Millennial Filipino Student Engagement Analyzer Using Facial Feature Classification

Science.gov (United States)

Manseras, R.; Eugenio, F.; Palaoag, T.

2018-03-01

Millennials has been a word of mouth of everybody and a target market of various companies nowadays. In the Philippines, they comprise one third of the total population and most of them are still in school. Having a good education system is important for this generation to prepare them for better careers. And a good education system means having quality instruction as one of the input component indicators. In a classroom environment, teachers use facial features to measure the affect state of the class. Emerging technologies like Affective Computing is one of today’s trends to improve quality instruction delivery. This, together with computer vision, can be used in analyzing affect states of the students and improve quality instruction delivery. This paper proposed a system of classifying student engagement using facial features. Identifying affect state, specifically Millennial Filipino student engagement, is one of the main priorities of every educator and this directed the authors to develop a tool to assess engagement percentage. Multiple face detection framework using Face API was employed to detect as many student faces as possible to gauge current engagement percentage of the whole class. The binary classifier model using Support Vector Machine (SVM) was primarily set in the conceptual framework of this study. To achieve the most accuracy performance of this model, a comparison of SVM to two of the most widely used binary classifiers were tested. Results show that SVM bested RandomForest and Naive Bayesian algorithms in most of the experiments from the different test datasets.

Teaching High School Students Machine Learning Algorithms to Analyze Flood Risk Factors in River Deltas

Science.gov (United States)

Rose, R.; Aizenman, H.; Mei, E.; Choudhury, N.

2013-12-01

High School students interested in the STEM fields benefit most when actively participating, so I created a series of learning modules on how to analyze complex systems using machine-learning that give automated feedback to students. The automated feedbacks give timely responses that will encourage the students to continue testing and enhancing their programs. I have designed my modules to take the tactical learning approach in conveying the concepts behind correlation, linear regression, and vector distance based classification and clustering. On successful completion of these modules, students will learn how to calculate linear regression, Pearson's correlation, and apply classification and clustering techniques to a dataset. Working on these modules will allow the students to take back to the classroom what they've learned and then apply it to the Earth Science curriculum. During my research this summer, we applied these lessons to analyzing river deltas; we looked at trends in the different variables over time, looked for similarities in NDVI, precipitation, inundation, runoff and discharge, and attempted to predict floods based on the precipitation, waves mean, area of discharge, NDVI, and inundation.

Enhancing Mathematics Teachers' Knowledge of Students' Thinking from Assessing and Analyzing Misconceptions in Homework

Science.gov (United States)

An, Shuhua; Wu, Zhonghe

2012-01-01

This study focuses on teacher learning of student thinking through grading homework, assessing and analyzing misconceptions. The data were collected from 10 teachers at fifth-eighth grade levels in the USA. The results show that assessing and analyzing misconceptions from grading homework is an important approach to acquiring knowledge of…

Accuracy of fibula reconstruction using patient-specific CAD/CAM reconstruction plates and dental implants : A new modality for functional reconstruction of mandibular defects

NARCIS (Netherlands)

Schepers, Rutger H.; Raghoebar, Gerry M.; Vissink, Arjan; Stenekes, Martin W.; Kraeima, Joep; Roodenburg, Jan L.; Reintsema, Harry; Witjes, Max J.

Background: The purpose of this study was to analyze the accuracy of mandibular reconstruction using patient-specific computer-aided designed and computer-aided manufactured (CAD/CAM) reconstruction plates as a guide to place fibula grafts and dental implants in a one-stage procedure using

ANALYZING THE RELATIONSHIP BETWEEN PROBLEM SOLVING SKILLS AND PERSONALITY CHARACTERISTICS OF UNIVERSITY STUDENTS

OpenAIRE

SÜLEYMAN DÜNDAR

2013-01-01

The aim of this study is to analyze problem solving skills of university students according to their personal characteristics. We try to find out if there is a difference in problem solving skills considering sex, class and personality harmony characteristics. Personal data form, Problem Solving Scale and Hacettepe Personality Scale are used as measurement tools. The results of the study indicate that there is no difference between male and female students in problem solving skills. Problem s...

Pick Your Poisson: A Tutorial on Analyzing Counts of Student Victimization Data

Science.gov (United States)

Huang, Francis L.; Cornell, Dewey G.

2012-01-01

School violence research is often concerned with infrequently occurring events such as counts of the number of bullying incidents or fights a student may experience. Analyzing count data using ordinary least squares regression may produce improbable predicted values, and as a result of regression assumption violations, result in higher Type I…

Addressing secondary school students' everyday ideas about freshwater springs in order to develop an instructional tool to promote conceptual reconstruction

Science.gov (United States)

Reinfried, S.; Tempelmann, S.; Aeschbacher, U.

2012-05-01

"Water knowledge" has now become a socio-political and future-orientated necessity. Everyday ideas or preconceptions of hydrology can have a deleterious effect one people's understanding of the scientific facts and their interrelations that are of relevance to sustainable water management. This explorative pilot study shows that preconceived notions about the origin of freshwater springs are common at the lower secondary school level. The purpose of this study was two-fold: (1) to investigate the nature of everyday ideas about freshwater springs among 81 13-yr-old Swiss students, and (2) to develop an efficient instructional tool that promotes conceptual reconstruction in the learners' minds. To assess students' everyday ideas we conducted interviews, examined student work, and asked students to fill in a questionnaire. The results indicate that half of the students have some basic hydrological knowledge. However, several preconceived notions that can significantly impede the understanding of hydrological concepts have been found. A common preconception concerns the idea that solid rocks cannot be permeable and that large underground cavities constitute a necessary precondition for the formation of springs. While these ideas may well be true for karst springs they inhibit the understanding of the concept of other spring types due to their plausibility and intelligibility. We therefore chose the concept of the hillslope spring to construct an instructional tool that takes into account the findings of the psychology of learning aimed at promoting deep learning, thus facilitating a lasting conceptual reconstruction of the concept of springs.

Helping Students Analyze Revolutions

Science.gov (United States)

Armstrong, Stephen; Desrosiers, Marian

2012-01-01

A visitor to a random sampling of Modern World History classes in the United States will find that the subject of "revolution" is a favorite for many students. Reading about and researching individuals and topics such as Tsar Nicholas II, Rasputin, Marie Antoinette and guillotines is never boring. Unfortunately, in too many classrooms,…

Increasing efficiency of reconstruction and technological development of coking enterprises

Energy Technology Data Exchange (ETDEWEB)

Rozenfel' d, M.S.; Martynenko, V.M.; Tytyuk, Yu.A.; Ivanov, V.V.; Svyatogorov, A.A.; Kolomiets, A.F. (NIISP, Voroshilovgrad (USSR))

1989-07-01

Discusses problems associated with reconstruction of coking plants in the USSR. Planning coking plant reconstruction is analyzed. Duration of individual stages of plant reconstruction is considered. A method developed by the Giprokoks research institute for calculating reconstruction time considering duration of individual stages of coke oven battery repair is analyzed: construction of storage facilities, transport of materials and equipment, safety requirements, coke oven cooling, dismantling, construction of coke oven walls, installation of machines and equipment. Advantages of using the methods for analysis of coke oven battery reconstruction and optimization of repair time are discussed.

Analyzing Medical Students' Definitions of Sex

Science.gov (United States)

Talley, Heather; Cho, Janice; Strassberg, Donald S.; Rullo, Jordan E.

2016-01-01

An inaccurate definition of what constitutes sex can negatively impact the sexual health and wellbeing of patients. This study aimed to determine which behaviors medical students consider to be sex. Survey questions about various sexual behaviors were administered to medical students. All participants agreed that penile-vaginal penetration is sex.…

How do students react to analyzing their own genomes in a whole-genome sequencing course?: outcomes of a longitudinal cohort study.

Science.gov (United States)

Sanderson, Saskia C; Linderman, Michael D; Zinberg, Randi; Bashir, Ali; Kasarskis, Andrew; Zweig, Micol; Suckiel, Sabrina; Shah, Hardik; Mahajan, Milind; Diaz, George A; Schadt, Eric E

2015-11-01

Health-care professionals need to be trained to work with whole-genome sequencing (WGS) in their practice. Our aim was to explore how students responded to a novel genome analysis course that included the option to analyze their own genomes. This was an observational cohort study. Questionnaires were administered before (T3) and after the genome analysis course (T4), as well as 6 months later (T5). In-depth interviews were conducted at T5. All students (n = 19) opted to analyze their own genomes. At T5, 12 of 15 students stated that analyzing their own genomes had been useful. Ten reported they had applied their knowledge in the workplace. Technical WGS knowledge increased (mean of 63.8% at T3, mean of 72.5% at T4; P = 0.005). In-depth interviews suggested that analyzing their own genomes may increase students' motivation to learn and their understanding of the patient experience. Most (but not all) of the students reported low levels of WGS results-related distress and low levels of regret about their decision to analyze their own genomes. Giving students the option of analyzing their own genomes may increase motivation to learn, but some students may experience personal WGS results-related distress and regret. Additional evidence is required before considering incorporating optional personal genome analysis into medical education on a large scale.

Addressing secondary school students' everyday ideas about freshwater springs in order to develop an instructional tool to promote conceptual reconstruction

Directory of Open Access Journals (Sweden)

S. Reinfried

2012-05-01

Full Text Available "Water knowledge" has now become a socio-political and future-orientated necessity. Everyday ideas or preconceptions of hydrology can have a deleterious effect one people's understanding of the scientific facts and their interrelations that are of relevance to sustainable water management. This explorative pilot study shows that preconceived notions about the origin of freshwater springs are common at the lower secondary school level. The purpose of this study was two-fold: (1 to investigate the nature of everyday ideas about freshwater springs among 81 13-yr-old Swiss students, and (2 to develop an efficient instructional tool that promotes conceptual reconstruction in the learners' minds. To assess students' everyday ideas we conducted interviews, examined student work, and asked students to fill in a questionnaire. The results indicate that half of the students have some basic hydrological knowledge. However, several preconceived notions that can significantly impede the understanding of hydrological concepts have been found. A common preconception concerns the idea that solid rocks cannot be permeable and that large underground cavities constitute a necessary precondition for the formation of springs. While these ideas may well be true for karst springs they inhibit the understanding of the concept of other spring types due to their plausibility and intelligibility. We therefore chose the concept of the hillslope spring to construct an instructional tool that takes into account the findings of the psychology of learning aimed at promoting deep learning, thus facilitating a lasting conceptual reconstruction of the concept of springs.

Analyzing the Cooking Behavior of Sophomore Female Students : In relation to the ability for preparation of cooking

OpenAIRE

Imakawa, Shinji

2012-01-01

The aim of this study was to clarify the Dandori-ryoku (the ability for preparation in cooking) by analyzing the practical cooking behavior of sophomore female students. Ten sophomore female students were participated in the experiment to cook three kinds of food (cooking rice, making miso soup and fried vegetables). The behavior of the participants during cooking were videotaped and analyzed in detail later especially in relation to Dandori-ryoku. Such behaviors as “starting from cooking ric...

Attitudes of Lebanese university students towards surgical hymen reconstruction.

Science.gov (United States)

Awwad, Johnny; Nassar, Anwar; Usta, Ihab; Shaya, Monique; Younes, Zeina; Ghazeeri, Ghina

2013-11-01

Many cultural and religious beliefs place virginity at a high level of social significance, in that women who lose their virginity before marriage may face humiliation, ostracism, divorce, and extreme violence. This led to an increase in the demand for virginity restoration through surgical hymen reconstruction among these cultures. However, data regarding the acceptance of hymenoplasty in societies that consider sexuality a taboo are scarce. In this cross-sectional study, we investigated the effects of gender and religion on sexual attitudes towards hymenoplasty, premarital sex, and virginity in a sample of 600 Lebanese university students. Our findings showed that approval of hymenoplasty was low among participants regardless of gender (25.7 % men vs. 19.1 % women) and religious affiliations (22.5 % Muslims vs. 22.3 % Christians). Arguments for rejection were rooted in moral ethics and personal convictions: "form of deceiving and cheating" (80.7 %) and "betrayal of honesty in the relationship" (80.4 %). Reasons for acceptance included: personal belief in "women's rights, autonomy, and freedom" (72.2 %) and "physical harm and death" (63.5 %).Male participants were more likely to approve premarital coital sex than females (61.0 vs. 27.3 %). Muslims were also more likely to reject marrying a non-virgin than Christians (39.9 vs. 18.0 %). Female participants expressed more tolerance towards marrying a non-virgin male partner (78.3 vs. 57.3 %). Low acceptance of hymenoplasty among Lebanese university students was found to be related to moral ethics and personal convictions independently from gender and religious affiliation. Differences in sexual attitudes towards premarital coital sex and virginity, however, were more significantly influenced by culture and religion.

Assessing High Impact Practices Using NVivo: An Automated Approach to Analyzing Student Reflections for Program Improvement

Science.gov (United States)

Blaney, Jennifer; Filer, Kimberly; Lyon, Julie

2014-01-01

Critical reflection allows students to synthesize their learning and deepen their understanding of an experience (Ash & Clayton, 2009). A recommended reflection method is for students to write essays about their experiences. However, on a large scale, such reflection essays become difficult to analyze in a meaningful way. At Roanoke College,…

Creating Spaces for Reconstructing Knowledge in Feminist Pedagogy.

Science.gov (United States)

Thompson, Audrey; Gitlin, Andrew

1995-01-01

Presents a conceptual outline for a feminist pedagogy that attempts to develop reconstructed knowledge. The paper describes how standpoint theory and conversation as method can further the aim of reconstructed knowledge, arguing that teachers and students with pedagogical relations should seek opportunities to create spaces within which to…

A word-count approach to analyze linguistic patterns in the reflective writings of medical students

Directory of Open Access Journals (Sweden)

Chi-Wei Lin

2016-02-01

Full Text Available Background: Teaching reflection and administering reflective writing assignments to students are widely practiced and discussed in medical education and health professional education. However, little is known about how medical students use language to construct their narratives. Exploring students’ linguistic patterns in their reflective writings can facilitate understanding the scope and facets of their reflections and their representational or communication approaches to share their experiences. Moreover, research findings regarding gender differences in language use are inconsistent. Therefore, we attempted to examine how females and males differ in their use of words in reflective writing within our research circumstance to detect the unique and gender-specific approaches to learning and their applications. Methods: We analyzed the linguistic profiles of psychological process categories in the reflective writings of medical students and examined the difference in word usage between male and female medical students. During the first year of a clinical rotation, 60 fifth-year medical students wrote reflective narratives regarding pediatric patients and the psychosocial challenges faced by the patients and their family members. The narratives were analyzed using the Chinese version of Linguistic Inquiry and Word Count (CLIWC, a text analysis software program. Multivariate procedures were applied for statistical analysis. Results: Cognitive words were most pervasive, averaging 22.16%, whereas perceptual words (2.86% were least pervasive. Female students used more words related to positive emotions and sadness than did male students. The male students exceeded the female students only in the space category. The major limitation of this study is that CLIWC cannot directly acquire contextual text meanings; therefore, depending on the research topic, further qualitative study of the given texts might be necessary. Conclusions: To enhance students�

Reconstructing and analyzing China's fifty-nine year (1951–2009 drought history using hydrological model simulation

Directory of Open Access Journals (Sweden)

Z. Y. Wu

2011-09-01

and the Northwest, which extends to the southeastern portion of Inner Mongolia and the southwest part of Northeast. The second one is found on the central to southern portion of the South. Our study demonstrates the applicability and the value of using modeled soil moisture for reconstructing drought histories, and the SMAPI is useful for analyzing drought at different spatial and temporal scales.

Testing the predictions of the existential constructivist theory of suicide in a college student sample.

Science.gov (United States)

Lockman, Jennifer D; Servaty-Seib, Heather L

2018-04-01

There is a lack of empirically supported theories explaining suicidal ideation and few theories describe how suicidal ideation can be prevented in the context of normative human development. Rogers (2001) proposed an existential constructivist theory of suicide (ECTS) wherein existential distress and the inability to reconstruct meaning from adverse life events contribute to suicidal ideation. The ECTS includes a distinct focus on meaning reconstruction from adverse life events, which is congruent with existing research on college students and developmental frameworks used by counseling psychologists. Thus, in the present study, we tested the predictions of the ECTS in a college student sample. We collected data online from 195 college students (i.e., ages 18-25) attending a large, Midwestern university and analyzed the data using structural equation modeling. Findings provided partial support for the original ECTS. Post hoc analyses of an alternate ECTS model indicated that existential distress mediated the negative association between meaning reconstruction and suicidal ideation. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

The Binary System Laboratory Activities Based on Students Mental Model

Science.gov (United States)

Albaiti, A.; Liliasari, S.; Sumarna, O.; Martoprawiro, M. A.

2017-09-01

Generic science skills (GSS) are required to develop student conception in learning binary system. The aim of this research was to know the improvement of students GSS through the binary system labotoratory activities based on their mental model using hypothetical-deductive learning cycle. It was a mixed methods embedded experimental model research design. This research involved 15 students of a university in Papua, Indonesia. Essay test of 7 items was used to analyze the improvement of students GSS. Each items was designed to interconnect macroscopic, sub-microscopic and symbolic levels. Students worksheet was used to explore students mental model during investigation in laboratory. The increase of students GSS could be seen in their N-Gain of each GSS indicators. The results were then analyzed descriptively. Students mental model and GSS have been improved from this study. They were interconnect macroscopic and symbolic levels to explain binary systems phenomena. Furthermore, they reconstructed their mental model with interconnecting the three levels of representation in Physical Chemistry. It necessary to integrate the Physical Chemistry Laboratory into a Physical Chemistry course for effectiveness and efficiency.

Sparse Image Reconstruction in Computed Tomography

DEFF Research Database (Denmark)

Jørgensen, Jakob Sauer

In recent years, increased focus on the potentially harmful effects of x-ray computed tomography (CT) scans, such as radiation-induced cancer, has motivated research on new low-dose imaging techniques. Sparse image reconstruction methods, as studied for instance in the field of compressed sensing...... applications. This thesis takes a systematic approach toward establishing quantitative understanding of conditions for sparse reconstruction to work well in CT. A general framework for analyzing sparse reconstruction methods in CT is introduced and two sets of computational tools are proposed: 1...... contributions to a general set of computational characterization tools. Thus, the thesis contributions help advance sparse reconstruction methods toward routine use in...

A cognitive framework for analyzing and describing introductory students' use and understanding of mathematics in physics

Science.gov (United States)

Tuminaro, Jonathan

Many introductory, algebra-based physics students perform poorly on mathematical problem solving tasks in physics. There are at least two possible, distinct reasons for this poor performance: (1) students simply lack the mathematical skills needed to solve problems in physics, or (2) students do not know how to apply the mathematical skills they have to particular problem situations in physics. While many students do lack the requisite mathematical skills, a major finding from this work is that the majority of students possess the requisite mathematical skills, yet fail to use or interpret them in the context of physics. In this thesis I propose a theoretical framework to analyze and describe students' mathematical thinking in physics. In particular, I attempt to answer two questions. What are the cognitive tools involved in formal mathematical thinking in physics? And, why do students make the kinds of mistakes they do when using mathematics in physics? According to the proposed theoretical framework there are three major theoretical constructs: mathematical resources, which are the knowledge elements that are activated in mathematical thinking and problem solving; epistemic games, which are patterns of activities that use particular kinds of knowledge to create new knowledge or solve a problem; and frames, which are structures of expectations that determine how individuals interpret situations or events. The empirical basis for this study comes from videotaped sessions of college students solving homework problems. The students are enrolled in an algebra-based introductory physics course. The videotapes were transcribed and analyzed using the aforementioned theoretical framework. Two important results from this work are: (1) the construction of a theoretical framework that offers researchers a vocabulary (ontological classification of cognitive structures) and grammar (relationship between the cognitive structures) for understanding the nature and origin of

Update on orbital reconstruction.

Science.gov (United States)

Chen, Chien-Tzung; Chen, Yu-Ray

2010-08-01

Orbital trauma is common and frequently complicated by ocular injuries. The recent literature on orbital fracture is analyzed with emphasis on epidemiological data assessment, surgical timing, method of approach and reconstruction materials. Computed tomographic (CT) scan has become a routine evaluation tool for orbital trauma, and mobile CT can be applied intraoperatively if necessary. Concomitant serious ocular injury should be carefully evaluated preoperatively. Patients presenting with nonresolving oculocardiac reflex, 'white-eyed' blowout fracture, or diplopia with a positive forced duction test and CT evidence of orbital tissue entrapment require early surgical repair. Otherwise, enophthalmos can be corrected by late surgery with a similar outcome to early surgery. The use of an endoscope-assisted approach for orbital reconstruction continues to grow, offering an alternative method. Advances in alloplastic materials have improved surgical outcome and shortened operating time. In this review of modern orbital reconstruction, several controversial issues such as surgical indication, surgical timing, method of approach and choice of reconstruction material are discussed. Preoperative fine-cut CT image and thorough ophthalmologic examination are key elements to determine surgical indications. The choice of surgical approach and reconstruction materials much depends on the surgeon's experience and the reconstruction area. Prefabricated alloplastic implants together with image software and stereolithographic models are significant advances that help to more accurately reconstruct the traumatized orbit. The recent evolution of orbit reconstruction improves functional and aesthetic results and minimizes surgical complications.

Analyzing Political Television Advertisements.

Science.gov (United States)

Burson, George

1992-01-01

Presents a lesson plan to help students understand that political advertisements often mislead, lie, or appeal to emotion. Suggests that the lesson will enable students to examine political advertisements analytically. Includes a worksheet to be used by students to analyze individual political advertisements. (DK)

A research project with students of Information and Communication Technology in obligatory secondary education: virtual reconstruction of the thermal area of the roman villa of Balazote (Albacete

Directory of Open Access Journals (Sweden)

Pilar Mediano Serrano

2016-10-01

Full Text Available The optional subject Information and Communication Technology (ICT in obligatory secondary education is fundamentally about how to use applications. The software related to this subject is based on: photo editing programs, 3D constructions, sound editing and video editing. These can be viewed in isolation and independently or as a part of a comprehensive project in which students have to handle all of them at once. This article will explain a project with students: the virtual reconstruction of the thermal area of the roman villa of Balazote (Albacete. The goal was to improve student motivation and get actively involved in their learning process. Students used computers and classes of the course to conduct such research. First, the necessary information was sought, and then, based on that information and using different software about virtual reconstruction and recording and editing films: Gimp, SketchUP, Movie Maker, etc., our film was made. The result of this work is a film consisting of a virtual tour inside the roman villa.

HEEL BONE RECONSTRUCTIVE OSTEOSYNTHESIS

Directory of Open Access Journals (Sweden)

A. N. Svetashov

2010-01-01

Full Text Available To detect the most appropriate to heel bone injury severity variants of reconstructive osteosynthesis it was analyzed treatment results of 56 patients. In 15 (26.8% patients classic methods of surgical service were applied, in 41 (73.2% cases to restore the defect porous implants were used. Osteosynthesis without heel bone plastic restoration accomplishment was ineffective in 60% patients from control group. Reconstructive osteosynthesis method ensures long-term good functional effect of rehabilitation in 96.4% patients from the basic group.

Comparison of body fat using various bioelectrical impedance analyzers in university students

Directory of Open Access Journals (Sweden)

Petr Kutáč

2015-12-01

Full Text Available Background: At present, the portfolio of devices using the bioelectrical impedance (BIA method is continuously expanding as a result of the wide use of this method in the field as measurements by this method are fast and staff training is simple and reasonably priced. Nonetheless, the problem is that despite using the same method, bioimpedance analyzers can differ in many parameters. They use different electric current frequencies, a different number of electrodes and the electric current may be conducted through different parts of the body.Objective: The main objective of the study is to compare and evaluate the differences of values of the analysis of the body fat of university students measured by BIA analyzers that differ in the applied electric current frequency, number of electrodes and flow of the electric current through the individual body parts.Methods: The research included 125 participants (70 male and 55 female. The measurements were taken by the following analyzers: Tanita 418 MA, InBody 720, InBody R20 and Omron BF 300.Results: The differences in the mean values of the body fat representation between the used analyzers in men ranged from 0.1 to 3.4% and from 0.0 to 2.4 kg, in women from 0.5 to 6.5% and from 0.4 to 3.8 kg in relation to the used analyzer.Conclusions: In men with regular physical activity, the values measured by InBody R20 were statistically and practically different. The analyzer measured higher values that other analyzers. In women, there were statistically and practically significant differences in the values measured by Omron BF 300. This analyzer measured lower values than other analyzers.

Analyzing the Discourse of Dropouts and Resilient Students

Science.gov (United States)

Lessard, Anne; Butler-Kisber, Lynn; Fortin, Laurier; Marcotte, Diane

2014-01-01

The authors focused on high school students who were at risk of dropping out and examined why some of these students persevered and graduated while others ended up dropping out of school. Sixty resilient students and 80 dropouts participated in the study. Our results indicate that although learning difficulties were shared by participants, 4 types…

Analyzing the multiple functions of stereotypical behavior for students with autism: implications for assessment and treatment.

Science.gov (United States)

Kennedy, C H; Meyer, K A; Knowles, T; Shukla, S

2000-01-01

We studied behavioral functions associated with stereotypical responses for students with autism. In Study 1, analogue functional analyses (attention, demand, no-attention, and recreation conditions) were conducted for 5 students. Results suggested that stereotypy was multiply determined or occurred across all assessment conditions. For 2 students, stereotypy was associated with positive and negative reinforcement and the absence of environmental stimulation. For 2 other students, stereotypy occurred at high levels across all experimental conditions. For the 5th student, stereotypy was associated with negative reinforcement and the absence of environmental stimulation. In Study 2, the stereotypy of 1 student was further analyzed on a function-by-function basis. Within a concurrent-schedules procedure, alternative responses were taught to the student using functional communication training. The results of Study 2 showed that similar topographies of stereotypy, based on qualitatively different reinforcers, were reduced only when differential reinforcement contingencies for alternative forms of communication were implemented for specific response-reinforcer relations. Our results suggest that the causes of stereotypy for students with autism are complex and that the presumed association between response topography and behavioral function may be less important than previously realized.

Ways of improving preparatory stage and reconstruction of coking plants

Energy Technology Data Exchange (ETDEWEB)

Rozenfel' d, M.S.; Martynenko, V.M.; Svyatogorov, A.A.; Kvitkin, I.A.; Zhurba, A.I.; Gurtovnik, P.F.

1987-06-01

Discusses economic and technological aspects of coking plant reconstruction and modernization in the USSR. Effects of standardized technologies on plant reconstruction are analyzed. A standardized planning procedure jointly developed by research institutes in the USSR for plant modernization or reconstruction is discussed: selecting the optimum reconstruction and repair time, sequence of operations without stoppage of a coke oven battery, coke oven cooling, repair of coke oven liners, heating systems, coke oven equipment, drying, initial heating, testing battery equipment. The procedure is aimed at reducing coke losses and eliminating delays during reconstruction operations. A graphic method for modelling plant reconstruction is discussed.

Image reconstruction design of industrial CT instrument for teaching

International Nuclear Information System (INIS)

Zou Yongning; Cai Yufang

2009-01-01

Industrial CT instrument for teaching is applied to teaching and study in field of physics and radiology major, image reconstruction is an important part of software on CT instrument. The paper expatiate on CT physical theory and first generation CT reconstruction algorithm, describe scan process of industrial CT instrument for teaching; analyze image artifact as result of displacement of rotation center, implement method of center displacement correcting, design and complete image reconstruction software, application shows that reconstructed image is very clear and qualitatively high. (authors)

Identify and analyze the opportunities and threats of social networks for shahid Beheshti University students

Directory of Open Access Journals (Sweden)

R. Tavalaee

2017-09-01

Full Text Available Due to the growth of information and communication technology in societies Especially among students, the use of these technologies has become as part of regular working people. Social networks as one of the most important and widely in cyberspace which is Used by many people in various fields. application of social network by students as young and educated population is important.In this regard, this study aimed to investigate and identify the opportunities and threats for shahid Beheshti University students in social network. This study aims to develop a practical and descriptive methodology. Information obtained from the questionnaires using SPSS statistical analysis software in two parts: descriptive and inferential statistics were analyzed.The results indicate that five variables related to social networking opportunities, including e-learning, leisure, organized social groups, the possibility of dialogue and culture, as well as five variables related to social networking threats, including transfer value unethical, abusive, spreading false information, internet & Communications destructive addiction, has a significant positive effect on students.

Failed medial patellofemoral ligament reconstruction: Causes and surgical strategies

OpenAIRE

Sanchis-Alfonso, Vicente; Montesinos-Berry, Erik; Ramirez-Fuentes, Cristina; Leal Blanquet, Joan; Gelber, Pablo-Eduardo; Monllau García, Juan Carlos

2017-01-01

Patellar instability is a common clinical problem encountered by orthopedic surgeons specializing in the knee. For patients with chronic lateral patellar instability, the standard surgical approach is to stabilize the patella through a medial patellofemoral ligament (MPFL) reconstruction. Foreseeably, an increasing number of revision surgeries of the reconstructed MPFL will be seen in upcoming years. In this paper, the causes of failed MPFL reconstruction are analyzed: (1) incorrect surgical ...

Analyzing High School Students' Reasoning about Electromagnetic Induction

Science.gov (United States)

Jelicic, Katarina; Planinic, Maja; Planinsic, Gorazd

2017-01-01

Electromagnetic induction is an important, yet complex, physics topic that is a part of Croatian high school curriculum. Nine Croatian high school students of different abilities in physics were interviewed using six demonstration experiments from electromagnetism (three of them concerned the topic of electromagnetic induction). Students were…

From biology to mathematical models and back: teaching modeling to biology students, and biology to math and engineering students.

Science.gov (United States)

Chiel, Hillel J; McManus, Jeffrey M; Shaw, Kendrick M

2010-01-01

We describe the development of a course to teach modeling and mathematical analysis skills to students of biology and to teach biology to students with strong backgrounds in mathematics, physics, or engineering. The two groups of students have different ways of learning material and often have strong negative feelings toward the area of knowledge that they find difficult. To give students a sense of mastery in each area, several complementary approaches are used in the course: 1) a "live" textbook that allows students to explore models and mathematical processes interactively; 2) benchmark problems providing key skills on which students make continuous progress; 3) assignment of students to teams of two throughout the semester; 4) regular one-on-one interactions with instructors throughout the semester; and 5) a term project in which students reconstruct, analyze, extend, and then write in detail about a recently published biological model. Based on student evaluations and comments, an attitude survey, and the quality of the students' term papers, the course has significantly increased the ability and willingness of biology students to use mathematical concepts and modeling tools to understand biological systems, and it has significantly enhanced engineering students' appreciation of biology.

From Biology to Mathematical Models and Back: Teaching Modeling to Biology Students, and Biology to Math and Engineering Students

Science.gov (United States)

McManus, Jeffrey M.; Shaw, Kendrick M.

2010-01-01

We describe the development of a course to teach modeling and mathematical analysis skills to students of biology and to teach biology to students with strong backgrounds in mathematics, physics, or engineering. The two groups of students have different ways of learning material and often have strong negative feelings toward the area of knowledge that they find difficult. To give students a sense of mastery in each area, several complementary approaches are used in the course: 1) a “live” textbook that allows students to explore models and mathematical processes interactively; 2) benchmark problems providing key skills on which students make continuous progress; 3) assignment of students to teams of two throughout the semester; 4) regular one-on-one interactions with instructors throughout the semester; and 5) a term project in which students reconstruct, analyze, extend, and then write in detail about a recently published biological model. Based on student evaluations and comments, an attitude survey, and the quality of the students' term papers, the course has significantly increased the ability and willingness of biology students to use mathematical concepts and modeling tools to understand biological systems, and it has significantly enhanced engineering students' appreciation of biology. PMID:20810957

Analyzing historical land use changes using a Historical Land Use Reconstruction Model: a case study in Zhenlai County, northeastern China

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Yang, Yuanyuan; Zhang, Shuwen; Liu, Yansui; Xing, Xiaoshi; de Sherbinin, Alex

2017-01-01

Historical land use information is essential to understanding the impact of anthropogenic modification of land use/cover on the temporal dynamics of environmental and ecological issues. However, due to a lack of spatial explicitness, complete thematic details and the conversion types for historical land use changes, the majority of historical land use reconstructions do not sufficiently meet the requirements for an adequate model. Considering these shortcomings, we explored the possibility of constructing a spatially-explicit modeling framework (HLURM: Historical Land Use Reconstruction Model). Then a three-map comparison method was adopted to validate the projected reconstruction map. The reconstruction suggested that the HLURM model performed well in the spatial reconstruction of various land-use categories, and had a higher figure of merit (48.19%) than models used in other case studies. The largest land use/cover type in the study area was determined to be grassland, followed by arable land and wetland. Using the three-map comparison, we noticed that the major discrepancies in land use changes among the three maps were as a result of inconsistencies in the classification of land-use categories during the study period, rather than as a result of the simulation model. PMID:28134342

Maxillary reconstruction: Current concepts and controversies

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Subramania Iyer

2014-01-01

Full Text Available Maxillary reconstruction is still an evolving art when compared to the reconstruction of the mandible. The defects of maxilla apart from affecting the functions of the speech, swallowing and mastication also cause cosmetic disfigurement. Rehabilitation of the form and function in patients with maxillary defects is either by using an obturator prosthesis or by a surgical reconstruction. Literature is abundant with a variety of reconstructive methods. The classification systems are also varied, with no universal acceptance of any one of them. The oncologic safety of these procedures is still debated, and conclusive evidence in this regard has not emerged yet. Management of the orbit is also not yet addressed properly. Tissue engineering, that has been hyped to be one of the possible solutions for this vexing reconstructive problem, has not come out with reliable and reproducible results so far. This review article discusses the rationale and oncological safety of the reconstructing the maxillary defects, critically analyzes the classification systems, offers the different reconstructive methods and touches upon the controversies in this subject. The management of the retained and exenterated orbit associated with maxillectomy is reviewed. The surgical morbidity, complications and the recent advances in this field are also looked into. An algorithm, based on our experience, is presented.

Maxillary reconstruction: Current concepts and controversies

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Iyer, Subramania; Thankappan, Krishnakumar

2014-01-01

Maxillary reconstruction is still an evolving art when compared to the reconstruction of the mandible. The defects of maxilla apart from affecting the functions of the speech, swallowing and mastication also cause cosmetic disfigurement. Rehabilitation of the form and function in patients with maxillary defects is either by using an obturator prosthesis or by a surgical reconstruction. Literature is abundant with a variety of reconstructive methods. The classification systems are also varied, with no universal acceptance of any one of them. The oncologic safety of these procedures is still debated, and conclusive evidence in this regard has not emerged yet. Management of the orbit is also not yet addressed properly. Tissue engineering, that has been hyped to be one of the possible solutions for this vexing reconstructive problem, has not come out with reliable and reproducible results so far. This review article discusses the rationale and oncological safety of the reconstructing the maxillary defects, critically analyzes the classification systems, offers the different reconstructive methods and touches upon the controversies in this subject. The management of the retained and exenterated orbit associated with maxillectomy is reviewed. The surgical morbidity, complications and the recent advances in this field are also looked into. An algorithm, based on our experience, is presented. PMID:24987199

Against the Standards: Analyzing Expectations and Discourse of Educators regarding Students with Disabilities in a Kindergarten Classroom

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Fernanda T. Orsati

2014-01-01

Full Text Available This two-year ethnographic case study critically examines the language educators use to describe students with disabilities who are considered to present challenging behaviors in one classroom. Focusing on the language and practices used by one special education teacher and three teaching assistants, this paper explores how educators respond to students’ behaviors by analyzing educators’ utterances and the implication of such use for the education of the students. Using critical discourse analysis, this paper highlights how educators’ language in the classroom reflects a discourse of expectations that is based on various social standards and pressures that educators have to juggle. Educators expressed academic and behavioral standards by comparing students’ performance to the expected norm as well as through comparisons between students. Based on such comparisons, some students were constructed as always lacking and ultimately defined by the adjectives originally used to describe them. Students were perceived to embody defiance or smartness, the characteristics by which they were defined.

Rethinking library service to distance education students: analyzing the embedded librarian model.

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Sullo, Elaine; Harrod, Tom; Butera, Gisela; Gomes, Alexandra

2012-01-01

Since fall 2009, reference librarians at The George Washington University's Himmelfarb Health Sciences Library have been embedded in online classes through Blackboard within the School of Nursing and School of Medicine and Health Sciences. The authors sought to determine the types of questions asked of the librarian, with the goal of informing future interactions with distance education classes to help develop a standard "protocol" for working with this population of students. Eighty-two questions were categorized and qualitatively analyzed. The findings have prompted librarians to explore tools such as Elluminate Live!, a tool that allows librarians to provide synchronous instruction within the Blackboard environment. Copyright © Taylor & Francis Group, LLC

Research on compressive sensing reconstruction algorithm based on total variation model

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Gao, Yu-xuan; Sun, Huayan; Zhang, Tinghua; Du, Lin

2017-12-01

Compressed sensing for breakthrough Nyquist sampling theorem provides a strong theoretical , making compressive sampling for image signals be carried out simultaneously. In traditional imaging procedures using compressed sensing theory, not only can it reduces the storage space, but also can reduce the demand for detector resolution greatly. Using the sparsity of image signal, by solving the mathematical model of inverse reconfiguration, realize the super-resolution imaging. Reconstruction algorithm is the most critical part of compression perception, to a large extent determine the accuracy of the reconstruction of the image.The reconstruction algorithm based on the total variation (TV) model is more suitable for the compression reconstruction of the two-dimensional image, and the better edge information can be obtained. In order to verify the performance of the algorithm, Simulation Analysis the reconstruction result in different coding mode of the reconstruction algorithm based on the TV reconstruction algorithm. The reconstruction effect of the reconfigurable algorithm based on TV based on the different coding methods is analyzed to verify the stability of the algorithm. This paper compares and analyzes the typical reconstruction algorithm in the same coding mode. On the basis of the minimum total variation algorithm, the Augmented Lagrangian function term is added and the optimal value is solved by the alternating direction method.Experimental results show that the reconstruction algorithm is compared with the traditional classical algorithm based on TV has great advantages, under the low measurement rate can be quickly and accurately recovers target image.

Beard reconstruction: A surgical algorithm.

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Ninkovic, M; Heidekrueger, P I; Ehrl, D; von Spiegel, F; Broer, P N

2016-06-01

Facial defects with loss of hair-bearing regions can be caused by trauma, infection, tumor excision, or burn injury. The presented analysis evaluates a series of different surgical approaches with a focus on male beard reconstruction, emphasizing the role of tissue expansion of regional and free flaps. Locoregional and free flap reconstructions were performed in 11 male patients with 14 facial defects affecting the hair-bearing bucco-mandibular or perioral region. In order to minimize donor-site morbidity and obtain large amounts of thin, pliable, hair-bearing tissue, pre-expansion was performed in five of 14 patients. Eight of 14 patients were treated with locoregional flap reconstructions and six with free flap reconstructions. Algorithms regarding pre- and intraoperative decision making are discussed and long-term (mean follow-up 1.5 years) results analyzed. Major complications, including tissue expander infection with the need for removal or exchange, partial or full flap loss, occurred in 0% (0/8) of patients with locoregional flaps and in 17% (1/6) of patients undergoing free flap reconstructions. Secondary refinement surgery was performed in 25% (2/8) of locoregional flaps and in 67% (4/6) of free flaps. Both locoregional and distant tissue transfers play a role in beard reconstruction, while pre-expansion remains an invaluable tool. Paying attention to the presented principles and considering the significance of aesthetic facial subunits, range of motion, aesthetics, and patient satisfaction were improved long term in all our patients while minimizing donor-site morbidity. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Analyzing Ocean Tracks: A model for student engagement in authentic scientific practices using data

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Krumhansl, K.; Krumhansl, R.; Brown, C.; DeLisi, J.; Kochevar, R.; Sickler, J.; Busey, A.; Mueller-Northcott, J.; Block, B.

2013-12-01

The collection of large quantities of scientific data has not only transformed science, but holds the potential to transform teaching and learning by engaging students in authentic scientific work. Furthermore, it has become imperative in a data-rich world that students gain competency in working with and interpreting data. The Next Generation Science Standards reflect both the opportunity and need for greater integration of data in science education, and emphasize that both scientific knowledge and practice are essential elements of science learning. The process of enabling access by novice learners to data collected and used by experts poses significant challenges, however, recent research has demonstrated that barriers to student learning with data can be overcome by the careful design of data access and analysis tools that are specifically tailored to students. A group of educators at Education Development Center, Inc. (EDC) and scientists at Stanford University's Hopkins Marine Station are collaborating to develop and test a model for student engagement with scientific data using a web-based platform. This model, called Ocean Tracks: Investigating Marine Migrations in a Changing Ocean, provides students with the ability to plot and analyze tracks of migrating marine animals collected through the Tagging of Pacific Predators program. The interface and associated curriculum support students in identifying relationships between animal behavior and physical oceanographic variables (e.g. SST, chlorophyll, currents), making linkages between the living world and climate. Students are also supported in investigating possible sources of human impact to important biodiversity hotspots in the Pacific Ocean. The first round of classroom testing revealed that students were able to easily access and display data on the interface, and collect measurements from the animal tracks and oceanographic data layers. They were able to link multiple types of data to draw powerful

Instrument Variables for Reducing Noise in Parallel MRI Reconstruction

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Yuchou Chang

2017-01-01

Full Text Available Generalized autocalibrating partially parallel acquisition (GRAPPA has been a widely used parallel MRI technique. However, noise deteriorates the reconstructed image when reduction factor increases or even at low reduction factor for some noisy datasets. Noise, initially generated from scanner, propagates noise-related errors during fitting and interpolation procedures of GRAPPA to distort the final reconstructed image quality. The basic idea we proposed to improve GRAPPA is to remove noise from a system identification perspective. In this paper, we first analyze the GRAPPA noise problem from a noisy input-output system perspective; then, a new framework based on errors-in-variables (EIV model is developed for analyzing noise generation mechanism in GRAPPA and designing a concrete method—instrument variables (IV GRAPPA to remove noise. The proposed EIV framework provides possibilities that noiseless GRAPPA reconstruction could be achieved by existing methods that solve EIV problem other than IV method. Experimental results show that the proposed reconstruction algorithm can better remove the noise compared to the conventional GRAPPA, as validated with both of phantom and in vivo brain data.

Porous media microstructure reconstruction using pixel-based and object-based simulated annealing: comparison with other reconstruction methods

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Diogenes, Alysson N.; Santos, Luis O.E. dos; Fernandes, Celso P. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil); Appoloni, Carlos R. [Universidade Estadual de Londrina (UEL), PR (Brazil)

2008-07-01

The reservoir rocks physical properties are usually obtained in laboratory, through standard experiments. These experiments are often very expensive and time-consuming. Hence, the digital image analysis techniques are a very fast and low cost methodology for physical properties prediction, knowing only geometrical parameters measured from the rock microstructure thin sections. This research analyzes two methods for porous media reconstruction using the relaxation method simulated annealing. Using geometrical parameters measured from rock thin sections, it is possible to construct a three-dimensional (3D) model of the microstructure. We assume statistical homogeneity and isotropy and the 3D model maintains porosity spatial correlation, chord size distribution and d 3-4 distance transform distribution for a pixel-based reconstruction and spatial correlation for an object-based reconstruction. The 2D and 3D preliminary results are compared with microstructures reconstructed by truncated Gaussian methods. As this research is in its beginning, only the 2D results will be presented. (author)

THE CHALLENGE OF KEEPING-UP: CURRENT METHODOLOGIES IN ANALYZING THE STUDENTS RECRUITING AREA BY UNIVERSITIES

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MĂLĂESCU SIMONA

2013-11-01

Full Text Available The challenge of keeping-up: current methodologies in analyzing the students recruiting area by universities. Despite all progress made in the field and in some collateral areas extremely useful methodologically (e.g. the use of GIS, for some countries emerging from communist space methodologically upgrading to the latest advances in modelling and forecast of students recruitment by universities remains a difficult challenge. The analysis and modelling of the geographical area of recruiting students for a particular university represents even for the foreign literature a niche, not necessarily consciously neglected but only reached sidely due, most likely, to ignoring the benefits which the focus of concerns on this aspect would bring into focus and directing more efficiently university marketing efforts. This paper aims precisely to seek, through a meta-analysis of existing literature, disparate developments that led in some form or will allow improved modeling spatial areas of recruitment of students by universities and the challenges and limitations that apply methodological advances the area where universities belonging to the ex-communist involved. Beyond the theoretical benefit from a practical perspective, the meta-analysis aimed at synthesizing elements of good practice that can be applied to the local university system.

Learners' strategies for reconstructing cognitive frameworks and navigating conceptual change from prior conception to consensual genetics knowledge

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Parrott, Annette M.

Problem. Science teachers are charged with preparing students to become scientifically literate individuals. Teachers are given curriculum that specifies the knowledge that students should come away with; however, they are not necessarily aware of the knowledge with which the student arrives or how best to help them navigate between the two knowledge states. Educators must be aware, not only of where their students are conceptually, but how their students move from their prior knowledge and naive theories, to scientifically acceptable theories. The understanding of how students navigate this course has the potential to revolutionize educational practices. Methods. This study explored how five 9th grade biology students reconstructed their cognitive frameworks and navigated conceptual change from prior conception to consensual genetics knowledge. The research questions investigated were: (1) how do students in the process of changing their naive science theories to accepted science theories describe their journey from prior knowledge to current conception, and (2) what are the methods that students utilize to bridge the gap between alternate and consensual science conceptions to effect conceptual change. Qualitative and quantitative methods were employed to gather and analyze the data. In depth, semi-structured interviews formed the primary data for probing the context and details of students' conceptual change experience. Primary interview data was coded by thematic analysis. Results and discussion. This study revealed information about students' perceived roles in learning, the role of articulation in the conceptual change process, and ways in which a community of learners aids conceptual change. It was ascertained that students see their role in learning primarily as repeating information until they could add that information to their knowledge. Students are more likely to consider challenges to their conceptual frameworks and be more motivated to become active

Sensation Following Immediate Breast Reconstruction with Implants.

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Lagergren, Jakob; Wickman, Marie; Hansson, Per

2010-01-01

Sensation is a neglected aspect of the outcome of breast reconstructions with implants. The aim of this prospective study was to evaluate the cutaneous somatosensory status in breasts following mastectomy and immediate reconstruction with permanent adjustable prostheses and to analyze the patients' subjective experience of the sensation. Twenty-four consecutive patients diagnosed with invasive or in situ breast carcinoma were examined preoperatively and 2 years after mastectomy and reconstruction, for assessment of perception thresholds for touch, cold, warmth, and heat pain above and below the areola. Von Frey filaments and a Peltier element-based thermode were used. The patients completed a questionnaire concerning their experienced sensation in the reconstructed breast. Using quantitative somato-sensory testing, the sensation to all the examined modalities was significantly impaired compared to preoperatively. Most affected was the area above the areola. Patients given postoperative radiotherapy (n = 9) did not differ from those without radiotherapy (n = 15) regarding any of the modalities. All patients reported reduced sensation in the reconstructed breast compared to that preoperatively. Twenty-three patients stated that the reconstructed breast felt different from the other breast; nevertheless 16 reported that the reconstructed breast felt like a real breast. The study revealed sensation impairment following mastectomy and immediate reconstruction with implants. Patients should be informed about this effect preoperatively to allow adequate expectations regarding the sensation outcome. However, two-thirds of the study patients considered that the reconstructed breast felt like a real breast, which must be one of the main purposes of a breast reconstruction.

A Method for Using Adjacency Matrices to Analyze the Connections Students Make within and between Concepts: The Case of Linear Algebra

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Selinski, Natalie E.; Rasmussen, Chris; Wawro, Megan; Zandieh, Michelle

2014-01-01

The central goals of most introductory linear algebra courses are to develop students' proficiency with matrix techniques, to promote their understanding of key concepts, and to increase their ability to make connections between concepts. In this article, we present an innovative method using adjacency matrices to analyze students' interpretation…

The sky is the limit: reconstructing physical geography fieldwork from an aerial perspective

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Williams, R.; Tooth, S.; Gibson, M.; Barrett, B.

2017-12-01

In an era of rapid geographical data acquisition, interpretations of remote sensing products (e.g. aerial photographs, satellite images, digital elevation models) are an integral part of many undergraduate geography degree schemes but there are fewer opportunities for collection and processing of primary remote sensing data. Unmanned aerial vehicles (UAVs) provide a relatively cheap opportunity to introduce the principles and practice of airborne remote sensing into fieldcourses, enabling students to learn about image acquisition, data processing and interpretation of derived products. Three case studies illustrate how a low cost DJI Phantom UAV can be used by students to acquire images that can be processed using off the shelf Structure-from-Motion photogrammetry software. Two case studies are drawn from an international fieldcourse that takes students to field sites that are the focus of current funded research whilst a third case study is from a course in topographic mapping. Results from a student questionnaire and analysis of assessed student reports showed that using UAVs in fieldwork enhanced student engagement with themes on their fieldcourse and equipped them with data processing skills. The derivation of bespoke orthophotos and Digital Elevation Models also provided students with opportunities to gain insight into the various data quality issues that are associated with aerial imagery acquisition and topographic reconstruction, although additional training is required to maximise this potential. Recognition of the successes and limitations of this teaching intervention provides scope for improving exercises that use UAVs and other technologies in future fieldcourses. UAVs are enabling both a reconstruction of how we measure the Earth's surface and a reconstruction of how students do fieldwork.

[Reconstructive surgery of cranio-orbital injuries].

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Eolchiian, S A; Potapov, A A; Serova, N K; Kataev, M G; Sergeeva, L A; Zakharova, N E; Van Damm, P

2011-01-01

The aim of study was to optimize evaluation and surgery of cranioorbital injuries in different periods after trauma. Material and methods. We analyzed 374 patients with cranioorbital injuries treated in Burdenko Neurosurgery Institute in different periods after trauma from January 1998 till April 2010. 288 (77%) underwent skull and facial skeleton reconstructive surgery within 24 hours - 7 years after trauma. Clinical and CT examination data were used for preoperative planning and assessment of surgery results. Stereolithographic models (STLM) were applied for preoperative planning in 89 cases. The follow-up period ranged from 4 months up to 10 years. Results. In 254 (88%) of 288 patients reconstruction of anterior skull base, upper and/or midface with restoration of different parts of orbit was performed. Anterior skull base CSF leaks repair, calvarial vault reconstruction, maxillar and mandibular osteosynthesis were done in 34 (12%) cases. 242 (84%) of 288 patients underwent one reconstructive operation, while 46 (16%)--two and more (totally 105 operations). The patients with extended frontoorbital and midface fractures commonly needed more than one operation--in 27 (62.8%) cases. Different plastic materials were used for reconstruction in 233 (80.9%) patients, of those in 147 (51%) cases split calvarial bone grafts were preferred. Good functional and cosmetic results were achieved in 261 (90.6%) of 288 patients while acceptable were observed in 27 (9.4%). Conclusion. Active single-stage surgical management for repair of combined cranioorbital injury in acute period with primary reconstruction optimizes functional and cosmetic outcomes and prevents the problems of delayed or secondary reconstruction. Severe extended anterior skull base, upper and midface injuries when intracranial surgery is needed produced the most challenging difficulties for adequate reconstruction. Randomized trial is required to define the extent and optimal timing of reconstructive surgery

NASAL-Geom, a free upper respiratory tract 3D model reconstruction software

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Cercos-Pita, J. L.; Cal, I. R.; Duque, D.; de Moreta, G. Sanjuán

2018-02-01

The tool NASAL-Geom, a free upper respiratory tract 3D model reconstruction software, is here described. As a free software, researchers and professionals are welcome to obtain, analyze, improve and redistribute it, potentially increasing the rate of development, and reducing at the same time ethical conflicts regarding medical applications which cannot be analyzed. Additionally, the tool has been optimized for the specific task of reading upper respiratory tract Computerized Tomography scans, and producing 3D geometries. The reconstruction process is divided into three stages: preprocessing (including Metal Artifact Reduction, noise removal, and feature enhancement), segmentation (where the nasal cavity is identified), and 3D geometry reconstruction. The tool has been automatized (i.e. no human intervention is required) a critical feature to avoid bias in the reconstructed geometries. The applied methodology is discussed, as well as the program robustness and precision.

Using the UTAUT Model to Analyze Students' ICT Adoption

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Attuquayefio, Samuel NiiBoi; Addo, Hillar

2014-01-01

This paper seeks to provide further understanding of issues surrounding acceptance of information and communication technology (ICT) by students of tertiary institutions. The Unified Theory of Acceptance and Use of Technology (UTAUT) model Venkatesh et al (2003) was employed by the researchers to determine the strength of predictors for students'…

Complications in Postmastectomy Breast Reconstruction: One-year Outcomes of the Mastectomy Reconstruction Outcomes Consortium (MROC) Study.

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Wilkins, Edwin G; Hamill, Jennifer B; Kim, Hyungjin M; Kim, John Y; Greco, Richard J; Qi, Ji; Pusic, Andrea L

2018-01-01

In postmastectomy reconstruction, procedure choice is heavily influenced by the relative risks of the various options. This study sought to evaluate complications in a large, multicenter patient population. Previous studies have reported widely varying complication rates, but have been limited by their single center designs and inadequate controlling for confounders in their analyses. Eleven sites enrolled women undergoing first time, immediate, or delayed reconstruction following mastectomy for cancer treatment or prophylaxis. Procedures included expander/implant, latissimus dorsi (LD), pedicle transverse rectus abdominis musculocutaneous (PTRAM), free TRAM (FTRAM), and deep inferior epigastric perforator (DIEP) techniques. Data were gathered pre- and postoperatively from medical records. Separate logistic regressions were conducted for all complications and major complications (those requiring rehospitalization and/or reoperation) within 1 year. Odds ratios (ORs) were calculated for procedure type, controlling for site, demographic, and clinical variables. Complication rates for 2234 patients were analyzed. Compared with expander/implant reconstructions, LD (OR) 1.95, P = 0.026), PTRAM (OR 1.89, P = 0.025), FTRAM (OR 1.94, P = 0.011), and DIEP (OR 2.22, P procedures were associated with higher risks of complications. Significantly higher risks were also associated with older age, higher body mass index (BMI), immediate reconstruction, bilateral procedures, and radiation. For major complications, regression showed significantly greater risks for PTRAM (OR 1.86, P = 0.044) and DIEP (OR 1.75, P = 0.004), than expander/implant reconstructions. Failure rates were relatively low, ranging from 0% for PTRAM to 5.9% for expander/implant reconstructions. In this multicenter analysis, procedure choice and other patient variables were significant predictors of 1-year complications in breast reconstruction. These findings should be considered in counseling patients on

ANALYZING THE MATHEMATICAL DISPOSITION AND ITS CORRELATION WITH MATHEMATICS ACHIEVEMENT OF ABSTRACT SENIOR HIGH SCHOOL STUDENTS

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Louise M. Saija

2012-09-01

Full Text Available Salah satu standar yang diberikan oleh National Council of Teachers of Mathematics (NCTM adalah disposisi matematik. Disposisi  bukan sekedar merujuk pada sikap tetapi suatu kecenderungan untuk berpikir dan bersikap dalam cara yang positif. Penelitian ini bertujuan untuk menganalisa disposisi matematik dan hubungannya dengan hasil belajar matematika siswa-siswa sekolah menengah atas (SMA. Sampel pada penelitian ini adalah 149 siswa SMA di Bandung. Analisa statistik didasarkan pada korelasi peringkat Spearman dan uji-t. Ditemukan bahwa secara rata-rata,  disposisi matematik dari siswa-siswa SMA dikategorikan rendah. Selanjutnya, terdapat korelasi positif dan signifikan antara disposisi matematik dan hasil belajar matematika siswa-siswa SMA, walaupun nilai koefisien korelasinya tidak tinggi. Suatu observasi juga dilakukan untuk menganalisa hubungan ini, dan didapati bahwa walaupun beberapa siswa memiliki disposisi matematik yang baik, kadang kala mereka tidak dapat menyelesaikan ujian dengan baik, karena padatnya kurikulum, dan juga aktifitas sosial mereka, yang membuat hasil belajar matematika mereka lebih rendah. Temuan lainnya adalah bahwa siswa-siswa SMA memerlukan guru-guru matematika dengan lebih banyak strategi mengajar  agar mereka dapat memiliki disposisi matematik yang lebih baik.   Kata Kunci: Disposisi Matematik, Hasil Belajar Matematika       One of the evaluation standards given by the National Council of Teachers of Mathematics (NCTM was mathematical disposition. Disposition refers not simply to attitudes but to a tendency to think and to act in positive ways. This study aimed to analyze the mathematical disposition and its correlation with mathematics achievement of senior high school (SMA students. A total of 149 SMA students in Bandung were procured as samples. Statistical analysis was based on the Spearman rank correlation and on the t-test. The findings showed that at average, the mathematical disposition of the SMA

Photoelectron holography with improved image reconstruction

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Matsushita, Tomohiro, E-mail: matusita@spring8.or.j [Japan Synchrotron Radiation Research Institute (JASRI), SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun Hyogo 679-5198 (Japan); Matsui, Fumihiko; Daimon, Hiroshi [Nara Institute of Science and Technology (NAIST), 8916-5 Takayama, Ikoma, Nara 630-0192 (Japan); Hayashi, Kouichi [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

2010-05-15

Electron holography is a type of atomic structural analysis, and it has unique features such as element selectivity and the ability to analyze the structure around an impurity in a crystal. In this paper, we introduce the measurement system, electron holograms, a theory for the recording process of an electron hologram, and a theory for the reconstruction algorithm. We describe photoelectron holograms, Auger electron holograms, and the inverse mode of an electron hologram. The reconstruction algorithm, scattering pattern extraction algorithm (SPEA), the SPEA with maximum entropy method (SPEA-MEM), and SPEA-MEM with translational operation are also described.

Photoelectron holography with improved image reconstruction

International Nuclear Information System (INIS)

Matsushita, Tomohiro; Matsui, Fumihiko; Daimon, Hiroshi; Hayashi, Kouichi

2010-01-01

Electron holography is a type of atomic structural analysis, and it has unique features such as element selectivity and the ability to analyze the structure around an impurity in a crystal. In this paper, we introduce the measurement system, electron holograms, a theory for the recording process of an electron hologram, and a theory for the reconstruction algorithm. We describe photoelectron holograms, Auger electron holograms, and the inverse mode of an electron hologram. The reconstruction algorithm, scattering pattern extraction algorithm (SPEA), the SPEA with maximum entropy method (SPEA-MEM), and SPEA-MEM with translational operation are also described.

Accelerated Compressed Sensing Based CT Image Reconstruction.

Science.gov (United States)

Hashemi, SayedMasoud; Beheshti, Soosan; Gill, Patrick R; Paul, Narinder S; Cobbold, Richard S C

2015-01-01

In X-ray computed tomography (CT) an important objective is to reduce the radiation dose without significantly degrading the image quality. Compressed sensing (CS) enables the radiation dose to be reduced by producing diagnostic images from a limited number of projections. However, conventional CS-based algorithms are computationally intensive and time-consuming. We propose a new algorithm that accelerates the CS-based reconstruction by using a fast pseudopolar Fourier based Radon transform and rebinning the diverging fan beams to parallel beams. The reconstruction process is analyzed using a maximum-a-posterior approach, which is transformed into a weighted CS problem. The weights involved in the proposed model are calculated based on the statistical characteristics of the reconstruction process, which is formulated in terms of the measurement noise and rebinning interpolation error. Therefore, the proposed method not only accelerates the reconstruction, but also removes the rebinning and interpolation errors. Simulation results are shown for phantoms and a patient. For example, a 512 × 512 Shepp-Logan phantom when reconstructed from 128 rebinned projections using a conventional CS method had 10% error, whereas with the proposed method the reconstruction error was less than 1%. Moreover, computation times of less than 30 sec were obtained using a standard desktop computer without numerical optimization.

Accelerated Compressed Sensing Based CT Image Reconstruction

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SayedMasoud Hashemi

2015-01-01

Full Text Available In X-ray computed tomography (CT an important objective is to reduce the radiation dose without significantly degrading the image quality. Compressed sensing (CS enables the radiation dose to be reduced by producing diagnostic images from a limited number of projections. However, conventional CS-based algorithms are computationally intensive and time-consuming. We propose a new algorithm that accelerates the CS-based reconstruction by using a fast pseudopolar Fourier based Radon transform and rebinning the diverging fan beams to parallel beams. The reconstruction process is analyzed using a maximum-a-posterior approach, which is transformed into a weighted CS problem. The weights involved in the proposed model are calculated based on the statistical characteristics of the reconstruction process, which is formulated in terms of the measurement noise and rebinning interpolation error. Therefore, the proposed method not only accelerates the reconstruction, but also removes the rebinning and interpolation errors. Simulation results are shown for phantoms and a patient. For example, a 512 × 512 Shepp-Logan phantom when reconstructed from 128 rebinned projections using a conventional CS method had 10% error, whereas with the proposed method the reconstruction error was less than 1%. Moreover, computation times of less than 30 sec were obtained using a standard desktop computer without numerical optimization.

