiles, public outreach, publication studies, relationships with the media, research communication, series of conferences, evaluation and selection procedures, research indicators, national specificities, contemporary history, and so on. The experts contributing to this volume have done their best to write in a way understandable to readers not necessarily hyperspecialized in astronomy while providing specific detailed information and somet...

  11. Organizations and Strategies in Astronomy Volume 6

    CERN Document Server

    Heck, André

    2006-01-01

    This book is the sixth volume under the title Organizations and Strategies in Astronomy (OSA). The OSA series is intended to cover a large range of fields and themes. In practice, one could say that all aspects of astronomy-related life and environment are considered in the spirit of sharing specific expertise and lessons learned. The chapters of this book are dealing with socio-dynamical aspects of the astronomy (and related space sciences) community: characteristics of organizations, strategies for development, legal issues, operational techniques, observing practicalities, educational policies, journal and magazine profiles, public outreach, publication studies, relationships with the media, research communication, evaluation and selection procedures, research indicators, national specificities, contemporary history, and so on. The experts contributing to this volume have done their best to write in a way understandable to readers not necessarily hyperspecialized in astronomy while providing specific detai...

  12. Variability of Gross Tumor Volume in Nasopharyngeal Carcinoma Using 11C-Choline and 18F-FDG PET/CT.

    Directory of Open Access Journals (Sweden)

    Jun Jiang

    Full Text Available This study was conducted to evaluate the variability of gross tumor volume (GTV using 11C-Choline and 18F-FDG PET/CT images for nasopharyngeal carcinomas boundary definition. Assessment consisted of inter-observer and inter-modality variation analysis. Four radiation oncologists were invited to manually contour GTV by using PET/CT fusion obtained from a cohort of 12 patients with nasopharyngeal carcinoma (NPC and who underwent both 11C-Choline and 18F-FDG scans. Student's paired-sample t-test was performed for analyzing inter-observer and inter-modality variability. Semi-automatic segmentation methods, including thresholding and region growing, were also validated against the manual contouring of the two types of PET images. We observed no significant variation in the results obtained by different oncologists in terms of the same type of PET/CT volumes. Choline fusion volumes were significantly larger than the FDG volumes (p < 0.0001, mean ± SD = 18.21 ± 8.19. While significantly consistent results were obtained between the oncologists and the standard references in Choline volumes compared with those in FDG volumes (p = 0.0025. Simple semi-automatic delineation methods indicated that 11C-Choline PET images could provide better results than FDG volumes (p = 0.076, CI = [-0.29, 0.025]. 11C-Choline PET/CT may be more advantageous in GTV delineation for the radiotherapy of NPC than 18F-FDG. Phantom simulations and clinical trials should be conducted to prove the possible improvement of the treatment outcome.

  13. Disorganized Attachment in Infancy Predicts Greater Amygdala Volume in Adulthood

    Science.gov (United States)

    Lyons-Ruth, K.; Pechtel, P.; Yoon, S.A.; Anderson, C.M.; Teicher, M.H.

    2016-01-01

    Early life stress in rodents is associated with increased amygdala volume in adulthood. In humans, the amygdala develops rapidly during the first two years of life. Thus, disturbed care during this period may be particularly important to amygdala development. In the context of a 30-year longitudinal study of impoverished, highly stressed families, we assessed whether disorganization of the attachment relationship in infancy was related to amygdala volume in adulthood. Amygdala volumes were assessed among 18 low-income young adults (8M/10F, 29.33±0.49 years) first observed in infancy (8.5±5.6 months) and followed longitudinally to age 29. In infancy (18.58±1.02 mos), both disorganized infant attachment behavior and disrupted maternal communication were assessed in the standard Strange Situation Procedure (SSP). Increased left amygdala volume in adulthood was associated with both maternal and infant components of disorganized attachment interactions at 18 months of age (overall r = .679, p attachment disturbance in adolescence, were not significantly related to left amygdala volume. Left amygdala volume was further associated with dissociation and limbic irritability in adulthood. Finally, left amygdala volume mediated the prediction from attachment disturbance in infancy to limbic irritability in adulthood. Results point to the likely importance of quality of early care for amygdala development in human children as well as in rodents. The long-term prediction found here suggests that the first two years of life may be an early sensitive period for amygdala development during which clinical intervention could have particularly important consequences for later child outcomes. PMID:27060720

  14. Analysis of the chemical equilibrium of combustion at constant volume

    Directory of Open Access Journals (Sweden)

    Marius BREBENEL

    2014-04-01

    Full Text Available Determining the composition of a mixture of combustion gases at a given temperature is based on chemical equilibrium, when the equilibrium constants are calculated on the assumption of constant pressure and temperature. In this paper, an analysis of changes occurring when combustion takes place at constant volume is presented, deriving a specific formula of the equilibrium constant. The simple reaction of carbon combustion in pure oxygen in both cases (constant pressure and constant volume is next considered as example of application, observing the changes occurring in the composition of the combustion gases depending on temperature.

  15. Radionuclide determined pulmonary blood volume in ischaemic heart disease

    International Nuclear Information System (INIS)

    Hannan, W.J.; Vojacek, J.; Connell, H.M. Dewhurst N.G.; Muir, A.L.

    1981-01-01

    Most measurements of pulmonary blood volume have been based on the Stewart-Hamilton dye dilution principle and have required direct catheterisation of the cardiac chambers. Alternatively a precordial counter may be used to detect the composite right and left heart curves after an intravenous injection of radionuclide. We investigated the use of a gamma camera/computer system to determine the radionuclide (sup(99m)Tc) dilution curves from individual cardiac chambers. Pulmonary transit time and pulmonary blood volume were measured in nine normal subjects, eight patients with angina pectoris but without heart failure, and 13 patients with ischaemic heart disease and left ventricular failure. Patients with heart failure had significantly greater (p 0 angle. A reduction in pulmonary blood volume in the tilted position was observed in each subject (p < 0.005). This simple non-invasive measurement should allow more detailed assessment of physiological or pharmacological changes of the pulmonary vascular bed. (author)

  16. Mechanical homeostasis regulating adipose tissue volume

    Directory of Open Access Journals (Sweden)

    Svedman Paul

    2007-09-01

    Full Text Available Abstract Background The total body adipose tissue volume is regulated by hormonal, nutritional, paracrine, neuronal and genetic control signals, as well as components of cell-cell or cell-matrix interactions. There are no known locally acting homeostatic mechanisms by which growing adipose tissue might adapt its volume. Presentation of the hypothesis Mechanosensitivity has been demonstrated by mesenchymal cells in tissue culture. Adipocyte differentiation has been shown to be inhibited by stretching in vitro, and a pathway for the response has been elucidated. In humans, intermittent stretching of skin for reconstructional purposes leads to thinning of adipose tissue and thickening of epidermis – findings matching those observed in vitro in response to mechanical stimuli. Furthermore, protracted suspension of one leg increases the intermuscular adipose tissue volume of the limb. These findings may indicate a local homeostatic adipose tissue volume-regulating mechanism based on movement-induced reduction of adipocyte differentiation. This function might, during evolution, have been of importance in confined spaces, where overgrowth of adipose tissue could lead to functional disturbance, as for instance in the turtle. In humans, adipose tissue near muscle might in particular be affected, for instance intermuscularly, extraperitoneally and epicardially. Mechanical homeostasis might also contribute to protracted maintainment of soft tissue shape in the face and neck region. Testing of the hypothesis Assessment of messenger RNA-expression of human adipocytes following activity in adjacent muscle is planned, and study of biochemical and volumetric adipose tissue changes in man are proposed. Implications of the hypothesis The interpretation of metabolic disturbances by means of adipose tissue might be influenced. Possible applications in the head and neck were discussed.

  17. Statistical analysis of rockfall volume distributions: Implications for rockfall dynamics

    Science.gov (United States)

    Dussauge, Carine; Grasso, Jean-Robert; Helmstetter, AgnèS.

    2003-06-01

    We analyze the volume distribution of natural rockfalls on different geological settings (i.e., calcareous cliffs in the French Alps, Grenoble area, and granite Yosemite cliffs, California Sierra) and different volume ranges (i.e., regional and worldwide catalogs). Contrary to previous studies that included several types of landslides, we restrict our analysis to rockfall sources which originated on subvertical cliffs. For the three data sets, we find that the rockfall volumes follow a power law distribution with a similar exponent value, within error bars. This power law distribution was also proposed for rockfall volumes that occurred along road cuts. All these results argue for a recurrent power law distribution of rockfall volumes on subvertical cliffs, for a large range of rockfall sizes (102-1010 m3), regardless of the geological settings and of the preexisting geometry of fracture patterns that are drastically different on the three studied areas. The power law distribution for rockfall volumes could emerge from two types of processes. First, the observed power law distribution of rockfall volumes is similar to the one reported for both fragmentation experiments and fragmentation models. This argues for the geometry of rock mass fragment sizes to possibly control the rockfall volumes. This way neither cascade nor avalanche processes would influence the rockfall volume distribution. Second, without any requirement of scale-invariant quenched heterogeneity patterns, the rock mass dynamics can arise from avalanche processes driven by fluctuations of the rock mass properties, e.g., cohesion or friction angle. This model may also explain the power law distribution reported for landslides involving unconsolidated materials. We find that the exponent values of rockfall volume on subvertical cliffs, 0.5 ± 0.2, is significantly smaller than the 1.2 ± 0.3 value reported for mixed landslide types. This change of exponents can be driven by the material strength, which

  18. Molecular representation of molar domain (volume), evolution equations, and linear constitutive relations for volume transport.

    Science.gov (United States)

    Eu, Byung Chan

    2008-09-07

    In the traditional theories of irreversible thermodynamics and fluid mechanics, the specific volume and molar volume have been interchangeably used for pure fluids, but in this work we show that they should be distinguished from each other and given distinctive statistical mechanical representations. In this paper, we present a general formula for the statistical mechanical representation of molecular domain (volume or space) by using the Voronoi volume and its mean value that may be regarded as molar domain (volume) and also the statistical mechanical representation of volume flux. By using their statistical mechanical formulas, the evolution equations of volume transport are derived from the generalized Boltzmann equation of fluids. Approximate solutions of the evolution equations of volume transport provides kinetic theory formulas for the molecular domain, the constitutive equations for molar domain (volume) and volume flux, and the dissipation of energy associated with volume transport. Together with the constitutive equation for the mean velocity of the fluid obtained in a previous paper, the evolution equations for volume transport not only shed a fresh light on, and insight into, irreversible phenomena in fluids but also can be applied to study fluid flow problems in a manner hitherto unavailable in fluid dynamics and irreversible thermodynamics. Their roles in the generalized hydrodynamics will be considered in the sequel.

  19. Observation of Multiple Volume Reflection of Ultrarelativistic Protons by a Sequence of Several Bent Silicon Crystals

    CERN Document Server

    Scandale, Walter; Baricordi, S; Dalpiaz, P; Fiorini, M; Guidi, V; Mazzolari, A; Della Mea, G; Milan, R; Ambrosi, G; Zuccon, P; Bertucci, B; Bürger, W; Duranti, M; Cavoto, G; Santacesaria, R; Valente, P; Luci, C; Iacoangeli, F; Vallazza, E; Afonin, A G; Chesnokov, Yu A; Kotov, V I; Maisheev, V A; Yazynin, I A; Kovalenko, A D; Taratin, A M; Denisov, A S; Gavrikov, Y A; Ivanov, Yu M; Lapina, L P; Malyarenko, L G; Skorogobogatov, V V; Suvorov, V M; Vavilov, S A; Bolognini, D; Hasan, S; Mozzanica, A; Prest, M

    2009-01-01

    The interactions of 400 GeV protons with different sequences of bent silicon crystals have been investigated at the H8 beam line of the CERN Super Proton Synchrotron. The multiple volume reflection of the proton beam has been studied in detail on a five-crystal reflector measuring an angular beam deflection =52.96±0.14 µrad. The efficiency was found larger than 80% for an angular acceptance at the reflector entrance of 70 µrad, with a maximal efficiency value of =0.90±0.01±0.03.

  20. The effect of hospital volume on patient outcomes in severe acute pancreatitis

    Directory of Open Access Journals (Sweden)

    Shen Hsiu-Nien

    2012-08-01

    Full Text Available Abstract Background We investigated the relation between hospital volume and outcome in patients with severe acute pancreatitis (SAP. The determination is important because patient outcome may be improved through volume-based selective referral. Methods In this cohort study, we analyzed 22,551 SAP patients in 2,208 hospital-years (between 2000 and 2009 from Taiwan’s National Health Insurance Research Database. Primary outcome was hospital mortality. Secondary outcomes were hospital length of stay and charges. Hospital SAP volume was measured both as categorical and as continuous variables (per one case increase each hospital-year. The effect was assessed using multivariable logistic regression models with generalized estimating equations accounting for hospital clustering effect. Adjusted covariates included patient and hospital characteristics (model 1, and additional treatment variables (model 2. Results Irrespective of the measurements, increasing hospital volume was associated with reduced risk of hospital mortality after adjusting the patient and hospital characteristics (adjusted odds ratio [OR] 0.995, 95% confidence interval [CI] 0.993-0.998 for per one case increase. The patients treated in the highest volume quartile (≥14 cases per hospital-year had 42% lower risk of hospital mortality than those in the lowest volume quartile (1 case per hospital-year after adjusting the patient and hospital characteristics (adjusted OR 0.58, 95% CI 0.40-0.83. However, an inverse relation between volume and hospital stay or hospital charges was observed only when the volume was analyzed as a categorical variable. After adjusting the treatment covariates, the volume effect on hospital mortality disappeared regardless of the volume measures. Conclusions These findings support the use of volume-based selective referral for patients with SAP and suggest that differences in levels or processes of care among hospitals may have contributed to the volume

  1. Limiting volume with modern ventilators.

    Science.gov (United States)

    Wing, Thomas J; Haan, Lutana; Ashworth, Lonny J; Anderson, Jeff

    2015-06-01

    The acute respiratory distress syndrome (ARDS) network low tidal-volume study comparing tidal volumes of 12 ml/kg versus 6 ml/kg was published in 2000. The study was stopped early as data revealed a 22% relative reduction in mortality rate when using 6 ml/kg tidal volume. The current generation of critical care ventilators allows the tidal volume to be set during volume-targeted, assist/control (volume A/C); however, some ventilators include options that may prevent the tidal volume from being controlled. The purpose of this bench study was to evaluate the delivered tidal volume, when these options are active, in a spontaneously breathing lung model using an electronic breathing simulator. Four ventilators were evaluated: CareFusion AVEA (AVEA), Dräger Evita® XL (Evita XL), Covidien Puritan Bennett® 840(TM) (PB 840), and Maquet SERVO-i (SERVO-i). Each ventilator was connected to the Hans Rudolph Electronic Breathing Simulator at an amplitude of 0 cm H2O and then 10 cm H2O. All four ventilators were set to deliver volume A/C, tidal volume 400 ml, respiratory rate 20 bpm, positive end-expiratory pressure 5 cm H2O, peak flowrate 60 L/min. The displayed tidal volume was recorded for each ventilator at the above settings with additional options OFF and then ON. The AVEA has two options in volume A/C: demand breaths and V-sync. When activated, these options allow the patient to exceed the set tidal volume. When using the Evita XL, the option AutoFlow can be turned ON or OFF, and when this option is ON, the tidal volume may vary. The PB 840 does not have any additional options that affect volume delivery, and it maintains the set tidal volume regardless of patient effort. The SERVO-i's demand valve allows additional flow if the patient's inspiratory flowrate exceeds the set flowrate, increasing the delivered tidal volume; this option can be turned OFF with the latest software upgrade. Modern ventilators have an increasing number of optional settings. These settings may

  2. Noninvasive pulse pressure variation and stroke volume variation to predict fluid responsiveness at multiple thresholds : a prospective observational study

    NARCIS (Netherlands)

    Vos, Jaap Jan; Poterman, Marieke; Papineau Salm, Pieternel; Van Amsterdam, Kai; Struys, Michel M. R. F.; Scheeren, Thomas W. L.; Kalmar, Alain F.

