Keep Counting Those Boxes--There's More.

ERIC Educational Resources Information Center

Mingus, Tabitha T. Y.; Grassl, Richard M.

1998-01-01

Poses and solves several related extensions involving enumerating squares and rectangles. Describes how problem extensions can be developed and used in the classroom to motivate and challenge teachers and students to exert themselves mathematically. (ASK)

Multi-object segmentation using coupled nonparametric shape and relative pose priors

NASA Astrophysics Data System (ADS)

Uzunbas, Mustafa Gökhan; Soldea, Octavian; Çetin, Müjdat; Ünal, Gözde; Erçil, Aytül; Unay, Devrim; Ekin, Ahmet; Firat, Zeynep

2009-02-01

We present a new method for multi-object segmentation in a maximum a posteriori estimation framework. Our method is motivated by the observation that neighboring or coupling objects in images generate configurations and co-dependencies which could potentially aid in segmentation if properly exploited. Our approach employs coupled shape and inter-shape pose priors that are computed using training images in a nonparametric multi-variate kernel density estimation framework. The coupled shape prior is obtained by estimating the joint shape distribution of multiple objects and the inter-shape pose priors are modeled via standard moments. Based on such statistical models, we formulate an optimization problem for segmentation, which we solve by an algorithm based on active contours. Our technique provides significant improvements in the segmentation of weakly contrasted objects in a number of applications. In particular for medical image analysis, we use our method to extract brain Basal Ganglia structures, which are members of a complex multi-object system posing a challenging segmentation problem. We also apply our technique to the problem of handwritten character segmentation. Finally, we use our method to segment cars in urban scenes.

Group Work Tests for Context-Rich Problems

ERIC Educational Resources Information Center

Meyer, Chris

2016-01-01

The group work test is an assessment strategy that promotes higher-order thinking skills for solving context-rich problems. With this format, teachers are able to pose challenging, nuanced questions on a test, while providing the support weaker students need to get started and show their understanding. The test begins with a group discussion…

Introductory Economic Geography: Problem-Solving or a Teaching Problem?

ERIC Educational Resources Information Center

Wheeler, James O.

Because economic geography is viewed as a field with too many different aspects for one person to master, teaching an introductory course in the subject poses the challenge of selecting an organizing theme. One specific approach, organized around higher level generalizations and theories, is the use of location theory. Coupling location theory…

Taking the Incredible Years Child and Teacher Programs to Scale in Wales

ERIC Educational Resources Information Center

Hutchings, Judy; Williams, Margiad Elen

2017-01-01

Students who demonstrate conduct problems pose ongoing challenges for teachers. Therefore, prevention programs that all families and teachers of young children can use to promote social and emotional learning, emotion regulation, and problem solving are of great interest to researchers and practitioners alike. This article describes the Incredible…

Robust Radio Broadcast Monitoring Using a Multi-Band Spectral Entropy Signature

NASA Astrophysics Data System (ADS)

Camarena-Ibarrola, Antonio; Chávez, Edgar; Tellez, Eric Sadit

Monitoring media broadcast content has deserved a lot of attention lately from both academy and industry due to the technical challenge involved and its economic importance (e.g. in advertising). The problem pose a unique challenge from the pattern recognition point of view because a very high recognition rate is needed under non ideal conditions. The problem consist in comparing a small audio sequence (the commercial ad) with a large audio stream (the broadcast) searching for matches.

Chess from Square a1: Incorporating Chess into the Gifted Class

ERIC Educational Resources Information Center

Adams, Thomasina C. P.

2012-01-01

Teachers of gifted students often are challenged to find ways to stimulate critical thinking and problem-solving skills. School chess clubs are one way of meeting that challenge. This article poses how games such as chess affect learning and gifted students. Two detailed strategies for teaching chess to students beginning in kindergarten are…

Antibiotic resistance: a physicist’s view

NASA Astrophysics Data System (ADS)

Allen, Rosalind; Waclaw, Bartłomiej

2016-08-01

The problem of antibiotic resistance poses challenges across many disciplines. One such challenge is to understand the fundamental science of how antibiotics work, and how resistance to them can emerge. This is an area where physicists can make important contributions. Here, we highlight cases where this is already happening, and suggest directions for further physics involvement in antimicrobial research.

Responding to the Challenge: Giving Pre-Service Classroom Teachers a Musical Language and Understanding

ERIC Educational Resources Information Center

Munday, Jenni; Smith, Wyverne

2010-01-01

Pre-service teacher degree programs are increasingly crowded with subjects covering the wide gamut of knowledge a teacher requires. Ensuring musical knowledge and language for classroom teaching poses a difficult problem for teacher educators. This article examines the challenges of including in the pre-service classroom teaching program a music…

Challenges and Induction Needs of Novice English as a Foreign Language Teachers in Saudi Arabia

ERIC Educational Resources Information Center

Alhamad, Rufaida

2018-01-01

The first year of teaching poses massive challenges that lead to attrition among novice teachers. School communities often fail to provide adequate support to novice teachers to help them adapt to their new professional environments. In Saudi Arabia, attrition among novice teachers is a significant problem that hinders the development of the…

A study on facial expressions recognition

NASA Astrophysics Data System (ADS)

Xu, Jingjing

2017-09-01

In terms of communication, postures and facial expressions of such feelings like happiness, anger and sadness play important roles in conveying information. With the development of the technology, recently a number of algorithms dealing with face alignment, face landmark detection, classification, facial landmark localization and pose estimation have been put forward. However, there are a lot of challenges and problems need to be fixed. In this paper, a few technologies have been concluded and analyzed, and they all relate to handling facial expressions recognition and poses like pose-indexed based multi-view method for face alignment, robust facial landmark detection under significant head pose and occlusion, partitioning the input domain for classification, robust statistics face formalization.

Finding Ways to Effectively Prevent Sexual Abuse by Youth

ERIC Educational Resources Information Center

Klein, Alisa; Tabachnick, Joan

2002-01-01

Youth with sexual behavior problems pose a complicated challenge to the society. Yet the society has succeeded in developing only a limited range of actions and attitudes to grapple with and prevent this problem. Very few of the social service and criminal justice systems have rallied to create compassionate models that not only address and…

Exploring a Structure for Mathematics Lessons That Foster Problem Solving and Reasoning

ERIC Educational Resources Information Center

Sullivan, Peter; Walker, Nadia; Borcek, Chris; Rennie, Mick

2015-01-01

While there is widespread agreement on the importance of incorporating problem solving and reasoning into mathematics classrooms, there is limited specific advice on how this can best happen. This is a report of an aspect of a project that is examining the opportunities and constraints in initiating learning by posing challenging mathematics tasks…

Problem Posing in Leadership Education: Using Case Study to Foster More Effective Problem Solving

ERIC Educational Resources Information Center

Myran, Steve; Sutherland, Ian

2016-01-01

This case explores Crabapple Middle, a struggling urban school in the midst of a transition that seeks new leadership that can overcome the challenges of two sub-cultures that divide the school and community. In an effort to address issues of low academic performance and negative community perception, an International Baccalaureate magnet program…

A Tale of Three Cases: Examining Accuracy, Efficiency, and Process Differences in Diagnosing Virtual Patient Cases

ERIC Educational Resources Information Center

Doleck, Tenzin; Jarrell, Amanda; Poitras, Eric G.; Chaouachi, Maher; Lajoie, Susanne P.

2016-01-01

Clinical reasoning is a central skill in diagnosing cases. However, diagnosing a clinical case poses several challenges that are inherent to solving multifaceted ill-structured problems. In particular, when solving such problems, the complexity stems from the existence of multiple paths to arriving at the correct solution (Lajoie, 2003). Moreover,…

Instructional Strategies for Online Introductory College Physics Based on Learning Styles

ERIC Educational Resources Information Center

Ekwue, Eleazer U.

2013-01-01

The practical nature of physics and its reliance on mathematical presentations and problem solving pose a challenge toward presentation of the course in an online environment for effective learning experience. Most first-time introductory college physics students fail to grasp the basic concepts of the course and the problem solving skills if the…

A Framework for Representing and Jointly Reasoning over Linguistic and Non-Linguistic Knowledge

ERIC Educational Resources Information Center

Murugesan, Arthi

2009-01-01

Natural language poses several challenges to developing computational systems for modeling it. Natural language is not a precise problem but is rather ridden with a number of uncertainties in the form of either alternate words or interpretations. Furthermore, natural language is a generative system where the problem size is potentially infinite.…

Technological Innovation of Higher Education in New Zealand: A Wicked Problem?

ERIC Educational Resources Information Center

Marshall, Stephen

2016-01-01

New Zealand, like many countries, faces the challenge of building and sustaining an educated population. Particular challenges are posed by the need to educate an increasing proportion of the population to higher levels in order to support the growth of a modern skills and knowledge economy, as opposed to an economy built on low-cost labour and…

Double-blind, placebo-controlled food challenge in adults in everyday clinical practice: a reappraisal of their limitations and real indications.

PubMed

Asero, Riccardo; Fernandez-Rivas, Montserrat; Knulst, André C; Bruijnzeel-Koomen, Carla Afm

2009-08-01

The double-blind, placebo-controlled food challenge (DBPCFC) is widely considered as the 'gold standard' for the diagnosis of food allergy. However, in adult patients, this procedure is rather rarely performed outside the academic context. This review article aims to reappraise the pros and cons of DBPCFC and to elicit some critical thoughts and discussions about the real indications of this diagnostic procedure in adult patients in everyday practice. There are many data showing that the DBPCFC poses a number of critical problems that are difficult to overcome in normal outpatient clinics and hospitals, and that are generally not addressed in most articles dealing with this issue. Performing DBPCFC poses a number of practical problems and has several pitfalls, which make its routine use in normal clinical settings generally impossible. This review article shows that the need for this procedure in adult patients seems in effect very little and specifies new, more limited indications to its use in everyday practice. Further, it suggests a role for the open challenge, which lacks several of the disadvantages of DBPCFC.

Body Parts Dependent Joint Regressors for Human Pose Estimation in Still Images.

PubMed

Dantone, Matthias; Gall, Juergen; Leistner, Christian; Van Gool, Luc

2014-11-01

In this work, we address the problem of estimating 2d human pose from still images. Articulated body pose estimation is challenging due to the large variation in body poses and appearances of the different body parts. Recent methods that rely on the pictorial structure framework have shown to be very successful in solving this task. They model the body part appearances using discriminatively trained, independent part templates and the spatial relations of the body parts using a tree model. Within such a framework, we address the problem of obtaining better part templates which are able to handle a very high variation in appearance. To this end, we introduce parts dependent body joint regressors which are random forests that operate over two layers. While the first layer acts as an independent body part classifier, the second layer takes the estimated class distributions of the first one into account and is thereby able to predict joint locations by modeling the interdependence and co-occurrence of the parts. This helps to overcome typical ambiguities of tree structures, such as self-similarities of legs and arms. In addition, we introduce a novel data set termed FashionPose that contains over 7,000 images with a challenging variation of body part appearances due to a large variation of dressing styles. In the experiments, we demonstrate that the proposed parts dependent joint regressors outperform independent classifiers or regressors. The method also performs better or similar to the state-of-the-art in terms of accuracy, while running with a couple of frames per second.

Problems and challenges in patient information retrieval: a descriptive study.

PubMed Central

Kogan, S.; Zeng, Q.; Ash, N.; Greenes, R. A.

2001-01-01

Many patients now turn to the Web for health care information. However, a lack of domain knowledge and unfamiliarity with medical vocabulary and concepts restrict their ability to successfully obtain information they seek. The purpose of this descriptive study was to identify and classify the problems a patient encounters while performing information retrieval tasks on the Web, and the challenges it poses to informatics research. In this study, we observed patients performing various retrieval tasks, and measured the effectiveness of, satisfaction with, and usefulness of the results. Our study showed that patient information retrieval often failed to produce successful results due to a variety of problems. We propose a classification of patient IR problems based on our observations. PMID:11825205

The Relationship between Students' Problem Posing and Problem Solving Abilities and Beliefs: A Small-Scale Study with Chinese Elementary School Children

ERIC Educational Resources Information Center

Limin, Chen; Van Dooren, Wim; Verschaffel, Lieven

2013-01-01

The goal of the present study is to investigate the relationship between pupils' problem posing and problem solving abilities, their beliefs about problem posing and problem solving, and their general mathematics abilities, in a Chinese context. Five instruments, i.e., a problem posing test, a problem solving test, a problem posing questionnaire,…

Laboratory Based Case Studies: Closer to the Real World

ERIC Educational Resources Information Center

Dinan, Frank J.

2005-01-01

Case-based laboratories offer students the chance to approximate real science. Based on interesting stories that pose problems requiring experimental solutions, they avoid the cookbook approach characteristic of traditional undergraduate laboratory instruction. Instead, case-based laboratories challenge students to develop, as much as possible,…

Restoring Scholarship to Collegiate Mathematics.

ERIC Educational Resources Information Center

Steen, Lynn Arthur

1986-01-01

Needs of collegiate mathematics across the nation are considered, and suggestions are offered to the National Science Foundation (NSF) by a professor of Mathematics at St. Olaf College (Minnesota). Changes in mathematics content, scope, and applications have implications for the college curriculum. Problems and challenges are posed by: increased…

Voice Enabled Framework to Support Post-Surgical Discharge Monitoring

PubMed Central

Blansit, Kevin; Marmor, Rebecca; Zhao, Beiqun; Tien, Dan

2017-01-01

Unplanned surgical readmissions pose a challenging problem for the American healthcare system. We propose to combine consumer electronic voice recognition technology with the FHIR standard to create a post-surgical discharge monitoring app to identify and alert physicians to a patient’s deteriorating status. PMID:29854267

Attracting Preservice Teachers to Remote Locations

ERIC Educational Resources Information Center

Young, Kenneth D.; Grainger, Peter; James, Dennis

2018-01-01

Teaching in rural/remote regions poses many challenges to teachers and is identified as a priority research area by the state government. Despite initiatives by the Queensland state government and university providers to solve the issue through various incentives designed to attract teachers, the problem remains significant. This research…

Pre-Service Teachers' Free and Structured Mathematical Problem Posing

ERIC Educational Resources Information Center

Silber, Steven; Cai, Jinfa

2017-01-01

This exploratory study examined how pre-service teachers (PSTs) pose mathematical problems for free and structured mathematical problem-posing conditions. It was hypothesized that PSTs would pose more complex mathematical problems under structured posing conditions, with increasing levels of complexity, than PSTs would pose under free posing…

Human pose tracking from monocular video by traversing an image motion mapped body pose manifold

NASA Astrophysics Data System (ADS)

Basu, Saurav; Poulin, Joshua; Acton, Scott T.

2010-01-01

Tracking human pose from monocular video sequences is a challenging problem due to the large number of independent parameters affecting image appearance and nonlinear relationships between generating parameters and the resultant images. Unlike the current practice of fitting interpolation functions to point correspondences between underlying pose parameters and image appearance, we exploit the relationship between pose parameters and image motion flow vectors in a physically meaningful way. Change in image appearance due to pose change is realized as navigating a low dimensional submanifold of the infinite dimensional Lie group of diffeomorphisms of the two dimensional sphere S2. For small changes in pose, image motion flow vectors lie on the tangent space of the submanifold. Any observed image motion flow vector field is decomposed into the basis motion vector flow fields on the tangent space and combination weights are used to update corresponding pose changes in the different dimensions of the pose parameter space. Image motion flow vectors are largely invariant to style changes in experiments with synthetic and real data where the subjects exhibit variation in appearance and clothing. The experiments demonstrate the robustness of our method (within +/-4° of ground truth) to style variance.

Hysteresis and Phase Transitions in a Lattice Regularization of an Ill-Posed Forward-Backward Diffusion Equation

NASA Astrophysics Data System (ADS)

Helmers, Michael; Herrmann, Michael

2018-03-01

We consider a lattice regularization for an ill-posed diffusion equation with a trilinear constitutive law and study the dynamics of phase interfaces in the parabolic scaling limit. Our main result guarantees for a certain class of single-interface initial data that the lattice solutions satisfy asymptotically a free boundary problem with a hysteretic Stefan condition. The key challenge in the proof is to control the microscopic fluctuations that are inevitably produced by the backward diffusion when a particle passes the spinodal region.

Data philanthropy and the design of the infraethics for information societies.

PubMed

Taddeo, Mariarosaria

2016-12-28

In mature information societies, sharing data is increasingly recognized as a crucial means to foster their development. However, competing tensions on data control and ownership, limited technical understanding, and the lack of an adequate governance framework pose serious challenges to attempts to share data among different actors. Data philanthropy, understood as the donation of data from both individuals and private companies, has been proposed as means to meet these challenges. While at first sight data philanthropy may seem an uncontroversial phenomenon, a closer analysis reveals a bewildering network of problems. In this article, I analyse the role of data philanthropy in contemporary societies and the moral problems that it yields. I argue that the solution to these problems rests on the understanding of the infraethical nature of data philanthropy and on the design of an ethical framework encompassing the right infraethics and the right ethics. This is a framework able to address the changes brought about by the information revolution and to harness the opportunities that these pose for the prosperity of current and future information societies.This article is part of the themed issue 'The ethical impact of data science'. © 2016 The Author(s).

Robust head pose estimation via supervised manifold learning.

PubMed

Wang, Chao; Song, Xubo

2014-05-01

Head poses can be automatically estimated using manifold learning algorithms, with the assumption that with the pose being the only variable, the face images should lie in a smooth and low-dimensional manifold. However, this estimation approach is challenging due to other appearance variations related to identity, head location in image, background clutter, facial expression, and illumination. To address the problem, we propose to incorporate supervised information (pose angles of training samples) into the process of manifold learning. The process has three stages: neighborhood construction, graph weight computation and projection learning. For the first two stages, we redefine inter-point distance for neighborhood construction as well as graph weight by constraining them with the pose angle information. For Stage 3, we present a supervised neighborhood-based linear feature transformation algorithm to keep the data points with similar pose angles close together but the data points with dissimilar pose angles far apart. The experimental results show that our method has higher estimation accuracy than the other state-of-art algorithms and is robust to identity and illumination variations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Creativity of Field-dependent and Field-independent Students in Posing Mathematical Problems

NASA Astrophysics Data System (ADS)

Azlina, N.; Amin, S. M.; Lukito, A.

2018-01-01

This study aims at describing the creativity of elementary school students with different cognitive styles in mathematical problem-posing. The posed problems were assessed based on three components of creativity, namely fluency, flexibility, and novelty. The free-type problem posing was used in this study. This study is a descriptive research with qualitative approach. Data collections were conducted through written task and task-based interviews. The subjects were two elementary students. One of them is Field Dependent (FD) and the other is Field Independent (FI) which were measured by GEFT (Group Embedded Figures Test). Further, the data were analyzed based on creativity components. The results show thatFD student’s posed problems have fulfilled the two components of creativity namely fluency, in which the subject posed at least 3 mathematical problems, and flexibility, in whichthe subject posed problems with at least 3 different categories/ideas. Meanwhile,FI student’s posed problems have fulfilled all three components of creativity, namely fluency, in which thesubject posed at least 3 mathematical problems, flexibility, in which thesubject posed problems with at least 3 different categories/ideas, and novelty, in which the subject posed problems that are purely the result of her own ideas and different from problems they have known.

Geometry Challenges

ERIC Educational Resources Information Center

Robinson, James

2012-01-01

What is it that makes learners "think"? What geometrical problem, simply posed, can switch on the thinking processes of students? The author describes one such starting point that worked in a real classroom with Year 9 students. A group of learners for whom "mathematics comes easy" experience being stuck, they learn to handle this unfamiliar…

The Center of the Web: Workforce Development Partnerships

ERIC Educational Resources Information Center

Fowler, Donna; Chernus, Kathy

2005-01-01

The dilemma is familiar: too few resources to meet too many demands. Common to many public institutions, this problem poses special challenges to those working in community colleges, adult education and literacy programs, and workforce development organizations. These organizations all serve people who are at an economic and educational…

Building Intercultural Citizenship through Education: A Human Rights Approach

ERIC Educational Resources Information Center

Stavenhagen, Rodolfo

2008-01-01

This article analyses the challenges posed by traditional ethnic and linguistic minorities in multicultural states and more specifically the problems faced by indigenous peoples and communities. Their educational and cultural needs and demands are increasingly being framed in the language of human rights, based on the expanding international legal…

Managing Diversity in Education: Languages, Policies, Pedagogies

ERIC Educational Resources Information Center

Little, David, Ed.; Leung, Constant, Ed.; Van Avermaet, Piet

2013-01-01

Diversity--social, cultural, linguistic and ethnic--poses a challenge to all educational systems. Some authorities, schools and teachers look upon it as a problem, an obstacle to the achievement of national educational goals, while for others it offers new opportunities. Successive PISA reports have laid bare the relative lack of success in…

Planning Questions and Persevering in the Practices

ERIC Educational Resources Information Center

Gurl, Theresa J.; Fox, Ryan; Dabovic, Nikolina; Leavitt, Arielle Eager

2016-01-01

The implementation of the Common Core's Standards for Mathematical Practice can pose a challenge to all teachers of mathematics but especially to preservice teachers. These standards require teaching in a way that often differs from what preservice teachers have experienced as learners. Standard 1--"Make sense of problems and persevere in…

Family Stress and Coping for Mexican Origin Adolescents

ERIC Educational Resources Information Center

Liu, Freda F.; Gonzales, Nancy A.; Fernandez, Aida Cristina; Millsap, Roger E.; Dumka, Larry E.

2011-01-01

Family-related stressors pose special challenges for adolescents of Mexican origin, given traditional cultural norms that compel youths to get involved with family problems despite their limited ability to effect change. The current study examines the prospective effects of coping strategies (i.e., active, distraction, avoidance, support-seeking,…

Rank and Sparsity in Language Processing

ERIC Educational Resources Information Center

Hutchinson, Brian

2013-01-01

Language modeling is one of many problems in language processing that have to grapple with naturally high ambient dimensions. Even in large datasets, the number of unseen sequences is overwhelmingly larger than the number of observed ones, posing clear challenges for estimation. Although existing methods for building smooth language models tend to…

Skill Levels of Prospective Physics Teachers on Problem Posing

ERIC Educational Resources Information Center

Cildir, Sema; Sezen, Nazan

2011-01-01

Problem posing is one of the topics which the educators thoroughly accentuate. Problem posing skill is defined as an introvert activity of a student's learning. In this study, skill levels of prospective physics teachers on problem posing were determined and their views on problem posing were evaluated. To this end, prospective teachers were given…

Determining the Performances of Pre-Service Primary School Teachers in Problem Posing Situations

ERIC Educational Resources Information Center

Kilic, Cigdem

2013-01-01

This study examined the problem posing strategies of pre-service primary school teachers in different problem posing situations (PPSs) and analysed the issues they encounter while posing problems. A problem posing task consisting of six PPSs (two free, two structured, and two semi-structured situations) was delivered to 40 participants.…

Integrating security in multiple, remote, and diverse facilities: how major health systems are meeting today's and tomorrow's technological and organizational challenges.

PubMed

1996-11-01

As the trend to mergers and diversification of healthcare facilities grows, so too does the challenge to security directors to effectively and efficiently protect not only acute care, emergency, and outpatient facilities, but physician office buildings, parking garages, long-term-care units, medical schools, technical service units, and even health clubs. Besides the different security and communications problems posed by each type of facility, the problem of distance between facilities and their geographic location must also be met. In this report, we'll update you on the approaches being taken by security and planning executives at three leading health systems and how they are dealing with current and future problems.

Reinforcement learning in scheduling

NASA Technical Reports Server (NTRS)

Dietterich, Tom G.; Ok, Dokyeong; Zhang, Wei; Tadepalli, Prasad

1994-01-01

The goal of this research is to apply reinforcement learning methods to real-world problems like scheduling. In this preliminary paper, we show that learning to solve scheduling problems such as the Space Shuttle Payload Processing and the Automatic Guided Vehicle (AGV) scheduling can be usefully studied in the reinforcement learning framework. We discuss some of the special challenges posed by the scheduling domain to these methods and propose some possible solutions we plan to implement.

Blinded evaluation of farnesoid X receptor (FXR) ligands binding using molecular docking and free energy calculations

NASA Astrophysics Data System (ADS)

Selwa, Edithe; Elisée, Eddy; Zavala, Agustin; Iorga, Bogdan I.

2018-01-01

Our participation to the D3R Grand Challenge 2 involved a protocol in two steps, with an initial analysis of the available structural data from the PDB allowing the selection of the most appropriate combination of docking software and scoring function. Subsequent docking calculations showed that the pose prediction can be carried out with a certain precision, but this is dependent on the specific nature of the ligands. The correct ranking of docking poses is still a problem and cannot be successful in the absence of good pose predictions. Our free energy calculations on two different subsets provided contrasted results, which might have the origin in non-optimal force field parameters associated with the sulfonamide chemical moiety.

Rethinking the globalisation of problem-based learning: how culture challenges self-directed learning.

PubMed

Frambach, Janneke M; Driessen, Erik W; Chan, Li-Chong; van der Vleuten, Cees P M

2012-08-01

Medical schools worldwide are increasingly switching to student-centred methods such as problem-based learning (PBL) to foster lifelong self-directed learning (SDL). The cross-cultural applicability of these methods has been questioned because of their Western origins and because education contexts and learning approaches differ across cultures. This study evaluated PBL's cross-cultural applicability by investigating how it is applied in three medical schools in regions with different cultures in, respectively, East Asia, the Middle East and Western Europe. Specifically, it investigated how students' cultural backgrounds impact on SDL in PBL and how this impact affects students. A qualitative, cross-cultural, comparative case study was conducted in three medical schools. Data were collected through 88 semi-structured, in-depth interviews with Year 1 and 3 students, tutors and key persons involved in PBL, 32 observations of Year 1 and 3 PBL tutorials, document analysis, and contextual information. The data were thematically analysed using the template analysis method. Comparisons were made among the three medical schools and between Year 1 and 3 students across and within the schools. The cultural factors of uncertainty and tradition posed a challenge to Middle Eastern students' SDL. Hierarchy posed a challenge to Asian students and achievement impacted on both sets of non-Western students. These factors were less applicable to European students, although the latter did experience some challenges. Several contextual factors inhibited or enhanced SDL across the cases. As students grew used to PBL, SDL skills increased across the cases, albeit to different degrees. Although cultural factors can pose a challenge to the application of PBL in non-Western settings, it appears that PBL can be applied in different cultural contexts. However, its globalisation does not postulate uniform processes and outcomes, and culturally sensitive alternatives might be developed. © Blackwell Publishing Ltd 2012.

Embedding Game-Based Problem-Solving Phase into Problem-Posing System for Mathematics Learning

ERIC Educational Resources Information Center

Chang, Kuo-En; Wu, Lin-Jung; Weng, Sheng-En; Sung, Yao-Ting

2012-01-01

A problem-posing system is developed with four phases including posing problem, planning, solving problem, and looking back, in which the "solving problem" phase is implemented by game-scenarios. The system supports elementary students in the process of problem-posing, allowing them to fully engage in mathematical activities. In total, 92 fifth…

Characteristics of Problem Posing of Grade 9 Students on Geometric Tasks

ERIC Educational Resources Information Center

Chua, Puay Huat; Wong, Khoon Yoong

2012-01-01

This is an exploratory study into the individual problem-posing characteristics of 480 Grade 9 Singapore students who were novice problem posers working on two geometric tasks. The students were asked to pose a problem for their friends to solve. Analyses of solvable posed problems were based on the problem type, problem information, solution type…

Pose estimation of industrial objects towards robot operation

NASA Astrophysics Data System (ADS)

Niu, Jie; Zhou, Fuqiang; Tan, Haishu; Cao, Yu

2017-10-01

With the advantages of wide range, non-contact and high flexibility, the visual estimation technology of target pose has been widely applied in modern industry, robot guidance and other engineering practices. However, due to the influence of complicated industrial environment, outside interference factors, lack of object characteristics, restrictions of camera and other limitations, the visual estimation technology of target pose is still faced with many challenges. Focusing on the above problems, a pose estimation method of the industrial objects is developed based on 3D models of targets. By matching the extracted shape characteristics of objects with the priori 3D model database of targets, the method realizes the recognition of target. Thus a pose estimation of objects can be determined based on the monocular vision measuring model. The experimental results show that this method can be implemented to estimate the position of rigid objects based on poor images information, and provides guiding basis for the operation of the industrial robot.

Multidisciplinary Optimization of a Transport Aircraft Wing using Particle Swarm Optimization

NASA Technical Reports Server (NTRS)

Sobieszczanski-Sobieski, Jaroslaw; Venter, Gerhard

2002-01-01

The purpose of this paper is to demonstrate the application of particle swarm optimization to a realistic multidisciplinary optimization test problem. The paper's new contributions to multidisciplinary optimization is the application of a new algorithm for dealing with the unique challenges associated with multidisciplinary optimization problems, and recommendations as to the utility of the algorithm in future multidisciplinary optimization applications. The selected example is a bi-level optimization problem that demonstrates severe numerical noise and has a combination of continuous and truly discrete design variables. The use of traditional gradient-based optimization algorithms is thus not practical. The numerical results presented indicate that the particle swarm optimization algorithm is able to reliably find the optimum design for the problem presented here. The algorithm is capable of dealing with the unique challenges posed by multidisciplinary optimization as well as the numerical noise and truly discrete variables present in the current example problem.

Teacher Behavioral Practices: Relations to Student Risk Behaviors, Learning Barriers, and School Climate

ERIC Educational Resources Information Center

Martinez, Andrew; Mcmahon, Susan D.; Coker, Crystal; Keys, Christopher B.

2016-01-01

Student behavioral problems pose a myriad of challenges for schools. In this study, we examine the relations among teacher and school-level constructs (i.e., teacher collaboration, supervision/discipline, instructional management), and student-related outcomes (i.e., high-risk behaviors, barriers to learning, student social-behavioral climate).…

Examining the Dynamics of Managing Information Systems Development Projects: A Control Loss Perspective

ERIC Educational Resources Information Center

Narayanaswamy, Ravi

2009-01-01

The failure rate of information systems development (ISD) projects continues to pose a big challenge for organizations. The success rate of ISD projects is less then forty percent. Factors such as disagreements and miscommunications among project manager and team members, poor monitoring and intermediary problems contribute to project failure.…

EFL Learner's Awareness of Stress-Moving vs. Neutral Suffixes

ERIC Educational Resources Information Center

Shemshadsara, Zahra Ghorbani

2011-01-01

Mastering pronunciation in EFL context, where direct access to native speaker is scarce, is a highly challenging objective for many language students in Iran. Stress as a suprasegmental feature, more specifically, poses its own problems, specially when suffixes are added to words. There are different types of suffixes, two of which are neutral…

The Tree in Pythagoras' Garden

ERIC Educational Resources Information Center

Mack, John; Czernezkyj, Vic

2010-01-01

This geometrical account of primitive Pythagorean triples was stimulated by a remark of Douglas Rogers on a recent paper by Roger Alperin (Alperin, 2005). Rogers, in commenting on this paper, noted that Fermat in the 17th century had posed a challenge problem on Pythagorean triples that suggested he knew how to construct a sequence of them,…

Little Kids, Big Worries: Stress-Busting Tips for Early Childhood Classrooms

ERIC Educational Resources Information Center

Honig, Alice Sterling

2010-01-01

Research shows that stress in the crucial early years of a child's life can pose dramatic, lasting challenges to development, learning, and behavior. This is the practical book early childhood professionals need to recognize stress in young children--and intervene with proven relief strategies before pressures turn into big problems. Developed by…

Curriculum Change Management and Workload

ERIC Educational Resources Information Center

Alkahtani, Aishah

2017-01-01

This study examines the ways in which Saudi teachers have responded or are responding to the challenges posed by a new curriculum. It also deals with issues relating to workload demands which affect teachers' performance when they apply a new curriculum in a Saudi Arabian secondary school. In addition, problems such as scheduling and sharing space…

Task Design for L2 Oral Practice in Audioblogs

ERIC Educational Resources Information Center

Appel, Christine; Borges, Federico

2012-01-01

The development of oral skills poses a challenge in language teaching whether this takes place face-to-face, through distance education or in blended learning contexts. Two main problems arise: first of all students don't have enough opportunity to use their target language orally, and secondly, students oral performance is mostly unrecorded and…

Commentary: Definitely More than Measurement Error--But How Should We Understand and Deal with Informant Discrepancies?

ERIC Educational Resources Information Center

Achenbach, Thomas M.

2011-01-01

The special section articles demonstrate the importance of informant discrepancies. They also illustrate challenges posed by discrepancies, plus opportunities for advancing research and practice. This commentary addresses these cross-cutting issues: (a) Discrepancies affect many kinds of assessment besides ratings of children's problems. (b)…

Coping with AIDS: Psychological and Social Considerations in Helping People with HTLV-III Infection.

ERIC Educational Resources Information Center

Runck, Bette

This booklet was written to familiarize health and mental health professionals and paraprofessionals with the psychological and social problems associated with acquired immune deficiency syndrome (AIDS). It briefly reviews the realities of AIDS and describes the challenge that AIDS poses for health care professionals. A section on neuropsychiatric…

The Problem with Women? Challenges Posed by Gender for Career Guidance Practice

ERIC Educational Resources Information Center

Bimrose, Jenny; Watson, Mark; McMahon, Mary; Haasler, Simone; Tomassini, Massimo; Suzanne, Pamela A.

2014-01-01

Institutionalised discrimination continues to perpetuate deep rooted social divisions, with gender inequality persisting as a pervasive feature of labour markets across the world. Despite the depth and breadth of gender inequality, there is limited acknowledgement in career theory that the career support needs of women are distinctive. A…

Problem Posing with the Multiplication Table

ERIC Educational Resources Information Center

Dickman, Benjamin

2014-01-01

Mathematical problem posing is an important skill for teachers of mathematics, and relates readily to mathematical creativity. This article gives a bit of background information on mathematical problem posing, lists further references to connect problem posing and creativity, and then provides 20 problems based on the multiplication table to be…

Investigation of Problem-Solving and Problem-Posing Abilities of Seventh-Grade Students

ERIC Educational Resources Information Center

Arikan, Elif Esra; Ünal, Hasan

2015-01-01

This study aims to examine the effect of multiple problem-solving skills on the problem-posing abilities of gifted and non-gifted students and to assess whether the possession of such skills can predict giftedness or affect problem-posing abilities. Participants' metaphorical images of problem posing were also explored. Participants were 20 gifted…

Sustainable development and environmental protection: A perspective on current trends and future options for universities

NASA Astrophysics Data System (ADS)

Lemons, John

1995-03-01

Problems of sustainable development and environmental protection pose a challenge to humanity unprecedented in scope and complexity. Whether and how the problems are resolved have significant implications for human and ecological well-being. In this paper, I discuss briefly recent international recommendations to promote sustainable development and environmental protection. I then offer a perspective on the roles and prospects of the university in promoting sustainable development and environmental protection.

The Space Apps Challenge: Using Open Innovation Competitions to Engage The Public in the Scientific Process

NASA Astrophysics Data System (ADS)

Gupta, S. S.

2016-12-01

NASA's Space Apps Challenge encourages innovation, creativity and collaborative problem solving by gathering coders, builders, artists, designers, and storytellers in a 48-hour hackathon. Open Innovation competitions such as the Space Apps Challenge bring the scientific world to members of the public, regardless of age, experience, credentials, or expertise. In the past five years, this model of public engagement has been widely employed by government, nonprofit and academic institutions, allowing the building of partnerships between the scientific community and the individuals and communities they serve. Furthermore, advances in technology and challenge models have lowered the barriers and costs to scientific collaboration with and for the public. NASA's Space Apps Challenge, structured as a competition seeking solutions from the public to posed problems, brings together teams and forges collaborations between individuals and groups who would otherwise have never worked together for a short but high intensity problem solving session, Space Apps has has created a pathway to public engagement and innovation that is often faster, cheaper, and more impactful than traditional approaches.

Some Reflections on Problem Posing: A Conversation with Marion Walter

ERIC Educational Resources Information Center

Baxter, Juliet A.

2005-01-01

Marion Walter, an internationally acclaimed mathematics educator discusses about problem posing, focusing on both the merits of problem posing and techniques to encourage problem posing. She believes that playful attitude toward problem variables is an essential part of an inquiring mind and the more opportunities that learners have, to change a…

Investigation of learning environment for arithmetic word problems by problem posing as sentence integration in Indonesian language

NASA Astrophysics Data System (ADS)

Hasanah, N.; Hayashi, Y.; Hirashima, T.

2017-02-01

Arithmetic word problems remain one of the most difficult area of teaching mathematics. Learning by problem posing has been suggested as an effective way to improve students’ understanding. However, the practice in usual classroom is difficult due to extra time needed for assessment and giving feedback to students’ posed problems. To address this issue, we have developed a tablet PC software named Monsakun for learning by posing arithmetic word problems based on Triplet Structure Model. It uses the mechanism of sentence-integration, an efficient implementation of problem-posing that enables agent-assessment of posed problems. The learning environment has been used in actual Japanese elementary school classrooms and the effectiveness has been confirmed in previous researches. In this study, ten Indonesian elementary school students living in Japan participated in a learning session of problem posing using Monsakun in Indonesian language. We analyzed their learning activities and show that students were able to interact with the structure of simple word problem using this learning environment. The results of data analysis and questionnaire suggested that the use of Monsakun provides a way of creating an interactive and fun environment for learning by problem posing for Indonesian elementary school students.

Pose tracking for augmented reality applications in outdoor archaeological sites

NASA Astrophysics Data System (ADS)

Younes, Georges; Asmar, Daniel; Elhajj, Imad; Al-Harithy, Howayda

2017-01-01

In recent years, agencies around the world have invested huge amounts of effort toward digitizing many aspects of the world's cultural heritage. Of particular importance is the digitization of outdoor archaeological sites. In the spirit of valorization of this digital information, many groups have developed virtual or augmented reality (AR) computer applications themed around a particular archaeological object. The problem of pose tracking in outdoor AR applications is addressed. Different positional systems are analyzed, resulting in the selection of a monocular camera-based user tracker. The limitations that challenge this technique from map generation, scale, anchoring, to lighting conditions are analyzed and systematically addressed. Finally, as a case study, our pose tracking system is implemented within an AR experience in the Byblos Roman theater in Lebanon.

The 2014 Sandia Verification and Validation Challenge: Problem statement

DOE PAGES

Hu, Kenneth; Orient, George

2016-01-18

This paper presents a case study in utilizing information from experiments, models, and verification and validation (V&V) to support a decision. It consists of a simple system with data and models provided, plus a safety requirement to assess. The goal is to pose a problem that is flexible enough to allow challengers to demonstrate a variety of approaches, but constrained enough to focus attention on a theme. This was accomplished by providing a good deal of background information in addition to the data, models, and code, but directing the participants' activities with specific deliverables. In this challenge, the theme ismore » how to gather and present evidence about the quality of model predictions, in order to support a decision. This case study formed the basis of the 2014 Sandia V&V Challenge Workshop and this resulting special edition of the ASME Journal of Verification, Validation, and Uncertainty Quantification.« less

e-Health promises and challenges: some ethical considerations.

PubMed

Kluge, Eike-Henner W

2011-01-01

eHealth is a cost-effective and efficient way of providing health care to patients who would otherwise be excluded or underserviced. However, eHealth also presents a series of ethical and legal challenges which, if not met before its implementation, can undermine its success. Among other things, privacy, consent and liability are implicated, as are changes in the health care professional-patient relationship and in the role of health informatics professionals. Legacy systems and interoperability present further challenges, and outsourcing may pose special problems. This paper highlights some of these issues and outlines their implications.

Tackling U.S. energy challenges and opportunities: preliminary policy recommendations for enhancing energy innovation in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anadon, Laura Diaz; Gallagher, Kelly Sims; Bunn, Matthew

2009-02-18

The report offers preliminary recommendations for near-term actions to strengthen the U.S. effort to develop and deploy advanced energy technologies. The report comes as the Obama Administration and the 111th U.S. Congress face enormous challenges and opportunities in tackling the pressing security, economic, and environmental problems posed by the energy sector. Improving the technologies of energy supply and end-use is a prerequisite for surmounting these challenges in a timely and cost-effective way, and this report elaborates on how policy can support develop of these important energy technologies.

WFIRST: Microlensing Analysis Data Challenge

NASA Astrophysics Data System (ADS)

Street, Rachel; WFIRST Microlensing Science Investigation Team

2018-01-01

WFIRST will produce thousands of high cadence, high photometric precision lightcurves of microlensing events, from which a wealth of planetary and stellar systems will be discovered. However, the analysis of such lightcurves has historically been very time consuming and expensive in both labor and computing facilities. This poses a potential bottleneck to deriving the full science potential of the WFIRST mission. To address this problem, the WFIRST Microlensing Science Investigation Team designing a series of data challenges to stimulate research to address outstanding problems of microlensing analysis. These range from the classification and modeling of triple lens events to methods to efficiently yet thoroughly search a high-dimensional parameter space for the best fitting models.

The problem of ecological scaling in spatially complex, nonequilibrium ecological systems [chapter 3

Treesearch

Samuel A. Cushman; Jeremy Littell; Kevin McGarigal

2010-01-01

In the previous chapter we reviewed the challenges posed by spatial complexity and temporal disequilibrium to efforts to understand and predict the structure and dynamics of ecological systems. The central theme was that spatial variability in the environment and population processes fundamentally alters the interactions between species and their environments, largely...

Motivating Computer Engineering Freshmen through Mathematical and Logical Puzzles

ERIC Educational Resources Information Center

Parhami, B.

2009-01-01

As in many other fields of science and technology, college students in computer engineering do not come into full contact with the key ideas and challenges of their chosen discipline until the third year of their studies. This situation poses a problem in terms of keeping the students motivated as they labor through their foundational, basic…

Paradigms and problems: The practice of social science in natural resource management

Treesearch

Michael E. Patterson; Daniel R. Williams

1998-01-01

Increasingly, natural resource management is seeing calls for new paradigms. These calls pose challenges that have implications not only for planning and management, but also for the practice of science. As a consequence, the profession needs to deepen its understanding of the nature of science by exploring recent advances in the philosophy of science....

When There Isn't a Right Answer: Interpretation and Reasoning, Key Skills for Twenty-First Century Geoscience

ERIC Educational Resources Information Center

Bond, Clare Elizabeth; Philo, Chris; Shipton, Zoe Kai

2011-01-01

A key challenge in university geoscience teaching is to give students the skills to cope with uncertainty. Professional geoscientists can rarely be certain of the "right answer" to problems posed by most geological datasets, and reasoning through this uncertainty, being intelligently flexible in interpreting data which are limited in resolution…

Wholistic orthopedics: Is this the right way to treat geriatric orthopedic patients?

PubMed Central

Ebnezar, John; Bali, Yogita; John, Rakesh

2017-01-01

Geriatric orthopedic problems poses different challenges in their management. Conventional treatment methods like drugs, physiotherapy and surgeries are inadequate. A Geriatric orthopedic patient suffers as a whole and not in isolation. This article highlights the importance of managing geriatric orthopedic patients as a whole and outlines the various steps of wholistic management. PMID:28149067

Buildings as Artifacts: What Are Buildings in World History Telling Us?

ERIC Educational Resources Information Center

O'Brien, Joe; Peavey, Scott; Fuller, Molly

2016-01-01

Learning about people from long ago and far away poses a challenge for students because such people seem so distant and different. The lack of easily comprehensible text-based primary sources compounds this problem. Using a built environment as a primary source makes people from the distant past more accessible, concrete and exciting. Broadly…

Differentiating Instruction Using a Virtual Environment: A Study of Mathematical Problem Posing among Gifted and Talented Learners

ERIC Educational Resources Information Center

Manuel, Dominic; Freiman, Viktor

2017-01-01

Meeting the needs of mathematically gifted and talented students is a challenge for educators. To support teachers of mathematically gifted and talented students to find appropriate solutions, several innovative projects were conducted in schools using funds provided by the New Brunswick, Canada, Department of Education. This article presents one…

Internet Color Imaging

DTIC Science & Technology

2000-07-01

UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADPO1 1348 TITLE: Internet Color Imaging DISTRIBUTION: Approved for public...Paper Internet Color Imaging Hsien-Che Lee Imaging Science and Technology Laboratory Eastman Kodak Company, Rochester, New York 14650-1816 USA...ABSTRACT The sharing and exchange of color images over the Internet pose very challenging problems to color science and technology . Emerging color standards

Wholistic orthopedics: Is this the right way to treat geriatric orthopedic patients?

PubMed

Ebnezar, John; Bali, Yogita; John, Rakesh

2017-01-01

Geriatric orthopedic problems poses different challenges in their management. Conventional treatment methods like drugs, physiotherapy and surgeries are inadequate. A Geriatric orthopedic patient suffers as a whole and not in isolation. This article highlights the importance of managing geriatric orthopedic patients as a whole and outlines the various steps of wholistic management.

Challenging the Wikipedia Mentality: Encouraging Original Inquiry through Freire's Problem-Posing Method

ERIC Educational Resources Information Center

Deys, Kellie L.; Deys, James L.

2016-01-01

For most millennials, information has always been a couple of quick taps away. Sites have seemingly always existed to provide them with "the answer." Instructors must recognize that not only are they teaching material from their disciplines, but also they are trying to teach the skill and value of critical inquiry. Adopting a Freirean…

Replacement of the valvular prosthesis in a patient with a Bentall procedure.