Digital reconstruction of Young's fringes using Fresnel transformation

Science.gov (United States)

Kulenovic, Rudi; Song, Yaozu; Renninger, P.; Groll, Manfred

1997-11-01

This paper deals with the digital numerical reconstruction of Young's fringes from laser speckle photography by means of the Fresnel-transformation. The physical model of the optical reconstruction of a specklegram is a near-field Fresnel-diffraction phenomenon which can be mathematically described by the Fresnel-transformation. Therefore, the interference phenomena can be directly calculated by a microcomputer.If additional a CCD-camera is used for specklegram recording the measurement procedure and evaluation process can be completely carried out in a digital way. Compared with conventional laser speckle photography no holographic plates, no wet development process and no optical specklegram reconstruction are needed. These advantages reveal a wide future in scientific and engineering applications. The basic principle of the numerical reconstruction is described, the effects of experimental parameters of Young's fringes are analyzed and representative results are presented.

[Clinical application of combined hepatic artery resection and reconstruction in surgical treatment for hilar cholangiocarcinoma].

Science.gov (United States)

Dai, H S; Bie, P; Wang, S G; He, Y; Li, D J; Tian, F; Zhao, X; Chen, Z Y

2018-01-01

Objective: To clarify whether the surgical treatment for hilar cholangiocarcinoma combined with artery reconstruction is optimistic to the patients with hilar cholangiocarcinoma with hepatic artery invasion. Methods: There were 384 patients who received treatment in the First Affiliated Hospital to Army Medical University from January 2008 to January 2016 analyzed retrospectively. There were 27 patients underwent palliative operation, 245 patients underwent radical operation, radical resection account for 63.8%. Patients were divided into four groups according to different operation method: routine radical resection group( n =174), portal vein reconstruction group ( n =47), hepatic artery reconstruction group ( n =24), palliative group( n =27). General information of patients who underwent radical operation treatment was analyzed by chi-square test and analysis of variance. The period of operation time, blood loss, the length of hospital stay and hospitalization expenses of the radical operation patients were analyzed by one-way ANOVA. Comparison among groups was analyzed by LSD- t test. Results: The follow-up ended up in June first, 2016. Each of patients followed for 6 to 60 months, the median follow-up period was 24 months. 1-, 3-, and 5-year survival rates were 81.3%, 44.9% and 13.5% of routine radical operation group, and were 83.0%, 44.7% and 15.1% of portal vein reconstruction group, and were 70.8%, 27.7% and 6.9% of hepatic artery reconstruction group, respectively. And 1-, 3-, and 5-year survival rates of hepatic artery reconstruction group was lower than routine radical group and portal vein reconstruction group significantly ( P 0.05). The data shows that the ratio of lymphatic metastasis in hepatic artery reconstruction group (70.8%) is much higher than them in routine radical operation group (20.1%) and portal vein reconstruction group (19.1%) significantly ( P hilar cholangiocarcinoma. Cox regression analysis indicate that hepatic artery resection and

Does Burnout Begin with Student-Teaching? Analyzing Efficacy, Burnout, and Support during the Student-Teaching Semester

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Fives, Helenrose; Hamman, Doug; Olivarez, Arturo

2007-01-01

The burnout process may begin as early as the student-teaching experience [Gold, Y., 1985. Does teacher burnout begin with student teaching? "Education", 105, 254-257]. Data from 49 student-teachers in the southwest United States were gathered twice during their student-teaching practicum. Data assessing teacher efficacy, teacher…

Earth Exploration Toolbook Workshops: Helping Teachers and Students Analyze Web-based Scientific Data

Science.gov (United States)

McAuliffe, C.; Ledley, T.; Dahlman, L.; Haddad, N.

2007-12-01

One of the challenges faced by Earth science teachers, particularly in K-12 settings, is that of connecting scientific research to classroom experiences. Helping teachers and students analyze Web-based scientific data is one way to bring scientific research to the classroom. The Earth Exploration Toolbook (EET) was developed as an online resource to accomplish precisely that. The EET consists of chapters containing step-by-step instructions for accessing Web-based scientific data and for using a software analysis tool to explore issues or concepts in science, technology, and mathematics. For example, in one EET chapter, users download Earthquake data from the USGS and bring it into a geographic information system (GIS), analyzing factors affecting the distribution of earthquakes. The goal of the EET Workshops project is to provide professional development that enables teachers to incorporate Web-based scientific data and analysis tools in ways that meet their curricular needs. In the EET Workshops project, Earth science teachers participate in a pair of workshops that are conducted in a combined teleconference and Web-conference format. In the first workshop, the EET Data Analysis Workshop, participants are introduced to the National Science Digital Library (NSDL) and the Digital Library for Earth System Education (DLESE). They also walk through an Earth Exploration Toolbook (EET) chapter and discuss ways to use Earth science datasets and tools with their students. In a follow-up second workshop, the EET Implementation Workshop, teachers share how they used these materials in the classroom by describing the projects and activities that they carried out with students. The EET Workshops project offers unique and effective professional development. Participants work at their own Internet-connected computers, and dial into a toll-free group teleconference for step-by-step facilitation and interaction. They also receive support via Elluminate, a Web

Automated track recognition and event reconstruction in nuclear emulsion

International Nuclear Information System (INIS)

Deines-Jones, P.; Aranas, A.; Cherry, M.L.; Dugas, J.; Kudzia, D.; Nilsen, B.S.; Sengupta, K.; Waddington, C.J.; Wefel, J.P.; Wilczynska, B.; Wilczynski, H.; Wosiek, B.

1997-01-01

The major advantages of nuclear emulsion for detecting charged particles are its submicron position resolution and sensitivity to minimum ionizing particles. These must be balanced, however, against the difficult manual microscope measurement by skilled observers required for the analysis. We have developed an automated system to acquire and analyze the microscope images from emulsion chambers. Each emulsion plate is analyzed independently, allowing coincidence techniques to be used in order to reject background and estimate error rates. The system has been used to analyze a sample of high-multiplicity Pb-Pb interactions (charged particle multiplicities ∝ 1100) produced by the 158 GeV/c per nucleon 208 Pb beam at CERN. Automatically measured events agree with our best manual measurements on 97% of all the tracks. We describe the image analysis and track reconstruction techniques, and discuss the measurement and reconstruction uncertainties. (orig.)

Adaptive Statistical Iterative Reconstruction-V Versus Adaptive Statistical Iterative Reconstruction: Impact on Dose Reduction and Image Quality in Body Computed Tomography.

Science.gov (United States)

Gatti, Marco; Marchisio, Filippo; Fronda, Marco; Rampado, Osvaldo; Faletti, Riccardo; Bergamasco, Laura; Ropolo, Roberto; Fonio, Paolo

The aim of this study was to evaluate the impact on dose reduction and image quality of the new iterative reconstruction technique: adaptive statistical iterative reconstruction (ASIR-V). Fifty consecutive oncologic patients acted as case controls undergoing during their follow-up a computed tomography scan both with ASIR and ASIR-V. Each study was analyzed in a double-blinded fashion by 2 radiologists. Both quantitative and qualitative analyses of image quality were conducted. Computed tomography scanner radiation output was 38% (29%-45%) lower (P ASIR-V examinations than for the ASIR ones. The quantitative image noise was significantly lower (P ASIR-V. Adaptive statistical iterative reconstruction-V had a higher performance for the subjective image noise (P = 0.01 for 5 mm and P = 0.009 for 1.25 mm), the other parameters (image sharpness, diagnostic acceptability, and overall image quality) being similar (P > 0.05). Adaptive statistical iterative reconstruction-V is a new iterative reconstruction technique that has the potential to provide image quality equal to or greater than ASIR, with a dose reduction around 40%.

Challenges in the reconstruction of bilateral maxillectomy defects.

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Joseph, Shawn T; Thankappan, Krishnakumar; Buggaveeti, Rahul; Sharma, Mohit; Mathew, Jimmy; Iyer, Subramania

2015-02-01

Bilateral maxillectomy defects, if not adequately reconstructed, can result in grave esthetic and functional problems. The purpose of this study was to investigate the outcome of reconstruction of such defects. This is a retrospective case series. The defects were analyzed for their components and the flaps used for reconstruction. Outcomes for flap loss and functional indices, including oral diet, speech, and dental rehabilitation, also were evaluated. Ten consecutive patients who underwent bilateral maxillectomy reconstruction received 14 flaps. Six patients had malignancies of the maxilla, and 4 patients had nonmalignant indications. Ten bony free flaps were used. Four soft tissue flaps were used. The fibula free flap was the most common flap used. Three patients had total flap loss. Seven patients were alive and available for functional evaluation. Of these, 4 were taking an oral diet with altered consistency and 2 were on a regular diet. Speech was intelligible in all patients. Only 2 patients opted for dental rehabilitation with removable dentures. Reconstruction after bilateral maxillectomy is essential to prevent esthetic and functional problems. Bony reconstruction is ideal. The fibula bone free flap is commonly used. The complexity of the defect makes reconstruction difficult and the initial success rate of free flaps is low. Secondary reconstructions after the initial flap failures were successful. A satisfactory functional outcome can be achieved. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Usefulness of three dimensional reconstructive images for thoracic trauma induced fractures

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Koh, Kyung Hun; Kim, Dong Hun; Kim, Young Sook; Byun, Joo Nam [Chosun University Hospital, Gwangju (Korea, Republic of)

2006-09-15

We wanted to evaluate the usefulness of three-dimensional reconstructive images using multidetector computed tomography (MDCT) for thoracic traumatic patients visiting emergency room. 76 patients with fractures of the 105 patients who visited our emergency room with complaints of thoracic trauma were analyzed retrospectively. All the patients had thoracic MDCT performed and the three-dimensional reconstructive images were taken. The fractures were confirmed by axial CT, the clinical information, whole body bone scanning and the multiplanar reformation images. Plain x-ray images were analyzed by the fractured sites in a blind comparison of two radiologists' readings, and then that finding was compared with the axial CT scans and the three-dimensional reconstructive images. The fracture sites were rib (n 68), sternum (n = 14), clavicle (n = 6), scapula (n = 3), spine (n = 5) and combined fractures (n = 14). Plain x-ray and axial CT scans had a correspondency of 0.555 for the rib fractures. Axial CT scans and the three-dimensional reconstructive images had a correspondency of .952. For sternal fractures, those values were 0.692 and 0.928, respectively. The axial CT scans and three-dimensional reconstructive images showed sensitivities of 94% and 91% for rib and other fractures, respectively, and 93% and 100% for sternal fracture, respectively. Three-dimensional reconstructive image had an especially high sensitivity for the diagnosis of sternal fracture. While evaluating thoracic trauma at the emergency room, the three-dimensional reconstructive image was useful to easily diagnose the extent of fracture and it was very sensitive for detecting sternal fracture.

Usefulness of three dimensional reconstructive images for thoracic trauma induced fractures

International Nuclear Information System (INIS)

Koh, Kyung Hun; Kim, Dong Hun; Kim, Young Sook; Byun, Joo Nam

2006-01-01

We wanted to evaluate the usefulness of three-dimensional reconstructive images using multidetector computed tomography (MDCT) for thoracic traumatic patients visiting emergency room. 76 patients with fractures of the 105 patients who visited our emergency room with complaints of thoracic trauma were analyzed retrospectively. All the patients had thoracic MDCT performed and the three-dimensional reconstructive images were taken. The fractures were confirmed by axial CT, the clinical information, whole body bone scanning and the multiplanar reformation images. Plain x-ray images were analyzed by the fractured sites in a blind comparison of two radiologists' readings, and then that finding was compared with the axial CT scans and the three-dimensional reconstructive images. The fracture sites were rib (n 68), sternum (n = 14), clavicle (n = 6), scapula (n = 3), spine (n = 5) and combined fractures (n = 14). Plain x-ray and axial CT scans had a correspondency of 0.555 for the rib fractures. Axial CT scans and the three-dimensional reconstructive images had a correspondency of .952. For sternal fractures, those values were 0.692 and 0.928, respectively. The axial CT scans and three-dimensional reconstructive images showed sensitivities of 94% and 91% for rib and other fractures, respectively, and 93% and 100% for sternal fracture, respectively. Three-dimensional reconstructive image had an especially high sensitivity for the diagnosis of sternal fracture. While evaluating thoracic trauma at the emergency room, the three-dimensional reconstructive image was useful to easily diagnose the extent of fracture and it was very sensitive for detecting sternal fracture

Rock analyzes that could be key in biofuel production: student expands research in Germany: Escuela de Quimica sent to posgraduate student at Leipzig University

International Nuclear Information System (INIS)

O'neal Coto, Katzt; Puente Urbina, Allen

2014-01-01

University student of posgraduate in chemistry at the Universidad de Costa Rica has done an internship at the Universitat Leipzig, Germany. All the facilities were given to analyze samples of a type of sedimentary rock known as diatomite. The Nuclear Magnetic Resonance of Xenon was used to remove the fatty acids present in vegetable oil or animal fat used in the production of biodiesel [es

Bilateral simultaneous breast reconstruction with SGAP flaps.

Science.gov (United States)

Flores, Jaime I; Magarakis, Michael; Venkat, Raghunandan; Shridharani, Sachin M; Rosson, Gedge D

2012-07-01

Two work-horse approaches to postmastectomy breast reconstruction are the deep inferior epigastric perforator flap and the superior gluteal artery perforator (SGAP) flap [and its variation, the lateral septocutaneous superior gluteal artery perforator flap]. Our purpose was fourfold: 1) to analyze our experience with the SGAP flaps for simultaneous bilateral breast reconstruction; 2) to analyze our experience with lateral septocutaneous superior gluteal artery perforator flaps for that procedure; 3) to compare our results with those in the literature; and 4) to highlight the importance of preoperative three-dimensional computed tomographic angiography. A retrospective chart review was completed for 23 patients who underwent breast reconstruction between December 2005 and January 2010 via an SGAP flap (46 flaps). We reviewed flap weight, ischemia time, length of stay, overall flap survival, fat necrosis development, and emergency re-exploration. Mean weights were 571.2 ± 222.0 g (range 186-1,117 g) and 568.0 ± 237.5 g (range 209-1,115 g) for the left and right buttock flap, respectively. Mean ischemia time was 129.1 ± 15.7 and 177.7 ± 24.7 minutes for the first and second flap, respectively. Mean hospital stay was 5.3 ± 2.5 days. All flaps survived. Fat necrosis developed in five flaps (10.8%), and emergency re-exploration was required in three patients (three flaps). When harvesting abdominal tissue is a poor option, the SGAP flap is an efficacious procedure for patients desiring autologous breast reconstruction, and bilateral procedures can be performed simultaneously. Copyright © 2012 Wiley Periodicals, Inc.

Trends in breast reconstruction: Implications for the National Health Insurance Service.

Science.gov (United States)

Hong, Ki Yong; Son, Yoosung; Chang, Hak; Jin, Ung Sik

2018-05-01

Breast reconstruction has become more common as mastectomy has become more frequent. In Korea, the National Health Insurance Service (NHIS) began covering breast reconstruction in April 2015. This study aimed to investigate trends in mastectomy and breast reconstruction over the past 10 years and to evaluate the impact of NHIS coverage on breast reconstruction. Nationwide data regarding mastectomy and breast reconstruction were collected from the Korean Breast Cancer Society registry database. Multiple variables were analyzed in the records of patients who underwent breast reconstruction from January 2005 to March 2017 at a single institution. At Seoul National University Hospital, the total number of reconstruction cases increased 13-fold from 2005 to 2016. The proportion of immediate breast reconstruction (IBR) cases out of all cases of total mastectomy increased from 4% in 2005 to 52.0% in 2016. The proportion of delayed breast reconstruction (DBR) cases out of all cases of breast reconstruction and the overall number of DBR cases increased from 8.8% (20 cases) in 2012 to 18.3% (76 cases) in 2016. After NHIS coverage was initiated, the proportions of IBR and DBR showed statistically significant increases (PNHIS coverage (PNHIS coverage. It is expected that breast reconstruction will be a routine option for patients with breast cancer under the NHIS.

Multispectral x-ray CT: multivariate statistical analysis for efficient reconstruction

Science.gov (United States)

Kheirabadi, Mina; Mustafa, Wail; Lyksborg, Mark; Lund Olsen, Ulrik; Bjorholm Dahl, Anders

2017-10-01

Recent developments in multispectral X-ray detectors allow for an efficient identification of materials based on their chemical composition. This has a range of applications including security inspection, which is our motivation. In this paper, we analyze data from a tomographic setup employing the MultiX detector, that records projection data in 128 energy bins covering the range from 20 to 160 keV. Obtaining all information from this data requires reconstructing 128 tomograms, which is computationally expensive. Instead, we propose to reduce the dimensionality of projection data prior to reconstruction and reconstruct from the reduced data. We analyze three linear methods for dimensionality reduction using a dataset with 37 equally-spaced projection angles. Four bottles with different materials are recorded for which we are able to obtain similar discrimination of their content using a very reduced subset of tomograms compared to the 128 tomograms that would otherwise be needed without dimensionality reduction.

Energy reconstruction and calibration algorithms for the ATLAS electromagnetic calorimeter

CERN Document Server

Delmastro, M

2003-01-01

The work of this thesis is devoted to the study, development and optimization of the algorithms of energy reconstruction and calibration for the electromagnetic calorimeter (EMC) of the ATLAS experiment, presently under installation and commissioning at the CERN Large Hadron Collider in Geneva (Switzerland). A deep study of the electrical characteristics of the detector and of the signals formation and propagation is conduced: an electrical model of the detector is developed and analyzed through simulations; a hardware model (mock-up) of a group of the EMC readout cells has been built, allowing the direct collection and properties study of the signals emerging from the EMC cells. We analyze the existing multiple-sampled signal reconstruction strategy, showing the need of an improvement in order to reach the advertised performances of the detector. The optimal filtering reconstruction technique is studied and implemented, taking into account the differences between the ionization and calibration waveforms as e...

Identification of complications in mastectomy with immediate reconstruction using tissue expanders and permanent implants for breast cancer patients.

Science.gov (United States)

Ota, Daisuke; Fukuuchi, Atsushi; Iwahira, Yoshiko; Kato, Takao; Takeuchi, Masashi; Okamoto, Joji; Nishi, Tsunehiro

2016-05-01

Since complications of postmastectomy breast reconstruction may reduce patient satisfaction, we investigated complications of reconstruction with tissue expanders (TEs), particularly surgical site infections requiring TE/permanent implant (PI) removal. A retrospective review was performed of 234 primary breast cancer patients undergoing 239 postmastectomy breast reconstructions with TEs/PIs from 1997 to 2009. Clinicopathological findings and postoperative complications, particularly infections, were analyzed. Data were analyzed by the Chi-square test and a multivariate logistic regression model. TE infection risk factors considered for model inclusion were excisional biopsy, (neo) adjuvant chemotherapy, lymph node resection, body mass index (BMI), simultaneous bilateral reconstructions, and seroma aspiration. Removal of TEs/PIs was observed in 15.5% (37/239) of reconstructions, and 18/37 underwent re-reconstructions. Of the 19/37 reconstructions that were not achieved completely, the most frequent reason was TE infection (11 reconstructions). The completion rate was 92% (220/239 reconstructions) and it was significantly higher in reconstructions without TE infection than with infection (96 vs. 54%, p breast reconstruction, prevention of TE infection plays a key role. We should reduce unnecessary seroma aspirations and delay elevation/exercise of the ipsilateral arm.

Dependence of reconstructed image characteristics on the observation condition in light-in-flight recording by holography.

Science.gov (United States)

Komatsu, Aya; Awatsuji, Yasuhiro; Kubota, Toshihiro

2005-08-01

We analyze the dependence of the reconstructed image characteristic on the observation condition in the light-in-flight recording by holography both theoretically and experimentally. This holography makes it possible to record a propagating light pulse. We have found that the shape of the reconstructed image is changed when the observation position is vertically moved along the hologram plane. The reconstructed image is numerically simulated on the basis of the theory and is experimentally obtained by using a 373 fs pulsed laser. The numerical results agree with the experimental result, and the validity of the theory is verified. Also, experimental results are analyzed and the restoration of the reconstructed image is discussed.

Molecular Imaging : Computer Reconstruction and Practice - Proceedings of the NATO Advanced Study Institute on Molecular Imaging from Physical Principles to Computer Reconstruction and Practice

CERN Document Server

Lemoigne, Yves

2008-01-01

This volume collects the lectures presented at the ninth ESI School held at Archamps (FR) in November 2006 and is dedicated to nuclear physics applications in molecular imaging. The lectures focus on the multiple facets of image reconstruction processing and management and illustrate the role of digital imaging in clinical practice. Medical computing and image reconstruction are introduced by analysing the underlying physics principles and their implementation, relevant quality aspects, clinical performance and recent advancements in the field. Several stages of the imaging process are specifically addressed, e.g. optimisation of data acquisition and storage, distributed computing, physiology and detector modelling, computer algorithms for image reconstruction and measurement in tomography applications, for both clinical and biomedical research applications. All topics are presented with didactical language and style, making this book an appropriate reference for students and professionals seeking a comprehen...

Comparison of pure and hybrid iterative reconstruction techniques with conventional filtered back projection: Image quality assessment in the cervicothoracic region

International Nuclear Information System (INIS)

Katsura, Masaki; Sato, Jiro; Akahane, Masaaki; Matsuda, Izuru; Ishida, Masanori; Yasaka, Koichiro; Kunimatsu, Akira; Ohtomo, Kuni

2013-01-01

Objectives: To evaluate the impact on image quality of three different image reconstruction techniques in the cervicothoracic region: model-based iterative reconstruction (MBIR), adaptive statistical iterative reconstruction (ASIR), and filtered back projection (FBP). Methods: Forty-four patients underwent unenhanced standard-of-care clinical computed tomography (CT) examinations which included the cervicothoracic region with a 64-row multidetector CT scanner. Images were reconstructed with FBP, 50% ASIR-FBP blending (ASIR50), and MBIR. Two radiologists assessed the cervicothoracic region in a blinded manner for streak artifacts, pixilated blotchy appearances, critical reproduction of visually sharp anatomical structures (thyroid gland, common carotid artery, and esophagus), and overall diagnostic acceptability. Objective image noise was measured in the internal jugular vein. Data were analyzed using the sign test and pair-wise Student's t-test. Results: MBIR images had significant lower quantitative image noise (8.88 ± 1.32) compared to ASIR images (18.63 ± 4.19, P 0.9 for ASIR vs. FBP for both readers). MBIR images were all diagnostically acceptable. Unique features of MBIR images included pixilated blotchy appearances, which did not adversely affect diagnostic acceptability. Conclusions: MBIR significantly improves image noise and streak artifacts of the cervicothoracic region over ASIR and FBP. MBIR is expected to enhance the value of CT examinations for areas where image noise and streak artifacts are problematic

Three-dimensional reconstruction and segmentation of intact Drosophila by ultramicroscopy

Directory of Open Access Journals (Sweden)

Nina Jährling

2010-02-01

Full Text Available Genetic mutants are invaluable for understanding the development, physiology and behaviour of Drosophila. Modern molecular genetic techniques enable the rapid generation of large numbers of different mutants. To phenotype these mutants sophisticated microscopy techniques are required, ideally allowing the 3D-reconstruction of the anatomy of an adult fly from a single scan. Ultramicroscopy enables up to cm fields of view, whilst providing micron resolution. In this paper, we present ultramicroscopy reconstructions of the flight musculature, the nervous system, and the digestive tract of entire, chemically cleared, drosophila in autofluorescent light. The 3D-reconstructions thus obtained verify that the anatomy of a whole fly, including the filigree spatial organisation of the direct flight muscles, can be analyzed from a single ultramicroscopy reconstruction. The recording procedure, including 3D-reconstruction using standard software, takes no longer than 30 minutes. Additionally, image segmentation, which would allow for further quantitative analysis, was performed.

Fast parallel algorithm for CT image reconstruction.

Science.gov (United States)

Flores, Liubov A; Vidal, Vicent; Mayo, Patricia; Rodenas, Francisco; Verdú, Gumersindo

2012-01-01

In X-ray computed tomography (CT) the X rays are used to obtain the projection data needed to generate an image of the inside of an object. The image can be generated with different techniques. Iterative methods are more suitable for the reconstruction of images with high contrast and precision in noisy conditions and from a small number of projections. Their use may be important in portable scanners for their functionality in emergency situations. However, in practice, these methods are not widely used due to the high computational cost of their implementation. In this work we analyze iterative parallel image reconstruction with the Portable Extensive Toolkit for Scientific computation (PETSc).

Time-of-flight PET image reconstruction using origin ensembles

Science.gov (United States)

Wülker, Christian; Sitek, Arkadiusz; Prevrhal, Sven

2015-03-01

The origin ensemble (OE) algorithm is a novel statistical method for minimum-mean-square-error (MMSE) reconstruction of emission tomography data. This method allows one to perform reconstruction entirely in the image domain, i.e. without the use of forward and backprojection operations. We have investigated the OE algorithm in the context of list-mode (LM) time-of-flight (TOF) PET reconstruction. In this paper, we provide a general introduction to MMSE reconstruction, and a statistically rigorous derivation of the OE algorithm. We show how to efficiently incorporate TOF information into the reconstruction process, and how to correct for random coincidences and scattered events. To examine the feasibility of LM-TOF MMSE reconstruction with the OE algorithm, we applied MMSE-OE and standard maximum-likelihood expectation-maximization (ML-EM) reconstruction to LM-TOF phantom data with a count number typically registered in clinical PET examinations. We analyzed the convergence behavior of the OE algorithm, and compared reconstruction time and image quality to that of the EM algorithm. In summary, during the reconstruction process, MMSE-OE contrast recovery (CRV) remained approximately the same, while background variability (BV) gradually decreased with an increasing number of OE iterations. The final MMSE-OE images exhibited lower BV and a slightly lower CRV than the corresponding ML-EM images. The reconstruction time of the OE algorithm was approximately 1.3 times longer. At the same time, the OE algorithm can inherently provide a comprehensive statistical characterization of the acquired data. This characterization can be utilized for further data processing, e.g. in kinetic analysis and image registration, making the OE algorithm a promising approach in a variety of applications.

A Didactic Reconstruction of the Financial and Economic Crisis

Directory of Open Access Journals (Sweden)

Michael Schuhen

2010-08-01

Full Text Available Theoretical approaches to constructivism have put learner autonomy into the spotlight of didactic discourse. Apart from the matter of pedagogic actions on how (constructivisticly organised education might be arranged, this paper focuses on the perspective of didactic reconstruction. Thus, an observation-based research perspective is being adopted in this paper. The epistemic beliefs that have emerged over the course of the global financial and economic depression are reconstructed. The goal of the paper is to provide an insight into these different interpretations. In order to do this, university students were surveyed regarding this topic and the results of this qualitative study on these epistemic beliefs will be represented in this article. The paper tries to give answers on how students, who have been experiencing the financial and economic depression for nearly three years now, define its causes and what subsequent actions they would recommend. The results show that the main issue is not misinterpretation of political and economic knowledge but rather incomplete constructs based on only approximate knowledge.

Alpha image reconstruction (AIR): A new iterative CT image reconstruction approach using voxel-wise alpha blending

International Nuclear Information System (INIS)

Hofmann, Christian; Sawall, Stefan; Knaup, Michael; Kachelrieß, Marc

2014-01-01

Purpose: Iterative image reconstruction gains more and more interest in clinical routine, as it promises to reduce image noise (and thereby patient dose), to reduce artifacts, or to improve spatial resolution. Among vendors and researchers, however, there is no consensus of how to best achieve these aims. The general approach is to incorporatea priori knowledge into iterative image reconstruction, for example, by adding additional constraints to the cost function, which penalize variations between neighboring voxels. However, this approach to regularization in general poses a resolution noise trade-off because the stronger the regularization, and thus the noise reduction, the stronger the loss of spatial resolution and thus loss of anatomical detail. The authors propose a method which tries to improve this trade-off. The proposed reconstruction algorithm is called alpha image reconstruction (AIR). One starts with generating basis images, which emphasize certain desired image properties, like high resolution or low noise. The AIR algorithm reconstructs voxel-specific weighting coefficients that are applied to combine the basis images. By combining the desired properties of each basis image, one can generate an image with lower noise and maintained high contrast resolution thus improving the resolution noise trade-off. Methods: All simulations and reconstructions are performed in native fan-beam geometry. A water phantom with resolution bar patterns and low contrast disks is simulated. A filtered backprojection (FBP) reconstruction with a Ram-Lak kernel is used as a reference reconstruction. The results of AIR are compared against the FBP results and against a penalized weighted least squares reconstruction which uses total variation as regularization. The simulations are based on the geometry of the Siemens Somatom Definition Flash scanner. To quantitatively assess image quality, the authors analyze line profiles through resolution patterns to define a contrast

CT coronary angiography: Influence of different cardiac reconstruction intervals on image quality and diagnostic accuracy

Energy Technology Data Exchange (ETDEWEB)

Dewey, Marc [Department of Radiology, Charite Medical School, Humboldt-Universitaet zu Berlin (Germany)], E-mail: marc.dewey@charite.de; Teige, Florian [Department of Radiology, Charite Medical School, Humboldt-Universitaet zu Berlin (Germany); Rutsch, Wolfgang [Department of Cardiology, Charite Medical School, Humboldt-Universitaet zu Berlin (Germany)], E-mail: wolfgang.rutsch@charite.de; Schink, Tania [Department of Medical Biometry, Charite Medical School, Humboldt-Universitaet zu Berlin (Germany)], E-mail: peter.martus@charite.de; Hamm, Bernd [Department of Radiology, Charite Medical School, Humboldt-Universitaet zu Berlin (Germany)

2008-07-15

Purpose: To prospectively analyze image quality and diagnostic accuracy of different reconstruction intervals of coronary angiography using multislice computed tomography (MSCT). Materials and methods: For each of 47 patients, 10 ECG-gated MSCT reconstructions were generated throughout the RR interval from 0 to 90%, resulting in altogether 470 datasets. These datasets were randomly analyzed for image quality and accuracy and compared with conventional angiography. Statistical comparison of intervals was performed using nonparametric analysis for repeated measurements to account for clustering of arteries within patients. Results: Image reconstruction intervals centered at 80, 70, and 40% of the RR interval resulted (in that order) in the best overall image quality for all four main coronary vessels. Eighty percent reconstructions also yielded the highest diagnostic accuracy of all intervals. The combination of the three best intervals (80, 70, and 40%) significantly reduced the nondiagnostic rate as compared with 80% alone (p = 0.005). However, the optimal reconstruction interval combination achieved significantly improved specificities and nondiagnostic rates (p < 0.05). The optimal combination consisted of 1.7 {+-} 0.9 reconstruction intervals on average. In approximately half of the patients (49%, 23/47) a single reconstruction was optimal. In 18 (38%), 3 (6%), and 3 (6%) patients one, two, and three additional reconstruction intervals were required, respectively, to achieve optimal quality. In 28% of the patients the optimal combination consisted of reconstructions other than the three best intervals (80, 70, and 40%). Conclusion: Multiple image reconstruction intervals are essential to ensure high image quality and accuracy of CT coronary angiography.

Fast approach to evaluate MAP reconstruction for lesion detection and localization

International Nuclear Information System (INIS)

Qi, Jinyi; Huesman, Ronald H.

2004-01-01

Lesion detection is an important task in emission tomography. Localization ROC (LROC) studies are often used to analyze the lesion detection and localization performance. Most researchers rely on Monte Carlo reconstruction samples to obtain LROC curves, which can be very time-consuming for iterative algorithms. In this paper we develop a fast approach to obtain LROC curves that does not require Monte Carlo reconstructions. We use a channelized Hotelling observer model to search for lesions, and the results can be easily extended to other numerical observers. We theoretically analyzed the mean and covariance of the observer output. Assuming the observer outputs are multivariate Gaussian random variables, an LROC curve can be directly generated by integrating the conditional probability density functions. The high-dimensional integrals are calculated using a Monte Carlo method. The proposed approach is very fast because no iterative reconstruction is involved. Computer simulations show that the results of the proposed method match well with those obtained using the tradition LROC analysis

Isokinetic Testing in Evaluation Rehabilitation Outcome After ACL Reconstruction.

Science.gov (United States)

Cvjetkovic, Dragana Dragicevic; Bijeljac, Sinisa; Palija, Stanislav; Talic, Goran; Radulovic, Tatjana Nozica; Kosanovic, Milkica Glogovac; Manojlovic, Slavko

2015-02-01

Numerous rehab protocols have been used in rehabilitation after ACL reconstruction. Isokinetic testing is an objective way to evaluate dynamic stability of the knee joint that estimates the quality of rehabilitation outcome after ACL reconstruction. Our investigation goal was to show importance of isokinetic testing in evaluation thigh muscle strength in patients which underwent ACL reconstruction and rehabilitation protocol. In prospective study, we evaluated 40 subjects which were divided into two groups. Experimental group consisted of 20 recreational males which underwent ACL reconstruction with hamstring tendon and rehabilitation protocol 6 months before isokinetic testing. Control group (20 subjects) consisted of healthy recreational males. In all subjects knee muscle testing was performed on a Biodex System 4 Pro isokinetic dynamo-meter et velocities of 60°/s and 180°/s. We followed average peak torque to body weight (PT/BW) and classic H/Q ratio. In statistical analysis Student's T test was used. There were statistically significant differences between groups in all evaluated parameters except of the mean value of PT/BW of the quadriceps et velocity of 60°/s (p>0.05). Isokinetic testing of dynamic stabilizers of the knee is need in diagnostic and treatment thigh muscle imbalance. We believe that isokinetic testing is an objective parameter for return to sport activities after ACL reconstruction.

Failed medial patellofemoral ligament reconstruction: Causes and surgical strategies

Science.gov (United States)

Sanchis-Alfonso, Vicente; Montesinos-Berry, Erik; Ramirez-Fuentes, Cristina; Leal-Blanquet, Joan; Gelber, Pablo E; Monllau, Joan Carles

2017-01-01

Patellar instability is a common clinical problem encountered by orthopedic surgeons specializing in the knee. For patients with chronic lateral patellar instability, the standard surgical approach is to stabilize the patella through a medial patellofemoral ligament (MPFL) reconstruction. Foreseeably, an increasing number of revision surgeries of the reconstructed MPFL will be seen in upcoming years. In this paper, the causes of failed MPFL reconstruction are analyzed: (1) incorrect surgical indication or inappropriate surgical technique/patient selection; (2) a technical error; and (3) an incorrect assessment of the concomitant risk factors for instability. An understanding of the anatomy and biomechanics of the MPFL and cautiousness with the imaging techniques while favoring clinical over radiological findings and the use of common sense to determine the adequate surgical technique for each particular case, are critical to minimizing MPFL surgery failure. Additionally, our approach to dealing with failure after primary MPFL reconstruction is also presented. PMID:28251062

Penalized maximum likelihood reconstruction for x-ray differential phase-contrast tomography

International Nuclear Information System (INIS)

Brendel, Bernhard; Teuffenbach, Maximilian von; Noël, Peter B.; Pfeiffer, Franz; Koehler, Thomas

2016-01-01

Purpose: The purpose of this work is to propose a cost function with regularization to iteratively reconstruct attenuation, phase, and scatter images simultaneously from differential phase contrast (DPC) acquisitions, without the need of phase retrieval, and examine its properties. Furthermore this reconstruction method is applied to an acquisition pattern that is suitable for a DPC tomographic system with continuously rotating gantry (sliding window acquisition), overcoming the severe smearing in noniterative reconstruction. Methods: We derive a penalized maximum likelihood reconstruction algorithm to directly reconstruct attenuation, phase, and scatter image from the measured detector values of a DPC acquisition. The proposed penalty comprises, for each of the three images, an independent smoothing prior. Image quality of the proposed reconstruction is compared to images generated with FBP and iterative reconstruction after phase retrieval. Furthermore, the influence between the priors is analyzed. Finally, the proposed reconstruction algorithm is applied to experimental sliding window data acquired at a synchrotron and results are compared to reconstructions based on phase retrieval. Results: The results show that the proposed algorithm significantly increases image quality in comparison to reconstructions based on phase retrieval. No significant mutual influence between the proposed independent priors could be observed. Further it could be illustrated that the iterative reconstruction of a sliding window acquisition results in images with substantially reduced smearing artifacts. Conclusions: Although the proposed cost function is inherently nonconvex, it can be used to reconstruct images with less aliasing artifacts and less streak artifacts than reconstruction methods based on phase retrieval. Furthermore, the proposed method can be used to reconstruct images of sliding window acquisitions with negligible smearing artifacts

Reconstructing bidimensional scalar field theory models

International Nuclear Information System (INIS)

Flores, Gabriel H.; Svaiter, N.F.

2001-07-01

In this paper we review how to reconstruct scalar field theories in two dimensional spacetime starting from solvable Scrodinger equations. Theree different Schrodinger potentials are analyzed. We obtained two new models starting from the Morse and Scarf II hyperbolic potencials, the U (θ) θ 2 In 2 (θ 2 ) model and U (θ) = θ 2 cos 2 (In(θ 2 )) model respectively. (author)

State reconstruction of one-dimensional wave packets

Science.gov (United States)

Krähmer, D. S.; Leonhardt, U.

1997-12-01

We review and analyze the method [U. Leonhardt, M.G. Raymer: Phys. Rev. Lett. 76, 1985 (1996)] for quantum-state reconstruction of one-dimensional non-relativistic wave packets from position observations. We illuminate the theoretical background of the technique and show how to extend the procedure to the continuous part of the spectrum.

Adaptive multiresolution method for MAP reconstruction in electron tomography

Energy Technology Data Exchange (ETDEWEB)

Acar, Erman, E-mail: erman.acar@tut.fi [Department of Signal Processing, Tampere University of Technology, P.O. Box 553, FI-33101 Tampere (Finland); BioMediTech, Tampere University of Technology, Biokatu 10, 33520 Tampere (Finland); Peltonen, Sari; Ruotsalainen, Ulla [Department of Signal Processing, Tampere University of Technology, P.O. Box 553, FI-33101 Tampere (Finland); BioMediTech, Tampere University of Technology, Biokatu 10, 33520 Tampere (Finland)

2016-11-15

3D image reconstruction with electron tomography holds problems due to the severely limited range of projection angles and low signal to noise ratio of the acquired projection images. The maximum a posteriori (MAP) reconstruction methods have been successful in compensating for the missing information and suppressing noise with their intrinsic regularization techniques. There are two major problems in MAP reconstruction methods: (1) selection of the regularization parameter that controls the balance between the data fidelity and the prior information, and (2) long computation time. One aim of this study is to provide an adaptive solution to the regularization parameter selection problem without having additional knowledge about the imaging environment and the sample. The other aim is to realize the reconstruction using sequences of resolution levels to shorten the computation time. The reconstructions were analyzed in terms of accuracy and computational efficiency using a simulated biological phantom and publically available experimental datasets of electron tomography. The numerical and visual evaluations of the experiments show that the adaptive multiresolution method can provide more accurate results than the weighted back projection (WBP), simultaneous iterative reconstruction technique (SIRT), and sequential MAP expectation maximization (sMAPEM) method. The method is superior to sMAPEM also in terms of computation time and usability since it can reconstruct 3D images significantly faster without requiring any parameter to be set by the user. - Highlights: • An adaptive multiresolution reconstruction method is introduced for electron tomography. • The method provides more accurate results than the conventional reconstruction methods. • The missing wedge and noise problems can be compensated by the method efficiently.

Model-based iterative reconstruction technique for radiation dose reduction in chest CT: comparison with the adaptive statistical iterative reconstruction technique

Energy Technology Data Exchange (ETDEWEB)

Katsura, Masaki; Matsuda, Izuru; Akahane, Masaaki; Sato, Jiro; Akai, Hiroyuki; Yasaka, Koichiro; Kunimatsu, Akira; Ohtomo, Kuni [University of Tokyo, Department of Radiology, Graduate School of Medicine, Bunkyo-ku, Tokyo (Japan)

2012-08-15

To prospectively evaluate dose reduction and image quality characteristics of chest CT reconstructed with model-based iterative reconstruction (MBIR) compared with adaptive statistical iterative reconstruction (ASIR). One hundred patients underwent reference-dose and low-dose unenhanced chest CT with 64-row multidetector CT. Images were reconstructed with 50 % ASIR-filtered back projection blending (ASIR50) for reference-dose CT, and with ASIR50 and MBIR for low-dose CT. Two radiologists assessed the images in a blinded manner for subjective image noise, artefacts and diagnostic acceptability. Objective image noise was measured in the lung parenchyma. Data were analysed using the sign test and pair-wise Student's t-test. Compared with reference-dose CT, there was a 79.0 % decrease in dose-length product with low-dose CT. Low-dose MBIR images had significantly lower objective image noise (16.93 {+-} 3.00) than low-dose ASIR (49.24 {+-} 9.11, P < 0.01) and reference-dose ASIR images (24.93 {+-} 4.65, P < 0.01). Low-dose MBIR images were all diagnostically acceptable. Unique features of low-dose MBIR images included motion artefacts and pixellated blotchy appearances, which did not adversely affect diagnostic acceptability. Diagnostically acceptable chest CT images acquired with nearly 80 % less radiation can be obtained using MBIR. MBIR shows greater potential than ASIR for providing diagnostically acceptable low-dose CT images without severely compromising image quality. (orig.)

Real-time position reconstruction with hippocampal place cells.

Science.gov (United States)

Guger, Christoph; Gener, Thomas; Pennartz, Cyriel M A; Brotons-Mas, Jorge R; Edlinger, Günter; Bermúdez I Badia, S; Verschure, Paul; Schaffelhofer, Stefan; Sanchez-Vives, Maria V

2011-01-01

Brain-computer interfaces (BCI) are using the electroencephalogram, the electrocorticogram and trains of action potentials as inputs to analyze brain activity for communication purposes and/or the control of external devices. Thus far it is not known whether a BCI system can be developed that utilizes the states of brain structures that are situated well below the cortical surface, such as the hippocampus. In order to address this question we used the activity of hippocampal place cells (PCs) to predict the position of an rodent in real-time. First, spike activity was recorded from the hippocampus during foraging and analyzed off-line to optimize the spike sorting and position reconstruction algorithm of rats. Then the spike activity was recorded and analyzed in real-time. The rat was running in a box of 80 cm × 80 cm and its locomotor movement was captured with a video tracking system. Data were acquired to calculate the rat's trajectories and to identify place fields. Then a Bayesian classifier was trained to predict the position of the rat given its neural activity. This information was used in subsequent trials to predict the rat's position in real-time. The real-time experiments were successfully performed and yielded an error between 12.2 and 17.4% using 5-6 neurons. It must be noted here that the encoding step was done with data recorded before the real-time experiment and comparable accuracies between off-line (mean error of 15.9% for three rats) and real-time experiments (mean error of 14.7%) were achieved. The experiment shows proof of principle that position reconstruction can be done in real-time, that PCs were stable and spike sorting was robust enough to generalize from the training run to the real-time reconstruction phase of the experiment. Real-time reconstruction may be used for a variety of purposes, including creating behavioral-neuronal feedback loops or for implementing neuroprosthetic control.

A new iterative algorithm to reconstruct the refractive index.

Science.gov (United States)

Liu, Y J; Zhu, P P; Chen, B; Wang, J Y; Yuan, Q X; Huang, W X; Shu, H; Li, E R; Liu, X S; Zhang, K; Ming, H; Wu, Z Y

2007-06-21

The latest developments in x-ray imaging are associated with techniques based on the phase contrast. However, the image reconstruction procedures demand significant improvements of the traditional methods, and/or new algorithms have to be introduced to take advantage of the high contrast and sensitivity of the new experimental techniques. In this letter, an improved iterative reconstruction algorithm based on the maximum likelihood expectation maximization technique is presented and discussed in order to reconstruct the distribution of the refractive index from data collected by an analyzer-based imaging setup. The technique considered probes the partial derivative of the refractive index with respect to an axis lying in the meridional plane and perpendicular to the propagation direction. Computer simulations confirm the reliability of the proposed algorithm. In addition, the comparison between an analytical reconstruction algorithm and the iterative method has been also discussed together with the convergent characteristic of this latter algorithm. Finally, we will show how the proposed algorithm may be applied to reconstruct the distribution of the refractive index of an epoxy cylinder containing small air bubbles of about 300 micro of diameter.

Probability Density Function Method for Observing Reconstructed Attractor Structure

Institute of Scientific and Technical Information of China (English)

陆宏伟; 陈亚珠; 卫青

2004-01-01

Probability density function (PDF) method is proposed for analysing the structure of the reconstructed attractor in computing the correlation dimensions of RR intervals of ten normal old men. PDF contains important information about the spatial distribution of the phase points in the reconstructed attractor. To the best of our knowledge, it is the first time that the PDF method is put forward for the analysis of the reconstructed attractor structure. Numerical simulations demonstrate that the cardiac systems of healthy old men are about 6 - 6.5 dimensional complex dynamical systems. It is found that PDF is not symmetrically distributed when time delay is small, while PDF satisfies Gaussian distribution when time delay is big enough. A cluster effect mechanism is presented to explain this phenomenon. By studying the shape of PDFs, that the roles played by time delay are more important than embedding dimension in the reconstruction is clearly indicated. Results have demonstrated that the PDF method represents a promising numerical approach for the observation of the reconstructed attractor structure and may provide more information and new diagnostic potential of the analyzed cardiac system.

Application of CT three-dimensional reconstruction in elbow injury

International Nuclear Information System (INIS)

Liang Wenhua; Qian Li

2009-01-01

Objective: To investigate the application of multi-slice spiral CT in fracture of elbow, and to study the value of different methods of the reconstruction. Methods: Thin line cross-section spiral CT scan was carried out in 13 cases with elbow injury, three-dimensional reconstruction was completed later. Several reconstructed image quality to display f the elbow fracture and dislocation were analyzed and compared. Results: 13 cases (17) elbow trauma included humeral media epicondyle fracture, humeral external epicondyle fracture, intercondylar fracture, olecranal fracture and radial head fracture. Among them, X-ray film showed negative in three sites, showed suspect fractures in 2 cases, and only showed single fracture in 2 cases. MPR reconstruction image could not only identify the diagnosis of fracture, but also provide further multi-angle display on fracture line and the extent of articular surface involvement. Surface reconstruction technology could exclude the impact of passive elbow flexion and display elbow injury more intuitively. Conclusion The elbow fracture dislocation could be showed clearly in multi-slice spiral CT, especially for complex fractures, with unmatched advantages compared to X-ray for clinical diagnosis and treatment determination. (authors)

Image reconstruction. Application to transverse axial tomography

International Nuclear Information System (INIS)

Aubry, Florent.

1977-09-01

A method of computerized tridimensional image reconstruction from their projection, especially in the computerized transverse axial tomography is suggested. First, the different techniques actually developped and presented in the literature are analyzed. Then, the equipment used is briefly described. The reconstruction algorithm developped is presented. This algorithm is based on the convolution method, well adapted to the real conditions of exploitation. It is an extension of SHEPP and LOGAN's algorithm. A correction of the self absorption and of the detector's response is proposed. Finally, the first results obtained which are satisfactory are given. The simplicity of the method which does not need a too long computation time makes possible the implementation of the algorithm on a mini-computer [fr

Identify the Rotating Stall in Centrifugal Compressors by Fractal Dimension in Reconstructed Phase Space

Directory of Open Access Journals (Sweden)

Le Wang

2015-11-01

Full Text Available Based on phase space reconstruction and fractal dynamics in nonlinear dynamics, a method is proposed to extract and analyze the dynamics of the rotating stall in the impeller of centrifugal compressor, and some numerical examples are given to verify the results as well. First, the rotating stall of an existing low speed centrifugal compressor (LSCC is numerically simulated, and the time series of pressure in the rotating stall is obtained at various locations near the impeller outlet. Then, the phase space reconstruction is applied to these pressure time series, and a low-dimensional dynamical system, which the dynamics properties are included in, is reconstructed. In phase space reconstruction, C–C method is used to obtain the key parameters, such as time delay and the embedding dimension of the reconstructed phase space. Further, the fractal characteristics of the rotating stall are analyzed in detail, and the fractal dimensions are given for some examples to measure the complexity of the flow in the post-rotating stall. The results show that the fractal structures could reveal the intrinsic dynamics of the rotating stall flow and could be considered as a characteristic to identify the rotating stall.

Algebraic reconstruction techniques for spectral reconstruction in diffuse optical tomography

International Nuclear Information System (INIS)

Brendel, Bernhard; Ziegler, Ronny; Nielsen, Tim

2008-01-01

Reconstruction in diffuse optical tomography (DOT) necessitates solving the diffusion equation, which is nonlinear with respect to the parameters that have to be reconstructed. Currently applied solving methods are based on the linearization of the equation. For spectral three-dimensional reconstruction, the emerging equation system is too large for direct inversion, but the application of iterative methods is feasible. Computational effort and speed of convergence of these iterative methods are crucial since they determine the computation time of the reconstruction. In this paper, the iterative methods algebraic reconstruction technique (ART) and conjugated gradients (CGs) as well as a new modified ART method are investigated for spectral DOT reconstruction. The aim of the modified ART scheme is to speed up the convergence by considering the specific conditions of spectral reconstruction. As a result, it converges much faster to favorable results than conventional ART and CG methods

78 FR 58589 - Final Listing of Audit and Other Reports Issued by SIGIR on Reconstruction Spending in Iraq

Science.gov (United States)

2013-09-24

... 12-017 Final Forensic Audit Report of Iraq Reconstruction Funds 7/13/ 2012 12-016 Interim Review of.../2011 11-006 Forensic Audit Methodologies Used To Collect and Analyze Electronic Disbursement of Iraq Reconstruction Funds 10/28/2010 11-005 Iraq Reconstruction Funds: Forensic Audits Identifying Fraud, Waste, and...

Engaging Middle School Students with Google Earth Technology to Analyze Ocean Cores as Evidence for Sea Floor Spreading

Science.gov (United States)

Prouhet, T.; Cook, J.

2006-12-01

Google Earth's ability to captivate students' attention, its ease of use, and its high quality images give it the potential to be an extremely effective tool for earth science educators. The unique properties of Google Earth satisfy a growing demand to incorporate technology in science instruction. Google Earth is free and relatively easy to use unlike some other visualization software. Students often have difficulty conceptualizing and visualizing earth systems, such as deep-ocean basins, because of the complexity and dynamic nature of the processes associated with them (e.g. plate tectonics). Google Earth's combination of aerial photography, satellite images and remote sensing data brings a sense of realism to science concepts. The unobstructed view of the ocean floor provided by this technology illustrates three-dimensional subsurface features such as rift valleys, subduction zones, and sea-mounts enabling students to better understand the seafloor's dynamic nature. Students will use Google Earth to navigate the sea floor, and examine Deep Sea Drilling Project (DSDP) core locations the from the Glomar Challenger Leg 3 expedition. The lesson to be implemented was expanded upon and derived from the Joint Oceanographic Insitute (JOI) Learning exercise, Nannofossils Reveal Seafloor Spreading. In addition, students take on the role of scientists as they graph and analyze paleontological data against the distance from the Mid Ocean Ridge. The integration of ocean core data in this three-dimensional view aids students' ability to draw and communicate valid conclusions about their scientific observations. A pre and post survey will be given to examine attitudes, self-efficacy, achievement and content mastery to a sample of approximately 300 eighth grade science students. The hypothesis is that the integration of Google Earth will significantly improve all areas of focus as mentioned above.

Content analysis of medical students' seminars: a unique method of analyzing clinical thinking.

Science.gov (United States)

Takata, Yukari; Stein, Gerald H; Endo, Kuniyuki; Arai, Akiko; Kohsaka, Shun; Kitano, Yuka; Honda, Hitoshi; Kitazono, Hidetaka; Tokunaga, Hironobu; Tokuda, Yasuharu; Obika, Mikako; Miyoshi, Tomoko; Kataoka, Hitomi; Terasawa, Hidekazu

2013-12-01

The study of communication skills of Asian medical students during structured Problem-based Learning (PBL) seminars represented a unique opportunity to assess their critical thinking development. This study reports the first application of the health education technology, content analysis (CA), to a Japanese web-based seminar (webinar). The authors assigned twelve randomly selected medical students from two universities and two clinical instructors to two virtual classrooms for four PBL structured tutoring sessions that were audio-video captured for CA. Both of the instructors were US-trained physicians. This analysis consisted of coding the students' verbal comments into seven types, ranging from trivial to advanced knowledge integration comments that served as a proxy for clinical thinking. The most basic level of verbal simple responses accounted for a majority (85%) of the total students' verbal comments. Only 15% of the students' comments represented more advanced types of critical thinking. The male students responded more than the female students; male students attending University 2 responded more than male students from University 1. The total mean students' verbal response time for the four sessions with the male instructor was 6.9%; total mean students' verbal response time for the four sessions with the female instructor was 19% (p thinking for medical students. This report may stimulate improvements for implementation.

General relativity in upper secondary school: Design and evaluation of an online learning environment using the model of educational reconstruction

Science.gov (United States)

Kersting, Magdalena; Henriksen, Ellen Karoline; Bøe, Maria Vetleseter; Angell, Carl

2018-06-01

Because of its abstract nature, Albert Einstein's theory of general relativity is rarely present in school physics curricula. Although the educational community has started to investigate ways of bringing general relativity to classrooms, field-tested educational material is rare. Employing the model of educational reconstruction, we present a collaborative online learning environment that was introduced to final year students (18-19 years old) in six Norwegian upper secondary physics classrooms. Design-based research methods guided the development of the learning resources, which were based on a sociocultural view of learning and a historical-philosophical approach to teaching general relativity. To characterize students' learning from and interaction with the learning environment we analyzed focus group interviews and students' oral and written responses to assigned problems and discussion tasks. Our findings show how design choices on different levels can support or hinder understanding of general relativity, leading to the formulation of design principles that help to foster qualitative understanding and encourage collaborative learning. The results indicate that upper secondary students can obtain a qualitative understanding of general relativity when provided with appropriately designed learning resources and sufficient scaffolding of learning through interaction with teacher and peers.

Improvement of graphite crystal analyzer for light elements on X-ray fluorescence holography measurement

Science.gov (United States)

Happo, Naohisa; Hada, Takuma; Kubota, Atsushi; Ebisu, Yoshihiro; Hosokawa, Shinya; Kimura, Koji; Tajiri, Hiroo; Matsushita, Tomohiro; Hayashi, Kouichi

2018-05-01

Using a graphite crystal analyzer, focused monochromatic fluorescent X-rays can be obtained on an X-ray fluorescence holography (XFH) measurement. To measure the holograms of elements lighter than Ti, we improved a cylindrical-type crystal analyzer and constructed a small C-shaped analyzer. Using the constructed C-shaped analyzer, a Ca Kα hologram of a fluorite single crystal was obtained, from which we reconstructed a clear atomic image. The XFH measurements for the K, Ca, and Sc elements become possible using the presently constructed analyzer.

Pseudocode Interpreter (Pseudocode Integrated Development Environment with Lexical Analyzer and Syntax Analyzer using Recursive Descent Parsing Algorithm

Directory of Open Access Journals (Sweden)

Christian Lester D. Gimeno

2017-11-01

Full Text Available –This research study focused on the development of a software that helps students design, write, validate and run their pseudocode in a semi Integrated Development Environment (IDE instead of manually writing it on a piece of paper.Specifically, the study aimed to develop lexical analyzer or lexer, syntax analyzer or parser using recursive descent parsing algorithm and an interpreter. The lexical analyzer reads pseudocodesource in a sequence of symbols or characters as lexemes.The lexemes are then analyzed by the lexer that matches a pattern for valid tokens and passes to the syntax analyzer or parser. The syntax analyzer or parser takes those valid tokens and builds meaningful commands using recursive descent parsing algorithm in a form of an abstract syntax tree. The generation of an abstract syntax tree is based on the specified grammar rule created by the researcher expressed in Extended Backus-Naur Form. The Interpreter takes the generated abstract syntax tree and starts the evaluation or interpretation to produce pseudocode output. The software was evaluated using white-box testing by several ICT professionals and black-box testing by several computer science students based on the International Organization for Standardization (ISO 9126 software quality standards. The overall results of the evaluation both for white-box and black-box were described as “Excellent in terms of functionality, reliability, usability, efficiency, maintainability and portability”.

Who is the competent physics student? A study of students' positions and social interaction in small-group discussions

Science.gov (United States)

Due, Karin

2014-06-01

This article describes a study which explored the social interaction and the reproduction and challenge of gendered discourses in small group discussions in physics. Data for the study consisted of video recordings of eight upper secondary school groups solving physics problems and 15 audiotaped individual interviews with participating students. The analysis was based on gender theory viewing gender both as a process and a discourse. Specifically discursive psychology analysis was used to examine how students position themselves and their peers within discourses of physics and gender. The results of the study reveal how images of physics and of "skilled physics student" were constructed in the context of the interviews. These discourses were reconstructed in the students' discussions and their social interactions within groups. Traditional gendered positions were reconstructed, for example with boys positioned as more competent in physics than girls. These positions were however also resisted and challenged.

Trends in breast reconstruction: Implications for the National Health Insurance Service

Directory of Open Access Journals (Sweden)

Ki Yong Hong

2018-05-01

Full Text Available Background Breast reconstruction has become more common as mastectomy has become more frequent. In Korea, the National Health Insurance Service (NHIS began covering breast reconstruction in April 2015. This study aimed to investigate trends in mastectomy and breast reconstruction over the past 10 years and to evaluate the impact of NHIS coverage on breast reconstruction. Methods Nationwide data regarding mastectomy and breast reconstruction were collected from the Korean Breast Cancer Society registry database. Multiple variables were analyzed in the records of patients who underwent breast reconstruction from January 2005 to March 2017 at a single institution. Results At Seoul National University Hospital, the total number of reconstruction cases increased 13-fold from 2005 to 2016. The proportion of immediate breast reconstruction (IBR cases out of all cases of total mastectomy increased from 4% in 2005 to 52.0% in 2016. The proportion of delayed breast reconstruction (DBR cases out of all cases of breast reconstruction and the overall number of DBR cases increased from 8.8% (20 cases in 2012 to 18.3% (76 cases in 2016. After NHIS coverage was initiated, the proportions of IBR and DBR showed statistically significant increases (P<0.05. Among the IBR cases, the percentage of prosthesis-based reconstructions increased significantly (P<0.05, but this trend was not found with DBR. Total mastectomy became significantly more common after the expansion of NHIS coverage (P<0.05. Conclusions Over the last decade, there has been an increase in mastectomy and breast reconstruction, and the pace of increase accelerated after the expansion of NHIS coverage. It is expected that breast reconstruction will be a routine option for patients with breast cancer under the NHIS.

Numerical analysis of residual stresses reconstruction for axisymmetric glass components

Science.gov (United States)

Tao, Bo; Xu, Shuang; Yao, Honghui

2018-01-01

A non-destructive measurement method for 3D stress state in a glass cylinder using photoelasticity has been analyzed by simulation in this research. Based on simulated stresses in a glass cylinder, intensity of the cylinder in a circular polariscope can be calculated by Jones calculus. Therefore, the isoclinic angle and optical retardation can be obtained by six steps phase shifting technique. Through the isoclinic angle and optical retardation, the magnitude and distribution of residual stresses inside the glass cylinder in cylindrical coordinate system can be reconstructed. Comparing the reconstructed stresses with numerical simulated stresses, the results verify this non-destructive method can be used to reconstruct the 3D stresses. However, there are some mismatches in axial stress, radial stress and circumferential stress.