    2015-01-01

    Pulse pressure variation (PPV) and stroke volume variation (SVV) are dynamic preload variables that can be measured noninvasively to assess fluid responsiveness (FR) in anesthetized patients with mechanical ventilation. Few studies have examined the effectiveness of predicting FR according to the

  3. Smaller hippocampal volume as a vulnerability factor for the persistence of post-traumatic stress disorder.

    Science.gov (United States)

    van Rooij, S J H; Kennis, M; Sjouwerman, R; van den Heuvel, M P; Kahn, R S; Geuze, E

    2015-10-01

    Smaller hippocampal volume has often been observed in patients with post-traumatic stress disorder (PTSD). However, there is no consensus whether this is a result of stress/trauma exposure, or constitutes a vulnerability factor for the development of PTSD. Second, it is unclear whether hippocampal volume normalizes with successful treatment of PTSD, or whether a smaller hippocampus is a risk factor for the persistence of PTSD. Magnetic resonance imaging (MRI) scans and clinical interviews were collected from 47 war veterans with PTSD, 25 healthy war veterans (combat controls) and 25 healthy non-military controls. All veterans were scanned a second time with a 6- to 8-month interval, during which PTSD patients received trauma-focused therapy. Based on post-treatment PTSD symptoms, patients were divided into a PTSD group who was in remission (n = 22) and a group in whom PTSD symptoms persisted (n = 22). MRI data were analysed with Freesurfer. Smaller left hippocampal volume was observed in PTSD patients compared with both control groups. Hippocampal volume of the combat controls did not differ from healthy controls. Second, pre- and post-treatment analyses of the PTSD patients and combat controls revealed reduced (left) hippocampal volume only in the persistent patients at both time points. Importantly, hippocampal volume did not change with treatment. Our findings suggest that a smaller (left) hippocampus is not the result of stress/trauma exposure. Furthermore, hippocampal volume does not increase with successful treatment. Instead, we demonstrate for the first time that a smaller (left) hippocampus constitutes a risk factor for the persistence of PTSD.

  4. Target volume delineation variation in radiotherapy for early stage rectal cancer in the Netherlands

    International Nuclear Information System (INIS)

    Nijkamp, Jasper; Haas-Kock, Danielle F.M. de; Beukema, Jannet C.; Neelis, Karen J.; Woutersen, Dankert; Ceha, Heleen; Rozema, Tom; Slot, Annerie; Vos-Westerman, Hanneke; Intven, Martijn; Spruit, Patty H.; Linden, Yvette van der; Geijsen, Debby; Verschueren, Karijn; Herk, Marcel B. van; Marijnen, Corrie A.M.

    2012-01-01

    Purpose: The aim of this study was to measure and improve the quality of target volume delineation by means of national consensus on target volume definition in early-stage rectal cancer. Methods and materials: The CTV’s for eight patients were delineated by 11 radiation oncologists in 10 institutes according to local guidelines (phase 1). After observer variation analysis a workshop was organized to establish delineation guidelines and a digital atlas, with which the same observers re-delineated the dataset (phase 2). Variation in volume, most caudal and cranial slice and local surface distance variation were analyzed. Results: The average delineated CTV volume decreased from 620 to 460 cc (p < 0.001) in phase 2. Variation in the caudal CTV border was reduced significantly from 1.8 to 1.2 cm SD (p = 0.01), while it remained 0.7 cm SD for the cranial border. The local surface distance variation (cm SD) reduced from 1.02 to 0.74 for anterior, 0.63 to 0.54 for lateral, 0.33 to 0.25 for posterior and 1.22 to 0.46 for the sphincter region, respectively. Conclusions: The large variation in target volume delineation could significantly be reduced by use of consensus guidelines and a digital delineation atlas. Despite the significant reduction there is still a need for further improvement.

  5. [Failure of static pulmonary volume measurements in mucoviscidosis].

    Science.gov (United States)

    Haluszka, J; Zebrak, J

    1984-01-01

    With worsening of bronchial obstruction during the course of cystic fibrosis the functional residual capacity (CRF) measured by plethysmography increases progressively. The difference between values of CRF obtained by plethysmography or by Helium dilution increases even more. The difference between the two methods (for CRF) is supposed to show the volume of "trapped"' gas. A similar outcome, although less marked, is observed after physiotherapy. The extent of pulmonary distention and gas trapping is markedly overestimated by plethysmographic measurements, when one considers the anatomical and radiological anomalies. It was recently suggested that the rise in compliance of the walls of the extra-thoracic airways in the presence of bronchial obstruction may lead to an over-estimation of the pulmonary volumes measured by plethysmography. This may be the case during the course of mucoviscidosis, when repeated infections lead to a destruction of the bronchial walls. However, this anomaly does not explain this rise in CRF after mucolytic treatment and postural drainage. The CRF seems to reflect not only the volume of trapper gas in the lung, but equally the failure to equalize the interior pressures of the obstructed airways. In order to appreciate the effects of respiratory physiotherapy, different methods of measuring pulmonary volumes are necessary but the interpretation of the results take account of the complex meterology.

  6. Burnham's celestial handbook. An observer's guide to the universe beyond the solar system. Volume 3. Pavo through Vulpecula

    International Nuclear Information System (INIS)

    Burnham, R. Jr.

    1978-01-01

    This volume of the Celestial Handbook treats the constellations alphabetically from Pavo through Vulpecula. For each it lists double and multiple stars, variable stars, and star clusters, nebulae, and galaxies with positions, magnitudes, etc. It also presents descriptive notes concerning some of the objects; these include history, mythology, and poetical allusions, as well as scientific information

  7. Estimating traffic volume on Wyoming low volume roads using linear and logistic regression methods

    Directory of Open Access Journals (Sweden)

    Dick Apronti

    2016-12-01

    Full Text Available Traffic volume is an important parameter in most transportation planning applications. Low volume roads make up about 69% of road miles in the United States. Estimating traffic on the low volume roads is a cost-effective alternative to taking traffic counts. This is because traditional traffic counts are expensive and impractical for low priority roads. The purpose of this paper is to present the development of two alternative means of cost-effectively estimating traffic volumes for low volume roads in Wyoming and to make recommendations for their implementation. The study methodology involves reviewing existing studies, identifying data sources, and carrying out the model development. The utility of the models developed were then verified by comparing actual traffic volumes to those predicted by the model. The study resulted in two regression models that are inexpensive and easy to implement. The first regression model was a linear regression model that utilized pavement type, access to highways, predominant land use types, and population to estimate traffic volume. In verifying the model, an R2 value of 0.64 and a root mean square error of 73.4% were obtained. The second model was a logistic regression model that identified the level of traffic on roads using five thresholds or levels. The logistic regression model was verified by estimating traffic volume thresholds and determining the percentage of roads that were accurately classified as belonging to the given thresholds. For the five thresholds, the percentage of roads classified correctly ranged from 79% to 88%. In conclusion, the verification of the models indicated both model types to be useful for accurate and cost-effective estimation of traffic volumes for low volume Wyoming roads. The models developed were recommended for use in traffic volume estimations for low volume roads in pavement management and environmental impact assessment studies.

  8. Clinical target volume delineation in glioblastomas: pre-operative versus post-operative/pre-radiotherapy MRI

    Science.gov (United States)

    Farace, P; Giri, M G; Meliadò, G; Amelio, D; Widesott, L; Ricciardi, G K; Dall'Oglio, S; Rizzotti, A; Sbarbati, A; Beltramello, A; Maluta, S; Amichetti, M

    2011-01-01

    Objectives Delineation of clinical target volume (CTV) is still controversial in glioblastomas. In order to assess the differences in volume and shape of the radiotherapy target, the use of pre-operative vs post-operative/pre-radiotherapy T1 and T2 weighted MRI was compared. Methods 4 CTVs were delineated in 24 patients pre-operatively and post-operatively using T1 contrast-enhanced (T1PRECTV and T1POSTCTV) and T2 weighted images (T2PRECTV and T2POSTCTV). Pre-operative MRI examinations were performed the day before surgery, whereas post-operative examinations were acquired 1 month after surgery and before chemoradiation. A concordance index (CI) was defined as the ratio between the overlapping and composite volumes. Results The volumes of T1PRECTV and T1POSTCTV were not statistically different (248 ± 88 vs 254 ± 101), although volume differences >100 cm3 were observed in 6 out of 24 patients. A marked increase due to tumour progression was shown in three patients. Three patients showed a decrease because of a reduced mass effect. A significant reduction occurred between pre-operative and post-operative T2 volumes (139 ± 68 vs 78 ± 59). Lack of concordance was observed between T1PRECTV and T1POSTCTV (CI = 0.67 ± 0.09), T2PRECTV and T2POSTCTV (CI = 0.39 ± 0.20) and comparing the portion of the T1PRECTV and T1POSTCTV not covered by that defined on T2PRECTV images (CI = 0.45 ± 0.16 and 0.44 ± 0.17, respectively). Conclusion Using T2 MRI, huge variations can be observed in peritumoural oedema, which are probably due to steroid treatment. Using T1 MRI, brain shifts after surgery and possible progressive enhancing lesions produce substantial differences in CTVs. Our data support the use of post-operative/pre-radiotherapy T1 weighted MRI for planning purposes. PMID:21045069

  9. Against Better Knowledge: The Magical Force of Amodal Volume Completion

    Directory of Open Access Journals (Sweden)

    Vebjørn Ekroll

    2013-12-01

    Full Text Available In a popular magic routine known as “multiplying billiard balls”, magicians fool their audience by using an empty shell that the audience believes to be a complete ball. Here, we present some observations suggesting that the spectators do not merely entertain the intellectual belief that the balls are all solid, but rather automatically and immediately perceive them as such. Our observations demonstrate the surprising potency and genuinely perceptual origin of amodal volume completion.

  10. Correction volumes and densities in Vitrea Program

    International Nuclear Information System (INIS)

    Abrantes, Marcos E.S.; Oliveira, A.H. de

    2014-01-01

    Introduction: with the increased use of 3D reconstruction techniques to assist in diagnosis, Vitrea® program is widely used. To use this program you need to know the correction values to generate the volumes and number of real CT human tissues. Objective: provide correction values for volumes and number of CT, read the Vitrea program, of the tissues generated by DICOM images from CT. Methodology: this study used a PMMA chest phantom to generate the DICOM images on a scanner. To check the calibration of the scanner was used Catphan phantom and compared the manufacturer of the values associated with its straight linearity. Results: the volume of PMMA phantom was of 11166.58 cm³ and CT number (123.5 ± 33.4) UH. For the volume found in Vitrea program, according to the structures of interest, were 11897.29 cm 3 , 10901.65 cm³, 16906.49 cm 3 and 11848.34 cm³ and corrections values are -6.14%, + 2.43% -6.94% -5.75% respectively for the tissues: lung, bone, soft and full. For the CT numbers found in this program were (97.60 ± 58.9) UH, (72.00 ± 176.00) UH, (143.20 ± 19.50) UH and (31.90 ± 239,10) UH and corrections of + 26.54%, + 71.53%, -13.64% and 387.15% respectively for tissues: lung, bone, soft and full. Conclusion: the procedure performed can be used in other 3D reconstruction programs and where there are tools to reading CT number, observing the necessary corrections

  11. Multi-Hadron Observables from Lattice Quantum Chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Maxwell [Univ. of Washington, Seattle, WA (United States)

    2014-01-01

    We describe formal work that relates the nite-volume spectrum in a quantum eld theory to scattering and decay amplitudes. This is of particular relevance to numerical calculations performed using Lattice Quantum Chromodynamics (LQCD). Correlators calculated using LQCD can only be determined on the Euclidean time axis. For this reason the standard method of determining scattering amplitudes via the Lehmann-Symanzik-Zimmermann reduction formula cannot be employed. By contrast, the nite-volume spectrum is directly accessible in LQCD calculations. Formalism for relating the spectrum to physical scattering observables is thus highly desirable. In this thesis we develop tools for extracting physical information from LQCD for four types of observables. First we analyze systems with multiple, strongly-coupled two-scalar channels. Here we accommodate both identical and nonidentical scalars, and in the latter case allow for degenerate as well as nondegenerate particle masses. Using relativistic eld theory, and summing to all orders in perturbation theory, we derive a result relating the nite-volume spectrum to the two-to-two scattering amplitudes of the coupled-channel theory. This generalizes the formalism of Martin L uscher for the case of single-channel scattering. Second we consider the weak decay of a single particle into multiple, coupled two-scalar channels. We show how the nite-volume matrix element extracted in LQCD is related to matrix elements of asymptotic two-particle states, and thus to decay amplitudes. This generalizes work by Laurent Lellouch and Martin L uscher. Third we extend the method for extracting matrix elements by considering currents which insert energy, momentum and angular momentum. This allows one to extract transition matrix elements and form factors from LQCD. Finally we look beyond two-particle systems to those with three-particles in asymptotic states. Working again to all orders in relativistic eld theory, we derive a relation between the

  12. Regional volumes and spatial volumetric distribution of gray matter in the gender dysphoric brain.

    Science.gov (United States)

    Hoekzema, Elseline; Schagen, Sebastian E E; Kreukels, Baudewijntje P C; Veltman, Dick J; Cohen-Kettenis, Peggy T; Delemarre-van de Waal, Henriette; Bakker, Julie

    2015-05-01

    The sexual differentiation of the brain is primarily driven by gonadal hormones during fetal development. Leading theories on the etiology of gender dysphoria (GD) involve deviations herein. To examine whether there are signs of a sex-atypical brain development in GD, we quantified regional neural gray matter (GM) volumes in 55 female-to-male and 38 male-to-female adolescents, 44 boys and 52 girls without GD and applied both univariate and multivariate analyses. In girls, more GM volume was observed in the left superior medial frontal cortex, while boys had more volume in the bilateral superior posterior hemispheres of the cerebellum and the hypothalamus. Regarding the GD groups, at whole-brain level they differed only from individuals sharing their gender identity but not from their natal sex. Accordingly, using multivariate pattern recognition analyses, the GD groups could more accurately be automatically discriminated from individuals sharing their gender identity than those sharing their natal sex based on spatially distributed GM patterns. However, region of interest analyses indicated less GM volume in the right cerebellum and more volume in the medial frontal cortex in female-to-males in comparison to girls without GD, while male-to-females had less volume in the bilateral cerebellum and hypothalamus than natal boys. Deviations from the natal sex within sexually dimorphic structures were also observed in the untreated subsamples. Our findings thus indicate that GM distribution and regional volumes in GD adolescents are largely in accordance with their respective natal sex. However, there are subtle deviations from the natal sex in sexually dimorphic structures, which can represent signs of a partial sex-atypical differentiation of the brain. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Variation of clinical target volume definition in three-dimensional conformal radiation therapy for prostate cancer

    International Nuclear Information System (INIS)

    Valicenti, Richard K.; Sweet, John W.; Hauck, Walter W.; Hudes, Richard S.; Lee, Tony; Dicker, Adam P.; Waterman, Frank M.; Anne, Pramila R.; Corn, Benjamin W.; Galvin, James M.