PubMed

Panos, A L; Teoh, K T; Wilson, J K; Salerno, T A

1992-09-01

Patients who have had the Bentall-DeBono procedure using a composite conduit with a tissue valvular prosthesis pose a great challenge when problems develop with the tissue prosthesis. We herein report the surgical management of one such case, in which the valvular prosthesis was removed and replaced without replacement of the conduit.

Learning Disabilities and Career Development. Practice Application Brief No. 20.

ERIC Educational Resources Information Center

Kerka, Sandra

The lifelong process of career development poses special challenges for people with learning disabilities (LD). Literature on employment issues for adults with LD frames on-the-job problems in terms of individual deficits or recasts the issues as a function of the significant societal barriers faced by those who do not fit the norm. Research on…

Ethics, Ricoeur And Philosophy: Ethical Teacher Workshops

ERIC Educational Resources Information Center

Scott-Baumann, Alison

2006-01-01

This work is about the ethics of education, and about philosophy as a discipline that can help us to help children look at ethics afresh. The study and practice of ethics is about morals and uncertainties and, as such, poses problems for the research community. The philosopher Ricoeur challenges research as only one way to find meaning in the…

Opportunities, Challenges and Questions: Continual Assessment in Year 9

ERIC Educational Resources Information Center

Cain, Karl; Neal, Christina

2004-01-01

Our means of assessment might pose a problem. History teachers regularly set specific targets, with implicit or explicit reference to National Curriculum Levels, which are designed to move our pupils on and make them better historians. How, though, are we to prevent them from achieving their targets in a rather mechanistic way, ticking the boxes…

Prioritizing Threats to Patient Safety in Rural Primary Care

ERIC Educational Resources Information Center

Singh, Ranjit; Singh, Ashok; Servoss, Timothy J.; Singh, Gurdev

2007-01-01

Context: Rural primary care is a complex environment in which multiple patient safety challenges can arise. To make progress in improving safety with limited resources, each practice needs to identify those safety problems that pose the greatest threat to patients and focus efforts on these. Purpose: To describe and field-test a novel approach to…

An Analysis of Middle School SATB and SAB Choral Sight Reading Contest Literature

ERIC Educational Resources Information Center

Poché-Rodriguez, Kelley

2013-01-01

Between 2006 and 2012, 9% of all middle school choral entries in the Texas University Interscholastic League (UIL) Concert and Sight Reading Contest consisted of mixed choirs (N = 842) (Texas UIL, 2012a). Middle school mixed choirs pose unique pedagogical problems for directors. One such challenge lies in the determination of whether to perform…

Serving the Information Needs of the International and Minority Students at the Small College Library: A Librarian's View.

ERIC Educational Resources Information Center

Burhans, Skip

International and minority students often pose additional challenges due to cultural, linguistic, or socio-economic differences with the mostly white, middle class, highly educated (and predominantly female) public service librarians with whom they come into contact. Such differences can range from minor speech/articulation problems to major…

Test Equity for Individuals Who Are Deaf or Hard of Hearing. PEPNet Test Equity Summit

ERIC Educational Resources Information Center

PEPNet-West, 2010

2010-01-01

This paper presents the highlights of the 2008 Test Equity Summit held in Bloomfield, Colorado last August 6-8, 2008. The 2008 Test Equity Summit convened by the Postsecondary Education Programs Network (PEPNet) identified and examined problems, challenges, and issues that academic and psychoeducational tests pose for individuals who are deaf or…

Getting ahead of the wildfire problem: Quantifying and mapping management challenges and opportunities

Treesearch

Christopher D. O' Connor; Matthew P. Thompson; Francisco Rodriguez y Silva

2016-01-01

Wildfire is a global phenomenon that plays a vital role in regulating and maintaining many natural and human-influenced ecosystems but that also poses considerable risks to human populations and infrastructure. Fire managers are charged with balancing the short-term protection of human assets sensitive to fire exposure against the potential long-term benefits...

Strengthening Causal Estimates for Links Between Spanking and Children's Externalizing Behavior Problems.

PubMed

Gershoff, Elizabeth T; Sattler, Kierra M P; Ansari, Arya

2018-01-01

Establishing causal links when experiments are not feasible is an important challenge for psychology researchers. The question of whether parents' spanking causes children's externalizing behavior problems poses such a challenge because randomized experiments of spanking are unethical, and correlational studies cannot rule out potential selection factors. This study used propensity score matching based on the lifetime prevalence and recent incidence of spanking in a large and nationally representative sample ( N = 12,112) as well as lagged dependent variables to get as close to causal estimates outside an experiment as possible. Whether children were spanked at the age of 5 years predicted increases in externalizing behavior problems by ages 6 and 8, even after the groups based on spanking prevalence or incidence were matched on a range of sociodemographic, family, and cultural characteristics and children's initial behavior problems. These statistically rigorous methods yield the conclusion that spanking predicts a deterioration of children's externalizing behavior over time.

Problem Posing as a Pedagogical Strategy: A Teacher's Perspective

ERIC Educational Resources Information Center

Staebler-Wiseman, Heidi A.

2011-01-01

Student problem posing has been advocated for mathematics instruction, and it has been suggested that problem posing can be used to develop students' mathematical content knowledge. But, problem posing has rarely been utilized in university-level mathematics courses. The goal of this teacher-as-researcher study was to develop and investigate…

Students’ Creativity: Problem Posing in Structured Situation

NASA Astrophysics Data System (ADS)

Amalina, I. K.; Amirudin, M.; Budiarto, M. T.

2018-01-01

This is a qualitative research concerning on students’ creativity on problem posing task. The study aimed at describing the students’ creative thinking ability to pose the mathematics problem in structured situations with varied condition of given problems. In order to find out the students’ creative thinking ability, an analysis of mathematics problem posing test based on fluency, novelty, and flexibility and interview was applied for categorizing students’ responses on that task. The data analysis used the quality of problem posing and categorized in 4 level of creativity. The results revealed from 29 secondary students grade 8, a student in CTL (Creative Thinking Level) 1 met the fluency. A student in CTL 2 met the novelty, while a student in CTL 3 met both fluency and novelty and no one in CTL 4. These results are affected by students’ mathematical experience. The findings of this study highlight that student’s problem posing creativity are dependent on their experience in mathematics learning and from the point of view of which students start to pose problem.

A validated non-linear Kelvin-Helmholtz benchmark for numerical hydrodynamics

NASA Astrophysics Data System (ADS)

Lecoanet, D.; McCourt, M.; Quataert, E.; Burns, K. J.; Vasil, G. M.; Oishi, J. S.; Brown, B. P.; Stone, J. M.; O'Leary, R. M.

2016-02-01

The non-linear evolution of the Kelvin-Helmholtz instability is a popular test for code verification. To date, most Kelvin-Helmholtz problems discussed in the literature are ill-posed: they do not converge to any single solution with increasing resolution. This precludes comparisons among different codes and severely limits the utility of the Kelvin-Helmholtz instability as a test problem. The lack of a reference solution has led various authors to assert the accuracy of their simulations based on ad hoc proxies, e.g. the existence of small-scale structures. This paper proposes well-posed two-dimensional Kelvin-Helmholtz problems with smooth initial conditions and explicit diffusion. We show that in many cases numerical errors/noise can seed spurious small-scale structure in Kelvin-Helmholtz problems. We demonstrate convergence to a reference solution using both ATHENA, a Godunov code, and DEDALUS, a pseudo-spectral code. Problems with constant initial density throughout the domain are relatively straightforward for both codes. However, problems with an initial density jump (which are the norm in astrophysical systems) exhibit rich behaviour and are more computationally challenging. In the latter case, ATHENA simulations are prone to an instability of the inner rolled-up vortex; this instability is seeded by grid-scale errors introduced by the algorithm, and disappears as resolution increases. Both ATHENA and DEDALUS exhibit late-time chaos. Inviscid simulations are riddled with extremely vigorous secondary instabilities which induce more mixing than simulations with explicit diffusion. Our results highlight the importance of running well-posed test problems with demonstrated convergence to a reference solution. To facilitate future comparisons, we include as supplementary material the resolved, converged solutions to the Kelvin-Helmholtz problems in this paper in machine-readable form.

Democracy Through Learner-Centered Education: a Turkish Perspective

NASA Astrophysics Data System (ADS)

Yilmaz, Kaya

2009-01-01

Aimed at documenting the problems and constraints confronting learner-centered instruction in Turkey, this article first explains the link between democracy and education and the role of learner-centered instruction in realizing democratic ends. By drawing on John Dewey's ideas and Turkish scholars' perspectives on Turkish education, the article then presents the problems and constraints that pose threats to the implementation of learner-centered instruction in Turkey. The author also explains the problems within the Turkish educational system and teacher education programmes, and the challenges that in-service teachers and students may experience with learner-centered instruction.

Reliability and availability modeling of coupled communication networks - A simplified modeling approach

NASA Technical Reports Server (NTRS)

Shooman, Martin L.; Cortes, Eladio R.

1991-01-01

The network-complexity of LANs and of LANs that are interconnected by bridges and routers poses a challenging reliability-modeling problem. The present effort toward these problems' solution attempts to simplify them by reducing their number of states through truncation and state merging, as suggested by Shooman and Laemmel (1990). Through the use of state merging, it becomes possible to reduce the Bateman-Cortes 161 state model to a two state model with a closed-form solution. In the case of coupled networks, a technique which allows for problem-decomposition must be used.

What does public health ethics tell (or not tell) us about intervening in non-communicable diseases?

PubMed

Upshur, Ross

2013-03-01

Obesity has been described as pandemic and a public health crisis. It has been argued that concerted research efforts are needed to enhance our understanding and develop effective interventions for the complex and multiple dimensions of the health challenges posed by obesity. This would provide a secure evidence base in order to justify clinical interventions and public policy. This paper critically examines these claims through the examination of models of public health and public health ethics. I argue that the concept of an effective public health intervention is unclear and underdeveloped and, as a consequence, normative frameworks reliant on meeting the effectiveness criterion may miss morally salient dimensions of the problems. I conclude by arguing for the need to consider both an ecological model of public health and inclusion of a critical public health ethics perspective for an adequate account of the public health challenges posed by obesity.

Assessing Students' Mathematical Problem Posing

ERIC Educational Resources Information Center

Silver, Edward A.; Cai, Jinfa

2005-01-01

Specific examples are used to discuss assessment, an integral part of mathematics instruction, with problem posing and assessment of problem posing. General assessment criteria are suggested to evaluate student-generated problems in terms of their quantity, originality, and complexity.

Preparing to understand and use science in the real world: interdisciplinary study concentrations at the Technical University of Darmstadt.

PubMed

Liebert, Wolfgang J

2013-12-01

In order to raise awareness of the ambiguous nature of scientific-technological progress, and of the challenging problems it raises, problems which are not easily addressed by courses in a single discipline and cannot be projected onto disciplinary curricula, Technical University of Darmstadt has established three interdisciplinary study concentrations: "Technology and International Development", "Environmental Sciences", and "Sustainable Shaping of Technology and Science". These three programmes seek to overcome the limitations of strictly disciplinary research and teaching by developing an integrated, problem-oriented approach. For example, one course considers fundamental nuclear dilemmas and uses role-playing techniques to address a controversy in the area of nuclear security. At the same time, incorporating interdisciplinary teaching into a university that is organized around mono- or multi-disciplinary faculties also poses a number of challenges. Recognition in disciplinary curricula, and appropriate organizational support and funding are examples of those challenges. It is expected that science and engineering students, empowered by such interdisciplinary study programmes, will be better prepared to act responsibly with regard to scientific and technological challenges.

A Bayesian Framework for Human Body Pose Tracking from Depth Image Sequences

PubMed Central

Zhu, Youding; Fujimura, Kikuo

2010-01-01

This paper addresses the problem of accurate and robust tracking of 3D human body pose from depth image sequences. Recovering the large number of degrees of freedom in human body movements from a depth image sequence is challenging due to the need to resolve the depth ambiguity caused by self-occlusions and the difficulty to recover from tracking failure. Human body poses could be estimated through model fitting using dense correspondences between depth data and an articulated human model (local optimization method). Although it usually achieves a high accuracy due to dense correspondences, it may fail to recover from tracking failure. Alternately, human pose may be reconstructed by detecting and tracking human body anatomical landmarks (key-points) based on low-level depth image analysis. While this method (key-point based method) is robust and recovers from tracking failure, its pose estimation accuracy depends solely on image-based localization accuracy of key-points. To address these limitations, we present a flexible Bayesian framework for integrating pose estimation results obtained by methods based on key-points and local optimization. Experimental results are shown and performance comparison is presented to demonstrate the effectiveness of the proposed approach. PMID:22399933

Performance of multiple docking and refinement methods in the pose prediction D3R prospective Grand Challenge 2016

NASA Astrophysics Data System (ADS)

Fradera, Xavier; Verras, Andreas; Hu, Yuan; Wang, Deping; Wang, Hongwu; Fells, James I.; Armacost, Kira A.; Crespo, Alejandro; Sherborne, Brad; Wang, Huijun; Peng, Zhengwei; Gao, Ying-Duo

2018-01-01

We describe the performance of multiple pose prediction methods for the D3R 2016 Grand Challenge. The pose prediction challenge includes 36 ligands, which represent 4 chemotypes and some miscellaneous structures against the FXR ligand binding domain. In this study we use a mix of fully automated methods as well as human-guided methods with considerations of both the challenge data and publicly available data. The methods include ensemble docking, colony entropy pose prediction, target selection by molecular similarity, molecular dynamics guided pose refinement, and pose selection by visual inspection. We evaluated the success of our predictions by method, chemotype, and relevance of publicly available data. For the overall data set, ensemble docking, visual inspection, and molecular dynamics guided pose prediction performed the best with overall mean RMSDs of 2.4, 2.2, and 2.2 Å respectively. For several individual challenge molecules, the best performing method is evaluated in light of that particular ligand. We also describe the protein, ligand, and public information data preparations that are typical of our binding mode prediction workflow.

Fundamentals of diffusion MRI physics.

PubMed

Kiselev, Valerij G

2017-03-01

Diffusion MRI is commonly considered the "engine" for probing the cellular structure of living biological tissues. The difficulty of this task is threefold. First, in structurally heterogeneous media, diffusion is related to structure in quite a complicated way. The challenge of finding diffusion metrics for a given structure is equivalent to other problems in physics that have been known for over a century. Second, in most cases the MRI signal is related to diffusion in an indirect way dependent on the measurement technique used. Third, finding the cellular structure given the MRI signal is an ill-posed inverse problem. This paper reviews well-established knowledge that forms the basis for responding to the first two challenges. The inverse problem is briefly discussed and the reader is warned about a number of pitfalls on the way. Copyright © 2017 John Wiley & Sons, Ltd.

Coupling of Large Amplitude Inversion with Other States

NASA Astrophysics Data System (ADS)

Pearson, John; Yu, Shanshan

2016-06-01

The coupling of a large amplitude motion with a small amplitude vibration remains one of the least well characterized problems in molecular physics. Molecular inversion poses a few unique and not intuitively obvious challenges to the large amplitude motion problem. In spite of several decades of theoretical work numerous challenges in calculation of transition frequencies and more importantly intensities persist. The most challenging aspect of this problem is that the inversion coordinate is a unique function of the overall vibrational state including both the large and small amplitude modes. As a result, the r-axis system and the meaning of the K-quantum number in the rotational basis set are unique to each vibrational state of large or small amplitude motion. This unfortunate reality has profound consequences to calculation of intensities and the coupling of nearly degenerate vibrational states. The case of NH3 inversion and inversion through a plane of symmetry in alcohols will be examined to find a general path forward.

Aerospace Measurements: Challenges and Opportunities

NASA Technical Reports Server (NTRS)

Conway, Bruce A.

1992-01-01

New aerospace research initiatives offer both challenges and opportunities to rapidly-emerging electronics and electro-optics technology. Defining and implementing appropriate measurement technology development programs in response to the aeronautical ground facility research and testing needs of the new initiatives poses some particularly important problems. This paper discusses today's measurement challenges along with some of the technological opportunities which offer some hope for meeting the challenges, and describes measurement technology activities currently underway in the Langley Research Center's Instrument Research Division to address modern aerospace research and design engineering requirements. Projected and realized benefits and payoffs from the ongoing measurement and instrumentation efforts will be emphasized. A discussion of future trends in the aerospace measurement technology field will be included.

Engaging Pre-Service Middle-School Teacher-Education Students in Mathematical Problem Posing: Development of an Active Learning Framework

ERIC Educational Resources Information Center

Ellerton, Nerida F.

2013-01-01

Although official curriculum documents make cursory mention of the need for problem posing in school mathematics, problem posing rarely becomes part of the implemented or assessed curriculum. This paper provides examples of how problem posing can be made an integral part of mathematics teacher education programs. It is argued that such programs…

Creativity and Mathematical Problem Posing: An Analysis of High School Students' Mathematical Problem Posing in China and the USA

ERIC Educational Resources Information Center

Van Harpen, Xianwei Y.; Sriraman, Bharath

2013-01-01

In the literature, problem-posing abilities are reported to be an important aspect/indicator of creativity in mathematics. The importance of problem-posing activities in mathematics is emphasized in educational documents in many countries, including the USA and China. This study was aimed at exploring high school students' creativity in…

Interlocked Problem Posing and Children's Problem Posing Performance in Free Structured Situations

ERIC Educational Resources Information Center

Cankoy, Osman

2014-01-01

The aim of this study is to explore the mathematical problem posing performance of students in free structured situations. Two classes of fifth grade students (N = 30) were randomly assigned to experimental and control groups. The categories of the problems posed in free structured situations by the 2 groups of students were studied through…

Problem-Posing Strategies Used by Years 8 and 9 Students

ERIC Educational Resources Information Center

Stoyanova, Elena

2005-01-01

According to Kilpatrick (1987), in the mathematics classrooms problem posing can be applied as a "goal" or as a means of instruction. Using problem posing as a goal of instruction involves asking students to respond to a range of problem-posing prompts. The main goal of this article is a classification of mathematics questions created by Years 8…

Evolution, opportunity and challenges of transboundary water and energy problems in Central Asia.

PubMed

Guo, Lidan; Zhou, Haiwei; Xia, Ziqiang; Huang, Feng

2016-01-01

Central Asia is one of the regions that suffer the most prominent transboundary water and energy problems in the world. Effective transboundary water-energy resource management and cooperation are closely related with socioeconomic development and stability in the entire Central Asia. Similar to Central Asia, Northwest China has an arid climate and is experiencing a water shortage. It is now facing imbalanced supply-demand relations of water and energy resources. These issues in Northwest China and Central Asia pose severe challenges in the implementation of the Silk Road Economic Belt strategy. Based on the analysis of water and energy distribution characteristics in Central Asia as well as demand characteristics of different countries, the complexity of local transboundary water problems was explored by reviewing corresponding historical problems of involved countries, correlated energy issues, and the evolution of inter-country water-energy cooperation. With references to experiences and lessons of five countries, contradictions, opportunities, challenges and strategies for transboundary water-energy cooperation between China and Central Asia were discussed under the promotion of the Silk Road Economic Belt construction based on current cooperation conditions.

When a Problem Is More than a Teacher's Question

ERIC Educational Resources Information Center

Olson, Jo Clay; Knott, Libby

2013-01-01

Not only are the problems teachers pose throughout their teaching of great importance but also the ways in which they use those problems make this a critical component of teaching. A problem-posing episode includes the problem setup, the statement of the problem, and the follow-up questions. Analysis of problem-posing episodes of precalculus…

Bariatric surgery for obese children and adolescents: a review of the moral challenges.

PubMed

Hofmann, Bjørn

2013-04-30

Bariatric surgery for children and adolescents is becoming widespread. However, the evidence is still scarce and of poor quality, and many of the patients are too young to consent. This poses a series of moral challenges, which have to be addressed both when considering bariatric surgery introduced as a health care service and when deciding for treatment for young individuals. A question based (Socratic) approach is applied to reveal underlying moral issues that can be relevant to an open and transparent decision making process. A wide range of moral issues with bariatric surgery for children and adolescents is identified in the literature. There is a moral imperative to help obese minors avoiding serious health problems, but there is little high quality evidence on safety, outcomes, and cost-effectiveness for bariatric surgery in this group. Lack of maturity and family relations poses a series of challenges with autonomy, informed consent, assent, and assessing the best interest of children and adolescents. Social aspects of obesity, such as medicalization, prejudice, and discrimination, raise problems with justice and trust in health professionals. Conceptual issues, such as definition of obesity and treatment end-points, present moral problems. Hidden interests of patients, parents, professionals, industry, and society need to be revealed. Performing bariatric surgery for obese children and adolescents in order to discipline their behavior warrants reflection and caution. More evidence on outcomes is needed to be able to balance benefits and risks, to provide information for a valid consent or assent, and to advise minors and parents.

Bariatric surgery for obese children and adolescents: a review of the moral challenges

PubMed Central

2013-01-01

Background Bariatric surgery for children and adolescents is becoming widespread. However, the evidence is still scarce and of poor quality, and many of the patients are too young to consent. This poses a series of moral challenges, which have to be addressed both when considering bariatric surgery introduced as a health care service and when deciding for treatment for young individuals. A question based (Socratic) approach is applied to reveal underlying moral issues that can be relevant to an open and transparent decision making process. Discussion A wide range of moral issues with bariatric surgery for children and adolescents is identified in the literature. There is a moral imperative to help obese minors avoiding serious health problems, but there is little high quality evidence on safety, outcomes, and cost-effectiveness for bariatric surgery in this group. Lack of maturity and family relations poses a series of challenges with autonomy, informed consent, assent, and assessing the best interest of children and adolescents. Social aspects of obesity, such as medicalization, prejudice, and discrimination, raise problems with justice and trust in health professionals. Conceptual issues, such as definition of obesity and treatment end-points, present moral problems. Hidden interests of patients, parents, professionals, industry, and society need to be revealed. Summary Performing bariatric surgery for obese children and adolescents in order to discipline their behavior warrants reflection and caution. More evidence on outcomes is needed to be able to balance benefits and risks, to provide information for a valid consent or assent, and to advise minors and parents. PMID:23631445

Case-Based Teaching in a Bilingual Context: Perceptions of Business Faculty in Hong Kong

ERIC Educational Resources Information Center

Jackson, Jane

2004-01-01

Case methods of teaching are now common in business education programs worldwide. This problem-based approach, however, can pose unique challenges in bilingual contexts, especially if the students are more familiar with transmission modes of learning. This paper focuses on an investigation of case-based teaching in Hong Kong. By way of surveys and…

Distinguishing How from Why the Mind Wanders: A Process-Occurrence Framework for Self-Generated Mental Activity

ERIC Educational Resources Information Center

Smallwood, Jonathan

2013-01-01

Cognition can unfold with little regard to the events taking place in the environment, and such self-generated mental activity poses a specific set of challenges for its scientific analysis in both cognitive science and neuroscience. One problem is that the spontaneous onset of self-generated mental activity makes it hard to distinguish the events…

Using Simplified English to Identify Potential Problems for Non-Native Speakers in the Language of Engineering Examination Papers

ERIC Educational Resources Information Center

Harrison, Sandra; Morgan, Roger

2012-01-01

There is an increasing sensitivity to the challenges posed by the language of examination papers and of instruction in scientific subjects, especially for non-native speakers of English. It has been observed that in addition to technical subject-specific vocabulary, non-technical words such as instructional verbs have been sources of difficulty,…

The Online Consumer: An Examination of Gender, Age, Income and Education as Determinants of Online Repurchasing

ERIC Educational Resources Information Center

Portillo, Carol D.

2017-01-01

Online purchasing has increased dramatically over the past 10 years and the pace is expected to continue to accelerate. This new channel of purchasing poses a challenge to online retailers as they strive to increase online repurchasing behavior. This non-experimental study addresses the problem of how to support a rapidly growing online…

The Availability of Instructional Media for Teaching Mentally Retarded Students in Nyanza Region, Kenya

ERIC Educational Resources Information Center

Odero, Orao Remi

2016-01-01

Learners with mental retardation pose a unique problem to the education system, one not presented by any other exceptionality. In view of the challenges and limitations of these learners, modification of both social and educational environment is fundamental in-order to attain effective schooling for them. One of the best proven medium of teaching…

Tutor System as a Source of Harmonizing the Educational System with the Needs of Economics

ERIC Educational Resources Information Center

Korsakova, Tatiana; Korsakov, Mikhail

2017-01-01

The purpose of this study is to identify the sources of harmonizing employers' orders in business and graduates of higher education. According to challenges posed by the economic environment the development of tutor-support system has the great potential to solve the problem. In the paper trends of modern specialists' educational preparation are…

Dips in Enrollment Posing Challenges for Urban Districts

ERIC Educational Resources Information Center

Gehring, John

2005-01-01

Across the U.S., urban school districts are losing students and shuttering schools. In Detroit, some 35,000 students have left the city schools in less than a decade, and the city will close 34 schools and reassign more than 10,000 students in 2006. However, the trend is not limited to Rust Belt cities like Detroit, although their problems tend to…

Creating Nurturing Environments: A Science-Based Framework for Promoting Child Health and Development within High-Poverty Neighborhoods

ERIC Educational Resources Information Center

Komro, Kelli A.; Flay, Brian R.; Biglan, Anthony

2011-01-01

Living in poverty and living in areas of concentrated poverty pose multiple risks for child development and for overall health and wellbeing. Poverty is a major risk factor for several mental, emotional, and behavioral disorders, as well as for other developmental challenges and physical health problems. In this paper, the Promise Neighborhoods…

An Analysis of Secondary and Middle School Teachers' Mathematical Problem Posing

ERIC Educational Resources Information Center

Stickles, Paula R.

2011-01-01

This study identifies the kinds of problems teachers pose when they are asked to (a) generate problems from given information and (b) create new problems from ones given to them. To investigate teachers' problem posting, preservice and inservice teachers completed background questionnaires and four problem-posing instruments. Based on previous…

Potential challenges facing distributed leadership in health care: evidence from the UK National Health Service.

PubMed

Martin, Graeme; Beech, Nic; MacIntosh, Robert; Bushfield, Stacey

2015-01-01

The discourse of leaderism in health care has been a subject of much academic and practical debate. Recently, distributed leadership (DL) has been adopted as a key strand of policy in the UK National Health Service (NHS). However, there is some confusion over the meaning of DL and uncertainty over its application to clinical and non-clinical staff. This article examines the potential for DL in the NHS by drawing on qualitative data from three co-located health-care organisations that embraced DL as part of their organisational strategy. Recent theorising positions DL as a hybrid model combining focused and dispersed leadership; however, our data raise important challenges for policymakers and senior managers who are implementing such a leadership policy. We show that there are three distinct forms of disconnect and that these pose a significant problem for DL. However, we argue that instead of these disconnects posing a significant problem for the discourse of leaderism, they enable a fantasy of leadership that draws on and supports the discourse. © 2014 The Authors. Sociology of Health & Illness © 2014 Foundation for the Sociology of Health & Illness/John Wiley & Sons Ltd.

Reentry challenges facing women with mental health problems.

PubMed

Visher, Christy A; Bakken, Nicholas W

2014-01-01

Women entering the correctional system represent a population at high risk for mental health and the body of research on the mental health needs of women offenders is growing. These mental health problems pose challenges for women at every stage of the criminal justice process, from arrest to incarceration to community reentry and reintegration. In this article, we examined mental health status among a sample of 142 women leaving confinement and the role that mental health problems played in shaping their reentry outcomes using data collected between 2002 and 2005 in Houston, Texas. In the year after leaving prison, women with mental health problems reported poorer health, more hospitalizations, more suicidal thoughts, greater difficulties securing housing and employment, more involvement in criminal behavior, and less financial support from family than women with no indication of mental health problems. However, mental health status did not increase the likelihood of substance use relapse or reincarceration. The article concludes with a discussion of recommendations for improved policy and practice.

The study of direct-to-consumer advertising for prescription drugs.

PubMed

Schommer, Jon C; Hansen, Richard A

2005-06-01

The objectives of this article are to (1) identify key methodological issues related to investigating the effects of direct-to-consumer advertising (DTCA) for prescription drugs, (2) highlight opportunities and challenges that these issues pose, and (3) provide suggestions to address these challenges and opportunities from a social and administrative pharmacy perspective. Through a review of existing literature and consultation with research colleagues, we identified 3 broad issues regarding the study of DTCA for prescription drugs: (1) the importance of problem formulation, (2) the role of health behavior and decision-making perspectives, and (3) data collection and data analysis challenges and opportunities. Based upon our findings, we developed recommendations for future research in this area. Clear problem formulation will be instructive for prioritizing research needs and for determining the role that health behavior and decision-making perspectives can serve in DTCA research. In addition, it appears that cluster bias, nonlinear relationships, mediating/moderating effects, time effects, acquiescent response, and case mix are particularly salient challenges for the DTCA research domain. We suggest that problem formulation, selection of sound theories upon which to base research, and data collection and data analysis challenges are key methodological issues related to investigating the effects of DTCA for prescription drugs.

Analysis of Problems Posed by Sixth-Grade Middle School Students for the Addition of Fractions in Terms of Semantic Structures

ERIC Educational Resources Information Center

Kar, Tugrul

2015-01-01

This study aimed to investigate how the semantic structures of problems posed by sixth-grade middle school students for the addition of fractions affect their problem-posing performance. The students were presented with symbolic operations involving the addition of fractions and asked to pose two different problems related to daily-life situations…

[Medical cooperation on the internet].

PubMed

Meier, N; Lenzen, H; Renger, B C

1998-01-01

Post-1999, the economically united EEC will pose new challenges to European business, industry and citizen. It is a key objective that in the domain of European "infostructure" these problems are challenged and overcome, and that "advanced communications technologies and services" (ACTS) become the cement which binds the Community together. Within ACTS, 130 different projects are building new services. The consortium Emerald develops a telemedicine platform, setting up teleworking with teleconference, computer supported co-operative work (cscw, joint editing), demonstration and teleteaching for radiology, cardiology, nuclear medicine and radio surgery working environments.

Systems engineering for very large systems

NASA Technical Reports Server (NTRS)

Lewkowicz, Paul E.

1993-01-01

Very large integrated systems have always posed special problems for engineers. Whether they are power generation systems, computer networks or space vehicles, whenever there are multiple interfaces, complex technologies or just demanding customers, the challenges are unique. 'Systems engineering' has evolved as a discipline in order to meet these challenges by providing a structured, top-down design and development methodology for the engineer. This paper attempts to define the general class of problems requiring the complete systems engineering treatment and to show how systems engineering can be utilized to improve customer satisfaction and profit ability. Specifically, this work will focus on a design methodology for the largest of systems, not necessarily in terms of physical size, but in terms of complexity and interconnectivity.

Systems engineering for very large systems

NASA Astrophysics Data System (ADS)

Lewkowicz, Paul E.

Very large integrated systems have always posed special problems for engineers. Whether they are power generation systems, computer networks or space vehicles, whenever there are multiple interfaces, complex technologies or just demanding customers, the challenges are unique. 'Systems engineering' has evolved as a discipline in order to meet these challenges by providing a structured, top-down design and development methodology for the engineer. This paper attempts to define the general class of problems requiring the complete systems engineering treatment and to show how systems engineering can be utilized to improve customer satisfaction and profit ability. Specifically, this work will focus on a design methodology for the largest of systems, not necessarily in terms of physical size, but in terms of complexity and interconnectivity.

Unraveling the Mystery of the Origin of Mathematical Problems: Using a Problem-Posing Framework with Prospective Mathematics Teachers

ERIC Educational Resources Information Center

Contreras, Jose

2007-01-01

In this article, I model how a problem-posing framework can be used to enhance our abilities to systematically generate mathematical problems by modifying the attributes of a given problem. The problem-posing model calls for the application of the following fundamental mathematical processes: proving, reversing, specializing, generalizing, and…

A New Problem-Posing Approach Based on Problem-Solving Strategy: Analyzing Pre-Service Primary School Teachers' Performance

ERIC Educational Resources Information Center

Kiliç, Çigdem

2017-01-01

This study examined pre-service primary school teachers' performance in posing problems that require knowledge of problem-solving strategies. Quantitative and qualitative methods were combined. The 120 participants were asked to pose a problem that could be solved by using the find-a-pattern a particular problem-solving strategy. After that,…

Testing Scientific Software: A Systematic Literature Review.

PubMed

Kanewala, Upulee; Bieman, James M

2014-10-01

Scientific software plays an important role in critical decision making, for example making weather predictions based on climate models, and computation of evidence for research publications. Recently, scientists have had to retract publications due to errors caused by software faults. Systematic testing can identify such faults in code. This study aims to identify specific challenges, proposed solutions, and unsolved problems faced when testing scientific software. We conducted a systematic literature survey to identify and analyze relevant literature. We identified 62 studies that provided relevant information about testing scientific software. We found that challenges faced when testing scientific software fall into two main categories: (1) testing challenges that occur due to characteristics of scientific software such as oracle problems and (2) testing challenges that occur due to cultural differences between scientists and the software engineering community such as viewing the code and the model that it implements as inseparable entities. In addition, we identified methods to potentially overcome these challenges and their limitations. Finally we describe unsolved challenges and how software engineering researchers and practitioners can help to overcome them. Scientific software presents special challenges for testing. Specifically, cultural differences between scientist developers and software engineers, along with the characteristics of the scientific software make testing more difficult. Existing techniques such as code clone detection can help to improve the testing process. Software engineers should consider special challenges posed by scientific software such as oracle problems when developing testing techniques.

Evidence-Informed, Individual Treatment of a Child with Sexual Behavior Problems: A Case Study.

PubMed

Allen, Brian; Berliner, Lucy

2015-11-01

Children with sexual behavior problems pose a significant challenge for community-based mental health clinicians. Very few clinical trials are available to guide intervention and those interventions that are available are based in a group format. The current case study demonstrates the application of evidence-informed treatment techniques during the individual treatment of a 10-year-old boy displaying interpersonal sexual behavior problems. Specifically, the clinician adapts and implements a group-based model developed and tested by Bonner et al. (1999) for use with an individual child and his caregivers. Key points of the case study are discussed within the context of implementing evidence-informed treatments for children with sexual behavior problems.

Trends and Innovations in Higher Education Reform: Worldwide, Latin America and in the Caribbean. Research & Occasional Paper Series: CSHE.12.10

ERIC Educational Resources Information Center

Segrera, Francisco Lopez

2010-01-01

Universities in Latin America and in the Caribbean (LAC), and throughout the world, are facing one of the most challenging eras in their history. Globalization presents many important opportunities for higher education, but also poses serious problems and raises questions about how best to serve the common good. The traditional values of…

Artifacts as Sources for Problem-Posing Activities

ERIC Educational Resources Information Center

Bonotto, Cinzia

2013-01-01

The problem-posing process represents one of the forms of authentic mathematical inquiry which, if suitably implemented in classroom activities, could move well beyond the limitations of word problems, at least as they are typically utilized. The two exploratory studies presented sought to investigate the impact of "problem-posing" activities when…

The Art of Problem Posing. 3rd Edition

ERIC Educational Resources Information Center

Brown, Stephen I.; Walter, Marion I.

2005-01-01

The new edition of this classic book describes and provides a myriad of examples of the relationships between problem posing and problem solving, and explores the educational potential of integrating these two activities in classrooms at all levels. "The Art of Problem Posing, Third Edition" encourages readers to shift their thinking…

An Investigation on Chinese Teachers' Realistic Problem Posing and Problem Solving Ability and Beliefs

ERIC Educational Resources Information Center

Chen, Limin; Van Dooren, Wim; Chen, Qi; Verschaffel, Lieven

2011-01-01

In the present study, which is a part of a research project about realistic word problem solving and problem posing in Chinese elementary schools, a problem solving and a problem posing test were administered to 128 pre-service and in-service elementary school teachers from Tianjin City in China, wherein the teachers were asked to solve 3…

Enhancing students’ mathematical problem posing skill through writing in performance tasks strategy

NASA Astrophysics Data System (ADS)

Kadir; Adelina, R.; Fatma, M.

2018-01-01

Many researchers have studied the Writing in Performance Task (WiPT) strategy in learning, but only a few paid attention on its relation to the problem-posing skill in mathematics. The problem-posing skill in mathematics covers problem reformulation, reconstruction, and imitation. The purpose of the present study was to examine the effect of WiPT strategy on students’ mathematical problem-posing skill. The research was conducted at a Public Junior Secondary School in Tangerang Selatan. It used a quasi-experimental method with randomized control group post-test. The samples were 64 students consists of 32 students of the experiment group and 32 students of the control. A cluster random sampling technique was used for sampling. The research data were obtained by testing. The research shows that the problem-posing skill of students taught by WiPT strategy is higher than students taught by a conventional strategy. The research concludes that the WiPT strategy is more effective in enhancing the students’ mathematical problem-posing skill compared to the conventional strategy.

Perceptions of the importance and control of professional problems in the clinical setting.

PubMed

Maupomé, G; Borges-Yáñez, S A; Dáez-de-Bonilla, F J; Pineda-Cruz, A

2001-01-01

The objective of this study was to identify the relative importance of culturally relevant professional problems and the degree of control over them, as perceived by dentists and dental students in Mexico City, Mexico. The dentists and students ranked 13 problems according to importance and then according to the perceived degree of control over each one. Novice clinicians were less secure about their ability to cope with the legal, financial, and clinical performance problems, whereas experienced clinicians were more concerned about occupational hazards and the dental market and culture. Both reported similar perceptions of their control of the problems. This preliminary information should support introducing into dental schools relevant practice-management courses, targeting continuing education efforts, and instituting professional counseling measures to meet the challenges posed by these problems.

Dissecting Success Stories on Mathematical Problem Posing: A Case of the Billiard Task

ERIC Educational Resources Information Center

Koichu, Boris; Kontorovich, Igor

2013-01-01

"Success stories," i.e., cases in which mathematical problems posed in a controlled setting are perceived by the problem posers or other individuals as interesting, cognitively demanding, or surprising, are essential for understanding the nature of problem posing. This paper analyzes two success stories that occurred with individuals of different…

What Makes a Problem Mathematically Interesting? Inviting Prospective Teachers to Pose Better Problems

ERIC Educational Resources Information Center

Crespo, Sandra; Sinclair, Nathalie

2008-01-01

School students of all ages, including those who subsequently become teachers, have limited experience posing their own mathematical problems. Yet problem posing, both as an act of mathematical inquiry and of mathematics teaching, is part of the mathematics education reform vision that seeks to promote mathematics as an worthy intellectual…

Helping Young Students to Better Pose an Environmental Problem

ERIC Educational Resources Information Center

Pruneau, Diane; Freiman, Viktor; Barbier, Pierre-Yves; Langis, Joanne

2009-01-01

Grade 3 students were asked to solve a sedimentation problem in a local river. With scientists, students explored many aspects of the problem and proposed solutions. Graphic representation tools were used to help students to better pose the problem. Using questionnaires and interviews, researchers observed students' capacity to pose the problem…

University Students' Problem Posing Abilities and Attitudes towards Mathematics.

ERIC Educational Resources Information Center

Grundmeier, Todd A.

2002-01-01

Explores the problem posing abilities and attitudes towards mathematics of students in a university pre-calculus class and a university mathematical proof class. Reports a significant difference in numeric posing versus non-numeric posing ability in both classes. (Author/MM)

Advancing RF pulse design using an open-competition format: Report from the 2015 ISMRM challenge.

PubMed

Grissom, William A; Setsompop, Kawin; Hurley, Samuel A; Tsao, Jeffrey; Velikina, Julia V; Samsonov, Alexey A

2017-10-01

To advance the best solutions to two important RF pulse design problems with an open head-to-head competition. Two sub-challenges were formulated in which contestants competed to design the shortest simultaneous multislice (SMS) refocusing pulses and slice-selective parallel transmission (pTx) excitation pulses, subject to realistic hardware and safety constraints. Short refocusing pulses are needed for spin echo SMS imaging at high multiband factors, and short slice-selective pTx pulses are needed for multislice imaging in ultra-high field MRI. Each sub-challenge comprised two phases, in which the first phase posed problems with a low barrier of entry, and the second phase encouraged solutions that performed well in general. The Challenge ran from October 2015 to May 2016. The pTx Challenge winners developed a spokes pulse design method that combined variable-rate selective excitation with an efficient method to enforce SAR constraints, which achieved 10.6 times shorter pulse durations than conventional approaches. The SMS Challenge winners developed a time-optimal control multiband pulse design algorithm that achieved 5.1 times shorter pulse durations than conventional approaches. The Challenge led to rapid step improvements in solutions to significant problems in RF excitation for SMS imaging and ultra-high field MRI. Magn Reson Med 78:1352-1361, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Effects of the Problem-Posing Approach on Students' Problem Solving Skills and Metacognitive Awareness in Science Education

NASA Astrophysics Data System (ADS)

Akben, Nimet

2018-05-01

The interrelationship between mathematics and science education has frequently been emphasized, and common goals and approaches have often been adopted between disciplines. Improving students' problem-solving skills in mathematics and science education has always been given special attention; however, the problem-posing approach which plays a key role in mathematics education has not been commonly utilized in science education. As a result, the purpose of this study was to better determine the effects of the problem-posing approach on students' problem-solving skills and metacognitive awareness in science education. This was a quasi-experimental based study conducted with 61 chemistry and 40 physics students; a problem-solving inventory and a metacognitive awareness inventory were administered to participants both as a pre-test and a post-test. During the 2017-2018 academic year, problem-solving activities based on the problem-posing approach were performed with the participating students during their senior year in various university chemistry and physics departments throughout the Republic of Turkey. The study results suggested that structured, semi-structured, and free problem-posing activities improve students' problem-solving skills and metacognitive awareness. These findings indicated not only the usefulness of integrating problem-posing activities into science education programs but also the need for further research into this question.

Using physics-based pose predictions and free energy perturbation calculations to predict binding poses and relative binding affinities for FXR ligands in the D3R Grand Challenge 2

NASA Astrophysics Data System (ADS)

Athanasiou, Christina; Vasilakaki, Sofia; Dellis, Dimitris; Cournia, Zoe

2018-01-01

Computer-aided drug design has become an integral part of drug discovery and development in the pharmaceutical and biotechnology industry, and is nowadays extensively used in the lead identification and lead optimization phases. The drug design data resource (D3R) organizes challenges against blinded experimental data to prospectively test computational methodologies as an opportunity for improved methods and algorithms to emerge. We participated in Grand Challenge 2 to predict the crystallographic poses of 36 Farnesoid X Receptor (FXR)-bound ligands and the relative binding affinities for two designated subsets of 18 and 15 FXR-bound ligands. Here, we present our methodology for pose and affinity predictions and its evaluation after the release of the experimental data. For predicting the crystallographic poses, we used docking and physics-based pose prediction methods guided by the binding poses of native ligands. For FXR ligands with known chemotypes in the PDB, we accurately predicted their binding modes, while for those with unknown chemotypes the predictions were more challenging. Our group ranked #1st (based on the median RMSD) out of 46 groups, which submitted complete entries for the binding pose prediction challenge. For the relative binding affinity prediction challenge, we performed free energy perturbation (FEP) calculations coupled with molecular dynamics (MD) simulations. FEP/MD calculations displayed a high success rate in identifying compounds with better or worse binding affinity than the reference (parent) compound. Our studies suggest that when ligands with chemical precedent are available in the literature, binding pose predictions using docking and physics-based methods are reliable; however, predictions are challenging for ligands with completely unknown chemotypes. We also show that FEP/MD calculations hold predictive value and can nowadays be used in a high throughput mode in a lead optimization project provided that crystal structures of sufficiently high quality are available.

Distributed Prognostic Health Management with Gaussian Process Regression

NASA Technical Reports Server (NTRS)

Saha, Sankalita; Saha, Bhaskar; Saxena, Abhinav; Goebel, Kai Frank

2010-01-01

Distributed prognostics architecture design is an enabling step for efficient implementation of health management systems. A major challenge encountered in such design is formulation of optimal distributed prognostics algorithms. In this paper. we present a distributed GPR based prognostics algorithm whose target platform is a wireless sensor network. In addition to challenges encountered in a distributed implementation, a wireless network poses constraints on communication patterns, thereby making the problem more challenging. The prognostics application that was used to demonstrate our new algorithms is battery prognostics. In order to present trade-offs within different prognostic approaches, we present comparison with the distributed implementation of a particle filter based prognostics for the same battery data.

Analyzing Pre-Service Primary Teachers' Fraction Knowledge Structures through Problem Posing

ERIC Educational Resources Information Center

Kilic, Cigdem

2015-01-01

In this study it was aimed to determine pre-service primary teachers' knowledge structures of fraction through problem posing activities. A total of 90 pre-service primary teachers participated in this study. A problem posing test consisting of two questions was used and the participants were asked to generate as many as problems based on the…

Students’ Mathematical Creative Thinking through Problem Posing Learning

NASA Astrophysics Data System (ADS)

Ulfah, U.; Prabawanto, S.; Jupri, A.