Improved immediate breast reconstruction as a result of oncoplastic multidisciplinary meeting

Directory of Open Access Journals (Sweden)

El Gammal MM

2017-04-01

Full Text Available Mohsen M El Gammal,1 Maria Lim,1 Rajan Uppal,2 Richard Sainsbury1 1Department of Breast Surgery, Parapet Breast Centre, Frimley Health Foundation Trust, Windsor, 2Department of Plastic and Reconstructive Surgery, Wexham and Heatherwood Hospital, Frimley Health Foundation Trust, Slough, UK Introduction: The National Institute for Health and Clinical Excellence guidelines recommend that breast reconstruction should be available to all women undergoing mastectomy and discussed at the initial surgical consultation (2002, and updated 2009. The National Mastectomy and Breast Reconstruction Audit (2009 showed that 21% of mastectomy patients underwent immediate breast reconstruction (IBR and 11% had delayed breast reconstruction (DBR. Breast reconstruction has been shown to have a positive effect on quality of life postmastectomy. This retrospective study investigated the impact of the introduction of a dedicated oncoplastic multidisciplinary meeting (OP MDM on our unit’s breast reconstruction rate.Patients and methods: A retrospective analysis of 229 women who underwent mastectomy, of whom 81 (35% underwent breast reconstruction between April 2014 and March 2016. Data were analyzed before and after introduction of OP MDM in April 2015. Data on patient age, type of surgery (mastectomy only, mastectomy and reconstruction, timing of reconstruction (IBR, DBR, and type of reconstruction (implant, autologous were collected.Results: Between April 2015 and March 2016, following establishment of OP multidisciplinary team in April 2015, of the 120 patients who had mastectomy, 50 (42% underwent breast reconstruction with 78% (39/50 choosing IBR (56% implant reconstruction and 22% autologous. Compared to the period between April 2014 and March 2015 preceding the OP MDM, of 109 patients who underwent mastectomy, only 31 (28% had breast reconstruction with 64% (20/31 choosing IBR (45% implant reconstruction and 19% autologous. The rate of DBR was lower, 22% (11

Development of a North American paleoclimate pollen-based reconstruction database application

Science.gov (United States)

Ladd, Matthew; Mosher, Steven; Viau, Andre

2013-04-01

Recent efforts in synthesizing paleoclimate records across the globe has warranted an effort to standardize the different paleoclimate archives currently available in order to facilitate data-model comparisons and hence improve our estimates of future climate change. It is often the case that the methodology and programs make it challenging for other researchers to reproduce the results for a reconstruction, therefore there is a need for to standardize paleoclimate reconstruction databases in an application specific to proxy data. Here we present a methodology using the open source R language using North American pollen databases (e.g. NAPD, NEOTOMA) where this application can easily be used to perform new reconstructions and quickly analyze and output/plot the data. The application was developed to easily test methodological and spatial/temporal issues that might affect the reconstruction results. The application allows users to spend more time analyzing and interpreting results instead of on data management and processing. Some of the unique features of this R program are the two modules each with a menu making the user feel at ease with the program, the ability to use different pollen sums, select one of 70 climate variables available, substitute an appropriate modern climate dataset, a user-friendly regional target domain, temporal resolution criteria, linear interpolation and many other features for a thorough exploratory data analysis. The application program will be available for North American pollen-based reconstructions and eventually be made available as a package through the CRAN repository by late 2013.

Radiotherapy and breast reconstruction: complications and cosmesis with TRAM versus tissue expander/implant

International Nuclear Information System (INIS)

Chawla, Ashish K.; Kachnic, Lisa A.; Taghian, Alphonse G.; Niemierko, Andrzej; Zapton, Daniel T.; Powell, Simon N.

2002-01-01

Purpose: Radiotherapy (RT) has an important role in breast cancer treatment after modified radical mastectomy. Many of these patients also undergo breast reconstruction. We reviewed our institutions' experience to determine the outcome of patients treated with breast reconstruction and RT. Methods and Materials: Between 1981 and 1999, 48 breast cancer patients underwent modified radical mastectomy, breast reconstruction, and ipsilateral breast RT during their treatment course. Reconstruction either preceded or followed RT. Autologous reconstruction with a transverse rectus abdominus myocutaneous (TRAM) flap was performed in 30 patients, and 18 underwent expander and implant (E/I) reconstruction. The primary endpoint was the quality of the reconstructed, irradiated breast, as measured by analyzing the actuarial incidence of complications. The cosmetic outcome was also assessed by multidisciplinary review of the follow-up visits. Results: The median follow-up from reconstruction was 32 months. The actuarial 2-year complication rate was 53% for patients receiving E/I vs. 12% for those receiving TRAM reconstruction (p<0.01). No other patient or treatment-related factors had a significant impact on complications. The cosmetic outcome was also significantly better in the TRAM subgroup than in the E/I subgroup. Conclusion: The tolerance and cosmetic outcome of breast reconstruction for breast cancer patients in irradiated sites depends significantly on the type of reconstruction used

Analysis, reconstruction and manipulation using arterial snakes

KAUST Repository

Li, Guo

2010-01-01

Man-made objects often consist of detailed and interleaving structures, which are created using cane, coils, metal wires, rods, etc. The delicate structures, although manufactured using simple procedures, are challenging to scan and reconstruct. We observe that such structures are inherently 1D, and hence are naturally represented using an arrangement of generating curves. We refer to the resultant surfaces as arterial surfaces. In this paper we approach for analyzing, reconstructing, and manipulating such arterial surfaces. The core of the algorithm is a novel deformable model, called arterial snake, that simultaneously captures the topology and geometry of the arterial objects. The recovered snakes produce a natural decomposition of the raw scans, with the decomposed parts often capturing meaningful object sections. We demonstrate the robustness of our algorithm on a variety of arterial objects corrupted with noise, outliers, and with large parts missing. We present a range of applications including reconstruction, topology repairing, and manipulation of arterial surfaces by directly controlling the underlying curve network and the associated sectional profiles, which are otherwise challenging to perform. © 2010 ACM.

Noise propagation in iterative reconstruction algorithms with line searches

International Nuclear Information System (INIS)

Qi, Jinyi

2003-01-01

In this paper we analyze the propagation of noise in iterative image reconstruction algorithms. We derive theoretical expressions for the general form of preconditioned gradient algorithms with line searches. The results are applicable to a wide range of iterative reconstruction problems, such as emission tomography, transmission tomography, and image restoration. A unique contribution of this paper comparing to our previous work [1] is that the line search is explicitly modeled and we do not use the approximation that the gradient of the objective function is zero. As a result, the error in the estimate of noise at early iterations is significantly reduced

Model-based iterative reconstruction technique for radiation dose reduction in chest CT: comparison with the adaptive statistical iterative reconstruction technique

International Nuclear Information System (INIS)

Katsura, Masaki; Matsuda, Izuru; Akahane, Masaaki; Sato, Jiro; Akai, Hiroyuki; Yasaka, Koichiro; Kunimatsu, Akira; Ohtomo, Kuni

2012-01-01

To prospectively evaluate dose reduction and image quality characteristics of chest CT reconstructed with model-based iterative reconstruction (MBIR) compared with adaptive statistical iterative reconstruction (ASIR). One hundred patients underwent reference-dose and low-dose unenhanced chest CT with 64-row multidetector CT. Images were reconstructed with 50 % ASIR-filtered back projection blending (ASIR50) for reference-dose CT, and with ASIR50 and MBIR for low-dose CT. Two radiologists assessed the images in a blinded manner for subjective image noise, artefacts and diagnostic acceptability. Objective image noise was measured in the lung parenchyma. Data were analysed using the sign test and pair-wise Student's t-test. Compared with reference-dose CT, there was a 79.0 % decrease in dose-length product with low-dose CT. Low-dose MBIR images had significantly lower objective image noise (16.93 ± 3.00) than low-dose ASIR (49.24 ± 9.11, P < 0.01) and reference-dose ASIR images (24.93 ± 4.65, P < 0.01). Low-dose MBIR images were all diagnostically acceptable. Unique features of low-dose MBIR images included motion artefacts and pixellated blotchy appearances, which did not adversely affect diagnostic acceptability. Diagnostically acceptable chest CT images acquired with nearly 80 % less radiation can be obtained using MBIR. MBIR shows greater potential than ASIR for providing diagnostically acceptable low-dose CT images without severely compromising image quality. (orig.)

Japan's Fiscal Policy and Fiscal Reconstruction

OpenAIRE

Ihori, Toshihiro; Nakamoto, Atsushi

2005-01-01

This paper investigates the macroeconomic effects of fiscal policy and the fiscal reconstruction movement in Japan. We first summarize Japan's fiscal policy in recent years and discuss advantages and disadvantages of government deficits. Next, we investigate the macroeconomic effects of Japanese fiscal policy and evaluate the plausibility of non-Keynesian effects. We also analyze the possibility of the crowding-in effect of fiscal policy and investigate the spillover effects of deregulation. ...

PR-CALC: A Program for the Reconstruction of NMR Spectra from Projections

International Nuclear Information System (INIS)

Coggins, Brian E.; Zhou Pei

2006-01-01

Projection-reconstruction NMR (PR-NMR) has attracted growing attention as a method for collecting multidimensional NMR data rapidly. The PR-NMR procedure involves measuring lower-dimensional projections of a higher-dimensional spectrum, which are then used for the mathematical reconstruction of the full spectrum. We describe here the program PR-CALC, for the reconstruction of NMR spectra from projection data. This program implements a number of reconstruction algorithms, highly optimized to achieve maximal performance, and manages the reconstruction process automatically, producing either full spectra or subsets, such as regions or slices, as requested. The ability to obtain subsets allows large spectra to be analyzed by reconstructing and examining only those subsets containing peaks, offering considerable savings in processing time and storage space. PR-CALC is straightforward to use, and integrates directly into the conventional pipeline for data processing and analysis. It was written in standard C+ + and should run on any platform. The organization is flexible, and permits easy extension of capabilities, as well as reuse in new software. PR-CALC should facilitate the widespread utilization of PR-NMR in biomedical research

Pulmonary sequestration: diagnosis with three dimensional reconstruction using spiral CT

International Nuclear Information System (INIS)

Nie Yongkang; Zhao Shaohong; Cai Zulong; Yang Li; Zhao Hong; Zhang Ailian; Huang Hui

2003-01-01

Objective: To evaluate the role of three dimensional (3D) reconstruction using spiral CT in the diagnosis of pulmonary sequestration. Methods: Ten patients with pulmonary sequestration were analyzed. The diagnoses were confirmed by angiography in 2 patients, by operation in 2 patients, and by CT angiography in 6 patients. All patients were examined with Philips SR 7000 or GE Lightspeed Plus scanner. CT images were transferred to a workstation and 3D reconstruction was performed. All images were reviewed and analyzed by two radiologists. Results: Among 10 patients, the pulmonary sequestration was in the right lower lobe in 1 patient and in the left lower lobe in 9 patients. Anomalous systemic arteries originated from thoracic aorta in 8 patients and from celiac artery in 2 patients. On plain CT scan, there were 4 patients with patchy opacities, 3 patients with hilar mass accompanying vascular engorgement and profusion in adjacent parenchyma, 2 patients with finger-like appendage surrounded by hyper-inflated lung, and 1 patient with lung mass-like lesion. Enhanced CT revealed anomalous systemic arteries in 9 patients and drainage vein in 7 patients. Maximum intensity projection (MIP) and curvilinear reconstruction could depict the abnormal systemic artery and drainage vein in sequestration. Surface shadow display (SSD) and volume rendering (VR) could delineate the anomalous systemic artery. Conclusion: 3D reconstruction with enhanced spiral CT can depict anomalous systemic artery and drainage vein and it is the first method of choice in diagnosing pulmonary sequestration

The pedagogical value of Disassemble/Analyze/Assemble (DAA) activities: Assessing the potential for motivation and transfer

Science.gov (United States)

Dalrymple, Odesma Onika

Undergraduate engineering institutions are currently seeking to improve recruiting practices and to retain engineering majors particularly by addressing what many studies document as a major challenge of poor instruction. There is an undisputed need for instructional practices that motivate students in addition to facilitating the transfer of learning beyond the classroom. Reverse engineering and product dissection, more broadly termed Disassemble/Analyze/Assemble (DAA) activities, have shown potential to address these concerns, based on the reviews of students and professors alike. DAA activities involve the systematic deconstruction of an artifact, the subsequent analysis and possible reconstruction of its components for the purpose of understanding the embodied fundamental concepts, design principles and developmental processes. These activities have been part of regular industry practice for some time; however, the systematic analysis of their benefits for learning and instruction is a relatively recent phenomenon. A number of studies have provided highly descriptive accounts of curricula and possible outcomes of DAA activities; but, relatively few have compared participants doing DAA activities to a control group doing more traditional activities. In this respect, two quasi-experiments were conducted as part of a first-year engineering laboratory, and it was hypothesized that students who engaged in the DAA activity would be more motivated and would demonstrate higher frequencies of transfer than the control. A DAA activity that required students to disassemble a single-use camera and analyze its components to discover how it works was compared to a step-by-step laboratory activity in the first experiment and a lecture method of instruction in the second experiment. In both experiments, over forty percent of the students that engaged in the DAA activity demonstrated the ability to transfer the knowledge gained about the functions of the camera's components and

Facebook Facts: Breast Reconstruction Patient-Reported Outcomes Using Social Media.

Science.gov (United States)

Tang, Sherry Y Q; Israel, Jacqueline S; Poore, Samuel O; Afifi, Ahmed M

2018-05-01

Social media are used for information sharing among patients with similar health conditions, and analysis of social media activity could inform clinical decision-making. The aim of this study was to use Facebook to evaluate a cohort of individuals' perceptions of and satisfaction with breast reconstruction. In this observational study, the authors collected and analyzed posts pertaining to autologous and implant-based breast reconstruction from active Facebook groups. Patient satisfaction data were categorized, and a thematic analysis of posts was conducted. Qualitative posts were grouped based on common themes and quantitatively compared using frequency and chi-square analysis. The authors evaluated 500 posts from two Facebook groups. Two hundred sixty-four posts referenced deep inferior epigastric perforator (DIEP) flap reconstruction and 117 were related to implant-based reconstruction. Among individuals referencing DIEP flap reconstruction, 52 percent were satisfied, compared with 20 percent of individuals who referenced satisfaction with implant-based reconstruction (p < 0.0001). Individuals posting about DIEP flaps reported a higher rate of unexpected side effects (p < 0.001) and numbness (p = 0.004). When referencing implant-based reconstruction, individuals reported significantly higher rates of infection, contracture, and implant failure (p < 0.001). Based on the authors' review of social media activity, individuals undergoing DIEP flap breast reconstruction expressed relatively high individual satisfaction despite difficult postoperative recovery. Individuals who referenced implant-based reconstruction mentioned infection and implant failure, leading to high rates of dissatisfaction. Social media appear to provide informational and emotional support to patients. Plastic surgeons can use social media to gather unbiased information of patients' experience to inform clinical conversation and guide clinical practice.

Analyzing Student Performance and Attitudes toward Textual versus Iconic Programming Languages

Science.gov (United States)

Lin, Janet Mei-Chuen; Yang, Mei-Ching

2009-01-01

In this study half of 52 sixth graders learned to program in MSWLogo and the other half in Drape. An analysis of students' test scores revealed that Drape (an iconic language) seemed to have a steeper learning curve than MSWLogo (a textual language). However, as students gradually became more familiar with either language, the difference in…

Analyzing the Hidden Curriculum of Screen Media Advertising

Science.gov (United States)

Mason, Lance E.

2015-01-01

This media literacy article introduces a questioning framework for analyzing screen media with students and provides an example analysis of two contemporary commercials. Investigating screen conventions can help students understand the persuasive functions of commercials, as well as how the unique sensory experience of screen viewing affects how…

Reconstruction of Laser-Induced Surface Topography from Electron Backscatter Diffraction Patterns.

Science.gov (United States)

Callahan, Patrick G; Echlin, McLean P; Pollock, Tresa M; De Graef, Marc

2017-08-01

We demonstrate that the surface topography of a sample can be reconstructed from electron backscatter diffraction (EBSD) patterns collected with a commercial EBSD system. This technique combines the location of the maximum background intensity with a correction from Monte Carlo simulations to determine the local surface normals at each point in an EBSD scan. A surface height map is then reconstructed from the local surface normals. In this study, a Ni sample was machined with a femtosecond laser, which causes the formation of a laser-induced periodic surface structure (LIPSS). The topography of the LIPSS was analyzed using atomic force microscopy (AFM) and reconstructions from EBSD patterns collected at 5 and 20 kV. The LIPSS consisted of a combination of low frequency waviness due to curtaining and high frequency ridges. The morphology of the reconstructed low frequency waviness and high frequency ridges matched the AFM data. The reconstruction technique does not require any modification to existing EBSD systems and so can be particularly useful for measuring topography and its evolution during in situ experiments.

Trends in Revision Elbow Ulnar Collateral Ligament Reconstruction in Professional Baseball Pitchers.

Science.gov (United States)

Wilson, Alexander T; Pidgeon, Tyler S; Morrell, Nathan T; DaSilva, Manuel F

2015-11-01

To determine the frequency of revision elbow ulnar collateral ligament (UCL) reconstruction in professional baseball pitchers. Data were collected on 271 professional baseball pitchers who underwent primary UCL reconstruction. Each player was evaluated retrospectively for occurrence of revision UCL reconstructive surgery to treat failed primary reconstruction. Data on players who underwent revision UCL reconstruction were compiled to determine total surgical revision incidence and revision rate by year. The incidence of early revision was analyzed for trends. Average career length after primary UCL reconstruction was calculated and compared with that of players who underwent revision surgery. Logistic regression analysis was performed to assess risk factors for revision including handedness, pitching role, and age at the time of primary reconstruction. Between 1974 and 2014, the annual incidence of primary UCL reconstructions among professional pitchers increased, while the proportion of cases being revised per year decreased. Of the 271 pitchers included in the study, 40 (15%) required at least 1 revision procedure during their playing career. Three cases required a second UCL revision reconstruction. The average time from primary surgery to revision was 5.2 ± 3.2 years (range, 1-13 years). The average length of career following primary reconstruction for all players was 4.9 ± 4.3 years (range, 0-22 years). The average length of career following revision UCL reconstruction was 2.5 ± 2.4 years (range, 0-8 years). No risk factors for needing revision UCL reconstruction were identified. The incidence of primary UCL reconstructions among professional pitchers is increasing; however, the rate of primary reconstructions requiring revision is decreasing. Explanations for the decreased revision rate may include improved surgical technique and improved rehabilitation protocols. Therapeutic IV. Copyright © 2015 American Society for Surgery of the Hand. Published by

Patellofemoral Pressure Changes After Static and Dynamic Medial Patellofemoral Ligament Reconstructions.

Science.gov (United States)

Rood, Akkie; Hannink, Gerjon; Lenting, Anke; Groenen, Karlijn; Koëter, Sander; Verdonschot, Nico; van Kampen, Albert

2015-10-01

Reconstructing the medial patellofemoral ligament (MPFL) has become a key procedure for stabilizing the patella. Different techniques to reconstruct the MPFL have been described: static techniques in which the graft is fixed rigidly to the bone or dynamic techniques with soft tissue fixation. Static MPFL reconstruction is most commonly used. However, dynamic reconstruction deforms more easily and presumably functions more like the native MPFL. The aim of the study was to evaluate the effect of the different MPFL fixation techniques on patellofemoral pressures compared with the native situation. The hypothesis was that dynamic reconstruction would result in patellofemoral pressures closer to those generated in an intact knee. Controlled laboratory study. Seven fresh-frozen knee specimens were tested in an in vitro knee joint loading apparatus. Tekscan pressure-sensitive films fixed to the retropatellar cartilage measured mean patellofemoral and peak pressures, contact area, and location of the center of force (COF) at fixed flexion angles from 0° to 110°. Four different conditions were tested: intact, dynamic, partial dynamic, and static MPFL reconstruction. Data were analyzed using linear mixed models. Static MPFL reconstruction resulted in higher peak and mean pressures from 60° to 110° of flexion (P .05). The COF in the static reconstruction group moved more medially on the patella from 50° to 110° of flexion compared with the other conditions. The contact area showed no significant differences between the test conditions. After static MPFL reconstruction, the patellofemoral pressures in flexion angles from 60° to 110° were 3 to 5 times higher than those in the intact situation. The pressures after dynamic MPFL reconstruction were similar as compared with those in the intact situation, and therefore, dynamic MPFL reconstruction could be a safer option than static reconstruction for stabilizing the patella. This study showed that static MPFL reconstruction

Breast reconstruction after mastectomy

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Daniel eSchmauss

2016-01-01

Full Text Available Breast cancer is the leading cause of cancer death in women worldwide. Its surgical approach has become less and less mutilating in the last decades. However, the overall number of breast reconstructions has significantly increased lately. Nowadays breast reconstruction should be individualized at its best, first of all taking into consideration oncological aspects of the tumor, neo-/adjuvant treatment and genetic predisposition, but also its timing (immediate versus delayed breast reconstruction, as well as the patient’s condition and wish. This article gives an overview over the various possibilities of breast reconstruction, including implant- and expander-based reconstruction, flap-based reconstruction (vascularized autologous tissue, the combination of implant and flap, reconstruction using non-vascularized autologous fat, as well as refinement surgery after breast reconstruction.

Breast reconstruction - implants

Science.gov (United States)

Breast implants surgery; Mastectomy - breast reconstruction with implants; Breast cancer - breast reconstruction with implants ... harder to find a tumor if your breast cancer comes back. Getting breast implants does not take as long as breast reconstruction ...

Analyzing International Letters in a Business Communication Class.

Science.gov (United States)

Devet, Bonnie

1998-01-01

Shows how students can use persuasive principles of communication (format and writer's purpose) and of classical rhetoric (organization, ethos, pathos, logos, and style) to improve their ability to analyze business letters. Shows how applying these principles to the analysis of business letters from other countries helps students write better and…

Adaptive algebraic reconstruction technique

International Nuclear Information System (INIS)

Lu Wenkai; Yin Fangfang

2004-01-01

Algebraic reconstruction techniques (ART) are iterative procedures for reconstructing objects from their projections. It is proven that ART can be computationally efficient by carefully arranging the order in which the collected data are accessed during the reconstruction procedure and adaptively adjusting the relaxation parameters. In this paper, an adaptive algebraic reconstruction technique (AART), which adopts the same projection access scheme in multilevel scheme algebraic reconstruction technique (MLS-ART), is proposed. By introducing adaptive adjustment of the relaxation parameters during the reconstruction procedure, one-iteration AART can produce reconstructions with better quality, in comparison with one-iteration MLS-ART. Furthermore, AART outperforms MLS-ART with improved computational efficiency

Analyzing the Existing Undergraduate Engineering Leadership Skills

OpenAIRE

Hamed M. Almalki; Luis Rabelo; Charles Davis; Hammad Usmani; Debra Hollister; Alfonso Sarmiento

2016-01-01

Purpose: Studying and analyzing the undergraduate engineering students' leadership skills to discover their potential leadership strengths and weaknesses. This study will unveil potential ways to enhance the ways we teach engineering leadership. The research has great insights that might assist engineering programs to improve curricula for the purpose of better engineering preparation to meet industry's demands. Methodology and Findings: 441 undergraduate engineering students have been s...

[Qilin Pills for obstructive azoospermia after ejaculatory duct reconstruction].

Science.gov (United States)

Zhang, Lei; Gao, Ping; Ren, Fei-Qiang; Chang, De-Gui; Yu, Xu-Jun; Zhang, Pei-Hai

2016-09-01

To observe the clinical effect of Qilin Pills in the treatment of severe oligozoospermia after microsurgical ejaculatory duct reconstruction for obstructive azoospermia. We retrospectively analyzed 75 cases of obstructive azoospermia treated by ejaculatory duct reconstruction followed by administration of Qilin Pills. The patients were divided into a Qilin group (n=42) and a control group (n=33) postoperatively, treated with Qilin Pills and placebo, respectively. After 3 months of medication, we compared the sperm quality between the two groups of patients. After 3 months' treatment, all the patients experienced remarkable improvement in sperm quality (P0.05). The total effectiveness rate was higher in the Qilin group than in the controls (88.1% vs 72.7%), but with no significant difference between the two groups (P>0.05). Qilin Pills are fairly effective in improving the quantity of sperm in obstructive azoospermia patients after ejaculatory duct reconstruction.

Plastic surgery in chest wall reconstruction: relevant aspects - case series

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Diogo Franco

Full Text Available Objective: to discuss the participation of Plastic Surgery in the reconstruction of the chest wall, highlighting relevant aspects of interdisciplinaryness. Methods: we analyzed charts from 20 patients who underwent extensive resection of the thoracic integument, between 2000 and 2014, recording the indication of resection, the extent and depth of the raw areas, types of reconstructions performed and complications. Results: among the 20 patients, averaging 55 years old, five were males and 15 females. They resections were: one squamous cell carcinoma, two basal cell carcinomas, five chondrosarcomas and 12 breast tumors. The extent of the bloody areas ranged from 4x9 cm to 25x40 cm. In 12 patients the resection included the muscular plane. In the remaining eight, the tumor removal achieved a total wall thickness. For reconstruction we used: one muscular flap associated with skin grafting, nine flaps and ten regional fasciocutaneous flaps. Two patients undergoing reconstruction with fasciocutaneous flaps had partially suffering of the flap, solved with employment of a myocutaneous flap. The other patients displayed no complications with the techniques used, requiring only one surgery. Conclusion: the proper assessment of local tissues and flaps available for reconstruction, in addition to the successful integration of Plastic Surgery with the specialties involved in the treatment, enable extensive resections of the chest wall and reconstructions that provide patient recovery.

Iterative reconstruction of magnetic induction using Lorentz transmission electron tomography

International Nuclear Information System (INIS)

Phatak, C.; Gürsoy, D.

2015-01-01

Intense ongoing research on complex nanomagnetic structures requires a fundamental understanding of the 3D magnetization and the stray fields around the nano-objects. 3D visualization of such fields offers the best way to achieve this. Lorentz transmission electron microscopy provides a suitable combination of high resolution and ability to quantitatively visualize the magnetization vectors using phase retrieval methods. In this paper, we present a formalism to represent the magnetic phase shift of electrons as a Radon transform of the magnetic induction of the sample. Using this formalism, we then present the application of common tomographic methods particularly the iterative methods, to reconstruct the 3D components of the vector field. We present an analysis of the effect of missing wedge and the limited angular sampling as well as reconstruction of complex 3D magnetization in a nanowire using simulations. - Highlights: • We present a formalism to represent electron-optical magnetic phase shift as a Radon transform of the 3D magnetic induction of the nano-object. • We have analyzed four different tomographic reconstruction methods for vectorial data reconstruction. • Reconstruction methods were tested for varying experimental limitations such as limited tilt range and limited angular sampling. • The analysis showed that Gridrec and SIRT methods performed better with lower errors than other reconstruction methods

Reconstructing Northeastern United States temperatures using Atlantic white cedar tree rings

Science.gov (United States)

Pearl, Jessie K.; Anchukaitis, Kevin J.; Pederson, Neil; Donnelly, Jeffrey P.

2017-11-01

Our knowledge of climate variability in the densely populated Northeastern United States is limited to instrumental data of the last century. Most regional paleoclimate proxies reflect a mix of climate responses, which makes reconstructing historical climate a challenge. Here we analyze tree-ring chronologies from Atlantic white cedar (Chamaecyparis thyoides) as a potential regional paleotemperature proxy. We evaluate our tree-ring network for spatiotemporal climate signal strength and reconstruction skill across New England. Atlantic white cedar sites in the northern section of the species’ range exhibit positive significant annual growth relationships with local and regional temperatures. Chronologies constructed from northern sites yield skillful reconstructions of temperature that reproduce centennial, multidecadal, and interannual variability in the instrumental record, providing a novel paleotemperature record for New England.

Nature of science in instruction materials of science through the model of educational reconstruction

Science.gov (United States)

Azizah, Nur; Mudzakir, Ahmad

2016-02-01

The study was carried out to reconstruct the science teaching materials charged view of the nature of science (VNOS). This reconstruction process using the Model of Educational Reconstruction (MER), which is the framework for research and development of science education as well as a guide for planning the teaching of science in the schools is limited in two stages, namely: content structure analysis, and empirical studies of learners. The purpose of this study is to obtain a pre-conception of learners and prospective scientists to the topic of the nature of the material and utilization. The method used to descriptive with the instruments is guidelines for interviews for 15 students of class VIII, text analysis sheet, sheet analysis of the concept, and the validation sheet indicators and learning objectives NOS charged on cognitive and affective aspects. The results obtained in the form of pre-conceptions of learners who demonstrate almost 100% of students know the types of materials and some of its nature, the results of the scientist's perspective on the topic of the nature of the material and its use, as well as the results of the validation indicators and learning objectives charged NOS and competencies PISA 2015 cognitive and affective aspects with CVI value of 0.99 and 1.0 after being validated by five experts. This suggests that the indicators and the resulting learning objectives feasible and can proceed to the reconstruction of teaching materials on the topic of material properties and utilization.

Segmentation, Reconstruction, and Analysis of Blood Thrombus Formation in 3D 2-Photon Microscopy Images

Directory of Open Access Journals (Sweden)

Xu Zhiliang

2010-01-01

Full Text Available We study the problem of segmenting, reconstructing, and analyzing the structure growth of thrombi (clots in blood vessels in vivo based on 2-photon microscopic image data. First, we develop an algorithm for segmenting clots in 3D microscopic images based on density-based clustering and methods for dealing with imaging artifacts. Next, we apply the union-of-balls (or alpha-shape algorithm to reconstruct the boundary of clots in 3D. Finally, we perform experimental studies and analysis on the reconstructed clots and obtain quantitative data of thrombus growth and structures. We conduct experiments on laser-induced injuries in vessels of two types of mice (the wild type and the type with low levels of coagulation factor VII and analyze and compare the developing clot structures based on their reconstructed clots from image data. The results we obtain are of biomedical significance. Our quantitative analysis of the clot composition leads to better understanding of the thrombus development, and is valuable to the modeling and verification of computational simulation of thrombogenesis.

Patients' Aesthetic Concerns After Horizontally Placed Abdominal Free Flap Breast Reconstruction.

Science.gov (United States)

Kim, Eun Key; Suh, Young Chul; Maldonado, Andrés A; Yun, Jiyoung; Lee, Taik Jong

2015-10-01

The present study aimed to analyze patients' aesthetic concerns after breast reconstruction with abdominal free flap by reporting secondary cosmetic procedures performed based on the patients' request, and analyzed the effect of adjuvant therapies and other variables on such outcomes. All patients who underwent unilateral immediate reconstruction were enrolled prospectively. Free abdominal flaps were placed horizontally with little manipulation. Secondary procedures were actively recommended during the follow-up period to meet the patients' aesthetic concerns. The numbers and types of the secondary procedures and the effects of various factors were analyzed. 150 patients met the eligibility criteria. The average number of overall secondary surgeries per patient was 1.25. Patients with skin-sparing mastectomy required significantly higher number of secondary surgeries compared with those who underwent nipple-areolar skin-sparing mastectomy. When confined to the cosmetic procedures, 58 (38.7 %) patients underwent 75 operations. The most common procedures were flank dog ear revision, fat injection of the reconstructed breast, and breast liposuction. None of the radiated patients underwent liposuction of the flap. Most commonly liposuctioned regions were the central-lateral and lower-lateral, while fat was most commonly injected to the upper-medial and upper-central part of the breast. The present study delineated the numbers and types of the secondary operations after horizontally placed abdominal free flap transfer with analysis of the influence of various factors. Addressing such issues during the primary reconstruction would help to reduce the need and extent of the secondary operations and to maximize aesthetic outcome. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Low-Cost 3D Printing Orbital Implant Templates in Secondary Orbital Reconstructions.

Science.gov (United States)

Callahan, Alison B; Campbell, Ashley A; Petris, Carisa; Kazim, Michael

Despite its increasing use in craniofacial reconstructions, three-dimensional (3D) printing of customized orbital implants has not been widely adopted. Limitations include the cost of 3D printers able to print in a biocompatible material suitable for implantation in the orbit and the breadth of available implant materials. The authors report the technique of low-cost 3D printing of orbital implant templates used in complex, often secondary, orbital reconstructions. A retrospective case series of 5 orbital reconstructions utilizing a technique of 3D printed orbital implant templates is presented. Each patient's Digital Imaging and Communications in Medicine data were uploaded and processed to create 3D renderings upon which a customized implant was designed and sent electronically to printers open for student use at our affiliated institutions. The mock implants were sterilized and used intraoperatively as a stencil and mold. The final implant material was chosen by the surgeons based on the requirements of the case. Five orbital reconstructions were performed with this technique: 3 tumor reconstructions and 2 orbital fractures. Four of the 5 cases were secondary reconstructions. Molded Medpor Titan (Stryker, Kalamazoo, MI) implants were used in 4 cases and titanium mesh in 1 case. The stenciled and molded implants were adjusted no more than 2 times before anchored in place (mean 1). No case underwent further revision. The technique and cases presented demonstrate 1) the feasibility and accessibility of low-cost, independent use of 3D printing technology to fashion patient-specific implants in orbital reconstructions, 2) the ability to apply this technology to the surgeon's preference of any routinely implantable material, and 3) the utility of this technique in complex, secondary reconstructions.

Reconstructed phase spaces of intrinsic mode functions. Application to postural stability analysis.

Science.gov (United States)

Snoussi, Hichem; Amoud, Hassan; Doussot, Michel; Hewson, David; Duchêne, Jacques

2006-01-01

In this contribution, we propose an efficient nonlinear analysis method characterizing postural steadiness. The analyzed signal is the displacement of the centre of pressure (COP) collected from a force plate used for measuring postural sway. The proposed method consists of analyzing the nonlinear dynamics of the intrinsic mode functions (IMF) of the COP signal. The nonlinear properties are assessed through the reconstructed phase spaces of the different IMFs. This study shows some specific geometries of the attractors of some intrinsic modes. Moreover, the volume spanned by the geometric attractors in the reconstructed phase space represents an efficient indicator of the postural stability of the subject. Experiments results corroborate the effectiveness of the method to blindly discriminate young subjects, elderly subjects and subjects presenting a risk of falling.

Analysis on the reconstruction accuracy of the Fitch method for inferring ancestral states

Directory of Open Access Journals (Sweden)

Grünewald Stefan

2011-01-01

Full Text Available Abstract Background As one of the most widely used parsimony methods for ancestral reconstruction, the Fitch method minimizes the total number of hypothetical substitutions along all branches of a tree to explain the evolution of a character. Due to the extensive usage of this method, it has become a scientific endeavor in recent years to study the reconstruction accuracies of the Fitch method. However, most studies are restricted to 2-state evolutionary models and a study for higher-state models is needed since DNA sequences take the format of 4-state series and protein sequences even have 20 states. Results In this paper, the ambiguous and unambiguous reconstruction accuracy of the Fitch method are studied for N-state evolutionary models. Given an arbitrary phylogenetic tree, a recurrence system is first presented to calculate iteratively the two accuracies. As complete binary tree and comb-shaped tree are the two extremal evolutionary tree topologies according to balance, we focus on the reconstruction accuracies on these two topologies and analyze their asymptotic properties. Then, 1000 Yule trees with 1024 leaves are generated and analyzed to simulate real evolutionary scenarios. It is known that more taxa not necessarily increase the reconstruction accuracies under 2-state models. The result under N-state models is also tested. Conclusions In a large tree with many leaves, the reconstruction accuracies of using all taxa are sometimes less than those of using a leaf subset under N-state models. For complete binary trees, there always exists an equilibrium interval [a, b] of conservation probability, in which the limiting ambiguous reconstruction accuracy equals to the probability of randomly picking a state. The value b decreases with the increase of the number of states, and it seems to converge. When the conservation probability is greater than b, the reconstruction accuracies of the Fitch method increase rapidly. The reconstruction

Smoothing expansion rate data to reconstruct cosmological matter perturbations

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, J.E.; Alcaniz, J.S.; Carvalho, J.C., E-mail: javierernesto@on.br, E-mail: alcaniz@on.br, E-mail: jcarvalho@on.br [Departamento de Astronomia, Observatório Nacional, Rua Gal. José Cristino, 77, Rio de Janeiro, RJ 20921-400 (Brazil)

2017-08-01

The existing degeneracy between different dark energy and modified gravity cosmologies at the background level may be broken by analyzing quantities at the perturbative level. In this work, we apply a non-parametric smoothing (NPS) method to reconstruct the expansion history of the Universe ( H ( z )) from model-independent cosmic chronometers and high- z quasar data. Assuming a homogeneous and isotropic flat universe and general relativity (GR) as the gravity theory, we calculate the non-relativistic matter perturbations in the linear regime using the H ( z ) reconstruction and realistic values of Ω {sub m} {sub 0} and σ{sub 8} from Planck and WMAP-9 collaborations. We find a good agreement between the measurements of the growth rate and f σ{sub 8}( z ) from current large-scale structure observations and the estimates obtained from the reconstruction of the cosmic expansion history. Considering a recently proposed null test for GR using matter perturbations, we also apply the NPS method to reconstruct f σ{sub 8}( z ). For this case, we find a ∼ 3σ tension (good agreement) with the standard relativistic cosmology when the Planck (WMAP-9) priors are used.

Smoothing expansion rate data to reconstruct cosmological matter perturbations

International Nuclear Information System (INIS)

Gonzalez, J.E.; Alcaniz, J.S.; Carvalho, J.C.

2017-01-01

The existing degeneracy between different dark energy and modified gravity cosmologies at the background level may be broken by analyzing quantities at the perturbative level. In this work, we apply a non-parametric smoothing (NPS) method to reconstruct the expansion history of the Universe ( H ( z )) from model-independent cosmic chronometers and high- z quasar data. Assuming a homogeneous and isotropic flat universe and general relativity (GR) as the gravity theory, we calculate the non-relativistic matter perturbations in the linear regime using the H ( z ) reconstruction and realistic values of Ω m 0 and σ 8 from Planck and WMAP-9 collaborations. We find a good agreement between the measurements of the growth rate and f σ 8 ( z ) from current large-scale structure observations and the estimates obtained from the reconstruction of the cosmic expansion history. Considering a recently proposed null test for GR using matter perturbations, we also apply the NPS method to reconstruct f σ 8 ( z ). For this case, we find a ∼ 3σ tension (good agreement) with the standard relativistic cosmology when the Planck (WMAP-9) priors are used.

D Reconstruction and Visualization of Cultural Heritage: Analyzing Our Legacy Through Time

Science.gov (United States)

Rodríguez-Gonzálvez, P.; Muñoz-Nieto, A. L.; del Pozo, S.; Sanchez-Aparicio, L. J.; Gonzalez-Aguilera, D.; Micoli, L.; Gonizzi Barsanti, S.; Guidi, G.; Mills, J.; Fieber, K.; Haynes, I.; Hejmanowska, B.

2017-02-01

Temporal analyses and multi-temporal 3D reconstruction are fundamental for the preservation and maintenance of all forms of Cultural Heritage (CH) and are the basis for decisions related to interventions and promotion. Introducing the fourth dimension of time into three-dimensional geometric modelling of real data allows the creation of a multi-temporal representation of a site. In this way, scholars from various disciplines (surveyors, geologists, archaeologists, architects, philologists, etc.) are provided with a new set of tools and working methods to support the study of the evolution of heritage sites, both to develop hypotheses about the past and to model likely future developments. The capacity to "see" the dynamic evolution of CH assets across different spatial scales (e.g. building, site, city or territory) compressed in diachronic model, affords the possibility to better understand the present status of CH according to its history. However, there are numerous challenges in order to carry out 4D modelling and the requisite multi-data source integration. It is necessary to identify the specifications, needs and requirements of the CH community to understand the required levels of 4D model information. In this way, it is possible to determine the optimum material and technologies to be utilised at different CH scales, as well as the data management and visualization requirements. This manuscript aims to provide a comprehensive approach for CH time-varying representations, analysis and visualization across different working scales and environments: rural landscape, urban landscape and architectural scales. Within this aim, the different available metric data sources are systemized and evaluated in terms of their suitability.

Reconstruction of the democratic experience: democracy as a pedagogical belief in Dewey’s philosophy

Directory of Open Access Journals (Sweden)

Carina Tonieto

2012-06-01

Full Text Available The present article aims at reconstructing and analyzing the reasons that led the American educator John Dewey to elect democracy as the pedagogical belief of his educational philosophy. In order to do so, fi rstly our work will briefl y retrace the origins of democracy at the Greek paideia, in order to analyze the reasons that led Deweyto choose democracy as the main reference of his pedagogical belief. Finally, we will discuss the democratic concept of education on Dewey’s work Democracy and Education and the reasons why the author uses science, philosophy, and education as instruments of reconstruction of the democracy.

Deep Learning Methods for Particle Reconstruction in the HGCal

CERN Document Server

Arzi, Ofir

2017-01-01

The High Granularity end-cap Calorimeter is part of the phase-2 CMS upgrade (see Figure \\ref{fig:cms})\\cite{Contardo:2020886}. It's goal it to provide measurements of high resolution in time, space and energy. Given such measurements, the purpose of this work is to discuss the use of Deep Neural Networks for the task of particle and trajectory reconstruction, identification and energy estimation, during my participation in the CERN Summer Students Program.

Deep Learning Methods for Particle Reconstruction in the HGCal

CERN Document Server

Arzi, Ofir

2017-01-01

The High Granularity end-cap Calorimeter is part of the phase-2 CMS upgrade (see Figure 1)[1]. It’s goal it to provide measurements of high resolution in time, space and energy. Given such measurements, the purpose of this work is to discuss the use of Deep Neural Networks for the task of particle and trajectory reconstruction, identification and energy estimation, during my participation in the CERN Summer Students Program.

Computed Tomography Image Quality Evaluation of a New Iterative Reconstruction Algorithm in the Abdomen (Adaptive Statistical Iterative Reconstruction-V) a Comparison With Model-Based Iterative Reconstruction, Adaptive Statistical Iterative Reconstruction, and Filtered Back Projection Reconstructions.

Science.gov (United States)

Goodenberger, Martin H; Wagner-Bartak, Nicolaus A; Gupta, Shiva; Liu, Xinming; Yap, Ramon Q; Sun, Jia; Tamm, Eric P; Jensen, Corey T

The purpose of this study was to compare abdominopelvic computed tomography images reconstructed with adaptive statistical iterative reconstruction-V (ASIR-V) with model-based iterative reconstruction (Veo 3.0), ASIR, and filtered back projection (FBP). Abdominopelvic computed tomography scans for 36 patients (26 males and 10 females) were reconstructed using FBP, ASIR (80%), Veo 3.0, and ASIR-V (30%, 60%, 90%). Mean ± SD patient age was 32 ± 10 years with mean ± SD body mass index of 26.9 ± 4.4 kg/m. Images were reviewed by 2 independent readers in a blinded, randomized fashion. Hounsfield unit, noise, and contrast-to-noise ratio (CNR) values were calculated for each reconstruction algorithm for further comparison. Phantom evaluation of low-contrast detectability (LCD) and high-contrast resolution was performed. Adaptive statistical iterative reconstruction-V 30%, ASIR-V 60%, and ASIR 80% were generally superior qualitatively compared with ASIR-V 90%, Veo 3.0, and FBP (P ASIR-V 60% with respective CNR values of 5.54 ± 2.39, 8.78 ± 3.15, and 3.49 ± 1.77 (P ASIR 80% had the best and worst spatial resolution, respectively. Adaptive statistical iterative reconstruction-V 30% and ASIR-V 60% provided the best combination of qualitative and quantitative performance. Adaptive statistical iterative reconstruction 80% was equivalent qualitatively, but demonstrated inferior spatial resolution and LCD.

Bayesian signal reconstruction for 1-bit compressed sensing

International Nuclear Information System (INIS)

Xu, Yingying; Kabashima, Yoshiyuki; Zdeborová, Lenka

2014-01-01

The 1-bit compressed sensing framework enables the recovery of a sparse vector x from the sign information of each entry of its linear transformation. Discarding the amplitude information can significantly reduce the amount of data, which is highly beneficial in practical applications. In this paper, we present a Bayesian approach to signal reconstruction for 1-bit compressed sensing and analyze its typical performance using statistical mechanics. As a basic setup, we consider the case that the measuring matrix Φ has i.i.d entries and the measurements y are noiseless. Utilizing the replica method, we show that the Bayesian approach enables better reconstruction than the l 1 -norm minimization approach, asymptotically saturating the performance obtained when the non-zero entry positions of the signal are known, for signals whose non-zero entries follow zero mean Gaussian distributions. We also test a message passing algorithm for signal reconstruction on the basis of belief propagation. The results of numerical experiments are consistent with those of the theoretical analysis. (paper)

System and method for image reconstruction, analysis, and/or de-noising

KAUST Repository

Laleg-Kirati, Taous-Meriem

2015-11-12

A method and system can analyze, reconstruct, and/or denoise an image. The method and system can include interpreting a signal as a potential of a Schrödinger operator, decomposing the signal into squared eigenfunctions, reducing a design parameter of the Schrödinger operator, analyzing discrete spectra of the Schrödinger operator and combining the analysis of the discrete spectra to construct the image.

Analyzing public health policy: three approaches.

Science.gov (United States)

Coveney, John

2010-07-01

Policy is an important feature of public and private organizations. Within the field of health as a policy arena, public health has emerged in which policy is vital to decision making and the deployment of resources. Public health practitioners and students need to be able to analyze public health policy, yet many feel daunted by the subject's complexity. This article discusses three approaches that simplify policy analysis: Bacchi's "What's the problem?" approach examines the way that policy represents problems. Colebatch's governmentality approach provides a way of analyzing the implementation of policy. Bridgman and Davis's policy cycle allows for an appraisal of public policy development. Each approach provides an analytical framework from which to rigorously study policy. Practitioners and students of public health gain much in engaging with the politicized nature of policy, and a simple approach to policy analysis can greatly assist one's understanding and involvement in policy work.

Titan Density Reconstruction Using Radiometric and Cassini Attitude Control Flight Data

Science.gov (United States)

Andrade, Luis G., Jr.; Burk, Thomas A.

2015-01-01

This paper compares three different methods of Titan atmospheric density reconstruction for the Titan 87 Cassini flyby. T87 was a unique flyby that provided independent Doppler radiometric measurements on the ground throughout the flyby including at Titan closest approach. At the same time, the onboard accelerometer provided an independent estimate of atmospheric drag force and density during the flyby. These results are compared with the normal method of reconstructing atmospheric density using thruster on-time and angular momentum accumulation. Differences between the estimates are analyzed and a possible explanation for the differences is evaluated.

Little Ice Age climate reconstruction from ensemble reanalysis of Alpine glacier fluctuations

Directory of Open Access Journals (Sweden)

M. P. Lüthi

2014-04-01

Full Text Available Mountain glaciers sample a combination of climate fields – temperature, precipitation and radiation – by accumulation and melting of ice. Flow dynamics acts as a transfer function that maps volume changes to a length response of the glacier terminus. Long histories of terminus positions have been assembled for several glaciers in the Alps. Here I analyze terminus position histories from an ensemble of seven glaciers in the Alps with a macroscopic model of glacier dynamics to derive a history of glacier equilibrium line altitude (ELA for the time span 400–2010 C.E. The resulting climatic reconstruction depends only on records of glacier variations. The reconstructed ELA history is similar to recent reconstructions of Alpine summer temperature and Atlantic Multidecadal Oscillation (AMO index, but bears little resemblance to reconstructed precipitation variations. Most reconstructed low-ELA periods coincide with large explosive volcano eruptions, hinting at a direct effect of volcanic radiative cooling on mass balance. The glacier advances during the LIA, and the retreat after 1860, can thus be mainly attributed to temperature and volcanic radiative cooling.

Use of silicone implants in reconstructive plastic surgery for breast cancer

Directory of Open Access Journals (Sweden)

D. D. Pak

2012-01-01

Full Text Available The paper considers procedures for reconstructive plastic operations, by using silicone implants, in patients with breast cancer. It analyzes 592 primary breast repairs and evaluates their aesthetic effects and complications. The surgical procedures are described.

Analyzing force concept inventory with item response theory

Science.gov (United States)

Wang, Jing; Bao, Lei

2010-10-01

Item response theory is a popular assessment method used in education. It rests on the assumption of a probability framework that relates students' innate ability and their performance on test questions. Item response theory transforms students' raw test scores into a scaled proficiency score, which can be used to compare results obtained with different test questions. The scaled score also addresses the issues of ceiling effects and guessing, which commonly exist in quantitative assessment. We used item response theory to analyze the force concept inventory (FCI). Our results show that item response theory can be useful for analyzing physics concept surveys such as the FCI and produces results about the individual questions and student performance that are beyond the capability of classical statistics. The theory yields detailed measurement parameters regarding the difficulty, discrimination features, and probability of correct guess for each of the FCI questions.

Tomographic reconstruction of melanin structures of optical coherence tomography via the finite-difference time-domain simulation

Science.gov (United States)

Huang, Shi-Hao; Wang, Shiang-Jiu; Tseng, Snow H.

2015-03-01

Optical coherence tomography (OCT) provides high resolution, cross-sectional image of internal microstructure of biological tissue. We use the Finite-Difference Time-Domain method (FDTD) to analyze the data acquired by OCT, which can help us reconstruct the refractive index of the biological tissue. We calculate the refractive index tomography and try to match the simulation with the data acquired by OCT. Specifically, we try to reconstruct the structure of melanin, which has complex refractive indices and is the key component of human pigment system. The results indicate that better reconstruction can be achieved for homogenous sample, whereas the reconstruction is degraded for samples with fine structure or with complex interface. Simulation reconstruction shows structures of the Melanin that may be useful for biomedical optics applications.

GRAPPA reconstructed wave-CAIPI MP-RAGE at 7 Tesla.

Science.gov (United States)

Schwarz, Jolanda M; Pracht, Eberhard D; Brenner, Daniel; Reuter, Martin; Stöcker, Tony

2018-04-16

The aim of this project was to develop a GRAPPA-based reconstruction for wave-CAIPI data. Wave-CAIPI fully exploits the 3D coil sensitivity variations by combining corkscrew k-space trajectories with CAIPIRINHA sampling. It reduces artifacts and limits reconstruction induced spatially varying noise enhancement. The GRAPPA-based wave-CAIPI method is robust and does not depend on the accuracy of coil sensitivity estimations. We developed a GRAPPA-based, noniterative wave-CAIPI reconstruction algorithm utilizing multiple GRAPPA kernels. For data acquisition, we implemented a fast 3D magnetization-prepared rapid gradient-echo wave-CAIPI sequence tailored for ultra-high field application. The imaging results were evaluated by comparing the g-factor and the root mean square error to Cartesian CAIPIRINHA acquisitions. Additionally, to assess the performance of subcortical segmentations (calculated by FreeSurfer), the data were analyzed across five subjects. Sixteen-fold accelerated whole brain magnetization-prepared rapid gradient-echo data (1 mm isotropic resolution) were acquired in 40 seconds at 7T. A clear improvement in image quality compared to Cartesian CAIPIRINHA sampling was observed. For the chosen imaging protocol, the results of 16-fold accelerated wave-CAIPI acquisitions were comparable to results of 12-fold accelerated Cartesian CAIPIRINHA. In comparison to the originally proposed SENSitivity Encoding reconstruction of Wave-CAIPI data, the GRAPPA approach provided similar image quality. High-quality, wave-CAIPI magnetization-prepared rapid gradient-echo images can be reconstructed by means of a GRAPPA-based reconstruction algorithm. Even for high acceleration factors, the noniterative reconstruction is robust and does not require coil sensitivity estimations. By altering the aliasing pattern, ultra-fast whole-brain structural imaging becomes feasible. © 2018 International Society for Magnetic Resonance in Medicine.

Analyzing Student Teacher Critical Thinking through Blogs in an Electronic Community of Practice

Science.gov (United States)

Clark, Taylorann K.; Paulsen, Thomas H.

2016-01-01

Technology is becoming increasingly popular in higher education in the way students are asked to communicate and collaborate. The student teaching experience is an integral part of developing critical thinking skills in pre-service teachers. During this experience, it is important that student teachers practice the theory they have been taught in…

Early initiation of alcohol consumption by adolescents in reconstructed families may be explained by parenting style

Directory of Open Access Journals (Sweden)

Iakunchykova, Olena

2011-05-01

Full Text Available BACKGROUND. Literature about risk factors of alcohol use points at the association between alcohol use and parenting style. This study investigates the relationship between family structure of adolescents in Ukraine and their initiation of alcohol use with parenting style as a mediating variable.METHODS: Pooled data from the repeated cross-sectional nationally representative survey of classes in Ukrainian secondary schools with target group of all 15-16 year old students, held in 1999, 2003, and 2007, were used for this analysis. Complete data were available for 11019 participants. Main exposures were family structure (full, single parent and reconstructed and perceptions of the relationships with mother and father, rule-setting, control, and support provided by parents. Outcome measure was age when students started consuming alcohol.RESULTS: In bivariate analysis, children in reconstructed families had higher risk for initiating alcohol use at age of 13 or younger (odds ratio 1.37, confidence interval 1,15-1,63 compared to full families. In reconstructed families, adolescents were more likely to be dissatisfied with their relationships with mother compared to intact family structure (8.7% vs. 4.7% and dissatisfied with their relationships with father compared to intact family structure (19,8% vs. 9,1%. Parental support was lacking in higher proportion of reconstructed families, compared to intact family structure (20.7% vs. 15.1%. In the multivariate analysis, controlling for relationship with mother and father, support received from parents, and socio-demographic characteristics, the association between family structure and alcohol drinking initiation was attenuated.CONCLUSIONS: Children in reconstructed families have higher risk of early drinking initiation. This study also supports the hypothesis that dissatisfaction with relationships with parents and lack of support received from parents may mediate the association between family structure

Human eyeball model reconstruction and quantitative analysis.

Science.gov (United States)

Xing, Qi; Wei, Qi

2014-01-01

Determining shape of the eyeball is important to diagnose eyeball disease like myopia. In this paper, we present an automatic approach to precisely reconstruct three dimensional geometric shape of eyeball from MR Images. The model development pipeline involved image segmentation, registration, B-Spline surface fitting and subdivision surface fitting, neither of which required manual interaction. From the high resolution resultant models, geometric characteristics of the eyeball can be accurately quantified and analyzed. In addition to the eight metrics commonly used by existing studies, we proposed two novel metrics, Gaussian Curvature Analysis and Sphere Distance Deviation, to quantify the cornea shape and the whole eyeball surface respectively. The experiment results showed that the reconstructed eyeball models accurately represent the complex morphology of the eye. The ten metrics parameterize the eyeball among different subjects, which can potentially be used for eye disease diagnosis.

[Advantage investigation of totally laparoscopic modified Roux-en-Y reconstruction].

Science.gov (United States)

Liu, Tianzhou; Ma, Zhiming; Sun, Pengda; Li, Jinlong; Fang, Xuedong; Tong, Ti; Zhu, Jiaming

2016-01-01

To investigate the clinical advantage of the application of modified Roux-en-Y reconstruction after totally laparoscopic total gastrectomy. Clinical data of 36 patients who underwent totally laparoscopic total gastrectomy with Roux-en-Y reconstruction by one medical team for gastric adenocarcinoma between January 2014 and December 2014 in the Second Hospital of Jilin University were retrospectively analyzed. Patients were divided into classic Roux-en-Y group (CRY, 16 cases) and modified Roux-en-Y group (MRY, 20 cases) according to reconstructive methods. The data concerning the intraoperative and postoperative situation in two groups were compared. Operation was successfully completed in all the cases without conversion to laparotomy. Compared to CRY group, MRY group had shorter mean operative time [(260.9 ± 21.2) min vs. (287.9 ± 19.0) min, P=0.000], shorter mean reconstruction duration [(32.4 ± 9.2] min vs. (45.4 ± 13.2) min, P=0.001] and less intraoperative bleeding [(50.9 ± 23.5) ml vs. (67.0 ± 20.5) ml, P=0.000]. Jejunum mesentery dissection and jejunum resection were not necessary in MRY group. However, there were no significant differences in lymph nodes harvested, time to flatus, hospital stay and postoperative complications between two groups. As compared to classic Roux-en-Y reconstruction, the modified Roux-en-Y reconstruction can simplify the surgical procedures and achieve similar efficacy. It is feasible and safe, and worth further promotion in clinical practice.

ANALYZING THE EFFICACY OF THE TESTING EFFECT USING KAHOOTTM ON STUDENT PERFORMANCE

Directory of Open Access Journals (Sweden)

Darren H. IWAMOTO

2017-04-01

Full Text Available Lower than expected high-stakes examination scores were being observed in a first-year general psychology class. This research sought an alternate approach that would assist students in preparing for high-stakes examinations. The purpose of this study was to measure the effectiveness of an alternate teaching approach based on the testing effect to address low high-stakes examination scores. This was accomplished through the introduction of an online quizzing application that utilized a game show-like user interface called Kahoot™. The results showed a significant difference in high-stakes examination scores for students who utilized Kahoot™ versus students who did not. It can be suggested that pedagogical tools like Kahoot™ have the potential to enhance and improve high-stakes examination scores at the college and university level. Students that used Kahoot™ felt positive about their experience. The results of this study also suggest that creating a fun and engaging environment also supports improved academic performance.

Image Reconstruction. Chapter 13

Energy Technology Data Exchange (ETDEWEB)

Nuyts, J. [Department of Nuclear Medicine and Medical Imaging Research Center, Katholieke Universiteit Leuven, Leuven (Belgium); Matej, S. [Medical Image Processing Group, Department of Radiology, University of Pennsylvania, Philadelphia, PA (United States)

2014-12-15

This chapter discusses how 2‑D or 3‑D images of tracer distribution can be reconstructed from a series of so-called projection images acquired with a gamma camera or a positron emission tomography (PET) system [13.1]. This is often called an ‘inverse problem’. The reconstruction is the inverse of the acquisition. The reconstruction is called an inverse problem because making software to compute the true tracer distribution from the acquired data turns out to be more difficult than the ‘forward’ direction, i.e. making software to simulate the acquisition. There are basically two approaches to image reconstruction: analytical reconstruction and iterative reconstruction. The analytical approach is based on mathematical inversion, yielding efficient, non-iterative reconstruction algorithms. In the iterative approach, the reconstruction problem is reduced to computing a finite number of image values from a finite number of measurements. That simplification enables the use of iterative instead of mathematical inversion. Iterative inversion tends to require more computer power, but it can cope with more complex (and hopefully more accurate) models of the acquisition process.

Coordinate reconstruction using box reconstruction and projection of X-ray photo

International Nuclear Information System (INIS)

Achmad Suntoro

2011-01-01

Some mathematical formula have been derived for a process of reconstruction to define the coordinate of any point relative to a pre set coordinate system. The process of reconstruction uses a reconstruction box in which each edge's length of the box is known, each top-bottom face and left-right face of the box having a cross marker, and the top face and the right face of the box as plane projections by X-ray source in perspective projection -system. Using the data of the two X-ray projection images, any point inside the reconstruction box, as long as its projection is recorded in the two photos, will be determined its coordinate relative to the midpoint of the reconstruction box as the central point coordinates. (author)

System and method for image reconstruction, analysis, and/or de-noising

KAUST Repository

Laleg-Kirati, Taous-Meriem; Kaisserli, Zineb

2015-01-01

A method and system can analyze, reconstruct, and/or denoise an image. The method and system can include interpreting a signal as a potential of a Schrödinger operator, decomposing the signal into squared eigenfunctions, reducing a design parameter

Reconstruction of a uniform star object from interior x-ray data: uniqueness, stability and algorithm

International Nuclear Information System (INIS)

Van Gompel, Gert; Batenburg, K Joost; Defrise, Michel

2009-01-01

In this paper we consider the problem of reconstructing a two-dimensional star-shaped object of uniform density from truncated projections of the object. In particular, we prove that such an object is uniquely determined by its parallel projections sampled over a full π angular range with a detector that only covers an interior field-of-view, even if the density of the object is not known a priori. We analyze the stability of this reconstruction problem and propose a reconstruction algorithm. Simulation experiments demonstrate that the algorithm is capable of reconstructing a star-shaped object from interior data, even if the interior region is much smaller than the size of the object. In addition, we present results for a heuristic reconstruction algorithm called DART, that was recently proposed. The heuristic method is shown to yield accurate reconstructions if the density is known in advance, and to have a very good stability in the presence of noisy projection data. Finally, the performance of the DBP and DART algorithms is illustrated for the reconstruction of real micro-CT data of a diamond

Analyzing Student and Employer Satisfaction with Cooperative Education through Multiple Data Sources

Science.gov (United States)

Jiang, Yuheng Helen; Lee, Sally Wai Yin; Golab, Lukasz

2015-01-01

This paper reports on the analysis of three years research of undergraduate cooperative work term postings and employer and employee evaluations. The objective of the analysis was to determine the factors affecting student and employer success and satisfaction with the work-integrated learning experience. It was found that students performed…

Segmentation-DrivenTomographic Reconstruction

DEFF Research Database (Denmark)

Kongskov, Rasmus Dalgas

such that the segmentation subsequently can be carried out by use of a simple segmentation method, for instance just a thresholding method. We tested the advantages of going from a two-stage reconstruction method to a one stage segmentation-driven reconstruction method for the phase contrast tomography reconstruction......The tomographic reconstruction problem is concerned with creating a model of the interior of an object from some measured data, typically projections of the object. After reconstructing an object it is often desired to segment it, either automatically or manually. For computed tomography (CT...