    1999-01-01

    Purpose: Currently, three-dimensional conformal radiation therapy (3D-CRT) planning relies on the interpretation of computed tomography (CT) axial images for defining the clinical target volume (CTV). This study investigates the variation among multiple observers to define the CTV used in 3D-CRT for prostate cancer. Methods and Materials: Seven observers independently delineated the CTVs (prostate ± seminal vesicles [SV]) from the CT simulation data of 10 prostate cancer patients undergoing 3D-CRT. Six patients underwent CT simulation without the use of contrast material and serve as a control group. The other 4 had urethral and bladder opacification with contrast medium. To determine interobserver variation, we evaluated the derived volume, the maximum dimensions, and the isocenter for each examination of CTV. We assessed the reliability in the CTVs among the observers by correlating the variation for each class of measurements. This was estimated by intraclass correlation coefficient (ICC), with 1.00 defining absolute correlation. Results: For the prostate volumes, the ICC was 0.80 (95% confidence interval [CI]: 0.56-0.96). This changed to 0.92 (95% CI: 0.75-0.99) with the use of contrast material. Similarly, the maximal prostatic dimensions were reliable and improved. There was poor agreement in defining the SV. For this structure, the ICC never exceeded 0.28. The reliability of the isocenter was excellent, with the ICC exceeding 0.83 and 0.90 for the prostate ± SV, respectively. Conclusions: In 3D-CRT for prostate cancer, there was excellent agreement among multiple observers to define the prostate target volume but poor agreement to define the SV. The use of urethral and bladder contrast improved the reliability of localizing the prostate. For all CTVs, the isocenter was very reliable and should be used to compare the variation in 3D dosimetry among multiple observers

  14. MANAJEMEN KULTUR ROTIFER DENGAN TANGKI VOLUME KECIL

    Directory of Open Access Journals (Sweden)

    Philip Teguh Imanto

    2009-04-01

    Full Text Available Keberhasilan pembenihan ikan sangat dipengaruhi keberhasilan produksi jasad pakan rotifer secara tepat dan efisien. Penelitian kultur rotifer dengan tangki volume kecil bertujuan untuk mendapatkan efisiensi produksi yang paling optimal dan memenuhi prinsip dasar akuakultur low volume high density. Penelitian menggunakan tangki polyethylene dengan volume 500 L dan volume media awal 100 L, padat tebar awal 200 ind. rotifer per mL dengan sediaan pakan dasar fitoplankton Nannocloropsis occulata, ragi roti (0,05 g/mio.rot./feeding dan suplemen Scott emulsion (0,005 g/mio.rot./feeding. Penelitian dilakukan secara bertahap; tahap pertama (I tanpa penambahan air laut, peningkatan volume hanya dari penambahan 15 L Nannochloropsis tiap hari sampai hari kelima, tahap kedua (II dengan penambahan alga 40 L dan air laut 40 L; serta tahap ketiga (III dengan menggandakan pemberian ragi roti. Hasil penelitian menunjukkan bahwa pada percobaan tahap I: total produksi rata-rata 122,37 x 106 ind. rotifer, pada tahap II: 97,67 x 106 ind. rotifer, dan pada tahap III: dicapai rata-rata total produksi tertinggi dengan 187,17 x 106 ind. rotifer per tanki kultur 500 L. Pengelolaan kultur pada tahap III memberikan hasil terbaik dengan simpangan terkecil antar tangki kultur ulangan, dan membuktikan sebagai pengelolaan terbaik untuk kultur rotifer dengan tangki volume kecil.  Success of marine seed production is highly influenced by effective and efficient production performance of life food rotifer. Observation on rotifer culture using small volume tank was aimed to get the optimum production and efficiency, to fulfill the basic principle of aquaculture “low volume high density”. Polyethylene tanks of 500 L. were used as culture container, with initial 100 liter sea water as culture medium and initial density of 200 ind. rotifer per mL. N. occulata, baker yeast (0.05 g/mio.rotifer/feeding and Scott emulsion (0.005 g/mio.rotifer/feeding were used as basic feed, and

  15. Radiographic determination of urinary bladder volume and residual urine volume

    International Nuclear Information System (INIS)

    Klumair, J.

    1977-01-01

    In the course of a long study the author has tested most of the methods for determination of urinary bladder volume. A radiographic method which can state bladder volume exactly in cc's is attainable only with great time and effort. In the author's experience, however, it is possible, by means of a pattern in connection with a IVP, to estimate residual urine volume from a post-void picture of the bladder with sufficient accuracy for practical purposes. An account is given of the production of this pattern and of two relatively simple calculations for residual volume based on AP and lateral views of circular- and ellipsoid-shaped bladders. Also discussed is the radiation exposure which varies with the radiographic methods used. In male patients, the radiation exposure appears to be negligible, especially when the testicles are protected by a radiation shield. In female patients - which make up only a small fraction of all patients -, radiation exposure is higher but must be accepted. (orig./MG) [de

  16. Rectal compliance as a routine measurement: extreme volumes have direct clinical impact and normal volumes exclude rectum as a problem.

    Science.gov (United States)

    Felt-Bersma, R J; Sloots, C E; Poen, A C; Cuesta, M A; Meuwissen, S G

    2000-12-01

    The clinical impact of rectal compliance and sensitivity measurement is not clear. The aim of this study was to measure the rectal compliance in different patient groups compared with controls and to establish the clinical effect of rectal compliance. Anorectal function tests were performed in 974 consecutive patients (284 men). Normal values were obtained from 24 controls. Rectal compliance measurement was performed by filling a latex rectal balloon with water at a rate of 60 ml per minute. Volume and intraballoon pressure were measured. Volume and pressure at three sensitivity thresholds were recorded for analysis: first sensation, urge, and maximal toleration. At maximal toleration, the rectal compliance (volume/pressure) was calculated. Proctoscopy, anal manometry, anal mucosal sensitivity, and anal endosonography were also performed as part of our anorectal function tests. No effect of age or gender was observed in either controls or patients. Patients with fecal incontinence had a higher volume at first sensation and a higher pressure at maximal toleration (P = 0.03), the presence of a sphincter defect or low or normal anal pressures made no difference. Patients with constipation had a larger volume at first sensation and urge (P 500 ml had complaints of constipation. No correlation between rectal and anal mucosal sensitivity was found. Rectal compliance measurement with a latex balloon is easily feasible. In this series of 974 patients, some patient groups showed an abnormal rectal visceral sensitivity and compliance, but there was an overlap with controls. Rectal compliance measurement gave a good clinical impression about the contribution of the rectum to the anorectal problem. Patients with proctitis and pouchitis had the smallest rectal compliance. A maximal toleration volume 500 ml was only seen in constipated patients, and therapy should be given to prevent further damage to the pelvic floor. Values close to or within the normal range rule out the

  17. Effects of plyometric training volume and training surface on explosive strength.

    Science.gov (United States)

    Ramírez-Campillo, Rodrigo; Andrade, David C; Izquierdo, Mikel

    2013-10-01

    The purpose of this study is to examine the effects of different volume and training surfaces during a short-term plyometric training program on neuromuscular performance. Twenty-nine subjects were randomly assigned to 4 groups: control group (CG, n = 5), moderate volume group (MVG, n = 9, 780 jumps), moderate volume hard surface group (MVGHS, n = 8, 780 jumps), and high volume group (HVG, n = 7, 1,560 jumps). A series of tests were performed by the subjects before and after 7 weeks of plyometric training. These tests were measurement of maximum strength (5 maximum repetitions [5RMs]), drop jumps (DJs) of varying heights (20, 40, and 60 cm), squat and countermovement jumps (SJ and CMJ, respectively), timed 20-m sprint, agility, body weight, and height. The results of the present study suggest that high training volume leads to a significant increase in explosive performance that requires fast stretch-shortening cycle (SSC) actions (such as DJ and sprint) in comparison to what is observed after a moderate training volume regimen. Second, when plyometric training is performed on a hard training surface (high-impact reaction force), a moderate training volume induces optimal stimulus to increase explosive performance requiring fast SSC actions (e.g., DJ), maximal dynamic strength enhancement, and higher training efficiency. Thus, a finding of interest in the study was that after 7 weeks of plyometric training, performance enhancement in maximal strength and in actions requiring fast SSC (such as DJ and sprint) were dependent on the volume of training and the surface on which it was performed. This must be taken into account when using plyometric training on different surfaces.

  18. Volume simplicity constraint in the Engle-Livine-Pereira-Rovelli spin foam model

    Science.gov (United States)

    Bahr, Benjamin; Belov, Vadim

    2018-04-01

    We propose a quantum version of the quadratic volume simplicity constraint for the Engle-Livine-Pereira-Rovelli spin foam model. It relies on a formula for the volume of 4-dimensional polyhedra, depending on its bivectors and the knotting class of its boundary graph. While this leads to no further condition for the 4-simplex, the constraint becomes nontrivial for more complicated boundary graphs. We show that, in the semiclassical limit of the hypercuboidal graph, the constraint turns into the geometricity condition observed recently by several authors.

  19. Radiocardiographic determination of the stroke volume and of the heart minute volume in athletes

    Energy Technology Data Exchange (ETDEWEB)

    Sattler, R; Stoll, W [Friedrich-Schiller-Universitaet, Jena (German Democratic Republic). Radiologische Klinik

    1981-11-01

    Radiocardiography, a novel radioisotope method for the problemless determination of many cardiodynamic parameters which can be applied also at given physical exercise is presented. On the basis of stroke volume and heart minute volume values from 35 athletes practising different sports and of a comparison with normal values reported in the literature, differences in the cardiac adaptation and the function of athletic hearts and so-called normal hearts are pointed out. The stroke volume of endurance-trained athletes exceeds that of untrained individuals by 30-40 ml. Under exercise the increase of the stroke volume is considerably greater in endurance athletes than in individuals practising other sports or in untrained subjects. At rest the values of the heart minute volume are almost the same in athletes and untrained individuals. Under exercise the heart minute volume of endurance athletes (40 l/min) is nearly twice that of untrained individuals (volume reserve of the athlete).

  20. Radiocardiographic determination of the stroke volume and of the heart minute volume in athletes

    International Nuclear Information System (INIS)

    Sattler, R.; Stoll, W.

    1981-01-01

    Radiocardiography, a novel radioisotope method for the problemless determination of many cardiodynamic parameters which can be applied also at given physical exercise is presented. On the basis of stroke volume and heart minute volume values from 35 athletes practising different sports and of a comparison with normal values reported in the literature, differences in the cardiac adaptation and the function of athletic hearts and so-called normal hearts are pointed out. The stroke volume of endurance-trained athetes exceed that of untrained individuals by 30-40 ml. Under exercise the increase of the stroke volume is considerably greater in endurance athletes than in individuals practising other sports or in untrained subjects. At rest the values of the heart minute volume are almost the same in athletes and untrained individuals. Under exercise the heart minute volume of endurance athletes (40 l/min) is nearly twice that of untrained individuals (volume reserve of the athlete). (author)

  1. Prediction of resource volumes at untested locations using simple local prediction models

    Science.gov (United States)

    Attanasi, E.D.; Coburn, T.C.; Freeman, P.A.

    2006-01-01

    This paper shows how local spatial nonparametric prediction models can be applied to estimate volumes of recoverable gas resources at individual undrilled sites, at multiple sites on a regional scale, and to compute confidence bounds for regional volumes based on the distribution of those estimates. An approach that combines cross-validation, the jackknife, and bootstrap procedures is used to accomplish this task. Simulation experiments show that cross-validation can be applied beneficially to select an appropriate prediction model. The cross-validation procedure worked well for a wide range of different states of nature and levels of information. Jackknife procedures are used to compute individual prediction estimation errors at undrilled locations. The jackknife replicates also are used with a bootstrap resampling procedure to compute confidence bounds for the total volume. The method was applied to data (partitioned into a training set and target set) from the Devonian Antrim Shale continuous-type gas play in the Michigan Basin in Otsego County, Michigan. The analysis showed that the model estimate of total recoverable volumes at prediction sites is within 4 percent of the total observed volume. The model predictions also provide frequency distributions of the cell volumes at the production unit scale. Such distributions are the basis for subsequent economic analyses. ?? Springer Science+Business Media, LLC 2007.

  2. Influence of volume on intraoperatively irradiated canine ureters

    International Nuclear Information System (INIS)

    Gillette, S.M.; Powers, B.E.; Thames, H.D.; Vujaskovic, Z.; LaRue, S.M.; Park, R.D.; Gillette, E.L.