2017-09-01

The research aims to investigate the differences in enhancement of students’ mathematical creative thinking ability of those who received problem posing approach assisted by manipulative media and students who received problem posing approach without manipulative media. This study was a quasi experimental research with non-equivalent control group design. Population of this research was third-grade students of a primary school in Bandung city in 2016/2017 academic year. Sample of this research was two classes as experiment class and control class. The instrument used is a test of mathematical creative thinking ability. Based on the results of the research, it is known that the enhancement of the students’ mathematical creative thinking ability of those who received problem posing approach with manipulative media aid is higher than the ability of those who received problem posing approach without manipulative media aid. Students who get learning problem posing learning accustomed in arranging mathematical sentence become matter of story so it can facilitate students to comprehend about story

Perceiving emotion: towards a realistic understanding of the task.

PubMed

Cowie, Roddy

2009-12-12

A decade ago, perceiving emotion was generally equated with taking a sample (a still photograph or a few seconds of speech) that unquestionably signified an archetypal emotional state, and attaching the appropriate label. Computational research has shifted that paradigm in multiple ways. Concern with realism is key. Emotion generally colours ongoing action and interaction: describing that colouring is a different problem from categorizing brief episodes of relatively pure emotion. Multiple challenges flow from that. Describing emotional colouring is a challenge in itself. One approach is to use everyday categories describing states that are partly emotional and partly cognitive. Another approach is to use dimensions. Both approaches need ways to deal with gradual changes over time and mixed emotions. Attaching target descriptions to a sample poses problems of both procedure and validation. Cues are likely to be distributed both in time and across modalities, and key decisions may depend heavily on context. The usefulness of acted data is limited because it tends not to reproduce these features. By engaging with these challenging issues, research is not only achieving impressive results, but also offering a much deeper understanding of the problem.

Geophysical Tools, Challenges and Perspectives Related to Natural Hazards, Climate Change and Food Security

NASA Astrophysics Data System (ADS)

Fucugauchi, J. U.

2013-05-01

In the coming decades a changing climate and natural hazards will likely increase the vulnerability of agricultural and other food production infrastructures, posing increasing treats to industrialized and developing economies. While food security concerns affect us globally, the huge differences among countries in stocks, population size, poverty levels, economy, technologic development, transportation, health care systems and basic infrastructure will pose a much larger burden on populations in the developing and less developed world. In these economies, increase in the magnitude, duration and frequency of droughts, floods, hurricanes, rising sea levels, heat waves, thunderstorms, freezing events and other phenomena will pose severe costs on the population. For this presentation, we concentrate on a geophysical perspective of the problems, tools available, challenges and short and long-term perspectives. In many instances, a range of natural hazards are considered as unforeseen catastrophes, which suddenly affect without warning, resulting in major losses. Although the forecasting capacity in the different situations arising from climate change and natural hazards is still limited, there are a range of tools available to assess scenarios and forecast models for developing and implementing better mitigation strategies and prevention programs. Earth observation systems, geophysical instrumental networks, satellite observatories, improved understanding of phenomena, expanded global and regional databases, geographic information systems, higher capacity for computer modeling, numerical simulations, etc provide a scientific-technical framework for developing strategies. Hazard prevention and mitigation programs will result in high costs globally, however major costs and challenges concentrate on the less developed economies already affected by poverty, famines, health problems, social inequalities, poor infrastructure, low life expectancy, high population growth, inadequate education systems, immigration, economic crises, conflicts and other issues. Case history analyses and proposals for collaboration programs, know-how transfer and better use of geophysical tools, data, observatories and monitoring networks will be discussed.

Treatment of Nuclear Data Covariance Information in Sample Generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swiler, Laura Painton; Adams, Brian M.; Wieselquist, William

This report summarizes a NEAMS (Nuclear Energy Advanced Modeling and Simulation) project focused on developing a sampling capability that can handle the challenges of generating samples from nuclear cross-section data. The covariance information between energy groups tends to be very ill-conditioned and thus poses a problem using traditional methods for generated correlated samples. This report outlines a method that addresses the sample generation from cross-section matrices.

BioSim (trademark) BG Non-Biological Aerosol Simulant

DTIC Science & Technology

2004-11-17

39.5 1.36 1,1- difluoroethane HFA 152a – Not used for pharmaceutical inhalers , is used for personal products Boiling point (-13o F) 63 (psig... 1 BIOSIMTM BG NON-BIOLOGICAL AEROSOL SIMULANT David S. Alburty, Kelly L. Brown, Jennifer L. Dannehl and Andrew E. Page Midwest...BioSafey Level 1 regulations. All of these materials of biological origin pose challenging logistics problems including safety issues, cost

Terrain, weather pose challenges in Minnesota project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trojack, L.

1994-12-01

This paper briefly reviews an innovative method used in installing a natural gas pipeline in Minnesota which traversed a marsh area. Because of the special problems associated with this wetland area, special equipment and techniques had to be used to minimize disturbance associated with the construction. It describes the equipment and the resulting performance the equipment had. It proved to significantly reduce disturbance and result in minimum site restoration work.

Analysis of Strategy and Strategies of Analysis

DTIC Science & Technology

2008-01-01

thus expand- ing its resource base and power, permitted Pax Britannia and guaran- teed national security and prosperity. Today, China’s effort to...deter- mined by the reasoning that buttresses it. This poses a serious problem for making strategy under fluid conditions, such as those that define...enhance its core strengths and preserve its advantages, given their utility vis-à- vis its challenges. The result: Pax Britannia . Once again, corporate

Music Students' Perception of the Use of Multi-Media Technology at the Graduate Level in Hong Kong Higher Education

ERIC Educational Resources Information Center

Ho, Wai-Chung

2007-01-01

The core purpose of this paper is to draw together research issues and concrete problems with the use of multimedia technology at the graduate level in higher music education by examining one university's responses to the challenges posed by the use of multimedia technology as a teaching and learning aid for music education. Between June and July…

Conceptual and methodological issues in research on mindfulness and meditation.

PubMed

Davidson, Richard J; Kaszniak, Alfred W

2015-10-01

Both basic science and clinical research on mindfulness, meditation, and related constructs have dramatically increased in recent years. However, interpretation of these research results has been challenging. The present article addresses unique conceptual and methodological problems posed by research in this area. Included among the key topics is the role of first-person experience and how it can be best studied, the challenges posed by intervention research designs in which true double-blinding is not possible, the nature of control and comparison conditions for research that includes mindfulness or other meditation-based interventions, issues in the adequate description of mindfulness and related trainings and interventions, the question of how mindfulness can be measured, questions regarding what can and cannot be inferred from self-report measures, and considerations regarding the structure of study design and data analyses. Most of these topics are germane to both basic and clinical research studies and have important bearing on the future scientific understanding of mindfulness and meditation. (c) 2015 APA, all rights reserved).

Conceptual and Methodological Issues in Research on Mindfulness and Meditation

PubMed Central

Davidson, Richard J.; Kaszniak, Alfred W.

2015-01-01

Both basic science and clinical research on mindfulness, meditation, and related constructs has dramatically increased in recent years. However, interpretation of these research results has been challenging. The present article addresses unique conceptual and methodological problems posed by research in this area. Included among the key topics is the role of first person experience and how it can be best studied; the challenges posed by intervention research designs in which true double-blinding is not possible; the nature of control and comparison conditions for research that includes mindfulness or other meditation-based interventions; issues in the adequate description of mindfulness and related trainings and interventions; the question of how mindfulness can be measured; questions regarding what can and cannot be inferred from self-report measures; and considerations regarding the structure of study design and data analyses. Most of these topics are germane to both basic and clinical research studies and have important bearing on the future scientific understanding of mindfulness and meditation. PMID:26436310

Algorithms and Array Design Criteria for Robust Imaging in Interferometry

NASA Astrophysics Data System (ADS)

Kurien, Binoy George

Optical interferometry is a technique for obtaining high-resolution imagery of a distant target by interfering light from multiple telescopes. Image restoration from interferometric measurements poses a unique set of challenges. The first challenge is that the measurement set provides only a sparse-sampling of the object's Fourier Transform and hence image formation from these measurements is an inherently ill-posed inverse problem. Secondly, atmospheric turbulence causes severe distortion of the phase of the Fourier samples. We develop array design conditions for unique Fourier phase recovery, as well as a comprehensive algorithmic framework based on the notion of redundant-spaced-calibration (RSC), which together achieve reliable image reconstruction in spite of these challenges. Within this framework, we see that classical interferometric observables such as the bispectrum and closure phase can limit sensitivity, and that generalized notions of these observables can improve both theoretical and empirical performance. Our framework leverages techniques from lattice theory to resolve integer phase ambiguities in the interferometric phase measurements, and from graph theory, to select a reliable set of generalized observables. We analyze the expected shot-noise-limited performance of our algorithm for both pairwise and Fizeau interferometric architectures and corroborate this analysis with simulation results. We apply techniques from the field of compressed sensing to perform image reconstruction from the estimates of the object's Fourier coefficients. The end result is a comprehensive strategy to achieve well-posed and easily-predictable reconstruction performance in optical interferometry.

Process-based Assignment-Setting Change for Support of Overcoming Bottlenecks in Learning by Problem-Posing in Arithmetic Word Problems

NASA Astrophysics Data System (ADS)

Supianto, A. A.; Hayashi, Y.; Hirashima, T.

2017-02-01

Problem-posing is well known as an effective activity to learn problem-solving methods. Monsakun is an interactive problem-posing learning environment to facilitate arithmetic word problems learning for one operation of addition and subtraction. The characteristic of Monsakun is problem-posing as sentence-integration that lets learners make a problem of three sentences. Monsakun provides learners with five or six sentences including dummies, which are designed through careful considerations by an expert teacher as a meaningful distraction to the learners in order to learn the structure of arithmetic word problems. The results of the practical use of Monsakun in elementary schools show that many learners have difficulties in arranging the proper answer at the high level of assignments. The analysis of the problem-posing process of such learners found that their misconception of arithmetic word problems causes impasses in their thinking and mislead them to use dummies. This study proposes a method of changing assignments as a support for overcoming bottlenecks of thinking. In Monsakun, the bottlenecks are often detected as a frequently repeated use of a specific dummy. If such dummy can be detected, it is the key factor to support learners to overcome their difficulty. This paper discusses how to detect the bottlenecks and to realize such support in learning by problem-posing.

The Problems Posed and Models Employed by Primary School Teachers in Subtraction with Fractions

ERIC Educational Resources Information Center

Iskenderoglu, Tuba Aydogdu

2017-01-01

Students have difficulties in solving problems of fractions in almost all levels, and in problem posing. Problem posing skills influence the process of development of the behaviors observed at the level of comprehension. That is why it is very crucial for teachers to develop activities for student to have conceptual comprehension of fractions and…

Testing Scientific Software: A Systematic Literature Review

PubMed Central

Kanewala, Upulee; Bieman, James M.

2014-01-01

Context Scientific software plays an important role in critical decision making, for example making weather predictions based on climate models, and computation of evidence for research publications. Recently, scientists have had to retract publications due to errors caused by software faults. Systematic testing can identify such faults in code. Objective This study aims to identify specific challenges, proposed solutions, and unsolved problems faced when testing scientific software. Method We conducted a systematic literature survey to identify and analyze relevant literature. We identified 62 studies that provided relevant information about testing scientific software. Results We found that challenges faced when testing scientific software fall into two main categories: (1) testing challenges that occur due to characteristics of scientific software such as oracle problems and (2) testing challenges that occur due to cultural differences between scientists and the software engineering community such as viewing the code and the model that it implements as inseparable entities. In addition, we identified methods to potentially overcome these challenges and their limitations. Finally we describe unsolved challenges and how software engineering researchers and practitioners can help to overcome them. Conclusions Scientific software presents special challenges for testing. Specifically, cultural differences between scientist developers and software engineers, along with the characteristics of the scientific software make testing more difficult. Existing techniques such as code clone detection can help to improve the testing process. Software engineers should consider special challenges posed by scientific software such as oracle problems when developing testing techniques. PMID:25125798

Problem-Posing Research in Mathematics Education: Looking Back, Looking Around, and Looking Ahead

ERIC Educational Resources Information Center

Silver, Edward A.

2013-01-01

In this paper, I comment on the set of papers in this special issue on mathematical problem posing. I offer some observations about the papers in relation to several key issues, and I suggest some productive directions for continued research inquiry on mathematical problem posing.

'She's my sister-in-law, my visitor, my friend' -- challenges of staff identity in home follow-up in an HIV trial in Western Kenya.

PubMed

Madiega, Philister Adhiambo; Jones, Gemma; Prince, Ruth Jane; Geissler, Paul Wenzel

2013-04-01

Identities ascribed to research staff in face-to-face encounters with participants have been raised as key ethical challenge in transnational health research. 'Misattributed' identities that do not just deviate from researchers' self-image, but obscure unequivocal aspects of researcher identity - e.g. that they are researchers - are a case of such ethical problem. Yet, the reasonable expectation of unconcealed identity can conflict with another ethical premise: confidentiality; this poses challenges to staff visiting participants at home. We explore these around a case study of 'follow-up' staff, observed during an ethnographic study of a Kenyan HIV 'trial community', which included participant observation, conversations, and interviews with staff (n = 79) and participants (n = 89). We found that because of the need to maintain confidentiality and because of some suspicions towards researchers, research staff drew upon alternative identities - presenting themselves to non-participants as relatives or friends, rather than as researchers. Several staff experienced this as necessary but uncomfortable. Simultaneously, staff and participants forged close relations in line with their fictional identities, which however also posed challenges because they entailed personal responsibilities that were difficult to live up to, due to limited resources, and the trial's limited duration. Similar challenges may arise in transnational HIV treatment programmes and should be explored further in that context. © 2013 Blackwell Publishing Ltd.

Eco-analytical Methodology in Environmental Problems Monitoring

NASA Astrophysics Data System (ADS)

Agienko, M. I.; Bondareva, E. P.; Chistyakova, G. V.; Zhironkina, O. V.; Kalinina, O. I.

2017-01-01

Among the problems common to all mankind, which solutions influence the prospects of civilization, the problem of ecological situation monitoring takes very important place. Solution of this problem requires specific methodology based on eco-analytical comprehension of global issues. Eco-analytical methodology should help searching for the optimum balance between environmental problems and accelerating scientific and technical progress. The fact that Governments, corporations, scientists and nations focus on the production and consumption of material goods cause great damage to environment. As a result, the activity of environmentalists is developing quite spontaneously, as a complement to productive activities. Therefore, the challenge posed by the environmental problems for the science is the formation of geo-analytical reasoning and the monitoring of global problems common for the whole humanity. So it is expected to find the optimal trajectory of industrial development to prevent irreversible problems in the biosphere that could stop progress of civilization.

An Exploratory Framework for Handling the Complexity of Mathematical Problem Posing in Small Groups

ERIC Educational Resources Information Center

Kontorovich, Igor; Koichu, Boris; Leikin, Roza; Berman, Avi

2012-01-01

The paper introduces an exploratory framework for handling the complexity of students' mathematical problem posing in small groups. The framework integrates four facets known from past research: task organization, students' knowledge base, problem-posing heuristics and schemes, and group dynamics and interactions. In addition, it contains a new…

Problem Posing at All Levels in the Calculus Classroom

ERIC Educational Resources Information Center

Perrin, John Robert

2007-01-01

This article explores the use of problem posing in the calculus classroom using investigative projects. Specially, four examples of student work are examined, each one differing in originality of problem posed. By allowing students to explore actual questions that they have about calculus, coming from their own work or class discussion, or…

Critical Inquiry across the Disciplines: Strategies for Student-Generated Problem Posing

ERIC Educational Resources Information Center

Nardone, Carroll Ferguson; Lee, Renee Gravois

2011-01-01

Problem posing is a higher-order, active-learning task that is important for students to develop. This article describes a series of interdisciplinary learning activities designed to help students strengthen their problem-posing skills, which requires that students become more responsible for their learning and that faculty move to a facilitator…

Developing Teachers' Subject Didactic Competence through Problem Posing

ERIC Educational Resources Information Center

Ticha, Marie; Hospesova, Alena

2013-01-01

Problem posing (not only in lesson planning but also directly in teaching whenever needed) is one of the attributes of a teacher's subject didactic competence. In this paper, problem posing in teacher education is understood as an educational and a diagnostic tool. The results of the study were gained in pre-service primary school teacher…

The Impact of Problem Posing on Elementary Teachers' Beliefs about Mathematics and Mathematics Teaching

ERIC Educational Resources Information Center

Barlow, Angela T.; Cates, Janie M.

2006-01-01

This study investigated the impact of incorporating problem posing in elementary classrooms on the beliefs held by elementary teachers about mathematics and mathematics teaching. Teachers participated in a year-long staff development project aimed at facilitating the incorporation of problem posing into their classrooms. Beliefs were examined via…

The Posing of Arithmetic Problems by Mathematically Talented Students

ERIC Educational Resources Information Center

Espinoza González, Johan; Lupiáñez Gómez, José Luis; Segovia Alex, Isidoro

2016-01-01

Introduction: This paper analyzes the arithmetic problems posed by a group of mathematically talented students when given two problem-posing tasks, and compares these students' responses to those given by a standard group of public school students to the same tasks. Our analysis focuses on characterizing and identifying the differences between the…

Posing Problems to Understand Children's Learning of Fractions

ERIC Educational Resources Information Center

Cheng, Lu Pien

2013-01-01

In this study, ways in which problem posing activities aid our understanding of children's learning of addition of unlike fractions and product of proper fractions was examined. In particular, how a simple problem posing activity helps teachers take a second, deeper look at children's understanding of fraction concepts will be discussed. The…

Development of the Structured Problem Posing Skills and Using Metaphoric Perceptions

ERIC Educational Resources Information Center

Arikan, Elif Esra; Unal, Hasan

2014-01-01

The purpose of this study was to introduce problem posing activity to third grade students who have never met before. This study was also explored students' metaphorical images on problem posing process. Participants were from Public school in Marmara Region in Turkey. Data was analyzed both qualitatively (content analysis for difficulty and…

Integrating Worked Examples into Problem Posing in a Web-Based Learning Environment

ERIC Educational Resources Information Center

Hsiao, Ju-Yuan; Hung, Chun-Ling; Lan, Yu-Feng; Jeng, Yoau-Chau

2013-01-01

Most students always lack of experience and perceive difficult regarding problem posing. The study hypothesized that worked examples may have benefits for supporting students' problem posing activities. A quasi-experiment was conducted in the context of a business mathematics course for examining the effects of integrating worked examples into…

Malnutrition and poverty.

PubMed

Peña, Manuel; Bacallao, Jorge

2002-01-01

This paper is an attempt to discuss the problem of malnutrition within the framework of the global need for development and the challenges posed by the trends of neoliberalism and globalization. We argue that there is a two-way link between poverty and health in which nutrition plays an important role both as an active and as a mediating factor. Key concepts are exposed and expanded: (a) Development per se does not ensure better health; (b) unequal distribution of income has an independent effect on health indicators after adjusting for total income; (c) improving health can make an important contribution to reducing poverty; (d ) improving nutrition throughout the whole life course is an indispensable strategy for better health; (e) obesity has to be included amongst the most critical health problems, has different traits, and presents with different challenges in the developing world and in the industrialized countries.

Review of battery powered embedded systems design for mission-critical low-power applications

NASA Astrophysics Data System (ADS)

Malewski, Matthew; Cowell, David M. J.; Freear, Steven

2018-06-01

The applications and uses of embedded systems is increasingly pervasive. Mission and safety critical systems relying on embedded systems pose specific challenges. Embedded systems is a multi-disciplinary domain, involving both hardware and software. Systems need to be designed in a holistic manner so that they are able to provide the desired reliability and minimise unnecessary complexity. The large problem landscape means that there is no one solution that fits all applications of embedded systems. With the primary focus of these mission and safety critical systems being functionality and reliability, there can be conflicts with business needs, and this can introduce pressures to reduce cost at the expense of reliability and functionality. This paper examines the challenges faced by battery powered systems, and then explores at more general problems, and several real-world embedded systems.

Establishing a head and neck unit in a developing country.

PubMed

Aswani, J; Baidoo, K; Otiti, J

2012-06-01

Head and neck cancers pose an especially serious problem in developing countries due to late presentation requiring complex surgical intervention. These countries are faced with many challenges, ranging from insufficient health care staff to problems with peri-operative requirements, diagnostic facilities, chemoradiation services and research funding.These challenges can be addressed through the training of head and neck surgeons and support personnel, the improvement of cancer awareness in local communities, and the establishment of dedicated head and neck institutes which focus on the special needs of head and neck cancer patients.All these changes can best be achieved through collaborative efforts with external partners. The Karl Storz Fellowship in Advanced Head and Neck Cancer, enabling training at the University of Cape Town, South Africa, has served as a springboard towards establishing head and neck services in developing sub-Saharan African countries.

Overview of Medicaid capitation and case-management initiatives

PubMed Central

Freund, Deborah A.; Neuschler, Edward

1986-01-01

Case-management programs have grown in number and in acceptance in the Medicaid program since 1981. In this article, we review their structure and incentives as well as what is known about their impact on cost and use. These programs also have been difficult to implement, posing myriad management challenges for prepaid program managers and State administrators. We highlight the problems in the following areas: eligibility, enrollment, rate setting, and management information systems. PMID:10311923

Embryo Space Colonisation to Overcome the Interstellar Time Distance Bottleneck

NASA Astrophysics Data System (ADS)

Crowl, A.; Hunt, J.; Hein, A. M.

The immense distances to neighbouring star systems pose the single greatest challenge to a true interstellar mission. The challenge is made even greater if the purpose of the mission is scientific in which it is commonly stated that the mission should last no longer than the career of a participating scientist. This imposes speed requirements with a host of well-known problems of propulsion, immense vehicle mass, need for in-space infrastructure, impact hazards, proton flux, and deceleration. If instead the purpose of the interstellar mission is to ensure the survival of humanity by establishing a viable colony using frozen embryos, these many problems are potentially mitigated due to the fact that the speeds can be much slower. Sleeper ships are a suggested low speed alternative, but cosmic ray damage to suspended/frozen humans could place a limit on the acceptable duration of the mission thereby necessitating greater speed with the aforementioned challenges. Near-term solar-sail technology could be sufficient to launch an ESC mission once human ectogenetic technology has matured.

Plant-driven removal of heavy metals from soil: uptake, translocation, tolerance mechanism, challenges, and future perspectives.

PubMed

Thakur, Sveta; Singh, Lakhveer; Wahid, Zularisam Ab; Siddiqui, Muhammad Faisal; Atnaw, Samson Mekbib; Din, Mohd Fadhil Md

2016-04-01

Increasing heavy metal (HM) concentrations in the soil have become a significant problem in the modern industrialized world due to several anthropogenic activities. Heavy metals (HMs) are non-biodegradable and have long biological half lives; thus, once entered in food chain, their concentrations keep on increasing through biomagnification. The increased concentrations of heavy metals ultimately pose threat on human life also. The one captivating solution for this problem is to use green plants for HM removal from soil and render it harmless and reusable. Although this green technology called phytoremediation has many advantages over conventional methods of HM removal from soils, there are also many challenges that need to be addressed before making this technique practically feasible and useful on a large scale. In this review, we discuss the mechanisms of HM uptake, transport, and plant tolerance mechanisms to cope with increased HM concentrations. This review article also comprehensively discusses the advantages, major challenges, and future perspectives of phytoremediation of heavy metals from the soil.

The challenge of treating conduct disorder in low-resourced settings: rap music to the rescue.

PubMed

Evans, Dylan J

2010-12-01

Conduct disorder is one of the most frequent serious childhood problems that present for treatment in community clinic settings. Evidence-based treatments for conduct disorder are intensive and require considerable resources to implement. In low-resourced contexts it is often not feasible to implement evidence-based treatments in their current form, which poses significant challenges for clinicians attempting to treat children in these settings. This article explores these challenges using a case study of the treatment of a young adolescent boy with a short-term multisystem intervention where rap music was employed as a powerful tool to facilitate an empathic connection in therapy and as a projective technique to explore underlying emotional difficulties.

Developing Pre-Service Teachers Understanding of Fractions through Problem Posing

ERIC Educational Resources Information Center

Toluk-Ucar, Zulbiye

2009-01-01

This study investigated the effect of problem posing on the pre-service primary teachers' understanding of fraction concepts enrolled in two different versions of a methods course at a university in Turkey. In the experimental version, problem posing was used as a teaching strategy. At the beginning of the study, the pre-service teachers'…

The Effects of Problem Posing on Student Mathematical Learning: A Meta-Analysis

ERIC Educational Resources Information Center

Rosli, Roslinda; Capraro, Mary Margaret; Capraro, Robert M.

2014-01-01

The purpose of the study was to meta-synthesize research findings on the effectiveness of problem posing and to investigate the factors that might affect the incorporation of problem posing in the teaching and learning of mathematics. The eligibility criteria for inclusion of literature in the meta-analysis was: published between 1989 and 2011,…

Problem-Posing in Education: Transformation of the Practice of the Health Professional.

ERIC Educational Resources Information Center

Casagrande, L. D. R.; Caron-Ruffino, M.; Rodrigues, R. A. P.; Vendrusculo, D. M. S.; Takayanagui, A. M. M.; Zago, M. M. F.; Mendes, M. D.

1998-01-01

Studied the use of a problem-posing model in health education. The model based on the ideas of Paulo Freire is presented. Four innovative experiences of teaching-learning in environmental and occupational health and patient education are reported. Notes that the problem-posing model has the capability to transform health-education practice.…

Prospective Middle School Mathematics Teachers' Knowledge of Linear Graphs in Context of Problem-Posing

ERIC Educational Resources Information Center

Kar, Tugrul

2016-01-01

This study examined prospective middle school mathematics teachers' problem-posing skills by investigating their ability to associate linear graphs with daily life situations. Prospective teachers were given linear graphs and asked to pose problems that could potentially be represented by the graphs. Their answers were analyzed in two stages. In…

Metadata and annotations for multi-scale electrophysiological data.

PubMed

Bower, Mark R; Stead, Matt; Brinkmann, Benjamin H; Dufendach, Kevin; Worrell, Gregory A

2009-01-01

The increasing use of high-frequency (kHz), long-duration (days) intracranial monitoring from multiple electrodes during pre-surgical evaluation for epilepsy produces large amounts of data that are challenging to store and maintain. Descriptive metadata and clinical annotations of these large data sets also pose challenges to simple, often manual, methods of data analysis. The problems of reliable communication of metadata and annotations between programs, the maintenance of the meanings within that information over long time periods, and the flexibility to re-sort data for analysis place differing demands on data structures and algorithms. Solutions to these individual problem domains (communication, storage and analysis) can be configured to provide easy translation and clarity across the domains. The Multi-scale Annotation Format (MAF) provides an integrated metadata and annotation environment that maximizes code reuse, minimizes error probability and encourages future changes by reducing the tendency to over-fit information technology solutions to current problems. An example of a graphical utility for generating and evaluating metadata and annotations for "big data" files is presented.

A cross docking pipeline for improving pose prediction and virtual screening performance

NASA Astrophysics Data System (ADS)

Kumar, Ashutosh; Zhang, Kam Y. J.

2018-01-01

Pose prediction and virtual screening performance of a molecular docking method depend on the choice of protein structures used for docking. Multiple structures for a target protein are often used to take into account the receptor flexibility and problems associated with a single receptor structure. However, the use of multiple receptor structures is computationally expensive when docking a large library of small molecules. Here, we propose a new cross-docking pipeline suitable to dock a large library of molecules while taking advantage of multiple target protein structures. Our method involves the selection of a suitable receptor for each ligand in a screening library utilizing ligand 3D shape similarity with crystallographic ligands. We have prospectively evaluated our method in D3R Grand Challenge 2 and demonstrated that our cross-docking pipeline can achieve similar or better performance than using either single or multiple-receptor structures. Moreover, our method displayed not only decent pose prediction performance but also better virtual screening performance over several other methods.

Challenges of Developing New Classes of NASA Self-Managing Mission

NASA Technical Reports Server (NTRS)

Hinchey, M. G.; Rash, J. I.; Truszkowski, W. F.; Rouff, C. A.; Sterritt, R.

2005-01-01

NASA is proposing increasingly complex missions that will require a high degree of autonomy and autonomicity. These missions pose hereto unforeseen problems and raise issues that have not been well-addressed by the community. Assuring success of such missions will require new software development techniques and tools. This paper discusses some of the challenges that NASA and the rest of the software development community are facing in developing these ever-increasingly complex systems. We give an overview of a proposed NASA mission as well as techniques and tools that are being developed to address autonomic management and the complexity issues inherent in these missions.

Mighty Mathematicians: Using Problem Posing and Problem Solving to Develop Mathematical Power

ERIC Educational Resources Information Center

McGatha, Maggie B.; Sheffield, Linda J.

2006-01-01

This article describes a year-long professional development institute combined with a summer camp for students. Both were designed to help teachers and students develop their problem-solving and problem-posing abilities.

An Analysis of Problem-Posing Tasks in Chinese and US Elementary Mathematics Textbooks

ERIC Educational Resources Information Center

Cai, Jinfa; Jiang, Chunlian

2017-01-01

This paper reports on 2 studies that examine how mathematical problem posing is integrated in Chinese and US elementary mathematics textbooks. Study 1 involved a historical analysis of the problem-posing (PP) tasks in 3 editions of the most widely used elementary mathematics textbook series published by People's Education Press in China over 3…

Fraction Multiplication and Division Word Problems Posed by Different Years of Pre-Service Elementary Mathematics Teachers

ERIC Educational Resources Information Center

Aydogdu Iskenderoglu, Tuba

2018-01-01

It is important for pre-service teachers to know the conceptual difficulties they have experienced regarding the concepts of multiplication and division in fractions and problem posing is a way to learn these conceptual difficulties. Problem posing is a synthetic activity that fundamentally has multiple answers. The purpose of this study is to…

Generalizability Theory Research on Developing a Scoring Rubric to Assess Primary School Students' Problem Posing Skills

ERIC Educational Resources Information Center

Cankoy, Osman; Özder, Hasan

2017-01-01

The aim of this study is to develop a scoring rubric to assess primary school students' problem posing skills. The rubric including five dimensions namely solvability, reasonability, mathematical structure, context and language was used. The raters scored the students' problem posing skills both with and without the scoring rubric to test the…

An Investigation of Relationships between Students' Mathematical Problem-Posing Abilities and Their Mathematical Content Knowledge

ERIC Educational Resources Information Center

Van Harpen, Xianwei Y.; Presmeg, Norma C.

2013-01-01

The importance of students' problem-posing abilities in mathematics has been emphasized in the K-12 curricula in the USA and China. There are claims that problem-posing activities are helpful in developing creative approaches to mathematics. At the same time, there are also claims that students' mathematical content knowledge could be highly…

An Investigation of Eighth Grade Students' Problem Posing Skills (Turkey Sample)

ERIC Educational Resources Information Center

Arikan, Elif Esra; Ünal, Hasan

2015-01-01

To pose a problem refers to the creative activity for mathematics education. The purpose of the study was to explore the eighth grade students' problem posing ability. Three learning domains such as requiring four operations, fractions and geometry were chosen for this reason. There were two classes which were coded as class A and class B. Class A…

Mathematical Creative Process Wallas Model in Students Problem Posing with Lesson Study Approach

ERIC Educational Resources Information Center

Nuha, Muhammad 'Azmi; Waluya, S. B.; Junaedi, Iwan

2018-01-01

Creative thinking is very important in the modern era so that it should be improved by doing efforts such as making a lesson that train students to pose their own problems. The purposes of this research are (1) to give an initial description of students about mathematical creative thinking level in Problem Posing Model with Lesson Study approach…

Improving extreme-scale problem solving: assessing electronic brainstorming effectiveness in an industrial setting.

PubMed

Dornburg, Courtney C; Stevens, Susan M; Hendrickson, Stacey M L; Davidson, George S

2009-08-01

An experiment was conducted to compare the effectiveness of individual versus group electronic brainstorming to address difficult, real-world challenges. Although industrial reliance on electronic communications has become ubiquitous, empirical and theoretical understanding of the bounds of its effectiveness have been limited. Previous research using short-term laboratory experiments have engaged small groups of students in answering questions irrelevant to an industrial setting. The present experiment extends current findings beyond the laboratory to larger groups of real-world employees addressing organization-relevant challenges during the course of 4 days. Employees and contractors at a national laboratory participated, either in a group setting or individually, in an electronic brainstorm to pose solutions to a real-world problem. The data demonstrate that (for this design) individuals perform at least as well as groups in producing quantity of electronic ideas, regardless of brainstorming duration. However, when judged with respect to quality along three dimensions (originality, feasibility, and effectiveness), the individuals significantly (p < .05) outperformed the group. When quality is used to benchmark success, these data indicate that work-relevant challenges are better solved by aggregating electronic individual responses rather than by electronically convening a group. This research suggests that industrial reliance on electronic problem-solving groups should be tempered, and large nominal groups may be more appropriate corporate problem-solving vehicles.

Problem Posing with Realistic Mathematics Education Approach in Geometry Learning

NASA Astrophysics Data System (ADS)

Mahendra, R.; Slamet, I.; Budiyono

2017-09-01

One of the difficulties of students in the learning of geometry is on the subject of plane that requires students to understand the abstract matter. The aim of this research is to determine the effect of Problem Posing learning model with Realistic Mathematics Education Approach in geometry learning. This quasi experimental research was conducted in one of the junior high schools in Karanganyar, Indonesia. The sample was taken using stratified cluster random sampling technique. The results of this research indicate that the model of Problem Posing learning with Realistic Mathematics Education Approach can improve students’ conceptual understanding significantly in geometry learning especially on plane topics. It is because students on the application of Problem Posing with Realistic Mathematics Education Approach are become to be active in constructing their knowledge, proposing, and problem solving in realistic, so it easier for students to understand concepts and solve the problems. Therefore, the model of Problem Posing learning with Realistic Mathematics Education Approach is appropriately applied in mathematics learning especially on geometry material. Furthermore, the impact can improve student achievement.

Gambling involvement and increased risk of gambling problems.

PubMed

Phillips, James G; Ogeil, Rowan; Chow, Yang-Wai; Blaszczynski, Alex

2013-12-01

The opportunity to gamble has undergone rapid expansion with technology allowing for access to gambling products 24 h a day. This increased online availability challenges governments' abilities to restrict access to gambling. Indeed, the ready access to multiple forms of gambling may potentially contribute to impaired control over urges for problem gamblers. The present study considered whether problem gamblers manifested a tendency to engage in multiple forms of gambling and identified forms of gambling which were more strongly related to problem gambling. In reanalyses of two surveys (Sample 1, N = 464, Sample 2, N = 1141), significant relationships accounting for between 11.3 and 13.5% of the variance were found between the numbers of forms of gambling accessed and degree of problem. Participation in online poker, playing cards and sports wagering were linked to problem gambling. Access to multiple forms of gambling may pose difficulties for the tracking and control of gambling.

The dumbest experiment in space. [problems in laboratory apparatus adaption to space environment

NASA Technical Reports Server (NTRS)

Prouty, C. R.

1981-01-01

A simple conceptual experiment is used to illustrate (1) the fundamentals of performing an experiment, including the theoretical concept, the experiment design, the performance of the experiment, and the recording of observations; (2) the increasing challenges posed by performance of the same experiment in a location remote from the experimenter, such as additional planning and equipment and their associated cost increases; and (3) the significant growth of difficulties to be overcome when the simple experiment is performed in a highly restrictive environment, such as a spacecraft in orbit, with someone else remotely operating the experiment. It is shown that performing an experiment in the remote, hostile environment of space will pose difficulties equaling or exceeding those of the experiment itself, entailing mastery of a widening range of disciplines.

Air-Sea Battle And The U.S. Rebalance To The Pacific

DTIC Science & Technology

2016-03-28

based on capability, capacity and intent. Other potential adversaries such as Iran and Russia certainly pose a challenge to U.S. power projection but...such as China, Iran , and Russia. It is, therefore, necessary to understand the problem before developing an operational concept to solve it. While...the People’s Republic of China (PRC) and the Islamic Republic of Iran .20 Joint Concept for Access and Maneuver in the Global Commons (JAM-GC

Designing Adaptive Low Dissipative High Order Schemes

NASA Technical Reports Server (NTRS)

Yee, H. C.; Sjoegreen, B.; Parks, John W. (Technical Monitor)

2002-01-01

Proper control of the numerical dissipation/filter to accurately resolve all relevant multiscales of complex flow problems while still maintaining nonlinear stability and efficiency for long-time numerical integrations poses a great challenge to the design of numerical methods. The required type and amount of numerical dissipation/filter are not only physical problem dependent, but also vary from one flow region to another. This is particularly true for unsteady high-speed shock/shear/boundary-layer/turbulence/acoustics interactions and/or combustion problems since the dynamics of the nonlinear effect of these flows are not well-understood. Even with extensive grid refinement, it is of paramount importance to have proper control on the type and amount of numerical dissipation/filter in regions where it is needed.

Trends and Challenges in Smart Healthcare Research: A Journey from Data to Wisdom

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solanas, Agusti; Fran, Casino; Batista, Edgar

Smart Healthcare is a relatively new context-aware healthcare paradigm influenced by several fields of knowledge, namely medical informatics, communications and electronics, bioengineering, ethics and so on. Thus, many challenging problems are related to smart healthcare but in many cases they are explored individually in their respective fields and, as a result, they are not always known by the smart healthcare research community working in more specific domains. The aim of this article is to identify some of the most relevant trends and research lines that are going to affect the smart healthcare field in the years to come. To domore » so, the article considers a systematic approach that classifies the identified research trends and problems according to their appearance within the data life cycle, this is, from the data gathering in the physical layer (lowest level) until their final use in the application layer (highest level). By identifying and classifying those research trends and challenges, we help to pose questions that the smart healthcare community will need to address. Consequently, we set a common ground to explore important problems in the field, which will have significant impact in the years to come.« less

Problem Posing and Solving with Mathematical Modeling

ERIC Educational Resources Information Center

English, Lyn D.; Fox, Jillian L.; Watters, James J.

2005-01-01

Mathematical modeling is explored as both problem posing and problem solving from two perspectives, that of the child and the teacher. Mathematical modeling provides rich learning experiences for elementary school children and their teachers.

‘SHE'S MY SISTER-IN-LAW, MY VISITOR, MY FRIEND’ – CHALLENGES OF STAFF IDENTITY IN HOME FOLLOW-UP IN AN HIV TRIAL IN WESTERN KENYA

PubMed Central

Madiega, Philister Adhiambo; Jones, Gemma; Prince, Ruth Jane; Geissler, Paul Wenzel

2013-01-01

Identities ascribed to research staff in face-to-face encounters with participants have been raised as key ethical challenge in transnational health research. ‘Misattributed’ identities that do not just deviate from researchers' self-image, but obscure unequivocal aspects of researcher identity – e.g. that they are researchers – are a case of such ethical problem. Yet, the reasonable expectation of unconcealed identity can conflict with another ethical premise: confidentiality; this poses challenges to staff visiting participants at home. We explore these around a case study of ‘follow-up’ staff, observed during an ethnographic study of a Kenyan HIV ‘trial community’, which included participant observation, conversations, and interviews with staff (n = 79) and participants (n = 89). We found that because of the need to maintain confidentiality and because of some suspicions towards researchers, research staff drew upon alternative identities – presenting themselves to non-participants as relatives or friends, rather than as researchers. Several staff experienced this as necessary but uncomfortable. Simultaneously, staff and participants forged close relations in line with their fictional identities, which however also posed challenges because they entailed personal responsibilities that were difficult to live up to, due to limited resources, and the trial's limited duration. Similar challenges may arise in transnational HIV treatment programmes and should be explored further in that context. PMID:23521821

Current Status of Mycotoxin Analysis: A Critical Review.

PubMed

Shephard, Gordon S

2016-07-01

It is over 50 years since the discovery of aflatoxins focused the attention of food safety specialists on fungal toxins in the feed and food supply. Since then, analysis of this important group of natural contaminants has advanced in parallel with general developments in analytical science, and current MS methods are capable of simultaneously analyzing hundreds of compounds, including mycotoxins, pesticides, and drugs. This profusion of data may advance our understanding of human exposure, yet constitutes an interpretive challenge to toxicologists and food safety regulators. Despite these advances in analytical science, the basic problem of the extreme heterogeneity of mycotoxin contamination, although now well understood, cannot be circumvented. The real health challenges posed by mycotoxin exposure occur in the developing world, especially among small-scale and subsistence farmers. Addressing these problems requires innovative approaches in which analytical science must also play a role in providing suitable out-of-laboratory analytical techniques.

The Species Problem in Myxomycetes Revisited.

PubMed

Walker, Laura M; Stephenson, Steven L

2016-08-01

Species identification in the myxomycetes (plasmodial slime molds or myxogastrids) poses particular challenges to researchers as a result of their morphological plasticity and frequent alteration between sexual and asexual life strategies. Traditionally, myxomycete morphology has been used as the primary method of species delimitation. However, with the increasing availability of genetic information, traditional myxomycete taxonomy is being increasingly challenged, and new hypotheses continue to emerge. Due to conflicts that sometimes occur between traditional and more modern species concepts that are based largely on molecular data, there is a pressing need to revisit the discussion surrounding the species concept used for myxomycetes. Biological diversity is being increasingly studied with molecular methods and data accumulates at ever-faster rates, making resolution of this matter urgent. In this review, currently used and potentially useful species concepts (biological, morphological, phylogenetic and ecological) are reviewed, and an integrated approach to resolve the myxomycete species problem is discussed. Copyright © 2016 Elsevier GmbH. All rights reserved.

Problem-posing in education: transformation of the practice of the health professional.

PubMed

Casagrande, L D; Caron-Ruffino, M; Rodrigues, R A; Vendrúsculo, D M; Takayanagui, A M; Zago, M M; Mendes, M D

1998-02-01

This study was developed by a group of professionals from different areas (nurses and educators) concerned with health education. It proposes the use of a problem-posing model for the transformation of professional practice. The concept and functions of the model and their relationships with the educative practice of health professionals are discussed. The model of problem-posing education is presented (compared to traditional, "banking" education), and four innovative experiences of teaching-learning are reported based on this model. These experiences, carried out in areas of environmental and occupational health and patient education have shown the applicability of the problem-posing model to the practice of the health professional, allowing transformation.

[Problem-posing as a nutritional education strategy with obese teenagers].

PubMed

Rodrigues, Erika Marafon; Boog, Maria Cristina Faber

2006-05-01

Obesity is a public health issue with relevant social determinants in its etiology and where interventions with teenagers encounter complex biopsychological conditions. This study evaluated intervention in nutritional education through a problem-posing approach with 22 obese teenagers, treated collectively and individually for eight months. Speech acts were collected through the use of word cards, observer recording, and tape-recording. The study adopted a qualitative methodology, and the approach involved content analysis. Problem-posing facilitated changes in eating behavior, triggering reflections on nutritional practices, family circumstances, social stigma, interaction with health professionals, and religion. Teenagers under individual care posed problems more effectively in relation to eating, while those under collective care posed problems in relation to family and psychological issues, with effective qualitative eating changes in both groups. The intervention helped teenagers understand their life history and determinants of eating behaviors, spontaneously implementing eating changes and making them aware of possibilities for maintaining the new practices and autonomously exercising their role as protagonists in their own health care.

Access to hospitals in the wake of terrorism: challenges and needs for maintaining public confidence.

PubMed

May, Thomas; Aulisio, Mark P

2006-01-01

The problem of surge capacity in the wake of a terror-related emergency has lead to a number of interesting proposals designed to mitigate the effects of crowds as well as deficiencies in patient care capacities. The most controversial of these is a proposal to close hospital doors in the wake of a mass casualty terror event. However, several specific challenges posed by mass casualty events make closing hospitals doors undesirable. These include the need for efficient movement of resources, maintenance of social order, and providing the moral reassurance needed by the general public in times of crisis. Importantly, these challenges are related to features of terrorist events that distinguish such events from circumstances of "normal" surge that might result in, for example, closure of emergency rooms.

Cluster randomization and political philosophy.

PubMed

Chwang, Eric

2012-11-01

In this paper, I will argue that, while the ethical issues raised by cluster randomization can be challenging, they are not new. My thesis divides neatly into two parts. In the first, easier part I argue that many of the ethical challenges posed by cluster randomized human subjects research are clearly present in other types of human subjects research, and so are not novel. In the second, more difficult part I discuss the thorniest ethical challenge for cluster randomized research--cases where consent is genuinely impractical to obtain. I argue that once again these cases require no new analytic insight; instead, we should look to political philosophy for guidance. In other words, the most serious ethical problem that arises in cluster randomized research also arises in political philosophy. © 2011 Blackwell Publishing Ltd.

Fostering Mathematical Creativity through Problem Posing and Modeling Using Dynamic Geometry: Viviani's Problem in the Classroom

ERIC Educational Resources Information Center

Contreras, José N.

2013-01-01

This paper discusses a classroom experience in which a group of prospective secondary mathematics teachers were asked to create, cooperatively (in class) and individually, problems related to Viviani's problem using a problem-posing framework. When appropriate, students used Sketchpad to explore the problem to better understand its attributes…

Investigating Mathematics Teachers Candidates' Knowledge about Problem Solving Strategies through Problem Posing

ERIC Educational Resources Information Center

Ünlü, Melihan

2017-01-01

The aim of the study was to determine mathematics teacher candidates' knowledge about problem solving strategies through problem posing. This qualitative research was conducted with 95 mathematics teacher candidates studying at education faculty of a public university during the first term of the 2015-2016 academic year in Turkey. Problem Posing…

On the stabilizing role of species diffusion in chemical enhanced oil recovery

NASA Astrophysics Data System (ADS)

Daripa, Prabir; Gin, Craig

2015-11-01

In this talk, the speaker will discuss a problem on the stability analysis related to the effect of species diffusion on stabilization of fingering in a Hele-Shaw model of chemical enhanced oil recovery. The formulation of the problem is motivated by a specific design principle of the immiscible interfaces in the hope that this will lead to significant stabilization of interfacial instabilities, there by improving oil recovery in the context of porous media flow. Testing the merits of this hypothesis poses some challenges which will be discussed along with some numerical results based on current formulation of this problem. Several open problems in this context will be discussed. This work is currently under progress. Supported by the grant NPRP 08-777-1-141 from the Qatar National Research Fund (a member of The Qatar Foundation).