One-Stage Immediate Breast Reconstruction: A Concise Review

Directory of Open Access Journals (Sweden)

Nicolò Bertozzi

2017-01-01

Full Text Available Background. One-stage direct-to-implant immediate breast reconstruction (IBR is performed simultaneously with breast cancer resection. We explored indications, techniques, and outcomes of IBR to determine its feasibility, safety, and effectiveness. Material and Methods. We reviewed the available literature on one-stage direct-to-implant IBR, with or without acellular dermal matrix (ADM, synthetic mesh, or autologous fat grafting. We analyzed the indications, preoperative work-up, surgical technique, postoperative care, outcomes, and complications. Results. IBR is indicated for small-to-medium nonptotic breasts and contraindicated in patients who require or have undergone radiotherapy, due to unacceptably high complications rates. Only patients with thick, well-vascularized mastectomy flaps are IBR candidates. Expandable implants should be used for ptotic breasts, while anatomical shaped implants should be used to reconstruct small-to-medium nonptotic breasts. ADMs can be used to cover the implant during IBR and avoid muscle elevation, thereby minimizing postoperative pain. Flap necrosis, reoperation, and implant loss are more common with IBR than conventional two-staged reconstruction, but IBR has advantages such as lack of secondary surgery, faster recovery, and better quality of life. Conclusions. IBR has good outcomes and patient-satisfaction rates. With ADM use, a shift from conventional reconstruction to IBR has occurred. Drawbacks of IBR can be overcome by careful patient selection.

Low rank alternating direction method of multipliers reconstruction for MR fingerprinting.

Science.gov (United States)

Assländer, Jakob; Cloos, Martijn A; Knoll, Florian; Sodickson, Daniel K; Hennig, Jürgen; Lattanzi, Riccardo

2018-01-01

The proposed reconstruction framework addresses the reconstruction accuracy, noise propagation and computation time for magnetic resonance fingerprinting. Based on a singular value decomposition of the signal evolution, magnetic resonance fingerprinting is formulated as a low rank (LR) inverse problem in which one image is reconstructed for each singular value under consideration. This LR approximation of the signal evolution reduces the computational burden by reducing the number of Fourier transformations. Also, the LR approximation improves the conditioning of the problem, which is further improved by extending the LR inverse problem to an augmented Lagrangian that is solved by the alternating direction method of multipliers. The root mean square error and the noise propagation are analyzed in simulations. For verification, in vivo examples are provided. The proposed LR alternating direction method of multipliers approach shows a reduced root mean square error compared to the original fingerprinting reconstruction, to a LR approximation alone and to an alternating direction method of multipliers approach without a LR approximation. Incorporating sensitivity encoding allows for further artifact reduction. The proposed reconstruction provides robust convergence, reduced computational burden and improved image quality compared to other magnetic resonance fingerprinting reconstruction approaches evaluated in this study. Magn Reson Med 79:83-96, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Kinematic analysis of anterior cruciate ligament reconstruction in total knee arthroplasty

Science.gov (United States)

Liu, Hua-Wei; Ni, Ming; Zhang, Guo-Qiang; Li, Xiang; Chen, Hui; Zhang, Qiang; Chai, Wei; Zhou, Yong-Gang; Chen, Ji-Ying; Liu, Yu-Liang; Cheng, Cheng-Kung; Wang, Yan

2016-01-01

Background: This study aims to retain normal knee kinematics after knee replacement surgeries by reconstructing anterior cruciate ligament during total knee arthroplasty. Method: We use computational simulation tools to establish four dynamic knee models, including normal knee model, posterior cruciate ligament retaining knee model, posterior cruciate ligament substituting knee model, and anterior cruciate ligament reconstructing knee model. Our proposed method utilizes magnetic resonance images to reconstruct solid bones and attachments of ligaments, and assemble femoral and tibial components according representative literatures and operational specifications. Dynamic data of axial tibial rotation and femoral translation from full-extension to 135 were measured for analyzing the motion of knee models. Findings: The computational simulation results show that comparing with the posterior cruciate ligament retained knee model and the posterior cruciate ligament substituted knee model, reconstructing anterior cruciate ligament improves the posterior movement of the lateral condyle, medial condyle and tibial internal rotation through a full range of flexion. The maximum posterior translations of the lateral condyle, medial condyle and tibial internal rotation of the anterior cruciate ligament reconstructed knee are 15.3 mm, 4.6 mm and 20.6 at 135 of flexion. Interpretation: Reconstructing anterior cruciate ligament in total knee arthroplasty has been approved to be an more efficient way of maintaining normal knee kinematics comparing to posterior cruciate ligament retained and posterior cruciate ligament substituted total knee arthroplasty. PMID:27347334

Results of auricular helical rim reconstruction with post-auricular tube flap.

Science.gov (United States)

Iljin, Aleksandra; Lewandowicz, Edward; Antoszewski, Bogusław; Zieliński, Tomasz

2016-01-01

The aim of the study was to present our experience with post-auricular tube flap (ptf) and clinical evaluation of the results following auricular helical rim reconstruction with this technique in patients after trauma. We analyzed the results in 12 patients who underwent three-staged auricular helical rim reconstruction with ptf following trauma in the Department of Plastic, Reconstructive and Aesthetic Surgery between 2005-2014. The patients were followed-up for at least 1 year. We evaluated early and long-term results after surgery including plastic surgeon's and patient's opinion. Postoperative results were satisfactory (very good) in 10 cases, both in the opinion of the plastic surgeon and patients. Transient venous congestion of the helix occurred in two cases (16.6%). This complication did not have any influence on estimation of the results after surgery. Delayed wound healing in the poles of the reconstructed helical edge, as well as non-aesthetic helical scars with imperfections of helical rim, were seen in another two patients (16.6%). 1. Post-auricular tube flap reconstructions after helical rim trauma allowed for complete restoration of contour, size and orientation of the helix and the whole operated ear, which confirms the efficiency of the applied technique. 2. Reconstructive surgery with post-auricular tube flap in patients with auricular helical rim defects contributed to postoperative satisfaction in both patients and doctors' estimations.

Method of reconstructing a moving pulse

Energy Technology Data Exchange (ETDEWEB)

Howard, S J; Horton, R D; Hwang, D Q; Evans, R W; Brockington, S J; Johnson, J [UC Davis Department of Applied Science, Livermore, CA, 94551 (United States)

2007-11-15

We present a method of analyzing a set of N time signals f{sub i}(t) that consist of local measurements of the same physical observable taken at N sequential locations Z{sub i} along the length of an experimental device. The result is an algorithm for reconstructing an approximation F(z,t) of the field f(z,t) in the inaccessible regions between the points of measurement. We also explore the conditions needed for this approximation to hold, and test the algorithm under a variety of conditions. We apply this method to analyze the magnetic field measurements taken on the Compact Toroid Injection eXperiment (CTIX) plasma accelerator; providing a direct means of visualizing experimental data, quantifying global properties, and benchmarking simulation.

RECONSTRUCTION OF FACIAL SKIN DEFECT BY VARIOUS FLAPS : OUR EXPERIENCE

Directory of Open Access Journals (Sweden)

Atishkumar B.

2015-08-01

Full Text Available INTRODUCTION : Face represents complete personality of human being. Cosmetically it is very important part of a person especially for woman. There are many situations when due to disease or trauma, facial defect arises, which requires reconstruction by either local or distant surgical flaps . METHODS AND MATERIALS : In rural places, we come across many patients suffering from trauma and skin malignancy of face. These patients require reconstruction done esthetically with local flaps. Objective of this study is to share our exper ience of providing esthetically good results at our secondary referral care center. Hereby, we present case series of 14 patients operated at our institute. These patients were analyzed according to the age, sex, nature of injury and anatomical location of lesion on the face. All these patients were operated and reconstruction of defect was done with various local flaps best suited for respective lesion, under local anesthesia or sedation. Post - operative nature of wound was analyzed for flap viability or fl ap necrosis . RESULTS : Amongst them were 7 male and 7 female, ages ranging from 4 to 80 years. 7out of 14 patients were of basal cell carcinoma, 4 were due to trauma, 2 were due to dog bite and 1 case of recurrent pleomorphic adenoma at root of nose. All patients had excellent flap viability at end of 6 months and flap achieving almost similar color and contour as that of surrounding skin. CONCLUSION : Reconstruction of facial defects by local flaps is very easy and cost effective technique. This can be don e even at secondary referral care centre with minimal availability of facilities

Analysis of PWR control rod ejection accident with the coupled code system SKETCH-INS/TRACE by incorporating pin power reconstruction model

International Nuclear Information System (INIS)

Nakajima, T.; Sakai, T.

2010-01-01

The pin power reconstruction model was incorporated in the 3-D nodal kinetics code SKETCH-INS in order to produce accurate calculation of three-dimensional pin power distributions throughout the reactor core. In order to verify the employed pin power reconstruction model, the PWR MOX/UO_2 core transient benchmark problem was analyzed with the coupled code system SKETCH-INS/TRACE by incorporating the model and the influence of pin power reconstruction model was studied. SKETCH-INS pin power distributions for 3 benchmark problems were compared with the PARCS solutions which were provided by the host organisation of the benchmark. SKETCH-INS results were in good agreement with the PARCS results. The capability of employed pin power reconstruction model was confirmed through the analysis of benchmark problems. A PWR control rod ejection benchmark problem was analyzed with the coupled code system SKETCH-INS/ TRACE by incorporating the pin power reconstruction model. The influence of pin power reconstruction model was studied by comparing with the result of conventional node averaged flux model. The results indicate that the pin power reconstruction model has significant effect on the pin powers during transient and hence on the fuel enthalpy

Effect of PYTHIA8 tunes on event shapes and top-quark reconstruction in e$^+$e$^-$ annihilation at CLIC

CERN Document Server

Chekanov, Sergei; Fischer, Andrew; Zhang, Jinlong

2017-01-01

This paper describes the effect of PYTHIA8 tunes on event simulation of e$^+$e$^-$ collisions with center-of-mass (CM) energies of 380 GeV and 3 TeV at the proposed CLIC collider. Event shapes, such as thrust, thrust major, thrust minor, oblateness, as well as particle multiplicities have been analyzed and relative differences with respect to the default PYTHIA8 tune were determined. The effect of tunes on top-mass reconstruction in the resolved and boosted regimes was analyzed. No statistically significant variation for reconstructed top masses using invariant masses of three jets was found for events with a CM energy of 380 GeV. For the fully boosted top reconstruction at a CM energy of 3 TeV, a significant shift in reconstructed top mass of about 700 MeV for the "Montull" tune was observed. This shift correlates with an increase in particle multiplicity compared to all other PYTHIA8 tunes.

Mining Educational Data to Analyze the Student Motivation Behavior

OpenAIRE

Kunyanuth Kularbphettong; Cholticha Tongsiri

2012-01-01

The purpose of this research aims to discover the knowledge for analysis student motivation behavior on e-Learning based on Data Mining Techniques, in case of the Information Technology for Communication and Learning Course at Suan Sunandha Rajabhat University. The data mining techniques was applied in this research including association rules, classification techniques. The results showed that using data mining technique can indicate the important variables that influenc...

Comparison of pure and hybrid iterative reconstruction techniques with conventional filtered back projection: Image quality assessment in the cervicothoracic region

Energy Technology Data Exchange (ETDEWEB)

Katsura, Masaki, E-mail: mkatsura-tky@umin.ac.jp [Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Sato, Jiro; Akahane, Masaaki; Matsuda, Izuru; Ishida, Masanori; Yasaka, Koichiro; Kunimatsu, Akira; Ohtomo, Kuni [Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan)

2013-02-15

Objectives: To evaluate the impact on image quality of three different image reconstruction techniques in the cervicothoracic region: model-based iterative reconstruction (MBIR), adaptive statistical iterative reconstruction (ASIR), and filtered back projection (FBP). Methods: Forty-four patients underwent unenhanced standard-of-care clinical computed tomography (CT) examinations which included the cervicothoracic region with a 64-row multidetector CT scanner. Images were reconstructed with FBP, 50% ASIR-FBP blending (ASIR50), and MBIR. Two radiologists assessed the cervicothoracic region in a blinded manner for streak artifacts, pixilated blotchy appearances, critical reproduction of visually sharp anatomical structures (thyroid gland, common carotid artery, and esophagus), and overall diagnostic acceptability. Objective image noise was measured in the internal jugular vein. Data were analyzed using the sign test and pair-wise Student's t-test. Results: MBIR images had significant lower quantitative image noise (8.88 ± 1.32) compared to ASIR images (18.63 ± 4.19, P < 0.01) and FBP images (26.52 ± 5.8, P < 0.01). Significant improvements in streak artifacts of the cervicothoracic region were observed with the use of MBIR (P < 0.001 each for MBIR vs. the other two image data sets for both readers), while no significant difference was observed between ASIR and FBP (P > 0.9 for ASIR vs. FBP for both readers). MBIR images were all diagnostically acceptable. Unique features of MBIR images included pixilated blotchy appearances, which did not adversely affect diagnostic acceptability. Conclusions: MBIR significantly improves image noise and streak artifacts of the cervicothoracic region over ASIR and FBP. MBIR is expected to enhance the value of CT examinations for areas where image noise and streak artifacts are problematic.

Vaginal reconstruction

International Nuclear Information System (INIS)

Lesavoy, M.A.

1985-01-01

Vaginal reconstruction can be an uncomplicated and straightforward procedure when attention to detail is maintained. The Abbe-McIndoe procedure of lining the neovaginal canal with split-thickness skin grafts has become standard. The use of the inflatable Heyer-Schulte vaginal stent provides comfort to the patient and ease to the surgeon in maintaining approximation of the skin graft. For large vaginal and perineal defects, myocutaneous flaps such as the gracilis island have been extremely useful for correction of radiation-damaged tissue of the perineum or for the reconstruction of large ablative defects. Minimal morbidity and scarring ensue because the donor site can be closed primarily. With all vaginal reconstruction, a compliant patient is a necessity. The patient must wear a vaginal obturator for a minimum of 3 to 6 months postoperatively and is encouraged to use intercourse as an excellent obturator. In general, vaginal reconstruction can be an extremely gratifying procedure for both the functional and emotional well-being of patients

Intra-European Student Mobility in International Higher Education Circuits. Europe on the Move

NARCIS (Netherlands)

Van Mol, C.

2014-01-01

Intra-European Student Mobility in International Higher Education Circuits focuses on the phenomenon of international student exchanges in Europe. Strongly interdisciplinary in its focus, this book empirically addresses four main research questions: who goes abroad, how students reconstruct their

Breast Reconstruction After Mastectomy

Science.gov (United States)

... Cancer Prevention Genetics of Breast & Gynecologic Cancers Breast Cancer Screening Research Breast Reconstruction After Mastectomy On This Page What is breast reconstruction? How do surgeons use implants to reconstruct a woman’s breast? How do surgeons ...

Analyzing Student Aid Packaging To Improve Low-Income and Minority Student Access, Retention and Degree Completion. AIR 1999 Annual Forum Paper.

Science.gov (United States)

Fenske, Robert H.; Porter, John D.; DuBrock, Caryl P.

This study examined the persistence of and financial aid to needy students, underrepresented minority students, and women students, especially those majoring in science, engineering, and mathematics at a large public research university. An institutional student tracking and student financial aid database was used to follow four freshmen cohorts…

Estimation of 3D reconstruction errors in a stereo-vision system

Science.gov (United States)

Belhaoua, A.; Kohler, S.; Hirsch, E.

2009-06-01

The paper presents an approach for error estimation for the various steps of an automated 3D vision-based reconstruction procedure of manufactured workpieces. The process is based on a priori planning of the task and built around a cognitive intelligent sensory system using so-called Situation Graph Trees (SGT) as a planning tool. Such an automated quality control system requires the coordination of a set of complex processes performing sequentially data acquisition, its quantitative evaluation and the comparison with a reference model (e.g., CAD object model) in order to evaluate quantitatively the object. To ensure efficient quality control, the aim is to be able to state if reconstruction results fulfill tolerance rules or not. Thus, the goal is to evaluate independently the error for each step of the stereo-vision based 3D reconstruction (e.g., for calibration, contour segmentation, matching and reconstruction) and then to estimate the error for the whole system. In this contribution, we analyze particularly the segmentation error due to localization errors for extracted edge points supposed to belong to lines and curves composing the outline of the workpiece under evaluation. The fitting parameters describing these geometric features are used as quality measure to determine confidence intervals and finally to estimate the segmentation errors. These errors are then propagated through the whole reconstruction procedure, enabling to evaluate their effect on the final 3D reconstruction result, specifically on position uncertainties. Lastly, analysis of these error estimates enables to evaluate the quality of the 3D reconstruction, as illustrated by the shown experimental results.

Application of dual volume reconstruction technique in embolization of intracranial aneurysms

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Xiang-hai ZHANG

2014-03-01

Full Text Available Objective　To explore the value of dual volume reconstruction technique in Guglielmi detachable coil (GDC embolization of intracranial aneurysms. Methods　Three-dimensional imaging data of 20 patients received GDC embolization of intracranial aneurysms from Jun. 2012 to Apr. 2013 were analyzed for dual volume reconstruction. The value of application of dual volume reconstruction was evaluated by the detection rate of coils bolus, degree of aneurysm occlusion, the length of aneurysm sac and aneurysm neck before and after embolization, and the characteristics and clinical value of the reconstructed images. Results 　A total of 20 coil boluses were detected by dual volume reconstruction images, and the detection rate was 100%. Among all of 20 patients, no visualization of contrast medium in the aneurysm was found in 13 patients, while contrast agent was found in the aneurysm sac in 3 patients and in the aneurysm neck in 4 patients. The length of aneurysm neck and sac was somewhat changed before and after embolization with no statistically significant difference (P>0.05. The dual volume reconstruction could reveal coil bolus, vessels, cranium and fusion images, and the aneurysms could be shown by different imaging modes according to the clinical requirement. Conclusion　Dual volume reconstruction technique can display the location of coil bolus, degree of occlusion and aneurysm size, and evaluate the embolization effect by multifarious imaging modes, providing a great deal of information for the evaluation of GDC embolization of intracranial aneurysm. DOI: 10.11855/j.issn.0577-7402.2014.02.13

Comprehensive Use of Curvature for Robust and Accurate Online Surface Reconstruction.

Science.gov (United States)

Lefloch, Damien; Kluge, Markus; Sarbolandi, Hamed; Weyrich, Tim; Kolb, Andreas

2017-12-01

Interactive real-time scene acquisition from hand-held depth cameras has recently developed much momentum, enabling applications in ad-hoc object acquisition, augmented reality and other fields. A key challenge to online reconstruction remains error accumulation in the reconstructed camera trajectory, due to drift-inducing instabilities in the range scan alignments of the underlying iterative-closest-point (ICP) algorithm. Various strategies have been proposed to mitigate that drift, including SIFT-based pre-alignment, color-based weighting of ICP pairs, stronger weighting of edge features, and so on. In our work, we focus on surface curvature as a feature that is detectable on range scans alone and hence does not depend on accurate multi-sensor alignment. In contrast to previous work that took curvature into consideration, however, we treat curvature as an independent quantity that we consistently incorporate into every stage of the real-time reconstruction pipeline, including densely curvature-weighted ICP, range image fusion, local surface reconstruction, and rendering. Using multiple benchmark sequences, and in direct comparison to other state-of-the-art online acquisition systems, we show that our approach significantly reduces drift, both when analyzing individual pipeline stages in isolation, as well as seen across the online reconstruction pipeline as a whole.

Evidence-Based ACL Reconstruction

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E. Carlos RODRIGUEZ-MERCHAN

2015-01-01

Full Text Available There is controversy in the literature regarding a number of topics related to anterior cruciate ligament (ACLreconstruction. The purpose of this article is to answer the following questions: 1 Bone patellar tendon bone (BPTB reconstruction or hamstring reconstruction (HR; 2 Double bundle or single bundle; 3 Allograft or authograft; 4 Early or late reconstruction; 5 Rate of return to sports after ACL reconstruction; 6 Rate of osteoarthritis after ACL reconstruction. A Cochrane Library and PubMed (MEDLINE search of systematic reviews and meta-analysis related to ACL reconstruction was performed. The key words were: ACL reconstruction, systematic reviews and meta-analysis. The main criteria for selection were that the articles were systematic reviews and meta-analysesfocused on the aforementioned questions. Sixty-nine articles were found, but only 26 were selected and reviewed because they had a high grade (I-II of evidence. BPTB-R was associated with better postoperative knee stability but with a higher rate of morbidity. However, the results of both procedures in terms of functional outcome in the long-term were similar. The double-bundle ACL reconstruction technique showed better outcomes in rotational laxity, although functional recovery was similar between single-bundle and double-bundle. Autograft yielded better results than allograft. There was no difference between early and delayed reconstruction. 82% of patients were able to return to some kind of sport participation. 28% of patients presented radiological signs of osteoarthritis with a follow-up of minimum 10 years.

Analyzing high school students’ reasoning about electromagnetic induction

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Katarina Jelicic

2017-02-01

Full Text Available Electromagnetic induction is an important, yet complex, physics topic that is a part of Croatian high school curriculum. Nine Croatian high school students of different abilities in physics were interviewed using six demonstration experiments from electromagnetism (three of them concerned the topic of electromagnetic induction. Students were asked to observe, describe, and explain the experiments. The analysis of students’ explanations indicated the existence of many conceptual and reasoning difficulties with the basic concepts of electromagnetism, and especially with recognizing and explaining the phenomenon of electromagnetic induction. Three student mental models of electromagnetic induction, formed during the interviews, which reoccurred among students, are described and analyzed within the knowledge-in-pieces framework.

Ultralow dose computed tomography attenuation correction for pediatric PET CT using adaptive statistical iterative reconstruction

International Nuclear Information System (INIS)

Brady, Samuel L.; Shulkin, Barry L.

2015-01-01

Purpose: To develop ultralow dose computed tomography (CT) attenuation correction (CTAC) acquisition protocols for pediatric positron emission tomography CT (PET CT). Methods: A GE Discovery 690 PET CT hybrid scanner was used to investigate the change to quantitative PET and CT measurements when operated at ultralow doses (10–35 mA s). CT quantitation: noise, low-contrast resolution, and CT numbers for 11 tissue substitutes were analyzed in-phantom. CT quantitation was analyzed to a reduction of 90% volume computed tomography dose index (0.39/3.64; mGy) from baseline. To minimize noise infiltration, 100% adaptive statistical iterative reconstruction (ASiR) was used for CT reconstruction. PET images were reconstructed with the lower-dose CTAC iterations and analyzed for: maximum body weight standardized uptake value (SUV bw ) of various diameter targets (range 8–37 mm), background uniformity, and spatial resolution. Radiation dose and CTAC noise magnitude were compared for 140 patient examinations (76 post-ASiR implementation) to determine relative dose reduction and noise control. Results: CT numbers were constant to within 10% from the nondose reduced CTAC image for 90% dose reduction. No change in SUV bw , background percent uniformity, or spatial resolution for PET images reconstructed with CTAC protocols was found down to 90% dose reduction. Patient population effective dose analysis demonstrated relative CTAC dose reductions between 62% and 86% (3.2/8.3–0.9/6.2). Noise magnitude in dose-reduced patient images increased but was not statistically different from predose-reduced patient images. Conclusions: Using ASiR allowed for aggressive reduction in CT dose with no change in PET reconstructed images while maintaining sufficient image quality for colocalization of hybrid CT anatomy and PET radioisotope uptake

Ultralow dose computed tomography attenuation correction for pediatric PET CT using adaptive statistical iterative reconstruction

Energy Technology Data Exchange (ETDEWEB)

Brady, Samuel L., E-mail: samuel.brady@stjude.org [Division of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105 (United States); Shulkin, Barry L. [Nuclear Medicine and Department of Radiological Sciences, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105 (United States)

2015-02-15

Purpose: To develop ultralow dose computed tomography (CT) attenuation correction (CTAC) acquisition protocols for pediatric positron emission tomography CT (PET CT). Methods: A GE Discovery 690 PET CT hybrid scanner was used to investigate the change to quantitative PET and CT measurements when operated at ultralow doses (10–35 mA s). CT quantitation: noise, low-contrast resolution, and CT numbers for 11 tissue substitutes were analyzed in-phantom. CT quantitation was analyzed to a reduction of 90% volume computed tomography dose index (0.39/3.64; mGy) from baseline. To minimize noise infiltration, 100% adaptive statistical iterative reconstruction (ASiR) was used for CT reconstruction. PET images were reconstructed with the lower-dose CTAC iterations and analyzed for: maximum body weight standardized uptake value (SUV{sub bw}) of various diameter targets (range 8–37 mm), background uniformity, and spatial resolution. Radiation dose and CTAC noise magnitude were compared for 140 patient examinations (76 post-ASiR implementation) to determine relative dose reduction and noise control. Results: CT numbers were constant to within 10% from the nondose reduced CTAC image for 90% dose reduction. No change in SUV{sub bw}, background percent uniformity, or spatial resolution for PET images reconstructed with CTAC protocols was found down to 90% dose reduction. Patient population effective dose analysis demonstrated relative CTAC dose reductions between 62% and 86% (3.2/8.3–0.9/6.2). Noise magnitude in dose-reduced patient images increased but was not statistically different from predose-reduced patient images. Conclusions: Using ASiR allowed for aggressive reduction in CT dose with no change in PET reconstructed images while maintaining sufficient image quality for colocalization of hybrid CT anatomy and PET radioisotope uptake.

Improving tritium exposure reconstructions using accelerator mass spectrometry

International Nuclear Information System (INIS)

Love, A.H.; Hunt, J.R.; Vogel, J.S.; Knezovich, J.P.

2004-01-01

Direct measurement of tritium atoms by accelerator mass spectrometry (AMS) enables rapid low-activity tritium measurements from milligram-sized samples and permits greater ease of sample collection, faster throughput, and increased spatial and/or temporal resolution. Because existing methodologies for quantifying tritium have some significant limitations, the development of tritium AMS has allowed improvements in reconstructing tritium exposure concentrations from environmental measurements and provides an important additional tool in assessing the temporal and spatial distribution of chronic exposure. Tritium exposure reconstructions using AMS were previously demonstrated for a tree growing on known levels of tritiated water and for trees exposed to atmospheric releases of tritiated water vapor. In these analyses, tritium levels were measured from milligram-sized samples with sample preparation times of a few days. Hundreds of samples were analyzed within a few months of sample collection and resulted in the reconstruction of spatial and temporal exposure from tritium releases. Although the current quantification limit of tritium AMS is not adequate to determine natural environmental variations in tritium concentrations, it is expected to be sufficient for studies assessing possible health effects from chronic environmental tritium exposure. (orig.)

Improving tritium exposure reconstructions using accelerator mass spectrometry

Science.gov (United States)

Hunt, J. R.; Vogel, J. S.; Knezovich, J. P.

2010-01-01

Direct measurement of tritium atoms by accelerator mass spectrometry (AMS) enables rapid low-activity tritium measurements from milligram-sized samples and permits greater ease of sample collection, faster throughput, and increased spatial and/or temporal resolution. Because existing methodologies for quantifying tritium have some significant limitations, the development of tritium AMS has allowed improvements in reconstructing tritium exposure concentrations from environmental measurements and provides an important additional tool in assessing the temporal and spatial distribution of chronic exposure. Tritium exposure reconstructions using AMS were previously demonstrated for a tree growing on known levels of tritiated water and for trees exposed to atmospheric releases of tritiated water vapor. In these analyses, tritium levels were measured from milligram-sized samples with sample preparation times of a few days. Hundreds of samples were analyzed within a few months of sample collection and resulted in the reconstruction of spatial and temporal exposure from tritium releases. Although the current quantification limit of tritium AMS is not adequate to determine natural environmental variations in tritium concentrations, it is expected to be sufficient for studies assessing possible health effects from chronic environmental tritium exposure. PMID:14735274

Macromolecular 3D SEM reconstruction strategies: Signal to noise ratio and resolution

International Nuclear Information System (INIS)

Woodward, J.D.; Wepf, R.A.

2014-01-01

Three-dimensional scanning electron microscopy generates quantitative volumetric structural data from SEM images of macromolecules. This technique provides a quick and easy way to define the quaternary structure and handedness of protein complexes. Here, we apply a variety of preparation and imaging methods to filamentous actin in order to explore the relationship between resolution, signal-to-noise ratio, structural preservation and dataset size. This information can be used to define successful imaging strategies for different applications. - Highlights: • F-actin SEM datasets were collected using 8 different preparation/ imaging techniques. • Datasets were reconstructed by back projection and compared/analyzed • 3DSEM actin reconstructions can be produced with <100 views of the asymmetric unit. • Negatively stained macromolecules can be reconstructed by 3DSEM to ∼3 nm resolution

Identifying Students' Expectancy-Value Beliefs: A Latent Class Analysis Approach to Analyzing Middle School Students' Science Self-Perceptions

Science.gov (United States)

Phelan, Julia; Ing, Marsha; Nylund-Gibson, Karen; Brown, Richard S.

2017-01-01

This study extends current research by organizing information about students' expectancy-value achievement motivation, in a way that helps parents and teachers identify specific entry points to encourage and support students' science aspirations. This study uses latent class analysis to describe underlying differences in ability beliefs, task…

[Reconstructive methods after Fournier gangrene].

Science.gov (United States)

Wallner, C; Behr, B; Ring, A; Mikhail, B D; Lehnhardt, M; Daigeler, A

2016-04-01

Fournier's gangrene is a variant of the necrotizing fasciitis restricted to the perineal and genital region. It presents as an acute life-threatening disease and demands rapid surgical debridement, resulting in large soft tissue defects. Various reconstructive methods have to be applied to reconstitute functionality and aesthetics. The objective of this work is to identify different reconstructive methods in the literature and compare them to our current concepts for reconstructing defects caused by Fournier gangrene. Analysis of the current literature and our reconstructive methods on Fournier gangrene. The Fournier gangrene is an emergency requiring rapid, calculated antibiotic treatment and radical surgical debridement. After the acute phase of the disease, appropriate reconstructive methods are indicated. The planning of the reconstruction of the defect depends on many factors, especially functional and aesthetic demands. Scrotal reconstruction requires a higher aesthetic and functional reconstructive degree than perineal cutaneous wounds. In general, thorough wound hygiene, proper pre-operative planning, and careful consideration of the patient's demands are essential for successful reconstruction. In the literature, various methods for reconstruction after Fournier gangrene are described. Reconstruction with a flap is required for a good functional result in complex regions as the scrotum and penis, while cutaneous wounds can be managed through skin grafting. Patient compliance and tissue demand are crucial factors in the decision-making process.

Shaping the breast in secondary microsurgical breast reconstruction: single- vs. two-esthetic unit reconstruction.

Science.gov (United States)

Gravvanis, Andreas; Smith, Roger W

2010-10-01

The esthetic outcome is dictated essentially not only by the position, size, and shape of the reconstructed breast, but also by the extra scaring involved. In the present study, we conducted a visual analog scale survey to compare the esthetic outcome in delayed autologous breast reconstruction following two different abdominal flaps inset. Twenty-five patients had their reconstruction using the Single-esthetic Unit principle and were compared with 25 patients that their breast was reconstructed using the Two-Esthetic Unit principle. Photographic images were formulated to a PowerPoint presentation and cosmetic outcomes were assessed from 30 physicians, by means of a Questionnaire and a visual analog scale. Our data showed that the single-esthetic unit breast reconstruction presents significant advantages over the traditional two-esthetic units, due to inconspicuous flap reconstruction, better position of the inframammary fold, and more natural transition from native and reconstructed tissues. Moreover, patient self-evaluation of esthetic outcome and quality of life showed that single-esthetic unit reconstruction is associated with higher patient satisfaction, therefore should be considered the method of choice. © 2010 Wiley-Liss, Inc.

Our Clinical Experience in Lower Eyelid Reconstruction and Comparison of Reconstruction Techniques.

Directory of Open Access Journals (Sweden)

Erol Kesiktas

2011-03-01

Full Text Available Lower eyelid reconstruction after tumor resection or trauma is extremely important in order to obtain the protection of the globe and it requires extra care. The aim of this study is to evaluate the techniques that we use in lower eyelid reconstruction. Between the years of 1999-2009, a total of 23 patients who had lower eyelid defects due to tumor resection (21 patients or trauma (2 patients were reconstructed by the use of various flaps. Eleven of the patients were women and twelve of them were men. Average age was 60.7. For the reconstruction 13 Mustarde flap, 9 bipedicled Tripier flap, 1 Tenzel flap and 1 bipedicled infraorbital flaps were used. Average postoperative follow up interval was 35 months. (18-47 months. Flap necrosis, function loss in the lower lid were not experienced in any of the patients. Cosmetically satisfactory results were obtained. In lower eyelid reconstruction, the size of the defect and the amount of skin around must be carefully evaluated and should be considered while planning the reconstruction. [Cukurova Med J 2011; 36(1: 15-23

The Cost-Effectiveness of Anterior Cruciate Ligament Reconstruction in Competitive Athletes.

Science.gov (United States)

Stewart, Bruce A; Momaya, Amit M; Silverstein, Marc D; Lintner, David

2017-01-01

Competitive athletes value the ability to return to competitive play after the treatment of anterior cruciate ligament (ACL) injuries. ACL reconstruction has high success rates for return to play, but some studies indicate that patients may do well with nonoperative physical therapy treatment. To evaluate the cost-effectiveness of the treatment of acute ACL tears with either initial surgical reconstruction or physical therapy in competitive athletes. Economic and decision analysis; Level of evidence, 2. The incremental cost, incremental effectiveness, and incremental cost-effectiveness ratio (ICER) of ACL reconstruction compared with physical therapy were calculated from a cost-effectiveness analysis of ACL reconstruction compared with physical therapy for the initial management of acute ACL injuries in competitive athletes. The ACL reconstruction strategy and the physical therapy strategy were represented as Markov models. Costs and quality-adjusted life-years (QALYs) were evaluated over a 6-year time horizon and were analyzed from a societal perspective. Quality of life and probabilities of clinical outcomes were obtained from the peer-reviewed literature, and costs were compiled from a large academic hospital in the United States. One-way, 2-way, and probabilistic sensitivity analyses were used to assess the effect of uncertainty in variables on the ICER of ACL reconstruction. The ICER of ACL reconstruction compared with physical therapy was $22,702 per QALY gained. The ICER was most sensitive to the quality of life of returning to play or not returning to play, costs, and duration of follow-up but relatively insensitive to the rates and costs of complications, probabilities of return to play for both operative and nonoperative treatments, and discount rate. ACL reconstruction is a cost-effective strategy for competitive athletes with an ACL injury.

Novel image reconstruction algorithm for multi-phase flow tomography system using γ ray method

International Nuclear Information System (INIS)

Hao Kuihong; Wang Huaxiang; Gao Mei

2007-01-01

After analyzing the reason of image reconstructed algorithm by using the conventional back projection (IBP) is prone to produce spurious line, and considering the characteristic of multi-phase flow tomography, a novel image reconstruction algorithm is proposed, which carries out the intersection calculation using back projection data. This algorithm can obtain a perfect system point spread function, and can eliminate spurious line better. Simulating results show that the algorithm is effective for identifying multi-phase flow pattern. (authors)

Applications of Computer Technology in Complex Craniofacial Reconstruction

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Kristopher M. Day, MD

2018-03-01

Conclusion:. Modern 3D technology allows the surgeon to better analyze complex craniofacial deformities, precisely plan surgical correction with computer simulation of results, customize osteotomies, plan distractions, and print 3DPCI, as needed. The use of advanced 3D computer technology can be applied safely and potentially improve aesthetic and functional outcomes after complex craniofacial reconstruction. These techniques warrant further study and may be reproducible in various centers of care.

Transportal anterior cruciate ligament reconstruction with quadrupled hamstring tendon graft: A prospective outcome study

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Chandan Kumar

2017-01-01

Full Text Available Background: Anterior cruciate ligament (ACL reconstruction has been one of the most commonly performed procedures throughout the world. Unsatisfactory outcome with conventional ACL reconstruction has been attributed to nonanatomic graft placement. Researchers have advised placing the graft in the native footprint of ACL to avoid nonanatomic graft placement. The goal of this study was to analyze the outcome of anatomic single bundle ACL reconstruction using transportal technique. Materials and Methods: This was a prospective outcome study conducted on 85 consecutive patients of ACL reconstruction of which 62 patients met inclusion and exclusion criteria and were analyzed for final results. All the patients underwent ACL reconstruction by quadrupled hamstring tendon graft using transportal technique and the accessory anteromedial (AAM portal for femoral tunnel creation. The graft was fixed with endobutton on femoral side and bioabsorbable screw on the tibial side. Patients were evaluated for range of motion, International Knee Documentation Committee (IKDC score, and Lysholm scores at a minimum followup period of 2 years. The mean pre- and postoperative scores were compared using Wilcoxon signed-rank test. Results: The mean Lysholm and IKDC scores improved significantly (P < 0.0001 from preoperative value. According to IKDC score, 90.3% (n = 56 were either normal or near normal at final followup. According to Lysholm score, 75.8% of patients had excellent and 13.3% had good results. Preoperatively, pivot shift was present in 85.5% (n = 53 of patients which reduced to 4.8% (n = 3 postoperatively. Infection and knee stiffness occurred in two patients, and femoral tunnel blowout and graft re-rupture occurred in one patient each. Conclusion: Anatomic ACL reconstruction by AAM portal is a reproducible technique which gives good clinical outcome at short-term followup.

Early and late complications in the reconstructed mandible with free fibula flaps.

Science.gov (United States)

van Gemert, Johannes T M; Abbink, Jan H; van Es, Robert J J; Rosenberg, Antoine J W P; Koole, Ron; Van Cann, Ellen M

2018-03-01

Evaluation of mandibular reconstructions with free fibula flaps. Identification of factors associated with major recipient site complications, that is, necessitating surgical intervention under general anaesthesia. Seventy-nine reconstructions were included. The following factors were analyzed: fixation type, number of osteotomies, site of defect (bilateral/unilateral), surgeon, sex, ASA classification, continuous smoking, pathological N-stage, age, defect size, flap ischemic time, and postoperative radiotherapy. Proportional hazards regression was used to test the effect on the time between reconstruction and intervention. Sixty-nine (87%) of the 79 fibula flaps were successful at the last follow-up. Forty-eight major recipient site complications occurred in 41 reconstructions. Nineteen complications required surgical intervention within six weeks and were mostly vascular problems, necessitating immediate intervention. These early complications were associated with defects crossing the midline, with an estimated relative risk of 5.3 (CI 1.1-20, P = 0.01). Twenty-nine complications required surgical intervention more than 6 weeks after the reconstruction. These late complications generally occurred after months or years, and were associated with smoking, with an estimated relative risk of 2.8 (CI 1.0-8.3, P = 0.05). Fibula flaps crossing the midline have a higher risk of early major recipient site complications than unilateral reconstructions. Smoking increases the risk of late complications. © 2018 The Authors. Journal of Surgical Oncology Published by Wiley Periodicals, Inc.

Orbital floor reconstruction using a tensor fascia lata sling after total maxillectomy.

Science.gov (United States)

Jung, Bok Ki; Yun, In Sik; Lee, Won Jai; Lew, Dae Hyun; Choi, Eun Chang; Lee, Dong Won

2016-05-01

Reconstruction after total maxillectomy with extensive orbital floor defects poses a significant challenge for the reconstruction. The aim of this study is to present the outcomes of orbital floor reconstruction using tensor fascia lata slings after total maxillectomy and to compare these results to orbital floor reconstruction using alloplastic implants. This was a retrospective analysis of 19 consecutive patients who underwent tumor resection with orbital floor removal for malignancies. Reconstructions were performed using either tensor fascia lata slings (Group A) or alloplastic implants (Group B). The early and late postoperative outcomes such as wound infection, plate exposure, ectropion, diplopia, and enophthalmos, were analyzed and compared between the two groups. Patients in group A had significantly less wound complication than in group B (p < 0.05). In group A, there were no early or late wound complications after the operation. However, in group B, five patients had infection, the plate was exposed in eight of fourteen patients, and three patients had enophthalmos. Eight patients in group B underwent reoperation to correct their complications. Reconstruction of the orbital floor with a tensor fascia lata sling offers reliable support to the globe and prevents the ophthalmic complications associated with loss of orbital support. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

The fusion of craniofacial reconstruction and microsurgery: a functional and aesthetic approach.

Science.gov (United States)

Broyles, Justin M; Abt, Nicholas B; Shridharani, Sachin M; Bojovic, Branko; Rodriguez, Eduardo D; Dorafshar, Amir H

2014-10-01

Reconstruction of large, composite defects in the craniofacial region has evolved significantly over the past half century. During this time, there have been significant advances in craniofacial and microsurgical surgery. These contributions have often been in parallel; however, over the past 10 years, these two disciplines have begun to overlap more frequently, and the techniques of one have been used to advance the other. In the current review, the authors aim to describe the available options for free tissue reconstruction in craniofacial surgery. A review of microsurgical reconstructive options of aesthetic units within the craniofacial region was undertaken with attention directed toward surgeon flap preference. Anatomical areas analyzed included scalp, calvaria, forehead, frontal sinus, nose, maxilla and midface, periorbita, mandible, lip, and tongue. Although certain flaps such as the ulnar forearm flap and lateral circumflex femoral artery-based flaps were used in multiple reconstructive sites, each anatomical location possesses a unique array of flaps to maximize outcomes. Craniofacial surgery, like plastic surgery, has made tremendous advancements in the past 40 years. With innovations in technology, flap design, and training, microsurgery has become safer, faster, and more commonplace than at any time in history. Reconstructive microsurgery allows the surgeon to be creative in this approach, and free tissue transfer has become a mainstay of modern craniofacial reconstruction.

Breast Reconstruction Following Cancer Treatment.

Science.gov (United States)

Gerber, Bernd; Marx, Mario; Untch, Michael; Faridi, Andree

2015-08-31

About 8000 breast reconstructions after mastectomy are per - formed in Germany each year. It has become more difficult to advise patients because of the wide variety of heterologous and autologous techniques that are now available and because of changes in the recommendations about radiotherapy. This article is based on a review of pertinent articles (2005-2014) that were retrieved by a selective search employing the search terms "mastectomy" and "breast reconstruction." The goal of reconstruction is to achieve an oncologically safe and aestically satisfactory result for the patient over the long term. Heterologous, i.e., implant-based, breast reconstruction (IBR) and autologous breast reconstruction (ABR) are complementary techniques. Immediate reconstruction preserves the skin of the breast and its natural form and prevents the psychological trauma associated with mastectomy. If post-mastectomy radiotherapy (PMRT) is not indicated, implant-based reconstruction with or without a net/acellular dermal matrix (ADM) is a common option. Complications such as seroma formation, infection, and explantation are significantly more common when an ADM is used (15.3% vs. 5.4% ). If PMRT is performed, then the complication rate of implant-based breast reconstruction is 1 to 48% ; in particular, Baker grade III/IV capsular fibrosis occurs in 7 to 22% of patients, and the prosthesis must be explanted in 9 to 41% . Primary or, preferably, secondary autologous reconstruction is an alternative. The results of ABR are more stable over the long term, but the operation is markedly more complex. Autologous breast reconstruction after PMRT does not increase the risk of serious complications (20.5% vs. 17.9% without radiotherapy). No randomized controlled trials have yet been conducted to compare the reconstructive techniques with each other. If radiotherapy will not be performed, immediate reconstruction with an implant is recommended. On the other hand, if post-mastectomy radiotherapy

Defect reconstruction by non-destructive analyzing methods as basis for fracture mechanical evaluation

International Nuclear Information System (INIS)

Mueller, W.

1988-01-01

This document presents several techniques for the analysis and characterization of defects. The use of sector scan imaging systems is described, together with the Amplitude and Transit-Time Locus Curves (ALOK) searching and analyzing system. Information is also provided on ultrasonic holography and Line Synthetic Aperture Focussing Technique (LSAFT). (TEC)

Accelerating image reconstruction in dual-head PET system by GPU and symmetry properties.

Directory of Open Access Journals (Sweden)

Cheng-Ying Chou

Full Text Available Positron emission tomography (PET is an important imaging modality in both clinical usage and research studies. We have developed a compact high-sensitivity PET system that consisted of two large-area panel PET detector heads, which produce more than 224 million lines of response and thus request dramatic computational demands. In this work, we employed a state-of-the-art graphics processing unit (GPU, NVIDIA Tesla C2070, to yield an efficient reconstruction process. Our approaches ingeniously integrate the distinguished features of the symmetry properties of the imaging system and GPU architectures, including block/warp/thread assignments and effective memory usage, to accelerate the computations for ordered subset expectation maximization (OSEM image reconstruction. The OSEM reconstruction algorithms were implemented employing both CPU-based and GPU-based codes, and their computational performance was quantitatively analyzed and compared. The results showed that the GPU-accelerated scheme can drastically reduce the reconstruction time and thus can largely expand the applicability of the dual-head PET system.

NEGOTIATION OF IDENTITY: (RECONSTRUCTION AND (REPOSITIONING OF SELF THROUGH LANGUAGE LEARNING

Directory of Open Access Journals (Sweden)

Naho Isiki

2013-07-01

Full Text Available Abstract: Becoming competent in a language involves more than just academic success, but also multi-faceted aspects of self in a situated context. The core of the study is to explore a participant’s experience as a marginalized student in a Filipino American community and the trajectories of learning a foreign language over time and space. Narratives from the participant reflect his approach toward language learning (LL as well as his motivation behind language learning. This study highlights the impact of foreign language learning experience upon the participant’s conflict, negotiation, and transformation of identity. Following his positioning analysis, the paper closely looks at how evaluation by other Filipinos within the community contributes to the participant’s ongoing (reconstruction and negotiation of identity. How these evaluations encourage or impede his access to heritage language and culture is analyzed based on the participant’s use of reported speech. The paper explored whether or not LL can be a way of negotiating and gaining agency, as well as how LL helps a marginalized learner to choose where and how he wants to belong to. The paper also looks at how marginalization motivates language learning, through which the participant seeks to reposition himself. The study also examines how power relationship (marginalized student in a situated context plays a role in the process of negotiation of identity and meaning-making of self. Results from this study conclude that through experiences in foreign language learning as well as negotiating meanings for being a Japanese as a Foreign Language (JFL student, the participant gradually shifts to belong to a different community prior to his language learning experience in which he can practice agency and is no longer a marginalized member of his heritage community.

Permutationally invariant state reconstruction

DEFF Research Database (Denmark)

Moroder, Tobias; Hyllus, Philipp; Tóth, Géza

2012-01-01

Feasible tomography schemes for large particle numbers must possess, besides an appropriate data acquisition protocol, an efficient way to reconstruct the density operator from the observed finite data set. Since state reconstruction typically requires the solution of a nonlinear large-scale opti...... optimization, which has clear advantages regarding speed, control and accuracy in comparison to commonly employed numerical routines. First prototype implementations easily allow reconstruction of a state of 20 qubits in a few minutes on a standard computer.......-scale optimization problem, this is a major challenge in the design of scalable tomography schemes. Here we present an efficient state reconstruction scheme for permutationally invariant quantum state tomography. It works for all common state-of-the-art reconstruction principles, including, in particular, maximum...

Fast implementations of reconstruction-based scatter compensation in fully 3D SPECT image reconstruction

International Nuclear Information System (INIS)

Kadrmas, Dan J.; Karimi, Seemeen S.; Frey, Eric C.; Tsui, Benjamin M.W.

1998-01-01

Accurate scatter compensation in SPECT can be performed by modelling the scatter response function during the reconstruction process. This method is called reconstruction-based scatter compensation (RBSC). It has been shown that RBSC has a number of advantages over other methods of compensating for scatter, but using RBSC for fully 3D compensation has resulted in prohibitively long reconstruction times. In this work we propose two new methods that can be used in conjunction with existing methods to achieve marked reductions in RBSC reconstruction times. The first method, coarse-grid scatter modelling, significantly accelerates the scatter model by exploiting the fact that scatter is dominated by low-frequency information. The second method, intermittent RBSC, further accelerates the reconstruction process by limiting the number of iterations during which scatter is modelled. The fast implementations were evaluated using a Monte Carlo simulated experiment of the 3D MCAT phantom with 99m Tc tracer, and also using experimentally acquired data with 201 Tl tracer. Results indicated that these fast methods can reconstruct, with fully 3D compensation, images very similar to those obtained using standard RBSC methods, and in reconstruction times that are an order of magnitude shorter. Using these methods, fully 3D iterative reconstruction with RBSC can be performed well within the realm of clinically realistic times (under 10 minutes for 64x64x24 image reconstruction). (author)

Defect reconstruction by non-destructive analyzing methods as basis for fracture mechanical evaluation

Energy Technology Data Exchange (ETDEWEB)

Mueller, W

1988-12-31

This document presents several techniques for the analysis and characterization of defects. The use of sector scan imaging systems is described, together with the Amplitude and Transit-Time Locus Curves (ALOK) searching and analyzing system. Information is also provided on ultrasonic holography and Line Synthetic Aperture Focussing Technique (LSAFT). (TEC). 4 refs.

Winter-spring precipitation reconstructions from tree rings for northeast Mexico

Energy Technology Data Exchange (ETDEWEB)

Villanueva-Diaz, J.; Cerano-Paredes, J. [Instituto Nacional de Investigaciones Forestales y Agropecuarias, Centro Nacional de Investigacion Disciplinarioa en Relacion Agua, Suelo, Planta. Km 6.5 Margen Derecha del Canal Sacramento Gomez Palacio, Durango, 35140 (Mexico); Stahle, D.W.; Cleaveland, M.K. [Tree-Ring Laboratory, Department of Geosciences, University of Arkansas, fayetteville, Arkansas 72701 (United States); Luckman, B.H. [Department of Geography, University of Western Ontario, London, Ontario, N6A5C3 (Canada); Therrell, M.D. [Department of Environmental Sciences, University of Virginia, Charlottesville, VA 29904 (United States); Cornejo-Oviedo, E. [Departamento Forestal, Universidad Autonoma Agraria Antonio Narro, Saltillo, Coahuila (Mexico)

2007-07-15

The understanding of historic hydroclimatic variability is basic for planning proper management of limited water resources in northeastern Mexico. The objective of this study was to develop a network of tree-ring chronologies to reconstruct hydroclimate variability in northeastern Mexico and to analyze the influence of large-scale circulation patterns, such as ENSO. Precipitation sensitive tree-ring chronologies of Douglas-fir were developed in mountain ranges of the Sierra Madre Oriental and used to produce winter-spring precipitation reconstructions for central and southern Nuevo Leon, and southeastern Coahuila. The seasonal winter-spring precipitation reconstructions are 342 years long (1659-2001) for Saltillo, Coahuila and 602 years long (1400-2002) for central and southern Nuevo Leon. Both reconstructions show droughts in the 1810s, 1870s, 1890s, 1910s, and 1970s, and wet periods in the 1770s, 1930s, 1960s, and 1980s. Prior to 1800s the reconstructions are less similar. The impact of ENSO in northeastern Mexico (as measured by the Tropical Rainfall Index) indicated long-term instability of the Pacific equatorial teleconnection. Atmospheric circulation systems coming from higher latitudes (cold fronts or 'nortes') and others developed in the Gulf of Mexico (tropical storms, hurricanes) also influence the climatic conditions characterizing this region. The recent development of new and longer tree-ring chronologies for the region will contribute to a better understanding of the interannual and multidecadal climatic variability of northeastern Mexico.

A Multifactorial Analysis of Reconstruction Methods Applied After Total Gastrectomy

Directory of Open Access Journals (Sweden)

Oktay Büyükaşık

2010-12-01

Full Text Available Aim: The aim of this study was to evaluate the reconstruction methods applied after total gastrectomy in terms of postoperative symptomology and nutrition. Methods: This retrospective study was conducted on 31 patients who underwent total gastrectomy due to gastric cancer in 2. Clinic of General Surgery, SSK Ankara Training Hospital. 6 different reconstruction methods were used and analyzed in terms of age, sex and postoperative complications. One from esophagus and two biopsy specimens from jejunum were taken through upper gastrointestinal endoscopy from all cases, and late period morphological and microbiological changes were examined. Postoperative weight change, dumping symptoms, reflux esophagitis, solid/liquid dysphagia, early satiety, postprandial pain, diarrhea and anorexia were assessed. Results: Of 31 patients,18 were males and 13 females; the youngest one was 33 years old, while the oldest- 69 years old. It was found that reconstruction without pouch was performed in 22 cases and with pouch in 9 cases. Early satiety, postprandial pain, dumping symptoms, diarrhea and anemia were found most commonly in cases with reconstruction without pouch. The rate of bacterial colonization of the jejunal mucosa was identical in both groups. Reflux esophagitis was most commonly seen in omega esophagojejunostomy (EJ, while the least-in Roux-en-Y, Tooley and Tanner 19 EJ. Conclusion: Reconstruction with pouch performed after total gastrectomy is still a preferable method. (The Medical Bulletin of Haseki 2010; 48:126-31

Modeling fade patterns of nipple areola complex tattoos following breast reconstruction.

Science.gov (United States)

Levites, Heather A; Fourman, Mitchell S; Phillips, Brett T; Fromm, Indira M; Khan, Sami U; Dagum, Alexander B; Bui, Duc T

2014-12-01

Nipple-areolar complex (NAC) tattoos are an effective cosmetic solution for creating a finished look following breast reconstruction procedures. NAC tattoos are prone to significant fading, leading patients to seek revisions. This study was designed to quantify changes in NAC tattoo appearance over time. A total of 71 images of 39 patients were analyzed for NAC tattoo color and shape by 5 blinded medical student graders using a customized scoring system. Subsequently, each image was analyzed using ColorPic software (Iconico, New York, NY). Red/green/blue and hue/saturation/value color parameters were collected. Color quantities were normalized to the individual patient's skin tone to control for variability in lighting. Spearman correlations and nonlinear regressions were calculated utilizing GraphPad Prism 6.0 (GraphPad, La Jolla, CA). The length of time after tattoo placement inversely correlated with color score (P tattoo placement was also inversely correlated with all quantitative color parameters. Each color parameter fit a 1-phase exponential decay model. The decline in qualitative color and shape score agrees with clinical experience of tattoo quality declining over time. The color qualities of the tattoo approach those of the patient's skin over time, ultimately reaching a plateau. This can be modeled using a 1-phase decay equation. In practice, tattoo colors may be selected that compensate for the predictable changes that will occur. The results of this study will help optimize tattoo color and may alleviate the need for NAC tattoo revisions.

A novel algorithm of super-resolution image reconstruction based on multi-class dictionaries for natural scene

Science.gov (United States)

Wu, Wei; Zhao, Dewei; Zhang, Huan

2015-12-01

Super-resolution image reconstruction is an effective method to improve the image quality. It has important research significance in the field of image processing. However, the choice of the dictionary directly affects the efficiency of image reconstruction. A sparse representation theory is introduced into the problem of the nearest neighbor selection. Based on the sparse representation of super-resolution image reconstruction method, a super-resolution image reconstruction algorithm based on multi-class dictionary is analyzed. This method avoids the redundancy problem of only training a hyper complete dictionary, and makes the sub-dictionary more representatives, and then replaces the traditional Euclidean distance computing method to improve the quality of the whole image reconstruction. In addition, the ill-posed problem is introduced into non-local self-similarity regularization. Experimental results show that the algorithm is much better results than state-of-the-art algorithm in terms of both PSNR and visual perception.

Propagation of errors from the sensitivity image in list mode reconstruction

International Nuclear Information System (INIS)

Qi, Jinyi; Huesman, Ronald H.

2003-01-01

List mode image reconstruction is attracting renewed attention. It eliminates the storage of empty sinogram bins. However, a single back projection of all LORs is still necessary for the pre-calculation of a sensitivity image. Since the detection sensitivity is dependent on the object attenuation and detector efficiency, it must be computed for each study. Exact computation of the sensitivity image can be a daunting task for modern scanners with huge numbers of LORs. Thus, some fast approximate calculation may be desirable. In this paper, we theoretically analyze the error propagation from the sensitivity image into the reconstructed image. The theoretical analysis is based on the fixed point condition of the list mode reconstruction. The non-negativity constraint is modeled using the Kuhn-Tucker condition. With certain assumptions and the first order Taylor series approximation, we derive a closed form expression for the error in the reconstructed image as a function of the error in the sensitivity image. The result provides insights on what kind of error might be allowable in the sensitivity image. Computer simulations show that the theoretical results are in good agreement with the measured results

Theoretical evaluation of the detectability of random lesions in bayesian emission reconstruction

International Nuclear Information System (INIS)

Qi, Jinyi

2003-01-01

Detecting cancerous lesion is an important task in positron emission tomography (PET). Bayesian methods based on the maximum a posteriori principle (also called penalized maximum likelihood methods) have been developed to deal with the low signal to noise ratio in the emission data. Similar to the filter cut-off frequency in the filtered backprojection method, the prior parameters in Bayesian reconstruction control the resolution and noise trade-off and hence affect detectability of lesions in reconstructed images. Bayesian reconstructions are difficult to analyze because the resolution and noise properties are nonlinear and object-dependent. Most research has been based on Monte Carlo simulations, which are very time consuming. Building on the recent progress on the theoretical analysis of image properties of statistical reconstructions and the development of numerical observers, here we develop a theoretical approach for fast computation of lesion detectability in Bayesian reconstruction. The results can be used to choose the optimum hyperparameter for the maximum lesion detectability. New in this work is the use of theoretical expressions that explicitly model the statistical variation of the lesion and background without assuming that the object variation is (locally) stationary. The theoretical results are validated using Monte Carlo simulations. The comparisons show good agreement between the theoretical predications and the Monte Carlo results

Preliminary frequency-domain analysis for the reconstructed spatial resolution of muon tomography

Science.gov (United States)

Yu, B.; Zhao, Z.; Wang, X.; Wang, Y.; Wu, D.; Zeng, Z.; Zeng, M.; Yi, H.; Luo, Z.; Yue, X.; Cheng, J.

2014-11-01

Muon tomography is an advanced technology to non-destructively detect high atomic number materials. It exploits the multiple Coulomb scattering information of muon to reconstruct the scattering density image of the traversed object. Because of the statistics of muon scattering, the measurement error of system and the data incompleteness, the reconstruction is always accompanied with a certain level of interference, which will influence the reconstructed spatial resolution. While statistical noises can be reduced by extending the measuring time, system parameters determine the ultimate spatial resolution that one system can reach. In this paper, an effective frequency-domain model is proposed to analyze the reconstructed spatial resolution of muon tomography. The proposed method modifies the resolution analysis in conventional computed tomography (CT) to fit the different imaging mechanism in muon scattering tomography. The measured scattering information is described in frequency domain, then a relationship between the measurements and the original image is proposed in Fourier domain, which is named as "Muon Central Slice Theorem". Furthermore, a preliminary analytical expression of the ultimate reconstructed spatial is derived, and the simulations are performed for validation. While the method is able to predict the ultimate spatial resolution of a given system, it can also be utilized for the optimization of system design and construction.

Preliminary frequency-domain analysis for the reconstructed spatial resolution of muon tomography

International Nuclear Information System (INIS)

Yu, B.; Zhao, Z.; Wang, X.; Wang, Y.; Wu, D.; Zeng, Z.; Zeng, M.; Yi, H.; Luo, Z.; Yue, X.; Cheng, J.

2014-01-01

Muon tomography is an advanced technology to non-destructively detect high atomic number materials. It exploits the multiple Coulomb scattering information of muon to reconstruct the scattering density image of the traversed object. Because of the statistics of muon scattering, the measurement error of system and the data incompleteness, the reconstruction is always accompanied with a certain level of interference, which will influence the reconstructed spatial resolution. While statistical noises can be reduced by extending the measuring time, system parameters determine the ultimate spatial resolution that one system can reach. In this paper, an effective frequency-domain model is proposed to analyze the reconstructed spatial resolution of muon tomography. The proposed method modifies the resolution analysis in conventional computed tomography (CT) to fit the different imaging mechanism in muon scattering tomography. The measured scattering information is described in frequency domain, then a relationship between the measurements and the original image is proposed in Fourier domain, which is named as M uon Central Slice Theorem . Furthermore, a preliminary analytical expression of the ultimate reconstructed spatial is derived, and the simulations are performed for validation. While the method is able to predict the ultimate spatial resolution of a given system, it can also be utilized for the optimization of system design and construction

Graph-cut based discrete-valued image reconstruction.