    1995-01-01

    Purpose/Objective: Intraoperative radiation therapy (IORT) is used to deliver high single doses of radiation to the tumor bed following surgical removal of various abdominal malignancies. The advantage of IORT is the ability to remove sensitive normal tissues from the treatment field and limit the volume of normal tissue irradiated. The purpose of this study was to determine dose-volume relationships for retroperitoneal tissues. Materials and methods: 134 adult beagle dogs were irradiated to the surgically exposed paraaortic area. Normal tissues included in the treatment field were aorta, peripheral nerve, ureter, bone and the muscle. Groups of 4 - 8 dogs were irradiated to doses ranging from 18 - 54 Gy for a 2x5 cm field, from 12 - 46 Gy for a 4x5 cm field, and 12 - 42 Gy to an 8x5 cm field. The radiations were done using 6 MeV electrons from a linear accelerator. Dogs were observed for three years after radiation at which time they were euthanatized, perfused and tissues taken for histologic and histomorphometric evaluation. Transverse sections of the ureter were taken from the proximal, middle and distal segments. Histologically, proximal portions of the ureters with greater than 5 times normal diameter were considered to have severe hydroureter. Ureteral strictures and hydroneophrosis were evaluated by excretory urograms. Excretory urograms were done prior to treatment and annually after treatment or prior to necropsy for each dog in the experiments. A grading system was devised for predicting ureteral stenosis based on ureteral and renal pelvic dilatation. Results: A strong dose and volume relationship was identified for ureteral injury using the mixture model analysis which takes into account latency as well as dose. Subsequent to earlier edema, fibrin and vessel damage, progressive fibrosis developed and likely caused uteral stricture resulting in hydroureter. Severe hydroureter was observed as early as three months. The ED 50 for hydroureter determined

  3. The Increase of The Mean Platelet Volume in Patients With Intracerebral Haemorrhage

    Directory of Open Access Journals (Sweden)

    Adalet Arıkanoğlu

    2012-06-01

    Full Text Available OBJECTIVE: The mean platelet volume (MPV is a biomarker of platelet function and activity. The influence of platelet function disorders on the aetiology of intracerebral haemorrhages (ICH and mortality is not clear yet. The purpose of this study is to investigate the change in the MPV values in patients with ICH and to observe its influence on mortality in a retrospective manner. METHODS: Sixty-six patients with intracerebral haemorrhage (32 males, 34 females; mean age: 61.9± 16.9 were enrolled in the study. Patients with ICH were divided into two groups as those who died within the first 10 days and those who survived. The MPV values and the haematoma volumes were compared between the groups. Also, the MPV values and platelet counts of the patients with ICH were compared with the values of healthy volunteers from similar age and sex groups (27 males, 17 females; mean age: 59.9 ±3.2. RESULTS: The MPV values of the patients with ICH measured within 24 hours following the intracerebral haemorrhage (8.33 ± 1.27 fl/mL were statistically significantly higher than the MPV values of the control group (7.76 ± 1.14 fl/mL (p=0.018. The platelet counts of the patients with ICH also measured within the first 24 hours (235.8±94.9 x103/mL were statistically significantly lower than the platelet counts of the control group (279.1 ± 94.9 x103/mL (p=0.022. No statistically significant difference in terms of the MPV values and platelet counts was observed between the patients with ICH who died within the first 10 days and those who survived (p>0.05. However, the difference observed in the haematoma volume between the patients with ICH who died within the first 10 days (31.1 ±33.7 ml and those who survived (8.7± 13.4 ml was statistically significant (p<0.001. No correlation was found between the haematoma volume and the MPV value in the patients with ICH. CONCLUSION: The increase observed in the mean platelet volume in patients with ICH may point to a

  4. Implications of changing scattering properties on Greenland ice sheet volume change from Cryosat-2 altimetry

    DEFF Research Database (Denmark)

    Simonsen, Sebastian Bjerregaard; Sørensen, Louise Sandberg

    2017-01-01

    ) in the elevation change algorithm, to correct for temporal changes in the ratio between surface- and volume-scatter in Cryosat-2 observations. We present elevation and volume changes for the Greenland ice sheet in the period from 2010 until 2014. The waveform parameters considered here are the backscatter...... waveform parameters to be applicable for correcting for changes in volume scattering. The best results in the Synthetic Aperture Radar Interferometric mode area of the GrIS are found when applying only the backscatter correction, whereas the best result in the Low Resolution Mode area is obtained by only......Long-term observations of surface elevation change of the Greenland ice sheet (GrIS) is of utmost importance when assessing the state of the ice sheet. Satellite radar altimetry offers a long time series of data over the GrIS, starting with ERS-1 in 1991. ESA's Cryosat-2 mission, launched in 2010...

  5. Growth Patterns of Fetal Lung Volumes in Healthy Fetuses and Fetuses With Isolated Left-Sided Congenital Diaphragmatic Hernia.

    Science.gov (United States)

    Ruano, Rodrigo; Britto, Ingrid Schwach Werneck; Sananes, Nicolas; Lee, Wesley; Sangi-Haghpeykar, Haleh; Deter, Russell L

    2016-06-01

    To evaluate fetal lung growth using 3-dimensional sonography in healthy fetuses and those with congenital diaphragmatic hernia (CDH). Right and total lung volumes were serially evaluated by 3-dimensional sonography in 66 healthy fetuses and 52 fetuses with left-sided CDH between 20 and 37 weeks' menstrual age. Functions fitted to these parameters were compared for 2 groups: (1) healthy versus those with CDH; and (2) fetuses with CHD who survived versus those who died. Fetal right and total lung volumes as well as fetal observed-to-expected right and total lung volume ratios were significantly lower in fetuses with CDH than healthy fetuses (Pvolume ratios did not vary with menstrual age in healthy fetuses or in those with CDH (independent of outcome). Lung volume rates were lower in fetuses with left-sided CDH compared to healthy fetuses, as well as in fetuses with CDH who died compared to those who survived. The observed-to-expected right and total lung volume ratios were relatively constant throughout menstrual age in fetuses with left-sided CDH, suggesting that the origin of their lung growth abnormalities occurred before 20 weeks and did not progress. The observed-to-expected ratios may be useful in predicting the outcome in fetuses with CDH independent of menstrual age. © 2016 by the American Institute of Ultrasound in Medicine.

  6. Evaluation of dose-volume histograms after prostate seed implantation. 4-year experience

    International Nuclear Information System (INIS)

    Hoinkis, C.; Lehmann, D.; Winkler, C.; Herrmann, T.; Hakenberg, O.W.; Wirth, M.P.

    2004-01-01

    in the D90 post can be observed and results in a stable technique after 18 patients. An important factor influencing the learning curve in addition to the precision of seed positioning is organ volume definition on postimplant imaging. (orig.)

  7. Tumor Volume Changes Assessed by Three-Dimensional Magnetic Resonance Volumetry in Rectal Cancer Patients After Preoperative Chemoradiation: The Impact of the Volume Reduction Ratio on the Prediction of Pathologic Complete Response

    International Nuclear Information System (INIS)

    Kang, Jeong Hyun; Kim, Young Chul; Kim, Hyunki; Kim, Young Wan; Hur, Hyuk; Kim, Jin Soo; Min, Byung Soh; Kim, Hogeun; Lim, Joon Seok; Seong, Jinsil; Keum, Ki Chang; Kim, Nam Kyu

    2010-01-01

    Purpose: The aim of this study was to determine the correlation between tumor volume changes assessed by three-dimensional (3D) magnetic resonance (MR) volumetry and the histopathologic tumor response in rectal cancer patients undergoing preoperative chemoradiation therapy (CRT). Methods and Materials: A total of 84 patients who underwent preoperative CRT followed by radical surgery were prospectively enrolled in the study. The post-treatment tumor volume and tumor volume reduction ratio (% decrease ratio), as shown by 3D MR volumetry, were compared with the histopathologic response, as shown by T and N downstaging and the tumor regression grade (TRG). Results: There were no significant differences in the post-treatment tumor volume and the volume reduction ratio shown by 3D MR volumetry with respect to T and N downstaging and the tumor regression grade. In a multivariate analysis, the tumor volume reduction ratio was not significantly associated with T and N downstaging. The volume reduction ratio (>75%, p = 0.01) and the pretreatment carcinoembryonic antigen level (≤3 ng/ml, p = 0.01), but not the post-treatment volume shown by 3D MR (≤ 5ml), were, however, significantly associated with an increased pathologic complete response rate. Conclusion: More than 75% of the tumor volume reduction ratios were significantly associated with a high pathologic complete response rate. Therefore, limited treatment options such as local excision or simple observation might be considered after preoperative CRT in this patient population.

  8. Cerebral gray matter volume in patients with chronic migraine: correlations with clinical features.

    Science.gov (United States)

    Coppola, Gianluca; Petolicchio, Barbara; Di Renzo, Antonio; Tinelli, Emanuele; Di Lorenzo, Cherubino; Parisi, Vincenzo; Serrao, Mariano; Calistri, Valentina; Tardioli, Stefano; Cartocci, Gaia; Ambrosini, Anna; Caramia, Francesca; Di Piero, Vittorio; Pierelli, Francesco

    2017-12-08

    To date, few MRI studies have been performed in patients affected by chronic migraine (CM), especially in those without medication overuse. Here, we performed magnetic resonance imaging (MRI) voxel-based morphometry (VBM) analyses to investigate the gray matter (GM) volume of the whole brain in patients affected by CM. Our aim was to investigate whether fluctuations in the GM volumes were related to the clinical features of CM. Twenty untreated patients with CM without a past medical history of medication overuse underwent 3-Tesla MRI scans and were compared to a group of 20 healthy controls (HCs). We used SPM12 and the CAT12 toolbox to process the MRI data and to perform VBM analyses of the structural T1-weighted MRI scans. The GM volume of patients was compared to that of HCs with various corrected and uncorrected thresholds. To check for possible correlations, patients' clinical features and GM maps were regressed. Initially, we did not find significant differences in the GM volume between patients with CM and HCs (p tablets taken per month. No gross morphometric changes were observed in patients with CM when compared with HCs. However, using more-liberal uncorrected statistical thresholds, we observed that CM is associated with subtle GM volume changes in several brain areas known to be involved in nociception/antinociception, multisensory integration, and analgesic dependence. We speculate that these slight morphometric impairments could lead, at least in a subgroup of patients, to the development and continuation of maladaptive acute medication usage.

  9. Daily Prostate Volume and Position Monitoring Using Implanted Gold Markers and On-Board Imaging during Radiotherapy

    Directory of Open Access Journals (Sweden)

    Linda Kašaová

    2011-01-01

    Full Text Available Purpose: This study aimed to evaluate prostate volume changes and prostate motions during radiotherapy. Methods: In 2010, twenty-five patients were treated for prostate cancer by external beam radiotherapy with implanted fiducial markers. Coordinates of three gold markers on kilovoltage images were calculated daily. Volume changes in target structure were observed through changes in intermarker distances. Differences in patient position between laser-tattoo alignment and gold marker localization were evaluated. Intrafraction motion was assessed by measuring marker displacement on kilovoltage images acquired before and after fraction delivery. Results: Prostate shrinkage was observed in 60% of patients. The average shrinkage was 7% of the prostate’s initial volume. Corrections after laser-tattoo alignment remained mostly below 1 cm. The difference between marker centroid position on the actual images and the planning images was 2 ± 1 mm on average. The extension of intrafraction movements was 7.6 ± 0.2 mm on average. Conclusions: In our retrospective study, the possibility for prostate volume changes during radiotherapy was revealed. Intrafraction movements turned out to be the limiting factor in safety margin reduction.

  10. Ada (Trade Name) Bibliography. Volume 1.

    Science.gov (United States)

    1983-05-01

    GLENN DOCUMENT NUMBER: 3268 TYPE: JOURNAL ARTICLE .5-., SCIENCE VOL 215 ISSUE 34 PP. 775-779S In this article, two principal themes are observed in...AINST LANAN RD NAY 83 ND9S-8-C-936 UNCLASSIFIED F/6 12/5 ML -4.4 ’-4-4----" ’°p..l i . d N N L. 131 t ’ll /II~ Ada Bibliography Volume I 95 𔃾- This...BUDAPEST,HUNGARY 4102 -01 ON THE TYPE CONCEPT OF ADA 6224 -03 UNORTHOGONALITIES IN THE IDENTIFICATION RULES IN ADA BACON, GLENN , IBM SANTA TERESA LABS

  11. Change in brain and lesion volumes after CEE therapies: the WHIMS-MRI studies.

    Science.gov (United States)

    Coker, Laura H; Espeland, Mark A; Hogan, Patricia E; Resnick, Susan M; Bryan, R Nick; Robinson, Jennifer G; Goveas, Joseph S; Davatzikos, Christos; Kuller, Lewis H; Williamson, Jeff D; Bushnell, Cheryl D; Shumaker, Sally A

    2014-02-04

    To determine whether smaller brain volumes in older women who had completed Women's Health Initiative (WHI)-assigned conjugated equine estrogen-based hormone therapy (HT), reported by WHI Memory Study (WHIMS)-MRI, correspond to a continuing increased rate of atrophy an average of 6.1 to 7.7 years later in WHIMS-MRI2. A total of 1,230 WHI participants were contacted: 797 (64.8%) consented, and 729 (59%) were rescanned an average of 4.7 years after the initial MRI scan. Mean annual rates of change in total brain volume, the primary outcome, and rates of change in ischemic lesion volumes, the secondary outcome, were compared between treatment groups using mixed-effect models with adjustment for trial, clinical site, age, intracranial volumes, and time between MRI measures. Total brain volume decreased an average of 3.22 cm(3)/y in the active arm and 3.07 cm(3)/y in the placebo arm (p = 0.53). Total ischemic lesion volumes increased in both arms at a rate of 0.12 cm(3)/y (p = 0.88). Conjugated equine estrogen-based postmenopausal HT, previously assigned at WHI baseline, did not affect rates of decline in brain volumes or increases in brain lesion volumes during the 4.7 years between the initial and follow-up WHIMS-MRI studies. Smaller frontal lobe volumes were observed as persistent group differences among women assigned to active HT compared with placebo. Women with a history of cardiovascular disease treated with active HT, compared with placebo, had higher rates of accumulation in white matter lesion volume and total brain lesion volume. Further study may elucidate mechanisms that explain these findings.

  12. Effect of malaria on placental volume measured using three-dimensional ultrasound: a pilot study

    Directory of Open Access Journals (Sweden)

    Rijken Marcus J

    2012-01-01

    Full Text Available Abstract Background The presence of malaria parasites and histopathological changes in the placenta are associated with a reduction in birth weight, principally due to intrauterine growth restriction. The aim of this study was to examine the feasibility of studying early pregnancy placental volumes using three-dimensional (3D ultrasound in a malaria endemic area, as a small volume in the second trimester may be an indicator of intra-uterine growth restriction and placental insufficiency. Methods Placenta volumes were acquired using a portable ultrasound machine and a 3D ultrasound transducer and estimated using the Virtual Organ Computer-aided AnaLysis (VOCAL image analysis software package. Intra-observer reliability and limits of agreement of the placenta volume measurements were calculated. Polynomial regression models for the mean and standard deviation as a function of gestational age for the placental volumes of uninfected women were created and tested. Based on these equations each measurement was converted into a z -score. The z-scores of the placental volumes of malaria infected and uninfected women were then compared. Results Eighty-four women (uninfected = 65; infected = 19 with a posterior placenta delivered congenitally normal, live born, single babies. The mean placental volumes in the uninfected women were modeled to fit 5th, 10th, 50th, 90th and 95th centiles for 14-24 weeks' gestation. Most placenta volumes in the infected women were below the 50th centile for gestational age; most of those with Plasmodium falciparum were below the 10th centile. The 95% intra-observer limits of agreement for first and second measurements were ± 37.0 mL and ± 25.4 mL at 30 degrees and 15 degrees rotation respectively. Conclusion The new technique of 3D ultrasound volumetry of the placenta may be useful to improve our understanding of the pathophysiological constraints on foetal growth caused by malaria infection in early pregnancy.