Supporting ontology-based keyword search over medical databases.

PubMed

Kementsietsidis, Anastasios; Lim, Lipyeow; Wang, Min

2008-11-06

The proliferation of medical terms poses a number of challenges in the sharing of medical information among different stakeholders. Ontologies are commonly used to establish relationships between different terms, yet their role in querying has not been investigated in detail. In this paper, we study the problem of supporting ontology-based keyword search queries on a database of electronic medical records. We present several approaches to support this type of queries, study the advantages and limitations of each approach, and summarize the lessons learned as best practices.

Significant Figures in Measurements with Uncertainty: A Working Criterion

NASA Astrophysics Data System (ADS)

Vilchis, Abraham

2017-03-01

Generally speaking, students have difficulty reporting out measurements and estimates of quantities used in the laboratory, and with handling the significant figures associated with them. When required to make calculation involving quantities with different numbers of significant figures, they have difficulty in assigning the corresponding digits to the final result. When in addition, the quantities have uncertainty, the operations entailed pose an even greater challenge. The article advocates for some working rules for students (and teachers) in an effort to combat this problem.

Ethical relativism in a multicultural society.

PubMed

Macklin, Ruth

1998-03-01

The multicultural composition of the United States can pose problems for physicians and patients who come from diverse backgrounds. Although respect for cultural diversity mandates tolerance of the beliefs and practices of others, in some situations excessive tolerance can produce harm to patients. Careful analysis is needed to determine which values are culturally relative and which rest on an underlying universal ethical principle. A conception of justice as equality challenges the notion that it is always necessary to respect all of the beliefs and practices of every cultural group.

The role of synergies within generative models of action execution and recognition: A computational perspective. Comment on "Grasping synergies: A motor-control approach to the mirror neuron mechanism" by A. D'Ausilio et al.

NASA Astrophysics Data System (ADS)

Pezzulo, Giovanni; Donnarumma, Francesco; Iodice, Pierpaolo; Prevete, Roberto; Dindo, Haris

2015-03-01

Controlling the body - given its huge number of degrees of freedom - poses severe computational challenges. Mounting evidence suggests that the brain alleviates this problem by exploiting "synergies", or patterns of muscle activities (and/or movement dynamics and kinematics) that can be combined to control action, rather than controlling individual muscles of joints [1-10].

Privacy and Access Control for IHE-Based Systems

NASA Astrophysics Data System (ADS)

Katt, Basel; Breu, Ruth; Hafner, Micahel; Schabetsberger, Thomas; Mair, Richard; Wozak, Florian

Electronic Health Record (EHR) is the heart element of any e-health system, which aims at improving the quality and efficiency of healthcare through the use of information and communication technologies. The sensitivity of the data contained in the health record poses a great challenge to security. In this paper we propose a security architecture for EHR systems that are conform with IHE profiles. In this architecture we are tackling the problems of access control and privacy. Furthermore, a prototypical implementation of the proposed model is presented.

Technology-based Interventions for Preventing and Treating Substance Use Among Youth

PubMed Central

Marsch, Lisa A.; Borodovsky, Jacob T.

2017-01-01

Summary Preventing or mitigating substance use among youth generally involves three different intervention frameworks: universal prevention, selective prevention, and treatment. Each of these levels of intervention poses unique therapeutic and implementation challenges. Technology-based interventions provide solutions to many of these problems by delivering evidence-based interventions in a consistent and cost-effective manner. This article summarizes the current state of the science of technology-based interventions for preventing substance use initiation and mitigating substance use and associated consequences among youth. PMID:27613350

Challenges in the automated classification of variable stars in large databases

NASA Astrophysics Data System (ADS)

Graham, Matthew; Drake, Andrew; Djorgovski, S. G.; Mahabal, Ashish; Donalek, Ciro

2017-09-01

With ever-increasing numbers of astrophysical transient surveys, new facilities and archives of astronomical time series, time domain astronomy is emerging as a mainstream discipline. However, the sheer volume of data alone - hundreds of observations for hundreds of millions of sources - necessitates advanced statistical and machine learning methodologies for scientific discovery: characterization, categorization, and classification. Whilst these techniques are slowly entering the astronomer's toolkit, their application to astronomical problems is not without its issues. In this paper, we will review some of the challenges posed by trying to identify variable stars in large data collections, including appropriate feature representations, dealing with uncertainties, establishing ground truths, and simple discrete classes.

Evidence-based librarianship: searching for the needed EBL evidence.

PubMed

Eldredge, J D

2000-01-01

This paper discusses the challenges of finding evidence needed to implement Evidence-Based Librarianship (EBL). Focusing first on database coverage for three health sciences librarianship journals, the article examines the information contents of different databases. Strategies are needed to search for relevant evidence in the library literature via these databases, and the problems associated with searching the grey literature of librarianship. Database coverage, plausible search strategies, and the grey literature of library science all pose challenges to finding the needed research evidence for practicing EBL. Health sciences librarians need to ensure that systems are designed that can track and provide access to needed research evidence to support Evidence-Based Librarianship (EBL).

The challenges of reintegration for service members and their families.

PubMed

Danish, Steven J; Antonides, Bradley J

2013-10-01

The ongoing wars in Afghanistan and Iraq have posed a number of reintegration challenges to service members. Much of the research focuses on those service members experiencing psychological problems and being treated at the VA. In this article, we contend that much of the distress service members experience occurs following deployment and is a consequence of the difficulties encountered during their efforts to successfully reintegrate into their families and communities. We propose a new conceptual framework for intervening in this reintegration distress that is psycho-educational in nature as well as a new delivery model for providing such services. An example of this new intervention framework is presented. © 2013 American Orthopsychiatric Association.

Six Challenges for Ethical Conduct in Science.

PubMed

Niemi, Petteri

2016-08-01

The realities of human agency and decision making pose serious challenges for research ethics. This article explores six major challenges that require more attention in the ethics education of students and scientists and in the research on ethical conduct in science. The first of them is the routinization of action, which makes the detection of ethical issues difficult. The social governance of action creates ethical problems related to power. The heuristic nature of human decision making implies the risk of ethical bias. The moral disengagement mechanisms represent a human tendency to evade personal responsibility. The greatest challenge of all might be the situational variation in people's ethical behaviour. Even minor situational factors have a surprisingly strong influence on our actions. Furthermore, finally, the nature of ethics itself also causes problems: instead of clear answers, we receive a multitude of theories and intuitions that may sometimes be contradictory. All these features of action and ethics represent significant risks for ethical conduct in science. I claim that they have to be managed within the everyday practices of science and addressed explicitly in research ethics education. I analyse them and suggest some ways in which their risks can be alleviated.

A Problem-Solving Conceptual Framework and Its Implications in Designing Problem-Posing Tasks

ERIC Educational Resources Information Center

Singer, Florence Mihaela; Voica, Cristian

2013-01-01

The links between the mathematical and cognitive models that interact during problem solving are explored with the purpose of developing a reference framework for designing problem-posing tasks. When the process of solving is a successful one, a solver successively changes his/her cognitive stances related to the problem via transformations that…

Opportunities to Pose Problems Using Digital Technology in Problem Solving Environments

ERIC Educational Resources Information Center

Aguilar-Magallón, Daniel Aurelio; Fernández, Willliam Enrique Poveda

2017-01-01

This article reports and analyzes different types of problems that nine students in a Master's Program in Mathematics Education posed during a course on problem solving. What opportunities (affordances) can a dynamic geometry system (GeoGebra) offer to allow in-service and in-training teachers to formulate and solve problems, and what type of…

Communicating Climate Change: the Problem of Knowing and Doing.

NASA Astrophysics Data System (ADS)

Wildcat, D.

2008-12-01

The challenge of global warming and climate change may illustrate better than any recent phenomenon that quite independent of the science associated with our assessment, modeling, mitigation strategies and adaptation to the multiple complex processes that characterize this phenomenon, our greatest challenge resides in creating systems where knowledge can be usefully communicated to the general public. Knowledge transfer will pose significant challenges when addressing a topic that often leaves the ill-informed and non-scientist overwhelmed with pieces of information and paralyzed with a sense that there is nothing to be done to address this global problem. This communication problem is very acute in North American indigenous communities where a first-hand, on-the-ground, experience of climate change is indisputable, but where the charts, graphs and sophisticated models presented by scientists are treated with suspicion and often not explained very well. This presentation will discuss the efforts of the American Indian and Alaska Native Climate Change Working Group to prepare future generations of AI/AN geoscience professionals, educators, and a geoscience literate AI/AN workforce, while insuring that our Indigenous tribal knowledges of land- and sea-scapes, and climates are valued, used and incorporated into our tribal exercise of geoscience education and research. The Working Group's efforts are already suggesting the communication problem for Indigenous communities will best be solved by 'growing' our own culturally competent Indigenous geoscience professionals.

Evaluating Web accessibility at different processing phases

NASA Astrophysics Data System (ADS)

Fernandes, N.; Lopes, R.; Carriço, L.

2012-09-01

Modern Web sites use several techniques (e.g. DOM manipulation) that allow for the injection of new content into their Web pages (e.g. AJAX), as well as manipulation of the HTML DOM tree. This has the consequence that the Web pages that are presented to users (i.e. after browser processing) are different from the original structure and content that is transmitted through HTTP communication (i.e. after browser processing). This poses a series of challenges for Web accessibility evaluation, especially on automated evaluation software. This article details an experimental study designed to understand the differences posed by accessibility evaluation after Web browser processing. We implemented a Javascript-based evaluator, QualWeb, that can perform WCAG 2.0 based accessibility evaluations in the two phases of browser processing. Our study shows that, in fact, there are considerable differences between the HTML DOM trees in both phases, which have the consequence of having distinct evaluation results. We discuss the impact of these results in the light of the potential problems that these differences can pose to designers and developers that use accessibility evaluators that function before browser processing.

Robust kernel representation with statistical local features for face recognition.

PubMed

Yang, Meng; Zhang, Lei; Shiu, Simon Chi-Keung; Zhang, David

2013-06-01

Factors such as misalignment, pose variation, and occlusion make robust face recognition a difficult problem. It is known that statistical features such as local binary pattern are effective for local feature extraction, whereas the recently proposed sparse or collaborative representation-based classification has shown interesting results in robust face recognition. In this paper, we propose a novel robust kernel representation model with statistical local features (SLF) for robust face recognition. Initially, multipartition max pooling is used to enhance the invariance of SLF to image registration error. Then, a kernel-based representation model is proposed to fully exploit the discrimination information embedded in the SLF, and robust regression is adopted to effectively handle the occlusion in face images. Extensive experiments are conducted on benchmark face databases, including extended Yale B, AR (A. Martinez and R. Benavente), multiple pose, illumination, and expression (multi-PIE), facial recognition technology (FERET), face recognition grand challenge (FRGC), and labeled faces in the wild (LFW), which have different variations of lighting, expression, pose, and occlusions, demonstrating the promising performance of the proposed method.

The problem and promise of scale dependency in community phylogenetics.

PubMed

Swenson, Nathan G; Enquist, Brian J; Pither, Jason; Thompson, Jill; Zimmerman, Jess K

2006-10-01

The problem of scale dependency is widespread in investigations of ecological communities. Null model investigations of community assembly exemplify the challenges involved because they typically include subjectively defined "regional species pools." The burgeoning field of community phylogenetics appears poised to face similar challenges. Our objective is to quantify the scope of the problem of scale dependency by comparing the phylogenetic structure of assemblages across contrasting geographic and taxonomic scales. We conduct phylogenetic analyses on communities within three tropical forests, and perform a sensitivity analysis with respect to two scaleable inputs: taxonomy and species pool size. We show that (1) estimates of phylogenetic overdispersion within local assemblages depend strongly on the taxonomic makeup of the local assemblage and (2) comparing the phylogenetic structure of a local assemblage to a species pool drawn from increasingly larger geographic scales results in an increased signal of phylogenetic clustering. We argue that, rather than posing a problem, "scale sensitivities" are likely to reveal general patterns of diversity that could help identify critical scales at which local or regional influences gain primacy for the structuring of communities. In this way, community phylogenetics promises to fill an important gap in community ecology and biogeography research.

Tracking the When, Where, and With Whom of Alcohol Use

PubMed Central

Freisthler, Bridget; Lipperman-Kreda, Sharon; Bersamin, Melina; Gruenewald, Paul J.

2014-01-01

Prevention researchers have found that drinking in different contexts is related to different alcohol problems. Where and with whom people drink affects the types of alcohol-related problems they experience. Consequently, identifying those contexts that result in the greatest number of problems provides a novel opportunity to target new prevention efforts aimed at those contexts. However, identifying these contexts poses methodological challenges to prevention research. To overcome these challenges, researchers need tools that allow them to gather detailed information about when and where people choose to drink and how contextual factors influence drinking risks. New data collection and analysis techniques, such as activity-space analysis, which examines movement through different contexts, and ecological momentary assessment, which captures microlevel contextual changes as individuals move through their days, can advance the field of alcohol studies by providing detailed information on the use of drinking contexts, particularly when combined. Data acquired through these methods allow researchers to better identify those contexts where and conditions under which drinking and problems related to drinking occur. Use of these methods will allow prevention practitioners to target prevention efforts to those contexts that place most drinkers at risk and tailor prevention efforts to each context for specific outcomes. PMID:26258998

Security Planning and Policies to Meet the Challenges of Climate Change

DTIC Science & Technology

2010-07-01

Security Climate change poses challenges to societies and governments that go far beyond the alteration of our environment. The physical impacts of...capacity of governments to respond. In this sense, the growing likelihood of events such as mass migrations, crop failures, economic shocks, public...riots and violence, floods and other natural disasters, widespread epidemics, and competition for resources pose serious challenges for governments and

Prospective evaluation of shape similarity based pose prediction method in D3R Grand Challenge 2015

NASA Astrophysics Data System (ADS)

Kumar, Ashutosh; Zhang, Kam Y. J.

2016-09-01

Evaluation of ligand three-dimensional (3D) shape similarity is one of the commonly used approaches to identify ligands similar to one or more known active compounds from a library of small molecules. Apart from using ligand shape similarity as a virtual screening tool, its role in pose prediction and pose scoring has also been reported. We have recently developed a method that utilizes ligand 3D shape similarity with known crystallographic ligands to predict binding poses of query ligands. Here, we report the prospective evaluation of our pose prediction method through the participation in drug design data resource (D3R) Grand Challenge 2015. Our pose prediction method was used to predict binding poses of heat shock protein 90 (HSP90) and mitogen activated protein kinase kinase kinase kinase (MAP4K4) ligands and it was able to predict the pose within 2 Å root mean square deviation (RMSD) either as the top pose or among the best of five poses in a majority of cases. Specifically for HSP90 protein, a median RMSD of 0.73 and 0.68 Å was obtained for the top and the best of five predictions respectively. For MAP4K4 target, although the median RMSD for our top prediction was only 2.87 Å but the median RMSD of 1.67 Å for the best of five predictions was well within the limit for successful prediction. Furthermore, the performance of our pose prediction method for HSP90 and MAP4K4 ligands was always among the top five groups. Particularly, for MAP4K4 protein our pose prediction method was ranked number one both in terms of mean and median RMSD when the best of five predictions were considered. Overall, our D3R Grand Challenge 2015 results demonstrated that ligand 3D shape similarity with the crystal ligand is sufficient to predict binding poses of new ligands with acceptable accuracy.

A direct method for nonlinear ill-posed problems

NASA Astrophysics Data System (ADS)

Lakhal, A.

2018-02-01

We propose a direct method for solving nonlinear ill-posed problems in Banach-spaces. The method is based on a stable inversion formula we explicitly compute by applying techniques for analytic functions. Furthermore, we investigate the convergence and stability of the method and prove that the derived noniterative algorithm is a regularization. The inversion formula provides a systematic sensitivity analysis. The approach is applicable to a wide range of nonlinear ill-posed problems. We test the algorithm on a nonlinear problem of travel-time inversion in seismic tomography. Numerical results illustrate the robustness and efficiency of the algorithm.

A deep learning approach for pose estimation from volumetric OCT data.

PubMed

Gessert, Nils; Schlüter, Matthias; Schlaefer, Alexander

2018-05-01

Tracking the pose of instruments is a central problem in image-guided surgery. For microscopic scenarios, optical coherence tomography (OCT) is increasingly used as an imaging modality. OCT is suitable for accurate pose estimation due to its micrometer range resolution and volumetric field of view. However, OCT image processing is challenging due to speckle noise and reflection artifacts in addition to the images' 3D nature. We address pose estimation from OCT volume data with a new deep learning-based tracking framework. For this purpose, we design a new 3D convolutional neural network (CNN) architecture to directly predict the 6D pose of a small marker geometry from OCT volumes. We use a hexapod robot to automatically acquire labeled data points which we use to train 3D CNN architectures for multi-output regression. We use this setup to provide an in-depth analysis on deep learning-based pose estimation from volumes. Specifically, we demonstrate that exploiting volume information for pose estimation yields higher accuracy than relying on 2D representations with depth information. Supporting this observation, we provide quantitative and qualitative results that 3D CNNs effectively exploit the depth structure of marker objects. Regarding the deep learning aspect, we present efficient design principles for 3D CNNs, making use of insights from the 2D deep learning community. In particular, we present Inception3D as a new architecture which performs best for our application. We show that our deep learning approach reaches errors at our ground-truth label's resolution. We achieve a mean average error of 14.89 ± 9.3 µm and 0.096 ± 0.072° for position and orientation learning, respectively. Copyright © 2018 Elsevier B.V. All rights reserved.

Combining in silico and in cerebro approaches for virtual screening and pose prediction in SAMPL4.

PubMed

Voet, Arnout R D; Kumar, Ashutosh; Berenger, Francois; Zhang, Kam Y J

2014-04-01

The SAMPL challenges provide an ideal opportunity for unbiased evaluation and comparison of different approaches used in computational drug design. During the fourth round of this SAMPL challenge, we participated in the virtual screening and binding pose prediction on inhibitors targeting the HIV-1 integrase enzyme. For virtual screening, we used well known and widely used in silico methods combined with personal in cerebro insights and experience. Regular docking only performed slightly better than random selection, but the performance was significantly improved upon incorporation of additional filters based on pharmacophore queries and electrostatic similarities. The best performance was achieved when logical selection was added. For the pose prediction, we utilized a similar consensus approach that amalgamated the results of the Glide-XP docking with structural knowledge and rescoring. The pose prediction results revealed that docking displayed reasonable performance in predicting the binding poses. However, prediction performance can be improved utilizing scientific experience and rescoring approaches. In both the virtual screening and pose prediction challenges, the top performance was achieved by our approaches. Here we describe the methods and strategies used in our approaches and discuss the rationale of their performances.

Combining in silico and in cerebro approaches for virtual screening and pose prediction in SAMPL4

NASA Astrophysics Data System (ADS)

Voet, Arnout R. D.; Kumar, Ashutosh; Berenger, Francois; Zhang, Kam Y. J.

2014-04-01

The SAMPL challenges provide an ideal opportunity for unbiased evaluation and comparison of different approaches used in computational drug design. During the fourth round of this SAMPL challenge, we participated in the virtual screening and binding pose prediction on inhibitors targeting the HIV-1 integrase enzyme. For virtual screening, we used well known and widely used in silico methods combined with personal in cerebro insights and experience. Regular docking only performed slightly better than random selection, but the performance was significantly improved upon incorporation of additional filters based on pharmacophore queries and electrostatic similarities. The best performance was achieved when logical selection was added. For the pose prediction, we utilized a similar consensus approach that amalgamated the results of the Glide-XP docking with structural knowledge and rescoring. The pose prediction results revealed that docking displayed reasonable performance in predicting the binding poses. However, prediction performance can be improved utilizing scientific experience and rescoring approaches. In both the virtual screening and pose prediction challenges, the top performance was achieved by our approaches. Here we describe the methods and strategies used in our approaches and discuss the rationale of their performances.

Open Collaboration: A Problem Solving Strategy That Is Redefining NASA's Innovative Spirit

NASA Technical Reports Server (NTRS)

Rando, Cynthia M.; Fogarty, Jennifer A.; Richard, Elizabeth E.; Davis, Jeffrey R.

2011-01-01

In 2010, NASA?s Space Life Sciences Directorate announced the successful results from pilot experiments with open innovation methodologies. Specifically, utilization of internet based external crowd sourcing platforms to solve challenging problems in human health and performance related to the future of spaceflight. The follow-up to this success was an internal crowd sourcing pilot program entitled NASA@work, which was supported by the InnoCentive@work software platform. The objective of the NASA@work pilot was to connect the collective knowledge of individuals from all areas within the NASA organization via a private web based environment. The platform provided a venue for NASA Challenge Owners, those looking for solutions or new ideas, to pose challenges to internal solvers, those within NASA with the skill and desire to create solutions. The pilot was launched in 57 days, a record for InnoCentive and NASA, and ran for three months with a total of 20 challenges posted Agency wide. The NASA@work pilot attracted over 6000 participants throughout NASA with a total of 183 contributing solvers for the 20 challenges posted. At the time of the pilot?s closure, solvers provided viable solutions and ideas for 17 of the 20 posted challenges. The solver community provided feedback on the pilot describing it as a barrier breaking activity, conveying that there was a satisfaction associated with helping co-workers, that it was "fun" to think about problems outside normal work boundaries, and it was nice to learn what challenges others were facing across the agency. The results and the feedback from the solver community have demonstrated the power and utility of an internal collaboration tool, such as NASA@work.

Open Collaboration: A Problem Solving Strategy That is Redefining NASA's Innovative Spirit

NASA Technical Reports Server (NTRS)

Rando, Cynthia M.; Fogarty, Jennifer A.; Richard, E. E.; Davis, Jeffrey R.

2011-01-01

In 2010, NASA's Space Life Sciences Directorate announced the successful results from pilot experiments with open innovation methodologies. Specifically, utilization of internet based external crowdsourcing platforms to solve challenging problems in human health and performance related to the future of spaceflight. The follow-up to this success was an internal crowdsourcing pilot program entitled NASA@work, which was supported by the InnoCentive@work software platform. The objective of the NASA@work pilot was to connect the collective knowledge of individuals from all areas within the NASA organization via a private web based environment. The platform provided a venue for NASA Challenge Owners, those looking for solutions or new ideas, to pose challenges to internal solvers, those within NASA with the skill and desire to create solutions. The pilot was launched in 57 days, a record for InnoCentive and NASA, and ran for three months with a total of 20 challenges posted Agency wide. The NASA@work pilot attracted over 6,000 participants throughout NASA with a total of 183 contributing solvers for the 20 challenges posted. At the time of the pilot's closure, solvers provided viable solutions and ideas for 17 of the 20 posted challenges. The solver community provided feedback on the pilot describing it as a barrier breaking activity, conveying that there was a satisfaction associated with helping co-workers, that it was fun to think about problems outside normal work boundaries, and it was nice to learn what challenges others were facing across the agency. The results and the feedback from the solver community have demonstrated the power and utility of an internal collaboration tool, such as NASA@work.

Pre-service teachers’ challenges in presenting mathematical problems

NASA Astrophysics Data System (ADS)

Desfitri, R.

2018-01-01

The purpose of this study was to analyzed how pre-service teachers prepare and assigned tasks or assignments in teaching practice situations. This study was also intended to discuss about kind of tasks or assignments they gave to students. Participants of this study were 15 selected pre-service mathematics teachers from mathematics education department who took part on microteaching class as part of teaching preparation program. Based on data obtained, it was occasionally found that there were hidden errors on questions or tasks assigned by pre-service teachers which might lead their students not to be able to reach a logical or correct answer. Although some answers might seem to be true, they were illogical or unfavourable. It is strongly recommended that pre-service teachers be more careful when posing mathematical problems so that students do not misunderstand the problems or the concepts, since both teachers and students were sometimes unaware of errors in problems being worked on.

Sustainable Materials Management (SMM) Web Academy Webinar: An Introduction to Lithium Batteries and the Challenges that they Pose to the Waste and Recycling Industry

EPA Pesticide Factsheets

This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled, An Introduction to Lithium Batteries and the Challenges that they Pose to the Waste and Recycling Industry.

Career Counseling and the Information Highway: Heeding the Road Signs.

ERIC Educational Resources Information Center

O'Halloran, Theresa M.; Fahr, Alicia V.; Keller, Jenny R.

2002-01-01

Traveling the "information highway" in the process of career counseling or providing career counseling services via the Internet pose additional challenges for counselors. The authors use current ethical guidelines to guide discussion of, and possible resolutions to, challenges posed by incorporating the Internet into career counseling. (Contains…

Examining the Preparatory Effects of Problem Generation and Solution Generation on Learning from Instruction

ERIC Educational Resources Information Center

Kapur, Manu

2018-01-01

The goal of this paper is to isolate the preparatory effects of problem-generation from solution generation in problem-posing contexts, and their underlying mechanisms on learning from instruction. Using a randomized-controlled design, students were assigned to one of two conditions: (a) problem-posing with solution generation, where they…

Examining Interactions between Problem Posing and Problem Solving with Prospective Primary Teachers: A Case of Using Fractions

ERIC Educational Resources Information Center

Xie, Jinxia; Masingila, Joanna O.

2017-01-01

Existing studies have quantitatively evidenced the relatedness between problem posing and problem solving, as well as the magnitude of this relationship. However, the nature and features of this relationship need further qualitative exploration. This paper focuses on exploring the interactions, i.e., mutual effects and supports, between problem…

Improving attitudes toward mathematics learning with problem posing in class VIII

NASA Astrophysics Data System (ADS)

Vionita, Alfha; Purboningsih, Dyah

2017-08-01

This research is classroom action research which is collaborated to improve student's behavior toward math and mathematics learning at class VIII by using problem posing approach. The subject of research is all of students grade VIIIA which consist of 32 students. This research has been held on two period, first period is about 3 times meeting, and second period is about 4 times meeting. The instrument of this research is implementation of learning observation's guidance by using problem posing approach. Cycle test has been used to measure cognitive competence, and questionnaire to measure the students' behavior in mathematics learning process. The result of research shows the students' behavior has been improving after using problem posing approach. It is showed by the behavior's criteria of students that has increasing result from the average in first period to high in second period. Furthermore, the percentage of test result is also improve from 68,75% in first period to 78,13% in second period. On the other hand, the implementation of learning observation by using problem posing approach has also improving and it is showed by the average percentage of teacher's achievement in first period is 89,2% and student's achievement 85,8%. These results get increase in second period for both teacher and students' achievement which are 94,4% and 91,11%. As a result, students' behavior toward math learning process in class VIII has been improving by using problem posing approach.

A well-posed optimal spectral element approximation for the Stokes problem

NASA Technical Reports Server (NTRS)

Maday, Y.; Patera, A. T.; Ronquist, E. M.

1987-01-01

A method is proposed for the spectral element simulation of incompressible flow. This method constitutes in a well-posed optimal approximation of the steady Stokes problem with no spurious modes in the pressure. The resulting method is analyzed, and numerical results are presented for a model problem.

Pose and Solve Varignon Converse Problems

ERIC Educational Resources Information Center

Contreras, José N.

2014-01-01

The activity of posing and solving problems can enrich learners' mathematical experiences because it fosters a spirit of inquisitiveness, cultivates their mathematical curiosity, and deepens their views of what it means to do mathematics. To achieve these goals, a mathematical problem needs to be at the appropriate level of difficulty,…

Applications: Students, the Mathematics Curriculum and Mathematics Textbooks

ERIC Educational Resources Information Center

Kilic, Cigdem

2013-01-01

Problem posing is one of the most important topics in a mathematics education. Through problem posing, students gain mathematical abilities and concepts and teachers can evaluate their students and arrange adequate learning environments. The aim of the present study is to investigate Turkish primary school teachers' opinions about problem posing…

Investigating the Impact of Field Trips on Teachers' Mathematical Problem Posing

ERIC Educational Resources Information Center

Courtney, Scott A.; Caniglia, Joanne; Singh, Rashmi

2014-01-01

This study examines the impact of field trip experiences on teachers' mathematical problem posing. Teachers from a large urban public school system in the Midwest participated in a professional development program that incorporated experiential learning with mathematical problem formulation experiences. During 2 weeks of summer 2011, 68 teachers…

Social Entrepreneurship for Obesity Prevention: What Are the Opportunities?

PubMed

Smith, Tosha Woods; Calancie, Larissa; Ammerman, Alice

2015-09-01

In recent years, social entrepreneurship has emerged as a new field to address social and public health challenges. Social entrepreneurship, which harnesses traditional business practices and market forces to address social challenges, may produce solutions that are more cost-effective and sustainable than those produced by governmental and nonprofit sectors. In this paper, we discuss whether and how social entrepreneurship can be harnessed for obesity prevention by defining and briefly reviewing the rise of social entrepreneurship in the USA, outlining the threat that obesity poses to US society and offering some examples of how social ventures are addressing the problem of obesity. Additional untapped opportunities are also discussed and recommendations given for how social entrepreneurship might impact obesity prevention in the future.

Human genetic basis of interindividual variability in the course of infection

PubMed Central

Casanova, Jean-Laurent

2015-01-01

The key problem in human infectious diseases was posed at the turn of the 20th century: their pathogenesis. For almost any given virus, bacterium, fungus, or parasite, life-threatening clinical disease develops in only a small minority of infected individuals. Solving this infection enigma is important clinically, for diagnosis, prognosis, prevention, and treatment. Some microbes will inevitably remain refractory to, or escape vaccination, or chemotherapy, or both. The solution also is important biologically, because the emergence and evolution of eukaryotes alongside more rapidly evolving prokaryotes, archaea, and viruses posed immunological challenges of an ecological and evolutionary nature. We need to study these challenges in natural, as opposed to experimental, conditions, and also at the molecular and cellular levels. According to the human genetic theory of infectious diseases, inborn variants underlie life-threatening infectious diseases. Here I review the history of the field of human genetics of infectious diseases from the turn of the 19th century to the second half of the 20th century. This paper thus sets the scene, providing the background information required to understand and appreciate the more recently described monogenic forms of resistance or predisposition to specific infections discussed in a second paper in this issue. PMID:26621739

Cultural and Political Vignettes in the English Classroom: Problem-Posing, Problem-Solving, and the Imagination

ERIC Educational Resources Information Center

Darvin, Jacqueline

2009-01-01

One way to merge imagination with problem-posing and problem-solving in the English classroom is by asking students to respond to "cultural and political vignettes" (CPVs). CPVs are cultural and political situations that are presented to students so that they can practice the creative and essential decision-making skills that they will need to use…

High-School Students' Approaches to Solving Algebra Problems that Are Posed Symbolically: Results from an Interview Study

ERIC Educational Resources Information Center

Huntley, Mary Ann; Davis, Jon D.

2008-01-01

A cross-curricular structured-probe task-based clinical interview study with 44 pairs of third year high-school mathematics students, most of whom were high achieving, was conducted to investigate their approaches to a variety of algebra problems. This paper presents results from three problems that were posed in symbolic form. Two problems are…

Large strain dynamic compression for soft materials using a direct impact experiment

NASA Astrophysics Data System (ADS)

Meenken, T.; Hiermaier, S.

2006-08-01

Measurement of strain rate dependent material data of low density low strength materials like polymeric foams and rubbers still poses challenges of a different kind to the experimental set up. For instance, in conventional Split Hopkinson Pressure Bar tests the impedance mismatch between the bars and the specimen makes strain measurement almost impossible. Application of viscoelastic bars poses new problems with wave dispersion. Also, maximum achievable strains and strain rates depend directly on the bar lengths, resulting in large experimental set ups in order to measure relevant data for automobile crash applications. In this paper a modified SHPB will be presented for testing low impedance materials. High strains can be achieved with nearly constant strain rate. A thin film stress measurement has been applied to the specimen/bar interfaces to investigate the initial sample ring up process. The process of stress homogeneity within the sample was investigated on EPDM and PU rubber.

Human body segmentation via data-driven graph cut.

PubMed

Li, Shifeng; Lu, Huchuan; Shao, Xingqing

2014-11-01

Human body segmentation is a challenging and important problem in computer vision. Existing methods usually entail a time-consuming training phase for prior knowledge learning with complex shape matching for body segmentation. In this paper, we propose a data-driven method that integrates top-down body pose information and bottom-up low-level visual cues for segmenting humans in static images within the graph cut framework. The key idea of our approach is first to exploit human kinematics to search for body part candidates via dynamic programming for high-level evidence. Then, by using the body parts classifiers, obtaining bottom-up cues of human body distribution for low-level evidence. All the evidence collected from top-down and bottom-up procedures are integrated in a graph cut framework for human body segmentation. Qualitative and quantitative experiment results demonstrate the merits of the proposed method in segmenting human bodies with arbitrary poses from cluttered backgrounds.

Is pretenure interdisciplinary research a career risk?

NASA Astrophysics Data System (ADS)

Fischer, E. V.; Mackey, K. R. M.; Cusack, D. F.; DeSantis, L. R. G.; Hartzell-Nichols, L.; Lutz, J. A.; Melbourne-Thomas, J.; Meyer, R.; Riveros-Iregui, D. A.; Sorte, C. J. B.; Taylor, J. R.; White, S. A.

2012-08-01

Despite initiatives to promote interdisciplinary research, early-career academics continue to perceive professional risks to working at the interface between traditional disciplines. Unexpectedly, the inherent practical challenges of interdisciplinary scholarship, such as new methodologies and lexicons, are not the chief source of the perceived risk. The perception of risk is pervasive across disciplines, and it persists despite efforts to support career development for individuals with common interests [Mitchell and Weiler, 2011]. Suggestions that interdisciplinary work can go unrewarded in academia [Clark et al., 2011] foster a concern that targeting interdisciplinary questions, such as those presented by climate change, will pose problems for acquiring and succeeding in a tenure-track position. If self-preservation limits the questions posed by early-career academics, a perceived career risk is as damaging as a real one to new transdisciplinary initiatives. Thus, institutions should address the source of this perception whether real or specious.

Mining the Quantified Self: Personal Knowledge Discovery as a Challenge for Data Science.

PubMed

Fawcett, Tom

2015-12-01

The last several years have seen an explosion of interest in wearable computing, personal tracking devices, and the so-called quantified self (QS) movement. Quantified self involves ordinary people recording and analyzing numerous aspects of their lives to understand and improve themselves. This is now a mainstream phenomenon, attracting a great deal of attention, participation, and funding. As more people are attracted to the movement, companies are offering various new platforms (hardware and software) that allow ever more aspects of daily life to be tracked. Nearly every aspect of the QS ecosystem is advancing rapidly, except for analytic capabilities, which remain surprisingly primitive. With increasing numbers of qualified self participants collecting ever greater amounts and types of data, many people literally have more data than they know what to do with. This article reviews the opportunities and challenges posed by the QS movement. Data science provides well-tested techniques for knowledge discovery. But making these useful for the QS domain poses unique challenges that derive from the characteristics of the data collected as well as the specific types of actionable insights that people want from the data. Using a small sample of QS time series data containing information about personal health we provide a formulation of the QS problem that connects data to the decisions of interest to the user.

Verification of Eulerian-Eulerian and Eulerian-Lagrangian simulations for fluid-particle flows

NASA Astrophysics Data System (ADS)

Kong, Bo; Patel, Ravi G.; Capecelatro, Jesse; Desjardins, Olivier; Fox, Rodney O.

2017-11-01

In this work, we study the performance of three simulation techniques for fluid-particle flows: (1) a volume-filtered Euler-Lagrange approach (EL), (2) a quadrature-based moment method using the anisotropic Gaussian closure (AG), and (3) a traditional two-fluid model. By simulating two problems: particles in frozen homogeneous isotropic turbulence (HIT), and cluster-induced turbulence (CIT), the convergence of the methods under grid refinement is found to depend on the simulation method and the specific problem, with CIT simulations facing fewer difficulties than HIT. Although EL converges under refinement for both HIT and CIT, its statistical results exhibit dependence on the techniques used to extract statistics for the particle phase. For HIT, converging both EE methods (TFM and AG) poses challenges, while for CIT, AG and EL produce similar results. Overall, all three methods face challenges when trying to extract converged, parameter-independent statistics due to the presence of shocks in the particle phase. National Science Foundation and National Energy Technology Laboratory.

Rigged or rigorous? Partnerships for research and evaluation of complex social problems: Lessons from the field of violence against women and girls.

PubMed

Zimmerman, Cathy; Michau, Lori; Hossain, Mazeda; Kiss, Ligia; Borland, Rosilyne; Watts, Charlotte

2016-09-01

There is growing demand for robust evidence to address complex social phenomena such as violence against women and girls (VAWG). Research partnerships between scientists and non-governmental or international organizations (NGO/IO) are increasingly popular, but can pose challenges, including concerns about potential conflicts of interest. Drawing on our experience collaborating on VAWG research, we describe challenges and contributions that NGO/IO and academic partners can make at different stages of the research process and the effects that collaborations can have on scientific inquiry. Partners may struggle with differing priorities and misunderstandings about roles, limitations, and intentions. Benefits of partnerships include a shared vision of study goals, differing and complementary expertise, mutual respect, and a history of constructive collaboration. Our experience suggests that when investigating multi-faceted social problems, instead of 'rigging' study results, research collaborations can strengthen scientific rigor and offer the greatest potential for impact in the communities we seek to serve.

Verification of Eulerian-Eulerian and Eulerian-Lagrangian simulations for turbulent fluid-particle flows

DOE PAGES

Patel, Ravi G.; Desjardins, Olivier; Kong, Bo; ...

2017-09-01

Here, we present a verification study of three simulation techniques for fluid–particle flows, including an Euler–Lagrange approach (EL) inspired by Jackson's seminal work on fluidized particles, a quadrature–based moment method based on the anisotropic Gaussian closure (AG), and the traditional two-fluid model. We perform simulations of two problems: particles in frozen homogeneous isotropic turbulence (HIT) and cluster-induced turbulence (CIT). For verification, we evaluate various techniques for extracting statistics from EL and study the convergence properties of the three methods under grid refinement. The convergence is found to depend on the simulation method and on the problem, with CIT simulations posingmore » fewer difficulties than HIT. Specifically, EL converges under refinement for both HIT and CIT, but statistics exhibit dependence on the postprocessing parameters. For CIT, AG produces similar results to EL. For HIT, converging both TFM and AG poses challenges. Overall, extracting converged, parameter-independent Eulerian statistics remains a challenge for all methods.« less

Transparent data service with multiple wireless access

NASA Technical Reports Server (NTRS)

Dean, Richard A.; Levesque, Allen H.

1993-01-01

The rapid introduction of digital wireless networks is an important part of the emerging digital communications scene. The introduction of Digital Cellular, LEO and GEO Satellites, and Personal Communications Services poses both a challenge and an opportunity for the data user. On the one hand wireless access will introduce significant new portable data services such as personal notebooks, paging, E-mail, and fax that will put the information age in the user's pocket. On the other hand the challenge of creating a seamless and transparent environment for the user in multiple access environments and across multiple network connections is formidable. A summary of the issues associated with developing techniques and standards that can support transparent and seamless data services is presented. The introduction of data services into the radio world represents a unique mix of RF channel problems, data protocol issues, and network issues. These problems require that experts from each of these disciplines fuse the individual technologies to support these services.

Verification of Eulerian-Eulerian and Eulerian-Lagrangian simulations for turbulent fluid-particle flows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patel, Ravi G.; Desjardins, Olivier; Kong, Bo

Here, we present a verification study of three simulation techniques for fluid–particle flows, including an Euler–Lagrange approach (EL) inspired by Jackson's seminal work on fluidized particles, a quadrature–based moment method based on the anisotropic Gaussian closure (AG), and the traditional two-fluid model. We perform simulations of two problems: particles in frozen homogeneous isotropic turbulence (HIT) and cluster-induced turbulence (CIT). For verification, we evaluate various techniques for extracting statistics from EL and study the convergence properties of the three methods under grid refinement. The convergence is found to depend on the simulation method and on the problem, with CIT simulations posingmore » fewer difficulties than HIT. Specifically, EL converges under refinement for both HIT and CIT, but statistics exhibit dependence on the postprocessing parameters. For CIT, AG produces similar results to EL. For HIT, converging both TFM and AG poses challenges. Overall, extracting converged, parameter-independent Eulerian statistics remains a challenge for all methods.« less

Translational Biomedical Informatics in the Cloud: Present and Future

PubMed Central

Chen, Jiajia; Qian, Fuliang; Yan, Wenying; Shen, Bairong

2013-01-01

Next generation sequencing and other high-throughput experimental techniques of recent decades have driven the exponential growth in publicly available molecular and clinical data. This information explosion has prepared the ground for the development of translational bioinformatics. The scale and dimensionality of data, however, pose obvious challenges in data mining, storage, and integration. In this paper we demonstrated the utility and promise of cloud computing for tackling the big data problems. We also outline our vision that cloud computing could be an enabling tool to facilitate translational bioinformatics research. PMID:23586054

Ergonomics, education and children: a personal view.

PubMed

Woodcock, A

2007-10-01

Educational ergonomics - the teaching of ergonomics and the design of environments where ergonomics teaching and learning might occur - has received little attention from ergonomists. This paper first describes the roots of the author's interest and research in educational ergonomics; second it provides a personal view of the opportunities and challenges posed by the two streams of educational ergonomics; and lastly it considers the implications of teaching ergonomics to children in terms of their personal development, the design of schools and the impact such initiatives might have on wider societal problems.

Virtualization in education: Information Security lab in your hands

NASA Astrophysics Data System (ADS)

Karlov, A. A.

2016-09-01

The growing demand for qualified specialists in advanced information technologies poses serious challenges to the education and training of young personnel for science, industry and social problems. Virtualization as a way to isolate the user from the physical characteristics of computing resources (processors, servers, operating systems, networks, applications, etc.), has, in particular, an enormous influence in the field of education, increasing its efficiency, reducing the cost, making it more widely and readily available. The study of Information Security of computer systems is considered as an example of use of virtualization in education.

The Galileo Attitude and Articulation Control System - A radiation-hard, high precision, state-of-the-art control system

NASA Technical Reports Server (NTRS)

Rhoads Stephenson, R.

1986-01-01

The Galileo Mission and Spacecraft design impose tight requirements on the Attitude and Articulation Control System (AACS). These requirements, coupled with the flexible spacecraft, the need for autonomy, and a severe radiation environment, pose a great challenge for the AACS designer. The resulting design and implementation are described, along with the discovery and solution of the Single-Event Upset problem. The status of the testing of the AACS in the Integration and Test Laboratory as well as at the spacecraft level is summarized.

A truncated generalized singular value decomposition algorithm for moving force identification with ill-posed problems

NASA Astrophysics Data System (ADS)

Chen, Zhen; Chan, Tommy H. T.

2017-08-01

This paper proposes a new methodology for moving force identification (MFI) from the responses of bridge deck. Based on the existing time domain method (TDM), the MFI problem eventually becomes solving the linear algebraic equation in the form Ax = b . The vector b is usually contaminated by an unknown error e generating from measurement error, which often called the vector e as ''noise''. With the ill-posed problems that exist in the inverse problem, the identification force would be sensitive to the noise e . The proposed truncated generalized singular value decomposition method (TGSVD) aims at obtaining an acceptable solution and making the noise to be less sensitive to perturbations with the ill-posed problems. The illustrated results show that the TGSVD has many advantages such as higher precision, better adaptability and noise immunity compared with TDM. In addition, choosing a proper regularization matrix L and a truncation parameter k are very useful to improve the identification accuracy and to solve ill-posed problems when it is used to identify the moving force on bridge.

A non-conventional discontinuous Lagrangian for viscous flow

PubMed Central

Marner, F.

2017-01-01

Drawing an analogy with quantum mechanics, a new Lagrangian is proposed for a variational formulation of the Navier–Stokes equations which to-date has remained elusive. A key feature is that the resulting Lagrangian is discontinuous in nature, posing additional challenges apropos the mathematical treatment of the related variational problem, all of which are resolvable. In addition to extending Lagrange's formalism to problems involving discontinuous behaviour, it is demonstrated that the associated equations of motion can self-consistently be interpreted within the framework of thermodynamics beyond local equilibrium, with the limiting case recovering the classical Navier–Stokes equations. Perspectives for applying the new formalism to discontinuous physical phenomena such as phase and grain boundaries, shock waves and flame fronts are provided. PMID:28386415

Explicit solution techniques for impact with contact constraints

NASA Technical Reports Server (NTRS)

Mccarty, Robert E.