Science.gov (United States)

Tuysuzoglu, Ahmet; Karl, W Clem; Stojanovic, Ivana; Castañòn, David; Ünlü, M Selim

2015-05-01

Efficient graph-cut methods have been used with great success for labeling and denoising problems occurring in computer vision. Unfortunately, the presence of linear image mappings has prevented the use of these techniques in most discrete-amplitude image reconstruction problems. In this paper, we develop a graph-cut based framework for the direct solution of discrete amplitude linear image reconstruction problems cast as regularized energy function minimizations. We first analyze the structure of discrete linear inverse problem cost functions to show that the obstacle to the application of graph-cut methods to their solution is the variable mixing caused by the presence of the linear sensing operator. We then propose to use a surrogate energy functional that overcomes the challenges imposed by the sensing operator yet can be utilized efficiently in existing graph-cut frameworks. We use this surrogate energy functional to devise a monotonic iterative algorithm for the solution of discrete valued inverse problems. We first provide experiments using local convolutional operators and show the robustness of the proposed technique to noise and stability to changes in regularization parameter. Then we focus on nonlocal, tomographic examples where we consider limited-angle data problems. We compare our technique with state-of-the-art discrete and continuous image reconstruction techniques. Experiments show that the proposed method outperforms state-of-the-art techniques in challenging scenarios involving discrete valued unknowns.

On an image reconstruction method for ECT

Science.gov (United States)

Sasamoto, Akira; Suzuki, Takayuki; Nishimura, Yoshihiro

2007-04-01

An image by Eddy Current Testing(ECT) is a blurred image to original flaw shape. In order to reconstruct fine flaw image, a new image reconstruction method has been proposed. This method is based on an assumption that a very simple relationship between measured data and source were described by a convolution of response function and flaw shape. This assumption leads to a simple inverse analysis method with deconvolution.In this method, Point Spread Function (PSF) and Line Spread Function(LSF) play a key role in deconvolution processing. This study proposes a simple data processing to determine PSF and LSF from ECT data of machined hole and line flaw. In order to verify its validity, ECT data for SUS316 plate(200x200x10mm) with artificial machined hole and notch flaw had been acquired by differential coil type sensors(produced by ZETEC Inc). Those data were analyzed by the proposed method. The proposed method restored sharp discrete multiple hole image from interfered data by multiple holes. Also the estimated width of line flaw has been much improved compared with original experimental data. Although proposed inverse analysis strategy is simple and easy to implement, its validity to holes and line flaw have been shown by many results that much finer image than original image have been reconstructed.

Designing experiments and analyzing data a model comparison perspective

CERN Document Server

Maxwell, Scott E

2013-01-01

Through this book's unique model comparison approach, students and researchers are introduced to a set of fundamental principles for analyzing data. After seeing how these principles can be applied in simple designs, students are shown how these same principles also apply in more complicated designs. Drs. Maxwell and Delaney believe that the model comparison approach better prepares students to understand the logic behind a general strategy of data analysis appropriate for various designs; and builds a stronger foundation, which allows for the introduction of more complex topics omitt

Incomplete projection reconstruction of computed tomography based on the modified discrete algebraic reconstruction technique

Science.gov (United States)

Yang, Fuqiang; Zhang, Dinghua; Huang, Kuidong; Gao, Zongzhao; Yang, YaFei

2018-02-01

Based on the discrete algebraic reconstruction technique (DART), this study aims to address and test a new improved algorithm applied to incomplete projection data to generate a high quality reconstruction image by reducing the artifacts and noise in computed tomography. For the incomplete projections, an augmented Lagrangian based on compressed sensing is first used in the initial reconstruction for segmentation of the DART to get higher contrast graphics for boundary and non-boundary pixels. Then, the block matching 3D filtering operator was used to suppress the noise and to improve the gray distribution of the reconstructed image. Finally, simulation studies on the polychromatic spectrum were performed to test the performance of the new algorithm. Study results show a significant improvement in the signal-to-noise ratios (SNRs) and average gradients (AGs) of the images reconstructed from incomplete data. The SNRs and AGs of the new images reconstructed by DART-ALBM were on average 30%-40% and 10% higher than the images reconstructed by DART algorithms. Since the improved DART-ALBM algorithm has a better robustness to limited-view reconstruction, which not only makes the edge of the image clear but also makes the gray distribution of non-boundary pixels better, it has the potential to improve image quality from incomplete projections or sparse projections.

Innovative Lime Pozzolana Renders for Reconstruction of Historical Buildings

International Nuclear Information System (INIS)

Vejmelkova, E.; Maca, P.; Konvalinka, P.; Cerny, R.

2011-01-01

Bulk density, matrix density, open porosity, compressive strength, bending strength, water sorptivity, moisture diffusivity, water vapor diffusion coefficient, thermal conductivity, specific heat capacity and thermal diffusivity of two innovative renovation renders on limepozzolana basis are analyzed. The obtained results are compared with reference lime plaster and two commercial renovation renders, and conclusions on the applicability of the particular renders in practical reconstruction works are drawn. (author)

Computer-assisted lung nodule volumetry from multi-detector row CT: Influence of image reconstruction parameters

International Nuclear Information System (INIS)

Honda, Osamu; Sumikawa, Hiromitsu; Johkoh, Takeshi; Tomiyama, Noriyuki; Mihara, Naoki; Inoue, Atsuo; Tsubamoto, Mitsuko; Natsag, Javzandulam; Hamada, Seiki; Nakamura, Hironobu

2007-01-01

Purpose: To investigate differences in volumetric measurement of pulmonary nodules caused by changing the reconstruction parameters for multi-detector row CT. Materials and methods: Thirty-nine pulmonary nodules less than 2 cm in diameter were examined by multi-slice CT. All nodules were solid, and located in the peripheral part of the lungs. The resultant 48 parameters images were reconstructed by changing slice thickness (1.25, 2.5, 3.75, or 5 mm), field of view (FOV: 10, 20, or 30 cm), algorithm (high-spatial frequency algorithm or low-spatial frequency algorithm) and reconstruction interval (reconstruction with 50% overlapping of the reconstructed slices or non-overlapping reconstruction). Volumetric measurements were calculated using commercially available software. The differences between nodule volumes were analyzed by the Kruskal-Wallis test and the Wilcoxon Signed-Ranks test. Results: The diameter of the nodules was 8.7 ± 2.7 mm on average, ranging from 4.3 to 16.4 mm. Pulmonary nodule volume did not change significantly with changes in slice thickness or FOV (p > 0.05), but was significantly larger with the high-spatial frequency algorithm than the low-spatial frequency algorithm (p < 0.05), except for one reconstruction parameter. The volumes determined by non-overlapping reconstruction were significantly larger than those of overlapping reconstruction (p < 0.05), except for a 1.25 mm thickness with 10 cm FOV with the high-spatial frequency algorithm, and 5 mm thickness. The maximum difference in measured volume was 16% on average between the 1.25 mm slice thickness/10 cm FOV/high-spatial frequency algorithm parameters and overlapping reconstruction. Conclusion: Volumetric measurements of pulmonary nodules differ with changes in the reconstruction parameters, with a tendency toward larger volumes in high-spatial frequency algorithm and non-overlapping reconstruction compared to the low-spatial frequency algorithm and overlapping reconstruction

Education in Emergencies and Early Reconstruction: UNICEF Interventions in Colombia, Liberia, and Southern Sudan

Science.gov (United States)

Beleli, Ozsel; Chang, Victoria; Feigelson, Michael J.; Kopel-Bailey, Jules A.; Maak, Sheila A.; Mnookin, Jacob P.; Nguyen, Thu H.; Salazar, Mariana; Sinderbrand, Joy E.; Tafoya, Simon N.

2007-01-01

Broad access to quality, child-friendly education in emergencies is a critical component of early reconstruction and development. As a class of graduate students at the Woodrow Wilson School of Public and International Affairs at Princeton University, our goal is to make a modest contribution to the field of education in emergencies by working…

BES-II fast data reconstruction

International Nuclear Information System (INIS)

Rong Gang; Zhang Jiawen; Guo Yiqing; Zhang Shaoqiang; Zhao Dixin

2002-01-01

The BES-II fast data reconstruction is reported. Based on PC FARM and/or a 'Distributed Clustered Linux PC System', BES-II fast data reconstruction system is set up. With this system the BES-II data can be fully reconstructed in about 20 minutes after data collection. It takes only 12 minutes to fully reconstruct 30000 events, collected with BES-II detector at BEPC Collider, with a P III-800 PC. The detector performance can be examined based on fully reconstructed data in about 20 minutes after data taking in the BES-II experiment

Analyzing How Emotion Awareness Influences Students' Motivation, Engagement, Self-Regulation and Learning Outcome

Science.gov (United States)

Arguedas, Marta; Daradoumis, Thanasis; Xhafa, Fatos

2016-01-01

Considering social and emotional competence in learning, "emotion awareness" aims to detect the emotions that students show during their learning interactions and make these emotions explicit to them. Being aware of their emotions, students become more conscious of their situation, what may prompt them to behavioral change. The main goal…

Research on Image Reconstruction Algorithms for Tuber Electrical Resistance Tomography System

Directory of Open Access Journals (Sweden)

Jiang Zili

2016-01-01

Full Text Available The application of electrical resistance tomography (ERT technology has been expanded to the field of agriculture, and the concept of TERT (Tuber Electrical Resistance Tomography is proposed. On the basis of the research on the forward and the inverse problems of the TERT system, a hybrid algorithm based on genetic algorithm is proposed, which can be used in TERT system to monitor the growth status of the plant tubers. The image reconstruction of TERT system is different from the conventional ERT system for two phase-flow measurement. Imaging of TERT needs more precision measurement and the conventional ERT cares more about the image reconstruction speed. A variety of algorithms are analyzed and optimized for the purpose of making them suitable for TERT system. For example: linear back projection, modified Newton-Raphson and genetic algorithm. Experimental results showed that the novel hybrid algorithm is superior to other algorithm and it can effectively improve the image reconstruction quality.

Managing the Dynamics of the Bologna Reforms: How Institutional Actors Re-Construct the Policy Framework

Science.gov (United States)

Veiga, Amélia; Neave, Guy

2015-01-01

How do the constituencies in higher education re-interpret Bologna's function with regard to the European Higher Education Area? This research examines how institutional actors re-construct the policy framework in the light of their own institutional agendas. Drawing on empirical data from a survey of academics, students and administrative and…

Students from Non-Dominant Linguistic Backgrounds Making Sense of Cosmology Visualizations

Science.gov (United States)

Buck Bracey, Zoë E.

2017-01-01

This article presents the results of exploratory research with community college students from non-dominant linguistic backgrounds (NDLB) in an introductory astronomy class as they collaborated to reconstruct dynamic cosmology visualizations through drawing. Data included student discourse during the drawing activity, post-activity interviews, and…

Clavicular bone tunnel malposition leads to early failures in coracoclavicular ligament reconstructions.

Science.gov (United States)

Cook, Jay B; Shaha, James S; Rowles, Douglas J; Bottoni, Craig R; Shaha, Steven H; Tokish, John M

2013-01-01

Modern techniques for the treatment of acromioclavicular (AC) joint dislocations have largely centered on free tendon graft reconstructions. Recent biomechanical studies have demonstrated that an anatomic reconstruction with 2 clavicular bone tunnels more closely matches the properties of native coracoclavicular (CC) ligaments than more traditional techniques. No study has analyzed tunnel position in regard to risk of early failure. To evaluate the effect of clavicular tunnel position in CC ligament reconstruction as a risk of early failure. Case series; Level of evidence, 4. A retrospective review was performed of a consecutive series of CC ligament reconstructions performed with 2 clavicular bone tunnels and a free tendon graft. The population was largely a young, active-duty military group of patients. Radiographs were analyzed for the maintenance of reduction and location of clavicular bone tunnels using a picture archiving and communication system. The distance from the lateral border of the clavicle to the center of each bone tunnel was divided by the total clavicular length to establish a ratio. Medical records were reviewed for operative details and functional outcome. Failure was defined as loss of intraoperative reduction. The overall failure rate was 28.6% (8/28) at an average of 7.4 weeks postoperatively. Comparison of bone tunnel position showed that medialized bone tunnels were a significant predictor for early loss of reduction for the conoid (a ratio of 0.292 vs 0.248; P = .012) and trapezoid bone tunnels (a ratio of 0.171 vs 0.128; P = .004); this correlated to an average of 7 to 9 mm more medial in the reconstructions that failed. Reconstructions performed with a conoid ratio of ≥0.30 were significantly more likely to fail (5/5, 100%) than were those performed lateral to a ratio of 0.30 (3/23, 13.0%) (P < .01). There were no failures when the conoid ratio was <0.25 (0/10, 0%). Conoid tunnel placement was also statistically significant for

Nipple-sparing mastectomy with immediate implant reconstruction: cosmetic outcomes and technical refinements.

Science.gov (United States)

Salgarello, Marzia; Visconti, Giuseppe; Barone-Adesi, Liliana

2010-11-01

Nipple-sparing mastectomy is gaining widespread popularity, as it could allow improved aesthetic outcome without increasing oncologic risk. To investigate the reconstructive issues experienced with immediate implant reconstruction, the authors reviewed the cosmetic outcomes of their series. The authors retrospectively analyzed the data on 33 cases of nipple-sparing mastectomy for both cancer and prophylaxis with immediate implant reconstruction using the submusculo-subfascial pocket. Cosmetic evaluation methods were clinical and photography-based assessments and a patient-satisfaction survey. The average follow-up period was 26.8 months. No nipple-areola complex cancer involvement was registered. The reconstructive outcomes ranged from good to excellent in 83 percent of the cases. Patients' satisfaction was high to very high, except in one patient who experienced total nipple-areola complex loss (one breast, 2.4 percent). Overall, early minor complications were registered in four breasts (9.5 percent) and late minor complications in five cases (12 percent). The authors' series suggest that nipple-sparing mastectomy is an option for carefully selected and screened patients. Larger studies with longer follow-up are needed, however. On the whole, the immediate one-stage implant reconstruction with hyperprojected anatomical gel implants represents a valid option. The skin incision algorithm proposed, which is based on the breast size, shape, and previous scars, might aid in the decision-making process to achieve satisfying results using this procedure. The radial approaches represent a good compromise between the oncologic and reconstructive procedures.

Preliminary attempt on maximum likelihood tomosynthesis reconstruction of DEI data

International Nuclear Information System (INIS)

Wang Zhentian; Huang Zhifeng; Zhang Li; Kang Kejun; Chen Zhiqiang; Zhu Peiping

2009-01-01

Tomosynthesis is a three-dimension reconstruction method that can remove the effect of superimposition with limited angle projections. It is especially promising in mammography where radiation dose is concerned. In this paper, we propose a maximum likelihood tomosynthesis reconstruction algorithm (ML-TS) on the apparent absorption data of diffraction enhanced imaging (DEI). The motivation of this contribution is to develop a tomosynthesis algorithm in low-dose or noisy circumstances and make DEI get closer to clinic application. The theoretical statistical models of DEI data in physics are analyzed and the proposed algorithm is validated with the experimental data at the Beijing Synchrotron Radiation Facility (BSRF). The results of ML-TS have better contrast compared with the well known 'shift-and-add' algorithm and FBP algorithm. (authors)

Visual reconstruction of Hampi Temple - Construed Graphically, Pictorially and Digitally

Directory of Open Access Journals (Sweden)

Meera Natampally

2014-05-01

Full Text Available The existing temple complex in Hampi, Karnataka, India was extensively studied, analyzed and documented. The complex was measured-drawn and digitized by plotting its edges and vertices using AutoCAD to generate 2d drawings. The graphic 2d elements developed were extended into 3 dimensional objects using Google sketch-up. The tool has been used to facilitate the visual re-construction to achieve the architecture of the temple in its original form. 3D virtual modelling / visual reconstruction helps us to visualize the structure in its original form giving a holistic picture of the Vijayanagara Empire in all its former glory. The project is interpreted graphically using Auto-CAD drawings, pictorially, digitally using Sketch-Up model and Kinect.

Analyzing the Psychological Symptoms of Students in Undergraduate Program in Elementary Mathematics Teaching

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Masal, Ercan; Koc, Mustafa; Colak, Tugba Seda; Takunyaci, Mithat

2013-01-01

The main purpose of this research is to analyse whether there is a difference or not in levels of having psychological symptoms of the students of undergraduate program in elementary mathematics teaching. Another aim of the research is to determine whether the levels of having psychological symptoms of the students differ or not regarding various…

Returning to sport after anterior cruciate ligament reconstruction in amateur sports men: a retrospective study.

Science.gov (United States)

Notarnicola, Angela; Maccagnano, Giuseppe; Barletta, Federico; Ascatigno, Leonardo; Astuto, Leopoldo; Panella, Antonio; Tafuri, Silvio; Moretti, Biagio

2016-01-01

According to the literature, 95% of professional athletes return to their sport after anterior cruciate ligament (ACL) reconstruction surgery. The main objective of this study was to verify the return to sport after ACL reconstruction in a homogenous group of amateur sportsmen and sportswomen in a series of Italian patients. We designed a retrospective study in which we analyzed the amateur sports patients operated for ACL reconstruction. We verified whether they had returned to sporting activities by comparing the pre- and post-operative Tegner activity scores. We then analyzed the average time to restart the sporting activity and the Lysholm and International Knee Documenting Committee (IKDC) scores. We analyzed 80 subjects: 47.5% restarted a sports activity, on average after eight months, with a significant reduction of their competitive level or physical commitment, as expressed by the Tegner activity score (pre-operative: 6.9; post-operative: 3.9; psport for international case studies and amateur sports is higher than our data. In our population we found the lack of information provided by the medical staff at discharge and follow-up. The assessment at a short-term follow up allowed us to verify that at the end of the post-surgical rehabilitation program the patients were uninformed about the timing and the ability to resume a sporting activity. An efficacious relationship between orthopedic doctor, physiotherapist and a doctor in motorial science may ensure proper treatment the patient after ACL reconstruction. It is important to guarantee the restarting of the sports activity to have a better quality of life in amateur sports. Level of evidence: V.

Volumetric quantification of lung nodules in CT with iterative reconstruction (ASiR and MBIR).

Science.gov (United States)

Chen, Baiyu; Barnhart, Huiman; Richard, Samuel; Robins, Marthony; Colsher, James; Samei, Ehsan

2013-11-01

Volume quantifications of lung nodules with multidetector computed tomography (CT) images provide useful information for monitoring nodule developments. The accuracy and precision of the volume quantification, however, can be impacted by imaging and reconstruction parameters. This study aimed to investigate the impact of iterative reconstruction algorithms on the accuracy and precision of volume quantification with dose and slice thickness as additional variables. Repeated CT images were acquired from an anthropomorphic chest phantom with synthetic nodules (9.5 and 4.8 mm) at six dose levels, and reconstructed with three reconstruction algorithms [filtered backprojection (FBP), adaptive statistical iterative reconstruction (ASiR), and model based iterative reconstruction (MBIR)] into three slice thicknesses. The nodule volumes were measured with two clinical software (A: Lung VCAR, B: iNtuition), and analyzed for accuracy and precision. Precision was found to be generally comparable between FBP and iterative reconstruction with no statistically significant difference noted for different dose levels, slice thickness, and segmentation software. Accuracy was found to be more variable. For large nodules, the accuracy was significantly different between ASiR and FBP for all slice thicknesses with both software, and significantly different between MBIR and FBP for 0.625 mm slice thickness with Software A and for all slice thicknesses with Software B. For small nodules, the accuracy was more similar between FBP and iterative reconstruction, with the exception of ASIR vs FBP at 1.25 mm with Software A and MBIR vs FBP at 0.625 mm with Software A. The systematic difference between the accuracy of FBP and iterative reconstructions highlights the importance of extending current segmentation software to accommodate the image characteristics of iterative reconstructions. In addition, a calibration process may help reduce the dependency of accuracy on reconstruction algorithms

Hybrid spectral CT reconstruction.

Directory of Open Access Journals (Sweden)

Darin P Clark

Full Text Available Current photon counting x-ray detector (PCD technology faces limitations associated with spectral fidelity and photon starvation. One strategy for addressing these limitations is to supplement PCD data with high-resolution, low-noise data acquired with an energy-integrating detector (EID. In this work, we propose an iterative, hybrid reconstruction technique which combines the spectral properties of PCD data with the resolution and signal-to-noise characteristics of EID data. Our hybrid reconstruction technique is based on an algebraic model of data fidelity which substitutes the EID data into the data fidelity term associated with the PCD reconstruction, resulting in a joint reconstruction problem. Within the split Bregman framework, these data fidelity constraints are minimized subject to additional constraints on spectral rank and on joint intensity-gradient sparsity measured between the reconstructions of the EID and PCD data. Following a derivation of the proposed technique, we apply it to the reconstruction of a digital phantom which contains realistic concentrations of iodine, barium, and calcium encountered in small-animal micro-CT. The results of this experiment suggest reliable separation and detection of iodine at concentrations ≥ 5 mg/ml and barium at concentrations ≥ 10 mg/ml in 2-mm features for EID and PCD data reconstructed with inherent spatial resolutions of 176 μm and 254 μm, respectively (point spread function, FWHM. Furthermore, hybrid reconstruction is demonstrated to enhance spatial resolution within material decomposition results and to improve low-contrast detectability by as much as 2.6 times relative to reconstruction with PCD data only. The parameters of the simulation experiment are based on an in vivo micro-CT experiment conducted in a mouse model of soft-tissue sarcoma. Material decomposition results produced from this in vivo data demonstrate the feasibility of distinguishing two K-edge contrast agents with

Hybrid spectral CT reconstruction

Science.gov (United States)

Clark, Darin P.

2017-01-01

Current photon counting x-ray detector (PCD) technology faces limitations associated with spectral fidelity and photon starvation. One strategy for addressing these limitations is to supplement PCD data with high-resolution, low-noise data acquired with an energy-integrating detector (EID). In this work, we propose an iterative, hybrid reconstruction technique which combines the spectral properties of PCD data with the resolution and signal-to-noise characteristics of EID data. Our hybrid reconstruction technique is based on an algebraic model of data fidelity which substitutes the EID data into the data fidelity term associated with the PCD reconstruction, resulting in a joint reconstruction problem. Within the split Bregman framework, these data fidelity constraints are minimized subject to additional constraints on spectral rank and on joint intensity-gradient sparsity measured between the reconstructions of the EID and PCD data. Following a derivation of the proposed technique, we apply it to the reconstruction of a digital phantom which contains realistic concentrations of iodine, barium, and calcium encountered in small-animal micro-CT. The results of this experiment suggest reliable separation and detection of iodine at concentrations ≥ 5 mg/ml and barium at concentrations ≥ 10 mg/ml in 2-mm features for EID and PCD data reconstructed with inherent spatial resolutions of 176 μm and 254 μm, respectively (point spread function, FWHM). Furthermore, hybrid reconstruction is demonstrated to enhance spatial resolution within material decomposition results and to improve low-contrast detectability by as much as 2.6 times relative to reconstruction with PCD data only. The parameters of the simulation experiment are based on an in vivo micro-CT experiment conducted in a mouse model of soft-tissue sarcoma. Material decomposition results produced from this in vivo data demonstrate the feasibility of distinguishing two K-edge contrast agents with a spectral

From geometry to algebra and vice versa: Realistic mathematics education principles for analyzing geometry tasks

Science.gov (United States)

Jupri, Al

2017-04-01

In this article we address how Realistic Mathematics Education (RME) principles, including the intertwinement and the reality principles, are used to analyze geometry tasks. To do so, we carried out three phases of a small-scale study. First we analyzed four geometry problems - considered as tasks inviting the use of problem solving and reasoning skills - theoretically in the light of the RME principles. Second, we tested two problems to 31 undergraduate students of mathematics education program and other two problems to 16 master students of primary mathematics education program. Finally, we analyzed student written work and compared these empirical to the theoretical results. We found that there are discrepancies between what we expected theoretically and what occurred empirically in terms of mathematization and of intertwinement of mathematical concepts from geometry to algebra and vice versa. We conclude that the RME principles provide a fruitful framework for analyzing geometry tasks that, for instance, are intended for assessing student problem solving and reasoning skills.

High-Speed Surface Reconstruction of Flying Birds Using Structured Light

Science.gov (United States)

Deetjen, Marc; Lentink, David

2017-11-01

Birds fly effectively through complex environments, and in order to understand the strategies that enable them to do so, we need to determine the shape and movement of their wings. Previous studies show that even small perturbations in wing shape have dramatic aerodynamic effects, but these shape changes have not been quantified automatically at high temporal and spatial resolutions. Hence, we developed a custom 3D surface mapping method which uses a high-speed camera to view a grid of stripes projected onto a flying bird. Because the light is binary rather than grayscale, and each frame is separately analyzed, this method can function at any frame rate with sufficient light. The method is automated, non-invasive, and able to measure a volume by simultaneously reconstructing from multiple views. We use this technique to reconstruct the 3D shape of the surface of a parrotlet during flapping flight at 3200 fps. We then analyze key dynamic parameters such as wing twist and angle of attack, and compute aerodynamic parameters such as lift and drag. While this novel system is designed to quantify bird wing shape and motion, it is adaptable for tracking other objects such as quickly deforming fish, especially those which are difficult to reconstruct using other 3D tracking methods. The presenter needs to leave by 3 pm on the final day of the conference (11/21) in order to make his flight. Please account for this in the scheduling if possible by scheduling the presentation earlier in the day or a different day.

Assessing and Analyzing the Performance of Students in College Science Laboratories.

Science.gov (United States)

Kyle, William C., Jr.; And Others

1979-01-01

The study investigated specific student behavior in introductory and advanced college laboratories in botany, chemistry, geology, physics, and zoology. Behaviors were observed, described, and classified with no effort made to induce change, detail underlying conditions, or identify correlates. (Author/RE)

Tomographic reconstruction by using FPSIRT (Fast Particle System Iterative Reconstruction Technique)

Energy Technology Data Exchange (ETDEWEB)

Moreira, Icaro Valgueiro M.; Melo, Silvio de Barros; Dantas, Carlos; Lima, Emerson Alexandre; Silva, Ricardo Martins; Cardoso, Halisson Alberdan C., E-mail: ivmm@cin.ufpe.br, E-mail: sbm@cin.ufpe.br, E-mail: rmas@cin.ufpe.br, E-mail: hacc@cin.ufpe.br, E-mail: ccd@ufpe.br, E-mail: eal@cin.ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

2015-07-01

The PSIRT (Particle System Iterative Reconstruction Technique) is a method of tomographic image reconstruction primarily designed to work with configurations suitable for industrial applications. A particle system is an optimization technique inspired in real physical systems that associates to the reconstructing material a set of particles with certain physical features, subject to a force eld, which can produce movement. The system constantly updates the set of particles by repositioning them in such a way as to approach the equilibrium. The elastic potential along a trajectory is a function of the difference between the attenuation coefficient in the current configuration and the corresponding input data. PSIRT has been successfully used to reconstruct simulated and real objects subject to sets of parallel and fanbeam lines in different angles, representing typical gamma-ray tomographic arrangements. One of PSIRT's limitation was its performance, too slow for real time scenarios. In this work, it is presented a reformulation in PSIRT's computational model, which is able to grant the new algorithm, the FPSIRT - Fast System Iterative Reconstruction Technique, a performance up to 200-time faster than PSIRT's. In this work a comparison of their application to real and simulated data from the HSGT, High Speed Gamma Tomograph, is presented. (author)

Tomographic reconstruction by using FPSIRT (Fast Particle System Iterative Reconstruction Technique)

International Nuclear Information System (INIS)

Moreira, Icaro Valgueiro M.; Melo, Silvio de Barros; Dantas, Carlos; Lima, Emerson Alexandre; Silva, Ricardo Martins; Cardoso, Halisson Alberdan C.

2015-01-01

The PSIRT (Particle System Iterative Reconstruction Technique) is a method of tomographic image reconstruction primarily designed to work with configurations suitable for industrial applications. A particle system is an optimization technique inspired in real physical systems that associates to the reconstructing material a set of particles with certain physical features, subject to a force eld, which can produce movement. The system constantly updates the set of particles by repositioning them in such a way as to approach the equilibrium. The elastic potential along a trajectory is a function of the difference between the attenuation coefficient in the current configuration and the corresponding input data. PSIRT has been successfully used to reconstruct simulated and real objects subject to sets of parallel and fanbeam lines in different angles, representing typical gamma-ray tomographic arrangements. One of PSIRT's limitation was its performance, too slow for real time scenarios. In this work, it is presented a reformulation in PSIRT's computational model, which is able to grant the new algorithm, the FPSIRT - Fast System Iterative Reconstruction Technique, a performance up to 200-time faster than PSIRT's. In this work a comparison of their application to real and simulated data from the HSGT, High Speed Gamma Tomograph, is presented. (author)

Influence of sampling interval and number of projections on the quality of SR-XFMT reconstruction

International Nuclear Information System (INIS)

Deng Biao; Yu Xiaohan; Xu Hongjie

2007-01-01

Synchrotron Radiation based X-ray Fluorescent Microtomography (SR-XFMT) is a nondestructive technique for detecting elemental composition and distribution inside a specimen with high spatial resolution and sensitivity. In this paper, computer simulation of SR-XFMT experiment is performed. The influence of the sampling interval and the number of projections on the quality of SR-XFMT image reconstruction is analyzed. It is found that the sampling interval has greater effect on the quality of reconstruction than the number of projections. (authors)

The evolving breast reconstruction

DEFF Research Database (Denmark)

Thomsen, Jørn Bo; Gunnarsson, Gudjon Leifur

2014-01-01

The aim of this editorial is to give an update on the use of the propeller thoracodorsal artery perforator flap (TAP/TDAP-flap) within the field of breast reconstruction. The TAP-flap can be dissected by a combined use of a monopolar cautery and a scalpel. Microsurgical instruments are generally...... not needed. The propeller TAP-flap can be designed in different ways, three of these have been published: (I) an oblique upwards design; (II) a horizontal design; (III) an oblique downward design. The latissimus dorsi-flap is a good and reliable option for breast reconstruction, but has been criticized...... for oncoplastic and reconstructive breast surgery and will certainly become an invaluable addition to breast reconstructive methods....

Reconstructing see-saw models

International Nuclear Information System (INIS)

Ibarra, Alejandro

2007-01-01

In this talk we discuss the prospects to reconstruct the high-energy see-saw Lagrangian from low energy experiments in supersymmetric scenarios. We show that the model with three right-handed neutrinos could be reconstructed in theory, but not in practice. Then, we discuss the prospects to reconstruct the model with two right-handed neutrinos, which is the minimal see-saw model able to accommodate neutrino observations. We identify the relevant processes to achieve this goal, and comment on the sensitivity of future experiments to them. We find the prospects much more promising and we emphasize in particular the importance of the observation of rare leptonic decays for the reconstruction of the right-handed neutrino masses

Limited-angle three-dimensional reconstructions using Fourier transform iterations and Radon transform iterations

International Nuclear Information System (INIS)

Tam, K.C.; Perez-Mendez, V.

1981-01-01

The principles of limited-angle reconstruction of space-limited objects using the concepts of allowed cone and missing cone in Fourier space are discussed. The distortion of a point source resulting from setting the Fourier components in the missing cone to zero has been calculated mathematically, and its bearing on the convergence of an iteration scheme involving Fourier transforms has been analyzed in detail. it was found that the convergence rate is fairly insensitive to the position of the point source within the boundary of the object, apart from an edge effect which tends to enhance some parts of the boundary in reconstructing the object. Another iteration scheme involving Radon transforms was introduced and compared to the Fourier transform method in such areas as root mean square error, stability with respect to noise, and computer reconstruction time

Limited-angle 3-D reconstructions using Fourier transform iterations and Radon transform iterations

International Nuclear Information System (INIS)

Tam, K.C.; Perez-Mendez, V.

1979-12-01

The principles of limited-angle reconstruction of space-limited objects using the concepts of allowed cone and missing cone in Fourier space are discussed. The distortion of a point source resulting from setting the Fourier components in the missing cone to zero was calculated mathematically, and its bearing on the convergence of an iteration scheme involving Fourier transforms was analyzed in detail. It was found that the convergence rate is fairly insensitive to the position of the point source within the boundary of the object, apart from an edge effect that tends to enhance some parts of the boundary in reconstructing the object. Another iteration scheme involving Radon transforms was introduced and compared to the Fourier transform method in such areas as root mean square error, stability with respect to noise, and computer reconstruction time. 8 figures, 2 tables

A volume of fluid method based on multidimensional advection and spline interface reconstruction

International Nuclear Information System (INIS)

Lopez, J.; Hernandez, J.; Gomez, P.; Faura, F.

2004-01-01

A new volume of fluid method for tracking two-dimensional interfaces is presented. The method involves a multidimensional advection algorithm based on the use of edge-matched flux polygons to integrate the volume fraction evolution equation, and a spline-based reconstruction algorithm. The accuracy and efficiency of the proposed method are analyzed using different tests, and the results are compared with those obtained recently by other authors. Despite its simplicity, the proposed method represents a significant improvement, and compares favorably with other volume of fluid methods as regards the accuracy and efficiency of both the advection and reconstruction steps

ANALYZING THE LEARNING STYLES OF JUNIOR HIGH SCHOOL STUDENTS AND THE IMPLICATION TO ENGLISH TEACHING: A CASE STUDY AT SMPN I DAGANGAN MADIUN

Directory of Open Access Journals (Sweden)

Zainal Arifin

2016-02-01

Full Text Available A language is probably the most difficult set of skills a person could ever struggle to learn. There is no easy way to master a language, particularly a language which is not our first language. In the process of learning a language particularly a second language, there are many variables that determine the success of learning; one of the variables is learning styles. In a class made up of various learning styles, it is always necessary for language teachers to identify, respect, and work on the diversity of the learners’ differences. The study investigated the diverse learning styles employed by ESL students of SMPN 1 Dagangan, Madiun Regency of East Java. The students were classified into three levels of competence: high, middle, and low level competence. They were also classified based on gender: males and females. A set of questionnaire was distributed to fifteen students. To get deeper interpretation on their learning styles, the students were also interviewed. The students’ learning style preferences were identified based on their levels of competence and gender in order to investigate their differences. The data was analyzed qualitatively. The findings revealed that the students’ learning styles can be categorized into visual, auditory, kinesthethic, tactile, individual, and group learners. The results of the study indicated that there were some differences in using learning styles by the students of high, middle and low levels of competence. A little difference was also found in male and female students in using learning styles. Thus, it is important for teachers to be aware of their students learning styles. It is clear then that one factor which can lead to the success of a language teaching-learning process is the match between students` learning styles and the teaching methods used by the teachers.

RAVE-a Detector-independent vertex reconstruction toolkit

Energy Technology Data Exchange (ETDEWEB)

Waltenberger, Wolfgang [Institute of High Energy Physics, Austrian Academy of Sciences A-1050 Vienna (Austria)], E-mail: walten@hephy.oeaw.ac.at; Mitaroff, Winfried; Moser, Fabian [Institute of High Energy Physics, Austrian Academy of Sciences A-1050 Vienna (Austria)

2007-10-21

A detector-independent toolkit for vertex reconstruction (RAVE) is being developed, along with a standalone framework (VERTIGO) for testing, analyzing and debugging. The core algorithms represent state of the art for geometric vertex finding and fitting by both linear (Kalman filter) and robust estimation methods. Main design goals are ease of use, flexibility for embedding into existing software frameworks, extensibility, and openness. The implementation is based on modern object-oriented techniques, is coded in C++ with interfaces for Java and Python, and follows an open-source approach. A beta release is available.

RAVE-a Detector-independent vertex reconstruction toolkit

International Nuclear Information System (INIS)

Waltenberger, Wolfgang; Mitaroff, Winfried; Moser, Fabian

2007-01-01

A detector-independent toolkit for vertex reconstruction (RAVE) is being developed, along with a standalone framework (VERTIGO) for testing, analyzing and debugging. The core algorithms represent state of the art for geometric vertex finding and fitting by both linear (Kalman filter) and robust estimation methods. Main design goals are ease of use, flexibility for embedding into existing software frameworks, extensibility, and openness. The implementation is based on modern object-oriented techniques, is coded in C++ with interfaces for Java and Python, and follows an open-source approach. A beta release is available

Integration of real-time 3D capture, reconstruction, and light-field display

Science.gov (United States)

Zhang, Zhaoxing; Geng, Zheng; Li, Tuotuo; Pei, Renjing; Liu, Yongchun; Zhang, Xiao

2015-03-01

Effective integration of 3D acquisition, reconstruction (modeling) and display technologies into a seamless systems provides augmented experience of visualizing and analyzing real objects and scenes with realistic 3D sensation. Applications can be found in medical imaging, gaming, virtual or augmented reality and hybrid simulations. Although 3D acquisition, reconstruction, and display technologies have gained significant momentum in recent years, there seems a lack of attention on synergistically combining these components into a "end-to-end" 3D visualization system. We designed, built and tested an integrated 3D visualization system that is able to capture in real-time 3D light-field images, perform 3D reconstruction to build 3D model of the objects, and display the 3D model on a large autostereoscopic screen. In this article, we will present our system architecture and component designs, hardware/software implementations, and experimental results. We will elaborate on our recent progress on sparse camera array light-field 3D acquisition, real-time dense 3D reconstruction, and autostereoscopic multi-view 3D display. A prototype is finally presented with test results to illustrate the effectiveness of our proposed integrated 3D visualization system.

Application of the fractional Fourier transform to image reconstruction in MRI.

Science.gov (United States)

Parot, Vicente; Sing-Long, Carlos; Lizama, Carlos; Tejos, Cristian; Uribe, Sergio; Irarrazaval, Pablo

2012-07-01

The classic paradigm for MRI requires a homogeneous B(0) field in combination with linear encoding gradients. Distortions are produced when the B(0) is not homogeneous, and several postprocessing techniques have been developed to correct them. Field homogeneity is difficult to achieve, particularly for short-bore magnets and higher B(0) fields. Nonlinear magnetic components can also arise from concomitant fields, particularly in low-field imaging, or intentionally used for nonlinear encoding. In any of these situations, the second-order component is key, because it constitutes the first step to approximate higher-order fields. We propose to use the fractional Fourier transform for analyzing and reconstructing the object's magnetization under the presence of quadratic fields. The fractional fourier transform provides a precise theoretical framework for this. We show how it can be used for reconstruction and for gaining a better understanding of the quadratic field-induced distortions, including examples of reconstruction for simulated and in vivo data. The obtained images have improved quality compared with standard Fourier reconstructions. The fractional fourier transform opens a new paradigm for understanding the MR signal generated by an object under a quadratic main field or nonlinear encoding. Copyright © 2011 Wiley Periodicals, Inc.

Uncut Esophagojejunostomy with Double Jejunal Pouch: An Alternative Reconstruction Method that Improves the Quality of Life of Patients after Total Gastrectomy.

Science.gov (United States)

Gong, Jia Qing; Cao, Yong Kuan; Zhang, Guo Hu; Wang, Pei Hong; Luo, Guo De

2017-04-01

Currently, there is no optimal digestive tract reconstruction technique well recognized by scholars after total gastrectomy. In this study, a new reconstruction method, which is modified from the classic Roux-en-Y procedure, an uncut jejunal esophageal anastomosis with double jejunal pouch (UJEA-DJP) was established, and its advantages for improving the quality of life of patients who undergo total gastrectomy were analyzed. Altogether 160 patients with gastric cancer enrolled in our center from September 2009 to March 2012 received radical D2 total gastrectomy. According to the reconstruction methods used, these patients were divided into three groups: UJEA-DJP (n = 63), Roux-en-Y (n = 45), and P-loop with Roux-en-Y esophagojejunostomy (P-RY; n = 52). The operation time for reconstruction, complications, prognostic nutritional index (PNI), and the Visick classification among the three groups were analyzed. We found that UJEA-DJP has advantages over Roux-en-Y and P-RY regarding the time of digestive tract reconstruction, incidence rates for long-term complications, postoperative nutritional index, body weight recovery, and the Visick classification for subjective feelings (p quality of life of patients after surgical procedure.

Perforator chimerism for the reconstruction of complex defects: A new chimeric free flap classification system.

Science.gov (United States)

Kim, Jeong Tae; Kim, Youn Hwan; Ghanem, Ali M

2015-11-01

Complex defects present structural and functional challenges to reconstructive surgeons. When compared to multiple free flaps or staged reconstruction, the use of chimeric flaps to reconstruct such defects have many advantages such as reduced number of operative procedures and donor site morbidity as well as preservation of recipient vessels. With increased popularity of perforator flaps, chimeric flaps' harvest and design has benefited from 'perforator concept' towards more versatile and better reconstruction solutions. This article discusses perforator based chimeric flaps and presents a practice based classification system that incorporates the perforator flap concept into "Perforator Chimerism". The authors analyzed a variety of chimeric patterns used in 31 consecutive cases to present illustrative case series and their new classification system. Accordingly, chimeric flaps are classified into four types. Type I: Classical Chimerism, Type II: Anastomotic Chimerism, Type III: Perforator Chimerism and Type IV Mixed Chimerism. Types I on specific source vessel anatomy whilst Type II requires microvascular anastomosis to create the chimeric reconstructive solution. Type III chimeric flaps utilizes the perforator concept to raise two components of tissues without microvascular anastomosis between them. Type IV chimeric flaps are mixed type flaps comprising any combination of Types I to III. Incorporation of the perforator concept in planning and designing chimeric flaps has allowed safe, effective and aesthetically superior reconstruction of complex defects. The new classification system aids reconstructive surgeons and trainees to understand chimeric flaps design, facilitating effective incorporation of this important reconstructive technique into the armamentarium of the reconstruction toolbox. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Spurious Additional Warming Reconstructed From Borehole Temperatures Corrected for the Effect of the Last Glacial Cycle

Science.gov (United States)

Šafanda, Jan

2018-03-01

Reconstructions of past ground surface temperature changes from temperature logs conducted in several hundred meter deep boreholes have proved to be a valuable independent source of information on climate variations over the last millennium. The reconstruction techniques have been evolving for more than two decades to extract optimally the climate signal of the last millennium contained in the temperature logs of different length performed in sites with different histories of the Last Glacial Cycle. This paper analyzes the method of the Last Glacial Cycle thermal effect removal from such borehole temperature profiles used by Beltrami et al. (2017, https://doi.org/10.1002/2016GL071317) in reconstructing the last 500 year history. I show that the reported results of additional warming in this period reconstructed from the corrected borehole data for North America are an artifact generated by the correction.

A Phase Current Reconstruction Approach for Three-Phase Permanent-Magnet Synchronous Motor Drive

Directory of Open Access Journals (Sweden)

Hao Yan

2016-10-01

Full Text Available Three-phase permanent-magnet synchronous motors (PMSMs are widely used in renewable energy applications such as wind power generation, tidal energy and electric vehicles owing to their merits such as high efficiency, high precision and high reliability. To reduce the cost and volume of the drive system, techniques of reconstructing three-phase current using a single current sensor have been reported for three-phase alternating current (AC control system using the power converts. In existing studies, the reconstruction precision is largely influenced by reconstructing dead zones on the Space Vector Pulse Width Modulation (SVPWM plane, which requires other algorithms to compensate either by modifying PWM modulation or by phase-shifting of the PWM signal. In this paper, a novel extended phase current reconstruction approach for PMSM drive is proposed. Six novel installation positions are obtained by analyzing the sampling results of the current paths between each two power switches. By arranging the single current sensor at these positions, the single current sensor is sampled during zero voltage vectors (ZVV without modifying the PWM signals. This proposed method can reconstruct the three-phase currents without any complex algorithms and is available in the sector boundary region and low modulation region. Finally, this method is validated by experiments.

Optimization of image reconstruction method for SPECT studies performed using [⁹⁹mTc-EDDA/HYNIC] octreotate in patients with neuroendocrine tumors.

Science.gov (United States)

Sowa-Staszczak, Anna; Lenda-Tracz, Wioletta; Tomaszuk, Monika; Głowa, Bogusław; Hubalewska-Dydejczyk, Alicja

2013-01-01

Somatostatin receptor scintigraphy (SRS) is a useful tool in the assessment of GEP-NET (gastroenteropancreatic neuroendocrine tumor) patients. The choice of appropriate settings of image reconstruction parameters is crucial in interpretation of these images. The aim of the study was to investigate how the GEP NET lesion signal to noise ratio (TCS/TCB) depends on different reconstruction settings for Flash 3D software (Siemens). SRS results of 76 randomly selected patients with confirmed GEP-NET were analyzed. For SPECT studies the data were acquired using standard clinical settings 3-4 h after the injection of 740 MBq 99mTc-[EDDA/HYNIC] octreotate. To obtain final images the OSEM 3D Flash reconstruction with different settings and FBP reconstruction were used. First, the TCS/TCB ratio in voxels was analyzed for different combinations of the number of subsets and the number of iterations of the OSEM 3D Flash reconstruction. Secondly, the same ratio was analyzed for different parameters of the Gaussian filter (with FWHM = 2-4 times greater from the pixel size). Also the influence of scatter correction on the TCS/TCB ratio was investigated. With increasing number of subsets and iterations, the increase of TCS/TCB ratio was observed. With increasing settings of Gauss [FWHM coefficient] filter, the decrease of TCS/TCB ratio was reported. The use of scatter correction slightly decreases the values of this ratio. OSEM algorithm provides a meaningfully better reconstruction of the SRS SPECT study as compared to the FBP technique. A high number of subsets improves image quality (images are smoother). Increasing number of iterations gives a better contrast and the shapes of lesions and organs are sharper. The choice of reconstruction parameters is a compromise between image qualitative appearance and its quantitative accuracy and should not be modified when comparing multiple studies of the same patient.

Pre-operative planning for mandibular reconstruction - A full digital planning workflow resulting in a patient specific reconstruction

Science.gov (United States)

2011-01-01

Objectives Reconstruction of large mandiblular defects following ablative oncologic surgery could be done by using vascularized bone transfer or, more often, primarily with simultaneous or delayed bone grafting, using load bearing reconstruction plates. Bending of these reconstruction plates is typically directed along the outer contour of the original mandible. Simultaneously or in a second operation vascularized or non-vascularized bone is fixed to the reconstruction plate. However, the prosthodontic-driven backward planning to ease bony reconstruction of the mandible in terms of dental rehabilitation using implant-retained overdentures might be an eligible solution. The purpose of this work was to develop, establish and clinically evaluate a novel 3D planning procedure for mandibular reconstruction. Materials and methods Three patients with tumors involving the mandible, which included squamous cell carcinoma in the floor of the mouth and keratocystic odontogenic tumor, were treated surgically by hemimandibulectomy. Results In primary alloplastic mandible reconstruction, shape and size of the reconstruction plate could be predefined and prebent prior to surgery. Clinical relevance This study provides modern treatment strategies for mandibular reconstruction. PMID:21968330

Ekofisk chalk: core measurements, stochastic reconstruction, network modeling and simulation

Energy Technology Data Exchange (ETDEWEB)

Talukdar, Saifullah

2002-07-01

This dissertation deals with (1) experimental measurements on petrophysical, reservoir engineering and morphological properties of Ekofisk chalk, (2) numerical simulation of core flood experiments to analyze and improve relative permeability data, (3) stochastic reconstruction of chalk samples from limited morphological information, (4) extraction of pore space parameters from the reconstructed samples, development of network model using pore space information, and computation of petrophysical and reservoir engineering properties from network model, and (5) development of 2D and 3D idealized fractured reservoir models and verification of the applicability of several widely used conventional up scaling techniques in fractured reservoir simulation. Experiments have been conducted on eight Ekofisk chalk samples and porosity, absolute permeability, formation factor, and oil-water relative permeability, capillary pressure and resistivity index are measured at laboratory conditions. Mercury porosimetry data and backscatter scanning electron microscope images have also been acquired for the samples. A numerical simulation technique involving history matching of the production profiles is employed to improve the relative permeability curves and to analyze hysteresis of the Ekofisk chalk samples. The technique was found to be a powerful tool to supplement the uncertainties in experimental measurements. Porosity and correlation statistics obtained from backscatter scanning electron microscope images are used to reconstruct microstructures of chalk and particulate media. The reconstruction technique involves a simulated annealing algorithm, which can be constrained by an arbitrary number of morphological parameters. This flexibility of the algorithm is exploited to successfully reconstruct particulate media and chalk samples using more than one correlation functions. A technique based on conditional simulated annealing has been introduced for exact reproduction of vuggy

Reconstruction of emission coefficients for a non-axisymmetric coupling arc by algebraic reconstruction technique

International Nuclear Information System (INIS)

Zhang Guangjun; Xiong Jun; Gao Hongming; Wu Lin

2011-01-01

A preliminary investigation of tomographic reconstruction of an asymmetric arc plasma has been carried out. The objective of this work aims at reconstructing emission coefficients of a non-axisymmetric coupling arc from measured intensities by means of an algebraic reconstruction technique (ART). In order to define the optimal experimental scheme for good quality with limited views, the dependence of the reconstruction quality on three configurations (four, eight, ten projection angles) are presented and discussed via a displaced Gaussian model. Then, the emission coefficients of a free burning arc are reconstructed by the ART with the ten-view configuration and an Abel inversion, respectively, and good agreement is obtained. Finally, the emission coefficient profiles of the coupling arc are successfully achieved with the ten-view configuration. The results show that the distribution of emission coefficient for the coupling arc is different from centrosymmetric shape. The ART is perfectly suitable for reconstructing emission coefficients of the coupling arc with the ten-view configuration, proving the feasibility and utility of the ART to characterize an asymmetric arc.

Linearized image reconstruction method for ultrasound modulated electrical impedance tomography based on power density distribution

International Nuclear Information System (INIS)

Song, Xizi; Xu, Yanbin; Dong, Feng

2017-01-01

Electrical resistance tomography (ERT) is a promising measurement technique with important industrial and clinical applications. However, with limited effective measurements, it suffers from poor spatial resolution due to the ill-posedness of the inverse problem. Recently, there has been an increasing research interest in hybrid imaging techniques, utilizing couplings of physical modalities, because these techniques obtain much more effective measurement information and promise high resolution. Ultrasound modulated electrical impedance tomography (UMEIT) is one of the newly developed hybrid imaging techniques, which combines electric and acoustic modalities. A linearized image reconstruction method based on power density is proposed for UMEIT. The interior data, power density distribution, is adopted to reconstruct the conductivity distribution with the proposed image reconstruction method. At the same time, relating the power density change to the change in conductivity, the Jacobian matrix is employed to make the nonlinear problem into a linear one. The analytic formulation of this Jacobian matrix is derived and its effectiveness is also verified. In addition, different excitation patterns are tested and analyzed, and opposite excitation provides the best performance with the proposed method. Also, multiple power density distributions are combined to implement image reconstruction. Finally, image reconstruction is implemented with the linear back-projection (LBP) algorithm. Compared with ERT, with the proposed image reconstruction method, UMEIT can produce reconstructed images with higher quality and better quantitative evaluation results. (paper)

Anatomic and histological characteristics of vagina reconstructed by McIndoe method

Directory of Open Access Journals (Sweden)

Kozarski Jefta

2009-01-01

Full Text Available Background/Aim. Congenital absence of vagina is known from ancient times of Greek. According to the literature data, incidence is 1/4 000 to 1/20 000. Treatment of this anomaly includes non-operative and operative procedures. McIndoe procedure uses split skin graft by Thiersch. The aim of this study was to establish anatomic and histological characteristics of vagina reconstructed by McIndoe method in Mayer Küster-Rockitansky Hauser (MKRH syndrome and compare them with normal vagina. Methods. The study included 21 patients of 18 and more years with congenital anomaly known as aplasio vaginae within the Mayer Küster-Rockitansky Hauser syndrome. The patients were operated on by the plastic surgeon using the McIndoe method. The study was a retrospective review of the data from the history of the disease, objective and gynecological examination and cytological analysis of native preparations of vaginal stain (Papanicolau. Comparatively, 21 females of 18 and more years with normal vaginas were also studied. All the subjects were divided into the groups R (reconstructed and C (control and the subgroups according to age up to 30 years (1 R, 1C, from 30 to 50 (2R, 2C, and over 50 (3R, 3C. Statistical data processing was performed by using the Student's t-test and Mann-Writney U-test. A value of p < 0.05 was considered statistically significant. Results. The results show that there are differences in the depth and the wideness of reconstructed vagina, but the obtained values are still in the range of normal ones. Cytological differences between a reconstructed and the normal vagina were found. Conclusion. A reconstructed vagina is smaller than the normal one regarding depth and width, but within the range of normal values. A split skin graft used in the reconstruction, keeps its own cytological, i.e. histological and, so, biological characteristics.

Soil life in reconstructed ecosystems: initial soil food web responses after rebuilding a forest soil profile for a climate change experiment

Science.gov (United States)

Paul T. Rygiewicz; Vicente J. Monleon; Elaine R. Ingham; Kendall J. Martin; Mark G. Johnson

2010-01-01

Disrupting ecosystem components, while transferring and reconstructing them for experiments can produce myriad responses. Establishing the extent of these biological responses as the system approaches a new equilibrium allows us more reliably to emulate comparable native systems. That is, the sensitivity of analyzing ecosystem processes in a reconstructed system is...

Identifying Students Struggling in Courses by Analyzing Exam Grades, Self-reported Measures and Study Activities

DEFF Research Database (Denmark)

Christensen, Bianca Clavio; Bemman, Brian; Knoche, Hendrik

2018-01-01

. In this paper, we present a set of instrument`s designed to identify at-risk undergraduate students in a Problem-based Learning (PBL) university, using an introductory programming course between two campus locations as a case study. Collectively, these instruments form the basis of a proposed learning ecosystem...... in the prediction model. Results of a multiple linear regression model found several significant assessment predictors related to how often students attempted self-guided course assignments and their self-reported programming experience, among others.......Technical educations often experience poor student performance and consequently high rates of attrition. Providing students with early feedback on their learning progress can assist students in self-study activities or in their decision-making process regarding a change in educational direction...

Cup Implant Planning Based on 2-D/3-D Radiographic Pelvis Reconstruction-First Clinical Results.

Science.gov (United States)

Schumann, Steffen; Sato, Yoshinobu; Nakanishi, Yuki; Yokota, Futoshi; Takao, Masaki; Sugano, Nobuhiko; Zheng, Guoyan

2015-11-01

In the following, we will present a newly developed X-ray calibration phantom and its integration for 2-D/3-D pelvis reconstruction and subsequent automatic cup planning. Two different planning strategies were applied and evaluated with clinical data. Two different cup planning methods were investigated: The first planning strategy is based on a combined pelvis and cup statistical atlas. Thereby, the pelvis part of the combined atlas is matched to the reconstructed pelvis model, resulting in an optimized cup planning. The second planning strategy analyzes the morphology of the reconstructed pelvis model to determine the best fitting cup implant. The first planning strategy was compared to 3-D CT-based planning. Digitally reconstructed radiographs of THA patients with differently severe pathologies were used to evaluate the accuracy of predicting the cup size and position. Within a discrepancy of one cup size, the size was correctly identified in 100% of the cases for Crowe type I datasets and in 77.8% of the cases for Crowe type II, III, and IV datasets. The second planning strategy was analyzed with respect to the eventually implanted cup size. In seven patients, the estimated cup diameter was correct within one cup size, while the estimation for the remaining five patients differed by two cup sizes. While both planning strategies showed the same prediction rate with a discrepancy of one cup size (87.5%), the prediction of the exact cup size was increased for the statistical atlas-based strategy (56%) in contrast to the anatomically driven approach (37.5%). The proposed approach demonstrated the clinical validity of using 2-D/3-D reconstruction technique for cup planning.

Technical basis for dose reconstruction

International Nuclear Information System (INIS)

Anspaugh, L.R.

1996-01-01

The purpose of this paper is to consider two general topics: Technical considerations of why dose-reconstruction studies should or should not be performed and methods of dose reconstruction. The first topic is of general and growing interest as the number of dose-reconstruction studies increases, and one asks the question whether it is necessary to perform a dose reconstruction for virtually every site at which, for example, the Department of Energy (DOE) has operated a nuclear-related facility. And there is the broader question of how one might logically draw the line at performing or not performing dose-reconstruction (radiological and chemical) studies for virtually every industrial complex in the entire country. The second question is also of general interest. There is no single correct way to perform a dose-reconstruction study, and it is important not to follow blindly a single method to the point that cheaper, faster, more accurate, and more transparent methods might not be developed and applied. 90 refs., 4 tabs

Technical basis for dose reconstruction

International Nuclear Information System (INIS)

Anspaugh, L.R.

1996-01-01

The purpose of this paper is to consider two general topics: technical considerations of why dose-reconstruction studies should or should not be performed and methods of dose reconstruction. The first topic is of general and growing interest as the number of dose-reconstruction studies increases, and one asks the question whether it is necessary to perform a dose reconstruction for virtually every site at which, for example, the Department of Energy (DOE) has operated a nuclear-related facility. And there is the broader question of how one might logically draw the line at performing or not performing dose-reconstruction (radiological and chemical) studies for virtually every industrial complex in the entire country. The second question is also of general interest. There is no single correct way to perform a dose-reconstruction study, and it is important not to follow blindly a single method to the point that cheaper, faster, more accurate, and more transparent methods might not be developed and applied

Impact of PET/CT image reconstruction methods and liver uptake normalization strategies on quantitative image analysis

Energy Technology Data Exchange (ETDEWEB)

Kuhnert, Georg; Sterzer, Sergej; Kahraman, Deniz; Dietlein, Markus; Drzezga, Alexander; Kobe, Carsten [University Hospital of Cologne, Department of Nuclear Medicine, Cologne (Germany); Boellaard, Ronald [VU University Medical Centre, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Scheffler, Matthias; Wolf, Juergen [University Hospital of Cologne, Lung Cancer Group Cologne, Department I of Internal Medicine, Center for Integrated Oncology Cologne Bonn, Cologne (Germany)

2016-02-15

In oncological imaging using PET/CT, the standardized uptake value has become the most common parameter used to measure tracer accumulation. The aim of this analysis was to evaluate ultra high definition (UHD) and ordered subset expectation maximization (OSEM) PET/CT reconstructions for their potential impact on quantification. We analyzed 40 PET/CT scans of lung cancer patients who had undergone PET/CT. Standardized uptake values corrected for body weight (SUV) and lean body mass (SUL) were determined in the single hottest lesion in the lung and normalized to the liver for UHD and OSEM reconstruction. Quantitative uptake values and their normalized ratios for the two reconstruction settings were compared using the Wilcoxon test. The distribution of quantitative uptake values and their ratios in relation to the reconstruction method used were demonstrated in the form of frequency distribution curves, box-plots and scatter plots. The agreement between OSEM and UHD reconstructions was assessed through Bland-Altman analysis. A significant difference was observed after OSEM and UHD reconstruction for SUV and SUL data tested (p < 0.0005 in all cases). The mean values of the ratios after OSEM and UHD reconstruction showed equally significant differences (p < 0.0005 in all cases). Bland-Altman analysis showed that the SUV and SUL and their normalized values were, on average, up to 60 % higher after UHD reconstruction as compared to OSEM reconstruction. OSEM and HD reconstruction brought a significant difference for SUV and SUL, which remained constantly high after normalization to the liver, indicating that standardization of reconstruction and the use of comparable SUV measurements are crucial when using PET/CT. (orig.)

Avascular necrosis in children with cerebral palsy after reconstructive hip surgery

Science.gov (United States)

Phillips, L.; Hesketh, K.; Schaeffer, E. K.; Andrade, J.; Farr, J.; Mulpuri, K.

2017-01-01

Abstract Purpose Progressive hip displacement is one of the most common orthopaedic pathologies in children with cerebral palsy (CP). Reconstructive hip surgery has become the standard treatment of care. Reported avascular necrosis (AVN) rates for hip reconstructive surgery in these patients vary widely in the literature. The purpose of this study is to identify the frequency and associated risk factors of AVN for reconstructive hip procedures. Methods A retrospective analysis was performed of 70 cases of reconstructive hip surgery in 47 children with CP, between 2009 and 2013. All 70 cases involved varus derotation osteotomy (VDRO), with 60% having combined VDRO and pelvic osteotomies (PO), and 21% requiring open reductions. Mean age at time of surgery was 8.82 years and 90% of patients were Gross Motor Function Classification System (GMFCS) 4 and 5. Radiographic dysplasia parameters were analysed at selected intervals, to a minimum of one year post-operatively. Severity of AVN was classified by Kruczynski's method. Bivar- iate statistical analysis was conducted using Chi-square test and Student's t-test. Results There were 19 (27%) noted cases of AVN, all radio- graphically identifiable within the first post-operative year. The majority of AVN cases (63%) were mild to moderate in severity. Pre-operative migration percentage (MP) (p = 0.0009) and post-operative change in MP (p = 0.002) were the most significant predictors of AVN. Other risk factors were: GMFCS level (p = 0.031), post-operative change in NSA (p = 0.02) and concomitant adductor tenotomy (0.028). Conclusion AVN was observed in 27% of patients. Severity of displacement correlates directly with AVN risk and we suggest that hip reconstruction, specifically VDRO, be performed early in the 'hip at risk' group to avoid this complication. PMID:29081846

Avascular necrosis in children with cerebral palsy after reconstructive hip surgery.