  13. SU-F-T-40: Can CBCT Images Be Used for Volume Studies of Prostate Seed Implants for Boost Treatment?

    Energy Technology Data Exchange (ETDEWEB)

    Xu, H; Lee, S; Diwanji, T; Amin, P; Krudys, K; Guerrero, M [University of Maryland School of Medicine, Baltimore, MD (United States)

    2016-06-15

    Purpose: In our clinic, the planning CT is used for definitive and boost low-dose-rate (LDR) brachytherapy treatments to determine the ultrasound volume in the operating room (OR) at the time of the implant. While the CT overestimation of OR volume is known, a larger estimation discrepancy has been observed for boost treatments. A possible reason is the prostate size reduction during EBRT for boost patients. Since cone-beam CT (CBCT) is often used as routine imaging guidance of EBRT, this prostate volume change may be captured. This study investigates if CBCT taken during EBRT includes the volume change information and therefore beats CT in estimating the prostate OR volumes. Methods: 9 prostate patients treated with EBRT (45Gy in 1.8Gy per fractions to the whole pelvis) and I-125 seed implants (108Gy) were involved in this study. During EBRT, CBCT image guidance was performed on a weekly basis. For each patient, the prostate volumes on the first and the last available CBCT images were manually contoured by a physician. These volumes were then compared to each other and with the contoured volumes from the planning CT and from the ultrasound images in the OR. Results: The first and the last CBCT images did not show significant prostate volume change. Their average +/− standard deviation of prostate volumes were 24.4cc+/−14.6cc and 29.9cc+/−16.1cc, respectively (T-test p=0.68). The ratio of the OR volume to the last CBCT (0.71+/−0.21) was not significantly different from the ratio of OR volumes to the planning CT (0.61+/−0.13) (p=0.25). Conclusion: In this study, CBCT does not show significant prostate volume changes during EBRT. CBCT and CT volumes are quite consistent and no improvement of volume estimation using CBCT is observed. The advantage of CBCT as a replacement of CT for volume study of boost LDR brachytherapy is limited.

  14. Tolstoy, Vygotsky, and the Making of Meaning.

    Science.gov (United States)

    Berthoff, Ann E.

    1978-01-01

    Leo Tolstoy and Lev Vygotsky, like Sylvia Ashton-Warner, Maria Montessori, and Paulo Freire, base their educational philosophies on the heuristic power of language, the form-finding, and form-creating powers of the human mind. (DD)

  15. A glimpse beneath Antarctic sea ice: observation of platelet-layer thickness and ice-volume fraction with multi-frequency EM

    Science.gov (United States)

    Hendricks, S.; Hoppmann, M.; Hunkeler, P. A.; Kalscheuer, T.; Gerdes, R.

    2015-12-01

    In Antarctica, ice crystals (platelets) form and grow in supercooled waters below ice shelves. These platelets rise and accumulate beneath nearby sea ice to form a several meter thick sub-ice platelet layer. This special ice type is a unique habitat, influences sea-ice mass and energy balance, and its volume can be interpreted as an indicator for ice - ocean interactions. Although progress has been made in determining and understanding its spatio-temporal variability based on point measurements, an investigation of this phenomenon on a larger scale remains a challenge due to logistical constraints and a lack of suitable methodology. In the present study, we applied a lateral constrained Marquardt-Levenberg inversion to a unique multi-frequency electromagnetic (EM) induction sounding dataset obtained on the ice-shelf influenced fast-ice regime of Atka Bay, eastern Weddell Sea. We adapted the inversion algorithm to incorporate a sensor specific signal bias, and confirmed the reliability of the algorithm by performing a sensitivity study using synthetic data. We inverted the field data for sea-ice and sub-ice platelet-layer thickness and electrical conductivity, and calculated ice-volume fractions from platelet-layer conductivities using Archie's Law. The thickness results agreed well with drill-hole validation datasets within the uncertainty range, and the ice-volume fraction also yielded plausible results. Our findings imply that multi-frequency EM induction sounding is a suitable approach to efficiently map sea-ice and platelet-layer properties. However, we emphasize that the successful application of this technique requires a break with traditional EM sensor calibration strategies due to the need of absolute calibration with respect to a physical forward model.

  16. Substantial interobserver variation of thyroid volume and function by visual evaluation of thyroid (99m)Tc scintigraphy

    DEFF Research Database (Denmark)

    Soelberg, Kerstin; Grupe, Peter; Boel-Jørgensen, Henrik

    2014-01-01

    (99m)Tc-pertechnetate scintigraphy is much used in the evaluation of patients with nodular goitre. We investigated the ability of experienced observers to estimate the thyroid 24-h (131)I uptake (RAIU) and the thyroid volume by visual evaluation of the scintigram.......(99m)Tc-pertechnetate scintigraphy is much used in the evaluation of patients with nodular goitre. We investigated the ability of experienced observers to estimate the thyroid 24-h (131)I uptake (RAIU) and the thyroid volume by visual evaluation of the scintigram....

  17. Mean nuclear volume

    DEFF Research Database (Denmark)

    Mogensen, O.; Sørensen, Flemming Brandt; Bichel, P.

    1999-01-01

    We evaluated the following nine parameters with respect to their prognostic value in females with endometrial cancer: four stereologic parameters [mean nuclear volume (MNV), nuclear volume fraction, nuclear index and mitotic index], the immunohistochemical expression of cancer antigen (CA125...

  18. Research Studies Index. Authors and Subjects. Volume 1 through Volume 43 (1929-1975).

    Science.gov (United States)

    Drazan, Joseph, Comp.; Scott, Paula, Comp.

    This volume contains author and subject indexes for volumes 1 through 43 (1929-1975) of "Research Studies," a scholarly, multi-disciplinary quarterly published at Washington State University. Each author index entry includes the title, volume, and inclusive pagination of the article. The subject index is a keyword-out-of-context…

  19. Introduction to geometric nonlinear control; Linearization, observability, decoupling

    Energy Technology Data Exchange (ETDEWEB)

    Respondek, W [Laboratoire de Mathematiques, INSA de Rouen (France)

    2002-07-15

    These notes are devoted to the problems of linearization, observability, and decoupling of nonlinear control systems. Together with notes of Bronislaw Jakubczyk in the same volume, they form an introduction to geometric methods in nonlinear control theory. In the first part we discuss equivalence of control systems. We consider various aspects of the problem: state-space and feedback equivalence, local and global equivalence, equivalence to linear and partially linear systems. In the second part we present the notion of observability and give a geometric rank condition for local observability and an algebraic characterization of local observability. We discuss unm observability, decompositions of non-observable systems, and properties of generic observable systems. In the third part we introduce the notion of invariant distributions and discuss disturbance decoupling and input-output decoupling. Many concepts and results are illustrated with examples. (author)

  20. Effect of volume expansion on systemic hemodynamics and central and arterial blood volume in cirrhosis

    DEFF Research Database (Denmark)

    Møller, S; Bendtsen, F; Henriksen, Jens Henrik Sahl

    1995-01-01

    , and arterial pressure were determined before and during a volume expansion induced by infusion of a hyperosmotic galactose solution. RESULTS: During volume expansion, the central and arterial blood volume increased significantly in patients with class A and controls, whereas no significant change was found...... in patients with either class B or class C. Conversely, the noncentral blood volume increased in patients with class B and C. In both patients and controls, the cardiac output increased and the systemic vascular resistance decreased, whereas the mean arterial blood pressure did not change significantly......BACKGROUND & AIMS: Systemic vasodilatation in cirrhosis may lead to hemodynamic alterations with reduced effective blood volume and decreased arterial blood pressure. This study investigates the response of acute volume expansion on hemodynamics and regional blood volumes in patients with cirrhosis...

  1. Quantifying Standing Dead Tree Volume and Structural Loss with Voxelized Terrestrial Lidar Data

    Science.gov (United States)

    Popescu, S. C.; Putman, E.

    2017-12-01

    Standing dead trees (SDTs) are an important forest component and impact a variety of ecosystem processes, yet the carbon pool dynamics of SDTs are poorly constrained in terrestrial carbon cycling models. The ability to model wood decay and carbon cycling in relation to detectable changes in tree structure and volume over time would greatly improve such models. The overall objective of this study was to provide automated aboveground volume estimates of SDTs and automated procedures to detect, quantify, and characterize structural losses over time with terrestrial lidar data. The specific objectives of this study were: 1) develop an automated SDT volume estimation algorithm providing accurate volume estimates for trees scanned in dense forests; 2) develop an automated change detection methodology to accurately detect and quantify SDT structural loss between subsequent terrestrial lidar observations; and 3) characterize the structural loss rates of pine and oak SDTs in southeastern Texas. A voxel-based volume estimation algorithm, "TreeVolX", was developed and incorporates several methods designed to robustly process point clouds of varying quality levels. The algorithm operates on horizontal voxel slices by segmenting the slice into distinct branch or stem sections then applying an adaptive contour interpolation and interior filling process to create solid reconstructed tree models (RTMs). TreeVolX estimated large and small branch volume with an RMSE of 7.3% and 13.8%, respectively. A voxel-based change detection methodology was developed to accurately detect and quantify structural losses and incorporated several methods to mitigate the challenges presented by shifting tree and branch positions as SDT decay progresses. The volume and structural loss of 29 SDTs, composed of Pinus taeda and Quercus stellata, were successfully estimated using multitemporal terrestrial lidar observations over elapsed times ranging from 71 - 753 days. Pine and oak structural loss rates

  2. Comparison of Tidal Volumes at the Endotracheal Tube and at the Ventilator.

    Science.gov (United States)

    Kim, Paul; Salazar, Adler; Ross, Patrick A; Newth, Christopher J L; Khemani, Robinder G

    2015-11-01

    Lung protective ventilation for children with acute respiratory distress syndrome requires accurate assessment of tidal volume. Although modern ventilators compensate for ventilator tubing compliance, tidal volume measured at the ventilator may not be accurate, particularly in small children. Although ventilator-specific proximal flow sensors that measure tidal volume at the endotracheal tube have been developed, there is little information regarding their accuracy. We sought to test the accuracy of ventilator measured tidal volume with and without proximal flow sensors against a calibrated pneumotachometer in children. Prospective, observational. Tertiary care PICU. Fifty-one endotracheally intubated and mechanically ventilated children younger than 18 years. Tidal volumes were measured at the ventilator, using a ventilator-specific flow sensor, and a calibrated pneumotachometer connected to the SensorMedics 2600A Pediatric Pulmonary Function Cart. In a pressure control mode of ventilation: median tidal volume measured with the pneumotachometer (9.5 mL/kg [interquartile range, 8.2-11.7 mL/kg]) was significantly higher than tidal volume measured either at the ventilator (8.2 mL/kg [7.1-9.6 mL/kg]) or at the proximal flow sensor (8.1 mL/kg [7.2-10.0 mL/kg]) (p tidal volume measured with the pneumotachometer (10.2 mL/kg [8.8-12.4 mL/kg]) was significantly higher than tidal volume measured either at the ventilator (8.0 mL/kg [7.1-9.7 mL/kg]) or at the proximal flow sensor (8.5 mL/kg [7.3-10.4 mL/kg]) (p Tidal volume measured either at the endotracheal tube with a proximal flow sensor or at the ventilator with compensation for tubing compliance are both significantly lower than tidal volume measured with a calibrated pneumotachometer. This underestimation of delivered tidal volume may be particularly important when managing children with acute respiratory distress syndrome.

  3. Aperiodic Volume Optics

    Science.gov (United States)

    Gerke, Tim D.

    Presented in this thesis is an investigation into aperiodic volume optical devices. The three main topics of research and discussion are the aperiodic volume optical devices that we call computer-generated volume holograms (CGVH), defects within periodic 3D photonic crystals, and non-periodic, but ordered 3D quasicrystals. The first of these devices, CGVHs, are designed and investigated numerically and experimentally. We study the performance of multi-layered amplitude computer-generated volume holograms in terms of efficiency and angular/frequency selectivity. Simulation results show that such aperiodic devices can increase diffraction efficiency relative to periodic amplitude volume holograms while maintaining angular and wavelength selectivity. CGVHs are also designed as voxelated volumes using a new projection optimization algorithm. They are investigated using a volumetric diffraction simulation and a standard 3D beam propagation technique as well as experimentally. Both simulation and experiment verify that the structures function according to their design. These represent the first diffractive structures that have the capacity for generating arbitrary transmission and reflection wave fronts and that provide the ability for multiplexing arbitrary functionality given different illumination conditions. Also investigated and discussed in this thesis are 3D photonic crystals and quasicrystals. We demonstrate that these devices can be fabricated using a femtosecond laser direct writing system that is particularly appropriate for fabrication of such arbitrary 3D structures. We also show that these devices can provide 3D partial bandgaps which could become complete bandgaps if fabricated using high index materials or by coating lower index materials with high index metals. Our fabrication method is particularly suited to the fabrication of engineered defects within the periodic or quasi-periodic systems. We demonstrate the potential for fabricating defects within

  4. Fundamentals of the Physics of Solids Volume 2: Electronic Properties

    CERN Document Server

    Sólyom, Jenő

    2009-01-01

    This book is the second of a single-authored, three-volume series that aims to deliver a comprehensive and self-contained account of the vast field of solid-state physics. It goes far beyond most classic texts in the presentation of the properties of solids and experimentally observed phenomena, along with the basic concepts and theoretical methods used to understand them and the essential features of various experimental techniques. The first volume deals with the atomic and magnetic structure and dynamics of solids, the second with those electronic properties that can be understood in the one-particle approximation, and the third with the effects due to interactions and correlations between electrons. This volume is devoted to the electronic properties of metals and semiconductors in the independent-electron approximation. After a brief discussion of the free-electron models by Drude and Sommerfeld, the methods for calculating and measuring the band structure of Bloch electrons moving in the periodic potent...

  5. Effect of spray volume on the deposition, viability and infectivity of entomopathogenic nematodes in a foliar spray on vegetables.

    Science.gov (United States)

    Brusselman, Eva; Beck, Bert; Pollet, Sabien; Temmerman, Femke; Spanoghe, Pieter; Moens, Maurice; Nuyttens, David

    2012-10-01

    Spray volume can influence the amount of free water on the leaf surface and subsequently the ability of entomopathogenic nematodes (EPNs) to move. In this study, an investigation was made of the effect of spray volume (548, 730 and 1095 L ha(-1) ) on the deposition, viability and infectivity of EPNs against Galleria mellonella on savoy cabbage, cauliflower and leek. Increasing spray volume decreased nematode deposition on 7.1 cm2 leek leaf discs at a 15° angle with the spray nozzle. Although the number of living nematodes observed on leek after 240 min of exposure was not significantly different between the low-volume application (548 L ha(-1) ) and the high-volume application (1095 L ha(-1) ), a greater infectivity was obtained in the latter application. The higher number of droplets deposited on the leek discs in the high-volume application may have stimulated nematode movement. No significant effect of spray volume was observed on the relative deposition of Steinernema carpocapsae on the bottom side of cauliflower and savoy cabbage leaf discs. In spite of the low S. carpocapsae deposition on the bottom side of the savoy cabbage discs, high infectivity was obtained against G. mellonella. Using the lowest spray volume on savoy cabbage, infectivity decreased with increasing exposure time, while infectivity was not affected by exposure time when a spray volume of 730 L ha(-1) or more was used. Spray volume is an important application parameter, as it affects nematode infectivity. Future research should investigate the effect of spray volume in the field and its influence on the effect of adjuvants. Copyright © 2012 Society of Chemical Industry.