1993-01-01

Modern military aircraft transparency systems, windshields and canopies, are complex systems which must meet a large and rapidly growing number of requirements. Many of these transparency system requirements are conflicting, presenting difficult balances which must be achieved. One example of a challenging requirements balance or trade is shaping for stealth versus aircrew vision. The large number of requirements involved may be grouped in a variety of areas including man-machine interface; structural integration with the airframe; combat hazards; environmental exposures; and supportability. Some individual requirements by themselves pose very difficult, severely nonlinear analysis problems. One such complex problem is that associated with the dynamic structural response resulting from high energy bird impact. An improved analytical capability for soft-body impact simulation was developed.

Explicit solution techniques for impact with contact constraints

NASA Astrophysics Data System (ADS)

McCarty, Robert E.

1993-08-01

Modern military aircraft transparency systems, windshields and canopies, are complex systems which must meet a large and rapidly growing number of requirements. Many of these transparency system requirements are conflicting, presenting difficult balances which must be achieved. One example of a challenging requirements balance or trade is shaping for stealth versus aircrew vision. The large number of requirements involved may be grouped in a variety of areas including man-machine interface; structural integration with the airframe; combat hazards; environmental exposures; and supportability. Some individual requirements by themselves pose very difficult, severely nonlinear analysis problems. One such complex problem is that associated with the dynamic structural response resulting from high energy bird impact. An improved analytical capability for soft-body impact simulation was developed.

Solving the quantum many-body problem with artificial neural networks

NASA Astrophysics Data System (ADS)

Carleo, Giuseppe; Troyer, Matthias

2017-02-01

The challenge posed by the many-body problem in quantum physics originates from the difficulty of describing the nontrivial correlations encoded in the exponential complexity of the many-body wave function. Here we demonstrate that systematic machine learning of the wave function can reduce this complexity to a tractable computational form for some notable cases of physical interest. We introduce a variational representation of quantum states based on artificial neural networks with a variable number of hidden neurons. A reinforcement-learning scheme we demonstrate is capable of both finding the ground state and describing the unitary time evolution of complex interacting quantum systems. Our approach achieves high accuracy in describing prototypical interacting spins models in one and two dimensions.

A non-conventional discontinuous Lagrangian for viscous flow.

PubMed

Scholle, M; Marner, F

2017-02-01

Drawing an analogy with quantum mechanics, a new Lagrangian is proposed for a variational formulation of the Navier-Stokes equations which to-date has remained elusive. A key feature is that the resulting Lagrangian is discontinuous in nature, posing additional challenges apropos the mathematical treatment of the related variational problem, all of which are resolvable. In addition to extending Lagrange's formalism to problems involving discontinuous behaviour, it is demonstrated that the associated equations of motion can self-consistently be interpreted within the framework of thermodynamics beyond local equilibrium, with the limiting case recovering the classical Navier-Stokes equations. Perspectives for applying the new formalism to discontinuous physical phenomena such as phase and grain boundaries, shock waves and flame fronts are provided.

Distributed computation: the new wave of synthetic biology devices.

PubMed

Macía, Javier; Posas, Francesc; Solé, Ricard V

2012-06-01

Synthetic biology (SB) offers a unique opportunity for designing complex molecular circuits able to perform predefined functions. But the goal of achieving a flexible toolbox of reusable molecular components has been shown to be limited due to circuit unpredictability, incompatible parts or random fluctuations. Many of these problems arise from the challenges posed by engineering the molecular circuitry: multiple wires are usually difficult to implement reliably within one cell and the resulting systems cannot be reused in other modules. These problems are solved by means of a nonstandard approach to single cell devices, using cell consortia and allowing the output signal to be distributed among different cell types, which can be combined in multiple, reusable and scalable ways. Copyright © 2012 Elsevier Ltd. All rights reserved.

Tecnología Digital y Formulación de Problemas durante el Proceso de Resolución de Problemas = Digital Technology and Formulation of Problems during the Process of Solving Problems

ERIC Educational Resources Information Center

Aguilar-Magallón, Daniel Aurelio; Reyes-Martìnez, Isaid

2016-01-01

We analyze and discuss ways in which prospective high school teachers pose and pursue questions or problems during the process of reconstructing dynamic configurations of figures given in problem statements. To what extent does the systematic use of a Dynamic Geometry System (DGS) help the participants engage in problem posing activities…

A Violent Birth: Reframing Coerced Procedures During Childbirth as Obstetric Violence.

PubMed

Borges, Maria TR

2018-01-01

In the United States, women are routinely forced to undergo cesarean sections, episiotomies, and the use of forceps, despite their desire to attempt natural vaginal delivery. Yet, the current American legal system does little to provide redress for women coerced to undergo certain medical procedures during childbirth. Courts and physicians alike are prepared to override a woman's choice of childbirth procedure if they believe this choice poses risks to the fetus, and both give little value to the woman's right to bodily autonomy. This Note proposes a solution for addressing the problem of coerced medical procedures during childbirth by importing a framework created in Venezuela and Argentina that characterizes this issue as "obstetric violence." First, this Note contains an overview of the shortcomings of the existing American legal framework to address the problem. Second, it explains the advantages of the obstetric violence framework and argues that its adoption in the United States would address many of the failures of the existing system. And third, this Note introduces a few legislative and litigation strategies that can be used to implement this framework in the United States and briefly addresses some of the challenges these strategies may pose.

Validation of a computerized technique for automatically tracking and measuring the inferior vena cava in ultrasound imagery.

PubMed

Bellows, Spencer; Smith, Jordan; Mcguire, Peter; Smith, Andrew

2014-01-01

Accurate resuscitation of the critically-ill patient using intravenous fluids and blood products is a challenging, time sensitive task. Ultrasound of the inferior vena cava (IVC) is a non-invasive technique currently used to guide fluid administration, though multiple factors such as variable image quality, time, and operator skill challenge mainstream acceptance. This study represents a first attempt to develop and validate an algorithm capable of automatically tracking and measuring the IVC compared to human operators across a diverse range of image quality. Minimal tracking failures and high levels of agreement between manual and algorithm measurements were demonstrated on good quality videos. Addressing problems such as gaps in the vessel wall and intra-lumen speckle should result in improved performance in average and poor quality videos. Semi-automated measurement of the IVC for the purposes of non-invasive estimation of circulating blood volume poses challenges however is feasible.

Biomimetics and the Development of Humanlike Robots as the Ultimate Challenge

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph

2011-01-01

Evolution led to effective solutions to nature's challenges and they were improved over millions of years. Humans have always made efforts to use nature as a model for innovation and problems solving. These efforts became more intensive in recent years where systematic studies of nature are being made towards better understanding and applying more sophisticated capabilities. Making humanlike robots, including the appearance, functions and intelligence, poses the ultimate challenges to biomimetics. For many years, making such robots was considered science fiction, but as a result of significant advances in biologically inspired technologies, such robots are increasingly becoming an engineering reality. There are already humanlike robots that walk, talk, interpret speech, make eye-contact and facial expressions, as well as perform many other humanlike functions. In this paper, the state-of-the-art of humanlike robots, potential applications and issues of concern will be reviewed.

Knowledge networks for global public health.

PubMed

Natividad, Maria Dulce F; Fiereck, Kirk J; Parker, Richard

2012-01-01

The challenges posed by a globalised world have made it imperative for society to search for solutions to emerging issues and to develop new ways of looking at old problems. Current discussions about global public health demand a shift in paradigms and the strategic positioning of public health within broader policy discussions that will enable it to influence political and action agendas. Critical to responding to these challenges is the generation, transmission and dissemination of new knowledge to create value. Recognising the cutting-edge role of knowledge, as a new form of capital that drives innovation and transforms society, the formation of knowledge networks is viewed as a strategy for developing a shared intellectual, conceptual and ethical infrastructure for the field of global public health. These knowledge networks are envisioned as a vehicle for sharing diverse perspectives, encouraging debate and sustaining alternative ways of thinking about and responding to the challenges that confront global public health today and in the future.

Self-deconstructing algae biomass as feedstock for transportation fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, Ryan Wesley

The potential for producing biofuels from algae has generated much excitement based on projections of large oil yields with relatively little land use. However, numerous technical challenges remain for achieving market parity with conventional non-renewable liquid fuel sources. Among these challenges, the energy intensive requirements of traditional cell rupture, lipid extraction, and residuals fractioning of microalgae biomass have posed significant challenges to the nascent field of algal biotechnology. Our novel approach to address these problems was to employ low cost solution-state methods and biochemical engineering to eliminate the need for extensive hardware and energy intensive methods for cell rupture, carbohydratemore » and protein solubilization and hydrolysis, and fuel product recovery using consolidated bioprocessing strategies. The outcome of the biochemical deconstruction and conversion process consists of an emulsion of algal lipids and mixed alcohol products from carbohydrate and protein fermentation for co-extraction or in situ transesterification.« less

Digital Pharmacovigilance and Disease Surveillance: Combining Traditional and Big-Data Systems for Better Public Health

PubMed Central

Salathé, Marcel

2016-01-01

The digital revolution has contributed to very large data sets (ie, big data) relevant for public health. The two major data sources are electronic health records from traditional health systems and patient-generated data. As the two data sources have complementary strengths—high veracity in the data from traditional sources and high velocity and variety in patient-generated data—they can be combined to build more-robust public health systems. However, they also have unique challenges. Patient-generated data in particular are often completely unstructured and highly context dependent, posing essentially a machine-learning challenge. Some recent examples from infectious disease surveillance and adverse drug event monitoring demonstrate that the technical challenges can be solved. Despite these advances, the problem of verification remains, and unless traditional and digital epidemiologic approaches are combined, these data sources will be constrained by their intrinsic limits. PMID:28830106

An experimental comparison of online object-tracking algorithms

NASA Astrophysics Data System (ADS)

Wang, Qing; Chen, Feng; Xu, Wenli; Yang, Ming-Hsuan

2011-09-01

This paper reviews and evaluates several state-of-the-art online object tracking algorithms. Notwithstanding decades of efforts, object tracking remains a challenging problem due to factors such as illumination, pose, scale, deformation, motion blur, noise, and occlusion. To account for appearance change, most recent tracking algorithms focus on robust object representations and effective state prediction. In this paper, we analyze the components of each tracking method and identify their key roles in dealing with specific challenges, thereby shedding light on how to choose and design algorithms for different situations. We compare state-of-the-art online tracking methods including the IVT,1 VRT,2 FragT,3 BoostT,4 SemiT,5 BeSemiT,6 L1T,7 MILT,8 VTD9 and TLD10 algorithms on numerous challenging sequences, and evaluate them with different performance metrics. The qualitative and quantitative comparative results demonstrate the strength and weakness of these algorithms.

Lessons about Climate Change Pose Many Challenges for Science Teachers

ERIC Educational Resources Information Center

Cavanagh, Sean

2007-01-01

This article reports on lessons about climate change which pose many challenges for science teachers. The natural world today offers a broad--and dire--catalog of scientific phenomena for teachers wanting to craft classroom lessons on the topic of climate change. As public concern about global warming increases, teachers are carving out a larger…

Solving ill-posed control problems by stabilized finite element methods: an alternative to Tikhonov regularization

NASA Astrophysics Data System (ADS)

Burman, Erik; Hansbo, Peter; Larson, Mats G.

2018-03-01

Tikhonov regularization is one of the most commonly used methods for the regularization of ill-posed problems. In the setting of finite element solutions of elliptic partial differential control problems, Tikhonov regularization amounts to adding suitably weighted least squares terms of the control variable, or derivatives thereof, to the Lagrangian determining the optimality system. In this note we show that the stabilization methods for discretely ill-posed problems developed in the setting of convection-dominated convection-diffusion problems, can be highly suitable for stabilizing optimal control problems, and that Tikhonov regularization will lead to less accurate discrete solutions. We consider some inverse problems for Poisson’s equation as an illustration and derive new error estimates both for the reconstruction of the solution from the measured data and reconstruction of the source term from the measured data. These estimates include both the effect of the discretization error and error in the measurements.

The opportunities and challenges of multi-site evaluations: lessons from the jail diversion and trauma recovery national cross-site evaluation.

PubMed

Stainbrook, Kristin; Penney, Darby; Elwyn, Laura

2015-06-01

Multi-site evaluations, particularly of federally funded service programs, pose a special set of challenges for program evaluation. Not only are there contextual differences related to project location, there are often relatively few programmatic requirements, which results in variations in program models, target populations and services. The Jail Diversion and Trauma Recovery-Priority to Veterans (JDTR) National Cross-Site Evaluation was tasked with conducting a multi-site evaluation of thirteen grantee programs that varied along multiple domains. This article describes the use of a mixed methods evaluation design to understand the jail diversion programs and client outcomes for veterans with trauma, mental health and/or substance use problems. We discuss the challenges encountered in evaluating diverse programs, the benefits of the evaluation in the face of these challenges, and offer lessons learned for other evaluators undertaking this type of evaluation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Military children and families: strengths and challenges during peace and war.

PubMed

Park, Nansook

2011-01-01

Throughout history, military children and families have shown great capacity for adaptation and resilience. However, in recent years, unprecedented lengthy and multiple combat deployments of service members have posed multiple challenges for U.S. military children and families. Despite needs to better understand the impact of deployment on military children and families and to provide proper support for them, rigorous research is lacking. Programs exist that are intended to help, but their effectiveness is largely unknown. They need to be better coordinated and delivered at the level of individuals, families, and communities. Research and programs need to take a comprehensive approach that is strengths based and problem focused. Programs for military children and families often focus on the prevention or reduction of problems. It is just as important to recognize their assets and to promote them. This article reviews existing research on military children and families, with attention to their strengths as well as their challenges. Issues in need of further research are identified, especially research into programs that assist military children and families. Military children and families deserve greater attention from psychology. (c) 2010 APA, all rights reserved.

Human Pose Estimation from Monocular Images: A Comprehensive Survey

PubMed Central

Gong, Wenjuan; Zhang, Xuena; Gonzàlez, Jordi; Sobral, Andrews; Bouwmans, Thierry; Tu, Changhe; Zahzah, El-hadi

2016-01-01

Human pose estimation refers to the estimation of the location of body parts and how they are connected in an image. Human pose estimation from monocular images has wide applications (e.g., image indexing). Several surveys on human pose estimation can be found in the literature, but they focus on a certain category; for example, model-based approaches or human motion analysis, etc. As far as we know, an overall review of this problem domain has yet to be provided. Furthermore, recent advancements based on deep learning have brought novel algorithms for this problem. In this paper, a comprehensive survey of human pose estimation from monocular images is carried out including milestone works and recent advancements. Based on one standard pipeline for the solution of computer vision problems, this survey splits the problem into several modules: feature extraction and description, human body models, and modeling methods. Problem modeling methods are approached based on two means of categorization in this survey. One way to categorize includes top-down and bottom-up methods, and another way includes generative and discriminative methods. Considering the fact that one direct application of human pose estimation is to provide initialization for automatic video surveillance, there are additional sections for motion-related methods in all modules: motion features, motion models, and motion-based methods. Finally, the paper also collects 26 publicly available data sets for validation and provides error measurement methods that are frequently used. PMID:27898003

Investigation of finite element: ABC methods for electromagnetic field simulation. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Chatterjee, A.; Volakis, John L.; Nguyen, J.

1994-01-01

The mechanics of wave propagation in the presence of obstacles is of great interest in many branches of engineering and applied mathematics like electromagnetics, fluid dynamics, geophysics, seismology, etc. Such problems can be broadly classified into two categories: the bounded domain or the closed problem and the unbounded domain or the open problem. Analytical techniques have been derived for the simpler problems; however, the need to model complicated geometrical features, complex material coatings and fillings, and to adapt the model to changing design parameters have inevitably tilted the balance in favor of numerical techniques. The modeling of closed problems presents difficulties primarily in proper meshing of the interior region. However, problems in unbounded domains pose a unique challenge to computation, since the exterior region is inappropriate for direct implementation of numerical techniques. A large number of solutions have been proposed but only a few have stood the test of time and experiment. The goal of this thesis is to develop an efficient and reliable partial differential equation technique to model large three dimensional scattering problems in electromagnetics.

Ranking docking poses by graph matching of protein-ligand interactions: lessons learned from the D3R Grand Challenge 2

NASA Astrophysics Data System (ADS)

da Silva Figueiredo Celestino Gomes, Priscila; Da Silva, Franck; Bret, Guillaume; Rognan, Didier

2018-01-01

A novel docking challenge has been set by the Drug Design Data Resource (D3R) in order to predict the pose and affinity ranking of a set of Farnesoid X receptor (FXR) agonists, prior to the public release of their bound X-ray structures and potencies. In a first phase, 36 agonists were docked to 26 Protein Data Bank (PDB) structures of the FXR receptor, and next rescored using the in-house developed GRIM method. GRIM aligns protein-ligand interaction patterns of docked poses to those of available PDB templates for the target protein, and rescore poses by a graph matching method. In agreement with results obtained during the previous 2015 docking challenge, we clearly show that GRIM rescoring improves the overall quality of top-ranked poses by prioritizing interaction patterns already visited in the PDB. Importantly, this challenge enables us to refine the applicability domain of the method by better defining the conditions of its success. We notably show that rescoring apolar ligands in hydrophobic pockets leads to frequent GRIM failures. In the second phase, 102 FXR agonists were ranked by decreasing affinity according to the Gibbs free energy of the corresponding GRIM-selected poses, computed by the HYDE scoring function. Interestingly, this fast and simple rescoring scheme provided the third most accurate ranking method among 57 contributions. Although the obtained ranking is still unsuitable for hit to lead optimization, the GRIM-HYDE scoring scheme is accurate and fast enough to post-process virtual screening data.

A Nonrigid Kernel-Based Framework for 2D-3D Pose Estimation and 2D Image Segmentation

PubMed Central

Sandhu, Romeil; Dambreville, Samuel; Yezzi, Anthony; Tannenbaum, Allen

2013-01-01

In this work, we present a nonrigid approach to jointly solving the tasks of 2D-3D pose estimation and 2D image segmentation. In general, most frameworks that couple both pose estimation and segmentation assume that one has exact knowledge of the 3D object. However, under nonideal conditions, this assumption may be violated if only a general class to which a given shape belongs is given (e.g., cars, boats, or planes). Thus, we propose to solve the 2D-3D pose estimation and 2D image segmentation via nonlinear manifold learning of 3D embedded shapes for a general class of objects or deformations for which one may not be able to associate a skeleton model. Thus, the novelty of our method is threefold: First, we present and derive a gradient flow for the task of nonrigid pose estimation and segmentation. Second, due to the possible nonlinear structures of one’s training set, we evolve the preimage obtained through kernel PCA for the task of shape analysis. Third, we show that the derivation for shape weights is general. This allows us to use various kernels, as well as other statistical learning methodologies, with only minimal changes needing to be made to the overall shape evolution scheme. In contrast with other techniques, we approach the nonrigid problem, which is an infinite-dimensional task, with a finite-dimensional optimization scheme. More importantly, we do not explicitly need to know the interaction between various shapes such as that needed for skeleton models as this is done implicitly through shape learning. We provide experimental results on several challenging pose estimation and segmentation scenarios. PMID:20733218

Regularization techniques for backward--in--time evolutionary PDE problems

NASA Astrophysics Data System (ADS)

Gustafsson, Jonathan; Protas, Bartosz

2007-11-01

Backward--in--time evolutionary PDE problems have applications in the recently--proposed retrograde data assimilation. We consider the terminal value problem for the Kuramoto--Sivashinsky equation (KSE) in a 1D periodic domain as our model system. The KSE, proposed as a model for interfacial and combustion phenomena, is also often adopted as a toy model for hydrodynamic turbulence because of its multiscale and chaotic dynamics. Backward--in--time problems are typical examples of ill-posed problem, where disturbances are amplified exponentially during the backward march. Regularization is required to solve such problems efficiently and we consider approaches in which the original ill--posed problem is approximated with a less ill--posed problem obtained by adding a regularization term to the original equation. While such techniques are relatively well--understood for linear problems, they less understood in the present nonlinear setting. We consider regularization terms with fixed magnitudes and also explore a novel approach in which these magnitudes are adapted dynamically using simple concepts from the Control Theory.

Student-Posed Problems

NASA Astrophysics Data System (ADS)

Harper, Kathleen A.; Etkina, Eugenia

2002-10-01

As part of weekly reports,1 structured journals in which students answer three standard questions each week, they respond to the prompt, If I were the instructor, what questions would I ask or problems assign to determine if my students understood the material? An initial analysis of the results shows that some student-generated problems indicate fundamental misunderstandings of basic physical concepts. A further investigation explores the relevance of the problems to the week's material, whether the problems are solvable, and the type of problems (conceptual or calculation-based) written. Also, possible links between various characteristics of the problems and conceptual achievement are being explored. The results of this study spark many more questions for further work. A summary of current findings will be presented, along with its relationship to previous work concerning problem posing.2 1Etkina, E. Weekly Reports;A Two-Way Feedback Tool, Science Education, 84, 594-605 (2000). 2Mestre, J.P., Probing Adults Conceptual Understanding and Transfer of Learning Via Problem Posing, Journal of Applied Developmental Psychology, 23, 9-50 (2002).

Ill Posed Problems: Numerical and Statistical Methods for Mildly, Moderately and Severely Ill Posed Problems with Noisy Data.

DTIC Science & Technology

1980-02-01

to estimate f -..ell, -noderately ,-ell, or- poorly. 1 ’The sansitivity *of a rec-ilarized estimate of f to the noise is made explicit. After giving the...AD-A 7 .SA92 925 WISCONSIN UN! V-MADISON DEFT OF STATISTICS F /S 11,’ 1 ILL POSED PRORLEMS: NUMERICAL ANn STATISTICAL METHODS FOR MILOL-ETC(U FEB 80 a...estimate f given z. We first define the 1 intrinsic rank of the problem where jK(tit) f (t)dt is known exactly. This 0 definition is used to provide insight

Carbon Dioxide Impacts in the Deep-Sea: Is Maintaining a Metabolically Required CO2 Efflux Rate Challenging?

NASA Astrophysics Data System (ADS)

Peltzer, E. T.; Hofmann, A. F.; Brewer, P. G.

2011-12-01

Increasing ocean acidification from fossil fuel CO2 invasion, from temperature driven changes in respiration, and from possible leakage from sub-seabed geologic CO2 disposal has aroused concern over the impacts of elevated CO2 concentrations on marine life. Here we describe the rate problem for animals who must export CO2 at about the same rate at which O2 is consumed. We analyze the basic properties controlling CO2 export within the diffusive boundary of marine animals in a changing ocean in order to compare the challenges posed by O2 uptake under stress with the equivalent problem of CO2 expulsion. The problem is more complex than that for a non-reactive gas since, as with gas exchange of CO2 at the air-sea interface, the influence of the ensemble of reactions within the CO2 - HCO3- - CO3= acid-base system needs to be considered. These reactions appear as an enhancement factor which significantly facilitates CO2 efflux compared to O2 intake at equal temperature, pressure and flow rate under typical oceanic concentrations. Possibly as an adaptation to this chemical advantage marine animals typically can respond to external CO2 stress simply by metabolic adjustment. This is energetically more favorable than having to resort to mechanically increasing flow over their surface to thin the boundary layer as is required to alleviate O2 stress. Regionally as with O2 the combination of T, P, and pH/pCO2 creates a zone of maximum CO2 stress at around 1000 m depth. But the net result is that the combination of an increase in T combined with declining O2 poses a greater respiratory challenge to marine life than does increasing CO2. The relationships developed here allow a more accurate prediction of the impacts on marine life from the combined effects of changing T, O2, and CO2 than can be estimated from single variable studies.

Human health problems associated with current agricultural food production.

PubMed

Bhat, Ramesh V

2008-01-01

Scientific and technological developments in the agricultural sectors in the recent past has resulted in increased food production and at the same time led to certain public health concerns. Unseasonal rains at the time of harvest and improper post harvest technology often results in agricultural commodities being contaminated with certain fungi and results in the production of mycotoxins. Consumption of such commodities has resulted in human disease outbreaks. Naturally occurring toxins, inherently present in foods and either consumed as such or mixed up with grains, had been responsible for disease outbreaks. Other possible causes of health concern include the application of various agrochemicals such as pesticides and the use of antibiotics in aquaculture and veterinary practices. Foodborne pathogens entering the food chain during both traditional and organic agriculture pose a challenge to public health. Modern biotechnology, producing genetically modified foods, if not regulated appropriately could pose dangers to human health. Use of various integrated food management systems like the Hazard Analysis and critical control system approach for risk prevention, monitoring and control of food hazards are being emphasized with globalization to minimise the danger posed to human health from improper agricultural practices.

The VAST Challenge: History, Scope, and Outcomes: An introduction to the Special Issue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cook, Kristin A.; Grinstein, Georges; Whiting, Mark A.

2014-10-01

Visual analytics aims to facilitate human insight from complex data via a combination of visual representations, interaction techniques, and supporting algorithms. To create new tools and techniques that achieve this goal requires that researchers have an understanding of analytical questions to be addressed, data that illustrates the complexities and ambiguities found in realistic analytic settings, and methods for evaluating whether the plausible insights are gained through use of the new methods. However, researchers do not, generally speaking, have access to analysts who can articulate their problems or operational data that is used for analysis. To fill this gap, the Visualmore » Analytics Science and Technology (VAST) Challenge has been held annually since 2006. The VAST Challenge provides an opportunity for researchers to experiment with realistic but not real problems, using realistic synthetic data with known events embedded. Since its inception, the VAST Challenge has evolved along with the visual analytics research community to pose more complex challenges, ranging from text analysis to video analysis to large scale network log analysis. The seven years of the VAST Challenge have seen advancements in research and development, education, evaluation, and in the challenge process itself. This special issue of Information Visualization highlights some of the noteworthy advancements in each of these areas. Some of these papers focus on important research questions related to the challenge itself, and other papers focus on innovative research that has been shaped by participation in the challenge. This paper describes the VAST Challenge process and benefits in detail. It also provides an introduction to and context for the remaining papers in the issue.« less

Visual Reconciliation of Alternative Similarity Spaces in Climate Modeling.

PubMed

Poco, Jorge; Dasgupta, Aritra; Wei, Yaxing; Hargrove, William; Schwalm, Christopher R; Huntzinger, Deborah N; Cook, Robert; Bertini, Enrico; Silva, Claudio T

2014-12-01

Visual data analysis often requires grouping of data objects based on their similarity. In many application domains researchers use algorithms and techniques like clustering and multidimensional scaling to extract groupings from data. While extracting these groups using a single similarity criteria is relatively straightforward, comparing alternative criteria poses additional challenges. In this paper we define visual reconciliation as the problem of reconciling multiple alternative similarity spaces through visualization and interaction. We derive this problem from our work on model comparison in climate science where climate modelers are faced with the challenge of making sense of alternative ways to describe their models: one through the output they generate, another through the large set of properties that describe them. Ideally, they want to understand whether groups of models with similar spatio-temporal behaviors share similar sets of criteria or, conversely, whether similar criteria lead to similar behaviors. We propose a visual analytics solution based on linked views, that addresses this problem by allowing the user to dynamically create, modify and observe the interaction among groupings, thereby making the potential explanations apparent. We present case studies that demonstrate the usefulness of our technique in the area of climate science.

Optimizing care for the obese patient in interventional radiology

PubMed Central

Aberle, Dwight; Charles, Hearns; Hodak, Steven; O’Neill, Daniel; Oklu, Rahmi; Deipolyi, Amy R.

2017-01-01

With the rising epidemic of obesity, interventional radiologists are treating increasing numbers of obese patients, as comorbidities associated with obesity preclude more invasive treatments. These patients are at heightened risk of vascular and oncologic disease, both of which often require interventional radiology care. Obese patients pose unique challenges in imaging, technical feasibility, and periprocedural monitoring. This review describes the technical and clinical challenges posed by this population, with proposed methods to mitigate these challenges and optimize care. PMID:28082253

Building partnership capacity for the collaborative management of marine protected areas in the UK: a preliminary analysis.

PubMed

Jones, Peter J S; Burgess, Jacquelin

2005-11-01

This paper reports the findings of a preliminary analysis of 15 case studies of inshore marine protected areas in the UK. It draws on the common-pool resource (CPR) literature and is premised on the thesis that building partnership capacity amongst relevant authorities and resource users provides a critical basis for overcoming collective action problems (CAPs), through the development of incentive structures and social capital, in order to achieve strategic objectives. Particular attention is paid to the influence of statutory marine biodiversity conservation obligations to the European Commission for marine special areas of conservation (MSACs), as these are an important external contextual factor. The risks of imposition and parochialism are outlined and the challenges of taking a balanced approach are discussed. The challenges posed by the attributes of the marine environment are considered, as are those posed by the policy framework for MSACs. The findings are discussed in relation to three questions: (i) which partnership models appear to have the potential to overcome the CAPs posed by inshore MSACs? (ii) what CAPs had to be addressed during the early phase of development of the MSAC co-management regimes? (iii) what are the likely future CAPs for the collaborative management of MSACs that each partnership will need to address? These preliminary findings will form the basis for future studies to analyse the outcomes of these 15 initiatives, in order to assess the strengths, in various contexts, of different approaches for building resilient and balanced, thereby effective, institutions for the co-management of MSACs in the UK.

Towards Modeling False Memory With Computational Knowledge Bases.

PubMed

Li, Justin; Kohanyi, Emma

2017-01-01

One challenge to creating realistic cognitive models of memory is the inability to account for the vast common-sense knowledge of human participants. Large computational knowledge bases such as WordNet and DBpedia may offer a solution to this problem but may pose other challenges. This paper explores some of these difficulties through a semantic network spreading activation model of the Deese-Roediger-McDermott false memory task. In three experiments, we show that these knowledge bases only capture a subset of human associations, while irrelevant information introduces noise and makes efficient modeling difficult. We conclude that the contents of these knowledge bases must be augmented and, more important, that the algorithms must be refined and optimized, before large knowledge bases can be widely used for cognitive modeling. Copyright © 2016 Cognitive Science Society, Inc.

A Domain Description Language for Data Processing

NASA Technical Reports Server (NTRS)

Golden, Keith

2003-01-01

We discuss an application of planning to data processing, a planning problem which poses unique challenges for domain description languages. We discuss these challenges and why the current PDDL standard does not meet them. We discuss DPADL (Data Processing Action Description Language), a language for describing planning domains that involve data processing. DPADL is a declarative, object-oriented language that supports constraints and embedded Java code, object creation and copying, explicit inputs and outputs for actions, and metadata descriptions of existing and desired data. DPADL is supported by the IMAGEbot system, which we are using to provide automation for an ecological forecasting application. We compare DPADL to PDDL and discuss changes that could be made to PDDL to make it more suitable for representing planning domains that involve data processing actions.

[The aging of the population and late-life depression--implications for the medical sciences and presentation of one therapeutic modality].

PubMed

Soref, Erez

2007-01-01

This short article attempts to describe and review one of the most significant demographic phenomena in recent and upcoming decades namely the aging of the population, and discuss some of its implications for public health policies in Israel. The absolute and relative growth of the elderly proportion in the population poses a challenge in many respects, one aspect of which is in the field of mental health. The number one psychiatric problem in later life is late-life depression. Following a clinical and epidemiological review of late-life depression, a review of one specific treatment modality is presented - partial psychiatric hospitalization. This discussion is timely in light of the upcoming challenge of managed care in Israel's public mental health system.

Wavelet methods in multi-conjugate adaptive optics

NASA Astrophysics Data System (ADS)

Helin, T.; Yudytskiy, M.

2013-08-01

The next generation ground-based telescopes rely heavily on adaptive optics for overcoming the limitation of atmospheric turbulence. In the future adaptive optics modalities, like multi-conjugate adaptive optics (MCAO), atmospheric tomography is the major mathematical and computational challenge. In this severely ill-posed problem, a fast and stable reconstruction algorithm is needed that can take into account many real-life phenomena of telescope imaging. We introduce a novel reconstruction method for the atmospheric tomography problem and demonstrate its performance and flexibility in the context of MCAO. Our method is based on using locality properties of compactly supported wavelets, both in the spatial and frequency domains. The reconstruction in the atmospheric tomography problem is obtained by solving the Bayesian MAP estimator with a conjugate-gradient-based algorithm. An accelerated algorithm with preconditioning is also introduced. Numerical performance is demonstrated on the official end-to-end simulation tool OCTOPUS of European Southern Observatory.

Simulation and optimization of an experimental membrane wastewater treatment plant using computational intelligence methods.

PubMed

Ludwig, T; Kern, P; Bongards, M; Wolf, C

2011-01-01

The optimization of relaxation and filtration times of submerged microfiltration flat modules in membrane bioreactors used for municipal wastewater treatment is essential for efficient plant operation. However, the optimization and control of such plants and their filtration processes is a challenging problem due to the underlying highly nonlinear and complex processes. This paper presents the use of genetic algorithms for this optimization problem in conjunction with a fully calibrated simulation model, as computational intelligence methods are perfectly suited to the nonconvex multi-objective nature of the optimization problems posed by these complex systems. The simulation model is developed and calibrated using membrane modules from the wastewater simulation software GPS-X based on the Activated Sludge Model No.1 (ASM1). Simulation results have been validated at a technical reference plant. They clearly show that filtration process costs for cleaning and energy can be reduced significantly by intelligent process optimization.

Shared Activity Coordination

NASA Technical Reports Server (NTRS)

Clement, Bradley J.; Barrett, Anthony C.

2003-01-01

Interacting agents that interleave planning and execution must reach consensus on their commitments to each other. In domains where agents have varying degrees of interaction and different constraints on communication and computation, agents will require different coordination protocols in order to efficiently reach consensus in real time. We briefly describe a largely unexplored class of real-time, distributed planning problems (inspired by interacting spacecraft missions), new challenges they pose, and a general approach to solving the problems. These problems involve self-interested agents that have infrequent communication but collaborate on joint activities. We describe a Shared Activity Coordination (SHAC) framework that provides a decentralized algorithm for negotiating the scheduling of shared activities in a dynamic environment, a soft, real-time approach to reaching consensus during execution with limited communication, and a foundation for customizing protocols for negotiating planner interactions. We apply SHAC to a realistic simulation of interacting Mars missions and illustrate the simplicity of protocol development.

Continual coordination through shared activities

NASA Technical Reports Server (NTRS)

Clement, Bradley J.; Barrett, Anthony C.

2003-01-01

Interacting agents that interleave planning and execution must reach consensus on their commitments to each other. In domains where agents have varying degrees of interaction and different constraints on communication and computation, agents will require different coordination protocols in order to efficiently reach consensus in real time. We briefly describe a largely unexplored class of realtime, distributed planning problems (inspired by interacting spacecraft missions), new challenges they pose, and a general approach to solving the problems. These problems involve self-interested agents that have infrequent communication but collaborate on joint activities. We describe a Shared Activity Coordination (SHAC) framework that provides a decentralized algorithm for negotiating the scheduling of shared activities over the lifetimes of separate missions, a soft, real-time approach to reaching consensus during execution with limited communication, and a foundation for customizing protocols for negotiating planner interactions. We apply SHAC to a realistic simulation of interacting Mars missions and illustrate the simplicity of protocol development.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scribner, R.A.

Sea-launched cruise missiles (SLCMs) present some particularly striking problems for both national security and arms control. These small, dual-purpose, difficult to detect weapons present some formidable challenges for verification in any scheme that attempts to limit rather than eliminate them. Conventionally armed SLCMs offer to the navies of both superpowers important offensive and defensive capabilities. Nuclear armed, long-range, land-attack SLCMs, on the other hand, seem to pose destabilizing threats and otherwise have questionable value, despite strong US support for extensive deployment of them. If these weapons are not constrained, their deployment could circumvent gains which might be made in agreementsmore » directly reducing of strategic nuclear weapons. This paper reviews the technology and planned deployments of SLCMs, the verification schemes which have been discussed and are being investigated to try to deal with the problem, and examines the proposed need for and possible uses of SLCMs. It presents an overview of the problem technically, militarily, and politically.« less

A Complete OCR System for Tamil Magazine Documents

NASA Astrophysics Data System (ADS)

Kokku, Aparna; Chakravarthy, Srinivasa

We present a complete optical character recognition (OCR) system for Tamil magazines/documents. All the standard elements of OCR process like de-skewing, preprocessing, segmentation, character recognition, and reconstruction are implemented. Experience with OCR problems teaches that for most subtasks of OCR, there is no single technique that gives perfect results for every type of document image. We exploit the ability of neural networks to learn from experience in solving the problems of segmentation and character recognition. Text segmentation of Tamil newsprint poses a new challenge owing to its italic-like font type; problems that arise in recognition of touching and close characters are discussed. Character recognition efficiency varied from 94 to 97% for this type of font. The grouping of blocks into logical units and the determination of reading order within each logical unit helped us in reconstructing automatically the document image in an editable format.

Calculation of susceptibility through multiple orientation sampling (COSMOS): a method for conditioning the inverse problem from measured magnetic field map to susceptibility source image in MRI.

PubMed

Liu, Tian; Spincemaille, Pascal; de Rochefort, Ludovic; Kressler, Bryan; Wang, Yi

2009-01-01

Magnetic susceptibility differs among tissues based on their contents of iron, calcium, contrast agent, and other molecular compositions. Susceptibility modifies the magnetic field detected in the MR signal phase. The determination of an arbitrary susceptibility distribution from the induced field shifts is a challenging, ill-posed inverse problem. A method called "calculation of susceptibility through multiple orientation sampling" (COSMOS) is proposed to stabilize this inverse problem. The field created by the susceptibility distribution is sampled at multiple orientations with respect to the polarization field, B(0), and the susceptibility map is reconstructed by weighted linear least squares to account for field noise and the signal void region. Numerical simulations and phantom and in vitro imaging validations demonstrated that COSMOS is a stable and precise approach to quantify a susceptibility distribution using MRI.

The Analysis of the Problems the Pre-Service Teachers Experience in Posing Problems about Equations

ERIC Educational Resources Information Center

Isik, Cemalettin; Kar, Tugrul

2012-01-01

The present study aimed to analyse the potential difficulties in the problems posed by pre-service teachers about first degree equations with one unknown and equation pairs with two unknowns. It was carried out with 20 pre-service teachers studying in the Department of Elementary Mathematics Educations at a university in Eastern Turkey. The…

Control and System Theory, Optimization, Inverse and Ill-Posed Problems

DTIC Science & Technology

1988-09-14

Justlfleatlen Distribut ion/ Availability Codes # AFOSR-87-0350 Avat’ and/or1987-1988 Dist Special *CONTROL AND SYSTEM THEORY , ~ * OPTIMIZATION, * INVERSE...considerable va- riety of research investigations within the grant areas (Control and system theory , Optimization, and Ill-posed problems]. The

D3R grand challenge 2015: Evaluation of protein-ligand pose and affinity predictions

NASA Astrophysics Data System (ADS)

Gathiaka, Symon; Liu, Shuai; Chiu, Michael; Yang, Huanwang; Stuckey, Jeanne A.; Kang, You Na; Delproposto, Jim; Kubish, Ginger; Dunbar, James B.; Carlson, Heather A.; Burley, Stephen K.; Walters, W. Patrick; Amaro, Rommie E.; Feher, Victoria A.; Gilson, Michael K.

2016-09-01

The Drug Design Data Resource (D3R) ran Grand Challenge 2015 between September 2015 and February 2016. Two targets served as the framework to test community docking and scoring methods: (1) HSP90, donated by AbbVie and the Community Structure Activity Resource (CSAR), and (2) MAP4K4, donated by Genentech. The challenges for both target datasets were conducted in two stages, with the first stage testing pose predictions and the capacity to rank compounds by affinity with minimal structural data; and the second stage testing methods for ranking compounds with knowledge of at least a subset of the ligand-protein poses. An additional sub-challenge provided small groups of chemically similar HSP90 compounds amenable to alchemical calculations of relative binding free energy. Unlike previous blinded Challenges, we did not provide cognate receptors or receptors prepared with hydrogens and likewise did not require a specified crystal structure to be used for pose or affinity prediction in Stage 1. Given the freedom to select from over 200 crystal structures of HSP90 in the PDB, participants employed workflows that tested not only core docking and scoring technologies, but also methods for addressing water-mediated ligand-protein interactions, binding pocket flexibility, and the optimal selection of protein structures for use in docking calculations. Nearly 40 participating groups submitted over 350 prediction sets for Grand Challenge 2015. This overview describes the datasets and the organization of the challenge components, summarizes the results across all submitted predictions, and considers broad conclusions that may be drawn from this collaborative community endeavor.

D3R Grand Challenge 2015: Evaluation of Protein-Ligand Pose and Affinity Predictions

PubMed Central

Gathiaka, Symon; Liu, Shuai; Chiu, Michael; Yang, Huanwang; Stuckey, Jeanne A; Kang, You Na; Delproposto, Jim; Kubish, Ginger; Dunbar, James B.; Carlson, Heather A.; Burley, Stephen K.; Walters, W. Patrick; Amaro, Rommie E.; Feher, Victoria A.; Gilson, Michael K.

2017-01-01

The Drug Design Data Resource (D3R) ran Grand Challenge 2015 between September 2015 and February 2016. Two targets served as the framework to test community docking and scoring methods: (i) HSP90, donated by AbbVie and the Community Structure Activity Resource (CSAR), and (ii) MAP4K4, donated by Genentech. The challenges for both target datasets were conducted in two stages, with the first stage testing pose predictions and the capacity to rank compounds by affinity with minimal structural data; and the second stage testing methods for ranking compounds with knowledge of at least a subset of the ligand-protein poses. An additional sub-challenge provided small groups of chemically similar HSP90 compounds amenable to alchemical calculations of relative binding free energy. Unlike previous blinded Challenges, we did not provide cognate receptors or receptors prepared with hydrogens and likewise did not require a specified crystal structure to be used for pose or affinity prediction in Stage 1. Given the freedom to select from over 200 crystal structures of HSP90 in the PDB, participants employed workflows that tested not only core docking and scoring technologies, but also methods for addressing water-mediated ligand-protein interactions, binding pocket flexibility, and the optimal selection of protein structures for use in docking calculations. Nearly 40 participating groups submitted over 350 prediction sets for Grand Challenge 2015. This overview describes the datasets and the organization of the challenge components, summarizes the results across all submitted predictions, and considers broad conclusions that may be drawn from this collaborative community endeavor. PMID:27696240

Confronting Decision Cliffs: Diagnostic Assessment of Multi-Objective Evolutionary Algorithms' Performance for Addressing Uncertain Environmental Thresholds

NASA Astrophysics Data System (ADS)

Ward, V. L.; Singh, R.; Reed, P. M.; Keller, K.

2014-12-01

As water resources problems typically involve several stakeholders with conflicting objectives, multi-objective evolutionary algorithms (MOEAs) are now key tools for understanding management tradeoffs. Given the growing complexity of water planning problems, it is important to establish if an algorithm can consistently perform well on a given class of problems. This knowledge allows the decision analyst to focus on eliciting and evaluating appropriate problem formulations. This study proposes a multi-objective adaptation of the classic environmental economics "Lake Problem" as a computationally simple but mathematically challenging MOEA benchmarking problem. The lake problem abstracts a fictional town on a lake which hopes to maximize its economic benefit without degrading the lake's water quality to a eutrophic (polluted) state through excessive phosphorus loading. The problem poses the challenge of maintaining economic activity while confronting the uncertainty of potentially crossing a nonlinear and potentially irreversible pollution threshold beyond which the lake is eutrophic. Objectives for optimization are maximizing economic benefit from lake pollution, maximizing water quality, maximizing the reliability of remaining below the environmental threshold, and minimizing the probability that the town will have to drastically change pollution policies in any given year. The multi-objective formulation incorporates uncertainty with a stochastic phosphorus inflow abstracting non-point source pollution. We performed comprehensive diagnostics using 6 algorithms: Borg, MOEAD, eMOEA, eNSGAII, GDE3, and NSGAII to ascertain their controllability, reliability, efficiency, and effectiveness. The lake problem abstracts elements of many current water resources and climate related management applications where there is the potential for crossing irreversible, nonlinear thresholds. We show that many modern MOEAs can fail on this test problem, indicating its suitability as a useful and nontrivial benchmarking problem.

The World in a Tomato: Revisiting the Use of "Codes" in Freire's Problem-Posing Education.

ERIC Educational Resources Information Center

Barndt, Deborah

1998-01-01

Gives examples of the use of Freire's notion of codes or generative themes in problem-posing literacy education. Describes how these applications expand Freire's conceptions by involving students in code production, including multicultural perspectives, and rethinking codes as representations. (SK)

Evidence-based medicine and the development of medical libraries in China.

PubMed

Huang, Michael Bailou; Cheng, Aijun; Ma, Lu

2009-07-01

This article elaborates on the opportunities and challenges that evidence-based medicine (EBM) has posed to the development of medical libraries and summarizes the research in the field of evidence-based medicine and achievements of EBM practice in Chinese medical libraries. Issues such as building collections of information resources, transformation of information services models, human resources management, and training of medical librarians, clinicians, and EBM users are addressed. In view of problems encountered in EBM research and practice, several suggestions are made about important roles medical libraries can play in the future development of EBM in China.

Decentralization, democratization, and health: the Philippine experiment.

PubMed

Langran, Irene V

2011-01-01

In 1991, the Philippines joined a growing list of countries that reformed health planning through decentralization. Reformers viewed decentralization as a tool that would solve multiple problems, leading to more meaningful democracy and more effective health planning. Today, nearly two decades after the passage of decentralization legislation, questions about the effectiveness of the reforms persist. Inadequate financing, inequity, and a lack of meaningful participation remain challenges, in many ways mirroring broader weaknesses of Philippine democracy. These concerns pose questions regarding the nature of contemporary decentralization, democratization, and health planning and whether these three strategies are indeed mutually enforcing.