Science.gov (United States)

Phillips, L; Hesketh, K; Schaeffer, E K; Andrade, J; Farr, J; Mulpuri, K

2017-10-01

Progressive hip displacement is one of the most common orthopaedic pathologies in children with cerebral palsy (CP). Reconstructive hip surgery has become the standard treatment of care. Reported avascular necrosis (AVN) rates for hip reconstructive surgery in these patients vary widely in the literature. The purpose of this study is to identify the frequency and associated risk factors of AVN for reconstructive hip procedures. A retrospective analysis was performed of 70 cases of reconstructive hip surgery in 47 children with CP, between 2009 and 2013. All 70 cases involved varus derotation osteotomy (VDRO), with 60% having combined VDRO and pelvic osteotomies (PO), and 21% requiring open reductions. Mean age at time of surgery was 8.82 years and 90% of patients were Gross Motor Function Classification System (GMFCS) 4 and 5. Radiographic dysplasia parameters were analysed at selected intervals, to a minimum of one year post-operatively. Severity of AVN was classified by Kruczynski's method. Bivar- iate statistical analysis was conducted using Chi-square test and Student's t-test. There were 19 (27%) noted cases of AVN, all radio- graphically identifiable within the first post-operative year. The majority of AVN cases (63%) were mild to moderate in severity. Pre-operative migration percentage (MP) (p = 0.0009) and post-operative change in MP (p = 0.002) were the most significant predictors of AVN. Other risk factors were: GMFCS level (p = 0.031), post-operative change in NSA (p = 0.02) and concomitant adductor tenotomy (0.028). AVN was observed in 27% of patients. Severity of displacement correlates directly with AVN risk and we suggest that hip reconstruction, specifically VDRO, be performed early in the 'hip at risk' group to avoid this complication.

Three-dimensional ICT reconstruction

International Nuclear Information System (INIS)

Zhang Aidong; Li Ju; Chen Fa; Sun Lingxia

2005-01-01

The three-dimensional ICT reconstruction method is the hot topic of recent ICT technology research. In the context, qualified visual three-dimensional ICT pictures are achieved through multi-piece two-dimensional images accumulation by, combining with thresholding method and linear interpolation. Different direction and different position images of the reconstructed pictures are got by rotation and interception respectively. The convenient and quick method is significantly instructive to more complicated three-dimensional reconstruction of ICT images. (authors)

Three-dimensional ICT reconstruction

International Nuclear Information System (INIS)

Zhang Aidong; Li Ju; Chen Fa; Sun Lingxia

2004-01-01

The three-dimensional ICT reconstruction method is the hot topic of recent ICT technology research. In the context qualified visual three-dimensional ICT pictures are achieved through multi-piece two-dimensional images accumulation by order, combining with thresholding method and linear interpolation. Different direction and different position images of the reconstructed pictures are got by rotation and interception respectively. The convenient and quick method is significantly instructive to more complicated three-dimensional reconstruction of ICT images. (authors)

The completeness condition and source orbits for exact image reconstruction in 3D cone-beam CT

International Nuclear Information System (INIS)

Mao Xiping; Kang Kejun

1997-01-01

The completeness condition for exact image reconstruction in 3D cone-beam CT are carefully analyzed in theory, and discussions about some source orbits which fulfill the completeness condition are followed

Limited-angle tomography for analyzer-based phase-contrast x-ray imaging

International Nuclear Information System (INIS)

Majidi, Keivan; Wernick, Miles N; Brankov, Jovan G; Li, Jun; Muehleman, Carol

2014-01-01

Multiple-image radiography (MIR) is an analyzer-based phase-contrast x-ray imaging method, which is emerging as a potential alternative to conventional radiography. MIR simultaneously generates three planar parametric images containing information about scattering, refraction and attenuation properties of the object. The MIR planar images are linear tomographic projections of the corresponding object properties, which allows reconstruction of volumetric images using computed tomography (CT) methods. However, when acquiring a full range of linear projections around the tissue of interest is not feasible or the scanning time is limited, limited-angle tomography techniques can be used to reconstruct these volumetric images near the central plane, which is the plane that contains the pivot point of the tomographic movement. In this work, we use computer simulations to explore the applicability of limited-angle tomography to MIR. We also investigate the accuracy of reconstructions as a function of number of tomographic angles for a fixed total radiation exposure. We use this function to find an optimal range of angles over which data should be acquired for limited-angle tomography MIR (LAT-MIR). Next, we apply the LAT-MIR technique to experimentally acquired MIR projections obtained in a cadaveric human thumb study. We compare the reconstructed slices near the central plane to the same slices reconstructed by CT-MIR using the full angular view around the object. Finally, we perform a task-based evaluation of LAT-MIR performance for different numbers of angular views, and use template matching to detect cartilage in the refraction image near the central plane. We use the signal-to-noise ratio of this test as the detectability metric to investigate an optimum range of tomographic angles for detecting soft tissues in LAT-MIR. Both results show that there is an optimum range of angular view for data acquisition where LAT-MIR yields the best performance, comparable to CT

Limited-angle tomography for analyzer-based phase-contrast x-ray imaging

Science.gov (United States)

Majidi, Keivan; Wernick, Miles N.; Li, Jun; Muehleman, Carol; Brankov, Jovan G.

2014-07-01

Multiple-image radiography (MIR) is an analyzer-based phase-contrast x-ray imaging method, which is emerging as a potential alternative to conventional radiography. MIR simultaneously generates three planar parametric images containing information about scattering, refraction and attenuation properties of the object. The MIR planar images are linear tomographic projections of the corresponding object properties, which allows reconstruction of volumetric images using computed tomography (CT) methods. However, when acquiring a full range of linear projections around the tissue of interest is not feasible or the scanning time is limited, limited-angle tomography techniques can be used to reconstruct these volumetric images near the central plane, which is the plane that contains the pivot point of the tomographic movement. In this work, we use computer simulations to explore the applicability of limited-angle tomography to MIR. We also investigate the accuracy of reconstructions as a function of number of tomographic angles for a fixed total radiation exposure. We use this function to find an optimal range of angles over which data should be acquired for limited-angle tomography MIR (LAT-MIR). Next, we apply the LAT-MIR technique to experimentally acquired MIR projections obtained in a cadaveric human thumb study. We compare the reconstructed slices near the central plane to the same slices reconstructed by CT-MIR using the full angular view around the object. Finally, we perform a task-based evaluation of LAT-MIR performance for different numbers of angular views, and use template matching to detect cartilage in the refraction image near the central plane. We use the signal-to-noise ratio of this test as the detectability metric to investigate an optimum range of tomographic angles for detecting soft tissues in LAT-MIR. Both results show that there is an optimum range of angular view for data acquisition where LAT-MIR yields the best performance, comparable to CT

Geo-Sandbox: An Interactive Geoscience Training Tool with Analytics to Better Understand Student Problem Solving Approaches

Science.gov (United States)

Butt, N.; Pidlisecky, A.; Ganshorn, H.; Cockett, R.

2015-12-01

The software company 3 Point Science has developed three interactive learning programs designed to teach, test and practice visualization skills and geoscience concepts. A study was conducted with 21 geoscience students at the University of Calgary who participated in 2 hour sessions of software interaction and written pre and post-tests. Computer and SMART touch table interfaces were used to analyze user interaction, problem solving methods and visualization skills. By understanding and pinpointing user problem solving methods it is possible to reconstruct viewpoints and thought processes. This could allow us to give personalized feedback in real time, informing the user of problem solving tips and possible misconceptions.

Investigation of various reconstruction parameters for algebraic reconstruction technique in a newly developed chest digital tomosynthesis

International Nuclear Information System (INIS)

Lee, H.; Choi, S.; Kim, Y.-S.; Park, H.-S.; Seo, C.-W.; Kim, H.-J.; Lee, D.; Lee, Y.

2017-01-01

Chest digital tomosynthesis (CDT) is a promising new modality that provides 3D information by reconstructing limited projection views. CDT systems have been developed to improve the limitations of conventional radiography such as image degradation and low sensitivity. However, the development of reconstruction methods is challenging because of the limited projection views within various angular ranges. Optimization of reconstruction parameters for various reconsturction methods in CDT system also is needed. The purpose of this study was to investigate the feasibility of algebraic reconstruction technique (ART) method, and to evaluate the effect of the reconstruction parameters for our newly developed CDT system. We designed ART method with 41 projection views over an angular range of ±20°. To investigate the effect of reconstruction parameters, we measured the contrast-to-noise ratio (CNR), artifact spread function (ASF), and quality factor (QF) using LUNGMAN phantom included tumors. We found that the proper choice of reconstruction parameters such as relaxation parameter, initial guess, and number of iterations improved the quality of reconstructed images from the same projection views. Optimal values of ART relaxation parameter with uniform (UI) and back-projection (BP) initial guesses were 0.4 and 0.6, respectively. BP initial guess improved image quality in comparison with UI initial guess, in terms of providing a higher CNR and QF values with a faster speed. CNR and QF values improved with increasing number of iteration. Particularly, ART method with BP initial guess (when β = 0.6) after 3-terations provide satisfactory reconstructed image. In conclusion, the use of ART method with proper reconstruction parameters provided better image quality than FBP method as well as conventional radiography. These results indicated that the ART method with optimal reconstruction parameters could improve image quality for nodule detection using the CDT system.

Investigation of various reconstruction parameters for algebraic reconstruction technique in a newly developed chest digital tomosynthesis

Science.gov (United States)

Lee, H.; Choi, S.; Lee, D.; Kim, Y.-s.; Park, H.-S.; Lee, Y.; Seo, C.-W.; Kim, H.-J.

2017-08-01

Chest digital tomosynthesis (CDT) is a promising new modality that provides 3D information by reconstructing limited projection views. CDT systems have been developed to improve the limitations of conventional radiography such as image degradation and low sensitivity. However, the development of reconstruction methods is challenging because of the limited projection views within various angular ranges. Optimization of reconstruction parameters for various reconsturction methods in CDT system also is needed. The purpose of this study was to investigate the feasibility of algebraic reconstruction technique (ART) method, and to evaluate the effect of the reconstruction parameters for our newly developed CDT system. We designed ART method with 41 projection views over an angular range of ±20°. To investigate the effect of reconstruction parameters, we measured the contrast-to-noise ratio (CNR), artifact spread function (ASF), and quality factor (QF) using LUNGMAN phantom included tumors. We found that the proper choice of reconstruction parameters such as relaxation parameter, initial guess, and number of iterations improved the quality of reconstructed images from the same projection views. Optimal values of ART relaxation parameter with uniform (UI) and back-projection (BP) initial guesses were 0.4 and 0.6, respectively. BP initial guess improved image quality in comparison with UI initial guess, in terms of providing a higher CNR and QF values with a faster speed. CNR and QF values improved with increasing number of iteration. Particularly, ART method with BP initial guess (when β = 0.6) after 3-terations provide satisfactory reconstructed image. In conclusion, the use of ART method with proper reconstruction parameters provided better image quality than FBP method as well as conventional radiography. These results indicated that the ART method with optimal reconstruction parameters could improve image quality for nodule detection using the CDT system.

Study of the Efficacy of Cognitive Restructuring Teaching at Student\\'s Attribution Style and Academic Performance

Directory of Open Access Journals (Sweden)

Niloofar Mikaeili

2010-10-01

Full Text Available Objectives: One of the education ministry’s concerns in high schools is the problem of academic achievement. The researches have mentioned that student’s false attribution and absence of scholastic counseling service are the most important factors affecting student’s low performance and achievements. The main goal of this research was to study the rate of cognitive reconstructive effect on attribution style and girl students’ academic performance at high school in Khalkhal. Methods: Pre-test and post-test experimental designs with control group were used in this study. Thirty high school girl students were chosen randomly in 2 groups including 15 persons in experimental group and 15 persons in control group. Eight sessions of cognitive reconstructive counseling, like communal for experimental group, were held. Subjects were evaluated by attributive style inventory and school year average by per-test and post–test. The general hypothesis was “cognitive reconstructive education influence, students’ attribution style and academic performance”. Manava and independent groups’ t-test for testing hypotheses were used. Results: Analyses showed that cognitive reconstructive education increase internal, permanent and general attributions for positive events and decrease those attributions for negative events. Discussion: Cognitive reconstructive education increase students’ academic performance.

EEGNET: An Open Source Tool for Analyzing and Visualizing M/EEG Connectome.

Science.gov (United States)

Hassan, Mahmoud; Shamas, Mohamad; Khalil, Mohamad; El Falou, Wassim; Wendling, Fabrice

2015-01-01

The brain is a large-scale complex network often referred to as the "connectome". Exploring the dynamic behavior of the connectome is a challenging issue as both excellent time and space resolution is required. In this context Magneto/Electroencephalography (M/EEG) are effective neuroimaging techniques allowing for analysis of the dynamics of functional brain networks at scalp level and/or at reconstructed sources. However, a tool that can cover all the processing steps of identifying brain networks from M/EEG data is still missing. In this paper, we report a novel software package, called EEGNET, running under MATLAB (Math works, inc), and allowing for analysis and visualization of functional brain networks from M/EEG recordings. EEGNET is developed to analyze networks either at the level of scalp electrodes or at the level of reconstructed cortical sources. It includes i) Basic steps in preprocessing M/EEG signals, ii) the solution of the inverse problem to localize / reconstruct the cortical sources, iii) the computation of functional connectivity among signals collected at surface electrodes or/and time courses of reconstructed sources and iv) the computation of the network measures based on graph theory analysis. EEGNET is the unique tool that combines the M/EEG functional connectivity analysis and the computation of network measures derived from the graph theory. The first version of EEGNET is easy to use, flexible and user friendly. EEGNET is an open source tool and can be freely downloaded from this webpage: https://sites.google.com/site/eegnetworks/.

Volumetric quantification of lung nodules in CT with iterative reconstruction (ASiR and MBIR)

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Chen, Baiyu [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 (United States); Barnhart, Huiman [Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina 27705 (United States); Richard, Samuel [Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke University, Durham, North Carolina 27705 (United States); Robins, Marthony [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Colsher, James [Department of Radiology, Duke University, Durham, North Carolina 27705 (United States); Samei, Ehsan [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University, Durham, North Carolina 27705 (United States); Department of Physics, Department of Biomedical Engineering, and Department of Electronic and Computer Engineering, Duke University, Durham, North Carolina 27705 (United States)

2013-11-15

Purpose: Volume quantifications of lung nodules with multidetector computed tomography (CT) images provide useful information for monitoring nodule developments. The accuracy and precision of the volume quantification, however, can be impacted by imaging and reconstruction parameters. This study aimed to investigate the impact of iterative reconstruction algorithms on the accuracy and precision of volume quantification with dose and slice thickness as additional variables.Methods: Repeated CT images were acquired from an anthropomorphic chest phantom with synthetic nodules (9.5 and 4.8 mm) at six dose levels, and reconstructed with three reconstruction algorithms [filtered backprojection (FBP), adaptive statistical iterative reconstruction (ASiR), and model based iterative reconstruction (MBIR)] into three slice thicknesses. The nodule volumes were measured with two clinical software (A: Lung VCAR, B: iNtuition), and analyzed for accuracy and precision.Results: Precision was found to be generally comparable between FBP and iterative reconstruction with no statistically significant difference noted for different dose levels, slice thickness, and segmentation software. Accuracy was found to be more variable. For large nodules, the accuracy was significantly different between ASiR and FBP for all slice thicknesses with both software, and significantly different between MBIR and FBP for 0.625 mm slice thickness with Software A and for all slice thicknesses with Software B. For small nodules, the accuracy was more similar between FBP and iterative reconstruction, with the exception of ASIR vs FBP at 1.25 mm with Software A and MBIR vs FBP at 0.625 mm with Software A.Conclusions: The systematic difference between the accuracy of FBP and iterative reconstructions highlights the importance of extending current segmentation software to accommodate the image characteristics of iterative reconstructions. In addition, a calibration process may help reduce the dependency of

Volumetric quantification of lung nodules in CT with iterative reconstruction (ASiR and MBIR)

International Nuclear Information System (INIS)

Chen, Baiyu; Barnhart, Huiman; Richard, Samuel; Robins, Marthony; Colsher, James; Samei, Ehsan

2013-01-01

Purpose: Volume quantifications of lung nodules with multidetector computed tomography (CT) images provide useful information for monitoring nodule developments. The accuracy and precision of the volume quantification, however, can be impacted by imaging and reconstruction parameters. This study aimed to investigate the impact of iterative reconstruction algorithms on the accuracy and precision of volume quantification with dose and slice thickness as additional variables.Methods: Repeated CT images were acquired from an anthropomorphic chest phantom with synthetic nodules (9.5 and 4.8 mm) at six dose levels, and reconstructed with three reconstruction algorithms [filtered backprojection (FBP), adaptive statistical iterative reconstruction (ASiR), and model based iterative reconstruction (MBIR)] into three slice thicknesses. The nodule volumes were measured with two clinical software (A: Lung VCAR, B: iNtuition), and analyzed for accuracy and precision.Results: Precision was found to be generally comparable between FBP and iterative reconstruction with no statistically significant difference noted for different dose levels, slice thickness, and segmentation software. Accuracy was found to be more variable. For large nodules, the accuracy was significantly different between ASiR and FBP for all slice thicknesses with both software, and significantly different between MBIR and FBP for 0.625 mm slice thickness with Software A and for all slice thicknesses with Software B. For small nodules, the accuracy was more similar between FBP and iterative reconstruction, with the exception of ASIR vs FBP at 1.25 mm with Software A and MBIR vs FBP at 0.625 mm with Software A.Conclusions: The systematic difference between the accuracy of FBP and iterative reconstructions highlights the importance of extending current segmentation software to accommodate the image characteristics of iterative reconstructions. In addition, a calibration process may help reduce the dependency of

Entropy and transverse section reconstruction

International Nuclear Information System (INIS)

Gullberg, G.T.

1976-01-01

A new approach to the reconstruction of a transverse section using projection data from multiple views incorporates the concept of maximum entropy. The principle of maximizing information entropy embodies the assurance of minimizing bias or prejudice in the reconstruction. Using maximum entropy is a necessary condition for the reconstructed image. This entropy criterion is most appropriate for 3-D reconstruction of objects from projections where the system is underdetermined or the data are limited statistically. This is the case in nuclear medicine time limitations in patient studies do not yield sufficient projections

Breast reconstruction - natural tissue

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... flap; TRAM; Latissimus muscle flap with a breast implant; DIEP flap; DIEAP flap; Gluteal free flap; Transverse upper gracilis flap; TUG; Mastectomy - breast reconstruction with natural tissue; Breast cancer - breast reconstruction with natural tissue

Anesthesia Approach in Endovascular Aortic Reconstruction

Directory of Open Access Journals (Sweden)

Ayşin Alagöl

2013-03-01

Full Text Available Introduction: We have analyzed our initial results of our anesthesia techniques in our new-onset endovascular aortic reconstruction cases.Patients and Methods: The perioperative data of 15 elective and emergent endovascular aortic reconstruction cases that were operated in 2010-2011 were collected in a database. The choice of anesthesia was made by the risk factors, surgical team’s preferences, type and location of the aortic pathology and by the predicted operation duration. The data of local and general anesthesia cases were compared.Results: Thirteen (86.7% cases were male and 2 (13.3% female. Eleven patients were in ASA Class III. The demographic parameters, ASA classifications, concurrent diseases were similar in both groups. Thirteen (86.7% cases had infrarenal abdominal aortic aneurysm and 2 (13.3% had Type III aortic dissection. The diastolic arterial pressures were lower in general anesthesia group in 20th and 40th minutes’ measurements just like the mean arterial pressure measurements at the 40th, 100th minutes and during the deployment of the graft. Postoperative mortality occurred in 3 (20.0% patients and they all had general anesthesia and they were operated on emergency basis. Postoperative morbidity occurred in four patients that had general anesthesia (acute renal failure, multi-organ failure and pneumonia. The other patient had atrial fibrillation on the 1st postoperative day and was converted to sinus rhythm with amiodarone infusion.Conclusion: Edovascular aortic reconstruction procedures can safely be performed with both general and local anesthesia less invasively compared to open surgery. General anesthesia may be preferred for the better hemodynamic control.

Jini service to reconstruct tomographic data

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Knoll, Peter; Mirzaei, S.; Koriska, K.; Koehn, H.

2002-06-01

A number of imaging systems rely on the reconstruction of a 3- dimensional model from its projections through the process of computed tomography (CT). In medical imaging, for example magnetic resonance imaging (MRI), positron emission tomography (PET), and Single Computer Tomography (SPECT) acquire two-dimensional projections of a three dimensional projections of a three dimensional object. In order to calculate the 3-dimensional representation of the object, i.e. its voxel distribution, several reconstruction algorithms have been developed. Currently, mainly two reconstruct use: the filtered back projection(FBP) and iterative methods. Although the quality of iterative reconstructed SPECT slices is better than that of FBP slices, such iterative algorithms are rarely used for clinical routine studies because of their low availability and increased reconstruction time. We used Jini and a self-developed iterative reconstructions algorithm to design and implement a Jini reconstruction service. With this service, the physician selects the patient study from a database and a Jini client automatically discovers the registered Jini reconstruction services in the department's Intranet. After downloading the proxy object the this Jini service, the SPECT acquisition data are reconstructed. The resulting transaxial slices are visualized using a Jini slice viewer, which can be used for various imaging modalities.

A morphological study of the mandibular molar region using reconstructed helical computed tomographic images

International Nuclear Information System (INIS)

Tsuno, Hiroaki; Noguchi, Makoto; Noguchi, Akira; Yoshida, Keiko; Tachinami, Yasuharu

2010-01-01

This study investigated the morphological variance in the mandibular molar region using reconstructed helical computed tomographic (CT) images. In addition, we discuss the necessity of CT scanning as part of the preoperative assessment process for dental implantation, by comparing the results with the findings of panoramic radiography. Sixty patients examined using CT as part of the preoperative assessment for dental implantation were analyzed. Reconstructed CT images were used to evaluate the bone quality and cross-sectional bone morphology of the mandibular molar region. The mandibular cortical index (MCI) and X-ray density ratio of this region were assessed using panoramic radiography in order to analyze the correlation between the findings of the CT images and panoramic radiography. CT images showed that there was a decrease in bone quality in cases with high MCI. Cross-sectional CT images revealed that the undercuts on the lingual side in the highly radiolucent areas in the basal portion were more frequent than those in the alveolar portion. This study showed that three-dimensional reconstructed CT images can help to detect variances in mandibular morphology that might be missed by panoramic radiography. In conclusion, it is suggested that CT should be included as an important examination tool before dental implantation. (author)

Analyzing Student Perceptions on Translanguaging: A Case Study of a Puerto Rican University Classroom

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Rivera, Adrian J.; Mazak, Catherine M.

2017-01-01

Translanguaging in the classroom is gaining traction as a viable pedagogical choice. Often overlooked, though, are the students' attitudes in response to strategic classroom translanguaging. This study seeks to determine whether students' language attitudes influence their perceptions of an instructor's translingual pedagogy. The study took place…

Craniofacial reconstruction using patient-specific implants polyether ether ketone with computer-assisted planning.

Science.gov (United States)

Manrique, Oscar J; Lalezarzadeh, Frank; Dayan, Erez; Shin, Joseph; Buchbinder, Daniel; Smith, Mark

2015-05-01

Reconstruction of bony craniofacial defects requires precise understanding of the anatomic relationships. The ideal reconstructive technique should be fast as well as economical, with minimal donor-site morbidity, and provide a lasting and aesthetically pleasing result. There are some circumstances in which a patient's own tissue is not sufficient to reconstruct defects. The development of sophisticated software has facilitated the manufacturing of patient-specific implants (PSIs). The aim of this study was to analyze the utility of polyether ether ketone (PEEK) PSIs for craniofacial reconstruction. We performed a retrospective chart review from July 2009 to July 2013 in patients who underwent craniofacial reconstruction using PEEK-PSIs using a virtual process based on computer-aided design and computer-aided manufacturing. A total of 6 patients were identified. The mean age was 46 years (16-68 y). Operative indications included cancer (n = 4), congenital deformities (n = 1), and infection (n = 1). The mean surgical time was 3.7 hours and the mean hospital stay was 1.5 days. The mean surface area of the defect was 93.4 ± 43.26 cm(2), the mean implant cost was $8493 ± $837.95, and the mean time required to manufacture the implants was 2 weeks. No major or minor complications were seen during the 4-year follow-up. We found PEEK implants to be useful in the reconstruction of complex calvarial defects, demonstrating a low complication rate, good outcomes, and high patient satisfaction in this small series of patients. Polyether ether ketone implants show promising potential and warrant further study to better establish the role of this technology in cranial reconstruction.

BREAST RECONSTRUCTIONS AFTER BREAST CANCER TREATING

Directory of Open Access Journals (Sweden)

Erik Vrabič

2018-02-01

Full Text Available Background. Breasts are an important symbol of physical beauty, feminity, mothering and sexual desire through the entire history of mankind. Lost of the whole or part of the breast is functional and aesthetic disturbance for woman. It is understandable, that the woman, who is concerned over breast loss, is as appropriate as another person´s concern over the loss of a limb or other body part. Before the 1960, breast reconstruction was considered as a dangerous procedure and it was almost prohibited. Considering the psychological importance of the breast in modern society, the possibility of breast reconstruction for the woman about to undergo a mastectomy is a comforting alternative. We can perform breast reconstruction with autologous tissue (autologous reconstruction, with breast implants and combination of both methods. For autologous reconstruction we can use local tissue (local flaps, or tissue from distant parts of the body (free vascular tissue transfer. Tissue expansion must be performed first, in many cases of breast reconstructions with breast implants. Conclusions. Possibility of breast reconstruction made a big progress last 3 decades. Today we are able to reconstruct almost every defect of the breast and the entire breast. Breast reconstruction rise the quality of life for breast cancer patients. Breast reconstruction is a team work of experts from many medicine specialites. In Slovenia we can offer breast reconstruction for breast cancer patients in Ljubljana, where plastic surgeons from Clinical Department for Plastic Surgery and Burns cooperate with oncologic surgeons. Ten years ago a similar cooperation between plastic surgeons and surgeons of the Centre for Breast Diseases was established in Maribor.

Influencing Student Beliefs about the Role of the Civil Engineer in Society

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Nesbit, Susan E.; Sianchuk, Robert; Aleksejuniene, Jolanta; Kindiak, Rebecca

2012-01-01

This study suggests that community service learning experiences facilitate the reconstruction of civil engineering student beliefs about both the type of work performed by civil engineers and the broad impact of civil engineering knowledge. Further, the service learning experiences highlight for students 1) the importance of relationships between…

Neurofunctional systems. 3D reconstructions with correlated neuroimaging

International Nuclear Information System (INIS)

Kretschmann, H.J.; Fiekert, W.; Gerke, M.; Vogt, H.; Weirich, D.; Wesemann, M.; Weinrich, W.

1998-01-01

This book introduces, for the first time, computer-generated images of the neurofunctional systems of the human brain. These images are more accurate than drawings. The main views presented are of the medial lemniscus system, auditory system, visual system, basal ganglia, corticospinal system, and the limbic system. The arteries and sulci of the cerebral hemispheres are also illustrated by computer. These images provide a three-dimensional orientation of the intracranial space and help, for example, to assess vascular functional disturbance of the brain. Clinicians will find these images valuable for the spatial interpretation of magnetic resonance (MR), computed tomography (CT), and positron emission tomography (PET) images since many neurofunctional systems cannot be visualized as isolated structures in neuroimaging. Computer-assisted surface reconstructions of the neurofunctional systems and the cerebral arteries serve as a basis for constructing these computer-generated images. The surface reconstructions are anatomically realistic having been created from brain sections with minimal deformations. The method of computer graphics, known as ray tracing, produces digital images form these reconstructions. The computer-generated methods are explained. The computer-generated images are accompanied by illustrations and texts on neuroanatomy and clinical practice. The neurofunctional systems of the human brain are also shown in sections so that the reader can mentally reconstruct the neurofunctional systems, thus facilitating the transformation of information into textbooks and atlantes of MR and CT imaging. The aim of this book is acquaint the reader with the three-dimensional aspects of the neurofunctional systems and the cerebral arteries of the human brain using methods of computer graphics. Computer scientists and those interested in this technique are provided with basic neuroanatomic and neurofunctional information. Physicians will have a clearer understanding

Neurofunctional systems. 3D reconstructions with correlated neuroimaging

Energy Technology Data Exchange (ETDEWEB)

Kretschmann, H.J.; Fiekert, W.; Gerke, M.; Vogt, H.; Weirich, D.; Wesemann, M. [Medizinische Hochschule Hannover (Germany). Abt. Neuroanatomie; Weinrich, W. [Staedtisches Krankenhaus Nordstadt, Hannover (Germany). Abt. fuer Neurologie

1998-12-31

This book introduces, for the first time, computer-generated images of the neurofunctional systems of the human brain. These images are more accurate than drawings. The main views presented are of the medial lemniscus system, auditory system, visual system, basal ganglia, corticospinal system, and the limbic system. The arteries and sulci of the cerebral hemispheres are also illustrated by computer. These images provide a three-dimensional orientation of the intracranial space and help, for example, to assess vascular functional disturbance of the brain. Clinicians will find these images valuable for the spatial interpretation of magnetic resonance (MR), computed tomography (CT), and positron emission tomography (PET) images since many neurofunctional systems cannot be visualized as isolated structures in neuroimaging. Computer-assisted surface reconstructions of the neurofunctional systems and the cerebral arteries serve as a basis for constructing these computer-generated images. The surface reconstructions are anatomically realistic having been created from brain sections with minimal deformations. The method of computer graphics, known as ray tracing, produces digital images form these reconstructions. The computer-generated methods are explained. The computer-generated images are accompanied by illustrations and texts on neuroanatomy and clinical practice. The neurofunctional systems of the human brain are also shown in sections so that the reader can mentally reconstruct the neurofunctional systems, thus facilitating the transformation of information into textbooks and atlantes of MR and CT imaging. The aim of this book is acquaint the reader with the three-dimensional aspects of the neurofunctional systems and the cerebral arteries of the human brain using methods of computer graphics. Computer scientists and those interested in this technique are provided with basic neuroanatomic and neurofunctional information. Physicians will have a clearer understanding

Reconstruction of a ring applicator using CT imaging: impact of the reconstruction method and applicator orientation

International Nuclear Information System (INIS)

Hellebust, Taran Paulsen; Tanderup, Kari; Bergstrand, Eva Stabell; Knutsen, Bjoern Helge; Roeislien, Jo; Olsen, Dag Rune

2007-01-01

The purpose of this study is to investigate whether the method of applicator reconstruction and/or the applicator orientation influence the dose calculation to points around the applicator for brachytherapy of cervical cancer with CT-based treatment planning. A phantom, containing a fixed ring applicator set and six lead pellets representing dose points, was used. The phantom was CT scanned with the ring applicator at four different angles related to the image plane. In each scan the applicator was reconstructed by three methods: (1) direct reconstruction in each image (DR) (2) reconstruction in multiplanar reconstructed images (MPR) and (3) library plans, using pre-defined applicator geometry (LIB). The doses to the lead pellets were calculated. The relative standard deviation (SD) for all reconstruction methods was less than 3.7% in the dose points. The relative SD for the LIB method was significantly lower (p < 0.05) than for the DR and MPR methods for all but two points. All applicator orientations had similar dose calculation reproducibility. Using library plans for applicator reconstruction gives the most reproducible dose calculation. However, with restrictive guidelines for applicator reconstruction the uncertainties for all methods are low compared to other factors influencing the accuracy of brachytherapy

Delayed vaginal reconstruction in the fibrotic pelvis following radiation or previous reconstruction

International Nuclear Information System (INIS)

Berek, J.S.; Hacker, N.F.; Lagasse, L.D.; Smith, M.L.

1983-01-01

Vaginal reconstruction was performed in 14 patients who had developed vaginal stenosis secondary to extensive pelvic fibrosis after pelvic radiation therapy (12 patients) or prior vaginal reconstruction (2 patients). Sixteen procedures were performed using a split-thickness skin graft. All patients had satisfactory vaginal restoration, and 12 patients reported good vaginal function. No fistula developed as a result of the operative procedure, but one patient later developed a rectovaginal fistula resulting from tumor recurrence. Successful vaginal reconstruction can be achieved even years after initial therapy in patients who develop an obliterated vagina from previous radiation or surgery

Interpolated sagittal and coronal reconstruction of CT images in the screening of neck abnormalities

International Nuclear Information System (INIS)

Koga, Issei

1983-01-01

Recontructed sagittal and coronal images were analyzed for their usefulness during clinical applications and to determine the correct use of recontruction techniques. Recontructed stereoscopic images can be formed by continuous or interrupted image reconstruction using interpolation. This study showed that lesions less than 10 mm in diameter should be made continuously and recontructed with uninterrupted technique. However, 5 mm interrupted distances are acceptable for interpolated reconstruction except in cases of lesions less than 10 mm in diameter. Clinically, interpolated reconstruction is not adequated for semicircular lesions less than 10 mm. Blood vessels and linear lesions are good condiated for the application of interpolated recontruction. Reconstruction of images using interrupted interpolation is therefore recommended for screening and for demonstrating correct stereoscopic information, except cases of small lesions less than 10 mm in diameter. Results of this study underscore the fact that obscure information in transverse CT images should be routinely utilized by interporating recontruction techniques, if transverse images are not made continuously. Interpolated recontruction may be helpful in obtaining stereoscopic information. (author)

Delivering Breast Reconstruction Information to Patients: Women Report on Preferred Information Delivery Styles and Options.

Science.gov (United States)

Webb, Carmen; Sharma, Vishal; Temple-Oberle, Claire

2018-02-01

To discover missed opportunities for providing information to women undergoing breast reconstruction in an effort to decrease regret and improve patient education, teaching modalities, and satisfaction. Thirty- to 45-minute semi-structured interviews were conducted exploring patient experiences with information provision on breast reconstruction. Purposeful sampling was used to include women with a variety of reconstruction types at different time points along their recovery. Using grounded theory methodology, 2 independent reviewers analyzed the transcripts and generated thematic codes based on patient responses. BREAST-Q scores were also collected to compare satisfaction scores with qualitative responses. Patients were interested in a wide variety of topics related to breast reconstruction including the pros and cons of different options, nipple-sparing mastectomies, immediate breast reconstruction, oncological safety/monitoring and the impact of chemotherapy and radiotherapy, secondary procedures (balancing, nipple reconstruction), post-operative recovery, and long-term expectations. Patients valued accessing information from multiple sources, seeing numerous photographs, being guided to reliable information online, and having access to a frequently asked questions file or document. Information delivery via interaction with medical personnel and previously reconstructed patients was most appreciated. Compared with BREAST-Q scores for satisfaction with the plastic surgeon (mean: 95.7, range: 60-100), informational satisfaction scores were lower at 74.7 (50-100), confirming the informational gaps expressed by interviewees. Women having recently undergone breast reconstruction reported key deficiencies in information provided prior to surgery and identified preferred information delivery options. Addressing women's educational needs is important to achieve appropriate expectations and improve satisfaction.

Breast reconstruction following mastectomy: current status in Australia.

Science.gov (United States)

Sandelin, Kerstin; King, Elizabeth; Redman, Sally

2003-09-01

Although breast reconstruction provides some advantages for women following mastectomy, few Australian breast cancer patients currently receive reconstruction. In Australia, the routine provision of breast reconstruction will require the development of specific health service delivery models. The present paper reports an analysis of the provision of breast reconstruction in eight sites in Australia. A semi-structured telephone interview was conducted with 10 surgeons offering breast reconstruction as part of their practice, including nine breast or general surgeons and one plastic surgeon. Surgeons reported offering breast reconstruction to all women facing mastectomy; the proportion of women deciding to have breast reconstruction varied between sites with up to 50% of women having a reconstruction at some sites. Most sites offered three types of reconstruction. Two pathways emerged: either the breast surgeon performed the breast surgery in a team with the plastic surgeon who undertook the breast reconstruction or the breast surgeon provided both the breast surgery and the reconstruction. Considerable waiting times for breast reconstruction were reported in the public sector particularly for delayed reconstruction. Surgeons reported receiving training in breast reconstruction from plastic surgeons or from a breast surgery team that performed reconstructions; a number had been trained overseas. No audits of breast reconstruction were being undertaken. Breast reconstruction can be offered on a routine basis in Australia in both the private and public sectors. Women may be more readily able to access breast reconstruction when it is provided by a breast surgeon alone, but the range of reconstruction options may be more limited. If access to breast reconstruction is to be increased, there will be a need to: (i) develop effective models for the rural sector taking account of the lack of plastic surgeons; (ii) address waiting times for reconstruction surgery in the

Petz recovery versus matrix reconstruction

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Holzäpfel, Milan; Cramer, Marcus; Datta, Nilanjana; Plenio, Martin B.

2018-04-01

The reconstruction of the state of a multipartite quantum mechanical system represents a fundamental task in quantum information science. At its most basic, it concerns a state of a bipartite quantum system whose subsystems are subjected to local operations. We compare two different methods for obtaining the original state from the state resulting from the action of these operations. The first method involves quantum operations called Petz recovery maps, acting locally on the two subsystems. The second method is called matrix (or state) reconstruction and involves local, linear maps that are not necessarily completely positive. Moreover, we compare the quantities on which the maps employed in the two methods depend. We show that any state that admits Petz recovery also admits state reconstruction. However, the latter is successful for a strictly larger set of states. We also compare these methods in the context of a finite spin chain. Here, the state of a finite spin chain is reconstructed from the reduced states of a few neighbouring spins. In this setting, state reconstruction is the same as the matrix product operator reconstruction proposed by Baumgratz et al. [Phys. Rev. Lett. 111, 020401 (2013)]. Finally, we generalize both these methods so that they employ long-range measurements instead of relying solely on short-range correlations embodied in such local reduced states. Long-range measurements enable the reconstruction of states which cannot be reconstructed from measurements of local few-body observables alone and hereby we improve existing methods for quantum state tomography of quantum many-body systems.

Use of Social Media and an Online Survey to Discuss Complex Reconstructive Surgery: A Case of Upper Lip Reconstruction with 402 Responses from International Microsurgeons.

Science.gov (United States)

Kwon, Soo-Ha; Lee, Che-Hsiung; Hsu, Angela Ting-Wei; Shafarenko, Mark; Omar, Usama Farghaly; Tzou, Chieh-Han John; Roka-Palkovits, Julia; Beltrán P, Aldo G; Liakos, Dimitri; Chang, Tommy Nai-Jen

2018-02-02

The best reconstructive strategy for upper lip defects is still in debate. The purpose of this study was to analyze the decisions made by international microsurgeons, who were participated through online questionnaire, distributed by email and social media network. A case of a two-thirds upper lip oncologic defect was presented via an online questionnaire and 402 microsurgeons replied their treatment options. The data were then analyzed according to the geographic area, microsurgical fellowship, seniority, and subspecialty. All the data were analyzed using SPSS 22. A total of 27.7% of microsurgeons chose a free flap, while 72.3% chose a local/pedicle flap as their preferred method for reconstruction. The most common choice of free and local/pedicle flaps was radial forearm (73.6%) and Abbé (36.2%), respectively. The microsurgeons in Europe preferred local/pedicle flaps than free flap when compared with Middle/South America, Asia-Pacific, Africa and South Asia/Middle East (11.6% versus 50%, 43.4%, 29.3% and 27.3%, respectively, multivariant p  < 0.05). The microsurgeons with microsurgical fellowships preferred to use free flaps (32.9% versus 17.5%, multivariant p  = 0.021). There was no difference for the seniority and specialty of the microsurgeons. The online questionnaire is valuable and feasible for obtaining experts' opinions. This study provides a current global overview of surgical preferences for this common complicated clinical scenario. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Mandibular kinematics and maximum voluntary bite force following segmental resection of the mandible without or with reconstruction.

Science.gov (United States)

Linsen, Sabine S; Oikonomou, Annina; Martini, Markus; Teschke, Marcus

2018-05-01

The purpose was to analyze mandibular kinematics and maximum voluntary bite force in patients following segmental resection of the mandible without and with reconstruction (autologous bone, alloplastic total temporomandibular joint replacement (TMJ TJR)). Subjects operated from April 2002 to August 2014 were enrolled in the study. Condylar (CRoM) and incisal (InRoM) range of motion and deflection during opening, condylar retrusion, incisal lateral excursion, mandibular rotation angle during opening, and maximum voluntary bite force were determined on the non-affected site and compared between groups. Influence of co-factors (defect size, soft tissue deficit, neck dissection, radiotherapy, occlusal contact zones (OCZ), and time) was determined. Twelve non-reconstructed and 26 reconstructed patients (13 autologous, 13 TMJ TJR) were included in the study. InRoM opening and bite force were significantly higher (P ≤ .024), and both condylar and incisal deflection during opening significantly lower (P ≤ .027) in reconstructed patients compared with non-reconstructed. Differences between the autologous and the TMJ TJR group were statistically not significant. Co-factors defect size, soft tissue deficit, and neck dissection had the greatest impact on kinematics and number of OCZs on bite force. Reconstructed patients (both autologous and TMJ TJR) have better overall function than non-reconstructed patients. Reconstruction of segmental mandibular resection has positive effects on mandibular function. TMJ TJR seems to be a suitable technique for the reconstruction of mandibular defects including the TMJ complex.

Increasing Student Engagement by Using Morrowind to Analyze Choices and Consequences

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Kadakia, Maya

2005-01-01

During the 2004-2005 school year, Maya Kadakia conducted a pilot study of her master's project which focuses on how student engagement is affected by a curriculum that incorporates popular culture. She created a Language Arts unit which incorporates the video game Morrowhid. Maya teaches seventh grade Language Arts and Social Studies at a diverse…

Joint reconstruction of activity and attenuation in Time-of-Flight PET: A Quantitative Analysis.

Science.gov (United States)

Rezaei, Ahmadreza; Deroose, Christophe M; Vahle, Thomas; Boada, Fernando; Nuyts, Johan

2018-03-01

Joint activity and attenuation reconstruction methods from time of flight (TOF) positron emission tomography (PET) data provide an effective solution to attenuation correction when no (or incomplete/inaccurate) information on the attenuation is available. One of the main barriers limiting their use in clinical practice is the lack of validation of these methods on a relatively large patient database. In this contribution, we aim at validating the activity reconstructions of the maximum likelihood activity reconstruction and attenuation registration (MLRR) algorithm on a whole-body patient data set. Furthermore, a partial validation (since the scale problem of the algorithm is avoided for now) of the maximum likelihood activity and attenuation reconstruction (MLAA) algorithm is also provided. We present a quantitative comparison of the joint reconstructions to the current clinical gold-standard maximum likelihood expectation maximization (MLEM) reconstruction with CT-based attenuation correction. Methods: The whole-body TOF-PET emission data of each patient data set is processed as a whole to reconstruct an activity volume covering all the acquired bed positions, which helps to reduce the problem of a scale per bed position in MLAA to a global scale for the entire activity volume. Three reconstruction algorithms are used: MLEM, MLRR and MLAA. A maximum likelihood (ML) scaling of the single scatter simulation (SSS) estimate to the emission data is used for scatter correction. The reconstruction results are then analyzed in different regions of interest. Results: The joint reconstructions of the whole-body patient data set provide better quantification in case of PET and CT misalignments caused by patient and organ motion. Our quantitative analysis shows a difference of -4.2% (±2.3%) and -7.5% (±4.6%) between the joint reconstructions of MLRR and MLAA compared to MLEM, averaged over all regions of interest, respectively. Conclusion: Joint activity and attenuation

Ancestral sequence reconstruction in primate mitochondrial DNA: compositional bias and effect on functional inference.

Science.gov (United States)

Krishnan, Neeraja M; Seligmann, Hervé; Stewart, Caro-Beth; De Koning, A P Jason; Pollock, David D

2004-10-01

Reconstruction of ancestral DNA and amino acid sequences is an important means of inferring information about past evolutionary events. Such reconstructions suggest changes in molecular function and evolutionary processes over the course of evolution and are used to infer adaptation and convergence. Maximum likelihood (ML) is generally thought to provide relatively accurate reconstructed sequences compared to parsimony, but both methods lead to the inference of multiple directional changes in nucleotide frequencies in primate mitochondrial DNA (mtDNA). To better understand this surprising result, as well as to better understand how parsimony and ML differ, we constructed a series of computationally simple "conditional pathway" methods that differed in the number of substitutions allowed per site along each branch, and we also evaluated the entire Bayesian posterior frequency distribution of reconstructed ancestral states. We analyzed primate mitochondrial cytochrome b (Cyt-b) and cytochrome oxidase subunit I (COI) genes and found that ML reconstructs ancestral frequencies that are often more different from tip sequences than are parsimony reconstructions. In contrast, frequency reconstructions based on the posterior ensemble more closely resemble extant nucleotide frequencies. Simulations indicate that these differences in ancestral sequence inference are probably due to deterministic bias caused by high uncertainty in the optimization-based ancestral reconstruction methods (parsimony, ML, Bayesian maximum a posteriori). In contrast, ancestral nucleotide frequencies based on an average of the Bayesian set of credible ancestral sequences are much less biased. The methods involving simpler conditional pathway calculations have slightly reduced likelihood values compared to full likelihood calculations, but they can provide fairly unbiased nucleotide reconstructions and may be useful in more complex phylogenetic analyses than considered here due to their speed and

Multilocus phylogeny reconstruction: new insights into the evolutionary history of the genus Petunia.

Science.gov (United States)

Reck-Kortmann, Maikel; Silva-Arias, Gustavo Adolfo; Segatto, Ana Lúcia Anversa; Mäder, Geraldo; Bonatto, Sandro Luis; de Freitas, Loreta Brandão

2014-12-01

The phylogeny of Petunia species has been difficult to resolve, primarily due to the recent diversification of the genus. Several studies have included molecular data in phylogenetic reconstructions of this genus, but all of them have failed to include all taxa and/or analyzed few genetic markers. In the present study, we employed the most inclusive genetic and taxonomic datasets for the genus, aiming to reconstruct the evolutionary history of Petunia based on molecular phylogeny, biogeographic distribution, and character evolution. We included all 20 Petunia morphological species or subspecies in these analyses. Based on nine nuclear and five plastid DNA markers, our phylogenetic analysis reinforces the monophyly of the genus Petunia and supports the hypothesis that the basal divergence is more related to the differentiation of corolla tube length, whereas the geographic distribution of species is more related to divergences within these main clades. Ancestral area reconstructions suggest the Pampas region as the area of origin and earliest divergence in Petunia. The state reconstructions suggest that the ancestor of Petunia might have had a short corolla tube and a bee pollination floral syndrome. Copyright © 2014 Elsevier Inc. All rights reserved.

Breast Reconstruction After Solid Organ Transplant.

Science.gov (United States)

Koonce, Stephanie L; Giles, Brian; McLaughlin, Sarah A; Perdikis, Galen; Waldorf, James; Lemaine, Valerie; TerKonda, Sarvam

2015-09-01

Solid organ transplant patients frequently develop posttransplant malignancies including breast cancer. They may desire breast reconstruction after mastectomy, which could potentially be complicated by their transplant status, immunosuppressive regimen, and previous operations. We review our experience with patients who have undergone solid organ transplant and subsequent breast reconstruction after mastectomy After institutional review board approval, we queried our prospective breast reconstruction and solid organ transplant databases for corresponding patients. Inclusion criteria comprised breast reconstruction after solid organ transplant. A chart review was conducted of identified patients. Seventeen patients were identified: 1 pulmonary transplant, 4 cardiac transplants, 2 liver transplants, 1 pancreas transplant, 2 combined kidney/pancreas transplants, and 7 kidney transplants. Indications for mastectomy included posttransplant malignancy and prophylaxis. Median time from transplant to completion of reconstruction was 186 months (range, 11-336 months). Median age at transplant was 34.5 years (range, 21-65 years) with the median age of the patients at reconstructive surgery 51.5 years (range, 34-71 years). Median body mass index was 25.3 (range, 21.3-46.5). No significant complications were noted after reconstructive surgery. All patients were on full immunosuppression at time of reconstruction. Breast reconstruction is a viable option for transplant patients after mastectomy and should not be refused based on their transplant status. Close coordination with the transplant team and careful preoperative planning is essential for optimal outcomes.

Adaptive enhancement of optical fringe patterns by selective reconstruction using FABEMD algorithm and Hilbert spiral transform.

Science.gov (United States)

Trusiak, Maciej; Patorski, Krzysztof; Wielgus, Maciej

2012-10-08

Presented method for fringe pattern enhancement has been designed for processing and analyzing low quality fringe patterns. It uses a modified fast and adaptive bidimensional empirical mode decomposition (FABEMD) for the extraction of bidimensional intrinsic mode functions (BIMFs) from an interferogram. Fringe pattern is then selectively reconstructed (SR) taking the regions of selected BIMFs with high modulation values only. Amplitude demodulation and normalization of the reconstructed image is conducted using the spiral phase Hilbert transform (HS). It has been tested using computer generated interferograms and real data. The performance of the presented SR-FABEMD-HS method is compared with other normalization techniques. Its superiority, potential and robustness to high fringe density variations and the presence of noise, modulation and background illumination defects in analyzed fringe patterns has been corroborated.

Clinical application of 3D reconstruction of tracheobronchial tree with electron beam CT

International Nuclear Information System (INIS)

Yao Zhenwei; Shen Tianzhen

2002-01-01

Objective: To explore the clinical promise of CT 3D reconstruction of tracheobronchial tree (TBT) by analyzing 73 cases retrospectively. Methods: All the 73 cases were collected from October 1997 to February 2000, who were scanned by EBCT with 130 kV and 630 mA. The scanning method was continuous volume scan, the slice thickness were 3 mm or 1.5 mm. All cross-sectional images were transmitted to the INSIGHT workstation and reconstructed with SSD (shaded surface display), and the threshold setting were -500 to -300 HU. Results: 3D reconstruction of TBT with EBCT could reveal the abnormal changes of TBT by many kinds of diseases including central cancer, inflammation, bronchiectasis, saber-sheath trachea, trachea cancer, congenital disorders, post-surgical changes of lung cancer, and stenoses by adjacent benign or malignant diseases. It could be used to locate the stenoses and measure stenotic extent. Of the 35 central cancer cases with 3D reconstruction, 6 cases were pestle obstructed, 15 cases cone obstructed, 5 cases interrupted irregularly, 8 cases with eccentric stenoses, and 1 case with right stem destroyed and right upper lobe bronchus obstructed. Conclusion: 3D reconstruction of TBT has characteristic sign in the diagnosis or differential diagnosis of central airway's benign or malignant stenoses, and it is of instructional value in clinical use

Mechanisms of ear trauma and reconstructive techniques in 105 consecutive patients.

Science.gov (United States)

Kolodzynski, Michail N; Kon, Moshe; Egger, Silvan; Breugem, Corstiaan C

2017-02-01

Acquired auricular deformities may diminish facial esthetics and cause psychological distress. The aim of this article is to provide an overview of the type of injuries and applied reconstructive techniques in a large academic hospital in The Netherlands. A retrospective chart review was conducted for the last 105 patients who underwent auricular reconstruction for an acquired deformity. Data concerning gender, affected side, cause of injury, anatomical region, the previous and further surgeries, type of cartilage, and skin cover used were collected and analyzed. 105 patients were included. Acquired auricular deformities were mainly caused by bite injuries (22 %), traffic accidents (17 %), burns (9.5 %), and post-otoplasty complications (9.5 %). The upper third of the auricle was most often injured (41 %), followed by the entire auricle (19 %). 70 % of cases required reconstruction with costal cartilage. The most common form of cutaneous cover was a postauricular skin flap (40 % of cases). This study gives a complete overview of causes and treatment of acquired auricular deformities. The results are comparable with the results of similar studies found in literature. Bite wounds are the leading cause of acquired auricular injuries. The upper third is most commonly affected. In the largest percentage of reconstructions, costal cartilage and a postauricular flap were used to correct the deformity.

Prosthetic breast reconstruction: indications and update

Science.gov (United States)

Quinn, Tam T.; Miller, George S.; Rostek, Marie; Cabalag, Miguel S.; Rozen, Warren M.

2016-01-01

Background Despite 82% of patients reporting psychosocial improvement following breast reconstruction, only 33% patients choose to undergo surgery. Implant reconstruction outnumbers autologous reconstruction in many centres. Methods A systematic review of the literature was undertaken. Inclusion required: (I) Meta-analyses or review articles; (II) adult patients aged 18 years or over undergoing alloplastic breast reconstruction; (III) studies including outcome measures; (IV) case series with more than 10 patients; (V) English language; and (VI) publication after 1st January, 2000. Results After full text review, analysis and data extraction was conducted for a total of 63 articles. Definitive reconstruction with an implant can be immediate or delayed. Older patients have similar or even lower complication rates to younger patients. Complications include capsular contracture, hematoma and infection. Obesity, smoking, large breasts, diabetes and higher grade tumors are associated with increased risk of wound problems and reconstructive failure. Silicone implant patients have higher capsular contracture rates but have higher physical and psychosocial function. There were no associations made between silicone implants and cancer or systemic disease. There were no differences in outcomes or complications between round and shaped implants. Textured implants have a lower risk of capsular contracture than smooth implants. Smooth implants are more likely to be displaced as well as having higher rates of infection. Immediate breast reconstruction (IBR) gives the best aesthetic outcome if radiotherapy is not required but has a higher rate of capsular contracture and implant failure. Delayed-immediate reconstruction patients can achieve similar aesthetic results to IBR whilst preserving the breast skin if radiotherapy is required. Delayed breast reconstruction (DBR) patients have fewer complications than IBR patients. Conclusions Implant reconstruction is a safe and popular

Right adrenal vein: comparison between adaptive statistical iterative reconstruction and model-based iterative reconstruction.

Science.gov (United States)

Noda, Y; Goshima, S; Nagata, S; Miyoshi, T; Kawada, H; Kawai, N; Tanahashi, Y; Matsuo, M

2018-06-01

To compare right adrenal vein (RAV) visualisation and contrast enhancement degree on adrenal venous phase images reconstructed using adaptive statistical iterative reconstruction (ASiR) and model-based iterative reconstruction (MBIR) techniques. This prospective study was approved by the institutional review board, and written informed consent was waived. Fifty-seven consecutive patients who underwent adrenal venous phase imaging were enrolled. The same raw data were reconstructed using ASiR 40% and MBIR. The expert and beginner independently reviewed computed tomography (CT) images. RAV visualisation rates, background noise, and CT attenuation of the RAV, right adrenal gland, inferior vena cava (IVC), hepatic vein, and bilateral renal veins were compared between the two reconstruction techniques. RAV visualisation rates were higher with MBIR than with ASiR (95% versus 88%, p=0.13 in expert and 93% versus 75%, p=0.002 in beginner, respectively). RAV visualisation confidence ratings with MBIR were significantly greater than with ASiR (pASiR (pASiR (p=0.0013 and 0.02). Reconstruction of adrenal venous phase images using MBIR significantly reduces background noise, leading to an improvement in the RAV visualisation compared with ASiR. Copyright © 2018 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Maxillary reconstruction

Directory of Open Access Journals (Sweden)

Brown James

2007-12-01

Full Text Available This article aims to discuss the various defects that occur with maxillectomy with a full review of the literature and discussion of the advantages and disadvantages of the various techniques described. Reconstruction of the maxilla can be relatively simple for the standard low maxillectomy that does not involve the orbital floor (Class 2. In this situation the structure of the face is less damaged and the there are multiple reconstructive options for the restoration of the maxilla and dental alveolus. If the maxillectomy includes the orbit (Class 4 then problems involving the eye (enopthalmos, orbital dystopia, ectropion and diplopia are avoided which simplifies the reconstruction. Most controversy is associated with the maxillectomy that involves the orbital floor and dental alveolus (Class 3. A case is made for the use of the iliac crest with internal oblique as an ideal option but there are other methods, which may provide a similar result. A multidisciplinary approach to these patients is emphasised which should include a prosthodontist with a special expertise for these defects.

Renal Cyst Pseudoenhancement: Intraindividual Comparison Between Virtual Monochromatic Spectral Images and Conventional Polychromatic 120-kVp Images Obtained During the Same CT Examination and Comparisons Among Images Reconstructed Using Filtered Back Projection, Adaptive Statistical Iterative Reconstruction, and Model-Based Iterative Reconstruction

Science.gov (United States)

Yamada, Yoshitake; Yamada, Minoru; Sugisawa, Koichi; Akita, Hirotaka; Shiomi, Eisuke; Abe, Takayuki; Okuda, Shigeo; Jinzaki, Masahiro

2015-01-01

Abstract The purpose of this study was to compare renal cyst pseudoenhancement between virtual monochromatic spectral (VMS) and conventional polychromatic 120-kVp images obtained during the same abdominal computed tomography (CT) examination and among images reconstructed using filtered back projection (FBP), adaptive statistical iterative reconstruction (ASIR), and model-based iterative reconstruction (MBIR). Our institutional review board approved this prospective study; each participant provided written informed consent. Thirty-one patients (19 men, 12 women; age range, 59–85 years; mean age, 73.2 ± 5.5 years) with renal cysts underwent unenhanced 120-kVp CT followed by sequential fast kVp-switching dual-energy (80/140 kVp) and 120-kVp abdominal enhanced CT in the nephrographic phase over a 10-cm scan length with a random acquisition order and 4.5-second intervals. Fifty-one renal cysts (maximal diameter, 18.0 ± 14.7 mm [range, 4–61 mm]) were identified. The CT attenuation values of the cysts as well as of the kidneys were measured on the unenhanced images, enhanced VMS images (at 70 keV) reconstructed using FBP and ASIR from dual-energy data, and enhanced 120-kVp images reconstructed using FBP, ASIR, and MBIR. The results were analyzed using the mixed-effects model and paired t test with Bonferroni correction. The attenuation increases (pseudoenhancement) of the renal cysts on the VMS images reconstructed using FBP/ASIR (least square mean, 5.0/6.0 Hounsfield units [HU]; 95% confidence interval, 2.6–7.4/3.6–8.4 HU) were significantly lower than those on the conventional 120-kVp images reconstructed using FBP/ASIR/MBIR (least square mean, 12.1/12.8/11.8 HU; 95% confidence interval, 9.8–14.5/10.4–15.1/9.4–14.2 HU) (all P < .001); on the other hand, the CT attenuation values of the kidneys on the VMS images were comparable to those on the 120-kVp images. Regardless of the reconstruction algorithm, 70-keV VMS images showed

[Current problems in the reconstructive surgery of the locomotor apparatus in children].

Science.gov (United States)

Kupatadze, D D; Nabokov, V V; Malikov, S A; Polozov, R N; Kanina, L Ia; Veselov, A G

1997-01-01

The authors analyze results of treatment of 778 children with malignant and benign tumors of the bones, pseudoarthroses, amputations of lower extremities and fingers, injuries of the tendons, vessels and contused-lacerated wounds of distal phalanges of fingers. The possibility to use a precision technique for the reconstructive operations of the vessels in children is shown.

Reconstruction of the anterior cruciate ligament of the knee

Directory of Open Access Journals (Sweden)

Nikolić Dragan

2006-01-01

Full Text Available Background/Aim. Numerous papers on reconstruction of the anterior cruciate ligament of the knee (ACL contribute to the significance of this method. The aim of this study was to analyze the outcome of the use of this surgical treatment method regardless the type of surgical intervention, graft, and the choice of the material for fixing. Methods. The study included 324 patients treated within the period from April 1997 to April 2004. Arthroscopically assisted ACL reconstruction was typically performed using the central one-third of the patellar ligament, as a graft, with bone blocks. Fixing was performed using screws (spongy or interferential, Mitek type. In the cases who required revision of the surgery, we used a graft m. semitendinosus and m. gracilise (STG or a graft of the patellar ligament (B-Pt-B. Fixation in these cases was performed using absorptive wedges according to the Rigidfix technique or metallic implants. Results. The analysis included the results of the reconstruction of the anterior cruciate ligament of the knee (B-Pt-B or STG graft in 139 of the knees. Chronic injuries were revealed in 132 (94.9% of the knees. According to the anamnesis and clinical findings, the feeling of instability prevailed in 132 (94.9% of the knees, pain in 72 (51.7%, effluents in 24 (17.2%, and blockages in 13 (9.3%. Early and late postoperative complications were noticeable in 3.5% each. Hypotrophy of the upper knee musculature up to 2 cm was present in 53.9% of the operated knees, while minor contractions in 13.6% of them. The final result of the reconstruction graded begusing the Lysholm Scale was 85.2, simultaneous reconstructions of other ligaments 75.3, and revision surgery 68.0. First-grade degenerative postoperative changes according to the K/L Scale were found in 55.0% of the surgically treated knees, while the worst, four-grade one in 2.5%. Conclusion. On the basis of these findings, we can conclude that this method is the method of choice in

Graft infections after surgical aortic reconstructions

OpenAIRE

Berger, P.