  6. Impact of the accuracy of automatic tumour functional volume delineation on radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Le Maitre, Amandine; Hatt, Mathieu; Pradier, Olivier; Cheze-le Rest, Catherine; Visvikis, Dimitris

    2012-01-01

    Over the past few years several automatic and semi-automatic PET segmentation methods for target volume definition in radiotherapy have been proposed. The objective of this study is to compare different methods in terms of dosimetry. For such a comparison, a gold standard is needed. For this purpose, realistic GATE-simulated PET images were used. Three lung cases and three H and N cases were designed with various shapes, contrasts and heterogeneities. Four different segmentation approaches were compared: fixed and adaptive thresholds, a fuzzy C-mean and the fuzzy locally adaptive Bayesian method. For each of these target volumes, an IMRT treatment plan was defined. The different algorithms and resulting plans were compared in terms of segmentation errors and ground-truth volume coverage using different metrics (V 95 , D 95 , homogeneity index and conformity index). The major differences between the threshold-based methods and automatic methods occurred in the most heterogeneous cases. Within the two groups, the major differences occurred for low contrast cases. For homogeneous cases, equivalent ground-truth volume coverage was observed for all methods but for more heterogeneous cases, significantly lower coverage was observed for threshold-based methods. Our study demonstrates that significant dosimetry errors can be avoided by using more advanced image-segmentation methods. (paper)

  7. Implantable bladder volume sensor based on resistor ladder network composed of conductive hydrogel composite.

    Science.gov (United States)

    Mi Kyung Kim; Hyojung Kim; Jung, Yeon Su; Adem, Kenana M A; Bawazir, Sarah S; Stefanini, Cesare; Lee, Hyunjoo J

    2017-07-01

    An accurate bladder volume monitoring system is a critical component in diagnosis and treatment of urological disorders. Here, we report an implantable bladder volume sensor with a multi-level resistor ladder which estimates the bladder volume through discrete resistance values. Discretization allows the sensor output to be resilient to the long-term drift, hysteresis, and degradation of the sensor materials. Our sensor is composed of biocompatible polypyrrole/agarose hydrogel composite. Because Young's modulus of this composite is comparable to that of the bladder wall, the effect of mechanical loading of the sensor on the bladder movement is minimized which allows more accurate volume monitoring. We also demonstrate the patterning and molding capability of this material by fabrication various structures. Lastly, we successfully demonstrate the functionality of the multi-level resistor ladder sensor as a bladder volume sensor by attaching the sensor on the pig's bladder and observing the impedance change of the sensor.

  8. Radiotherapy for non-small cell lung cancer: volume definition and patient selection. Annecy 1998 international Association for the study of lung cancer (IASLC) Workshop recommendations

    International Nuclear Information System (INIS)

    Mornex, F.; Loubeyre, P.; Van houtte, P.; Scalliet, P.

    1998-01-01

    Chemo-radiation is the standard treatment of unresectable, locally advanced non-small cell lung cancer, with a mean dose of 60-66 Gy, excluding escalation dose schemes. The standard treated volume includes primary tumor, ipsilateral hilar and mediastinal nodes, supraclavicular and contralateral nodes as well, regardless of the node status. This work tries to answer the question of the optimal volume to be treated. Drainage routes analysis is in favor of large volumes, while toxicity analysis favors small volumes. Combined modality treatment may increase the observed toxicity. The optimal volume definition is difficult, and requires available conformal therapy tools. Patients selection is another important issue. A volume definition is then attempted, based on the IASLC (International Association for the Study of Lung Cancer) Annecy workshop experience, highlighting the inter-observers discrepancies, and suggests basic recommendations to harmonize volume definition. (author)

  9. Effects of using nursing home residents to serve as group activity leaders: lessons learned from the RAP project.

    Science.gov (United States)

    Skrajner, Michael J; Haberman, Jessica L; Camp, Cameron J; Tusick, Melanie; Frentiu, Cristina; Gorzelle, Gregg

    2014-03-01

    Previous research has demonstrated that persons with early to moderate stage dementia are capable of leading small group activities for persons with more advanced dementia. In this study, we built upon this previous work by training residents in long-term care facilities to fill the role of group activity leaders using a Resident-Assisted Programming (RAP) training regimen. There were two stages to the program. In the first stage, RAP training was provided by researchers. In the second stage, RAP training was provided to residents by activities staff members of long-term care facilities who had been trained by researchers. We examine the effects of RAP implemented by researchers and by activities staff member on long-term care resident with dementia who took part in these RAP activities. We also examined effects produced by two types of small group activities: two Montessori-based activities and an activity which focuses on persons with more advanced dementia, based on the work of Jitka Zgola. Results demonstrate that levels of positive engagement seen in players during RAP (resident-led activities) were typically higher than those observed during standard activities programming led by site staff. In general, Montessori-Based Dementia Programming® produced more constructive engagement than Zgola-based programming (ZBP), though ZBP did increase a positive form of engagement involving observing activities with interest. In addition, RAP implemented by activities staff members produced effects that were, on the whole, similar to those produced when RAP was implemented by researchers. Implications of these findings for providing meaningful social roles for persons with dementia residing in long-term care, and suggestions for further research in this area, are discussed.

  10. Understanding the heterogeneity in volume overload and fluid distribution in decompensated heart failure is key to optimal volume management: role for blood volume quantitation.

    Science.gov (United States)

    Miller, Wayne L; Mullan, Brian P

    2014-06-01

    This study sought to quantitate total blood volume (TBV) in patients hospitalized for decompensated chronic heart failure (DCHF) and to determine the extent of volume overload, and the magnitude and distribution of blood volume and body water changes following diuretic therapy. The accurate assessment and management of volume overload in patients with DCHF remains problematic. TBV was measured by a radiolabeled-albumin dilution technique with intravascular volume, pre-to-post-diuretic therapy, evaluated at hospital admission and at discharge. Change in body weight in relation to quantitated TBV was used to determine interstitial volume contribution to total fluid loss. Twenty-six patients were prospectively evaluated. Two patients had normal TBV at admission. Twenty-four patients were hypervolemic with TBV (7.4 ± 1.6 liters) increased by +39 ± 22% (range, +9.5% to +107%) above the expected normal volume. With diuresis, TBV decreased marginally (+30 ± 16%). Body weight declined by 6.9 ± 5.2 kg, and fluid intake/fluid output was a net negative 8.4 ± 5.2 liters. Interstitial compartment fluid loss was calculated at 6.2 ± 4.0 liters, accounting for 85 ± 15% of the total fluid reduction. TBV analysis demonstrated a wide range in the extent of intravascular overload. Dismissal measurements revealed marginally reduced intravascular volume post-diuretic therapy despite large reductions in body weight. Mobilization of interstitial fluid to the intravascular compartment with diuresis accounted for this disparity. Intravascular volume, however, remained increased at dismissal. The extent, composition, and distribution of volume overload are highly variable in DCHF, and this variability needs to be taken into account in the approach to individualized therapy. TBV quantitation, particularly serial measurements, can facilitate informed volume management with respect to a goal of treating to euvolemia. Copyright © 2014 American College of Cardiology Foundation. Published

  11. Volumetric Spectroscopic Imaging of Glioblastoma Multiforme Radiation Treatment Volumes

    Energy Technology Data Exchange (ETDEWEB)

    Parra, N. Andres [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States); Maudsley, Andrew A. [Department of Radiology, University of Miami Miller School of Medicine, Miami, Florida (United States); Gupta, Rakesh K. [Department of Radiology and Imaging, Fortis Memorial Research Institute, Gurgaon, Haryana (India); Ishkanian, Fazilat; Huang, Kris [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States); Walker, Gail R. [Biostatistics and Bioinformatics Core Resource, Sylvester Cancer Center, University of Miami Miller School of Medicine, Miami, Florida (United States); Padgett, Kyle [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States); Department of Radiology, University of Miami Miller School of Medicine, Miami, Florida (United States); Roy, Bhaswati [Department of Radiology and Imaging, Fortis Memorial Research Institute, Gurgaon, Haryana (India); Panoff, Joseph; Markoe, Arnold [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States); Stoyanova, Radka, E-mail: RStoyanova@med.miami.edu [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States)

    2014-10-01

    Purpose: Magnetic resonance (MR) imaging and computed tomography (CT) are used almost exclusively in radiation therapy planning of glioblastoma multiforme (GBM), despite their well-recognized limitations. MR spectroscopic imaging (MRSI) can identify biochemical patterns associated with normal brain and tumor, predominantly by observation of choline (Cho) and N-acetylaspartate (NAA) distributions. In this study, volumetric 3-dimensional MRSI was used to map these compounds over a wide region of the brain and to evaluate metabolite-defined treatment targets (metabolic tumor volumes [MTV]). Methods and Materials: Volumetric MRSI with effective voxel size of ∼1.0 mL and standard clinical MR images were obtained from 19 GBM patients. Gross tumor volumes and edema were manually outlined, and clinical target volumes (CTVs) receiving 46 and 60 Gy were defined (CTV{sub 46} and CTV{sub 60}, respectively). MTV{sub Cho} and MTV{sub NAA} were constructed based on volumes with high Cho and low NAA relative to values estimated from normal-appearing tissue. Results: The MRSI coverage of the brain was between 70% and 76%. The MTV{sub NAA} were almost entirely contained within the edema, and the correlation between the 2 volumes was significant (r=0.68, P=.001). In contrast, a considerable fraction of MTV{sub Cho} was outside of the edema (median, 33%) and for some patients it was also outside of the CTV{sub 46} and CTV{sub 60}. These untreated volumes were greater than 10% for 7 patients (37%) in the study, and on average more than one-third (34.3%) of the MTV{sub Cho} for these patients were outside of CTV{sub 60}. Conclusions: This study demonstrates the potential usefulness of whole-brain MRSI for radiation therapy planning of GBM and revealed that areas of metabolically active tumor are not covered by standard RT volumes. The described integration of MTV into the RT system will pave the way to future clinical trials investigating outcomes in patients treated based on

  12. Improving observational study estimates of treatment effects using joint modeling of selection effects and outcomes: the case of AAA repair.

    Science.gov (United States)

    O'Malley, A James; Cotterill, Philip; Schermerhorn, Marc L; Landon, Bruce E

    2011-12-01

    When 2 treatment approaches are available, there are likely to be unmeasured confounders that influence choice of procedure, which complicates estimation of the causal effect of treatment on outcomes using observational data. To estimate the effect of endovascular (endo) versus open surgical (open) repair, including possible modification by institutional volume, on survival after treatment for abdominal aortic aneurysm, accounting for observed and unobserved confounding variables. Observational study of data from the Medicare program using a joint model of treatment selection and survival given treatment to estimate the effects of type of surgery and institutional volume on survival. We studied 61,414 eligible repairs of intact abdominal aortic aneurysms during 2001 to 2004. The outcome, perioperative death, is defined as in-hospital death or death within 30 days of operation. The key predictors are use of endo, transformed endo and open volume, and endo-volume interactions. There is strong evidence of nonrandom selection of treatment with potential confounding variables including institutional volume and procedure date, variables not typically adjusted for in clinical trials. The best fitting model included heterogeneous transformations of endo volume for endo cases and open volume for open cases as predictors. Consistent with our hypothesis, accounting for unmeasured selection reduced the mortality benefit of endo. The effect of endo versus open surgery varies nonlinearly with endo and open volume. Accounting for institutional experience and unmeasured selection enables better decision-making by physicians making treatment referrals, investigators evaluating treatments, and policy makers.

  13. Long-term, low-level radwaste volume-reduction strategies. Volume 4. Waste disposal costs. Final report

    International Nuclear Information System (INIS)

    Sutherland, A.A.; Adam, J.A.; Rogers, V.C.; Merrell, G.B.

    1984-11-01

    Volume 4 establishes pricing levels at new shallow land burial grounds. The following conclusions can be drawn from the analyses described in the preceding chapters: Application of volume reduction techniques by utilities can have a significant impact on the volumes of wastes going to low-level radioactive waste disposal sites. Using the relative waste stream volumes in NRC81 and the maximum volume reduction ratios provided by Burns and Roe, Inc., it was calculated that if all utilities use maximum volume reduction the rate of waste receipt at disposal sites will be reduced by 40 percent. When a disposal site receives a lower volume of waste its total cost of operation does not decrease by the same proportion. Therefore the average cost for a unit volume of waste received goes up. Whether the disposal site operator knows in advance that he will receive a smaller amount of waste has little influence on the average unit cost ($/ft) of the waste disposed. For the pricing algorithm postulated, the average disposal cost to utilities that volume reduce is relatively independent of whether all utilities practice volume reduction or only a few volume reduce. The general effect of volume reduction by utilities is to reduce their average disposal site costs by a factor of between 1.5 to 2.5. This factor is generally independent of the size of the disposal site. The largest absolute savings in disposal site costs when utilities volume reduce occurs when small disposal sites are involved. This results from the fact that unit costs are higher at small sites. Including in the pricing algorithm a factor that penalizes waste generators who contribute larger amounts of the mobile nuclides 3 H, 14 C, 99 Tc, and 129 I, which may be the subject of site inventory limits, lowers unit disposal costs for utility wastes that contain only small amounts of the nuclides and raises unit costs for other utility wastes

  14. Tumor volume in subcutaneous mouse xenografts measured by microCT is more accurate and reproducible than determined by 18F-FDG-microPET or external caliper

    DEFF Research Database (Denmark)

    Jensen, Mette Munk; Jørgensen, Jesper Tranekjaer; Binderup, Tina

    2008-01-01

    BACKGROUND: In animal studies tumor size is used to assess responses to anticancer therapy. Current standard for volumetric measurement of xenografted tumors is by external caliper, a method often affected by error. The aim of the present study was to evaluate if microCT gives more accurate...... (n = 20) was determined in vivo by external caliper, microCT and 18F-FDG-PET and subsequently reference volume was determined ex vivo. Intra-observer reproducibility of the microCT and caliper methods were determined by acquiring 10 repeated volume measurements. Volumes of a group of tumors (n = 10......) were determined independently by two observers to assess inter-observer variation. RESULTS: Tumor volume measured by microCT, PET and caliper all correlated with reference volume. No significant bias of microCT measurements compared with the reference was found, whereas both PET and caliper had...

  15. Significance of breast boost volume changes during radiotherapy in relation to current clinical interobserver variations

    International Nuclear Information System (INIS)

    Hurkmans, Coen; Admiraal, Marjan; Sangen, Maurice van der; Dijkmans, Ingrid

    2009-01-01

    Background and purpose: Nowadays, many departments introduce CT images for breast irradiation techniques, aiming to obtain a better accuracy in the definition of the relevant target volumes. However, the definition of the breast boost volume based on CT images requires further investigation, because it may not only vary between observers, but it may also change during the course of treatment. This study aims to quantify the variability of the CT based visible boost volume (VBV) during the course of treatment in relation to the variability between observers. Materials and methods: Ten patients with stage T1-2 invasive breast cancer treated with breast conservative surgery and post surgical radiotherapy were included in this study. In addition to the regular planning CT which is obtained several days prior to radiotherapy, three additional CT scans were acquired 3, 5 and 7 weeks after the planning CT scan. Four radiation oncologists delineated the VBV in all scans. Conformity of the delineations was analysed both between observers, and between scans taken at different periods of the radiotherapy treatment. Results: The VBV averaged over all patients decreased during the course of the treatment from an initial 40 cm 3 to 28 cm 3 , 27 cm 3 and 25 cm 3 after 3, 5 and 7 weeks, respectively. Assuming the VBV to be spherical, this corresponds to a reduction in diameter of 5-6 mm. More detailed analysis revealed that this reduction was more pronounced when radiotherapy started within 30 days after surgery. These boost volume changes over time were found to be significant (p = 0.02) even in the presence of interobserver variations. Moreover, the conformity index (CI) for the volume changes was of the same magnitude as the conformity index for the interobserver variation (0.25 and 0.31, respectively). Conclusions: Breast boost volume variations during a course of radiotherapy are significant in relation to current clinical interobserver variations. This is an important

  16. The volume of a soliton

    International Nuclear Information System (INIS)

    Adam, C.; Haberichter, M.; Wereszczynski, A.