Quantitative performance measurements of bent crystal Laue analyzers for X-ray fluorescence spectroscopy.

PubMed

Karanfil, C; Bunker, G; Newville, M; Segre, C U; Chapman, D

2012-05-01

Third-generation synchrotron radiation sources pose difficult challenges for energy-dispersive detectors for XAFS because of their count rate limitations. One solution to this problem is the bent crystal Laue analyzer (BCLA), which removes most of the undesired scatter and fluorescence before it reaches the detector, effectively eliminating detector saturation due to background. In this paper experimental measurements of BCLA performance in conjunction with a 13-element germanium detector, and a quantitative analysis of the signal-to-noise improvement of BCLAs are presented. The performance of BCLAs are compared with filters and slits.

Space artificial gravity facilities - An approach to their construction

NASA Technical Reports Server (NTRS)

Wercinski, P. F.; Searby, N. D.; Tillman, B. W.

1988-01-01

In the course of adaptation to a space microgravity environment, humans experience cardiovascular deconditioning, loss of muscle mass, and loss of bone minerals. One possible solution to these space adaptation problems is to simulate earth's gravity using the centripetal acceleration created by a rotating system. The design and construction of rotating space structures pose many challenges. Before committing to the use of artificial gravity in future space missions, a man-rated Variable Gravity Research Facility (VGRF) should be developed in earth orbit as a gravitational research tool and testbed. This paper addresses the requirements and presents preliminary concepts for such a facility.

Current and emerging global themes in the bioethics of regenerative medicine: the tangled web of stem cell translation.

PubMed

Chan, Sarah

2017-10-01

Probably the most serious problem facing the field of regenerative medicine today is the challenge of effective translation and development of viable stem cell-based therapies. Particular concerns have been raised over the growing market in unproven cell therapies. In this article, I explore recent developments in the stem cell therapy landscape and argue that while the sale of unproven therapies undoubtedly poses ethical concerns, it must be understood as part of a larger problem at the interface between biomedicine, healthcare, publics, policy and the market. Addressing this will require a broader perspective incorporating the shifting relationships between different stakeholder groups, the global politics of research and innovation, and the evolving role of publics and patients with respect to science.

Urinary tract infections in pregnancy: old and new unresolved diagnostic and therapeutic problems.

PubMed

Matuszkiewicz-Rowińska, Joanna; Małyszko, Jolanta; Wieliczko, Monika

2015-03-16

Urinary tract infections (UTIs) are common in pregnant women and pose a great therapeutic challenge, since the risk of serious complications in both the mother and her child is high. Pregnancy is a state associated with physiological, structural and functional urinary tract changes which promote ascending infections from the urethra. Unlike the general population, all pregnant women should be screened for bacteriuria with urine culture, and asymptomatic bacteriuria must be treated in every case that is diagnosed, as it is an important risk factor for pyelonephritis in this population. The antibiotic chosen should have a good maternal and fetal safety profile. In this paper, current principles of diagnosis and management of UTI in pregnancy are reviewed, and the main problems and controversies are identified and discussed.

Current and emerging global themes in the bioethics of regenerative medicine: the tangled web of stem cell translation

PubMed Central

Chan, Sarah

2017-01-01

Probably the most serious problem facing the field of regenerative medicine today is the challenge of effective translation and development of viable stem cell-based therapies. Particular concerns have been raised over the growing market in unproven cell therapies. In this article, I explore recent developments in the stem cell therapy landscape and argue that while the sale of unproven therapies undoubtedly poses ethical concerns, it must be understood as part of a larger problem at the interface between biomedicine, healthcare, publics, policy and the market. Addressing this will require a broader perspective incorporating the shifting relationships between different stakeholder groups, the global politics of research and innovation, and the evolving role of publics and patients with respect to science. PMID:29119870

Urinary tract infections in pregnancy: old and new unresolved diagnostic and therapeutic problems

PubMed Central

Małyszko, Jolanta; Wieliczko, Monika

2015-01-01

Urinary tract infections (UTIs) are common in pregnant women and pose a great therapeutic challenge, since the risk of serious complications in both the mother and her child is high. Pregnancy is a state associated with physiological, structural and functional urinary tract changes which promote ascending infections from the urethra. Unlike the general population, all pregnant women should be screened for bacteriuria with urine culture, and asymptomatic bacteriuria must be treated in every case that is diagnosed, as it is an important risk factor for pyelonephritis in this population. The antibiotic chosen should have a good maternal and fetal safety profile. In this paper, current principles of diagnosis and management of UTI in pregnancy are reviewed, and the main problems and controversies are identified and discussed. PMID:25861291

Deep Learning for Computer Vision: A Brief Review

PubMed Central

Doulamis, Nikolaos; Doulamis, Anastasios; Protopapadakis, Eftychios

2018-01-01

Over the last years deep learning methods have been shown to outperform previous state-of-the-art machine learning techniques in several fields, with computer vision being one of the most prominent cases. This review paper provides a brief overview of some of the most significant deep learning schemes used in computer vision problems, that is, Convolutional Neural Networks, Deep Boltzmann Machines and Deep Belief Networks, and Stacked Denoising Autoencoders. A brief account of their history, structure, advantages, and limitations is given, followed by a description of their applications in various computer vision tasks, such as object detection, face recognition, action and activity recognition, and human pose estimation. Finally, a brief overview is given of future directions in designing deep learning schemes for computer vision problems and the challenges involved therein. PMID:29487619

Vision Based SLAM in Dynamic Scenes

DTIC Science & Technology

2012-12-20

the correct relative poses between cameras at frame F. For this purpose, we detect and match SURF features between cameras in dilierent groups, and...all cameras in s uch a challenging case. For a compa rison, we disabled the ’ inte r-camera pose estimation’ and applied the ’ intra-camera pose esti

Assessment of a Problem Posing Task in a Jamaican Grade Four Mathematics Classroom

ERIC Educational Resources Information Center

Munroe, Kayan Lloyd

2016-01-01

This paper analyzes how a teacher of mathematics used problem posing in the assessment of the cognitive development of 26 students at the grade-four level. The students, ages 8 to 10 years, were from a rural elementary school in western Jamaica. Using a picture as a prompt, students were asked to generate three arithmetic problems and to offer…

Simultaneous branchial cleft and thyroid disorders may present a management challenge.

PubMed

Harding, Jane L; Veivers, David; Sidhu, Stan B; Sywak, Mark S; Shun, Albert; Delbridge, Leigh W

2005-09-01

Cysts, sinuses or abscesses arising from second, third or fourth branchial cleft remnants may lie either within the body of, or in close proximity to the thyroid gland. Given their infrequent nature they may pose both diagnostic and management challenges for the treating surgeon when they occur in association with thyroid disorders. This is a case series. All patients with concomitant thyroid disorders and a branchial cleft anomaly treated in the University of Sydney Endocrine Surgical Unit in the 10-year period 1994-2003 comprised the study group. Patient demographics, clinical presentation, imaging, surgical management, definitive histology and outcomes were documented. Six patients were identified with an age range of 3-76 years and a male : female ratio of 1:5. Five branchial cleft anomalies were left sided, one was right sided. Two patients had second cleft anomalies, both of which were initially thought to represent metastatic lymph nodes in association with thyroid cancer. A further two patients had third cleft abnormalities presenting as suppurative thyroiditis. The final two patients had fourth cleft abnormalities causing intraoperative management problems. Branchial cleft remnants and anomalies are rare but may occur in association with thyroid disease. They may pose a diagnostic and management dilemma either preoperatively, when mistaken for metastatic thyroid cancer, or intraoperatively when mistaken for a thyroid nodule.

A novel architecture for information retrieval system based on semantic web

NASA Astrophysics Data System (ADS)

Zhang, Hui

2011-12-01

Nowadays, the web has enabled an explosive growth of information sharing (there are currently over 4 billion pages covering most areas of human endeavor) so that the web has faced a new challenge of information overhead. The challenge that is now before us is not only to help people locating relevant information precisely but also to access and aggregate a variety of information from different resources automatically. Current web document are in human-oriented formats and they are suitable for the presentation, but machines cannot understand the meaning of document. To address this issue, Berners-Lee proposed a concept of semantic web. With semantic web technology, web information can be understood and processed by machine. It provides new possibilities for automatic web information processing. A main problem of semantic web information retrieval is that when these is not enough knowledge to such information retrieval system, the system will return to a large of no sense result to uses due to a huge amount of information results. In this paper, we present the architecture of information based on semantic web. In addiction, our systems employ the inference Engine to check whether the query should pose to Keyword-based Search Engine or should pose to the Semantic Search Engine.

Mathematical Thinking and Creativity through Mathematical Problem Posing and Solving

ERIC Educational Resources Information Center

Ayllón, María F.; Gómez, Isabel A.; Ballesta-Claver, Julio

2016-01-01

This work shows the relationship between the development of mathematical thinking and creativity with mathematical problem posing and solving. Creativity and mathematics are disciplines that do not usually appear together. Both concepts constitute complex processes sharing elements, such as fluency (number of ideas), flexibility (range of ideas),…

Problem Posing Based on Investigation Activities by University Students

ERIC Educational Resources Information Center

da Ponte, Joao Pedro; Henriques, Ana

2013-01-01

This paper reports a classroom-based study involving investigation activities in a university numerical analysis course. The study aims to analyse students' mathematical processes and to understand how these activities provide opportunities for problem posing. The investigations were intended to stimulate students in asking questions, to trigger…

Examining Mathematics Classroom Interactions: Elevating Student Roles in Teaching and Learning

ERIC Educational Resources Information Center

Kent, Laura

2017-01-01

This article introduces a model entitled, "Responsive Teaching through Problem Posing" or RTPP, that addresses a type of reform oriented mathematics teaching based on posing relevant problems, positioning students as experts of mathematics, and facilitating discourse. RTPP incorporates decades of research on students' thinking in…

Rethinking Global Water Governance for the 21st Century

NASA Astrophysics Data System (ADS)

Ajami, N. K.; Cooley, H.

2012-12-01

Growing pressure on the world's water resources is having major impacts on our social and economic well-being. According to the United Nations, today, at least 1.1 billion people do not have access to clean drinking water. Pressures on water resources are likely to continue to worsen in response to decaying and crumbling infrastructure, continued population growth, climate change, degradation of water quality, and other challenges. If these challenges are not addressed, they pose future risks for many countries around the world, making it urgent that efforts are made to understand both the nature of the problems and the possible solutions that can effectively reduce the associated risks. There is growing understanding of the need to rethink governance to meet the 21st century water challenges. More and more water problems extend over traditional national boundaries and to the global community and the types and numbers of organizations addressing water issues are large and growing. Economic globalization and transnational organizations and activities point to the need for improving coordination and integration on addressing water issues, which are increasingly tied to food and energy security, trade, global climate change, and other international policies. We will present some of the key limitations of global water governance institutions and provide recommendations for improving these institutions to address 21st century global water challenges more effectively.

Easier said than done: challenges of applying the Ecohealth approach to the study on heavy metals exposure among indigenous communities of the Peruvian Amazon

PubMed Central

2013-01-01

Background The renewed interest in community participation in health research is linked to its potential for bridging gaps between research and practice. Its main attributes are the generation of knowledge that can lead to socially robust, long-lasting solutions and the creation of a co-learner relationship between researchers and research users. Following this philosophy, Ecohealth has evolved into a specialized framework for participatory research on the impact of pollution on ecosystems and human health. However, its principles pose considerable challenges. Its outcomes are strongly influenced by contextual factors that are impossible to control for ahead of time. This paper describes how the Ecohealth principles were applied to an epidemiological study of heavy metals exposure among indigenous communities of the Peruvian Amazon. It illustrates how knowledge generated from participatory research does not necessarily imply solving a public health problem. This study aimed to contribute to the understanding of the benefits and barriers of following the basic principles of the Ecohealth approach, and assist researchers working in similar contexts. Research process Based upon their personal experience as participant observers, the authors describe the research process; then, they discuss the most important challenges faced, their implications, and the attempted strategies for resolution. Challenges Challenges were grouped into four themes: (1) building trust; (2) one partnership, many stakeholders, multiple agendas; (3) being a researcher; and (4) communicating complex and unexpected findings. Conclusions Integrating the principles of transdisciplinarity and participation posed a series of challenges to the research process that were difficult, and sometimes impossible to overcome. However, positive outcomes from this experience were the lessons learned by the different actors. Despite the lack of immediate action, it is expected that useful interventions to prevent and control lead exposure in the Corrientes population will be implemented in the medium term. PMID:23642035

Clone tag detection in distributed RFID systems.

PubMed

Kamaludin, Hazalila; Mahdin, Hairulnizam; Abawajy, Jemal H

2018-01-01

Although Radio Frequency Identification (RFID) is poised to displace barcodes, security vulnerabilities pose serious challenges for global adoption of the RFID technology. Specifically, RFID tags are prone to basic cloning and counterfeiting security attacks. A successful cloning of the RFID tags in many commercial applications can lead to many serious problems such as financial losses, brand damage, safety and health of the public. With many industries such as pharmaceutical and businesses deploying RFID technology with a variety of products, it is important to tackle RFID tag cloning problem and improve the resistance of the RFID systems. To this end, we propose an approach for detecting cloned RFID tags in RFID systems with high detection accuracy and minimal overhead thus overcoming practical challenges in existing approaches. The proposed approach is based on consistency of dual hash collisions and modified count-min sketch vector. We evaluated the proposed approach through extensive experiments and compared it with existing baseline approaches in terms of execution time and detection accuracy under varying RFID tag cloning ratio. The results of the experiments show that the proposed approach outperforms the baseline approaches in cloned RFID tag detection accuracy.

Commercial influence and global nongovernmental public action in health and pharmaceutical policies.

PubMed

Koivusalo, Meri; Mackintosh, Maureen

2011-01-01

Nongovernmental public action has been effective in influencing global agenda-setting in health and pharmaceutical policies, yet its record in influencing solutions to the problems identified has been notably more limited. While trade policies have been particularly resistant to change, more substantial changes are observable in global health policies and global health governance. However, some of the directions of change may not be conducive to the democratic accountability of global health governance, to the wise use of public resources, to health systems development, or to longer-term access to health care within developing countries. The authors argue that observed changes in global health policies can be understood as accommodating to corporate concerns and priorities. Furthermore, the changing global context and the commercialization of global public action itself pose sharp challenges to the exercise of influence by global nongovernmental public actors. Nongovernmental organizations not only face a major challenge in terms of the imbalance in power and resources between themselves and corporate interest groups when seeking to influence policymaking; they also face the problem of corporate influence on public action itself.

Stable architectures for deep neural networks

NASA Astrophysics Data System (ADS)

Haber, Eldad; Ruthotto, Lars

2018-01-01

Deep neural networks have become invaluable tools for supervised machine learning, e.g. classification of text or images. While often offering superior results over traditional techniques and successfully expressing complicated patterns in data, deep architectures are known to be challenging to design and train such that they generalize well to new data. Critical issues with deep architectures are numerical instabilities in derivative-based learning algorithms commonly called exploding or vanishing gradients. In this paper, we propose new forward propagation techniques inspired by systems of ordinary differential equations (ODE) that overcome this challenge and lead to well-posed learning problems for arbitrarily deep networks. The backbone of our approach is our interpretation of deep learning as a parameter estimation problem of nonlinear dynamical systems. Given this formulation, we analyze stability and well-posedness of deep learning and use this new understanding to develop new network architectures. We relate the exploding and vanishing gradient phenomenon to the stability of the discrete ODE and present several strategies for stabilizing deep learning for very deep networks. While our new architectures restrict the solution space, several numerical experiments show their competitiveness with state-of-the-art networks.

Searching for Authentic Context in Designing PISA-like Mathematics Problem: From Indoor to Outdoor Field Experience

NASA Astrophysics Data System (ADS)

Siswono, T. Y. E.; Kohar, A. W.; Rosyidi, A. H.; Hartono, S.; Masriyah

2018-01-01

Designing problem like in PISA is known as a challenging activity for teachers particularly as the use of authentic context within that type of problem. This paper aims to describe the experiences of secondary mathematics teachers in designing PISA-like problems within an innovative training program focusing on building teachers’ understanding on the concept of mathematical literacy. The teachers were engaged in a set of problem-solving and problem-posing activities using PISA-based problem within indoor and outdoor field experiences. Within indoor field experience, the teachers worked collaboratively in groups on designing PISA-like problems with a given context through problem generation and reformulation techniques. Within outdoor field experience, they worked on designing PISA-like problems with self-chosen context from the place where the outdoor field experience took place. Our analysis indicates that there were improvements on the PISA-like problems designed by teachers based on its level use of context from indoor to outdoor experience. Also, the teachers were relatively successful with creating appropriate and motivating contexts by harnessing a variety of context consisting of personal, occupational, societal, and scientific contexts. However, they still experienced difficulties in turning these contexts into an appropriate problem satisfying PISA framework such as regarding authenticity of context use, language structure, and PISA task profile.

Ways of Thinking Associated with Mathematics Teachers' Problem Posing in the Context of Division of Fractions

ERIC Educational Resources Information Center

Koichu, Boris; Harel, Guershon; Manaster, Alfred

2013-01-01

Twenty-four mathematics teachers were asked to think aloud when posing a word problem whose solution could be found by computing 4/5 divided by 2/3. The data consisted of verbal protocols along with the written notes made by the subjects. The qualitative analysis of the data was focused on identifying the structures of the problems produced and…

Hydrodynamics of wet foams

NASA Astrophysics Data System (ADS)

Langevin, Dominique; Saint-Jalmes, Arnaud; Marze, Sébastien; Cox, Simon; Hutzler, Stefan; Drenckhan, Wiebke; Weaire, Denis; Caps, Hervé; Vandewalle, Nicolas; Adler, Micheàle; Pitois, Olivier; Rouyer, Florence; Cohen-Addad, Sylvie; Höhler, Reinhard; Ritacco, Hernan

2005-10-01

Foams and foaming pose important questions and problems to the chemical industry. As a material, foam is unusual in being a desired product while also being an unwanted byproduct within industry. Liquid foams are an essential part of gas/liquid contacting processes such as distillation and absorption, but over-production of foam in these processes can lead to downtime and loss of efficiency. Solid polymeric foams, such as polystyrene and polyurethane, find applications as insulation panels in the construction industry. Their combination of low weight and unique elastic/plastic properties make them ideal as packing and cushioning materials. Foams made with proteins are extensively used in the food industry. Despite the fact that foam science is a rapidly maturing field, critical aspects of foam physics and chemistry remain unclear. Several gaps in knowledge were identified to be tackled as the core of this MAP project. In addition, microgravity affords conditions for extending our understanding far beyond the possibilities offered by ground-based investigation. This MAP project addresses the challenges posed by the physics of foams under microgravity.

Combining facial dynamics with appearance for age estimation.

PubMed

Dibeklioglu, Hamdi; Alnajar, Fares; Ali Salah, Albert; Gevers, Theo

2015-06-01

Estimating the age of a human from the captured images of his/her face is a challenging problem. In general, the existing approaches to this problem use appearance features only. In this paper, we show that in addition to appearance information, facial dynamics can be leveraged in age estimation. We propose a method to extract and use dynamic features for age estimation, using a person's smile. Our approach is tested on a large, gender-balanced database with 400 subjects, with an age range between 8 and 76. In addition, we introduce a new database on posed disgust expressions with 324 subjects in the same age range, and evaluate the reliability of the proposed approach when used with another expression. State-of-the-art appearance-based age estimation methods from the literature are implemented as baseline. We demonstrate that for each of these methods, the addition of the proposed dynamic features results in statistically significant improvement. We further propose a novel hierarchical age estimation architecture based on adaptive age grouping. We test our approach extensively, including an exploration of spontaneous versus posed smile dynamics, and gender-specific age estimation. We show that using spontaneity information reduces the mean absolute error by up to 21%, advancing the state of the art for facial age estimation.

Distributed Parallel Processing and Dynamic Load Balancing Techniques for Multidisciplinary High Speed Aircraft Design

NASA Technical Reports Server (NTRS)

Krasteva, Denitza T.

1998-01-01

Multidisciplinary design optimization (MDO) for large-scale engineering problems poses many challenges (e.g., the design of an efficient concurrent paradigm for global optimization based on disciplinary analyses, expensive computations over vast data sets, etc.) This work focuses on the application of distributed schemes for massively parallel architectures to MDO problems, as a tool for reducing computation time and solving larger problems. The specific problem considered here is configuration optimization of a high speed civil transport (HSCT), and the efficient parallelization of the embedded paradigm for reasonable design space identification. Two distributed dynamic load balancing techniques (random polling and global round robin with message combining) and two necessary termination detection schemes (global task count and token passing) were implemented and evaluated in terms of effectiveness and scalability to large problem sizes and a thousand processors. The effect of certain parameters on execution time was also inspected. Empirical results demonstrated stable performance and effectiveness for all schemes, and the parametric study showed that the selected algorithmic parameters have a negligible effect on performance.

Management of behavioral dysfunction: a corporate physician's perspective.

PubMed

Farid, I

1996-01-01

This chapter outlines the processes that engage the corporate physician in the course of the management and disposition of psychiatric problems. It begins with a description of a subprocess in which the physician adapts to working with nonmedical professionals as a member of a team. Much of the work lies outside the scope of medical practice and in the domain of management. Transition from the traditional role to a medical manager is an incremental learning process that prepares the physician to assimilate into his or her calculus organizational structure, dynamics, and culture. The core processes involved in the management of psychiatric problems are presented. These run the gamut on one end from the initial screening for psychiatric disorders at the time of placement to, at the other end, psychiatric disability. The barriers and suggested approaches to the successful resolution of these problems are described. Chronic psychiatric problems such as depression and psychosis along with personality problems and stress are recognized as posing added challenge and are briefly presented with emphasis on recent advances in their management.

Dualism and its place in a philosophical structure for psychiatry.

PubMed

Maung, Hane Htut

2018-05-19

It is often claimed in parts of the psychiatric literature that neuroscientific research into the biological basis of mental disorder undermines dualism in the philosophy of mind. This paper shows that such a claim does not apply to all forms of dualism. Focusing on Kenneth Kendler's discussion of the mind-body problem in biological psychiatry, I argue that such criticism of dualism often conflates the psychological and phenomenal concepts of the mental. Moreover, it fails to acknowledge that there are different varieties of dualism, and so overlooks the important metaphysical insights of contemporary dualist philosophers. I argue that while the neuroscientific research underpinning biological psychiatry challenges the traditional dualism of René Descartes, it does not pose any problem for the more modern dualism of David Chalmers. It is possible to take seriously the scientific claims of biological psychiatry while holding that this latter form of dualism is true. This has implications for the positioning of the mind-body problem in psychiatry. While the "easy" problem of explaining psychological processes is relevant to the aims of biological psychiatry, psychiatrists need not worry about the "hard" problem of consciousness.

Physics and nuclear power

NASA Astrophysics Data System (ADS)

Buttery, N. E.

2008-03-01

Nuclear power owes its origin to physicists. Fission was demonstrated by physicists and chemists and the first nuclear reactor project was led by physicists. However as nuclear power was harnessed to produce electricity the role of the engineer became stronger. Modern nuclear power reactors bring together the skills of physicists, chemists, chemical engineers, electrical engineers, mechanical engineers and civil engineers. The paper illustrates this by considering the Sizewell B project and the role played by physicists in this. This covers not only the roles in design and analysis but in problem solving during the commissioning of first of a kind plant. Looking forward to the challenges to provide sustainable and environmentally acceptable energy sources for the future illustrates the need for a continuing synergy between physics and engineering. This will be discussed in the context of the challenges posed by Generation IV reactors.

Meanings Given to Algebraic Symbolism in Problem-Posing

ERIC Educational Resources Information Center

Cañadas, María C.; Molina, Marta; del Río, Aurora

2018-01-01

Some errors in the learning of algebra suggest that students might have difficulties giving meaning to algebraic symbolism. In this paper, we use problem posing to analyze the students' capacity to assign meaning to algebraic symbolism and the difficulties that students encounter in this process, depending on the characteristics of the algebraic…

Enhancing Students' Communication Skills through Problem Posing and Presentation

ERIC Educational Resources Information Center

Sugito; E. S., Sri Mulyani; Hartono; Supartono

2017-01-01

This study was to explore how enhance communication skill through problem posing and presentation method. The subjects of this research were the seven grade students Junior High School, including 20 male and 14 female. This research was conducted in two cycles and each cycle consisted of four steps, they were: planning, action, observation, and…

Image-based aircraft pose estimation: a comparison of simulations and real-world data

NASA Astrophysics Data System (ADS)

Breuers, Marcel G. J.; de Reus, Nico

2001-10-01

The problem of estimating aircraft pose information from mono-ocular image data is considered using a Fourier descriptor based algorithm. The dependence of pose estimation accuracy on image resolution and aspect angle is investigated through simulations using sets of synthetic aircraft images. Further evaluation shows that god pose estimation accuracy can be obtained in real world image sequences.

DOCKSCORE: a webserver for ranking protein-protein docked poses.

PubMed

Malhotra, Sony; Mathew, Oommen K; Sowdhamini, Ramanathan

2015-04-24

Proteins interact with a variety of other molecules such as nucleic acids, small molecules and other proteins inside the cell. Structure-determination of protein-protein complexes is challenging due to several reasons such as the large molecular weights of these macromolecular complexes, their dynamic nature, difficulty in purification and sample preparation. Computational docking permits an early understanding of the feasibility and mode of protein-protein interactions. However, docking algorithms propose a number of solutions and it is a challenging task to select the native or near native pose(s) from this pool. DockScore is an objective scoring scheme that can be used to rank protein-protein docked poses. It considers several interface parameters, namely, surface area, evolutionary conservation, hydrophobicity, short contacts and spatial clustering at the interface for scoring. We have implemented DockScore in form of a webserver for its use by the scientific community. DockScore webserver can be employed, subsequent to docking, to perform scoring of the docked solutions, starting from multiple poses as inputs. The results, on scores and ranks for all the poses, can be downloaded as a csv file and graphical view of the interface of best ranking poses is possible. The webserver for DockScore is made freely available for the scientific community at: http://caps.ncbs.res.in/dockscore/ .

Infrared variation reduction by simultaneous background suppression and target contrast enhancement for deep convolutional neural network-based automatic target recognition

NASA Astrophysics Data System (ADS)

Kim, Sungho

2017-06-01

Automatic target recognition (ATR) is a traditionally challenging problem in military applications because of the wide range of infrared (IR) image variations and the limited number of training images. IR variations are caused by various three-dimensional target poses, noncooperative weather conditions (fog and rain), and difficult target acquisition environments. Recently, deep convolutional neural network-based approaches for RGB images (RGB-CNN) showed breakthrough performance in computer vision problems, such as object detection and classification. The direct use of RGB-CNN to the IR ATR problem fails to work because of the IR database problems (limited database size and IR image variations). An IR variation-reduced deep CNN (IVR-CNN) to cope with the problems is presented. The problem of limited IR database size is solved by a commercial thermal simulator (OKTAL-SE). The second problem of IR variations is mitigated by the proposed shifted ramp function-based intensity transformation. This can suppress the background and enhance the target contrast simultaneously. The experimental results on the synthesized IR images generated by the thermal simulator (OKTAL-SE) validated the feasibility of IVR-CNN for military ATR applications.

Harnessing Aptamers to Overcome Challenges in Gluten Detection

PubMed Central

Miranda-Castro, Rebeca; de-los-Santos-Álvarez, Noemí; Miranda-Ordieres, Arturo J.; Lobo-Castañón, María Jesús

2016-01-01

Celiac disease is a lifelong autoimmune disorder triggered by foods containing gluten, the storage protein in wheat, rye, and barley. The rapidly escalating number of patients diagnosed with this disease poses a great challenge to both food industry and authorities to guarantee food safety for all. Therefore, intensive efforts are being made to establish minimal disease-eliciting doses of gluten and consequently to improve gluten-free labeling. These efforts depend to a high degree on the availability of methods capable of detecting the protein in food samples at levels as low as possible. Current analytical approaches rely on the use of antibodies as selective recognition elements. With limited sensitivity, these methods exhibit some deficiencies that compromise the accuracy of the obtained results. Aptamers provide an ideal alternative for designing biosensors for fast and selective measurement of gluten in foods. This article highlights the challenges in gluten detection, the current status of the use of aptamers for solving this problem, and what remains to be done to move these systems into commercial applications. PMID:27104578

Digital Pharmacovigilance and Disease Surveillance: Combining Traditional and Big-Data Systems for Better Public Health.

PubMed

Salathé, Marcel

2016-12-01

The digital revolution has contributed to very large data sets (ie, big data) relevant for public health. The two major data sources are electronic health records from traditional health systems and patient-generated data. As the two data sources have complementary strengths-high veracity in the data from traditional sources and high velocity and variety in patient-generated data-they can be combined to build more-robust public health systems. However, they also have unique challenges. Patient-generated data in particular are often completely unstructured and highly context dependent, posing essentially a machine-learning challenge. Some recent examples from infectious disease surveillance and adverse drug event monitoring demonstrate that the technical challenges can be solved. Despite these advances, the problem of verification remains, and unless traditional and digital epidemiologic approaches are combined, these data sources will be constrained by their intrinsic limits. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America.

Probabilistic Elastic Part Model: A Pose-Invariant Representation for Real-World Face Verification.

PubMed

Li, Haoxiang; Hua, Gang

2018-04-01

Pose variation remains to be a major challenge for real-world face recognition. We approach this problem through a probabilistic elastic part model. We extract local descriptors (e.g., LBP or SIFT) from densely sampled multi-scale image patches. By augmenting each descriptor with its location, a Gaussian mixture model (GMM) is trained to capture the spatial-appearance distribution of the face parts of all face images in the training corpus, namely the probabilistic elastic part (PEP) model. Each mixture component of the GMM is confined to be a spherical Gaussian to balance the influence of the appearance and the location terms, which naturally defines a part. Given one or multiple face images of the same subject, the PEP-model builds its PEP representation by sequentially concatenating descriptors identified by each Gaussian component in a maximum likelihood sense. We further propose a joint Bayesian adaptation algorithm to adapt the universally trained GMM to better model the pose variations between the target pair of faces/face tracks, which consistently improves face verification accuracy. Our experiments show that we achieve state-of-the-art face verification accuracy with the proposed representations on the Labeled Face in the Wild (LFW) dataset, the YouTube video face database, and the CMU MultiPIE dataset.

Rational approximations to rational models: alternative algorithms for category learning.

PubMed

Sanborn, Adam N; Griffiths, Thomas L; Navarro, Daniel J

2010-10-01

Rational models of cognition typically consider the abstract computational problems posed by the environment, assuming that people are capable of optimally solving those problems. This differs from more traditional formal models of cognition, which focus on the psychological processes responsible for behavior. A basic challenge for rational models is thus explaining how optimal solutions can be approximated by psychological processes. We outline a general strategy for answering this question, namely to explore the psychological plausibility of approximation algorithms developed in computer science and statistics. In particular, we argue that Monte Carlo methods provide a source of rational process models that connect optimal solutions to psychological processes. We support this argument through a detailed example, applying this approach to Anderson's (1990, 1991) rational model of categorization (RMC), which involves a particularly challenging computational problem. Drawing on a connection between the RMC and ideas from nonparametric Bayesian statistics, we propose 2 alternative algorithms for approximate inference in this model. The algorithms we consider include Gibbs sampling, a procedure appropriate when all stimuli are presented simultaneously, and particle filters, which sequentially approximate the posterior distribution with a small number of samples that are updated as new data become available. Applying these algorithms to several existing datasets shows that a particle filter with a single particle provides a good description of human inferences.

Viewpoint Invariant Gesture Recognition and 3D Hand Pose Estimation Using RGB-D

ERIC Educational Resources Information Center

Doliotis, Paul

2013-01-01

The broad application domain of the work presented in this thesis is pattern classification with a focus on gesture recognition and 3D hand pose estimation. One of the main contributions of the proposed thesis is a novel method for 3D hand pose estimation using RGB-D. Hand pose estimation is formulated as a database retrieval problem. The proposed…

Multi-view non-negative tensor factorization as relation learning in healthcare data.

PubMed

Hang Wu; Wang, May D

2016-08-01

Discovering patterns in co-occurrences data between objects and groups of concepts is a useful task in many domains, such as healthcare data analysis, information retrieval, and recommender systems. These relational representations come from objects' behaviors in different views, posing a challenging task of integrating information from these views to uncover the shared latent structures. The problem is further complicated by the high dimension of data and the large ratio of missing data. We propose a new paradigm of learning semantic relations using tensor factorization, by jointly factorizing multi-view tensors and searching for a consistent underlying semantic space across each views. We formulate the idea as an optimization problem and propose efficient optimization algorithms, with a special treatment of missing data as well as high-dimensional data. Experiments results show the potential and effectiveness of our algorithms.

Energy stable and high-order-accurate finite difference methods on staggered grids

NASA Astrophysics Data System (ADS)

O'Reilly, Ossian; Lundquist, Tomas; Dunham, Eric M.; Nordström, Jan

2017-10-01

For wave propagation over distances of many wavelengths, high-order finite difference methods on staggered grids are widely used due to their excellent dispersion properties. However, the enforcement of boundary conditions in a stable manner and treatment of interface problems with discontinuous coefficients usually pose many challenges. In this work, we construct a provably stable and high-order-accurate finite difference method on staggered grids that can be applied to a broad class of boundary and interface problems. The staggered grid difference operators are in summation-by-parts form and when combined with a weak enforcement of the boundary conditions, lead to an energy stable method on multiblock grids. The general applicability of the method is demonstrated by simulating an explosive acoustic source, generating waves reflecting against a free surface and material discontinuity.

Hybrid Quantum-Classical Approach to Quantum Optimal Control.

PubMed

Li, Jun; Yang, Xiaodong; Peng, Xinhua; Sun, Chang-Pu

2017-04-14

A central challenge in quantum computing is to identify more computational problems for which utilization of quantum resources can offer significant speedup. Here, we propose a hybrid quantum-classical scheme to tackle the quantum optimal control problem. We show that the most computationally demanding part of gradient-based algorithms, namely, computing the fitness function and its gradient for a control input, can be accomplished by the process of evolution and measurement on a quantum simulator. By posing queries to and receiving answers from the quantum simulator, classical computing devices update the control parameters until an optimal control solution is found. To demonstrate the quantum-classical scheme in experiment, we use a seven-qubit nuclear magnetic resonance system, on which we have succeeded in optimizing state preparation without involving classical computation of the large Hilbert space evolution.

Gravity-Off-loading System for Large-Displacement Ground Testing of Spacecraft Mechanisms

NASA Technical Reports Server (NTRS)

Han, Olyvia; Kienholz, David; Janzen, Paul; Kidney, Scott

2010-01-01

Gravity-off-loading of deployable spacecraft mechanisms during ground testing is a long-standing problem. Deployable structures which are usually too weak to support their own weight under gravity require a means of gravity-off-loading as they unfurl. Conventional solutions to this problem have been helium-filled balloons or mechanical pulley/counterweight systems. These approaches, however, suffer from the deleterious effects of added inertia or friction forces. The changing form factor of the deployable structure itself and the need to track the trajectory of the center of gravity also pose a challenge to these conventional technologies. This paper presents a novel testing apparatus for high-fidelity zero-gravity simulation for special application to deployable space structures such as solar arrays, magnetometer booms, and robotic arms in class 100,000 clean room environments

On inflating magnetic fields, and the backreactions thereof

DOE Office of Scientific and Technical Information (OSTI.GOV)

Urban, Federico R., E-mail: urban@phas.ubc.ca

2011-12-01

We investigate in more depth the issue of backreaction in models that attempt at generating cosmological magnetic fields at inflation. By choosing different, physically motivated, parametrisations, we are able to isolate the heart of the problem, namely the existence, alongside the wanted magnetic field, of its electric counterpart, which turns out quite generally to be stronger and redder. We were also able to identify a few more interwoven weak spots (the typically very high scale of inflation, the width of the spectrum of modes processed by inflation, the blindness of the amplification mechanism to the energy scale processed), in amore » way independent on the specifications of the coupling between inflation and electromagnetism. Despite having stripped down the problem to the core, the obstacles encountered appear insurmountable, thereby posing a challenge to inflation as the incubator of cosmological magnetism.« less

Covariance Matrix Estimation for the Cryo-EM Heterogeneity Problem*

PubMed Central

Katsevich, E.; Katsevich, A.; Singer, A.

2015-01-01

In cryo-electron microscopy (cryo-EM), a microscope generates a top view of a sample of randomly oriented copies of a molecule. The problem of single particle reconstruction (SPR) from cryo-EM is to use the resulting set of noisy two-dimensional projection images taken at unknown directions to reconstruct the three-dimensional (3D) structure of the molecule. In some situations, the molecule under examination exhibits structural variability, which poses a fundamental challenge in SPR. The heterogeneity problem is the task of mapping the space of conformational states of a molecule. It has been previously suggested that the leading eigenvectors of the covariance matrix of the 3D molecules can be used to solve the heterogeneity problem. Estimating the covariance matrix is challenging, since only projections of the molecules are observed, but not the molecules themselves. In this paper, we formulate a general problem of covariance estimation from noisy projections of samples. This problem has intimate connections with matrix completion problems and high-dimensional principal component analysis. We propose an estimator and prove its consistency. When there are finitely many heterogeneity classes, the spectrum of the estimated covariance matrix reveals the number of classes. The estimator can be found as the solution to a certain linear system. In the cryo-EM case, the linear operator to be inverted, which we term the projection covariance transform, is an important object in covariance estimation for tomographic problems involving structural variation. Inverting it involves applying a filter akin to the ramp filter in tomography. We design a basis in which this linear operator is sparse and thus can be tractably inverted despite its large size. We demonstrate via numerical experiments on synthetic datasets the robustness of our algorithm to high levels of noise. PMID:25699132

Development of a Mobile Learning System Based on a Collaborative Problem-Posing Strategy

ERIC Educational Resources Information Center

Sung, Han-Yu; Hwang, Gwo-Jen; Chang, Ya-Chi

2016-01-01

In this study, a problem-posing strategy is proposed for supporting collaborative mobile learning activities. Accordingly, a mobile learning environment has been developed, and an experiment on a local culture course has been conducted to evaluate the effectiveness of the proposed approach. Three classes of an elementary school in southern Taiwan…

An Investigation of Pattern Problems Posed by Middle School Mathematics Preservice Teachers Using Multiple Representation

ERIC Educational Resources Information Center

Yilmaz, Yasemin; Durmus, Soner; Yaman, Hakan

2018-01-01

This study investigated the pattern problems posed by middle school mathematics preservice teachers using multiple representations to determine both their pattern knowledge levels and their abilities to transfer this knowledge to students. The design of the study is the survey method, one of the quantitative research methods. The study group was…

Problem-Posing as a Didactic Resource in Formal Mathematics Courses to Train Future Secondary School Mathematics Teachers

ERIC Educational Resources Information Center

Solórzano, Lorena Salazar

2015-01-01

Beginning university training programs must focus on different competencies for mathematics teachers, i.e., not only on solving problems, but also on posing them and analyzing the mathematical activity. This paper reports the results of an exploratory study conducted with future secondary school mathematics teachers on the introduction of…

Committee-Based Active Learning for Surrogate-Assisted Particle Swarm Optimization of Expensive Problems.

PubMed

Wang, Handing; Jin, Yaochu; Doherty, John

2017-09-01

Function evaluations (FEs) of many real-world optimization problems are time or resource consuming, posing a serious challenge to the application of evolutionary algorithms (EAs) to solve these problems. To address this challenge, the research on surrogate-assisted EAs has attracted increasing attention from both academia and industry over the past decades. However, most existing surrogate-assisted EAs (SAEAs) either still require thousands of expensive FEs to obtain acceptable solutions, or are only applied to very low-dimensional problems. In this paper, a novel surrogate-assisted particle swarm optimization (PSO) inspired from committee-based active learning (CAL) is proposed. In the proposed algorithm, a global model management strategy inspired from CAL is developed, which searches for the best and most uncertain solutions according to a surrogate ensemble using a PSO algorithm and evaluates these solutions using the expensive objective function. In addition, a local surrogate model is built around the best solution obtained so far. Then, a PSO algorithm searches on the local surrogate to find its optimum and evaluates it. The evolutionary search using the global model management strategy switches to the local search once no further improvement can be observed, and vice versa. This iterative search process continues until the computational budget is exhausted. Experimental results comparing the proposed algorithm with a few state-of-the-art SAEAs on both benchmark problems up to 30 decision variables as well as an airfoil design problem demonstrate that the proposed algorithm is able to achieve better or competitive solutions with a limited budget of hundreds of exact FEs.

The challenge posed to children's health by mixtures of toxic waste: the Tar Creek superfund site as a case-study.

PubMed

Hu, Howard; Shine, James; Wright, Robert O

2007-02-01

In the United States, many of the millions of tons of hazardous wastes that have been produced since World War II have accumulated in sites throughout the nation. Citizen concern about the extent of this problem led Congress to establish the Superfund Program in 1980 to locate, investigate, and clean up the worst sites nationwide. Most such waste exists as a complex mixture of many substances. This article discusses the issue of toxic mixtures and children's health by focusing on the specific example of mining waste at the Tar Creek Superfund Site in Northeast Oklahoma.

Transcutaneous closure of chronic broncho-pleuro-cutaneous fistula by duct occluder device

PubMed Central

Marwah, Vikas; Ravikumar, R; Rajput, Ashok Kumar; Singh, Amandeep

2016-01-01

Bronchopleural fistula (BPF) is a well known complication of several pulmonary conditions posing challenging management problem and is often associated with high morbidity and mortality. Though no consensus exists on a definite closure management algorithm, strategies for closure widely include various methods like tube thoracostomy with suction, open surgical closure, bronchoscopy directed glue, coiling and sealants which now also includes use of occlusion devices. We report a case in which a novel method of delivery and closure of recurrent post-operative broncho-pleuro-cutaneous fistula by a duct occluder device was done transcutaneously which has not been previously described in literature. PMID:27051115

A clinical guide to needle desensitization for the paediatric patient.

PubMed

Taylor, Greig D; Campbell, Caroline

2015-05-01

Needle phobia is a common problem encountered by dental practitioners and it can pose a challenge, especially in the paediatric patient. Needle desensitization can be used for patients who have needle fear or phobia and help them overcome this by repeated, non-threatening and controlled contacts. This paper will describe an accepted technique of needle desensitization and work through the steps required to achieve a successful outcome of local anaesthesia being delivered in a calm, safe and controlled manner. Clinical Relevance: Needle desensitization is an effective technique which can be used to enable a needle phobic patient to receive a dental injection.

Diet, exercise, behavior: the promise and limits of lifestyle change.

PubMed

Bennett, Brian; Sothern, Melinda S

2009-08-01

The prevalent surge in childhood and adolescent obesity within the past 3 decades poses a significant challenge for many pediatric clinicians who are charged with treating this condition. Comprehensive, research-based pediatric obesity treatment programs are essential to addressing this problem and preventing the transition of obesity and its many comorbidities into adulthood. This paper will identify dietary, physical activity, and behavioral approaches to lifestyle change and describe how they are incorporated as part of multidisciplinary treatment interventions in youth. Specific tailoring of treatment programs to address age and varying degrees of overweight and obesity will also be presented along with recommendations for future research.

NetWall distributed firewall in the use of campus network

NASA Astrophysics Data System (ADS)

He, Junhua; Zhang, Pengshuai

2011-10-01

Internet provides a modern means of education but also non-mainstream consciousness and poor dissemination of information opens the door, network and moral issues have become prominent, poor dissemination of information and network spread rumors and negative effects of new problems, ideological and political education in schools had a huge impact, poses a severe challenge. This paper presents a distributed firewall will NetWall deployed in a campus network solution. The characteristics of the campus network, using technology to filter out bad information on the means of control, of sensitive information related to the record, establish a complete information security management platform for the campus network.

Prophylactic Therapy for Hereditary Angioedema.

PubMed

Longhurst, Hilary; Zinser, Emily

2017-08-01

Long-term prophylaxis is needed in many patients with hereditary angioedema and poses many challenges. Attenuated androgens are effective in many but are limited by side effect profiles. There is less evidence for efficacy of tranexamic acid and progestagens; however, the small side effect profile makes tranexamic acid an option for prophylaxis in children and progestagens an option for women. C1 inhibitor is beneficial, but at present requires intravenous delivery and may need dose titration for maximum efficacy. Short-term prophylaxis should be considered for all procedures. New therapies are promising in overcoming many problems encountered with current options for long-term prophylaxis. Copyright © 2017 Elsevier Inc. All rights reserved.

Advances in risk assessment and communication.

PubMed

Goldstein, Bernard D

2005-01-01

Risk analysis continues to evolve. There is increasing depth and breadth to each component of the four-step risk-assessment paradigm of hazard identification, dose-response analysis, exposure assessment, and risk characterization. Basic conceptual approaches to understanding how people perceive risk are being tested against a growing body of empirical observations, many involving stakeholders. Emerging ideas such as the precautionary principle have provided challenges that have led to a rethinking of the role of risk assessment in environmental health. Newer problems, such as intergenerational issues posed by long-lasting radiation pollution, environmental justice, and the assessment and communication of risks related to terrorism, have spurred innovative approaches to risk analysis.