2015-01-01

Prosthetic vascular grafts are frequently used to reconstruct (part) of the aorta. Every surgical procedure caries a certain risk for infection and when a prosthetic aortic graft is implanted, this may lead to an aortic graft infection (AGI). Endovascular techniques have gradually replaced open surgical reconstructions as first line of treatment for aorto-iliac diseases. Nowadays, open reconstructions are primarily reserved for patients unsuitable for endovascular reconstructions or for redo ...

REGEN: Ancestral Genome Reconstruction for Bacteria

OpenAIRE

Yang, Kuan; Heath, Lenwood S.; Setubal, João C.

2012-01-01

Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deleti...

Craniofacial Reconstruction Evaluation by Geodesic Network

OpenAIRE

Zhao, Junli; Liu, Cuiting; Wu, Zhongke; Duan, Fuqing; Wang, Kang; Jia, Taorui; Liu, Quansheng

2014-01-01

Craniofacial reconstruction is to estimate an individual’s face model from its skull. It has a widespread application in forensic medicine, archeology, medical cosmetic surgery, and so forth. However, little attention is paid to the evaluation of craniofacial reconstruction. This paper proposes an objective method to evaluate globally and locally the reconstructed craniofacial faces based on the geodesic network. Firstly, the geodesic networks of the reconstructed craniofacial face and the or...

Overview of image reconstruction

International Nuclear Information System (INIS)

Marr, R.B.

1980-04-01

Image reconstruction (or computerized tomography, etc.) is any process whereby a function, f, on R/sup n/ is estimated from empirical data pertaining to its integrals, ∫f(x) dx, for some collection of hyperplanes of dimension k < n. The paper begins with background information on how image reconstruction problems have arisen in practice, and describes some of the application areas of past or current interest; these include radioastronomy, optics, radiology and nuclear medicine, electron microscopy, acoustical imaging, geophysical tomography, nondestructive testing, and NMR zeugmatography. Then the various reconstruction algorithms are discussed in five classes: summation, or simple back-projection; convolution, or filtered back-projection; Fourier and other functional transforms; orthogonal function series expansion; and iterative methods. Certain more technical mathematical aspects of image reconstruction are considered from the standpoint of uniqueness, consistency, and stability of solution. The paper concludes by presenting certain open problems. 73 references

Virtual 3-D Facial Reconstruction

Directory of Open Access Journals (Sweden)

Martin Paul Evison

2000-06-01

Full Text Available Facial reconstructions in archaeology allow empathy with people who lived in the past and enjoy considerable popularity with the public. It is a common misconception that facial reconstruction will produce an exact likeness; a resemblance is the best that can be hoped for. Research at Sheffield University is aimed at the development of a computer system for facial reconstruction that will be accurate, rapid, repeatable, accessible and flexible. This research is described and prototypical 3-D facial reconstructions are presented. Interpolation models simulating obesity, ageing and ethnic affiliation are also described. Some strengths and weaknesses in the models, and their potential for application in archaeology are discussed.

Maximum a posteriori reconstruction of the Patlak parametric image from sinograms in dynamic PET

International Nuclear Information System (INIS)

Wang Guobao; Fu Lin; Qi Jinyi

2008-01-01

Parametric imaging using the Patlak graphical method has been widely used to analyze dynamic PET data. Conventionally a Patlak parametric image is generated by reconstructing a sequence of dynamic images first and then performing Patlak graphical analysis on the time-activity curves pixel-by-pixel. However, because it is rather difficult to model the noise distribution in reconstructed images, the spatially variant noise correlation is simply ignored in the Patlak analysis, which leads to sub-optimal results. In this paper we present a Bayesian method for reconstructing Patlak parametric images directly from raw sinogram data by incorporating the Patlak plot model into the image reconstruction procedure. A preconditioned conjugate gradient algorithm is used to find the maximum a posteriori solution. The proposed direct method is statistically more efficient than the conventional indirect approach because the Poisson noise distribution in PET data can be accurately modeled in the direct reconstruction. The computation cost of the direct method is similar to reconstruction time of two dynamic frames. Therefore, when more than two dynamic frames are used in the Patlak analysis, the direct method is faster than the conventional indirect approach. We conduct computer simulations to validate the proposed direct method. Comparisons with the conventional indirect approach show that the proposed method results in a more accurate estimate of the parametric image. The proposed method has been applied to dynamic fully 3D PET data from a microPET scanner

Accurate reconstruction in digital holographic microscopy using Fresnel dual-tree complex wavelet transform

Science.gov (United States)

Zhang, Xiaolei; Zhang, Xiangchao; Yuan, He; Zhang, Hao; Xu, Min

2018-02-01

Digital holography is a promising measurement method in the fields of bio-medicine and micro-electronics. But the captured images of digital holography are severely polluted by the speckle noise because of optical scattering and diffraction. Via analyzing the properties of Fresnel diffraction and the topographies of micro-structures, a novel reconstruction method based on the dual-tree complex wavelet transform (DT-CWT) is proposed. This algorithm is shiftinvariant and capable of obtaining sparse representations for the diffracted signals of salient features, thus it is well suited for multiresolution processing of the interferometric holograms of directional morphologies. An explicit representation of orthogonal Fresnel DT-CWT bases and a specific filtering method are developed. This method can effectively remove the speckle noise without destroying the salient features. Finally, the proposed reconstruction method is compared with the conventional Fresnel diffraction integration and Fresnel wavelet transform with compressive sensing methods to validate its remarkable superiority on the aspects of topography reconstruction and speckle removal.

Image quality of iterative reconstruction in cranial CT imaging: comparison of model-based iterative reconstruction (MBIR) and adaptive statistical iterative reconstruction (ASiR).

Science.gov (United States)

Notohamiprodjo, S; Deak, Z; Meurer, F; Maertz, F; Mueck, F G; Geyer, L L; Wirth, S

2015-01-01

The purpose of this study was to compare cranial CT (CCT) image quality (IQ) of the MBIR algorithm with standard iterative reconstruction (ASiR). In this institutional review board (IRB)-approved study, raw data sets of 100 unenhanced CCT examinations (120 kV, 50-260 mAs, 20 mm collimation, 0.984 pitch) were reconstructed with both ASiR and MBIR. Signal-to-noise (SNR) and contrast-to-noise (CNR) were calculated from attenuation values measured in caudate nucleus, frontal white matter, anterior ventricle horn, fourth ventricle, and pons. Two radiologists, who were blinded to the reconstruction algorithms, evaluated anonymized multiplanar reformations of 2.5 mm with respect to depiction of different parenchymal structures and impact of artefacts on IQ with a five-point scale (0: unacceptable, 1: less than average, 2: average, 3: above average, 4: excellent). MBIR decreased artefacts more effectively than ASiR (p ASiR was 2 (p ASiR (p ASiR. As CCT is an examination that is frequently required, the use of MBIR may allow for substantial reduction of radiation exposure caused by medical diagnostics. • Model-Based iterative reconstruction (MBIR) effectively decreased artefacts in cranial CT. • MBIR reconstructed images were rated with significantly higher scores for image quality. • Model-Based iterative reconstruction may allow reduced-dose diagnostic examination protocols.

REGEN: Ancestral Genome Reconstruction for Bacteria.

Science.gov (United States)

Yang, Kuan; Heath, Lenwood S; Setubal, João C

2012-07-18

Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deletion and replicon fission and fusion. The reconstruction can be performed by either a maximum parsimony or a maximum likelihood method. Gene content reconstruction is based on the concept of neighboring gene pairs. REGEN was designed to be used with any set of genomes that are sufficiently related, which will usually be the case for bacteria within the same taxonomic order. We evaluated REGEN using simulated genomes and genomes in the Rhizobiales order.

Improvement of Students’ Ability to Analyzing Cases on Case Studies Through Journal and Learning Log

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Riska Ahmad

2017-08-01

Full Text Available The purpose of this research is to improve the ability of students in guidance and counseling  to  analyzing the case through journals and learning logs This research is classroom action research consists of two cycles. The research phase consisted of planning, implementation, observation and reflection. The research subject are students in guidance and counseling while they are in sixth semester, totaling 20 people who were taking courses in Case Study. The research instrument is the observation guidelines, assessment rubrics and documentation of case studies in the form of journals and learning logs, and case study reports. The study was conducted collaboratively with student magister’s program guidance and counseling. The results showed that in cycle 1 students are able to identify cases, to develop ideas about the case, select and use instruments to analyze the cause of the problem. The results of the research cycle 2, showed 17 of the 20 students were able to analyze the cause of the problem, select the type of service and provide appropriate assistance in accordance with problem cases. Overall value obtained by the students in the subject of Case Studies also increased. In terms of the ability of explanation of the concept, the concept of truth and creativity, based on the ratings given by fellow students of average ability students were in either category, although there is less good, as are associated with the activity of the opinion and the quality of the opinions expressed.

The RAVE/VERTIGO vertex reconstruction toolkit and framework

Science.gov (United States)

Waltenberger, W.; Mitaroff, W.; Moser, F.; Pflugfelder, B.; Riedel, H. V.

2008-07-01

A detector-independent toolkit for vertex reconstruction (RAVE1) is being developed, along with a standalone framework (VERTIGO2) for testing, analyzing and debugging. The core algorithms represent state-of-the-art for geometric vertex finding and fitting by both linear (Kalman filter) and robust estimation methods. Main design goals are ease of use, flexibility for embedding into existing software frameworks, extensibility, and openness. The implementation is based on modern object-oriented techniques, is coded in C++ with interfaces for Java and Python, and follows an open-source approach. A beta release is available.

CT interpretation of craniofacial anomalies: a comparative analysis by undergraduate dental students

International Nuclear Information System (INIS)

Gaia, Bruno Felipe; Perella, Andreia; Cara, Ana Claudia Ballet de; Antunes, Jose Leopoldo Ferreira; Cavalcanti, Marcelo Gusmao Paraiso

2005-01-01

The aim of this study was to evaluate the accuracy and reproducibility of computed tomography (CT) image interpretation made in axial slices (2D-CT) and 3D reconstructed images (3D-CT) of patients with craniofacial anomalies. The analyses were made by undergraduate dental students, and compared with the diagnoses considered upon surgical intervention. Computed tomography of 43 patients were analyzed independently by three calibrated examiners (undergraduate students) with, respectively, one, two, and three semesters of experience in craniofacial CT training and interpretation. The analysis of 2D-CT and 3D-CT images were performed at distinct times using an independent workstation associated with a specific computer graphics software for volumetric images. The analysis of inter-examiner agreement and of the agreement between observers and the gold standard was performed using the Kappa test. The accuracy evaluation presented a progressively higher value for examiners with progressively broader experience in 2D-CT and 3D-CT image interpretation. 3D-CT analyses allowed a higher inter-examiner agreement (1 - 0.896) than 2D-CT analyses (1 - 0.614). 3D-CT was considered more precise and accurate than 2D-CT for all students' evaluations. The reproducibility and accuracy varied according to the experience in CT interpretation, and the most experienced student achieved results closer to the gold standard. (author)

Analyzing Student Perceptions on Translanguaging: A Case Study of a Puerto Rican University Classroom

Directory of Open Access Journals (Sweden)

Adrian J. Rivera

2017-02-01

Full Text Available Translanguaging in the classroom is gaining traction as a viable pedagogical choice. Often overlooked, though, are the students’ attitudes in response to strategic classroom translanguaging. This study seeks to determine whether students’ language attitudes influence their perceptions of an instructor’s translingual pedagogy. The study took place in an undergraduate psychology classroom at the University of Puerto Rico, Mayagüez, and involved a case-study approach and analysis of survey results. The results show this particular group of students has a neutral to positive outlook on classroom translanguaging. The high number of neutral responses may mean students are indifferent to translingual pedagogy or that these students are conditioned to work within a context where code switching and translanguaging happen frequently.

Delayed reconstruction of mangled lower extremities: soft tissue management

OpenAIRE

Tiftikçioğlu, Yiğit Özer; Erçin, Burak Sercan; Erdem, Mehmet; Biçer, Ahmet; Özkayın, Nadir; Özek, Cüneyt

2018-01-01

Objectives: This study aims to propose a new, practical and versatile algorithm for the management of traumatic lower limb soft tissue wounds for patients who did not undergo early reconstruction.Materials and methods: A total of 81 patients (54 males, 27 females; mean age 37.1 years; range 11 to 64 years) managed due to complex lower limb injuries at our institution between January 2008 and December 2012 were analyzed retrospectively in this study. Age and gender of the patients, type of tra...

Impact of Postoperative Antibiotic Prophylaxis Duration on Surgical Site Infections in Autologous Breast Reconstruction.

Science.gov (United States)

Drury, Kerry E; Lanier, Steven T; Khavanin, Nima; Hume, Keith M; Gutowski, Karol A; Thornton, Brian P; Hansen, Nora M; Murphy, Robert X; Fine, Neil A; Kim, John Y S

2016-02-01

Although some surgeons prescribe prolonged postoperative antibiotics after autologous breast reconstruction, evidence is lacking to support this practice. We used the Tracking Operations and Outcomes for Plastic Surgeons database to evaluate the association between postoperative antibiotic duration and the rate of surgical site infection (SSI) in autologous breast reconstruction. The intervention of interest for this study was postoperative duration of antibiotic prophylaxis: either discontinued 24 hours after surgery or continued beyond 24 hours. The primary outcome variable of interest for this study was the presence of SSI within 30 days of autologous breast reconstruction. Cohort characteristics and 30-day outcomes were compared using χ² and Fischer exact tests for categorical variables and Student t tests for continuous variables. Multivariate logistic regression was used to control for confounders. A total of 1036 patients met inclusion criteria for our study. Six hundred fifty-nine patients (63.6%) received antibiotics for 24 hours postoperatively, and 377 patients (36.4%) received antibiotics for greater than 24 hours. The rate of SSI did not differ significantly between patients given antibiotics for only 24 hours and those continued on antibiotics beyond the 24-hour postoperative time period (5.01% vs 2.92%, P = 0.109). Furthermore, antibiotic duration was not predictive of SSI in multivariate regression modeling. We did not find a statistically significant difference in the rate of SSI in patients who received 24 hours of postoperative antibiotics compared to those that received antibiotics for greater than 24 hours. These findings held for both purely autologous reconstruction as well as latissimus dorsi reconstruction in conjunction with an implant. Thus, our study does not support continuation of postoperative antibiotics beyond 24 hours after autologous breast reconstruction.

Bayesian 3D X-ray computed tomography image reconstruction with a scaled Gaussian mixture prior model

International Nuclear Information System (INIS)

Wang, Li; Gac, Nicolas; Mohammad-Djafari, Ali

2015-01-01

In order to improve quality of 3D X-ray tomography reconstruction for Non Destructive Testing (NDT), we investigate in this paper hierarchical Bayesian methods. In NDT, useful prior information on the volume like the limited number of materials or the presence of homogeneous area can be included in the iterative reconstruction algorithms. In hierarchical Bayesian methods, not only the volume is estimated thanks to the prior model of the volume but also the hyper parameters of this prior. This additional complexity in the reconstruction methods when applied to large volumes (from 512 3 to 8192 3 voxels) results in an increasing computational cost. To reduce it, the hierarchical Bayesian methods investigated in this paper lead to an algorithm acceleration by Variational Bayesian Approximation (VBA) [1] and hardware acceleration thanks to projection and back-projection operators paralleled on many core processors like GPU [2]. In this paper, we will consider a Student-t prior on the gradient of the image implemented in a hierarchical way [3, 4, 1]. Operators H (forward or projection) and H t (adjoint or back-projection) implanted in multi-GPU [2] have been used in this study. Different methods will be evalued on synthetic volume 'Shepp and Logan' in terms of quality and time of reconstruction. We used several simple regularizations of order 1 and order 2. Other prior models also exists [5]. Sometimes for a discrete image, we can do the segmentation and reconstruction at the same time, then the reconstruction can be done with less projections

3D Printing Technology in Planning Thumb Reconstructions with Second Toe Transplant.

Science.gov (United States)

Zang, Cheng-Wu; Zhang, Jian-Lei; Meng, Ze-Zu; Liu, Lin-Feng; Zhang, Wen-Zhi; Chen, Yong-Xiang; Cong, Rui

2017-05-01

To report preoperative planning using 3D printing to plan thumb reconstructions with second toe transplant. Between December 2013 and October 2015, the thumbs of five patients with grade 3 thumb defects were reconstructed using a wrap-around flap and second toe transplant aided by 3D printing technology. CT scans of hands and feet were analyzed using Boholo surgical simulator software (www.boholo.com). This allowed for the creation of a mirror image of the healthy thumb using the uninjured thumb. Using 3D images of the reconstructed thumb, a model of the big toe and the second toe was created to understand the dimensions of the donor site. This model was also used to repair the donor site defect by designing appropriate iliac bone and superficial circumflex iliac artery flaps. The polylactic acid model of the donor toes and reconstructed thumb was produced using 3D printing. Surgically, the wrap-around flap of the first dorsal metatarsal artery and vein combined with the joint and bone of the second toe was based upon the model donor site. Sensation was reconstructed by anastomosing the dorsal nerve of the foot and the plantar digital nerve of the great toe. Patients commenced exercises 2 weeks after surgery. All reconstructed thumbs survived, although partial flap necrosis occurred in one case. This was managed with regular dressing changes. Patients were followed up for 3-15 months. The lengths of the reconstructed thumbs are 34-49 mm. The widths of the thumb nail beds are 16-19 mm, and the thickness of the digital pulp is 16-20 mm. The thumb opposition function was 0-1.5 cm; the extension angle was 5°-20° (mean, 16°), and the angle of flexion was 38°-55° (mean, 47°). Two-point discrimination was 9-11 mm (mean, 9.6 mm). The reconstructed thumbs had good appearance, function and sensation. Based on the criteria set forth by the Standard on Approval of Reconstructed Thumb and Finger Functional Assessment of the Chinese Medical Association, the results were

REGEN: Ancestral Genome Reconstruction for Bacteria

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João C. Setubal

2012-07-01

Full Text Available Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deletion and replicon fission and fusion. The reconstruction can be performed by either a maximum parsimony or a maximum likelihood method. Gene content reconstruction is based on the concept of neighboring gene pairs. REGEN was designed to be used with any set of genomes that are sufficiently related, which will usually be the case for bacteria within the same taxonomic order. We evaluated REGEN using simulated genomes and genomes in the Rhizobiales order.

Computer Based Road Accident Reconstruction Experiences

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Milan Batista

2005-03-01

Full Text Available Since road accident analyses and reconstructions are increasinglybased on specific computer software for simulationof vehicle d1iving dynamics and collision dynamics, and forsimulation of a set of trial runs from which the model that bestdescribes a real event can be selected, the paper presents anoverview of some computer software and methods available toaccident reconstruction experts. Besides being time-saving,when properly used such computer software can provide moreauthentic and more trustworthy accident reconstruction, thereforepractical experiences while using computer software toolsfor road accident reconstruction obtained in the TransportSafety Laboratory at the Faculty for Maritime Studies andTransport of the University of Ljubljana are presented and discussed.This paper addresses also software technology for extractingmaximum information from the accident photo-documentationto support accident reconstruction based on the simulationsoftware, as well as the field work of reconstruction expertsor police on the road accident scene defined by this technology.

Defining and reconstructing clinical processes based on IHE and BPMN 2.0.

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Strasser, Melanie; Pfeifer, Franz; Helm, Emmanuel; Schuler, Andreas; Altmann, Josef

2011-01-01

This paper describes the current status and the results of our process management system for defining and reconstructing clinical care processes, which contributes to compare, analyze and evaluate clinical processes and further to identify high cost tasks or stays. The system is founded on IHE, which guarantees standardized interfaces and interoperability between clinical information systems. At the heart of the system there is BPMN, a modeling notation and specification language, which allows the definition and execution of clinical processes. The system provides functionality to define healthcare information system independent clinical core processes and to execute the processes in a workflow engine. Furthermore, the reconstruction of clinical processes is done by evaluating an IHE audit log database, which records patient movements within a health care facility. The main goal of the system is to assist hospital operators and clinical process managers to detect discrepancies between defined and actual clinical processes and as well to identify main causes of high medical costs. Beyond that, the system can potentially contribute to reconstruct and improve clinical processes and enhance cost control and patient care quality.

Analyzing Interpersonal Problem Solving in Terms of Solution Focused Approach and Humor Styles of University Student

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Koc, Hayri; Arslan, Coskun

2017-01-01

In this study university students interpersonal problem solving approaches were investigated in terms of solution focused approach and humor styles. The participants were 773 (542 female and 231 male, between 17-33 years old) university students. To determine the university students' problem solving approaches "Interpersonal Problem Solving…

Software for 3D diagnostic image reconstruction and analysis

International Nuclear Information System (INIS)

Taton, G.; Rokita, E.; Sierzega, M.; Klek, S.; Kulig, J.; Urbanik, A.

2005-01-01

Recent advances in computer technologies have opened new frontiers in medical diagnostics. Interesting possibilities are the use of three-dimensional (3D) imaging and the combination of images from different modalities. Software prepared in our laboratories devoted to 3D image reconstruction and analysis from computed tomography and ultrasonography is presented. In developing our software it was assumed that it should be applicable in standard medical practice, i.e. it should work effectively with a PC. An additional feature is the possibility of combining 3D images from different modalities. The reconstruction and data processing can be conducted using a standard PC, so low investment costs result in the introduction of advanced and useful diagnostic possibilities. The program was tested on a PC using DICOM data from computed tomography and TIFF files obtained from a 3D ultrasound system. The results of the anthropomorphic phantom and patient data were taken into consideration. A new approach was used to achieve spatial correlation of two independently obtained 3D images. The method relies on the use of four pairs of markers within the regions under consideration. The user selects the markers manually and the computer calculates the transformations necessary for coupling the images. The main software feature is the possibility of 3D image reconstruction from a series of two-dimensional (2D) images. The reconstructed 3D image can be: (1) viewed with the most popular methods of 3D image viewing, (2) filtered and processed to improve image quality, (3) analyzed quantitatively (geometrical measurements), and (4) coupled with another, independently acquired 3D image. The reconstructed and processed 3D image can be stored at every stage of image processing. The overall software performance was good considering the relatively low costs of the hardware used and the huge data sets processed. The program can be freely used and tested (source code and program available at

Data-parallel tomographic reconstruction : A comparison of filtered backprojection and direct Fourier reconstruction

NARCIS (Netherlands)

Roerdink, J.B.T.M.; Westenberg, M.A

1998-01-01

We consider the parallelization of two standard 2D reconstruction algorithms, filtered backprojection and direct Fourier reconstruction, using the data-parallel programming style. The algorithms are implemented on a Connection Machine CM-5 with 16 processors and a peak performance of 2 Gflop/s.

The Type of Breast Reconstruction May Not Influence Patient Satisfaction in the Chinese Population: A Single Institutional Experience

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Chen, Jiaying; Chen, Ying; Hu, Zhen; Liu, Guangyu; Shen, Zhenzhou; Shao, Zhimin; Wu, Jiong

2015-01-01

Background The goal of this study was to evaluate patient satisfaction with four common types of breast reconstruction performed at our institution: latissimus dorsi myocutaneous (LDM) flap reconstruction with or without implants, pedicled transverse rectus abdominis musculocutaneous (TRAM) flap reconstruction, and free deep inferior epigastric perforator (DIEP) flap reconstruction. Methods A custom survey consisting of questions that assessed general and aesthetic satisfaction was sent to patients who had undergone breast reconstruction in the last 5 years. The clinical data and details of the surgery were also collected from the patients who returned the surveys. We compared satisfaction rates across the four breast reconstruction types and analyzed the effects of various factors on overall general and aesthetic satisfaction rates using a binary logistic regression model. Result A total of 207 (72%) patients completed the questionnaires. Overall, significant differences in general and aesthetic satisfaction among the four procedures were not observed. A multivariate analysis revealed that the factor “complications” (p = 0.001) played a significant role in general satisfaction and that the factors “> 2 years since reconstruction” (p = 0.043) and “age > 35 years” (p = 0.05) played significant roles in overall aesthetic satisfaction. Conclusion The present study demonstrated that the type of breast reconstruction might not influence satisfaction in Chinese patients. PMID:26562294

Accident reconstruction to analyze impact of injured drivers during the collision. Ankle fracture in the car-to-car offset frontal collision; Join no jusho jokyo ni kansuru jiko saigen. Joyosha doshi no offset zenmen shototsuji no ashi kansetsu kossetsu

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Sakurai, M [Japan Automobile Research Institute Inc., Tsukuba (Japan)

1997-10-01

An accident reconstruction test of car-to-car crash was conducted in order to analyze the impact on the driver in the offset head-on collision. The ankle fracture of the driver resulting from the accident was examined with the test results and the accident data. The test results of the car-to-car crashes indicated that the belted driver`s ankle would have fractured in the early stage of the crash. The detailed information from the accident data, especially the cars` interior deformation and the driver`s X-ray photographs, was also very important in analyzing injury mechanisms of the ankle/foot region. The above results suggested an injury mechanism that the ankle joint fracture was due to dorsiflexion and valgus resulting from the impact and intrusion of the toeboard in the early stage of the crash. 12 refs., 11 figs.

A Graph-Based Approach for 3D Building Model Reconstruction from Airborne LiDAR Point Clouds

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Bin Wu

2017-01-01

Full Text Available 3D building model reconstruction is of great importance for environmental and urban applications. Airborne light detection and ranging (LiDAR is a very useful data source for acquiring detailed geometric and topological information of building objects. In this study, we employed a graph-based method based on hierarchical structure analysis of building contours derived from LiDAR data to reconstruct urban building models. The proposed approach first uses a graph theory-based localized contour tree method to represent the topological structure of buildings, then separates the buildings into different parts by analyzing their topological relationships, and finally reconstructs the building model by integrating all the individual models established through the bipartite graph matching process. Our approach provides a more complete topological and geometrical description of building contours than existing approaches. We evaluated the proposed method by applying it to the Lujiazui region in Shanghai, China, a complex and large urban scene with various types of buildings. The results revealed that complex buildings could be reconstructed successfully with a mean modeling error of 0.32 m. Our proposed method offers a promising solution for 3D building model reconstruction from airborne LiDAR point clouds.

Vertex Reconstruction in ATLAS Run II

CERN Document Server

Zhang, Matt; The ATLAS collaboration

2016-01-01

Vertex reconstruction is the process of taking reconstructed tracks and using them to determine the locations of proton collisions. In this poster we present the performance of our current vertex reconstruction algorithm, and look at investigations into potential improvements from a new seed finding method.

Analyzing Student Teachers' Academic Literacy Needs: A Qualitative Analysis of Flemish First-Year Teacher Trainees' Needs

Science.gov (United States)

Van Houtven, Tine; Peters, Elke; Van den Branden, Kris

2013-01-01

In recent years, the student population enrolling in Flemish higher education has become increasingly diverse. Whereas teacher training institutes used to attract mainly students with a diploma of general secondary education, the proportion of students with a technical or vocational educational background has grown substantially over the past ten…

Fat injection to correct contour deformities of the reconstructed breast: a single surgeon experience

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Youssef Tahiri

2015-06-01

Full Text Available Aim: Autologous fat grafting has gained acceptance as a technique to improve aesthetic outcomes in breast reconstruction. The purpose of this study was to share our clinical experience using autologous fat injection to correct contour deformities during breast reconstruction. Methods: A single surgeon, prospectively maintained database of patients who underwent autologous fat injection during breast reconstruction from January 2008 to November 2013 at McGill University Health Center was reviewed. Patient characteristics, breast history, type of breast reconstruction, volume of fat injected, and complications were analyzed. Results: One hundred and twenty-four patients benefited from autologous fat injection from January 2008 to November 2013, for a total of 187 treated breasts. The patients were on average 49.3 years old (΁ 8.9 years. Fat was harvested from the medial thighs (20.5%, flanks (39.1%, medial thighs and flanks (2.9%, trochanters (13.3%, medial knees (2.7%, and abdomen (21.9%. An average of 49.25 mL of fat was injected into each reconstructed breast. A total of 187 breasts in 124 patients were lipo-infiltrated during the second stage of breast reconstruction. Thirteen breasts (in 12 separate patients were injected several years after having undergone lumpectomy and radiotherapy. Of the 187 treated breasts, 118 were reconstructed with expanders to implants, 45 with deep inferior epigastric perforator flaps, 9 with latissimus dorsi flaps with implants, 4 with transverse rectus abdominis myocutaneous flaps, and 13 had previously undergone lumpectomy and radiotherapy. Six complications were noted in the entire series, for a rate of 3.2%. All were in previously radiated breasts. Average follow-up time was 12 months (range: 2-36 months. Conclusion: Fat injection continues to grow in popularity as an adjunct to breast reconstruction. Our experience demonstrates a low complication rate as compared to most surgical interventions of the breast

Photoacoustic image reconstruction via deep learning

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Antholzer, Stephan; Haltmeier, Markus; Nuster, Robert; Schwab, Johannes

2018-02-01

Applying standard algorithms to sparse data problems in photoacoustic tomography (PAT) yields low-quality images containing severe under-sampling artifacts. To some extent, these artifacts can be reduced by iterative image reconstruction algorithms which allow to include prior knowledge such as smoothness, total variation (TV) or sparsity constraints. These algorithms tend to be time consuming as the forward and adjoint problems have to be solved repeatedly. Further, iterative algorithms have additional drawbacks. For example, the reconstruction quality strongly depends on a-priori model assumptions about the objects to be recovered, which are often not strictly satisfied in practical applications. To overcome these issues, in this paper, we develop direct and efficient reconstruction algorithms based on deep learning. As opposed to iterative algorithms, we apply a convolutional neural network, whose parameters are trained before the reconstruction process based on a set of training data. For actual image reconstruction, a single evaluation of the trained network yields the desired result. Our presented numerical results (using two different network architectures) demonstrate that the proposed deep learning approach reconstructs images with a quality comparable to state of the art iterative reconstruction methods.

Skin-Reducing Mastectomy in Immediate Reconstruction: How to Limit Complications and Failures.

Science.gov (United States)

Pechevy, Lolita; Carloni, Raphael; Guerid, Samia; Vincent, Pierre-Luc; Toussoun, Gilles; Delay, Emmanuel

2017-06-01

In hypertrophic and/or very ptotic breasts, skin-reducing mastectomy (SRM) is challenging and the risk of complications is high. Few publications have reported the use of an autologous latissimus dorsi flap (ALDF) in this indication. Most studies opt for implant reconstructions, with a high failure rate. We aimed to identify and present the technical refinements that reduce the risk of reconstruction failure in patients with hypertrophic and/or ptotic breasts with breast cancer or at risk of breast cancer after SRM with immediate breast reconstruction (IBR) utilizing an ALDF. Our retrospective study, covering a period of 18 years, included a series of 60 patients with hypertrophic and/or ptotic breasts who underwent 67 SRM and IBR procedures utilizing an ALDF. The complications were recorded and the risk factors analyzed. Sixty-seven SRMs were reviewed. Forty-nine procedures were performed with an inverted-T scar technique and 18 with a vertical scar technique. The nipple-areola complex (NAC) was preserved in 10 cases. There were eight (11.9%) cases of minor mastectomy flap necrosis after skin-reducing reconstructions, 16 (23.8%) wound dehiscences, no infections, no breast seromas, and no reconstruction failures. Smoking increased the risk of minor mastectomy flap necrosis (P = 0.048) and wound dehiscence (P = 0.002). Previous radiotherapy was associated with minor mastectomy flap necrosis (P = 0.001). The use of an ALDF together with technical refinements that preserve the vascular supply of the skin envelope leads to successful IBR with consistently good aesthetic results. Above all, it avoids failure of the reconstruction in very large or ptotic breasts. © 2017 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com

Patient Information Needs and Breast Reconstruction After Mastectomy: A Qualitative Meta-Synthesis.

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Carr, Tracey L; Groot, Gary; Cochran, David; Holtslander, Lorraine

2018-04-27

Although many women benefit from breast reconstruction after mastectomy, several studies report women's dissatisfaction with the level of information they were provided with before reconstruction. The present meta-synthesis examines the qualitative literature that explores women's experiences of breast reconstruction after mastectomy and highlights women's healthcare information needs. After a comprehensive search of 6 electronic databases (CINAHL, Cochrane Library, EMBASE, MEDLINE, PsycINFO, and Scopus), we followed the methodology for synthesizing qualitative research. The search produced 423 studies, which were assessed against 5 inclusion criteria. A meta-synthesis methodology was used to analyze the data through taxonomic classification and constant targeted comparison. Some 17 studies met the inclusion criteria, and findings from 16 studies were synthesized. The role of the healthcare practitioner is noted as a major influence on women's expectations, and in some instances, women did not feel adequately informed about the outcomes of surgery and the recovery process. In general, women's desire for normality and effective emotional coping shapes their information needs. The information needs of women are better understood after considering women's actual experiences with breast reconstruction. It is important to inform women of the immediate outcomes of reconstruction surgery and the recovery process. In an attempt to better address women's information needs, healthcare practitioners should discover women's initial expectations of reconstruction as a starting point in the consultation. In addition, the research revealed the importance of the nurse navigator in terms of assisting women through the recovery process.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work

Comparison of Outcomes in Immediate Implant-Based Breast Reconstruction Versus Mastectomy Alone.

Science.gov (United States)

Sousa, Janelle; Sood, Ravi; Liu, Daniel; Calhoun, Kristine; Louie, Otway; Neligan, Peter; Said, Hakim; Mathes, David

2018-02-01

Immediate implant-based techniques are common practice in post-mastectomy breast reconstruction. Previous studies have shown an increased complication rate in the setting of immediate versus delayed, MD reconstruction. We aimed to quantify any additional risk in complications when implant-based immediate breast reconstruction (IBR) is performed versus mastectomy alone. We retrospectively reviewed all IBR cases and all mastectomies without reconstruction from 2007 to 2011. Patient characteristics, operative details, and complication rates were reviewed and analyzed. IBR was performed in 315 consecutive women; mastectomy alone was performed in 401 women. Patients undergoing mastectomy alone were more often older, diabetic, and more frequently underwent neoadjuvant chemotherapy or radiation. Overall complications were higher in the IBR group, most commonly reoperation and delayed wound healing. In a multivariate analysis, IBR, increasing age, body mass index, history of radiation therapy, smoking, and nipple-sparing mastectomy were independently associated with increased risk of complications. However, IBR was only independently associated with increased risk of major complications such as reoperation or readmission for intravenous antibiotics, not minor complications. Patients selected for IBR are inherently different than those undergoing mastectomy alone. After adjusting for these differences, the increased risk of complications seen in IBR is moderately increased over the risk of complications in mastectomy alone. The observed increased risk of major complications after IBR is largely due to the aggressive management of complications in the setting of a prosthetic implant. IBR is a safe reconstructive strategy with only a slightly increased risk over mastectomy alone.

Resistance to compression of weakened roots subjected to different root reconstruction protocols

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Lucas Villaça Zogheib

2011-12-01

Full Text Available OBJECTIVE: This study evaluated, in vitro, the fracture resistance of human non-vital teeth restored with different reconstruction protocols. MATERIAL AND METHODS: Forty human anterior roots of similar shape and dimensions were assigned to four groups (n=10, according to the root reconstruction protocol: Group I (control: non-weakened roots with glass fiber post; Group II: roots with composite resin by incremental technique and glass fiber post; Group III: roots with accessory glass fiber posts and glass fiber post; and Group IV: roots with anatomic glass fiber post technique. Following post cementation and core reconstruction, the roots were embedded in chemically activated acrylic resin and submitted to fracture resistance testing, with a compressive load at an angle of 45º in relation to the long axis of the root at a speed of 0.5 mm/min until fracture. All data were statistically analyzed with bilateral Dunnett's test (α=0.05. RESULTS: Group I presented higher mean values of fracture resistance when compared with the three experimental groups, which, in turn, presented similar resistance to fracture among each other. None of the techniques of root reconstruction with intraradicular posts improved root strength, and the incremental technique was suggested as being the most recommendable, since the type of fracture that occurred allowed the remaining dental structure to be repaired. CONCLUSION: The results of this in vitro study suggest that the healthy remaining radicular dentin is more important to increase fracture resistance than the root reconstruction protocol.

Forensic Facial Reconstruction: The Final Frontier.

Science.gov (United States)

Gupta, Sonia; Gupta, Vineeta; Vij, Hitesh; Vij, Ruchieka; Tyagi, Nutan

2015-09-01

Forensic facial reconstruction can be used to identify unknown human remains when other techniques fail. Through this article, we attempt to review the different methods of facial reconstruction reported in literature. There are several techniques of doing facial reconstruction, which vary from two dimensional drawings to three dimensional clay models. With the advancement in 3D technology, a rapid, efficient and cost effective computerized 3D forensic facial reconstruction method has been developed which has brought down the degree of error previously encountered. There are several methods of manual facial reconstruction but the combination Manchester method has been reported to be the best and most accurate method for the positive recognition of an individual. Recognition allows the involved government agencies to make a list of suspected victims'. This list can then be narrowed down and a positive identification may be given by the more conventional method of forensic medicine. Facial reconstruction allows visual identification by the individual's family and associates to become easy and more definite.

Effects of illumination differences on photometric stereo shape-and-albedo-from-shading for precision lunar surface reconstruction

Science.gov (United States)

Chung Liu, Wai; Wu, Bo; Wöhler, Christian

2018-02-01

Photoclinometric surface reconstruction techniques such as Shape-from-Shading (SfS) and Shape-and-Albedo-from-Shading (SAfS) retrieve topographic information of a surface on the basis of the reflectance information embedded in the image intensity of each pixel. SfS or SAfS techniques have been utilized to generate pixel-resolution digital elevation models (DEMs) of the Moon and other planetary bodies. Photometric stereo SAfS analyzes images under multiple illumination conditions to improve the robustness of reconstruction. In this case, the directional difference in illumination between the images is likely to affect the quality of the reconstruction result. In this study, we quantitatively investigate the effects of illumination differences on photometric stereo SAfS. Firstly, an algorithm for photometric stereo SAfS is developed, and then, an error model is derived to analyze the relationships between the azimuthal and zenith angles of illumination of the images and the reconstruction qualities. The developed algorithm and error model were verified with high-resolution images collected by the Narrow Angle Camera (NAC) of the Lunar Reconnaissance Orbiter Camera (LROC). Experimental analyses reveal that (1) the resulting error in photometric stereo SAfS depends on both the azimuthal and the zenith angles of illumination as well as the general intensity of the images and (2) the predictions from the proposed error model are consistent with the actual slope errors obtained by photometric stereo SAfS using the LROC NAC images. The proposed error model enriches the theory of photometric stereo SAfS and is of significance for optimized lunar surface reconstruction based on SAfS techniques.

The SRT reconstruction algorithm for semiquantification in PET imaging

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Kastis, George A., E-mail: gkastis@academyofathens.gr [Research Center of Mathematics, Academy of Athens, Athens 11527 (Greece); Gaitanis, Anastasios [Biomedical Research Foundation of the Academy of Athens (BRFAA), Athens 11527 (Greece); Samartzis, Alexandros P. [Nuclear Medicine Department, Evangelismos General Hospital, Athens 10676 (Greece); Fokas, Athanasios S. [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB30WA, United Kingdom and Research Center of Mathematics, Academy of Athens, Athens 11527 (Greece)

2015-10-15

Purpose: The spline reconstruction technique (SRT) is a new, fast algorithm based on a novel numerical implementation of an analytic representation of the inverse Radon transform. The mathematical details of this algorithm and comparisons with filtered backprojection were presented earlier in the literature. In this study, the authors present a comparison between SRT and the ordered-subsets expectation–maximization (OSEM) algorithm for determining contrast and semiquantitative indices of {sup 18}F-FDG uptake. Methods: The authors implemented SRT in the software for tomographic image reconstruction (STIR) open-source platform and evaluated this technique using simulated and real sinograms obtained from the GE Discovery ST positron emission tomography/computer tomography scanner. All simulations and reconstructions were performed in STIR. For OSEM, the authors used the clinical protocol of their scanner, namely, 21 subsets and two iterations. The authors also examined images at one, four, six, and ten iterations. For the simulation studies, the authors analyzed an image-quality phantom with cold and hot lesions. Two different versions of the phantom were employed at two different hot-sphere lesion-to-background ratios (LBRs), namely, 2:1 and 4:1. For each noiseless sinogram, 20 Poisson realizations were created at five different noise levels. In addition to making visual comparisons of the reconstructed images, the authors determined contrast and bias as a function of the background image roughness (IR). For the real-data studies, sinograms of an image-quality phantom simulating the human torso were employed. The authors determined contrast and LBR as a function of the background IR. Finally, the authors present plots of contrast as a function of IR after smoothing each reconstructed image with Gaussian filters of six different sizes. Statistical significance was determined by employing the Wilcoxon rank-sum test. Results: In both simulated and real studies, SRT

The SRT reconstruction algorithm for semiquantification in PET imaging

International Nuclear Information System (INIS)

Kastis, George A.; Gaitanis, Anastasios; Samartzis, Alexandros P.; Fokas, Athanasios S.

2015-01-01

Purpose: The spline reconstruction technique (SRT) is a new, fast algorithm based on a novel numerical implementation of an analytic representation of the inverse Radon transform. The mathematical details of this algorithm and comparisons with filtered backprojection were presented earlier in the literature. In this study, the authors present a comparison between SRT and the ordered-subsets expectation–maximization (OSEM) algorithm for determining contrast and semiquantitative indices of 18 F-FDG uptake. Methods: The authors implemented SRT in the software for tomographic image reconstruction (STIR) open-source platform and evaluated this technique using simulated and real sinograms obtained from the GE Discovery ST positron emission tomography/computer tomography scanner. All simulations and reconstructions were performed in STIR. For OSEM, the authors used the clinical protocol of their scanner, namely, 21 subsets and two iterations. The authors also examined images at one, four, six, and ten iterations. For the simulation studies, the authors analyzed an image-quality phantom with cold and hot lesions. Two different versions of the phantom were employed at two different hot-sphere lesion-to-background ratios (LBRs), namely, 2:1 and 4:1. For each noiseless sinogram, 20 Poisson realizations were created at five different noise levels. In addition to making visual comparisons of the reconstructed images, the authors determined contrast and bias as a function of the background image roughness (IR). For the real-data studies, sinograms of an image-quality phantom simulating the human torso were employed. The authors determined contrast and LBR as a function of the background IR. Finally, the authors present plots of contrast as a function of IR after smoothing each reconstructed image with Gaussian filters of six different sizes. Statistical significance was determined by employing the Wilcoxon rank-sum test. Results: In both simulated and real studies, SRT

Reconstruction of sound source signal by analytical passive TR in the environment with airflow

Science.gov (United States)

Wei, Long; Li, Min; Yang, Debin; Niu, Feng; Zeng, Wu

2017-03-01

In the acoustic design of air vehicles, the time-domain signals of noise sources on the surface of air vehicles can serve as data support to reveal the noise source generation mechanism, analyze acoustic fatigue, and take measures for noise insulation and reduction. To rapidly reconstruct the time-domain sound source signals in an environment with flow, a method combining the analytical passive time reversal mirror (AP-TR) with a shear flow correction is proposed. In this method, the negative influence of flow on sound wave propagation is suppressed by the shear flow correction, obtaining the corrected acoustic propagation time delay and path. Those corrected time delay and path together with the microphone array signals are then submitted to the AP-TR, reconstructing more accurate sound source signals in the environment with airflow. As an analytical method, AP-TR offers a supplementary way in 3D space to reconstruct the signal of sound source in the environment with airflow instead of the numerical TR. Experiments on the reconstruction of the sound source signals of a pair of loud speakers are conducted in an anechoic wind tunnel with subsonic airflow to validate the effectiveness and priorities of the proposed method. Moreover the comparison by theorem and experiment result between the AP-TR and the time-domain beamforming in reconstructing the sound source signal is also discussed.

Alternative reconstruction after pancreaticoduodenectomy

Directory of Open Access Journals (Sweden)

Cooperman Avram M

2008-01-01

Full Text Available Abstract Background Pancreaticoduodenectomy is the procedure of choice for tumors of the head of the pancreas and periampulla. Despite advances in surgical technique and postoperative care, the procedure continues to carry a high morbidity rate. One of the most common morbidities is delayed gastric emptying with rates of 15%–40%. Following two prolonged cases of delayed gastric emptying, we altered our reconstruction to avoid this complication altogether. Subsequently, our patients underwent a classic pancreaticoduodenectomy with an undivided Roux-en-Y technique for reconstruction. Methods We reviewed the charts of our last 13 Whipple procedures evaluating them for complications, specifically delayed gastric emptying. We compared the outcomes of those patients to a control group of 15 patients who underwent the Whipple procedure with standard reconstruction. Results No instances of delayed gastric emptying occurred in patients who underwent an undivided Roux-en-Y technique for reconstruction. There was 1 wound infection (8%, 1 instance of pneumonia (8%, and 1 instance of bleeding from the gastrojejunal staple line (8%. There was no operative mortality. Conclusion Use of the undivided Roux-en-Y technique for reconstruction following the Whipple procedure may decrease the incidence of delayed gastric emptying. In addition, it has the added benefit of eliminating bile reflux gastritis. Future randomized control trials are recommended to further evaluate the efficacy of the procedure.

Study of DNA reconstruction enzymes

Energy Technology Data Exchange (ETDEWEB)

Sekiguchi, M [Kyushu Univ., Fukuoka (Japan). Faculty of Science

1976-12-01

Description was made of the characteristics and mechanism of 3 reconstructive enzymes which received from M. luteus or E. coli or T4, and of which natures were clarified as reconstructive enzymes of DNA irradiated with ultraviolet rays. As characteristics, the site of breaking, reaction, molecular weight, electric charge in the neutrality and a specific adhesion to DNA irradiated with ultraviolet rays were mentioned. As to mutant of ultraviolet ray sensitivity, hereditary control mechanism of removal and reconstruction by endo-nuclease activation was described, and suggestion was referred to removal and reconstruction of cells of xedoderma pigmentosum which is a hereditary disease of human. Description was also made as to the mechanism of exonuclease activation which separates dimer selectively from irradiated DNA.

Reconstructing random media

International Nuclear Information System (INIS)

Yeong, C.L.; Torquato, S.

1998-01-01

We formulate a procedure to reconstruct the structure of general random heterogeneous media from limited morphological information by extending the methodology of Rintoul and Torquato [J. Colloid Interface Sci. 186, 467 (1997)] developed for dispersions. The procedure has the advantages that it is simple to implement and generally applicable to multidimensional, multiphase, and anisotropic structures. Furthermore, an extremely useful feature is that it can incorporate any type and number of correlation functions in order to provide as much morphological information as is necessary for accurate reconstruction. We consider a variety of one- and two-dimensional reconstructions, including periodic and random arrays of rods, various distribution of disks, Debye random media, and a Fontainebleau sandstone sample. We also use our algorithm to construct heterogeneous media from specified hypothetical correlation functions, including an exponentially damped, oscillating function as well as physically unrealizable ones. copyright 1998 The American Physical Society

Industrial dynamic tomographic reconstruction

International Nuclear Information System (INIS)

Oliveira, Eric Ferreira de

2016-01-01

The state of the art methods applied to industrial processes is currently based on the principles of classical tomographic reconstructions developed for tomographic patterns of static distributions, or is limited to cases of low variability of the density distribution function of the tomographed object. Noise and motion artifacts are the main problems caused by a mismatch in the data from views acquired in different instants. All of these add to the known fact that using a limited amount of data can result in the presence of noise, artifacts and some inconsistencies with the distribution under study. One of the objectives of the present work is to discuss the difficulties that arise from implementing reconstruction algorithms in dynamic tomography that were originally developed for static distributions. Another objective is to propose solutions that aim at reducing a temporal type of information loss caused by employing regular acquisition systems to dynamic processes. With respect to dynamic image reconstruction it was conducted a comparison between different static reconstruction methods, like MART and FBP, when used for dynamic scenarios. This comparison was based on a MCNPx simulation as well as an analytical setup of an aluminum cylinder that moves along the section of a riser during the process of acquisition, and also based on cross section images from CFD techniques. As for the adaptation of current tomographic acquisition systems for dynamic processes, this work established a sequence of tomographic views in a just-in-time fashion for visualization purposes, a form of visually disposing density information as soon as it becomes amenable to image reconstruction. A third contribution was to take advantage of the triple color channel necessary to display colored images in most displays, so that, by appropriately scaling the acquired values of each view in the linear system of the reconstruction, it was possible to imprint a temporal trace into the regularly

Intrinsic challenges in ancient microbiome reconstruction using 16S rRNA gene amplification.

Science.gov (United States)

Ziesemer, Kirsten A; Mann, Allison E; Sankaranarayanan, Krithivasan; Schroeder, Hannes; Ozga, Andrew T; Brandt, Bernd W; Zaura, Egija; Waters-Rist, Andrea; Hoogland, Menno; Salazar-García, Domingo C; Aldenderfer, Mark; Speller, Camilla; Hendy, Jessica; Weston, Darlene A; MacDonald, Sandy J; Thomas, Gavin H; Collins, Matthew J; Lewis, Cecil M; Hofman, Corinne; Warinner, Christina

2015-11-13

To date, characterization of ancient oral (dental calculus) and gut (coprolite) microbiota has been primarily accomplished through a metataxonomic approach involving targeted amplification of one or more variable regions in the 16S rRNA gene. Specifically, the V3 region (E. coli 341-534) of this gene has been suggested as an excellent candidate for ancient DNA amplification and microbial community reconstruction. However, in practice this metataxonomic approach often produces highly skewed taxonomic frequency data. In this study, we use non-targeted (shotgun metagenomics) sequencing methods to better understand skewed microbial profiles observed in four ancient dental calculus specimens previously analyzed by amplicon sequencing. Through comparisons of microbial taxonomic counts from paired amplicon (V3 U341F/534R) and shotgun sequencing datasets, we demonstrate that extensive length polymorphisms in the V3 region are a consistent and major cause of differential amplification leading to taxonomic bias in ancient microbiome reconstructions based on amplicon sequencing. We conclude that systematic amplification bias confounds attempts to accurately reconstruct microbiome taxonomic profiles from 16S rRNA V3 amplicon data generated using universal primers. Because in silico analysis indicates that alternative 16S rRNA hypervariable regions will present similar challenges, we advocate for the use of a shotgun metagenomics approach in ancient microbiome reconstructions.

Superheroes and supervillains: reconstructing the mad-scientist stereotype in school science

Science.gov (United States)

Avraamidou, Lucy

2013-04-01

Background. Reform recommendations around the world call for an understanding about the nature of science and the work of scientists. However, related research findings provide evidence that students hold stereotypical views of scientists and the nature of their work. Purpose The aim of this case study was to examine the impact of an intervention on 15 elementary school students' views of scientists. Sample An urban, fifth-grade, European elementary school classroom defined the context of this study. Design and method The intervention was an 11-week-long investigation of a local problem concerning water quality. In carrying out this investigation the students collaborated with a young metrology scientist to collect and analyse authentic data that would help them to construct a claim about the quality of the water. The students' initial views of scientists were investigated through a drawing activity, classroom discussions and interviews. Results Analysis of these data indicated that all students but one girl held very stereotypical views on scientists and the nature of their work. Analysis of interviews with each student and classroom discussions after the intervention illustrated that they reconstructed their stereotypical views of scientists and the nature of their work owing to their personal engagement in the investigation and their collaboration with the scientist. Conclusions The findings of this study suggest that more in-depth study into project-based approaches, out-of-school learning and school-scientist partnerships is warranted, for the purpose of determining appropriate pedagogies that support students in developing up-to-date understanding about scientists and the nature of their work.

[Pelvic reconstructions after bone tumor resection].

Science.gov (United States)

Anract, Philippe; Biau, David; Babinet, Antoine; Tomeno, Bernard

2014-02-01

The three more frequent primitive malignant bone tumour which concerned the iliac bone are chondrosarcoma, following Ewing sarcoma and osteosarcoma. Wide resection remains the most important part of the treatment associated with chemotherapy for osteosarcoma and the Ewing sarcoma. Iliac wing resections and obdurate ring don't required reconstruction. However, acetabular resections and iliac wing resection with disruption of the pelvic ring required reconstruction to provide acceptable functional result. Acetabular reconstruction remains high technical demanding challenge. After isolated acetabular resection or associated to obdurate ring, our usual method of reconstruction is homolateral proximal femoral autograft and total hip prosthesis but it is possible to also used : saddle prosthesis, Mac Minn prosthesis with auto or allograft, modular prosthesis or custom made prosthesis, massive allograft with or without prosthesis and femoro-ilac arthrodesis. After resection of the iliac wing plus acetabulum, reconstruction can be performed by femoro-obturatrice and femora-sacral arthrodesis, homolateral proximal femoral autograft and prosthesis, femoral medialisation, massive allograft and massive allograft. Carcinological results are lesser than resection for distal limb tumor, local recurrence rate range 17 to 45%. Functional results after Iliac wing and obdurate ring are good. However, acetabular reconstruction provide uncertain functional results. The lesser results arrive after hemipelvic or acetabular and iliac wing resection-reconstruction, especially when gluteus muscles were also resected. The most favourable results arrive after isolated acetabular or acetabular plus obturateur ring resection-reconstruction.

Cochlear implant-related three-dimensional characteristics determined by micro-computed tomography reconstruction.

Science.gov (United States)

Ni, Yusu; Dai, Peidong; Dai, Chunfu; Li, Huawei

2017-01-01

To explore the structural characteristics of the cochlea in three-dimensional (3D) detail using 3D micro-computed tomography (mCT) image reconstruction of the osseous labyrinth, with the aim of improving the structural design of electrodes, the selection of stimulation sites, and the effectiveness of cochlear implantation. Three temporal bones were selected from among adult donors' temporal bone specimens. A micro-CT apparatus (GE eXplore) was used to scan three specimens with a voxel resolution of 45 μm. We obtained about 460 slices/specimen, which produced abundant data. The osseous labyrinth images of three specimens were reconstructed from mCT. The cochlea and its spiral characteristics were measured precisely using Able Software 3D-DOCTOR. The 3D images of the osseous labyrinth, including the cochlea, vestibule, and semicircular canals, were reconstructed. The 3D models of the cochlea showed the spatial relationships and surface structural characteristics. Quantitative data concerning the cochlea and its spiral structural characteristics were analyzed with regard to cochlear implantation. The 3D reconstruction of mCT images clearly displayed the detailed spiral structural characteristics of the osseous labyrinth. Quantitative data regarding the cochlea and its spiral structural characteristics could help to improve electrode structural design, signal processing, and the effectiveness of cochlear implantation. Clin. Anat. 30:39-43, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Anterior Cranial Base Reconstruction with a Reverse Temporalis Muscle Flap and Calvarial Bone Graft

Directory of Open Access Journals (Sweden)

Seung Gee Kwon

2012-07-01

Full Text Available BackgroundCranial base defects are challenging to reconstruct without serious complications. Although free tissue transfer has been used widely and efficiently, it still has the limitation of requiring a long operation time along with the burden of microanastomosis and donor site morbidity. We propose using a reverse temporalis muscle flap and calvarial bone graft as an alternative option to a free flap for anterior cranial base reconstruction.MethodsBetween April 2009 and February 2012, cranial base reconstructions using an autologous calvarial split bone graft combined with a reverse temporalis muscle flap were performed in five patients. Medical records were retrospectively analyzed and postoperative computed tomography scans, magnetic resonance imaging, and angiography findings were examined to evaluate graft survival and flap viability.ResultsThe mean follow-up period was 11.8 months and the mean operation time for reconstruction was 8.4±3.36 hours. The defects involved the anterior cranial base, including the orbital roof and the frontal and ethmoidal sinus. All reconstructions were successful. Viable flap vascularity and bone survival were observed. There were no serious complications except for acceptable donor site depressions, which were easily corrected with minor procedures.ConclusionsThe reverse temporalis muscle flap could provide sufficient bulkiness to fill dead space and sufficient vascularity to endure infection. The calvarial bone graft provides a rigid framework, which is critical for maintaining the cranial base structure. Combined anterior cranial base reconstruction with a reverse temporalis muscle flap and calvarial bone graft could be a viable alternative to free tissue transfer.

Reconstruction of the democratic experience: democracy as a pedagogical belief in Dewey’s philosophy

OpenAIRE

Carina Tonieto; Altair Alberto Fávero

2012-01-01

The present article aims at reconstructing and analyzing the reasons that led the American educator John Dewey to elect democracy as the pedagogical belief of his educational philosophy. In order to do so, fi rstly our work will briefl y retrace the origins of democracy at the Greek paideia, in order to analyze the reasons that led Deweyto choose democracy as the main reference of his pedagogical belief. Finally, we will discuss the democratic concept of education on Dewey’s work Democracy an...

Iterative reconstruction reduces abdominal CT dose

International Nuclear Information System (INIS)

Martinsen, Anne Catrine Trægde; Sæther, Hilde Kjernlie; Hol, Per Kristian; Olsen, Dag Rune; Skaane, Per

2012-01-01

Objective: In medical imaging, lowering radiation dose from computed tomography scanning, without reducing diagnostic performance is a desired achievement. Iterative image reconstruction may be one tool to achieve dose reduction. This study reports the diagnostic performance using a blending of 50% statistical iterative reconstruction (ASIR) and filtered back projection reconstruction (FBP) compared to standard FBP image reconstruction at different dose levels for liver phantom examinations. Methods: An anthropomorphic liver phantom was scanned at 250, 185, 155, 140, 120 and 100 mA s, on a 64-slice GE Lightspeed VCT scanner. All scans were reconstructed with ASIR and FBP. Four readers evaluated independently on a 5-point scale 21 images, each containing 32 test sectors. In total 672 areas were assessed. ROC analysis was used to evaluate the differences. Results: There was a difference in AUC between the 250 mA s FBP images and the 120 and 100 mA s FBP images. ASIR reconstruction gave a significantly higher diagnostic performance compared to standard reconstruction at 100 mA s. Conclusion: A blending of 50–90% ASIR and FBP may improve image quality of low dose CT examinations of the liver, and thus give a potential for reducing radiation dose.

Image reconstruction by domain-transform manifold learning

Science.gov (United States)

Zhu, Bo; Liu, Jeremiah Z.; Cauley, Stephen F.; Rosen, Bruce R.; Rosen, Matthew S.

2018-03-01

Image reconstruction is essential for imaging applications across the physical and life sciences, including optical and radar systems, magnetic resonance imaging, X-ray computed tomography, positron emission tomography, ultrasound imaging and radio astronomy. During image acquisition, the sensor encodes an intermediate representation of an object in the sensor domain, which is subsequently reconstructed into an image by an inversion of the encoding function. Image reconstruction is challenging because analytic knowledge of the exact inverse transform may not exist a priori, especially in the presence of sensor non-idealities and noise. Thus, the standard reconstruction approach involves approximating the inverse function with multiple ad hoc stages in a signal processing chain, the composition of which depends on the details of each acquisition strategy, and often requires expert parameter tuning to optimize reconstruction performance. Here we present a unified framework for image reconstruction—automated transform by manifold approximation (AUTOMAP)—which recasts image reconstruction as a data-driven supervised learning task that allows a mapping between the sensor and the image domain to emerge from an appropriate corpus of training data. We implement AUTOMAP with a deep neural network and exhibit its flexibility in learning reconstruction transforms for various magnetic resonance imaging acquisition strategies, using the same network architecture and hyperparameters. We further demonstrate that manifold learning during training results in sparse representations of domain transforms along low-dimensional data manifolds, and observe superior immunity to noise and a reduction in reconstruction artefacts compared with conventional handcrafted reconstruction methods. In addition to improving the reconstruction performance of existing acquisition methodologies, we anticipate that AUTOMAP and other learned reconstruction approaches will accelerate the development

A Reduction of the Graph Reconstruction Conjecture

Directory of Open Access Journals (Sweden)

Monikandan S.

2014-08-01

Full Text Available A graph is said to be reconstructible if it is determined up to isomor- phism from the collection of all its one-vertex deleted unlabeled subgraphs. Reconstruction Conjecture (RC asserts that all graphs on at least three vertices are reconstructible. In this paper, we prove that interval-regular graphs and some new classes of graphs are reconstructible and show that RC is true if and only if all non-geodetic and non-interval-regular blocks G with diam(G = 2 or diam(Ḡ = diam(G = 3 are reconstructible

Reconstructing Topological Graphs and Continua

OpenAIRE

Gartside, Paul; Pitz, Max F.; Suabedissen, Rolf

2015-01-01

The deck of a topological space $X$ is the set $\\mathcal{D}(X)=\\{[X \\setminus \\{x\\}] \\colon x \\in X\\}$, where $[Z]$ denotes the homeomorphism class of $Z$. A space $X$ is topologically reconstructible if whenever $\\mathcal{D}(X)=\\mathcal{D}(Y)$ then $X$ is homeomorphic to $Y$. It is shown that all metrizable compact connected spaces are reconstructible. It follows that all finite graphs, when viewed as a 1-dimensional cell-complex, are reconstructible in the topological sense, and more genera...