    2016-01-01

    There exists, in general, no unique definition of the size (volume, area, etc., depending on dimension) of a soliton. Here we demonstrate that the geometric volume (area etc.) of a soliton is singled out in the sense that it exactly coincides with the thermodynamical or continuum-mechanical volume. In addition, this volume may be defined uniquely for rather arbitrary solitons in arbitrary dimensions.

  17. The volume of a soliton

    Energy Technology Data Exchange (ETDEWEB)

    Adam, C., E-mail: adam@fpaxp1.usc.es [Departamento de Física de Partículas, Universidad de Santiago de Compostela and Instituto Galego de Física de Altas Enerxias (IGFAE), E-15782 Santiago de Compostela (Spain); Haberichter, M. [School of Mathematics, Statistics and Actuarial Science, University of Kent, Canterbury, CT2 7NF (United Kingdom); Wereszczynski, A. [Institute of Physics, Jagiellonian University, Lojasiewicza 11, Kraków (Poland)

    2016-03-10

    There exists, in general, no unique definition of the size (volume, area, etc., depending on dimension) of a soliton. Here we demonstrate that the geometric volume (area etc.) of a soliton is singled out in the sense that it exactly coincides with the thermodynamical or continuum-mechanical volume. In addition, this volume may be defined uniquely for rather arbitrary solitons in arbitrary dimensions.

  18. Proper Measurement of the Prostate Volume by Transrectal Ultrasound: Experimental Study about the Prostate with Focal Intravesical Protrusion of the Enlarged Central Gland

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Sung Kyoung; Kim, Hyoung Jung; Lim, Joo Won; Lee, Dong Ho; Ko, Young Tae [Kyung Hee University Hospital, Seoul (Korea, Republic of)

    2008-06-15

    To evaluate the proper volume measurement of prostate with focal intravesical protrusion of enlarged central gland by comparison between methods using craniocaudal length from top of protruded central gland and from prostate base near bladder neck to prostate apex. We made 20 prostate models with focal intravesical protrusion (volume range: 20{approx}50 mL, height of protrusion: about 1 cm) using devil's tongue jelly. Two radiologists measured volume of models 3 times by two kinds of methods using craniocaudal length from top of protruded central gland (method 1) and from prostate base near bladder neck (method 2) by transrectal ultrasound. The accuracy of volume measurement of models was evaluated statistically by comparing their average volume to true volume. Intra- and interobserver agreement was also evaluated. Average true volume of models was 31.05 mL. Each average volume using method 1 by two observers was 37.07 mL and 38.56 mL. Each average volume using method 2 was 30.69 mL and 31.55 mL. Volume measurement using method 2 was approximated to true volume of prostate statistically (p = .654, .823). There was no significant inter- and intra-observer variation in both methods. To measure the accurate volume of prostate with focal intravesical protrusion of enlarged central gland, its craniocaudal length should be measured from prostate base near bladder neck

  19. Postoperative volume balance

    DEFF Research Database (Denmark)

    Frost, H; Mortensen, C.R.; Secher, Niels H.

    2017-01-01

    In healthy humans, stroke volume (SV) and cardiac output (CO) do not increase with expansion of the central blood volume by head-down tilt or administration of fluid. Here, we exposed 85 patients to Trendelenburg's position about one hour after surgery while cardiovascular variables were determin...

  20. Dosimetric impact of the variation of the prostate volume and shape between pretreatment planning and treatment procedure

    International Nuclear Information System (INIS)

    Beaulieu, Luc; Aubin, Sylviane; Taschereau, Richard; Pouliot, Jean; Vigneault, Eric

    2002-01-01

    Purpose: The goal of this study is to evaluate the dosimetric impact on a pretreatment planning of prostatic volume and shape variations occurring between the moment of the volume study (preplanning) and just before a transperineal permanent seed implant procedure. Such variations could be an obvious source of misplacement of the seeds relative to the prostate gland and organs at risk. Other sources of dosimetric uncertainties, such as misplacement due to the procedure itself or edema, are eliminated by looking at these variations before the implant procedure. Methods and Materials: For 35 clinical cases, prostate contours were taken at preplanning time as well as in the operating room (OR) minutes before the procedure. Comparison of shape and volume between the two sets was made. The impact on V100 was evaluated by placing the seeds in their planned positions in the new volume (clinical situation) and also by performing a new plan with the second set of contours to simulate an intraoperative approach. Results: The volume taken in the OR remained unchanged compared to the pretreatment planning volume in only 37% of the cases. While on average the dose coverage loss from pretreatment planning due to a combination of variations of volume and shape was small at 5.7%, a V100 degradation of up to 20.9% was observed in extreme cases. Even in cases in which no changes in volume were observed, changes in shape occurred and strongly affected implant dosimetry. Conclusions: Variations of volume and shape between pretreatment planning and the implant procedure can have a strong impact on the dosimetry if the planning and the implant procedure are not performed on the same day. This is an argument in favor of performing implant dosimetry in the OR

  1. Ovarian volume throughout life

    DEFF Research Database (Denmark)

    Kelsey, Thomas W; Dodwell, Sarah K; Wilkinson, A Graham

    2013-01-01

    conception to 82 years of age. This model shows that 69% of the variation in ovarian volume is due to age alone. We have shown that in the average case ovarian volume rises from 0.7 mL (95% CI 0.4-1.1 mL) at 2 years of age to a peak of 7.7 mL (95% CI 6.5-9.2 mL) at 20 years of age with a subsequent decline...... to about 2.8 mL (95% CI 2.7-2.9 mL) at the menopause and smaller volumes thereafter. Our model allows us to generate normal values and ranges for ovarian volume throughout life. This is the first validated normative model of ovarian volume from conception to old age; it will be of use in the diagnosis......The measurement of ovarian volume has been shown to be a useful indirect indicator of the ovarian reserve in women of reproductive age, in the diagnosis and management of a number of disorders of puberty and adult reproductive function, and is under investigation as a screening tool for ovarian...

  2. Volume weighting the measure of the universe from classical slow-roll expansion

    Science.gov (United States)

    Sloan, David; Silk, Joseph

    2016-05-01

    One of the most frustrating issues in early universe cosmology centers on how to reconcile the vast choice of universes in string theory and in its most plausible high energy sibling, eternal inflation, which jointly generate the string landscape with the fine-tuned and hence relatively small number of universes that have undergone a large expansion and can accommodate observers and, in particular, galaxies. We show that such observations are highly favored for any system whereby physical parameters are distributed at a high energy scale, due to the conservation of the Liouville measure and the gauge nature of volume, asymptotically approaching a period of large isotropic expansion characterized by w =-1 . Our interpretation predicts that all observational probes for deviations from w =-1 in the foreseeable future are doomed to failure. The purpose of this paper is not to introduce a new measure for the multiverse, but rather to show how what is perhaps the most natural and well-known measure, volume weighting, arises as a consequence of the conservation of the Liouville measure on phase space during the classical slow-roll expansion.

  3. Metabolic evaluation and measurement of ovarian volume in polycystic ovary sydrome: a cross-sectional observational study

    Directory of Open Access Journals (Sweden)

    Mehtap Evran

    2016-03-01

    Full Text Available Purpose: Polycystic ovary sydrome is a disease of women in reproductive period, with hirsutism or hyperandrogenic signs in laboratory evaluation, causing infertility due to dysmenorrhea and unovulation. Accompanying insulin resistance and adiposity may increase cardiometabolic risk. In our study, we planned to represent the physical examination and laboratory findings of the patients diagnosed as polycystic ovary sydrome, together with andominal ultrasonographic evaluation of the ovaries. Material-methods: Twenty-two patients who admitted the endocrinology department with the complaints of hirsutism and dysmenorrhea were included in the study. Purpose: Polycystic ovary sydrome is a disease of women in reproductive period, with hirsutism or hyperandrogenic signs in laboratory evaluation, causing infertility due to dysmenorrhea and unovulation. Accompanying insulin resistance and adiposity may increase cardiometabolic risk. In our study, we planned to represent the physical examination and laboratory findings of the patients diagnosed as polycystic ovary sydrome, together with andominal ultrasonographic evaluation of the ovaries. Material and Methods: Twenty-two patients who admitted the endocrinology department with the complaints of hirsutism and dysmenorrhea were included in the study. Their ages, family histories, polycystic ovary sydrome phenotypes, first menstrual age, length of cyclus and physical examination findings were recorded. Ferriman and Gallwey score was used for hirsutism. Insulin resistance was calculated via HOMA-IR method by making the biochemical and hormonal tests. Ovarian volumes were measured by abdominal ultrasonography. SPSS-16 was used for the statistical analysis of the findings. Results: Mean age was 21.41+/-0.88. Polycystic ovary sydrome phenotypes were B in 40.9%, C in 31.8% and A in 27.3%. Cyclus length was normal in 31.8% (27-34 days. Ferriman and Gallwey score was and #8805;7 in all of the patients. Although

  4. The effects of free volumes on charge carrier transport in polysilanes probed by positron annihilation

    International Nuclear Information System (INIS)

    Seki, Shu; Terashima, Y.; Kunimi, Y.; Kawamori, T.; Tashiro, M.; Honda, Y.; Tagawa, S.

    2003-01-01

    Free volume characteristics were investigated by positron annihilation technique in poly(n-alkylphenylsilane)s with a variety length of n-alkyl chains from methyl (C1) to n-dodecyl (C12). The average radius of free volume: R changes in two steps. An increase in R is observed with an elongation of n-alkyl side-groups from C1 to n-pentyl (C5), followed by an abrupt decrease in R between C5 and n-hexyl (C6), and a gradual increase by further elongation from C6 to C12. The sudden decrease in R at C5 and C6 gives a good interpretation to the reduction of inter-site hopping distances and their fluctuation for the charge carrier (hole) transport estimated by time-of-flight measurements. The values of free volume fraction in the polymers mainly reflect the density of the polymers; however, differences in the microscopic inter-molecular structure are also observed for poly(n-hexylphenylsilane) in the present study

  5. Prognostic and predictive value of liver volume on colorectal cancer patients with unresectable liver metastases

    International Nuclear Information System (INIS)

    Park, Jun Su; Park, Hee Chul; Choi, Doo Ho; Park, Won; Yu, Jeong Il; Park, Young Suk; Kang, Won Ki; Park, Joon Oh

    2014-01-01

    To determine the prognostic and predictive value of liver volume in colorectal cancer patients with unresectable liver metastases. Sixteen patients received whole liver radiotherapy (WLRT) between January 1997 and June 2013. A total dose of 21 Gy was delivered in 7 fractions. The median survival time after WLRT was 9 weeks. In univariate analysis, performance status, serum albumin and total bilirubin level, liver volume and extrahepatic metastases were associated with survival. The mean liver volume was significantly different between subgroups with and without pain relief (3,097 and 4,739 mL, respectively; p = 0.002). A larger liver volume is a poor prognostic factor for survival and also a negative predictive factor for response to WLRT. If patients who are referred for WLRT have large liver volume, they should be informed of the poor prognosis and should be closely observed during and after WLRT.

  6. Prognostic and predictive value of liver volume on colorectal cancer patients with unresectable liver metastases

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jun Su; Park, Hee Chul; Choi, Doo Ho; Park, Won; Yu, Jeong Il; Park, Young Suk; Kang, Won Ki; Park, Joon Oh [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2014-06-15

    To determine the prognostic and predictive value of liver volume in colorectal cancer patients with unresectable liver metastases. Sixteen patients received whole liver radiotherapy (WLRT) between January 1997 and June 2013. A total dose of 21 Gy was delivered in 7 fractions. The median survival time after WLRT was 9 weeks. In univariate analysis, performance status, serum albumin and total bilirubin level, liver volume and extrahepatic metastases were associated with survival. The mean liver volume was significantly different between subgroups with and without pain relief (3,097 and 4,739 mL, respectively; p = 0.002). A larger liver volume is a poor prognostic factor for survival and also a negative predictive factor for response to WLRT. If patients who are referred for WLRT have large liver volume, they should be informed of the poor prognosis and should be closely observed during and after WLRT.

  7. East African Journal of Sciences (2015) Volume 9 (1) 41-48 Effect of ...

    African Journals Online (AJOL)

    tosheba

    East African Journal of Sciences (2015). Volume 9 (1) 41-48 ... but no significant difference was observed amongst them. Queen .... used method of termite management in western. Ethiopia ..... Ethiopia. Working Document Series 68, ICRA,.

  8. Environmental report 1995. Volume 2

    International Nuclear Information System (INIS)

    Harrach, R.J.; Failor, R.A.; Gallegos, G.M.

    1996-09-01

    This is Volume 2 of the Lawrence Livermore National Laboratory's (LLNL's) annual Environmental Report 1995. This volume is intended to support summary data from Volume 1 and is essentially a detailed data report that provides additional data points, where applicable. Some summary data are also included in Volume 2, and more detailed accounts are given of sample collection and analytical methods. Volume 2 includes information in eight chapters on monitoring of air, air effluent, sewage, surface water, ground water, soil and sediment, vegetation and foodstuff, and environmental radiation, as well as three chapters on ground water protection, compliance self-monitoring and quality assurance

  9. Psychopathic traits are associated with cortical and subcortical volume alterations in healthy individuals.

    Science.gov (United States)

    Vieira, Joana B; Ferreira-Santos, Fernando; Almeida, Pedro R; Barbosa, Fernando; Marques-Teixeira, João; Marsh, Abigail A

    2015-12-01

    Research suggests psychopathy is associated with structural brain alterations that may contribute to the affective and interpersonal deficits frequently observed in individuals with high psychopathic traits. However, the regional alterations related to different components of psychopathy are still unclear. We used voxel-based morphometry to characterize the structural correlates of psychopathy in a sample of 35 healthy adults assessed with the Triarchic Psychopathy Measure. Furthermore, we examined the regional grey matter alterations associated with the components described by the triarchic model. Our results showed that, after accounting for variation in total intracranial volume, age and IQ, overall psychopathy was negatively associated with grey matter volume in the left putamen and amygdala. Additional regression analysis with anatomical regions of interests revealed total triPM score was also associated with increased lateral orbitofrontal cortex (OFC) and caudate volume. Boldness was positively associated with volume in the right insula. Meanness was positively associated with lateral OFC and striatum volume, and negatively associated with amygdala volume. Finally, disinhibition was negatively associated with amygdala volume. Results highlight the contribution of both subcortical and cortical brain alterations for subclinical psychopathy and are discussed in light of prior research and theoretical accounts about the neurobiological bases of psychopathic traits. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  10. High volume improves outcomes: The argument for centralization of rectal cancer surgery.