Bench-to-bedside review: The MET syndrome – the challenges of researching and adopting medical emergency teams

PubMed Central

Tee, Augustine; Calzavacca, Paolo; Licari, Elisa; Goldsmith, Donna; Bellomo, Rinaldo

2008-01-01

Studies of hospital performance highlight the problem of 'failure to rescue' in acutely ill patients. This is a deficiency strongly associated with serious adverse events, cardiac arrest, or death. Rapid response systems (RRSs) and their efferent arm, the medical emergency team (MET), provide early specialist critical care to patients affected by the 'MET syndrome': unequivocal physiological instability or significant hospital staff concern for patients in a non-critical care environment. This intervention aims to prevent serious adverse events, cardiac arrests, and unexpected deaths. Though clinically logical and relatively simple, its adoption poses major challenges. Furthermore, research about the effectiveness of RRS is difficult to conduct. Sceptics argue that inadequate evidence exists to support its widespread application. Indeed, supportive evidence is based on before-and-after studies, observational investigations, and inductive reasoning. However, implementing a complex intervention like RRS poses enormous logistic, political, cultural, and financial challenges. In addition, double-blinded randomised controlled trials of RRS are simply not possible. Instead, as in the case of cardiac arrest and trauma teams, change in practice may be slow and progressive, even in the absence of level I evidence. It appears likely that the accumulation of evidence from different settings and situations, though methodologically imperfect, will increase the rationale and logic of RRS. A conclusive randomised controlled trial is unlikely to occur. All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident. Arthur Schopenhauer (1788–1860), German philosopher PMID:18254927

Challenges created by data dissemination and access restrictions when attempting to address community concerns: individual privacy versus public wellbeing.

PubMed

Colquhoun, Amy; Aplin, Laura; Geary, Janis; Goodman, Karen J; Hatcher, Juanita

2012-05-08

Population health data are vital for the identification of public health problems and the development of public health strategies. Challenges arise when attempts are made to disseminate or access anonymised data that are deemed to be potentially identifiable. In these situations, there is debate about whether the protection of an individual's privacy outweighs potentially beneficial public health initiatives developed using potentially identifiable information. While these issues have an impact at planning and policy levels, they pose a particular dilemma when attempting to examine and address community concerns about a specific health problem. Research currently underway in northern Canadian communities on the frequency of Helicobacter pylori infection and associated diseases, such as stomach cancer, is used in this article to illustrate the challenges that data controls create on the ability of researchers and health officials to address community concerns. Barriers are faced by public health professionals and researchers when endeavouring to address community concerns; specifically, provincial cancer surveillance departments and community-driven participatory research groups face challenges related to data release or access that inhibit their ability to effectively address community enquiries. The resulting consequences include a limited ability to address misinformation or to alleviate concerns when dealing with health problems in small communities. The development of communication tools and building of trusting relationships are essential components of a successful investigation into community health concerns. It may also be important to consider that public wellbeing may outweigh the value of individual privacy in these situations. As such, a re-evaluation of data disclosure policies that are applicable in these circumstances should be considered.

The inverse problems of wing panel manufacture processes

NASA Astrophysics Data System (ADS)

Oleinikov, A. I.; Bormotin, K. S.

2013-12-01

It is shown that inverse problems of steady-state creep bending of plates in both the geometrically linear and nonlinear formulations can be represented in a variational formulation. Steady-state values of the obtained functionals corresponding to the solutions of the problems of inelastic deformation and springback are determined by applying a finite element procedure to the functionals. Optimal laws of creep deformation are formulated using the criterion of minimizing damage in the functionals of the inverse problems. The formulated problems are reduced to the problems solved by the finite element method using MSC.Marc software. Currently, forming of light metals poses tremendous challenges due to their low ductility at room temperature and their unusual deformation characteristics at hot-cold work: strong asymmetry between tensile and compressive behavior, and a very pronounced anisotropy. We used the constitutive models of steady-state creep of initially transverse isotropy structural materials the kind of the stress state has influence. The paper gives basics of the developed computer-aided system of design, modeling, and electronic simulation targeting the processes of manufacture of wing integral panels. The modeling results can be used to calculate the die tooling, determine the panel processibility, and control panel rejection in the course of forming.

Assimilating data into open ocean tidal models

NASA Astrophysics Data System (ADS)

Kivman, Gennady A.

The problem of deriving tidal fields from observations by reason of incompleteness and imperfectness of every data set practically available has an infinitely large number of allowable solutions fitting the data within measurement errors and hence can be treated as ill-posed. Therefore, interpolating the data always relies on some a priori assumptions concerning the tides, which provide a rule of sampling or, in other words, a regularization of the ill-posed problem. Data assimilation procedures used in large scale tide modeling are viewed in a common mathematical framework as such regularizations. It is shown that they all (basis functions expansion, parameter estimation, nudging, objective analysis, general inversion, and extended general inversion), including those (objective analysis and general inversion) originally formulated in stochastic terms, may be considered as utilizations of one of the three general methods suggested by the theory of ill-posed problems. The problem of grid refinement critical for inverse methods and nudging is discussed.

The Challenges of Career and Technical Education Concurrent Enrollment: An Administrative Perspective

ERIC Educational Resources Information Center

Haag, Patricia W.

2015-01-01

Career and technical education concurrent enrollment may pose unique challenges in programming and enrollment for program administrators, and this chapter describes the experiences and challenges of a CTE concurrent enrollment administrator.

Easier said than done: challenges of applying the Ecohealth approach to the study on heavy metals exposure among indigenous communities of the Peruvian Amazon.

PubMed

Anticona, Cynthia; Coe, Anna-Britt; Bergdahl, Ingvar A; San Sebastian, Miguel

2013-05-03

The renewed interest in community participation in health research is linked to its potential for bridging gaps between research and practice. Its main attributes are the generation of knowledge that can lead to socially robust, long-lasting solutions and the creation of a co-learner relationship between researchers and research users. Following this philosophy, Ecohealth has evolved into a specialized framework for participatory research on the impact of pollution on ecosystems and human health. However, its principles pose considerable challenges. Its outcomes are strongly influenced by contextual factors that are impossible to control for ahead of time.This paper describes how the Ecohealth principles were applied to an epidemiological study of heavy metals exposure among indigenous communities of the Peruvian Amazon. It illustrates how knowledge generated from participatory research does not necessarily imply solving a public health problem. This study aimed to contribute to the understanding of the benefits and barriers of following the basic principles of the Ecohealth approach, and assist researchers working in similar contexts. Based upon their personal experience as participant observers, the authors describe the research process; then, they discuss the most important challenges faced, their implications, and the attempted strategies for resolution. Challenges were grouped into four themes: (1) building trust; (2) one partnership, many stakeholders, multiple agendas; (3) being a researcher; and (4) communicating complex and unexpected findings. Integrating the principles of transdisciplinarity and participation posed a series of challenges to the research process that were difficult, and sometimes impossible to overcome. However, positive outcomes from this experience were the lessons learned by the different actors. Despite the lack of immediate action, it is expected that useful interventions to prevent and control lead exposure in the Corrientes population will be implemented in the medium term.

Solution to the SLAM problem in low dynamic environments using a pose graph and an RGB-D sensor.

PubMed

Lee, Donghwa; Myung, Hyun

2014-07-11

In this study, we propose a solution to the simultaneous localization and mapping (SLAM) problem in low dynamic environments by using a pose graph and an RGB-D (red-green-blue depth) sensor. The low dynamic environments refer to situations in which the positions of objects change over long intervals. Therefore, in the low dynamic environments, robots have difficulty recognizing the repositioning of objects unlike in highly dynamic environments in which relatively fast-moving objects can be detected using a variety of moving object detection algorithms. The changes in the environments then cause groups of false loop closing when the same moved objects are observed for a while, which means that conventional SLAM algorithms produce incorrect results. To address this problem, we propose a novel SLAM method that handles low dynamic environments. The proposed method uses a pose graph structure and an RGB-D sensor. First, to prune the falsely grouped constraints efficiently, nodes of the graph, that represent robot poses, are grouped according to the grouping rules with noise covariances. Next, false constraints of the pose graph are pruned according to an error metric based on the grouped nodes. The pose graph structure is reoptimized after eliminating the false information, and the corrected localization and mapping results are obtained. The performance of the method was validated in real experiments using a mobile robot system.

Scheduling Future Water Supply Investments Under Uncertainty

NASA Astrophysics Data System (ADS)

Huskova, I.; Matrosov, E. S.; Harou, J. J.; Kasprzyk, J. R.; Reed, P. M.

2014-12-01

Uncertain hydrological impacts of climate change, population growth and institutional changes pose a major challenge to planning of water supply systems. Planners seek optimal portfolios of supply and demand management schemes but also when to activate assets whilst considering many system goals and plausible futures. Incorporation of scheduling into the planning under uncertainty problem strongly increases its complexity. We investigate some approaches to scheduling with many-objective heuristic search. We apply a multi-scenario many-objective scheduling approach to the Thames River basin water supply system planning problem in the UK. Decisions include which new supply and demand schemes to implement, at what capacity and when. The impact of different system uncertainties on scheme implementation schedules are explored, i.e. how the choice of future scenarios affects the search process and its outcomes. The activation of schemes is influenced by the occurrence of extreme hydrological events in the ensemble of plausible scenarios and other factors. The approach and results are compared with a previous study where only the portfolio problem is addressed (without scheduling).

Using Inverse Problem Methods with Surveillance Data in Pneumococcal Vaccination

PubMed Central

Sutton, Karyn L.; Banks, H. T.; Castillo-Chavez, Carlos

2010-01-01

The design and evaluation of epidemiological control strategies is central to public health policy. While inverse problem methods are routinely used in many applications, this remains an area in which their use is relatively rare, although their potential impact is great. We describe methods particularly relevant to epidemiological modeling at the population level. These methods are then applied to the study of pneumococcal vaccination strategies as a relevant example which poses many challenges common to other infectious diseases. We demonstrate that relevant yet typically unknown parameters may be estimated, and show that a calibrated model may used to assess implemented vaccine policies through the estimation of parameters if vaccine history is recorded along with infection and colonization information. Finally, we show how one might determine an appropriate level of refinement or aggregation in the age-structured model given age-stratified observations. These results illustrate ways in which the collection and analysis of surveillance data can be improved using inverse problem methods. PMID:20209093

Decoupled Method for Reconstruction of Surface Conditions From Internal Temperatures On Ablative Materials With Uncertain Recession Model

NASA Technical Reports Server (NTRS)

Oliver, A. Brandon

2017-01-01

Obtaining measurements of flight environments on ablative heat shields is both critical for spacecraft development and extremely challenging due to the harsh heating environment and surface recession. Thermocouples installed several millimeters below the surface are commonly used to measure the heat shield temperature response, but an ill-posed inverse heat conduction problem must be solved to reconstruct the surface heating environment from these measurements. Ablation can contribute substantially to the measurement response making solutions to the inverse problem strongly dependent on the recession model, which is often poorly characterized. To enable efficient surface reconstruction for recession model sensitivity analysis, a method for decoupling the surface recession evaluation from the inverse heat conduction problem is presented. The decoupled method is shown to provide reconstructions of equivalent accuracy to the traditional coupled method but with substantially reduced computational effort. These methods are applied to reconstruct the environments on the Mars Science Laboratory heat shield using diffusion limit and kinetically limited recession models.

Improved pose and affinity predictions using different protocols tailored on the basis of data availability

NASA Astrophysics Data System (ADS)

Prathipati, Philip; Nagao, Chioko; Ahmad, Shandar; Mizuguchi, Kenji

2016-09-01

The D3R 2015 grand drug design challenge provided a set of blinded challenges for evaluating the applicability of our protocols for pose and affinity prediction. In the present study, we report the application of two different strategies for the two D3R protein targets HSP90 and MAP4K4. HSP90 is a well-studied target system with numerous co-crystal structures and SAR data. Furthermore the D3R HSP90 test compounds showed high structural similarity to existing HSP90 inhibitors in BindingDB. Thus, we adopted an integrated docking and scoring approach involving a combination of both pharmacophoric and heavy atom similarity alignments, local minimization and quantitative structure activity relationships modeling, resulting in the reasonable prediction of pose [with the root mean square deviation (RMSD) values of 1.75 Å for mean pose 1, 1.417 Å for the mean best pose and 1.85 Å for the mean all poses] and affinity (ROC AUC = 0.702 at 7.5 pIC50 cut-off and R = 0.45 for 180 compounds). The second protein, MAP4K4, represents a novel system with limited SAR and co-crystal structure data and little structural similarity of the D3R MAP4K4 test compounds to known MAP4K4 ligands. For this system, we implemented an exhaustive pose and affinity prediction protocol involving docking and scoring using the PLANTS software which considers side chain flexibility together with protein-ligand fingerprints analysis assisting in pose prioritization. This protocol through fares poorly in pose prediction (with the RMSD values of 4.346 Å for mean pose 1, 4.69 Å for mean best pose and 4.75 Å for mean all poses) and produced reasonable affinity prediction (AUC = 0.728 at 7.5 pIC50 cut-off and R = 0.67 for 18 compounds, ranked 1st among 80 submissions).

Engaging in Problem Posing Activities in a Dynamic Geometry Setting and the Development of Prospective Teachers' Mathematical Knowledge

ERIC Educational Resources Information Center

Lavy, Ilana; Shriki, Atara

2010-01-01

In the present study we explore changes in perceptions of our class of prospective mathematics teachers (PTs) regarding their mathematical knowledge. The PTs engaged in problem posing activities in geometry, using the "What If Not?" (WIN) strategy, as part of their work on computerized inquiry-based activities. Data received from the PTs'…

Mathematical Problem Posing as a Measure of Curricular Effect on Students' Learning

ERIC Educational Resources Information Center

Cai, Jinfa; Moyer, John C.; Wang, Ning; Hwang, Stephen; Nie, Bikai; Garber, Tammy

2013-01-01

In this study, we used problem posing as a measure of the effect of middle-school curriculum on students' learning in high school. Students who had used a standards-based curriculum in middle school performed equally well or better in high school than students who had used more traditional curricula. The findings from this study not only show…

Global hunger: a challenge to agricultural, food, and nutritional sciences.

PubMed

Wu, Shiuan-Huei; Ho, Chi-Tang; Nah, Sui-Lin; Chau, Chi-Fai

2014-01-01

Hunger has been a concern for generations and has continued to plague hundreds of millions of people around the world. Although many efforts have been devoted to reduce hunger, challenges such as growing competitions for natural resources, emerging climate changes and natural disasters, poverty, illiteracy, and diseases are posing threats to food security and intensifying the hunger crisis. Concerted efforts of scientists to improve agricultural and food productivity, technology, nutrition, and education are imperative to facilitate appropriate strategies for defeating hunger and malnutrition. This paper provides some aspects of world hunger issues and summarizes the efforts and measures aimed to alleviate food problems from the food and nutritional sciences perspectives. The prospects and constraints of some implemented strategies for alleviating hunger and achieving sustainable food security are also discussed. This comprehensive information source could provide insights into the development of a complementary framework for dealing with the global hunger issue.

The Diabetic foot: A global threat and a huge challenge for Greece

PubMed Central

Papanas, N; Maltezos, E

2009-01-01

The diabetic foot continues to be a major cause of morbidity, posing a global threat. Substantial progress has been now accomplished in the treatment of foot lesions, but further improvement is required. Treatment options may be classified into established measures (revascularisation, casting and debridement) and new modalities. All therapeutic measures should be provided by specialised dedicated multidisciplinary foot clinics. In particular, the diabetic foot is a huge challenge for Greece. There is a dramatic need to increase the number of engaged foot care teams and their resources throughout the country. It is also desirable to continue education of both physicians and general diabetic population on the magnitude of the problem and on the suitable preventative measures. At the same time, more data on the prevalence and clinical manifestations of the diabetic foot in Greece should be carefully collected. Finally, additional research should investigate feasible ways of implementing current knowledge in everyday clinical practice. PMID:20011082

A component-based software environment for visualizing large macromolecular assemblies.

PubMed

Sanner, Michel F

2005-03-01

The interactive visualization of large biological assemblies poses a number of challenging problems, including the development of multiresolution representations and new interaction methods for navigating and analyzing these complex systems. An additional challenge is the development of flexible software environments that will facilitate the integration and interoperation of computational models and techniques from a wide variety of scientific disciplines. In this paper, we present a component-based software development strategy centered on the high-level, object-oriented, interpretive programming language: Python. We present several software components, discuss their integration, and describe some of their features that are relevant to the visualization of large molecular assemblies. Several examples are given to illustrate the interoperation of these software components and the integration of structural data from a variety of experimental sources. These examples illustrate how combining visual programming with component-based software development facilitates the rapid prototyping of novel visualization tools.

New psychoactive substances: catalysing a shift in forensic science practice?

PubMed

Tettey, Justice; Crean, Conor

2015-08-05

The analysis of substances of abuse remains one of the most matured areas in forensic science with a strong scientific basis, namely analytical chemistry. The current evolving drug markets, characterized by the global emergence of new psychoactive substances (NPS) and the need for forensic scientists to identify an unprecedented and ever-increasing number of NPS, presents a unique challenge to this discipline. This article looks at the current situation with NPS at the global level, and the challenges posed to the otherwise technically robust forensic science discipline of analysis of substances of abuse. It discusses the preparedness of forensic science to deal with the current situation and identifies the need for a shift in forensic science practice, especially one which embraces research and looks beyond normal casework in order to provide the much needed data for developing effective policy responses to the NPS problem. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Emerging Infections Program Efforts to Address Health Equity

PubMed Central

Vugia, Duc J.; Bennett, Nancy M.; Moore, Matthew R.

2015-01-01

The Emerging Infections Program (EIP), a collaboration between (currently) 10 state health departments, their academic center partners, and the Centers for Disease Control and Prevention, was established in 1995. The EIP performs active, population-based surveillance for important infectious diseases, addresses new problems as they arise, emphasizes projects that lead to prevention, and develops and evaluates public health practices. The EIP has increasingly addressed the health equity challenges posed by Healthy People 2020. These challenges include objectives to increase the proportion of Healthy People–specified conditions for which national data are available by race/ethnicity and socioeconomic status as a step toward first recognizing and subsequently eliminating health inequities. EIP has made substantial progress in moving from an initial focus on monitoring social determinants exclusively through collecting and analyzing data by race/ethnicity to identifying and piloting ways to conduct population-based surveillance by using area-based socioeconomic status measures. PMID:26291875

The anchoring bias reflects rational use of cognitive resources.

PubMed

Lieder, Falk; Griffiths, Thomas L; M Huys, Quentin J; Goodman, Noah D

2018-02-01

Cognitive biases, such as the anchoring bias, pose a serious challenge to rational accounts of human cognition. We investigate whether rational theories can meet this challenge by taking into account the mind's bounded cognitive resources. We asked what reasoning under uncertainty would look like if people made rational use of their finite time and limited cognitive resources. To answer this question, we applied a mathematical theory of bounded rationality to the problem of numerical estimation. Our analysis led to a rational process model that can be interpreted in terms of anchoring-and-adjustment. This model provided a unifying explanation for ten anchoring phenomena including the differential effect of accuracy motivation on the bias towards provided versus self-generated anchors. Our results illustrate the potential of resource-rational analysis to provide formal theories that can unify a wide range of empirical results and reconcile the impressive capacities of the human mind with its apparently irrational cognitive biases.

An abridged photographic history of organ transplantation.

PubMed

Marino, Ignazio R; Cirillo, Claudia

2014-03-01

Organ transplantation is one of the most remarkable therapeutic advances in modern medicine; it started as an experiment and has become a life-saving practice. We briefly describe the major milestones of this multidisciplinary clinical science, the challenges that it still faces, and we consider the crucial contribution that its example could set for other medical fields. A review of the literature was conducted and a selection of images was made to complete a brief history of organ transplantation, with a particular focus on liver transplantation. The largest problem affecting organ transplantation today is the shortage of organs. Attention should be given to preserving the peculiar high ethical value that characterizes the very nature of organ transplantation. Methods successfully adopted by organ transplantation during the past 60 years can inspire promising fields, such as stem cell research, and provide useful tools to face the ethical challenges posed by scientific discoveries.

Trojan Horse Antibiotics—A Novel Way to Circumvent Gram-Negative Bacterial Resistance?

PubMed Central

Tillotson, Glenn S.

2016-01-01

Antibiotic resistance has been emerged as a major global health problem. In particular, gram-negative species pose a significant clinical challenge as bacteria develop or acquire more resistance mechanisms. Often, these bacteria possess multiple resistance mechanisms, thus nullifying most of the major classes of drugs. Novel approaches to this issue are urgently required. However, the challenges of developing new agents are immense. Introducing novel agents is fraught with hurdles, thus adapting known antibiotic classes by altering their chemical structure could be a way forward. A chemical addition to existing antibiotics known as a siderophore could be a solution to the gram-negative resistance issue. Siderophore molecules rely on the bacterial innate need for iron ions and thus can utilize a Trojan Horse approach to gain access to the bacterial cell. The current approaches to using this potential method are reviewed. PMID:27773991

Reuse of clinical data.

PubMed

Safran, C

2014-08-15

To provide an overview of the benefits of clinical data collected as a by-product of the care process, the potential problems with large aggregations of these data, the policy frameworks that have been formulated, and the major challenges in the coming years. This report summarizes some of the major observations from AMIA and IMIA conferences held on this admittedly broad topic from 2006 through 2013. This report also includes many unsupported opinions of the author. The benefits of aggregating larger and larger sets of routinely collected clinical data are well documented and of great societal benefit. These large data sets will probably never answer all possible clinical questions for methodological reasons. Non-traditional sources of health data that are patient-sources will pose new data science challenges. If we ever hope to have tools that can rapidly provide evidence for daily practice of medicine we need a science of health data perhaps modeled after the science of astronomy.

Trojan Horse Antibiotics-A Novel Way to Circumvent Gram-Negative Bacterial Resistance?

PubMed

Tillotson, Glenn S

2016-01-01

Antibiotic resistance has been emerged as a major global health problem. In particular, gram-negative species pose a significant clinical challenge as bacteria develop or acquire more resistance mechanisms. Often, these bacteria possess multiple resistance mechanisms, thus nullifying most of the major classes of drugs. Novel approaches to this issue are urgently required. However, the challenges of developing new agents are immense. Introducing novel agents is fraught with hurdles, thus adapting known antibiotic classes by altering their chemical structure could be a way forward. A chemical addition to existing antibiotics known as a siderophore could be a solution to the gram-negative resistance issue. Siderophore molecules rely on the bacterial innate need for iron ions and thus can utilize a Trojan Horse approach to gain access to the bacterial cell. The current approaches to using this potential method are reviewed.

Fast reconstruction of optical properties for complex segmentations in near infrared imaging

NASA Astrophysics Data System (ADS)

Jiang, Jingjing; Wolf, Martin; Sánchez Majos, Salvador

2017-04-01

The intrinsic ill-posed nature of the inverse problem in near infrared imaging makes the reconstruction of fine details of objects deeply embedded in turbid media challenging even for the large amounts of data provided by time-resolved cameras. In addition, most reconstruction algorithms for this type of measurements are only suitable for highly symmetric geometries and rely on a linear approximation to the diffusion equation since a numerical solution of the fully non-linear problem is computationally too expensive. In this paper, we will show that a problem of practical interest can be successfully addressed making efficient use of the totality of the information supplied by time-resolved cameras. We set aside the goal of achieving high spatial resolution for deep structures and focus on the reconstruction of complex arrangements of large regions. We show numerical results based on a combined approach of wavelength-normalized data and prior geometrical information, defining a fully parallelizable problem in arbitrary geometries for time-resolved measurements. Fast reconstructions are obtained using a diffusion approximation and Monte-Carlo simulations, parallelized in a multicore computer and a GPU respectively.

Group Work Tests for Context-Rich Problems

NASA Astrophysics Data System (ADS)

Meyer, Chris

2016-05-01

The group work test is an assessment strategy that promotes higher-order thinking skills for solving context-rich problems. With this format, teachers are able to pose challenging, nuanced questions on a test, while providing the support weaker students need to get started and show their understanding. The test begins with a group discussion phase, when students are given a "number-free" version of the problem. This phase allows students to digest the story-like problem, explore solution ideas, and alleviate some test anxiety. After 10-15 minutes of discussion, students inform the instructor of their readiness for the individual part of the test. What follows next is a pedagogical phase change from lively group discussion to quiet individual work. The group work test is a natural continuation of the group work in our daily physics classes and helps reinforce the importance of collaboration. This method has met with success at York Mills Collegiate Institute, in Toronto, Ontario, where it has been used consistently for unit tests and the final exam of the grade 12 university preparation physics course.

Ensemble-based data assimilation and optimal sensor placement for scalar source reconstruction

NASA Astrophysics Data System (ADS)

Mons, Vincent; Wang, Qi; Zaki, Tamer

2017-11-01

Reconstructing the characteristics of a scalar source from limited remote measurements in a turbulent flow is a problem of great interest for environmental monitoring, and is challenging due to several aspects. Firstly, the numerical estimation of the scalar dispersion in a turbulent flow requires significant computational resources. Secondly, in actual practice, only a limited number of observations are available, which generally makes the corresponding inverse problem ill-posed. Ensemble-based variational data assimilation techniques are adopted to solve the problem of scalar source localization in a turbulent channel flow at Reτ = 180 . This approach combines the components of variational data assimilation and ensemble Kalman filtering, and inherits the robustness from the former and the ease of implementation from the latter. An ensemble-based methodology for optimal sensor placement is also proposed in order to improve the condition of the inverse problem, which enhances the performances of the data assimilation scheme. This work has been partially funded by the Office of Naval Research (Grant N00014-16-1-2542) and by the National Science Foundation (Grant 1461870).

Cockpit Accommodation Assessment of the Bell 412CF Helicopter (Evaluation du Poste de Pilotage de l’Hellcoptere Bell 412CF)

DTIC Science & Technology

2009-12-01

Research, Ottawa , 1998 as issued jointly by the Canadian Institutes of Health Research, the Natural Sciences and Engineering Research Council of Canada...Flight Rules ) skills. Nine Bell 412CF helicopters were produced from existing CH-146 Griffons, which posed technical challenges. One such compromise was...IFR (Instrument Flight Rules ) skills. Nine Bell 412CF helicopters were produced from existing CH-146 Griffons, which posed technical challenges. One

Single leg balancing in ballet: effects of shoe conditions and poses.

PubMed

Lobo da Costa, Paula H; Azevedo Nora, Fernanda G S; Vieira, Marcus Fraga; Bosch, Kerstin; Rosenbaum, Dieter

2013-03-01

The purpose of this study was to describe the effects of lower limb positioning and shoe conditions on stability levels of selected single leg ballet poses performed in demi-pointe position. Fourteen female non-professional ballet dancers (mean age of 18.4±2.8 years and mean body mass index of 21.5±2.8kg/m(2)) who had practiced ballet for at least seven years, without any musculoskeletal impairment volunteered to participate in this study. A capacitive pressure platform allowed for the assessment of center of pressure variables related to the execution of three single leg ballet poses in demi pointé position: attitude devant, attitude derriére, and attitude a la second. Peak pressures, contact areas, COP oscillation areas, anterior-posterior and medio-lateral COP oscillations and velocities were compared between two shoe conditions (barefoot versus slippers) and among the different poses. Barefoot performances produced more stable poses with significantly higher plantar contact areas, smaller COP oscillation areas and smaller anterior-posterior COP oscillations. COP oscillation areas, anterior-posterior COP oscillations and medio-lateral COP velocities indicated that attitude a la second is the least challenging and attitude derriére the most challenging pose. Copyright © 2012 Elsevier B.V. All rights reserved.

Global Climate Change and the Mitigation Challenge

EPA Science Inventory

Book edited by Frank Princiotta titled Global Climate Change--The Technology Challenge Transparent modeling tools and the most recent literature are used, to quantify the challenge posed by climate change and potential technological remedies. The chapter examines forces driving ...

[Evaluation of Educational Effect of Problem-Posing System in Nursing Processing Study].

PubMed

Tsuji, Keiko; Takano, Yasuomi; Yamakawa, Hiroto; Kaneko, Daisuke; Takai, Kiyako; Kodama, Hiromi; Hagiwara, Tomoko; Komatsugawa, Hiroshi

2015-09-01

The nursing processing study is generally difficult, because it is important for nursing college students to understand knowledge and utilize it. We have developed an integrated system to understand, utilize, and share knowledge. We added a problem-posing function to this system, and expected that students would deeply understand the nursing processing study through the new system. This system consisted of four steps: create a problem, create an answer input section, create a hint, and verification. Nursing students created problems related to nursing processing by this system. When we gave a lecture on the nursing processing for second year students of A university, we tried to use the creating problem function of this system. We evaluated the effect by the number of problems and the contents of the created problem, that is, whether the contents consisted of a lecture stage or not. We also evaluated the correlation between those and regular examination and report scores. We derived the following: 1. weak correlation between the number of created problems and report score (r=0.27), 2. significant differences between regular examination and report scores of students who created problems corresponding to the learning stage, and those of students who created problems not corresponding to it (P<0.05). From these results, problem-posing is suggested to be effective to fix and utilize knowledge in the lecture of nursing processing theory.

The Effect of Problem Posing Oriented Analyses-II Course on the Attitudes toward Mathematics and Mathematics Self-Efficacy of Elementary Prospective Mathematics Teachers

ERIC Educational Resources Information Center

Akay, Hayri; Boz, Nihat

2010-01-01

Research on mathematics teaching and learning has recently focused on affective variables, which were found to play an essential role that influences behaviour and learning. Despite its importance, problem posing has not yet received the attention it warrants from the mathematics education community. Perceived self-efficacy beliefs have been found…

Joint Model and Parameter Dimension Reduction for Bayesian Inversion Applied to an Ice Sheet Flow Problem

NASA Astrophysics Data System (ADS)

Ghattas, O.; Petra, N.; Cui, T.; Marzouk, Y.; Benjamin, P.; Willcox, K.

2016-12-01

Model-based projections of the dynamics of the polar ice sheets play a central role in anticipating future sea level rise. However, a number of mathematical and computational challenges place significant barriers on improving predictability of these models. One such challenge is caused by the unknown model parameters (e.g., in the basal boundary conditions) that must be inferred from heterogeneous observational data, leading to an ill-posed inverse problem and the need to quantify uncertainties in its solution. In this talk we discuss the problem of estimating the uncertainty in the solution of (large-scale) ice sheet inverse problems within the framework of Bayesian inference. Computing the general solution of the inverse problem--i.e., the posterior probability density--is intractable with current methods on today's computers, due to the expense of solving the forward model (3D full Stokes flow with nonlinear rheology) and the high dimensionality of the uncertain parameters (which are discretizations of the basal sliding coefficient field). To overcome these twin computational challenges, it is essential to exploit problem structure (e.g., sensitivity of the data to parameters, the smoothing property of the forward model, and correlations in the prior). To this end, we present a data-informed approach that identifies low-dimensional structure in both parameter space and the forward model state space. This approach exploits the fact that the observations inform only a low-dimensional parameter space and allows us to construct a parameter-reduced posterior. Sampling this parameter-reduced posterior still requires multiple evaluations of the forward problem, therefore we also aim to identify a low dimensional state space to reduce the computational cost. To this end, we apply a proper orthogonal decomposition (POD) approach to approximate the state using a low-dimensional manifold constructed using ``snapshots'' from the parameter reduced posterior, and the discrete empirical interpolation method (DEIM) to approximate the nonlinearity in the forward problem. We show that using only a limited number of forward solves, the resulting subspaces lead to an efficient method to explore the high-dimensional posterior.

Predicting the affinity of Farnesoid X Receptor ligands through a hierarchical ranking protocol: a D3R Grand Challenge 2 case study

NASA Astrophysics Data System (ADS)

Réau, Manon; Langenfeld, Florent; Zagury, Jean-François; Montes, Matthieu

2018-01-01

The Drug Design Data Resource (D3R) Grand Challenges are blind contests organized to assess the state-of-the-art methods accuracy in predicting binding modes and relative binding free energies of experimentally validated ligands for a given target. The second stage of the D3R Grand Challenge 2 (GC2) was focused on ranking 102 compounds according to their predicted affinity for Farnesoid X Receptor. In this task, our workflow was ranked 5th out of the 77 submissions in the structure-based category. Our strategy consisted in (1) a combination of molecular docking using AutoDock 4.2 and manual edition of available structures for binding poses generation using SeeSAR, (2) the use of HYDE scoring for pose selection, and (3) a hierarchical ranking using HYDE and MM/GBSA. In this report, we detail our pose generation and ligands ranking protocols and provide guidelines to be used in a prospective computer aided drug design program.

Will learning to solve one-step equations pose a challenge to 8th grade students?

NASA Astrophysics Data System (ADS)

Ngu, Bing Hiong; Phan, Huy P.

2017-08-01

Assimilating multiple interactive elements simultaneously in working memory to allow understanding to occur, while solving an equation, would impose a high cognitive load. Element interactivity arises from the interaction between elements within and across operational and relational lines. Moreover, operating with special features (e.g. negative pronumeral) poses additional challenge to master equation solving skills. In an experiment, 41 8th grade students (girls = 16, boys = 25) sat for a pre-test, attended a session about equation solving, completed an acquisition phase which constituted the main intervention and were tested again in a post-test. The results showed that at post-test, students performed better on one-step equations tapping low rather than high element interactivity knowledge. In addition, students performed better on those one-step equations that contained no special features. Thus, both the degree of element interactivity and the operation with special features affect the challenge posed to 8th grade students on learning how to solve one-step equations.

A review of cooperative and uncooperative spacecraft pose determination techniques for close-proximity operations

NASA Astrophysics Data System (ADS)

Opromolla, Roberto; Fasano, Giancarmine; Rufino, Giancarlo; Grassi, Michele

2017-08-01

The capability of an active spacecraft to accurately estimate its relative position and attitude (pose) with respect to an active/inactive, artificial/natural space object (target) orbiting in close-proximity is required to carry out various activities like formation flying, on-orbit servicing, active debris removal, and space exploration. According to the specific mission scenario, the pose determination task involves both theoretical and technological challenges related to the search for the most suitable algorithmic solution and sensor architecture, respectively. As regards the latter aspect, electro-optical sensors represent the best option as their use is compatible with mass and power limitation of micro and small satellites, and their measurements can be processed to estimate all the pose parameters. Overall, the degree of complexity of the challenges related to pose determination largely varies depending on the nature of the targets, which may be actively/passively cooperative, uncooperative but known, or uncooperative and unknown space objects. In this respect, while cooperative pose determination has been successfully demonstrated in orbit, the uncooperative case is still under study by universities, research centers, space agencies and private companies. However, in both the cases, the demand for space applications involving relative navigation maneuvers, also in close-proximity, for which pose determination capabilities are mandatory, is significantly increasing. In this framework, a review of state-of-the-art techniques and algorithms developed in the last decades for cooperative and uncooperative pose determination by processing data provided by electro-optical sensors is herein presented. Specifically, their main advantages and drawbacks in terms of achieved performance, computational complexity, and sensitivity to variability of pose and target geometry, are highlighted.

Electronic waste - an emerging threat to the environment of urban India.

PubMed

Needhidasan, Santhanam; Samuel, Melvin; Chidambaram, Ramalingam

2014-01-20

Electronic waste or e-waste is one of the emerging problems in developed and developing countries worldwide. It comprises of a multitude of components with valuable materials, some containing toxic substances, that can have an adverse impact on human health and the environment. Previous studies show that India has generated 0.4 million tons of e-waste in 2010 which may increase to 0.5 to 0.6 million tons by 2013-2014. Coupled with lack of appropriate infrastructural facilities and procedures for its disposal and recycling have posed significant importance for e-waste management in India. In general, e-waste is generated through recycling of e-waste and also from dumping of these wastes from other countries. More of these wastes are ending up in dumping yards and recycling centers, posing a new challenge to the environment and policy makers as well. In general electronic gadgets are meant to make our lives happier and simpler, but the toxicity it contains, their disposal and recycling becomes a health nightmare. Most of the users are unaware of the potential negative impact of rapidly increasing use of computers, monitors, and televisions. This review article provides a concise overview of India's current e-waste scenario, namely magnitude of the problem, environmental and health hazards, current disposal, recycling operations and mechanisms to improve the condition for better environment.

Electronic waste – an emerging threat to the environment of urban India

PubMed Central

2014-01-01

Electronic waste or e-waste is one of the emerging problems in developed and developing countries worldwide. It comprises of a multitude of components with valuable materials, some containing toxic substances, that can have an adverse impact on human health and the environment. Previous studies show that India has generated 0.4 million tons of e-waste in 2010 which may increase to 0.5 to 0.6 million tons by 2013–2014. Coupled with lack of appropriate infrastructural facilities and procedures for its disposal and recycling have posed significant importance for e-waste management in India. In general, e-waste is generated through recycling of e-waste and also from dumping of these wastes from other countries. More of these wastes are ending up in dumping yards and recycling centers, posing a new challenge to the environment and policy makers as well. In general electronic gadgets are meant to make our lives happier and simpler, but the toxicity it contains, their disposal and recycling becomes a health nightmare. Most of the users are unaware of the potential negative impact of rapidly increasing use of computers, monitors, and televisions. This review article provides a concise overview of India’s current e-waste scenario, namely magnitude of the problem, environmental and health hazards, current disposal, recycling operations and mechanisms to improve the condition for better environment. PMID:24444377

Docking pose selection by interaction pattern graph similarity: application to the D3R grand challenge 2015

NASA Astrophysics Data System (ADS)

Slynko, Inna; Da Silva, Franck; Bret, Guillaume; Rognan, Didier

2016-09-01

High affinity ligands for a given target tend to share key molecular interactions with important anchoring amino acids and therefore often present quite conserved interaction patterns. This simple concept was formalized in a topological knowledge-based scoring function (GRIM) for selecting the most appropriate docking poses from previously X-rayed interaction patterns. GRIM first converts protein-ligand atomic coordinates (docking poses) into a simple 3D graph describing the corresponding interaction pattern. In a second step, proposed graphs are compared to that found from template structures in the Protein Data Bank. Last, all docking poses are rescored according to an empirical score (GRIMscore) accounting for overlap of maximum common subgraphs. Taking the opportunity of the public D3R Grand Challenge 2015, GRIM was used to rescore docking poses for 36 ligands (6 HSP90α inhibitors, 30 MAP4K4 inhibitors) prior to the release of the corresponding protein-ligand X-ray structures. When applied to the HSP90α dataset, for which many protein-ligand X-ray structures are already available, GRIM provided very high quality solutions (mean rmsd = 1.06 Å, n = 6) as top-ranked poses, and significantly outperformed a state-of-the-art scoring function. In the case of MAP4K4 inhibitors, for which preexisting 3D knowledge is scarce and chemical diversity is much larger, the accuracy of GRIM poses decays (mean rmsd = 3.18 Å, n = 30) although GRIM still outperforms an energy-based scoring function. GRIM rescoring appears to be quite robust with comparison to the other approaches competing for the same challenge (42 submissions for the HSP90 dataset, 27 for the MAP4K4 dataset) as it ranked 3rd and 2nd respectively, for the two investigated datasets. The rescoring method is quite simple to implement, independent on a docking engine, and applicable to any target for which at least one holo X-ray structure is available.

SMEX-Lite Modular Solar Array Architecture

NASA Technical Reports Server (NTRS)

Lyons, John W.; Day, John (Technical Monitor)

2002-01-01

The NASA Small Explorer (SMEX) missions have typically had three years between mission definition and launch. This short schedule has posed significant challenges with respect to solar array design and procurement. Typically, the solar panel geometry is frozen prior to going out with a procurement. However, with the SMEX schedule, it has been virtually impossible to freeze the geometry in time to avoid scheduling problems with integrating the solar panels to the spacecraft. A modular solar array architecture was developed to alleviate this problem. This approach involves procuring sufficient modules for multiple missions and assembling the modules onto a solar array framework that is unique to each mission. The modular approach removes the solar array from the critical path of the SMEX integration and testing schedule. It also reduces the cost per unit area of the solar arrays and facilitates the inclusion of experiments involving new solar cell or panel technologies in the SMEX missions.

A frequency-domain seismic blind deconvolution based on Gini correlations

NASA Astrophysics Data System (ADS)

Wang, Zhiguo; Zhang, Bing; Gao, Jinghuai; Huo Liu, Qing

2018-02-01

In reflection seismic processing, the seismic blind deconvolution is a challenging problem, especially when the signal-to-noise ratio (SNR) of the seismic record is low and the length of the seismic record is short. As a solution to this ill-posed inverse problem, we assume that the reflectivity sequence is independent and identically distributed (i.i.d.). To infer the i.i.d. relationships from seismic data, we first introduce the Gini correlations (GCs) to construct a new criterion for the seismic blind deconvolution in the frequency-domain. Due to a unique feature, the GCs are robust in their higher tolerance of the low SNR data and less dependent on record length. Applications of the seismic blind deconvolution based on the GCs show their capacity in estimating the unknown seismic wavelet and the reflectivity sequence, whatever synthetic traces or field data, even with low SNR and short sample record.

Student treatment on clerkships based on their specialty interests.

PubMed

Woolley, Douglas C; Paolo, Anthony M; Bonaminio, Giulia A; Moser, Scott E

2006-01-01

Student clerkship experiences may suffer if teachers are not sympathetic to students' clinical interests. In this study, we quantified these experiences, compared reports of primary care and focused specialty students, and identified clerkships and teachers that posed special problems. Students starting their 4th year at 6 schools completed a survey. The response rate was 75%. Students reported that these experiences, which were provoked by their clinical interests, were common: hearing deprecating comments about their interests, being denied learning opportunities, receiving lower evaluations, being discouraged from pursing their interests, and needing to be evasive for self-protection. Primary care students reported less mistreatment than focused specialty students. Students identified some clerkships and types of teachers as special problem sources. Students reported mistreatment triggered by clinical interests at twice the national rates for mistreatment triggered by race or sex. Such mistreatment is common and challenges medical schools to ensure that students are treated well regardless of their career aspirations.

Relationships between medicine and industry: approaches to the problem of conflicts of interest.

PubMed

Raad, Raymond; Appelbaum, Paul S

2012-01-01

Relationships between physicians and industry are prevalent in medical education, clinical practice, and research, as well as at the level of medical institutions. These relationships can be valuable for the advancement of medicine but have also received increased scrutiny in recent years because they create conflicts of interest that pose a risk of biasing the judgments of physicians. Responses to these conflicts of interest by medical institutions, journals, and governments have utilized four main tools: education, disclosure, management, and prohibition. Each of the four has its advantages and drawbacks. Medicine faces the challenge of tailoring the use of these tools to minimize the risk of bias while allowing useful medical-industry collaborations to proceed. Viewing the dilemmas created by physicians' relationships with industry as a version of the principal-agent problem, which is much discussed by economists, may help in developing creative approaches to these issues.

Non-rigid image registration using graph-cuts.

PubMed

Tang, Tommy W H; Chung, Albert C S

2007-01-01

Non-rigid image registration is an ill-posed yet challenging problem due to its supernormal high degree of freedoms and inherent requirement of smoothness. Graph-cuts method is a powerful combinatorial optimization tool which has been successfully applied into image segmentation and stereo matching. Under some specific constraints, graph-cuts method yields either a global minimum or a local minimum in a strong sense. Thus, it is interesting to see the effects of using graph-cuts in non-rigid image registration. In this paper, we formulate non-rigid image registration as a discrete labeling problem. Each pixel in the source image is assigned a displacement label (which is a vector) indicating which position in the floating image it is spatially corresponding to. A smoothness constraint based on first derivative is used to penalize sharp changes in displacement labels across pixels. The whole system can be optimized by using the graph-cuts method via alpha-expansions. We compare 2D and 3D registration results of our method with two state-of-the-art approaches. It is found that our method is more robust to different challenging non-rigid registration cases with higher registration accuracy.

Expert-guided evolutionary algorithm for layout design of complex space stations

NASA Astrophysics Data System (ADS)

Qian, Zhiqin; Bi, Zhuming; Cao, Qun; Ju, Weiguo; Teng, Hongfei; Zheng, Yang; Zheng, Siyu

2017-08-01

The layout of a space station should be designed in such a way that different equipment and instruments are placed for the station as a whole to achieve the best overall performance. The station layout design is a typical nondeterministic polynomial problem. In particular, how to manage the design complexity to achieve an acceptable solution within a reasonable timeframe poses a great challenge. In this article, a new evolutionary algorithm has been proposed to meet such a challenge. It is called as the expert-guided evolutionary algorithm with a tree-like structure decomposition (EGEA-TSD). Two innovations in EGEA-TSD are (i) to deal with the design complexity, the entire design space is divided into subspaces with a tree-like structure; it reduces the computation and facilitates experts' involvement in the solving process. (ii) A human-intervention interface is developed to allow experts' involvement in avoiding local optimums and accelerating convergence. To validate the proposed algorithm, the layout design of one-space station is formulated as a multi-disciplinary design problem, the developed algorithm is programmed and executed, and the result is compared with those from other two algorithms; it has illustrated the superior performance of the proposed EGEA-TSD.