Delayed breast implant reconstruction

DEFF Research Database (Denmark)

Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne

2012-01-01

We evaluated the association between radiation therapy and severe capsular contracture or reoperation after 717 delayed breast implant reconstruction procedures (288 1- and 429 2-stage procedures) identified in the prospective database of the Danish Registry for Plastic Surgery of the Breast during...... of radiation therapy was associated with a non-significantly increased risk of reoperation after both 1-stage (HR = 1.4; 95% CI: 0.7-2.5) and 2-stage (HR = 1.6; 95% CI: 0.9-3.1) procedures. Reconstruction failure was highest (13.2%) in the 2-stage procedures with a history of radiation therapy. Breast...... reconstruction approaches other than implants should be seriously considered among women who have received radiation therapy....

Variability in CT lung-nodule volumetry: Effects of dose reduction and reconstruction methods.

Science.gov (United States)

Young, Stefano; Kim, Hyun J Grace; Ko, Moe Moe; Ko, War War; Flores, Carlos; McNitt-Gray, Michael F

2015-05-01

Measuring the size of nodules on chest CT is important for lung cancer staging and measuring therapy response. 3D volumetry has been proposed as a more robust alternative to 1D and 2D sizing methods. There have also been substantial advances in methods to reduce radiation dose in CT. The purpose of this work was to investigate the effect of dose reduction and reconstruction methods on variability in 3D lung-nodule volumetry. Reduced-dose CT scans were simulated by applying a noise-addition tool to the raw (sinogram) data from clinically indicated patient scans acquired on a multidetector-row CT scanner (Definition Flash, Siemens Healthcare). Scans were simulated at 25%, 10%, and 3% of the dose of their clinical protocol (CTDIvol of 20.9 mGy), corresponding to CTDIvol values of 5.2, 2.1, and 0.6 mGy. Simulated reduced-dose data were reconstructed with both conventional filtered backprojection (B45 kernel) and iterative reconstruction methods (SAFIRE: I44 strength 3 and I50 strength 3). Three lab technologist readers contoured "measurable" nodules in 33 patients under each of the different acquisition/reconstruction conditions in a blinded study design. Of the 33 measurable nodules, 17 were used to estimate repeatability with their clinical reference protocol, as well as interdose and inter-reconstruction-method reproducibilities. The authors compared the resulting distributions of proportional differences across dose and reconstruction methods by analyzing their means, standard deviations (SDs), and t-test and F-test results. The clinical-dose repeatability experiment yielded a mean proportional difference of 1.1% and SD of 5.5%. The interdose reproducibility experiments gave mean differences ranging from -5.6% to -1.7% and SDs ranging from 6.3% to 9.9%. The inter-reconstruction-method reproducibility experiments gave mean differences of 2.0% (I44 strength 3) and -0.3% (I50 strength 3), and SDs were identical at 7.3%. For the subset of repeatability cases, inter-reconstruction

Artificial Intelligence-Based Student Learning Evaluation: A Concept Map-Based Approach for Analyzing a Student's Understanding of a Topic

Science.gov (United States)

Jain, G. Panka; Gurupur, Varadraj P.; Schroeder, Jennifer L.; Faulkenberry, Eileen D.

2014-01-01

In this paper, we describe a tool coined as artificial intelligence-based student learning evaluation tool (AISLE). The main purpose of this tool is to improve the use of artificial intelligence techniques in evaluating a student's understanding of a particular topic of study using concept maps. Here, we calculate the probability distribution of…

Compressed Sensing, Pseudodictionary-Based, Superresolution Reconstruction

Directory of Open Access Journals (Sweden)

Chun-mei Li

2016-01-01

Full Text Available The spatial resolution of digital images is the critical factor that affects photogrammetry precision. Single-frame, superresolution, image reconstruction is a typical underdetermined, inverse problem. To solve this type of problem, a compressive, sensing, pseudodictionary-based, superresolution reconstruction method is proposed in this study. The proposed method achieves pseudodictionary learning with an available low-resolution image and uses the K-SVD algorithm, which is based on the sparse characteristics of the digital image. Then, the sparse representation coefficient of the low-resolution image is obtained by solving the norm of l0 minimization problem, and the sparse coefficient and high-resolution pseudodictionary are used to reconstruct image tiles with high resolution. Finally, single-frame-image superresolution reconstruction is achieved. The proposed method is applied to photogrammetric images, and the experimental results indicate that the proposed method effectively increase image resolution, increase image information content, and achieve superresolution reconstruction. The reconstructed results are better than those obtained from traditional interpolation methods in aspect of visual effects and quantitative indicators.

Precipitation Reconstructions and Periods of Drought in the Upper Green River Basin, Wyoming, USA

Science.gov (United States)

Follum, M.; Barnett, A.; Bellamy, J.; Gray, S.; Tootle, G.

2008-12-01

Due to recent drought and stress on water supplies in the Colorado River Compact States, more emphasis has been placed on the study of water resources in the Upper Green River Basin (UGRB) of Wyoming, Utah, and Colorado. The research described here focuses on the creation of long-duration precipitation records for the UGRB using tree-ring chronologies. When combined with existing proxy streamflow reconstructions and drought frequency analysis, these records offer a detailed look at hydrologic variability in the UGRB. Approximately thirty-three existing tree ring chronologies were analyzed for the UGRB area. Several new tree ring chronologies were also developed to enhance the accuracy and the geographical diversity of the resulting tree-ring reconstructions. In total, three new Douglas-fir (Pseudotsuga menziesii) and four new limber pine (Pinus flexilis) sites were added to the available tree-ring chronologies in this area. Tree-ring based reconstructions of annual (previous July through current June) precipitation were then created for each of the seventeen sub-watersheds in the UGRB. Reconstructed precipitation records extend back to at least 1654 AD, with reconstructions for some sub-basins beginning pre-1500. Variance explained (i.e. adjusted R2) ranged from 0.41 to 0.74, and the reconstructions performed well in a variety of verification tests. Additional analyses focused on stochastic estimation of drought frequency and return period, and detailed comparisons between reconstructed records and instrumental observations. Overall, this work points to the prevalence of severe, widespread drought in the UGRB. These analyses also highlight the relative wetness and lack of sustained dry periods during the instrumental period (1895-Present). Such long- term assessments are, in turn, vital tools as the Compact States contemplate the "Law of the River" in the face of climate change and ever-growing water demands.

Hypothenar hammer syndrome: long-term results of vascular reconstruction.

Science.gov (United States)

Endress, Ryan D; Johnson, Craig H; Bishop, Allen T; Shin, Alexander Y

2015-04-01

To evaluate long-term patency rates and related outcomes after vascular reconstruction of hypothenar hammer syndrome and identify patient- or treatment-related factors that may contribute to differences in outcome. We used color flow ultrasound to determine the patency of 18 vein graft reconstructions of the ulnar artery at the wrist in 16 patients. Validated questionnaires evaluated patients' functional disability with the Disabilities of the Arm, Shoulder, and Hand score, pain with the visual analog scale, and cold intolerance with the Cold Intolerance Symptom Severity survey. Patient demographics, clinical data, and surgical factors were analyzed for association with graft failure. Patients were asked to grade the result of treatment on a scale of 0 to 10. Of 18 grafts, 14 (78%) were occluded at a mean of 118 months postoperatively. Patients with patent grafts had significantly less disability related to cold intolerance according to the Cold Intolerance Symptom Severity survey in addition to significantly less pain on the visual analog scale. There was no statistical difference in Disabilities of the Arm, Shoulder, and Hand scores between patients with patent or occluded grafts. Patients graded the result significantly higher in patent reconstructions. We noted a higher incidence of graft occlusion than previously reported at a mean follow-up of 9.8 years, which represents a long-duration follow-up study of surgical treatment of hypothenar hammer syndrome. Despite a high percentage of occlusion, overall, patients remained satisfied with low functional disability and all would recommend surgical reconstruction. This study suggests that improved outcomes may result from patent grafts in the long term. Prognostic IV. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Atmospheric inverse modeling via sparse reconstruction

Science.gov (United States)

Hase, Nils; Miller, Scot M.; Maaß, Peter; Notholt, Justus; Palm, Mathias; Warneke, Thorsten

2017-10-01

Many applications in atmospheric science involve ill-posed inverse problems. A crucial component of many inverse problems is the proper formulation of a priori knowledge about the unknown parameters. In most cases, this knowledge is expressed as a Gaussian prior. This formulation often performs well at capturing smoothed, large-scale processes but is often ill equipped to capture localized structures like large point sources or localized hot spots. Over the last decade, scientists from a diverse array of applied mathematics and engineering fields have developed sparse reconstruction techniques to identify localized structures. In this study, we present a new regularization approach for ill-posed inverse problems in atmospheric science. It is based on Tikhonov regularization with sparsity constraint and allows bounds on the parameters. We enforce sparsity using a dictionary representation system. We analyze its performance in an atmospheric inverse modeling scenario by estimating anthropogenic US methane (CH4) emissions from simulated atmospheric measurements. Different measures indicate that our sparse reconstruction approach is better able to capture large point sources or localized hot spots than other methods commonly used in atmospheric inversions. It captures the overall signal equally well but adds details on the grid scale. This feature can be of value for any inverse problem with point or spatially discrete sources. We show an example for source estimation of synthetic methane emissions from the Barnett shale formation.

Distributed MRI reconstruction using Gadgetron-based cloud computing.

Science.gov (United States)

Xue, Hui; Inati, Souheil; Sørensen, Thomas Sangild; Kellman, Peter; Hansen, Michael S

2015-03-01

To expand the open source Gadgetron reconstruction framework to support distributed computing and to demonstrate that a multinode version of the Gadgetron can be used to provide nonlinear reconstruction with clinically acceptable latency. The Gadgetron framework was extended with new software components that enable an arbitrary number of Gadgetron instances to collaborate on a reconstruction task. This cloud-enabled version of the Gadgetron was deployed on three different distributed computing platforms ranging from a heterogeneous collection of commodity computers to the commercial Amazon Elastic Compute Cloud. The Gadgetron cloud was used to provide nonlinear, compressed sensing reconstruction on a clinical scanner with low reconstruction latency (eg, cardiac and neuroimaging applications). The proposed setup was able to handle acquisition and 11 -SPIRiT reconstruction of nine high temporal resolution real-time, cardiac short axis cine acquisitions, covering the ventricles for functional evaluation, in under 1 min. A three-dimensional high-resolution brain acquisition with 1 mm(3) isotropic pixel size was acquired and reconstructed with nonlinear reconstruction in less than 5 min. A distributed computing enabled Gadgetron provides a scalable way to improve reconstruction performance using commodity cluster computing. Nonlinear, compressed sensing reconstruction can be deployed clinically with low image reconstruction latency. © 2014 Wiley Periodicals, Inc.

The RAVE/VERTIGO vertex reconstruction toolkit and framework

Energy Technology Data Exchange (ETDEWEB)

Waltenberger, W; Mitaroff, W; Moser, F; Pflugfelder, B; Riedel, H V [Austrian Academy of Sciences, Institute of High Energy Physics, A-1050 Vienna (Austria)], E-mail: walten@hephy.oeaw.ac.at

2008-07-15

A detector-independent toolkit for vertex reconstruction (RAVE{sup 1}) is being developed, along with a standalone framework (VERTIGO{sup 2}) for testing, analyzing and debugging. The core algorithms represent state-of-the-art for geometric vertex finding and fitting by both linear (Kalman filter) and robust estimation methods. Main design goals are ease of use, flexibility for embedding into existing software frameworks, extensibility, and openness. The implementation is based on modern object-oriented techniques, is coded in C++ with interfaces for Java and Python, and follows an open-source approach. A beta release is available.

Surface Reconstruction from Parallel Curves with Application to Parietal Bone Fracture Reconstruction.

Directory of Open Access Journals (Sweden)

Abdul Majeed

Full Text Available Maxillofacial trauma are common, secondary to road traffic accident, sports injury, falls and require sophisticated radiological imaging to precisely diagnose. A direct surgical reconstruction is complex and require clinical expertise. Bio-modelling helps in reconstructing surface model from 2D contours. In this manuscript we have constructed the 3D surface using 2D Computerized Tomography (CT scan contours. The fracture part of the cranial vault are reconstructed using GC1 rational cubic Ball curve with three free parameters, later the 2D contours are flipped into 3D with equidistant z component. The constructed surface is represented by contours blending interpolant. At the end of this manuscript a case report of parietal bone fracture is also illustrated by employing this method with a Graphical User Interface (GUI illustration.

Orbital Reconstruction: Patient-Specific Orbital Floor Reconstruction Using a Mirroring Technique and a Customized Titanium Mesh.

Science.gov (United States)

Tarsitano, Achille; Badiali, Giovanni; Pizzigallo, Angelo; Marchetti, Claudio

2016-10-01

Enophthalmos is a severe complication of primary reconstruction of orbital floor fractures. The goal of secondary reconstruction procedures is to restore symmetrical globe positions to recover function and aesthetics. The authors propose a new method of orbital floor reconstruction using a mirroring technique and a customized titanium mesh, printed using a direct metal laser-sintering method. This reconstructive protocol involves 4 steps: mirroring of the healthy orbit at the affected site, virtual design of a patient-specific orbital floor mesh, CAM procedures for direct laser-sintering of the customized titanium mesh, and surgical insertion of the device. Using a computed tomography data set, the normal, uninjured side of the craniofacial skeleton was reflected onto the contralateral injured side, and a reconstructive orbital floor mesh was designed virtually on the mirrored orbital bone surface. The solid-to-layer files of the mesh were then manufactured using direct metal laser sintering, which resolves the shaping and bending biases inherent in the indirect method. An intraoperative navigation system ensured accuracy of the entire procedure. Clinical outcomes were assessed using 3dMD photogrammetry and computed tomography data in 7 treated patients. The technique described here appears to be a viable method to correct complex orbital floor defects needing delayed reconstruction. This study represents the first step in the development of a wider experimental protocol for orbital floor reconstruction using computer-assisted design-computer-assisted manufacturing technology.

3-D image reconstruction in radiology

International Nuclear Information System (INIS)

Grangeat, P.

1999-01-01

In this course, we present highlights on fully 3-D image reconstruction algorithms used in 3-D X-ray Computed Tomography (3-D-CT) and 3-D Rotational Radiography (3-D-RR). We first consider the case of spiral CT with a one-row detector. Starting from the 2-D fan-beam inversion formula for a circular trajectory, we introduce spiral CT 3-D image reconstruction algorithm using axial interpolation for each transverse slice. In order to improve the X-ray detection efficiency and to speed the acquisition process, the future is to use multi-row detectors associated with small angle cone-beam geometry. The generalization of the 2-D fan-beam image reconstruction algorithm to cone beam defined direct inversion formula referred as Feldkamp's algorithm for a circular trajectory and Wang's algorithm for a spiral trajectory. However, large area detectors does exist such as Radiological Image Intensifiers or in a near future solid state detectors. To get a larger zoom effect, it defines a cone-beam geometry associated with a large aperture angle. For this case, we introduce indirect image reconstruction algorithm by plane re-binning in the Radon domain. We will present some results from a prototype MORPHOMETER device using the RADON reconstruction software. Lastly, we consider the special case of 3-D Rotational Digital Subtraction Angiography with a restricted number of views. We introduce constraint optimization algorithm using quadratic, entropic or half-quadratic constraints. Generalized ART (Algebraic Reconstruction Technique) iterative reconstruction algorithm can be derived from the Bregman algorithm. We present reconstructed vascular trees from a prototype MORPHOMETER device. (author)

CT imaging of congenital lung lesions: effect of iterative reconstruction on diagnostic performance and radiation dose

International Nuclear Information System (INIS)

Haggerty, Jay E.; Smith, Ethan A.; Dillman, Jonathan R.; Kunisaki, Shaun M.

2015-01-01

Different iterative reconstruction techniques are available for use in pediatric computed tomography (CT), but these techniques have not been systematically evaluated in infants. To determine the effect of iterative reconstruction on diagnostic performance, image quality and radiation dose in infants undergoing CT evaluation for congenital lung lesions. A retrospective review of contrast-enhanced chest CT in infants (<1 year) with congenital lung lesions was performed. CT examinations were reviewed to document the type of lung lesion, vascular anatomy, image noise measurements and image reconstruction method. CTDI vol was used to calculate size-specific dose estimates (SSDE). CT findings were correlated with intraoperative and histopathological findings. Analysis of variance and the Student's t-test were used to compare image noise measurements and radiation dose estimates between groups. Fifteen CT examinations used filtered back projection (FBP; mean age: 84 days), 15 used adaptive statistical iterative reconstruction (ASiR; mean age: 93 days), and 11 used model-based iterative reconstruction (MBIR; mean age: 98 days). Compared to operative findings, 13/15 (87%), 14/15 (93%) and 11/11 (100%) lesions were correctly characterized using FBP, ASiR and MBIR, respectively. Arterial anatomy was correctly identified in 12/15 (80%) using FBP, 13/15 (87%) using ASiR and 11/11 (100%) using MBIR. Image noise was less for MBIR vs. ASiR (P < 0.0001). Mean SSDE was different among groups (P = 0.003; FBP = 7.35 mGy, ASiR = 1.89 mGy, MBIR = 1.49 mGy). Congenital lung lesions can be adequately characterized in infants using iterative CT reconstruction techniques while maintaining image quality and lowering radiation dose. (orig.)

CT imaging of congenital lung lesions: effect of iterative reconstruction on diagnostic performance and radiation dose

Energy Technology Data Exchange (ETDEWEB)

Haggerty, Jay E.; Smith, Ethan A.; Dillman, Jonathan R. [University of Michigan Health System, Section of Pediatric Radiology, Department of Radiology, C.S. Mott Children' s Hospital, Ann Arbor, MI (United States); Kunisaki, Shaun M. [University of Michigan Health System, Section of Pediatric Surgery, Department of Surgery, C.S. Mott Children' s Hospital, Ann Arbor, MI (United States)

2015-07-15

Different iterative reconstruction techniques are available for use in pediatric computed tomography (CT), but these techniques have not been systematically evaluated in infants. To determine the effect of iterative reconstruction on diagnostic performance, image quality and radiation dose in infants undergoing CT evaluation for congenital lung lesions. A retrospective review of contrast-enhanced chest CT in infants (<1 year) with congenital lung lesions was performed. CT examinations were reviewed to document the type of lung lesion, vascular anatomy, image noise measurements and image reconstruction method. CTDI{sub vol} was used to calculate size-specific dose estimates (SSDE). CT findings were correlated with intraoperative and histopathological findings. Analysis of variance and the Student's t-test were used to compare image noise measurements and radiation dose estimates between groups. Fifteen CT examinations used filtered back projection (FBP; mean age: 84 days), 15 used adaptive statistical iterative reconstruction (ASiR; mean age: 93 days), and 11 used model-based iterative reconstruction (MBIR; mean age: 98 days). Compared to operative findings, 13/15 (87%), 14/15 (93%) and 11/11 (100%) lesions were correctly characterized using FBP, ASiR and MBIR, respectively. Arterial anatomy was correctly identified in 12/15 (80%) using FBP, 13/15 (87%) using ASiR and 11/11 (100%) using MBIR. Image noise was less for MBIR vs. ASiR (P < 0.0001). Mean SSDE was different among groups (P = 0.003; FBP = 7.35 mGy, ASiR = 1.89 mGy, MBIR = 1.49 mGy). Congenital lung lesions can be adequately characterized in infants using iterative CT reconstruction techniques while maintaining image quality and lowering radiation dose. (orig.)

iCN718, an Updated and Improved Genome-Scale Metabolic Network Reconstruction of Acinetobacter baumannii AYE.

Science.gov (United States)

Norsigian, Charles J; Kavvas, Erol; Seif, Yara; Palsson, Bernhard O; Monk, Jonathan M

2018-01-01

Acinetobacter baumannii has become an urgent clinical threat due to the recent emergence of multi-drug resistant strains. There is thus a significant need to discover new therapeutic targets in this organism. One means for doing so is through the use of high-quality genome-scale reconstructions. Well-curated and accurate genome-scale models (GEMs) of A. baumannii would be useful for improving treatment options. We present an updated and improved genome-scale reconstruction of A. baumannii AYE, named iCN718, that improves and standardizes previous A. baumannii AYE reconstructions. iCN718 has 80% accuracy for predicting gene essentiality data and additionally can predict large-scale phenotypic data with as much as 89% accuracy, a new capability for an A. baumannii reconstruction. We further demonstrate that iCN718 can be used to analyze conserved metabolic functions in the A. baumannii core genome and to build strain-specific GEMs of 74 other A. baumannii strains from genome sequence alone. iCN718 will serve as a resource to integrate and synthesize new experimental data being generated for this urgent threat pathogen.

Análise dos indicadores de gestão das IFES e o desempenho discente no ENADE Analyzing management indexes of Federal Universities against students' performance at ENADE

Directory of Open Access Journals (Sweden)

Glauber de Castro Barbosa

2011-07-01

Full Text Available Em nível mundial há uma tendência de avaliação do ensino superior, considerando-se aspectos institucionais e de desempenho discente. No Brasil, o tema tem sido debatido há algum tempo com processos concretos de avaliação sendo implantados recentemente. As Instituições Federais de Ensino Superior (IFES estão sendo avaliadas por meio de indicadores de gestão propostos pelo Tribunal de Contas da União (TCU. Por outro lado, o desempenho discente de graduandos está sendo avaliado através do Exame Nacional de Desempenho dos Estudantes (ENADE. De certa forma, os indicadores de gestão podem ser instrumentos adicionais de apoio para a gestão de IFES. O objetivo deste trabalho é analisar possíveis relações entre indicadores de gestão e desempenho discente. Para tanto, pesquisou-se uma amostra de 52 IFES no período de 2006 a 2008. Os resultados indicam que, de fato, alguns indicadores de gestão parecem ser capazes de influenciar o desempenho discente. Este é o caso, por exemplo, do custo por aluno que apresentou um efeito positivo sobre o desempenho dos alunos.There a trend toward the evaluation of higher education in many countries, taking into account institutional management and student performance. In Brazil, the topic has been debated for some time with concrete evaluation experiences recently. Federal Universities (IFES are evaluated through management indexes proposed by TCU (Federal Court of Audit. Meanwhile, students are evaluated by ENADE (National Examination of Student Performance. In a certain way, management indexes may be additional instruments for IFES management. The purpose of this work is analyzing possible relations between management indexes and students' performance at ENADE. We have analyzed a sample of 52 IFES in the period 2006-2008. Results signal that, indeed, some management indexes seem to be able to influence students' performance. This is the case, for example, of the cost by student that has shown a

No economic benefit of early knee reconstruction over optional delayed reconstruction for ACL tears

DEFF Research Database (Denmark)

Kiadaliri, Aliasghar A; Englund, Martin; Stefan Lohmander, L.

2016-01-01

Background To analyse 5-year cost-effectiveness of early versus optional delayed acute anterior cruciate ligament (ACL) reconstruction. Methods 121 young, active adults with acute ACL injury to a previously uninjured knee were randomised to early ACL reconstruction (n=62, within 10 weeks of injur...

Controversies in orbital reconstruction-III. Biomaterials for orbital reconstruction : a review with clinical recommendations

NARCIS (Netherlands)

Dubois, L.; Steenen, S. A.; Gooris, P. J. J.; Bos, R. R. M.; Becking, A. G.

The goal of orbital reconstruction is to repair trauma defects, to correct the position of the eye anatomically, avoiding enophthalmos, and to restore ocular function. For the reconstruction of (trauma) defects, many surgeons recommend materials that can be bent into an anatomical shape and that

Breast reconstruction and post-mastectomy radiation practice

International Nuclear Information System (INIS)

Chen, Susie A; Hiley, Crispin; Nickleach, Dana; Petsuksiri, Janjira; Andic, Fundagul; Riesterer, Oliver; Switchenko, Jeffrey M; Torres, Mylin A

2013-01-01

The goal of this study was to explore the perspectives and practice of radiation oncologists who treat breast cancer patients who have had breast reconstruction. In 2010, an original electronic survey was sent to all physician members of the American Society of Radiation Oncology, National Cancer Research Institute-Breast Cancer Studies Group in the United Kingdom, Thai Society of Therapeutic Radiology and Oncology, Swiss Society of Radiation Oncology, and Turkish Radiation Oncology Society. We identified factors associated with radiation oncologists who treat breast cancer patients with reconstruction performed prior to radiation and obtained information regarding radiation management of the breast reconstruction. 358 radiation oncologists responded, and 60% of the physicians were from the United States. While 64% of participants agree or strongly agree that breast image affects a woman’s quality of life during radiation, 57% feel that reconstruction challenges their ability to deliver effective breast radiation. Compared with other countries, treatment within the United States was associated with a high reconstruction rate (>/= 50% of mastectomy patients) prior to radiation (p < 0.05). Delayed-immediate reconstruction with a temporary tissue expander was more common in the United States than in other countries (52% vs. 23%, p = 0.01). Among physicians who treat patients with tissue expanders, the majority (60%) prefer a moderately inflated implant with 150-250 cc of fluid rather than a completely deflated (13%) or inflated expander (28%) during radiation. Among radiation oncologists who treat reconstructions, 49% never use bolus and 40% never boost a breast reconstruction. United States physicians were more likely than physicians from other countries to boost or bolus the reconstruction irrespective of the type of reconstruction seen in their clinic patients (p < 0.01). Great variation in practice is evident from our study of radiation treatment for breast

Boomerang flap reconstruction for the breast.

Science.gov (United States)

Baumholtz, Michael A; Al-Shunnar, Buthainah M; Dabb, Richard W

2002-07-01

The boomerang-shaped latissimus dorsi musculocutaneous flap for breast reconstruction offers a stable platform for breast reconstruction. It allows for maximal aesthetic results with minimal complications. The authors describe a skin paddle to obtain a larger volume than either the traditional elliptical skin paddle or the extended latissimus flap. There are three specific advantages to the boomerang design: large volume, conical shape (often lacking in the traditional skin paddle), and an acceptable donor scar. Thirty-eight flaps were performed. No reconstruction interfered with patient's ongoing oncological regimen. The most common complication was seroma, which is consistent with other latissimus reconstructions.

Analysis of algebraic reconstruction technique for accurate imaging of gas temperature and concentration based on tunable diode laser absorption spectroscopy

International Nuclear Information System (INIS)

Xia Hui-Hui; Kan Rui-Feng; Liu Jian-Guo; Xu Zhen-Yu; He Ya-Bai

2016-01-01

An improved algebraic reconstruction technique (ART) combined with tunable diode laser absorption spectroscopy(TDLAS) is presented in this paper for determining two-dimensional (2D) distribution of H 2 O concentration and temperature in a simulated combustion flame. This work aims to simulate the reconstruction of spectroscopic measurements by a multi-view parallel-beam scanning geometry and analyze the effects of projection rays on reconstruction accuracy. It finally proves that reconstruction quality dramatically increases with the number of projection rays increasing until more than 180 for 20 × 20 grid, and after that point, the number of projection rays has little influence on reconstruction accuracy. It is clear that the temperature reconstruction results are more accurate than the water vapor concentration obtained by the traditional concentration calculation method. In the present study an innovative way to reduce the error of concentration reconstruction and improve the reconstruction quality greatly is also proposed, and the capability of this new method is evaluated by using appropriate assessment parameters. By using this new approach, not only the concentration reconstruction accuracy is greatly improved, but also a suitable parallel-beam arrangement is put forward for high reconstruction accuracy and simplicity of experimental validation. Finally, a bimodal structure of the combustion region is assumed to demonstrate the robustness and universality of the proposed method. Numerical investigation indicates that the proposed TDLAS tomographic algorithm is capable of detecting accurate temperature and concentration profiles. This feasible formula for reconstruction research is expected to resolve several key issues in practical combustion devices. (paper)

Additive manufacturing technology in reconstructive surgery.

Science.gov (United States)

Fuller, Scott C; Moore, Michael G

2016-10-01

Technological advances have been part and parcel of modern reconstructive surgery, in that practitioners of this discipline are continually looking for innovative ways to perfect their craft and improve patient outcomes. We are currently in a technological climate wherein advances in computers, imaging, and science have coalesced with resulting innovative breakthroughs that are not merely limited to improved outcomes and enhanced patient care, but may provide novel approaches to training the next generation of reconstructive surgeons. New developments in software and modeling platforms, imaging modalities, tissue engineering, additive manufacturing, and customization of implants are poised to revolutionize the field of reconstructive surgery. The interface between technological advances and reconstructive surgery continues to expand. Additive manufacturing techniques continue to evolve in an effort to improve patient outcomes, decrease operative time, and serve as instructional tools for the training of reconstructive surgeons.

Multi-slice spiral CT coronary angiography: influence of heart rate and reconstruction window on image quality

International Nuclear Information System (INIS)

Mao Dingbiao; Hua Yanqing; Wang Mingpeng; Zhang Guozhen; Wu Weilan; Hu Fei; Ge Xiaojun; Ding Qiyong

2004-01-01

Objective: To evaluate the influence of heart rate and reconstruction window on image quality of multi-slice spiral CT coronary angiography. Methods: Retrospectively ECG-gated MSCT coronary angiography were performed in 80 healthy cases. Results: Four coronary (RCA, LM, LAD, LCX) segments were analyzed in each patient with regard to image quality. 82.1% (46/56) of the coronary segments were sufficient for analysis in patients with heart rate ≤60 bpm, 63.4% (104/164) with 61-70 bpm, 41.2%(28/68) with 71-80 bpm, and 31.2%(10/32) with>80 bpm, respectively. The left anterior descending artery, left circumflex artery, and the right coronary artery were best visualized when the reconstruction window was 60%-70%, 50%-60%, and 50%-70%, respectively. Conclusion: Image quality of MSCT coronary angiography is highly dependent on heart rate and reconstruction window

Progressive Reconstruction: A Methodology for Stabilization and Reconstruction Operations

National Research Council Canada - National Science Library

Rohr, Karl C

2006-01-01

... these nations in accordance with stated United States' goals. The argument follows closely current and developing United States military doctrine on stabilization, reconstruction, and counterinsurgency operations...

Titanium template for scaphoid reconstruction.

Science.gov (United States)

Haefeli, M; Schaefer, D J; Schumacher, R; Müller-Gerbl, M; Honigmann, P

2015-06-01

Reconstruction of a non-united scaphoid with a humpback deformity involves resection of the non-union followed by bone grafting and fixation of the fragments. Intraoperative control of the reconstruction is difficult owing to the complex three-dimensional shape of the scaphoid and the other carpal bones overlying the scaphoid on lateral radiographs. We developed a titanium template that fits exactly to the surfaces of the proximal and distal scaphoid poles to define their position relative to each other after resection of the non-union. The templates were designed on three-dimensional computed tomography reconstructions and manufactured using selective laser melting technology. Ten conserved human wrists were used to simulate the reconstruction. The achieved precision measured as the deviation of the surface of the reconstructed scaphoid from its virtual counterpart was good in five cases (maximal difference 1.5 mm), moderate in one case (maximal difference 3 mm) and inadequate in four cases (difference more than 3 mm). The main problems were attributed to the template design and can be avoided by improved pre-operative planning, as shown in a clinical case. © The Author(s) 2014.

Dynamic dual-tracer PET reconstruction.

Science.gov (United States)

Gao, Fei; Liu, Huafeng; Jian, Yiqiang; Shi, Pengcheng

2009-01-01

Although of important medical implications, simultaneous dual-tracer positron emission tomography reconstruction remains a challenging problem, primarily because the photon measurements from dual tracers are overlapped. In this paper, we propose a simultaneous dynamic dual-tracer reconstruction of tissue activity maps based on guidance from tracer kinetics. The dual-tracer reconstruction problem is formulated in a state-space representation, where parallel compartment models serve as continuous-time system equation describing the tracer kinetic processes of dual tracers, and the imaging data is expressed as discrete sampling of the system states in measurement equation. The image reconstruction problem has therefore become a state estimation problem in a continuous-discrete hybrid paradigm, and H infinity filtering is adopted as the estimation strategy. As H infinity filtering makes no assumptions on the system and measurement statistics, robust reconstruction results can be obtained for the dual-tracer PET imaging system where the statistical properties of measurement data and system uncertainty are not available a priori, even when there are disturbances in the kinetic parameters. Experimental results on digital phantoms, Monte Carlo simulations and physical phantoms have demonstrated the superior performance.

Colon dissection: a new three-dimensional reconstruction tool for computed tomography colonography

International Nuclear Information System (INIS)

Roettgen, R.; Fischbach, F.; Plotkin, M.; Herzog, H.; Freund, T.; Schroeder, R. J.; Felix, R.

2005-01-01

Purpose: To improve the sensitivity of computed tomography (CT) colonography in the detection of polyps by comparing the 3D reconstruction tool 'colon dissection' and endoluminal view (virtual colonoscopy) with axial 2D reconstructions. Material and Methods: Forty-eight patients (22 M, 26 F, mean age 57±21) were studied after intra-anal air insufflation in the supine and prone positions using a 16-slice helical CT (16x0.625 mm, pitch 1.7; detector rotation time 0.5 s; 160 mAs und 120 kV) and conventional colonoscopy. Two radiologists blinded to the results of the conventional colonoscopy analyzed the 3D reconstruction in virtual-endoscopy mode, in colon-dissection mode, and axial 2D slices. Results: Conventional colonoscopy revealed a total of 35 polyps in 15 patients; 33 polyps were disclosed by CT methods. Sensitivity and specificity for detecting colon polyps were 94% and 94%, respectively, when using the 'colon dissection', 89% and 94% when using 'virtual endoscopy', and 62% and 100% when using axial 2D reconstruction. Sensitivity in relation to the diameter of colon polyps with 'colon dissection', 'virtual colonoscopy', and axial 2D-slices was: polyps with a diameter >5.0 mm, 100%, 100%, and 71%, respectively; polyps with a diameter of between 3 and 4.9 mm, 92%, 85%, and 46%; and polyps with a diameter <3 mm, 89%, 78%, and 56%. The difference between 'virtual endoscopy' and 'colon dissection' in diagnosing polyps up to 4.9 mm in diameter was statistically significant. Conclusion: 3D reconstruction software 'colon dissection' improves sensitivity of CT colonography compared with the endoluminal view

Connected Filtering by Reconstruction : Basis and New Advances

NARCIS (Netherlands)

Wilkinson, Michael H.F.

2008-01-01

Openings-by-reconstruction are the oldest connected filters, and indeed, reconstruction methodology lies at the heart of many connected operators such as levelings. Starting out from the basic reconstruction principle of iterated geodesic dilations, extensions such as the use of reconstruction

CONNECTED FILTERING BY RECONSTRUCTION : BASIS AND NEW ADVANCES

NARCIS (Netherlands)

Wilkinson, Michael H. F.

2008-01-01

Openings-by-reconstruction are the oldest connected filters, and indeed, reconstruction methodology lies at the heart of many connected operators such as levelings. Starting out from the basic reconstruction principle of iterated geodesic dilations, extensions such as the use of reconstruction

Design patterns for instructional materials that foster proficiency at analyzing and interpreting complex geoscience data

Science.gov (United States)

Kastens, K. A.; Krumhansl, R.

2016-12-01

The Next Generation Science Standards incorporate a stronger emphasis on having students work with data than did prior standards. This emphasis is most obvious in Practice 4: Analyzing and Interpreting Data, but also permeates performance expectations built on Practice 2 when students test models, Practice 6 when students construct explanations, and Practice 7 when student test claims with evidence. To support curriculum developers who wish to guide high school students towards more sophisticated engagement with complex data, we analyzed a well-regarded body of instructional materials designed for use in introductory college courses (http://serc.carleton.edu/integrate/teaching_materials/). Our analysis sought design patterns that can be reused for a variety of topics at the high school or college level. We found five such patterns, each of which was used in at least half of the modules analyzed. We describe each pattern, provide an example, and hypothesize a theory of action that could explain how the sequence of activities leverages known perceptual, cognitive and/or social processes to foster learning from and about data. In order from most to least frequent, the observed design patterns are as follows: In Data Puzzles, students respond to guiding questions about high-value snippets of data pre-selected and sequenced by the curriculum developer to lead to an Aha! inference. In Pooling Data to See the Big Picture, small groups analyze different instances of analogous phenomenon (e.g. different hurricanes, or different divergent plate boundaries) and pool their insights to extract the commonalities that constitute the essence of that phenomenon. In Make a Decision or Recommendation, students combine geoscience data with other factors (such as economic or environmental justice concerns) to make a decision or recommendation about a human or societal action. In Predict-Observe-Explain, students make a prediction about what the Earth will look like under conditions

Document reconstruction by layout analysis of snippets

Science.gov (United States)

Kleber, Florian; Diem, Markus; Sablatnig, Robert

2010-02-01

Document analysis is done to analyze entire forms (e.g. intelligent form analysis, table detection) or to describe the layout/structure of a document. Also skew detection of scanned documents is performed to support OCR algorithms that are sensitive to skew. In this paper document analysis is applied to snippets of torn documents to calculate features for the reconstruction. Documents can either be destroyed by the intention to make the printed content unavailable (e.g. tax fraud investigation, business crime) or due to time induced degeneration of ancient documents (e.g. bad storage conditions). Current reconstruction methods for manually torn documents deal with the shape, inpainting and texture synthesis techniques. In this paper the possibility of document analysis techniques of snippets to support the matching algorithm by considering additional features are shown. This implies a rotational analysis, a color analysis and a line detection. As a future work it is planned to extend the feature set with the paper type (blank, checked, lined), the type of the writing (handwritten vs. machine printed) and the text layout of a snippet (text size, line spacing). Preliminary results show that these pre-processing steps can be performed reliably on a real dataset consisting of 690 snippets.

Tomographic reconstruction of binary fields

International Nuclear Information System (INIS)

Roux, Stéphane; Leclerc, Hugo; Hild, François

2012-01-01

A novel algorithm is proposed for reconstructing binary images from their projection along a set of different orientations. Based on a nonlinear transformation of the projection data, classical back-projection procedures can be used iteratively to converge to the sought image. A multiscale implementation allows for a faster convergence. The algorithm is tested on images up to 1 Mb definition, and an error free reconstruction is achieved with a very limited number of projection data, saving a factor of about 100 on the number of projections required for classical reconstruction algorithms.

Reconstruction in oral malignancy: Factors affecting morbidity of various procedures

Science.gov (United States)

Chakrabarti, Suvadip; Chakrabarti, Preeti Rihal; Desai, Sanjay M.; Agrawal, Deepak; Mehta, Dharmendra Y.; Pancholi, Mayank

2015-01-01

Aims and Objective: (1) To study the age and sex distribution of patient with oral malignancies. (2) To analyze various types of surgery performed. (3) Evaluation of reconstruction and factors affecting complications and its relation to the type of reconstruction. Materials and Methods: Cases of oral malignancies, undergoing surgery for the same in Sri Aurobindo Medical College and PG Institute, Indore from the period from October 1, 2012, to March 31, 2015. Results: Out of analysis of 111 cases of oral malignancy, 31 (27.9%) cases were in the fifth decade of life with male to female ratio 1.9:1. The commonest site of cancer was buccal mucosa. Forty-seven cases (43.2%) were in stage IVa. Diabetes was the most common co-morbidity reported, accounting for 53.9% of cases with reported morbidity. Tobacco chewing was the common entity in personal habits. All the cases underwent neck dissection along with resection of the primary. Hemimandibulectomy was the most preferred form of primary resection accounting for 53.15% (59 cases), followed by wide resection of primary 27% (30 cases). Pectoralis major myocutaneous (PMMC) flap only was the most common reconstruction across the study population. PMMC alone accounted for 38.7% (43 cases). The infection rate was 16.21%. PMMC alone accounted for 5 out of 18 (27.8%) of total infection rate, and 4.5% of the total study population. PMMC + deltopectoral accounted for 5 out of 18 (27.8%) of total infection rate, and 4.5% of the total study population. Conclusion: PMMC is a major workhorse for reconstruction with better functional outcome and acceptance among operated patients. PMID:26981469

Self-expressive Dictionary Learning for Dynamic 3D Reconstruction.

Science.gov (United States)

Zheng, Enliang; Ji, Dinghuang; Dunn, Enrique; Frahm, Jan-Michael

2017-08-22

We target the problem of sparse 3D reconstruction of dynamic objects observed by multiple unsynchronized video cameras with unknown temporal overlap. To this end, we develop a framework to recover the unknown structure without sequencing information across video sequences. Our proposed compressed sensing framework poses the estimation of 3D structure as the problem of dictionary learning, where the dictionary is defined as an aggregation of the temporally varying 3D structures. Given the smooth motion of dynamic objects, we observe any element in the dictionary can be well approximated by a sparse linear combination of other elements in the same dictionary (i.e. self-expression). Our formulation optimizes a biconvex cost function that leverages a compressed sensing formulation and enforces both structural dependency coherence across video streams, as well as motion smoothness across estimates from common video sources. We further analyze the reconstructability of our approach under different capture scenarios, and its comparison and relation to existing methods. Experimental results on large amounts of synthetic data as well as real imagery demonstrate the effectiveness of our approach.

Reconstruction and restoration of historical buildings of transport infrastructure

Science.gov (United States)

Kareeva, Daria; Glazkova, Valeriya

2017-10-01

The aim of this article is to identify the main problems in the restoration of the historical objects. For this reason, it is rationally to collect and analyze the existing world experience of restoration. The information which was put together showed that there are some problems which are common and can be solved. In addition, the protection of the Monuments of Culture and Architecture Comittees always makes the restoration and reconstruction of the historical buildings complicated. By the examples of Germany, Italy and Russia it is shown that there are problems in organization, economy, planning and control. Engineers should think of and justify the methodology of organizing and monitoring of the restoration of the historical buildings. As a second solution, it will be possible to minimize time and financial costs through a favorable financial and legal background for investors and through the creation of a system of restoration work organizing. And for a faster process of restoration the imitation programs should be optimized for research and selection of the reconstruction technological and economic methods.

Four-Dimensional Patient Dose Reconstruction for Scanned Ion Beam Therapy of Moving Liver Tumors

International Nuclear Information System (INIS)

Richter, Daniel; Saito, Nami; Chaudhri, Naved; Härtig, Martin; Ellerbrock, Malte; Jäkel, Oliver; Combs, Stephanie E.; Habermehl, Daniel; Herfarth, Klaus; Durante, Marco; Bert, Christoph

2014-01-01

Purpose: Estimation of the actual delivered 4-dimensional (4D) dose in treatments of patients with mobile hepatocellular cancer with scanned carbon ion beam therapy. Methods and Materials: Six patients were treated with 4 fractions to a total relative biological effectiveness (RBE)–weighted dose of 40 Gy (RBE) using a single field. Respiratory motion was addressed by dedicated margins and abdominal compression (5 patients) or gating (1 patient). 4D treatment dose reconstructions based on the treatment records and the measured motion monitoring data were performed for the single-fraction dose and a total of 17 fractions. To assess the impact of uncertainties in the temporal correlation between motion trajectory and beam delivery sequence, 3 dose distributions for varying temporal correlation were calculated per fraction. For 3 patients, the total treatment dose was formed from the fractional distributions using all possible combinations. Clinical target volume (CTV) coverage was analyzed using the volumes receiving at least 95% (V 95 ) and 107% (V 107 ) of the planned doses. Results: 4D dose reconstruction based on daily measured data is possible in a clinical setting. V 95 and V 107 values for the single fractions ranged between 72% and 100%, and 0% and 32%, respectively. The estimated total treatment dose to the CTV exhibited improved and more robust dose coverage (mean V 95 > 87%, SD < 3%) and overdose (mean V 107 < 4%, SD < 3%) with respect to the single-fraction dose for all analyzed patients. Conclusions: A considerable impact of interplay effects on the single-fraction CTV dose was found for most of the analyzed patients. However, due to the fractionated treatment, dose heterogeneities were substantially reduced for the total treatment dose. 4D treatment dose reconstruction for scanned ion beam therapy is technically feasible and may evolve into a valuable tool for dose assessment

Neutrophil-lymphocyte ratio and platelet-lymphocyte ratio as predictors of wound healing failure in head and neck reconstruction.

Science.gov (United States)

Maruyama, Yoko; Inoue, Keita; Mori, Keita; Gorai, Katsuya; Shimamoto, Ryo; Onitsuka, Tetsuro; Iguchi, Hiroyoshi; Okazaki, Mutsumi; Nakagawa, Masahiro

2017-01-01

In microsurgical head and neck reconstruction, a higher rate of post-operative wound complication could be predicted by a lower pre-operative neutrophil ratio (wound complications in microsurgical head and neck reconstruction. Patients who were undergoing tumor ablation and microsurgical reconstruction from April 2011 to March 2014 were analyzed retrospectively. The pre-operative hematological data, age, sex, co-morbidities, body mass index (BMI), adjuvant therapies, smoking, operation time, blood loss, total protein, T-stage, and Anesthesiologists Performance Status (ASA-PS) score were collected. Cases of post-operative wound healing failure were reviewed. One hundred and three consecutive patients were enrolled. Among these, the results of 77 patients who were younger than 70 years of age were analyzed. The distributions of the neutrophil ratio (p = .0005), lymphocyte ratio (p = .0166), monocyte ratio (p = .0341), NLR (p = .005), and PLR (p = .008) differed significantly between the patients with and without post-operative wound healing failure. Neutrophil ratio, NLR, and PLR cut-off values of 64.9, 3.5, and 160 were significantly associated with the rate of wound healing failure rate (p = .0002, .00021, .0042, respectively).

Causal-Comparative Study Analyzing Student Success in Hybrid Anatomy and Physiology Courses

Science.gov (United States)

Levy, Jacqueline Anita

2013-01-01

In the biological sciences, higher student success levels are achieved in traditionally formatted, face-to-face coursework than in hybrid courses. The methodologies used to combine hybrid and in-person elements to the course need to be applied to the biological sciences to emulate the success seen in the traditional courses since the number of…

Labral reconstruction: when to perform and how

Directory of Open Access Journals (Sweden)

Brian J White

2015-07-01

Full Text Available Over the past decade, the understanding of the anatomy and function of the hip joint has continuously evolved, and surgical treatment options for the hip have significantly progressed. Originally, surgical treatment of the hip primarily involved resection of damaged tissue. Procedures that maintain and preserve proper hip anatomy, such as labral repair and femoroacetabular impingement (FAI correction, have shown superior results, in terms of pain reduction, increased function, and ability to return to activities. Labral reconstruction is a treatment option that uses a graft to reconstruct the native labrum. The technique and outcomes of labral reconstruction have been described relatively recently, and labral reconstruction is a cutting edge procedure that has shown promising early outcomes. The aim of this article is to review the current literature on hip labral reconstruction. We will review the indications for labral reconstruction, surgical technique and graft options, and surgical outcomes that have been described to date. Labral reconstruction provides an alternative treatment option for challenging intra-articular hip problems. Labral reconstruction restores the original anatomy of the hip and has the potential to preserve the longevity of the hip joint. This technique is an important tool in the orthopaedic surgeon’s arsenal for hip joint treatment and preservation.

CURRENT CONCEPTS IN ACL RECONSTRUCTION

Directory of Open Access Journals (Sweden)

Freddie H. Fu

2008-09-01

Full Text Available Current Concepts in ACL Reconstruction is a complete reference text composed of the most thorough collection of topics on the ACL and its surgical reconstruction compiled, with contributions from some of the world's experts and most experienced ACL surgeons. Various procedures mentioned throughout the text are also demonstrated in an accompanying video CD-ROM. PURPOSE Composing a single, comprehensive and complete information source on ACL including basic sciences, clinical issues, latest concepts and surgical techniques, from evaluation to outcome, from history to future, editors and contributors have targeted to keep the audience pace with the latest concepts and techniques for the evaluation and the treatment of ACL injuries. FEATURES The text is composed of 27 chapters in 6 sections. The first section is mostly about basic sciences, also history of the ACL, imaging, clinical approach to adolescent and pediatric patients are subjected. In the second section, Graft Choices and Arthroscopy Portals for ACL Reconstruction are mentioned. The third section is about the technique and the outcome of the single-bundle ACL reconstruction. The fourth chapter includes the techniques and outcome of the double-bundle ACL reconstruction. In the fifth chapter revision, navigation technology, rehabilitation and the evaluation of the outcome of ACL reconstruction is subjected. The sixth/the last chapter is about the future advances to reach: What We Have Learned and the Future of ACL Reconstruction. AUDIENCE Orthopedic residents, sports traumatology and knee surgery fellows, orthopedic surgeons, also scientists in basic sciences or clinicians who are studying or planning a research on ACL forms the audience group of this book. ASSESSMENT This is the latest, the most complete and comprehensive textbook of ACL reconstruction produced by the editorial work up of two pioneer and masters "Freddie H. Fu MD and Steven B. Cohen MD" with the contribution of world

Effects of Different Reconstruction Parameters on CT Volumetric Measurement 
of Pulmonary Nodules

Directory of Open Access Journals (Sweden)

Rongrong YANG

2012-02-01

Full Text Available Background and objective It has been proven that volumetric measurements could detect subtle changes in small pulmonary nodules in serial CT scans, and thus may play an important role in the follow-up of indeterminate pulmonary nodules and in differentiating malignant nodules from benign nodules. The current study aims to evaluate the effects of different reconstruction parameters on the volumetric measurements of pulmonary nodules in chest CT scans. Methods Thirty subjects who underwent chest CT scan because of indeterminate pulmonary nodules in General Hospital of Tianjin Medical University from December 2009 to August 2011 were retrospectively analyzed. A total of 52 pulmonary nodules were included, and all CT data were reconstructed using three reconstruction algorithms and three slice thicknesses. The volumetric measurements of the nodules were performed using the advanced lung analysis (ALA software. The effects of the reconstruction algorithms, slice thicknesses, and nodule diameters on the volumetric measurements were assessed using the multivariate analysis of variance for repeated measures, the correlation analysis, and the Bland-Altman method. Results The reconstruction algorithms (F=13.6, P<0.001 and slice thicknesses (F=4.4, P=0.02 had significant effects on the measured volume of pulmonary nodules. In addition, the coefficients of variation of nine measurements were inversely related with nodule diameter (r=-0.814, P<0.001. The volume measured at the 2.5 mm slice thickness had poor agreement with the volumes measured at 1.25 mm and 0.625 mm, respectively. Moreover, the best agreement was achieved between the slice thicknesses of 1.25 mm and 0.625 mm using the bone algorithm. Conclusion Reconstruction algorithms and slice thicknesses have significant impacts on the volumetric measurements of lung nodules, especially for the small nodules. Therefore, the reconstruction setting in serial CT scans should be consistent in the follow

Biological Reconstruction Following the Resection of Malignant Bone Tumors of the Pelvis

Directory of Open Access Journals (Sweden)

Frank Traub

2013-01-01

Full Text Available Background. Surgical treatment of malignant pelvic bone tumors can be very challenging. The objective of this retrospective study was to evaluate the oncological as well as the clinical and functional outcome after limb salvage surgery and biological reconstruction. Methods. The files of 27 patients with malignant pelvic bone tumors, who underwent surgical resection at our department between 2000 and 2011, were retrospectively analyzed (9 Ewing's sarcoma, 8 chondrosarcoma, 4 osteosarcoma, 1 synovial sarcoma, 1 malignant fibrous histiocytoma, and 4 carcinoma metastases. Results. After internal hemipelvectomy reconstruction was performed by hip transposition (, using autologous nonvascularised fibular graft ( or autologous iliac crest bone graft (. In one patient a proximal femor prothetis and in three patients a total hip prosthesis was implanted at the time of resection. The median follow-up was 33 months. Two- and five-year disease-specific survival rates of all patients were 86.1% and 57.7%, respectively. The mean functional MSTS score was 16.5 (~55% for all patients. Conclusion. On the basis of the oncological as well as the clinical and functional outcome, biological reconstruction after internal hemipelvectomy seems to be a reliable technique for treating patients with a malignant pelvic bone tumor.

Climate Reconstructions

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Paleoclimatology Program archives reconstructions of past climatic conditions derived from paleoclimate proxies, in addition to the Program's large holdings...

SU-E-I-86: Ultra-Low Dose Computed Tomography Attenuation Correction for Pediatric PET CT Using Adaptive Statistical Iterative Reconstruction (ASiR™)

Energy Technology Data Exchange (ETDEWEB)

Brady, S; Shulkin, B [St. Jude Children’s Research Hospital, Memphis, TN (United States)

2015-06-15

Purpose: To develop ultra-low dose computed tomography (CT) attenuation correction (CTAC) acquisition protocols for pediatric positron emission tomography CT (PET CT). Methods: A GE Discovery 690 PET CT hybrid scanner was used to investigate the change to quantitative PET and CT measurements when operated at ultra-low doses (10–35 mAs). CT quantitation: noise, low-contrast resolution, and CT numbers for eleven tissue substitutes were analyzed in-phantom. CT quantitation was analyzed to a reduction of 90% CTDIvol (0.39/3.64; mGy) radiation dose from baseline. To minimize noise infiltration, 100% adaptive statistical iterative reconstruction (ASiR) was used for CT reconstruction. PET images were reconstructed with the lower-dose CTAC iterations and analyzed for: maximum body weight standardized uptake value (SUVbw) of various diameter targets (range 8–37 mm), background uniformity, and spatial resolution. Radiation organ dose, as derived from patient exam size specific dose estimate (SSDE), was converted to effective dose using the standard ICRP report 103 method. Effective dose and CTAC noise magnitude were compared for 140 patient examinations (76 post-ASiR implementation) to determine relative patient population dose reduction and noise control. Results: CT numbers were constant to within 10% from the non-dose reduced CTAC image down to 90% dose reduction. No change in SUVbw, background percent uniformity, or spatial resolution for PET images reconstructed with CTAC protocols reconstructed with ASiR and down to 90% dose reduction. Patient population effective dose analysis demonstrated relative CTAC dose reductions between 62%–86% (3.2/8.3−0.9/6.2; mSv). Noise magnitude in dose-reduced patient images increased but was not statistically different from pre dose-reduced patient images. Conclusion: Using ASiR allowed for aggressive reduction in CTAC dose with no change in PET reconstructed images while maintaining sufficient image quality for co

Top reconstruction and boosted top experimental overview

CERN Document Server

Skinnari, Louise

2015-01-01

An overview of techniques used to reconstruct resolved and boosted top quarks is presented. Techniques for resolved top quark reconstruction include kinematic likelihood fitters and pseudo- top reconstruction. Many tools and methods are available for the reconstruction of boosted top quarks, such as jet grooming techniques, jet substructure variables, and dedicated top taggers. Different techniques as used by ATLAS and CMS analyses are described and the performance of different variables and top taggers are shown.

Medical image reconstruction. A conceptual tutorial

International Nuclear Information System (INIS)

Zeng, Gengsheng Lawrence

2010-01-01

''Medical Image Reconstruction: A Conceptual Tutorial'' introduces the classical and modern image reconstruction technologies, such as two-dimensional (2D) parallel-beam and fan-beam imaging, three-dimensional (3D) parallel ray, parallel plane, and cone-beam imaging. This book presents both analytical and iterative methods of these technologies and their applications in X-ray CT (computed tomography), SPECT (single photon emission computed tomography), PET (positron emission tomography), and MRI (magnetic resonance imaging). Contemporary research results in exact region-of-interest (ROI) reconstruction with truncated projections, Katsevich's cone-beam filtered backprojection algorithm, and reconstruction with highly undersampled data with l 0 -minimization are also included. (orig.)

Reconstruction design before tumour resection: A new concept of through-and-through cheek defect reconstruction.

Science.gov (United States)

Gong, Zhao-Jian; Ren, Zhen-Hu; Wang, Kai; Tan, Hong-Yu; Zhang, Sheng; Wu, Han-Jiang

2017-11-01

To explore a new method of reconstruction of through-and-through cheek defects and to evaluate this method's efficacy and patient prognosis. This retrospective study included 70 patients who underwent reconstruction of through-and-through cheek defects. The surgical approach, design of facial skin incisions, selection and design of flaps, postoperative quality of life and prognosis of patients were recorded and reported. Postoperative quality of life gradually increased over time, and the mean scores of University of Washington Quality of Life (UW-QOL) Questionnaire was more than 80 at 1-year postoperatively. The appearance, oral competence, chewing, swallowing, speech and other oral functions were well recovered in about 90% of patients at 1-year postoperatively. This new idea of reconstruction before tumour resection, brings the effect of plastic and reconstructive surgery to a new height. Copyright © 2017. Published by Elsevier Ltd.

Reconstruction of dynamic structures of experimental setups based on measurable experimental data only

Science.gov (United States)

Chen, Tian-Yu; Chen, Yang; Yang, Hu-Jiang; Xiao, Jing-Hua; Hu, Gang

2018-03-01

Nowadays, massive amounts of data have been accumulated in various and wide fields, it has become today one of the central issues in interdisciplinary fields to analyze existing data and extract as much useful information as possible from data. It is often that the output data of systems are measurable while dynamic structures producing these data are hidden, and thus studies to reveal system structures by analyzing available data, i.e., reconstructions of systems become one of the most important tasks of information extractions. In the past, most of the works in this respect were based on theoretical analyses and numerical verifications. Direct analyses of experimental data are very rare. In physical science, most of the analyses of experimental setups were based on the first principles of physics laws, i.e., so-called top-down analyses. In this paper, we conducted an experiment of “Boer resonant instrument for forced vibration” (BRIFV) and inferred the dynamic structure of the experimental set purely from the analysis of the measurable experimental data, i.e., by applying the bottom-up strategy. Dynamics of the experimental set is strongly nonlinear and chaotic, and itʼs subjects to inevitable noises. We proposed to use high-order correlation computations to treat nonlinear dynamics; use two-time correlations to treat noise effects. By applying these approaches, we have successfully reconstructed the structure of the experimental setup, and the dynamic system reconstructed with the measured data reproduces good experimental results in a wide range of parameters.

Considerations on Xi- reconstruction in LHCb

CERN Document Server

Brochu, F.M.

2016-01-01

This paper describes an alternative method of charged hyperon reconstruction applicable to the LHCb experiment. It extends the seminal work of the FOCUS collaboration to the specific detector layout of LHCb and addresses the reconstruction ambiguities reported in their earlier work, leading to improvements in the reconstruction efficiency for the specific cases of Xi- and Omega- baryon decays to a charged meson and a Lambda baryon.

A biomechanical modeling-guided simultaneous motion estimation and image reconstruction technique (SMEIR-Bio) for 4D-CBCT reconstruction

Science.gov (United States)

Huang, Xiaokun; Zhang, You; Wang, Jing

2018-02-01

Reconstructing four-dimensional cone-beam computed tomography (4D-CBCT) images directly from respiratory phase-sorted traditional 3D-CBCT projections can capture target motion trajectory, reduce motion artifacts, and reduce imaging dose and time. However, the limited numbers of projections in each phase after phase-sorting decreases CBCT image quality under traditional reconstruction techniques. To address this problem, we developed a simultaneous motion estimation and image reconstruction (SMEIR) algorithm, an iterative method that can reconstruct higher quality 4D-CBCT images from limited projections using an inter-phase intensity-driven motion model. However, the accuracy of the intensity-driven motion model is limited in regions with fine details whose quality is degraded due to insufficient projection number, which consequently degrades the reconstructed image quality in corresponding regions. In this study, we developed a new 4D-CBCT reconstruction algorithm by introducing biomechanical modeling into SMEIR (SMEIR-Bio) to boost the accuracy of the motion model in regions with small fine structures. The biomechanical modeling uses tetrahedral meshes to model organs of interest and solves internal organ motion using tissue elasticity parameters and mesh boundary conditions. This physics-driven approach enhances the accuracy of solved motion in the organ’s fine structures regions. This study used 11 lung patient cases to evaluate the performance of SMEIR-Bio, making both qualitative and quantitative comparisons between SMEIR-Bio, SMEIR, and the algebraic reconstruction technique with total variation regularization (ART-TV). The reconstruction results suggest that SMEIR-Bio improves the motion model’s accuracy in regions containing small fine details, which consequently enhances the accuracy and quality of the reconstructed 4D-CBCT images.

Nonlinear optimal filter technique for analyzing energy depositions in TES sensors driven into saturation

Directory of Open Access Journals (Sweden)

B. Shank

2014-11-01

Full Text Available We present a detailed thermal and electrical model of superconducting transition edge sensors (TESs connected to quasiparticle (qp traps, such as the W TESs connected to Al qp traps used for CDMS (Cryogenic Dark Matter Search Ge and Si detectors. We show that this improved model, together with a straightforward time-domain optimal filter, can be used to analyze pulses well into the nonlinear saturation region and reconstruct absorbed energies with optimal energy resolution.