    Science.gov (United States)

    Aquina, Christopher T; Probst, Christian P; Becerra, Adan Z; Iannuzzi, James C; Kelly, Kristin N; Hensley, Bradley J; Rickles, Aaron S; Noyes, Katia; Fleming, Fergal J; Monson, John R T

    2016-03-01

    Centralization of care to "centers of excellence" in Europe has led to improved oncologic outcomes; however, little is known regarding the impact of nonmandated regionalization of rectal cancer care in the United States. The Statewide Planning and Research Cooperative System (SPARCS) was queried for elective abdominoperineal and low anterior resections for rectal cancer from 2000 to 2011 in New York with the use of International Classification of Diseases, Ninth Revision codes. Surgeon volume and hospital volume were grouped into quartiles, and high-volume surgeons (≥ 10 resections/year) and hospitals (≥ 25 resections/year) were defined as the top quartile of annual caseload of rectal cancer resection and compared with the bottom 3 quartiles during analyses. Bivariate and multilevel regression analyses were performed to assess factors associated with restorative procedures, 30-day mortality, and temporal trends in these endpoints. Among 7,798 rectal cancer resections, the overall rate of no-restorative proctectomy and 30-day mortality decreased by 7.7% and 1.2%, respectively, from 2000 to 2011. In addition, there was a linear increase in the proportion of cases performed by both high-volume surgeons and high-volume hospitals and a decrease in the number of surgeons and hospitals performing rectal cancer surgery. High-volume surgeons at high-volume hospitals were associated independently with both less nonrestorative proctectomies (odds ratio 0.65, 95% confidence interval 0.48-0.89) and mortality (odds ratio 0.43, 95% confidence interval 0.21-0.87) rates. No patterns of significant improvement within the volume strata of the surgeon and hospitals were observed over time. This study suggests that the current trend toward regionalization of rectal cancer care to high-volume surgeons and high-volume centers has led to improved outcomes. These findings have implications regarding the policy of health care delivery in the United States, supporting referral to high-volume

  11. Trends in laboratory test volumes for Medicare Part B reimbursements, 2000-2010.

    Science.gov (United States)

    Shahangian, Shahram; Alspach, Todd D; Astles, J Rex; Yesupriya, Ajay; Dettwyler, William K

    2014-02-01

    Changes in reimbursements for clinical laboratory testing may help us assess the effect of various variables, such as testing recommendations, market forces, changes in testing technology, and changes in clinical or laboratory practices, and provide information that can influence health care and public health policy decisions. To date, however, there has been no report, to our knowledge, of longitudinal trends in national laboratory test use. To evaluate Medicare Part B-reimbursed volumes of selected laboratory tests per 10,000 enrollees from 2000 through 2010. Laboratory test reimbursement volumes per 10,000 enrollees in Medicare Part B were obtained from the Centers for Medicare & Medicaid Services (Baltimore, Maryland). The ratio of the most recent (2010) reimbursed test volume per 10,000 Medicare enrollees, divided by the oldest data (usually 2000) during this decade, called the volume ratio, was used to measure trends in test reimbursement. Laboratory tests with a reimbursement claim frequency of at least 10 per 10,000 Medicare enrollees in 2010 were selected, provided there was more than a 50% change in test reimbursement volume during the 2000-2010 decade. We combined the reimbursed test volumes for the few tests that were listed under more than one code in the Current Procedural Terminology (American Medical Association, Chicago, Illinois). A 2-sided Poisson regression, adjusted for potential overdispersion, was used to determine P values for the trend; trends were considered significant at P reimbursement volumes were electrolytes, digoxin, carbamazepine, phenytoin, and lithium, with volume ratios ranging from 0.27 to 0.64 (P reimbursement volumes were meprobamate, opiates, methadone, phencyclidine, amphetamines, cocaine, and vitamin D, with volume ratios ranging from 83 to 1510 (P reimbursement volumes increased for most of the selected tests, other tests exhibited statistically significant downward trends in annual reimbursement volumes. The observed

  12. A 3-Year Study of Self-Regulation in Montessori and Non-Montessori Classrooms

    Science.gov (United States)

    Ervin, Barbara; Wash, Pamela D.; Mecca, Marilyn E.

    2010-01-01

    Albert Bandura, the leading pioneer in the study of self-regulation, has defined the term as the child's ability to self-educate, self-direct, regulate motivation, and learn to think about what she is learning (1994). Lev Vygotsky's theory that children can be taught to think independently about how to solve problems expands upon Bandura's work…

  13. Water retention behaviour of compacted bentonites: experimental observations and constitutive model

    Directory of Open Access Journals (Sweden)

    Dieudonne Anne-Catherine

    2016-01-01

    Full Text Available Bentonite-based materials are studied as potential barriers for the geological disposal of radioactive waste. In this context, the hydro-mechanical behaviour of the engineered barrier is first characterized by free swelling conditions followed by constant volume conditions. This paper presents an experimental study conducted in order to characterize the water retention behaviour of a compacted MX-80 bentonite/sand mixture. Then, based on observations of the material double structure and the water retention mechanisms in compacted bentonites, a new water retention model is proposed. The model considers adsorbed water in the microstructure and capillary water in the aggregate-porosity. The model is calibrated and validated against the experimental data. It is used for better understanding competing effects between volume change and water uptake observed during hydration under free swelling conditions.

  14. Naturally light hidden photons in LARGE volume string compactifications

    International Nuclear Information System (INIS)

    Goodsell, M.; Jaeckel, J.; Redondo, J.; Ringwald, A.

    2009-09-01

    Extra ''hidden'' U(1) gauge factors are a generic feature of string theory that is of particular phenomenological interest. They can kinetically mix with the Standard Model photon and are thereby accessible to a wide variety of astrophysical and cosmological observations and laboratory experiments. In this paper we investigate the masses and the kinetic mixing of hidden U(1)s in LARGE volume compactifications of string theory. We find that in these scenarios the hidden photons can be naturally light and that their kinetic mixing with the ordinary electromagnetic photon can be of a size interesting for near future experiments and observations. (orig.)

  15. Evaluation of atlas based auto-segmentation for head and neck target volume delineation in adaptive/replan IMRT

    International Nuclear Information System (INIS)

    Speight, R; Lindsay, R; Harding, R; Sykes, J; Karakaya, E; Prestwich, R; Sen, M

    2014-01-01

    IMRT for head and neck patients requires clinicians to delineate clinical target volumes (CTV) on a planning-CT (>2hrs/patient). When patients require a replan-CT, CTVs must be re-delineated. This work assesses the performance of atlas-based autosegmentation (ABAS), which uses deformable image registration between planning and replan-CTs to auto-segment CTVs on the replan-CT, based on the planning contours. Fifteen patients with planning-CT and replan-CTs were selected. One clinician delineated CTVs on the planning-CTs and up to three clinicians delineated CTVs on the replan-CTs. Replan-CT volumes were auto-segmented using ABAS using the manual CTVs from the planning-CT as an atlas. ABAS CTVs were edited manually to make them clinically acceptable. Clinicians were timed to estimate savings using ABAS. CTVs were compared using dice similarity coefficient (DSC) and mean distance to agreement (MDA). Mean inter-observer variability (DSC>0.79 and MDA<2.1mm) was found to be greater than intra-observer variability (DSC>0.91 and MDA<1.5mm). Comparing ABAS to manual CTVs gave DSC=0.86 and MDA=2.07mm. Once edited, ABAS volumes agreed more closely with the manual CTVs (DSC=0.87 and MDA=1.87mm). The mean clinician time required to produce CTVs reduced from 169min to 57min when using ABAS. ABAS segments volumes with accuracy close to inter-observer variability however the volumes require some editing before clinical use. Using ABAS reduces contouring time by a factor of three.

  16. Prospective randomized double-blind pilot study of site-specific consensus atlas implementation for rectal cancer target volume delineation in the cooperative group setting

    Science.gov (United States)

    Fuller, Clifton D.; Nijkamp, Jasper; Duppen, Joop; Rasch, Coen R.N.; Thomas, Charles R.; Wang, Samuel J.; Okunieff, Paul; Jones, William E.; Baseman, Daniel; Patel, Shilpen; Demandante, Carlo G. N.; Harris, Anna M.; Smith, Benjamin D.; Katz, Alan W.; McGann, Camille; Harper, Jennifer L.; Chang, Daniel T.; Smalley, Stephen; Marshall, David T.; Goodman, Karyn A.; Papanikolaou, Niko; Kachnic, Lisa A.

    2010-01-01

    Purpose Variation in target volume delineation represents a significant hurdle in clinical trials involving conformal radiotherapy. We sought to determine the impact of a consensus guideline-based visual atlas on contouring of target volumes. Methods A representative case and target volume delineation instructions derived from a proposed rectal cancer clinical trial involving conformal radiotherapy were contoured (Scan1) by 14 physician observers and a reference expert. Gross tumor volume (GTV), and 2 clinical target volumes (CTVA, comprising internal iliac, pre-sacral, and peri-rectal nodes, and CTVB, external iliac nodes) were contoured. Observers were randomly assigned to receipt (Group_A) /non-receipt (Group_B) of a consensus guideline and atlas for anorectal cancers, then instructed to re-contour the same case/images (Scan2). Observer variation was analyzed volumetrically using conformation number (CN, where CN=1 equals a total agreement). Results In 14 evaluable contour sets (1 expert, 7 Group_A, 6 Group_B), there was greater agreement for GTV (mean CN 0.75) than CTVs (mean CN 0.46–0.65). Atlas exposure for Group_A led to a significant increased inter-observer agreement for CTVA (mean initial CN 0.68, post-atlas 0.76; p=0.03), as well as increased agreement with the expert reference (initial mean CN 0.58, 0.69 post-atlas; p=0.02). For GTV and CTVB, neither inter-observer nor expert agreement was altered after atlas exposure. Conclusion Consensus guideline atlas implementation resulted in a detectable difference in inter-observer agreement and greater approximation of expert volumes for CTVA, but not GTV or CTVB, in the specified case. Visual atlas inclusion should be considered as a feature in future clinical trials incorporating conformal radiotherapy. PMID:20400244

  17. Variable volume combustor

    Science.gov (United States)

    Ostebee, Heath Michael; Ziminsky, Willy Steve; Johnson, Thomas Edward; Keener, Christopher Paul

    2017-01-17

    The present application provides a variable volume combustor for use with a gas turbine engine. The variable volume combustor may include a liner, a number of micro-mixer fuel nozzles positioned within the liner, and a linear actuator so as to maneuver the micro-mixer fuel nozzles axially along the liner.

  18. Analgesic efficacy of local anaesthetic wound administration in knee arthroplasty: volume vs concentration

    DEFF Research Database (Denmark)

    Andersen, L Ø; Gaarn-Larsen, L; Kristensen, B B

    2010-01-01

    was reduced in both groups with ropivacaine administration 24 h postoperatively (p time intervals. No reduction in pain scores was observed with ropivacaine injection 6 h postoperatively. The median (IQR [range]) dose of oxycodone administered......Wound administration of local anaesthetic may be effective for postoperative pain management in knee arthroplasty, but the analgesic efficacy of local anaesthetic in relation to volume vs concentration has not been determined. In a double-blinded trial, 48 patients scheduled for total knee...... arthroplasty were randomly assigned to receive either a high volume/low concentration solution of ropivacaine (20 ml, 0.5%) or a low volume/high concentration solution of ropivacaine (10 ml, 1%), 6 and 24 h postoperatively through an intracapsular catheter. Pain was assessed for 2 h after administration. Pain...

  19. Post-traumatic stress and age variation in amygdala volumes among youth exposed to trauma.

    Science.gov (United States)

    Weems, Carl F; Klabunde, Megan; Russell, Justin D; Reiss, Allan L; Carrión, Victor G

    2015-12-01

    Theoretically, normal developmental variation in amygdala volumes may be altered under conditions of severe stress. The purpose of this article was to examine whether posttraumatic stress moderates the association between age and amygdala volumes in youth exposed to traumatic events who are experiencing symptoms of post-traumatic stress disorder (PTSD). Volumetric imaging was conducted on two groups of youth aged 9-17 years: 28 with exposure to trauma and PTSD symptoms (boys = 15, girls = 13) and 26 matched (age, IQ) comparison youth (Controls; boys = 12, girls = 14). There was a significant group by age interaction in predicting right amygdala volumes. A positive association between age and right amygdala volumes was observed, but only in PTSD youth. These associations with age remained when controlling for IQ, total brain volumes and sex. Moreover, older youth with PTSD symptoms had relatively larger right amygdala volumes than controls. Findings provide evidence that severe stress may influence age-related variation in amygdala volumes. Results further highlight the importance of utilizing age as an interactive variable in pediatric neuroimaging research, in so far as age may act as an important moderator of group differences. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  20. Feasibility of CBCT-based target and normal structure delineation in prostate cancer radiotherapy: Multi-observer and image multi-modality study

    International Nuclear Information System (INIS)

    Luetgendorf-Caucig, Carola; Fotina, Irina; Stock, Markus; Poetter, Richard; Goldner, Gregor; Georg, Dietmar

    2011-01-01

    Background and purpose: In-room cone-beam CT (CBCT) imaging and adaptive treatment strategies are promising methods to decrease target volumes and to spare organs at risk. The aim of this work was to analyze the inter-observer contouring uncertainties of target volumes and organs at risks (oars) in localized prostate cancer radiotherapy using CBCT images. Furthermore, CBCT contouring was benchmarked against other image modalities (CT, MR) and the influence of subjective image quality perception on inter-observer variability was assessed. Methods and materials: Eight prostate cancer patients were selected. Seven radiation oncologists contoured target volumes and oars on CT, MRI and CBCT. Volumes, coefficient of variation (COV), conformity index (cigen), and coordinates of center-of-mass (COM) were calculated for each patient and image modality. Reliability analysis was performed for the support of the reported findings. Subjective perception of image quality was assessed via a ten-scored visual analog scale (VAS). Results: The median volume for prostate was larger on CT compared to MRI and CBCT images. The inter-observer variation for prostate was larger on CBCT (CIgen = 0.57 ± 0.09, 0.61 reliability) compared to CT (CIgen = 0.72 ± 0.07, 0.83 reliability) and MRI (CIgen = 0.66 ± 0.12, 0.87 reliability). On all image modalities values of the intra-observer reliability coefficient (0.97 for CT, 0.99 for MR and 0.94 for CBCT) indicated high reproducibility of results. For all patients the root mean square (RMS) of the inter-observer standard deviation (σ) of the COM was largest on CBCT with σ(x) = 0.4 mm, σ(y) = 1.1 mm, and σ(z) = 1.7 mm. The concordance in delineating OARs was much stronger than for target volumes, with average CIgen > 0.70 for rectum and CIgen > 0.80 for bladder. Positive correlations between CIgen and VAS score of the image quality were observed for the prostate, seminal vesicles and rectum. Conclusions: Inter-observer variability for target