Clone tag detection in distributed RFID systems

PubMed Central

Kamaludin, Hazalila; Mahdin, Hairulnizam

2018-01-01

Although Radio Frequency Identification (RFID) is poised to displace barcodes, security vulnerabilities pose serious challenges for global adoption of the RFID technology. Specifically, RFID tags are prone to basic cloning and counterfeiting security attacks. A successful cloning of the RFID tags in many commercial applications can lead to many serious problems such as financial losses, brand damage, safety and health of the public. With many industries such as pharmaceutical and businesses deploying RFID technology with a variety of products, it is important to tackle RFID tag cloning problem and improve the resistance of the RFID systems. To this end, we propose an approach for detecting cloned RFID tags in RFID systems with high detection accuracy and minimal overhead thus overcoming practical challenges in existing approaches. The proposed approach is based on consistency of dual hash collisions and modified count-min sketch vector. We evaluated the proposed approach through extensive experiments and compared it with existing baseline approaches in terms of execution time and detection accuracy under varying RFID tag cloning ratio. The results of the experiments show that the proposed approach outperforms the baseline approaches in cloned RFID tag detection accuracy. PMID:29565982

Methamphetamine-associated psychosis: a new health challenge in Iran

PubMed Central

2013-01-01

The rapidly growing popularity of methamphetamine use in Iran has posed a new health challenge to the Iranian health sector. Methamphetamine-associated psychosis (MAP) has been frequently reported in Iran in recent years. Although methamphetamine use and MAP are considerable health problems in Iran but there is still a need to conduct epidemiological studies on the prevalence of MAP and its health-related problems. The present paper emphasizes that health policy makers should consider the immediate needs of drug users, their families and the community to be informed about the detrimental health effects associated with MAP. Although MAP could be managed by prescribing benzodiazepines and psychiatric medications but the most effective regime for stabilizing patients with MAP still needs to be studied in Iran. Constant collaborations among psychiatric services and outpatient psychotherapeutic services should be established to successfully manage MAP in Iran. Iranian clinicians especially emergency medicine specialists should be informed about the differences between the two forms of transient and recurrent MAP in order to implement appropriate pharmacological therapies to manage MAP. It is hoped that special training courses are designed and implemented by health policy makers to inform clinicians, health providers and especially emergency medicine specialists to effectively deal with MAP. PMID:23577655

Opportunities and obstacles for deep learning in biology and medicine.

PubMed

Ching, Travers; Himmelstein, Daniel S; Beaulieu-Jones, Brett K; Kalinin, Alexandr A; Do, Brian T; Way, Gregory P; Ferrero, Enrico; Agapow, Paul-Michael; Zietz, Michael; Hoffman, Michael M; Xie, Wei; Rosen, Gail L; Lengerich, Benjamin J; Israeli, Johnny; Lanchantin, Jack; Woloszynek, Stephen; Carpenter, Anne E; Shrikumar, Avanti; Xu, Jinbo; Cofer, Evan M; Lavender, Christopher A; Turaga, Srinivas C; Alexandari, Amr M; Lu, Zhiyong; Harris, David J; DeCaprio, Dave; Qi, Yanjun; Kundaje, Anshul; Peng, Yifan; Wiley, Laura K; Segler, Marwin H S; Boca, Simina M; Swamidass, S Joshua; Huang, Austin; Gitter, Anthony; Greene, Casey S

2018-04-01

Deep learning describes a class of machine learning algorithms that are capable of combining raw inputs into layers of intermediate features. These algorithms have recently shown impressive results across a variety of domains. Biology and medicine are data-rich disciplines, but the data are complex and often ill-understood. Hence, deep learning techniques may be particularly well suited to solve problems of these fields. We examine applications of deep learning to a variety of biomedical problems-patient classification, fundamental biological processes and treatment of patients-and discuss whether deep learning will be able to transform these tasks or if the biomedical sphere poses unique challenges. Following from an extensive literature review, we find that deep learning has yet to revolutionize biomedicine or definitively resolve any of the most pressing challenges in the field, but promising advances have been made on the prior state of the art. Even though improvements over previous baselines have been modest in general, the recent progress indicates that deep learning methods will provide valuable means for speeding up or aiding human investigation. Though progress has been made linking a specific neural network's prediction to input features, understanding how users should interpret these models to make testable hypotheses about the system under study remains an open challenge. Furthermore, the limited amount of labelled data for training presents problems in some domains, as do legal and privacy constraints on work with sensitive health records. Nonetheless, we foresee deep learning enabling changes at both bench and bedside with the potential to transform several areas of biology and medicine. © 2018 The Authors.

Prediction of binding poses to FXR using multi-targeted docking combined with molecular dynamics and enhanced sampling

NASA Astrophysics Data System (ADS)

Bhakat, Soumendranath; Åberg, Emil; Söderhjelm, Pär

2018-01-01

Advanced molecular docking methods often aim at capturing the flexibility of the protein upon binding to the ligand. In this study, we investigate whether instead a simple rigid docking method can be applied, if combined with multiple target structures to model the backbone flexibility and molecular dynamics simulations to model the sidechain and ligand flexibility. The methods are tested for the binding of 35 ligands to FXR as part of the first stage of the Drug Design Data Resource (D3R) Grand Challenge 2 blind challenge. The results show that the multiple-target docking protocol performs surprisingly well, with correct poses found for 21 of the ligands. MD simulations started on the docked structures are remarkably stable, but show almost no tendency of refining the structure closer to the experimentally found binding pose. Reconnaissance metadynamics enhances the exploration of new binding poses, but additional collective variables involving the protein are needed to exploit the full potential of the method.

Prediction of binding poses to FXR using multi-targeted docking combined with molecular dynamics and enhanced sampling.

PubMed

Bhakat, Soumendranath; Åberg, Emil; Söderhjelm, Pär

2018-01-01

Advanced molecular docking methods often aim at capturing the flexibility of the protein upon binding to the ligand. In this study, we investigate whether instead a simple rigid docking method can be applied, if combined with multiple target structures to model the backbone flexibility and molecular dynamics simulations to model the sidechain and ligand flexibility. The methods are tested for the binding of 35 ligands to FXR as part of the first stage of the Drug Design Data Resource (D3R) Grand Challenge 2 blind challenge. The results show that the multiple-target docking protocol performs surprisingly well, with correct poses found for 21 of the ligands. MD simulations started on the docked structures are remarkably stable, but show almost no tendency of refining the structure closer to the experimentally found binding pose. Reconnaissance metadynamics enhances the exploration of new binding poses, but additional collective variables involving the protein are needed to exploit the full potential of the method.

One Answer to "What Is Calculus?"

ERIC Educational Resources Information Center

Shilgalis, Thomas W.

1979-01-01

A number of questions are posed that can be answered with the aid of calculus. These include best value problems, best shape problems, problems involving integration, and growth and decay problems. (MP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oleinikov, A. I., E-mail: a.i.oleinikov@mail.ru; Bormotin, K. S., E-mail: cvmi@knastu.ru

It is shown that inverse problems of steady-state creep bending of plates in both the geometrically linear and nonlinear formulations can be represented in a variational formulation. Steady-state values of the obtained functionals corresponding to the solutions of the problems of inelastic deformation and springback are determined by applying a finite element procedure to the functionals. Optimal laws of creep deformation are formulated using the criterion of minimizing damage in the functionals of the inverse problems. The formulated problems are reduced to the problems solved by the finite element method using MSC.Marc software. Currently, forming of light metals poses tremendousmore » challenges due to their low ductility at room temperature and their unusual deformation characteristics at hot-cold work: strong asymmetry between tensile and compressive behavior, and a very pronounced anisotropy. We used the constitutive models of steady-state creep of initially transverse isotropy structural materials the kind of the stress state has influence. The paper gives basics of the developed computer-aided system of design, modeling, and electronic simulation targeting the processes of manufacture of wing integral panels. The modeling results can be used to calculate the die tooling, determine the panel processibility, and control panel rejection in the course of forming.« less

Some challenges in designing a lunar, Martian, or microgravity CELSS.

PubMed

Salisbury, F B

1992-01-01

The design of a bioregenerative life-support system (a Controlled Ecological Life-Support System or CELSS) for long-duration stays on the moon, Mars, or in a space craft poses formidable problems in engineering and in theory. Technological (hardware) problems include: (1) Creation and control of gas composition and pressure, temperature, light, humidity, and air circulation, especially in microgravity to 1/3 xg and in the vacuum of space. Light (energy demanding), CO2 levels, and the rooting media are special problems for plants. (2) Developing specialized equipment for food preparation. (3) Equipment development for waste recycling. (4) Development of computer systems for environmental monitoring and control as well as several other functions. Problems of theory (software) include: (1) Determining crop species and cultivars (some bred especially for CELSS). (2) Optimum environments and growing and harvesting techniques for each crop. (3) Best and most efficient food-preparation techniques and required equipment. (4) Best and most efficient waste-recycling techniques and equipment. This topic includes questions about the extent of closure, resupply, and waste storage. (5) How to achieve long-term stability. (6) How to avoid catastrophic failures--and how to recover from near-catastrophic failures (for example, plant diseases). Many problems must be solved.

Self-worth, perceived competence, and behaviour problems in children with cerebral palsy.

PubMed

Schuengel, Carlo; Voorman, Jeanine; Stolk, Joop; Dallmeijer, Annet; Vermeer, Adri; Becher, Jules

2006-10-30

To examine the relevance of physical disabilities for self-worth and perceived competence in children with cerebral palsy (CP), and to examine associations between behaviour problems and self-worth and perceived competence. The Harter scales for self-worth and perceived competence and a new scale for perceived motor competence were used in a sample of 80 children with CP. Their motor functioning was assessed with the Gross Motor Functioning Measure (GMFM) and behaviour problems with the Child Behaviour Check List administered to parents. Self-worth and perceived competence for children with CP were comparable to the Dutch norm sample, except for perceived athletic competence. Within the CP sample, the GMFM showed a domain-specific effect on perceived motor competence. In the multivariate analysis, internalizing problems were associated negatively with all perceived competence scales and self-worth, whereas aggression was positively associated with perceived motor competence, physical appearance, and self-worth. Children with CP appear resilient against challenges posed to their self-worth caused by their disabilities. The relevance of the physical disability appears to be domain-specific. For internalizing problems and aggression, different theoretical models are needed to account for their associations with self-worth and perceived competence.

Some challenges in designing a lunar, Martian, or microgravity CELSS

NASA Astrophysics Data System (ADS)

Salisbury, Frank B.

The design of a bioregenerative life-support system (a Controlled Ecological Life-Support System or CELSS) for long-duration stays on the moon, Mars, or in a space craft poses formidable problems in engineering and in theory. Technological (hardware) problems include: (1) Creation and control of gas composition and pressure, temperature, light, humidity, and air circulation, especially in microgravity to 1/3xg and in the vacuum of space. Light (energy demanding), CO 2 levels, and the rooting media are special problems for plants. (2) Developing specialized equipment for food preparation. (3) Equipment development for waste recycling. (4) Development of computer systems for environmental monitoring and control as well as several other functions. Problems of theory (software) include: (1) Determining crop species and cultivars (some bred especially for CELSS). (2) Optimum environments and growing and harvesting techniques for each crop. (3) Best and most efficient food-preparation techniques and required equipment. (4) Best and most efficient waste-recycling techniques and equipment. This topic includes questions about the extent of closure, resupply, and waste storage. (5) How to achieve long-term stability. (6) How to avoid catastrophic failures-and how to recover from near-catastrophic failures (for example, plant diseases). Many problems must be solved.

Group search optimiser-based optimal bidding strategies with no Karush-Kuhn-Tucker optimality conditions

NASA Astrophysics Data System (ADS)

Yadav, Naresh Kumar; Kumar, Mukesh; Gupta, S. K.

2017-03-01

General strategic bidding procedure has been formulated in the literature as a bi-level searching problem, in which the offer curve tends to minimise the market clearing function and to maximise the profit. Computationally, this is complex and hence, the researchers have adopted Karush-Kuhn-Tucker (KKT) optimality conditions to transform the model into a single-level maximisation problem. However, the profit maximisation problem with KKT optimality conditions poses great challenge to the classical optimisation algorithms. The problem has become more complex after the inclusion of transmission constraints. This paper simplifies the profit maximisation problem as a minimisation function, in which the transmission constraints, the operating limits and the ISO market clearing functions are considered with no KKT optimality conditions. The derived function is solved using group search optimiser (GSO), a robust population-based optimisation algorithm. Experimental investigation is carried out on IEEE 14 as well as IEEE 30 bus systems and the performance is compared against differential evolution-based strategic bidding, genetic algorithm-based strategic bidding and particle swarm optimisation-based strategic bidding methods. The simulation results demonstrate that the obtained profit maximisation through GSO-based bidding strategies is higher than the other three methods.

Pose-free structure from motion using depth from motion constraints.

PubMed

Zhang, Ji; Boutin, Mireille; Aliaga, Daniel G

2011-10-01

Structure from motion (SFM) is the problem of recovering the geometry of a scene from a stream of images taken from unknown viewpoints. One popular approach to estimate the geometry of a scene is to track scene features on several images and reconstruct their position in 3-D. During this process, the unknown camera pose must also be recovered. Unfortunately, recovering the pose can be an ill-conditioned problem which, in turn, can make the SFM problem difficult to solve accurately. We propose an alternative formulation of the SFM problem with fixed internal camera parameters known a priori. In this formulation, obtained by algebraic variable elimination, the external camera pose parameters do not appear. As a result, the problem is better conditioned in addition to involving much fewer variables. Variable elimination is done in three steps. First, we take the standard SFM equations in projective coordinates and eliminate the camera orientations from the equations. We then further eliminate the camera center positions. Finally, we also eliminate all 3-D point positions coordinates, except for their depths with respect to the camera center, thus obtaining a set of simple polynomial equations of degree two and three. We show that, when there are merely a few points and pictures, these "depth-only equations" can be solved in a global fashion using homotopy methods. We also show that, in general, these same equations can be used to formulate a pose-free cost function to refine SFM solutions in a way that is more accurate than by minimizing the total reprojection error, as done when using the bundle adjustment method. The generalization of our approach to the case of varying internal camera parameters is briefly discussed. © 2011 IEEE

Occupational risks and challenges of seafaring.

PubMed

Oldenburg, Marcus; Baur, Xaver; Schlaich, Clara

2010-01-01

Seafarers are exposed to a high diversity of occupational health hazards onboard ships. The aim of this article is to present a survey of the current, most important hazards in seafaring including recommendations on measures how to deal with these problems. The review is based on maritime expert opinions as well a PubMed analysis related to the occupational risks of seafaring. Despite recent advances in injury prevention, accidents due to harmful working and living conditions at sea and of non-observance of safety rules remain a main cause of injury and death. Mortality in seafaring from cardiovascular diseases (CVD) is mainly caused by increased risks and impaired treatment options of CVD at sea. Further, shipboard stress and high demand may lead to fatigue and isolation which have an impact on the health of onboard seafarers. Communicable diseases in seafaring remain an occupational problem. Exposures to hazardous substances and UV-light are important health risks onboard ships. Because of harsh working conditions onboard including environmental conditions, sufficient recreational activities are needed for the seafarers' compensation both onboard and ashore. However, in reality there is often a lack of leisure time possibilities. Seafaring is still an occupation with specific work-related risks. Thus, a further reduction of occupational hazards aboard ships is needed and poses a challenge for maritime health specialists and stakeholders. Nowadays, maritime medicine encompasses a broad field of workplaces with different job-related challenges.

Coupled variational formulations of linear elasticity and the DPG methodology

NASA Astrophysics Data System (ADS)

Fuentes, Federico; Keith, Brendan; Demkowicz, Leszek; Le Tallec, Patrick

2017-11-01

This article presents a general approach akin to domain-decomposition methods to solve a single linear PDE, but where each subdomain of a partitioned domain is associated to a distinct variational formulation coming from a mutually well-posed family of broken variational formulations of the original PDE. It can be exploited to solve challenging problems in a variety of physical scenarios where stability or a particular mode of convergence is desired in a part of the domain. The linear elasticity equations are solved in this work, but the approach can be applied to other equations as well. The broken variational formulations, which are essentially extensions of more standard formulations, are characterized by the presence of mesh-dependent broken test spaces and interface trial variables at the boundaries of the elements of the mesh. This allows necessary information to be naturally transmitted between adjacent subdomains, resulting in coupled variational formulations which are then proved to be globally well-posed. They are solved numerically using the DPG methodology, which is especially crafted to produce stable discretizations of broken formulations. Finally, expected convergence rates are verified in two different and illustrative examples.

A machine learning approach for ranking clusters of docked protein‐protein complexes by pairwise cluster comparison

PubMed Central

Pfeiffenberger, Erik; Chaleil, Raphael A.G.; Moal, Iain H.

2017-01-01

ABSTRACT Reliable identification of near‐native poses of docked protein–protein complexes is still an unsolved problem. The intrinsic heterogeneity of protein–protein interactions is challenging for traditional biophysical or knowledge based potentials and the identification of many false positive binding sites is not unusual. Often, ranking protocols are based on initial clustering of docked poses followed by the application of an energy function to rank each cluster according to its lowest energy member. Here, we present an approach of cluster ranking based not only on one molecular descriptor (e.g., an energy function) but also employing a large number of descriptors that are integrated in a machine learning model, whereby, an extremely randomized tree classifier based on 109 molecular descriptors is trained. The protocol is based on first locally enriching clusters with additional poses, the clusters are then characterized using features describing the distribution of molecular descriptors within the cluster, which are combined into a pairwise cluster comparison model to discriminate near‐native from incorrect clusters. The results show that our approach is able to identify clusters containing near‐native protein–protein complexes. In addition, we present an analysis of the descriptors with respect to their power to discriminate near native from incorrect clusters and how data transformations and recursive feature elimination can improve the ranking performance. Proteins 2017; 85:528–543. © 2016 Wiley Periodicals, Inc. PMID:27935158

Robustly Aligning a Shape Model and Its Application to Car Alignment of Unknown Pose.

PubMed

Li, Yan; Gu, Leon; Kanade, Takeo

2011-09-01

Precisely localizing in an image a set of feature points that form a shape of an object, such as car or face, is called alignment. Previous shape alignment methods attempted to fit a whole shape model to the observed data, based on the assumption of Gaussian observation noise and the associated regularization process. However, such an approach, though able to deal with Gaussian noise in feature detection, turns out not to be robust or precise because it is vulnerable to gross feature detection errors or outliers resulting from partial occlusions or spurious features from the background or neighboring objects. We address this problem by adopting a randomized hypothesis-and-test approach. First, a Bayesian inference algorithm is developed to generate a shape-and-pose hypothesis of the object from a partial shape or a subset of feature points. For alignment, a large number of hypotheses are generated by randomly sampling subsets of feature points, and then evaluated to find the one that minimizes the shape prediction error. This method of randomized subset-based matching can effectively handle outliers and recover the correct object shape. We apply this approach on a challenging data set of over 5,000 different-posed car images, spanning a wide variety of car types, lighting, background scenes, and partial occlusions. Experimental results demonstrate favorable improvements over previous methods on both accuracy and robustness.

Plant-based FRET biosensor discriminates enviornmental zinc levels

USDA-ARS?s Scientific Manuscript database

Heavy metal accumulation in the environment poses great risks to flora and fauna. However, monitoring sites prone to accumulation poses scale and economic challenges. In this study, we present and test a method for monitoring these sites using fluorescent resonance energy transfer (FRET) change in r...

Security, development and human rights: normative, legal and policy challenges for the international drug control system.

PubMed

Barrett, Damon

2010-03-01

This commentary addresses some of the challenges posed by the broader normative, legal and policy framework of the United Nations for the international drug control system. The 'purposes and principles' of the United Nations are presented and set against the threat based rhetoric of the drug control system and the negative consequences of that system. Some of the challenges posed by human rights law and norms to the international drug control system are also described, and the need for an impact assessment of the current system alongside alternative policy options is highlighted as a necessary consequence of these analyses. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Nutrition support of the pediatric patient with AIDS.

PubMed

Bentler, M; Stanish, M

1987-04-01

Maintaining optimal nutrition in the pediatric patient with Acquired Immune Deficiency Syndrome (AIDS) is challenging, but it may be one of the most effective therapies. Patients experience numerous complications that compromise nutritional status. Infection, fever, diarrhea, feeding problems, and decreased intake all contribute to malnutrition, which in turn predisposes the patient even more to infection and malabsorption. Nutrition assessment should be done routinely so that new problems may be identified and treated. High-calorie, high-protein feedings, vitamin supplementation, and, when necessary, gavage feedings or parenteral nutrition are recommended to improve nutritional status and prevent further deficits. Maintaining optimal nutrition in the pediatric patient with Acquired Immune Deficiency Syndrome (AIDS) poses a significant challenge to the health care team. Patients may experience numerous complications that compromise nutritional status. The patient is at high risk for opportunistic infections, especially of the lungs, central nervous system, gastrointestinal (GI) tract, and skin. Such infections are common causes of morbidity and mortality. Impaired nutritional status may further impair the patient's immunocompetence. A study by Kotler and Gaety demonstrated severe progressive malnutrition in adult AIDS patients, with the lowest measures of lean body mass occurring in those patients close to death at the time of the study. While no studies of children with AIDS have been done to date, we have subjectively observed feeding problems, weight loss, and malnutrition in most of the patients we have seen.

Warhead verification as inverse problem: Applications of neutron spectrum unfolding from organic-scintillator measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawrence, Chris C.; Flaska, Marek; Pozzi, Sara A.

2016-08-14

Verification of future warhead-dismantlement treaties will require detection of certain warhead attributes without the disclosure of sensitive design information, and this presents an unusual measurement challenge. Neutron spectroscopy—commonly eschewed as an ill-posed inverse problem—may hold special advantages for warhead verification by virtue of its insensitivity to certain neutron-source parameters like plutonium isotopics. In this article, we investigate the usefulness of unfolded neutron spectra obtained from organic-scintillator data for verifying a particular treaty-relevant warhead attribute: the presence of high-explosive and neutron-reflecting materials. Toward this end, several improvements on current unfolding capabilities are demonstrated: deuterated detectors are shown to have superior response-matrixmore » condition to that of standard hydrogen-base scintintillators; a novel data-discretization scheme is proposed which removes important detector nonlinearities; and a technique is described for re-parameterizing the unfolding problem in order to constrain the parameter space of solutions sought, sidestepping the inverse problem altogether. These improvements are demonstrated with trial measurements and verified using accelerator-based time-of-flight calculation of reference spectra. Then, a demonstration is presented in which the elemental compositions of low-Z neutron-attenuating materials are estimated to within 10%. These techniques could have direct application in verifying the presence of high-explosive materials in a neutron-emitting test item, as well as other for treaty verification challenges.« less

Warhead verification as inverse problem: Applications of neutron spectrum unfolding from organic-scintillator measurements

NASA Astrophysics Data System (ADS)

Lawrence, Chris C.; Febbraro, Michael; Flaska, Marek; Pozzi, Sara A.; Becchetti, F. D.

2016-08-01

Verification of future warhead-dismantlement treaties will require detection of certain warhead attributes without the disclosure of sensitive design information, and this presents an unusual measurement challenge. Neutron spectroscopy—commonly eschewed as an ill-posed inverse problem—may hold special advantages for warhead verification by virtue of its insensitivity to certain neutron-source parameters like plutonium isotopics. In this article, we investigate the usefulness of unfolded neutron spectra obtained from organic-scintillator data for verifying a particular treaty-relevant warhead attribute: the presence of high-explosive and neutron-reflecting materials. Toward this end, several improvements on current unfolding capabilities are demonstrated: deuterated detectors are shown to have superior response-matrix condition to that of standard hydrogen-base scintintillators; a novel data-discretization scheme is proposed which removes important detector nonlinearities; and a technique is described for re-parameterizing the unfolding problem in order to constrain the parameter space of solutions sought, sidestepping the inverse problem altogether. These improvements are demonstrated with trial measurements and verified using accelerator-based time-of-flight calculation of reference spectra. Then, a demonstration is presented in which the elemental compositions of low-Z neutron-attenuating materials are estimated to within 10%. These techniques could have direct application in verifying the presence of high-explosive materials in a neutron-emitting test item, as well as other for treaty verification challenges.

Practical Problems with Medication Use that Older People Experience: A Qualitative Study

PubMed Central

Notenboom, Kim; Beers, Erna; van Riet-Nales, Diana A; Egberts, Toine C G; Leufkens, Hubert G M; Jansen, Paul A F; Bouvy, Marcel L

2014-01-01

Objectives To identify the practical problems that older people experience with the daily use of their medicines and their management strategies to address these problems and to determine the potential clinical relevance thereof. Design Qualitative study with semistructured face-to-face interviews. Setting A community pharmacy and a geriatric outpatient ward. Participants Community-dwelling people aged 70 and older (N = 59). Measurements Participants were interviewed at home. Two researchers coded the reported problems and management strategies independently according to a coding scheme. An expert panel classified the potential clinical relevance of every identified practical problem and associated management strategy using a 3-point scale. Results Two hundred eleven practical problems and 184 management strategies were identified. Ninety-five percent of the participants experienced one or more practical problems with the use of their medicines: problems reading and understanding the instructions for use, handling the outer packaging, handling the immediate packaging, completing preparation before use, and taking the medicine. For 10 participants, at least one of their problems, in combination with the applied management strategy, had potential clinical consequences and 11 cases (5% of the problems) had the potential to cause moderate or severe clinical deterioration. Conclusion Older people experience a number of practical problems using their medicines, and their strategies to manage these problems are sometimes suboptimal. These problems can lead to incorrect medication use with clinically relevant consequences. The findings pose a challenge for healthcare professionals, drug developers, and regulators to diminish these problems. PMID:25516030

Inferring Small Scale Dynamics from Aircraft Measurements of Tracers

NASA Technical Reports Server (NTRS)

Sparling, L. C.; Einaudi, Franco (Technical Monitor)

2000-01-01

The millions of ER-2 and DC-8 aircraft measurements of long-lived tracers in the Upper Troposphere/Lower Stratosphere (UT/LS) hold enormous potential as a source of statistical information about subgrid scale dynamics. Extracting this information however can be extremely difficult because the measurements are made along a 1-D transect through fields that are highly anisotropic in all three dimensions. Some of the challenges and limitations posed by both the instrumentation and platform are illustrated within the context of the problem of using the data to obtain an estimate of the dissipation scale. This presentation will also include some tutorial remarks about the conditional and two-point statistics used in the analysis.

Diagrammatic routes to nonlocal correlations beyond dynamical mean field theory

NASA Astrophysics Data System (ADS)

Rohringer, G.; Hafermann, H.; Toschi, A.; Katanin, A. A.; Antipov, A. E.; Katsnelson, M. I.; Lichtenstein, A. I.; Rubtsov, A. N.; Held, K.

2018-04-01

Strong electronic correlations pose one of the biggest challenges to solid state theory. Recently developed methods that address this problem by starting with the local, eminently important correlations of dynamical mean field theory (DMFT) are reviewed. In addition, nonlocal correlations on all length scales are generated through Feynman diagrams, with a local two-particle vertex instead of the bare Coulomb interaction as a building block. With these diagrammatic extensions of DMFT long-range charge, magnetic, and superconducting fluctuations as well as (quantum) criticality can be addressed in strongly correlated electron systems. An overview is provided of the successes and results achieved, mainly for model Hamiltonians, and an outline is given of future prospects for realistic material calculations.

3D reconstruction from non-uniform point clouds via local hierarchical clustering

NASA Astrophysics Data System (ADS)

Yang, Jiaqi; Li, Ruibo; Xiao, Yang; Cao, Zhiguo

2017-07-01

Raw scanned 3D point clouds are usually irregularly distributed due to the essential shortcomings of laser sensors, which therefore poses a great challenge for high-quality 3D surface reconstruction. This paper tackles this problem by proposing a local hierarchical clustering (LHC) method to improve the consistency of point distribution. Specifically, LHC consists of two steps: 1) adaptive octree-based decomposition of 3D space, and 2) hierarchical clustering. The former aims at reducing the computational complexity and the latter transforms the non-uniform point set into uniform one. Experimental results on real-world scanned point clouds validate the effectiveness of our method from both qualitative and quantitative aspects.

The economic and social context of special populations.

PubMed

Ashford, N A

1999-01-01

Changes in both technology and international trade are altering the world economy and hence are affecting the demand and supply of labor and the nature of work and working conditions. New materials, faster and more powerful computers, electronic and mobile communications, alternative energy systems, miniaturization, robotics, and biotechnology pose new opportunities, problems, and challenges. The tremendous expansion in information-based technologies in both manufacturing and services has resulted in impressive increases in productivity and demand for new skills, but they also have brought about the displacement and de-skilling of some labor by capital, the lowering of wages, and the increase of contingent, part-time, and temporary work. Special populations, in particular, may be differentially impacted.

Visual design: a step towards multicultural health care.

PubMed

Alvarez, Juliana

2014-02-01

Standing at the crossroads of anthropology, communication, industrial design and new technology theories, this article describes the communication challenges posed during hospital emergencies resulting from linguistic and cultural differences between health care professionals and patients. In order to overcome communication barriers, the proposal of a visual solution was analyzed. Likewise, the problem was studied based on the concepts of perception, comprehension, interpretation and graphic representation according to visual culture and semiotics theories. One hundred and ffty images showing symptoms were analyzed in order to identify a pluricultural iconographic code. Results enabled to develop a list of design criteria and create the application: "My Symptoms Translator" as an option to overcome verbal language barriers and cultural differences.

Fieldwork and social science research ethics.

PubMed

Contractor, Qudsiya

2008-01-01

Fieldwork as a part of social science research brings the researcher closest to the subject of research. It is a dynamic process where there is an exchange between the researcher, participants, stakeholders, gatekeepers, the community and the larger sociopolitical context in which the research problem is located. Ethical dilemmas that surface during fieldwork often pose a unique challenge to the researcher. This paper is based on field experiences during an action research study conducted with a human rights perspective. It discusses the role conflict that researchers face during fieldwork in a situation of humanitarian crisis. It raises issues pertaining to the need to extend the ethical decision-making paradigm to address ethical dilemmas arising during the course of fieldwork.

Diet, Exercise, Behavior: The Promise and Limits of Lifestyle Change

PubMed Central

Bennett, Brian; Sothern, Melinda S.

2009-01-01

The prevalent surge in childhood and adolescent obesity within the past 3 decades poses a significant challenge for many pediatric clinicians who are charged with treating this condition. The need for comprehensive, research-based pediatric obesity treatment programs are essential in addressing this problem and preventing the transition of obesity and its many co-morbidities into adulthood. This paper will identify dietary, physical activity, and behavioral approaches to lifestyle change and describe how they are incorporated as part of multidisciplinary treatment interventions in youth. Specific tailoring of treatment programs to address age and varying degrees of overweight and obesity will also be presented along with recommendations for future research. PMID:19573757

Autogenous bone grafts in the esthetic zone: optimizing the procedure using piezosurgery.

PubMed

Majewski, Piotr

2012-12-01

Soft and hard tissue defects pose a therapeutic challenge in modern implant dentistry. There are a multitude of surgical techniques available, and it is necessary to match the problem with the solution. This report describes the reconstruction of the alveolar ridge in the esthetic zone with the help of autogenous bone blocks harvested from the chin that were shaped to fit and stabilized at the recipient site. The procedures were performed using Piezosurgery, which made it possible to introduce surgical modifications and had a significant impact on the accuracy of the procedure. An observation period of 2 to 7 years showed positive stable results for treatment in terms of function and esthetics.

Global issues in environmental medicine.

PubMed

Goldstein, B D

1993-03-01

This overview will discuss a number of the issues posed by the challenge of international environmental health. The reasons that environmental problems occurring elsewhere in the world are of importance to occupational and environmental physicians in North America include the interconnectedness of the biosphere of our planet so that environmental alterations in one part of the globe can have an adverse outcome on our health and well-being; the often high levels of pollution and environmental degradation elsewhere provide an opportunity to determine and predict adverse consequences of environmental agents pertinent to protecting our own health; and, most importantly, our own ability to provide assistance in helping economic development occur in a setting of low risk of environmental pollution.

Space Shuttle Star Tracker Challenges

NASA Technical Reports Server (NTRS)

Herrera, Linda M.

2010-01-01

The space shuttle fleet of avionics was originally designed in the 1970's. Many of the subsystems have been upgraded and replaced, however some original hardware continues to fly. Not only fly, but has proven to be the best design available to perform its designated task. The shuttle star tracker system is currently flying as a mixture of old and new designs, each with a unique purpose to fill for the mission. Orbiter missions have tackled many varied missions in space over the years. As the orbiters began flying to the International Space Station (ISS), new challenges were discovered and overcome as new trusses and modules were added. For the star tracker subsystem, the growing ISS posed an unusual problem, bright light. With two star trackers on board, the 1970's vintage image dissector tube (IDT) star trackers track the ISS, while the new solid state design is used for dim star tracking. This presentation focuses on the challenges and solutions used to ensure star trackers can complete the shuttle missions successfully. Topics include KSC team and industry partner methods used to correct pressurized case failures and track system performance.

Dense Nonaqueous Phase Liquids at Former Manufactured Gas Plants: Challenges to Modeling and Remediation

PubMed Central

Birak, P.S.; Miller, C.T.

2008-01-01

The remediation of dense non-aqueous phase liquids (DNAPLs) in porous media continues to be one of the most challenging problems facing environmental scientists and engineers. Of all the environmentally relevant DNAPLs, tars in the subsurface at former manufactured gas plants (FMGP’s) pose one of the biggest challenges due to their complex chemical composition and tendency to alter wettability. To further our understanding of these complex materials, we consulted historic documentation to evaluate the impact of gas manufacturing on the composition and physicochemical nature of the resulting tars. In the recent literature, most work to date has been focused in a relatively narrow portion of the expected range of tar materials, which has yielded a bias toward samples of relatively low viscosity and density. In this work, we consider the dissolution and movement of tars in the subsurface, models used to predict these phenomena, and approaches used for remediation. We also explore the open issues and detail important gaps in our fundamental understanding of these extraordinarily complex systems that must be resolved to reach a mature level of understanding. PMID:19176266

Kinetic bottlenecks to chemical exchange rates for deep-sea animals II: Carbon dioxide

NASA Astrophysics Data System (ADS)

Hofmann, A. F.; Peltzer, E. T.; Brewer, P. G.

2012-11-01

Increased ocean acidification from fossil fuel CO2 invasion, from temperature-driven changes in respiration, and from possible leakage from sub-seabed geologic CO2 disposal has aroused concern over the impacts of elevated CO2 concentrations on marine life. Discussion of these impacts has so far focused only on changes in the oceanic bulk fluid properties (ΔpH, Δ[∑CO2] etc.) as the critical variable and with a major focus on carbonate shell dissolution. Here we describe the rate problem for animals that must export CO2 at about the same rate at which O2 is consumed. We analyze the basic properties controlling CO2 export within the diffusive boundary layer around marine animals in an ocean changing in temperature (T) and CO2 concentration in order to compare the challenges posed by O2 uptake under stress with the equivalent problem of CO2 expulsion. The problem is more complex than that for a non-reactive gas since, as with gas exchange of CO2 at the air-sea interface, the influence of the ensemble of reactions within the CO2-HCO3--CO32- acid-base system needs to be considered. These reactions significantly facilitate CO2 efflux compared to O2 intake at equal temperature, pressure and flow rate under typical oceanic concentrations.The effect of these reactions can be described by an enhancement factor. For organisms, this means mechanically increasing flow over their surface to thin the boundary layer as is required to alleviate O2 stress seems not necessary to facilitate CO2 efflux. Nevertheless the elevated pCO2 cost most likely is non-zero. Regionally as with O2 the combination of T, P, and pH/pCO2 creates a zone of maximum CO2 stress at around 1000 m depth. But the net result is that, for the problem of gas exchange with the bulk ocean, the combination of an increasing T combined with declining O2 poses a greater challenge to marine life than does increasing CO2. The relationships developed here allow a more accurate prediction of the impacts on marine life from the combined effects of changing T, O2, and CO2 than can be estimated from single variable studies.

The Profile of Creativity and Proposing Statistical Problem Quality Level Reviewed From Cognitive Style

NASA Astrophysics Data System (ADS)

Awi; Ahmar, A. S.; Rahman, A.; Minggi, I.; Mulbar, U.; Asdar; Ruslan; Upu, H.; Alimuddin; Hamda; Rosidah; Sutamrin; Tiro, M. A.; Rusli

2018-01-01

This research aims to reveal the profile about the level of creativity and the ability to propose statistical problem of students at Mathematics Education 2014 Batch in the State University of Makassar in terms of their cognitive style. This research uses explorative qualitative method by giving meta-cognitive scaffolding at the time of research. The hypothesis of research is that students who have field independent (FI) cognitive style in statistics problem posing from the provided information already able to propose the statistical problem that can be solved and create new data and the problem is already been included as a high quality statistical problem, while students who have dependent cognitive field (FD) commonly are still limited in statistics problem posing that can be finished and do not load new data and the problem is included as medium quality statistical problem.

Business Ethics 101 for the biotech industry.

PubMed

MacDonald, Chris

2004-01-01

Biotechnology companies face ethical challenges of two distinct types: bioethical challenges faced on account of the nature of work in the life sciences, and corporate ethical challenges on account of their nature as commercial entities. The latter set of challenges has received almost no attention at all in the academic literature or media. This paper begins to remedy that lacuna, examining ethical issues that arise specifically on account of the status of biotech companies as commercial entities. The focus here is on three representative issues: product safety, corporate social responsibility, and corporate governance. It is argued that each of these issues poses particular ethical challenges for companies in the biotech sector. In the area of product safety, it is noted that biotech companies face particular challenges in determining what counts as a "safe" product, given the contentious nature of what might count as a "harm" in the biotech field. In the area of corporate social responsibility, the adoption of a "stakeholder approach" and an attempt to manage the social consequences of products pose special challenges for biotech companies. This is due to the enormous range of groups and individuals claiming to have a stake in the doings of such companies, and the trenchant controversies over just what the social consequences of various biotechnologies might be. In the area of corporate governance, biotech companies need to seek out and follow best practices regarding the ways in which information, authority, and influence flow between a company's shareholders, managers, and Board of Directors, if they are to avoid duplicating the ethical and financial scandal that brought down ImClone. An important meta-issue, here--one that renders each of these corporate ethical challenges more vexing--is the difficulty of finding the appropriate benchmarks for ethical corporate behavior in a field as controversial, and as rapidly evolving, as biotechnology. Three programmatic suggestions can be made: Firstly, scholars and others interested in the ethical performance of the biotech sector must seek out and build opportunities for richer interdisciplinary collaboration. Secondly, companies within the biotech sector must seek out expertise and build capacity and competency in dealing with the corporate ethical issues that arise in their sector. Finally, companies in the biotech sector should explore the opportunities for collective problem solving afforded by the existence of local, national, and international industry associations such as the Biotechnology Industry Organization, BIOTECanada, and EuropaBio.

Type 1 diabetes: Awareness, management and challenges: Current scenario in India

PubMed Central

Kumar, K.M. Prasanna; Saboo, Banshi; Rao, P.V.; Sarda, Archana; Viswanathan, Vijay; Kalra, Sanjay; Sethi, Bipin; Shah, Nalini; Srikanta, S.S.; Jain, Sunil M; Raghupathy, P.; Shukla, Rishi; Jhingan, Ashok; Chowdhury, Subhankar; Jabbar, P.K.; Kanungo, Alok; Joshi, Rajesh; Kumar, Surendra; Tandon, Nikhil; Khadilkar, Vaman; Chadha, Manoj

2015-01-01

Type 1 diabetes mellitus (T1DM) has a wide presence in children and has a high mortality rates. The disease, if left unmanaged, poses various challenges to the patient and healthcare providers, including development of diabetic complications and thus decreasing the life expectancy of the affected child. The challenges of T1DM include awareness of the disease that is very poor among the general public and also in parents of T1DM children along with the health care professionals. The challenge of lack of awareness of T1DM can be met by increasing public awareness programs, conducting workshops for diabetes educators regarding T1DM in children, newsletters, CMEs, online courses, and by structured teaching modules for diabetes educators. Diagnosis of T1DM was a challenge a few decades ago but the situation has improved today with diagnostic tests and facilities, made available even in villages. Investigation facilities and infrastructure, however, are very poor at the primary care level, especially in rural areas. Insulin availability, acceptability, and affordability are also major problems, compounded by the various types of insulin that are available in the market with a varied price range. But effective use of insulin remains a matter of utmost importance. PMID:25941655

Incorporating structure from motion uncertainty into image-based pose estimation

NASA Astrophysics Data System (ADS)

Ludington, Ben T.; Brown, Andrew P.; Sheffler, Michael J.; Taylor, Clark N.; Berardi, Stephen

2015-05-01

A method for generating and utilizing structure from motion (SfM) uncertainty estimates within image-based pose estimation is presented. The method is applied to a class of problems in which SfM algorithms are utilized to form a geo-registered reference model of a particular ground area using imagery gathered during flight by a small unmanned aircraft. The model is then used to form camera pose estimates in near real-time from imagery gathered later. The resulting pose estimates can be utilized by any of the other onboard systems (e.g. as a replacement for GPS data) or downstream exploitation systems, e.g., image-based object trackers. However, many of the consumers of pose estimates require an assessment of the pose accuracy. The method for generating the accuracy assessment is presented. First, the uncertainty in the reference model is estimated. Bundle Adjustment (BA) is utilized for model generation. While the high-level approach for generating a covariance matrix of the BA parameters is straightforward, typical computing hardware is not able to support the required operations due to the scale of the optimization problem within BA. Therefore, a series of sparse matrix operations is utilized to form an exact covariance matrix for only the parameters that are needed at a particular moment. Once the uncertainty in the model has been determined, it is used to augment Perspective-n-Point pose estimation algorithms to improve the pose accuracy and to estimate the resulting pose uncertainty. The implementation of the described method is presented along with results including results gathered from flight test data.

Intercollegiate Athletics Today and Tomorrow: The President's Challenge

ERIC Educational Resources Information Center

Hanford, George H.

1977-01-01

Colleges and university presidents must come to terms with the challenges posed by intercollegiate athletics. The author offers concrete ideas and suggestions aimed at breaking through the confusion surrounding intercollegiate athletics. (Editor/LBH)

Strategies to improve learning of all students in a class

NASA Astrophysics Data System (ADS)

Suraishkumar, G. K.

2018-05-01

The statistical distribution of the student learning abilities in a typical undergraduate engineering class poses a significant challenge to simultaneously improve the learning of all the students in the class. With traditional instruction styles, the students with significantly high learning abilities are not satisfied due to a feeling of unfulfilled potential, and the students with significantly low learning abilities feel lost. To address the challenge in an undergraduate core/required course on 'transport phenomena in biological systems', a combination of learning strategies such as active learning including co-operative group learning, challenge exercises, and others were employed in a pro-advising context. The short-term and long-term impacts were evaluated through student course performances and input, respectively. The results show that it is possible to effectively address the challenge posed by the distribution of student learning abilities in a class.

Contrasting Perspectives Of Junior versus Senior NASA ISS Flight Controllers On Leadership And Cultural Issues

NASA Technical Reports Server (NTRS)

Clement, James L.; Boyd, J. E.; Saylor, S.; Kanas, N.

2007-01-01

NASA flight controllers have always worked in a very demanding environment, but the International Space Station (ISS) poses even more challenges than prior missions. A recent NASA/Ames survey by Parke and Orasanu of NASA/Johnson flight controllers uncovered concerns about communications problems between American personnel and their international counterparts. To better understand these problems, we interviewed 14 senior and 12 junior ISS flight controllers at NASA/Johnson about leadership and cultural challenges they face and strategies for addressing these challenges. The qualitative interview data were coded and tabulated. Here we present quantitative analyses testing for differences between junior and senior controllers. Based on nonparametric statistical tests comparing responses across groups, the senior controllers were significantly more aware of the impact of working in dispersed teams, the context of constant change, and the upcoming multilateral challenges, while junior controllers were more aware of language and cultural issues. We consider our findings in light of other studies of controllers and other known differences between senior and junior controllers. For example, the fact that senior controllers had their formative early experience controlling pre-ISS short-duration Shuttle missions seems to have both positive and negative aspects, which are supported by our data. Our findings may also reflect gender differences, but we cannot unconfound this effect in our data because all the senior respondents were males. Many of the junior-senior differences are not only due to elapsed time on the job, but also due to a cohort effect. The findings of this study should be used for training curricula tailored differently for junior and senior controllers.

D3R Grand Challenge 2: blind prediction of protein-ligand poses, affinity rankings, and relative binding free energies

NASA Astrophysics Data System (ADS)

Gaieb, Zied; Liu, Shuai; Gathiaka, Symon; Chiu, Michael; Yang, Huanwang; Shao, Chenghua; Feher, Victoria A.; Walters, W. Patrick; Kuhn, Bernd; Rudolph, Markus G.; Burley, Stephen K.; Gilson, Michael K.; Amaro, Rommie E.

2018-01-01

The Drug Design Data Resource (D3R) ran Grand Challenge 2 (GC2) from September 2016 through February 2017. This challenge was based on a dataset of structures and affinities for the nuclear receptor farnesoid X receptor (FXR), contributed by F. Hoffmann-La Roche. The dataset contained 102 IC50 values, spanning six orders of magnitude, and 36 high-resolution co-crystal structures with representatives of four major ligand classes. Strong global participation was evident, with 49 participants submitting 262 prediction submission packages in total. Procedurally, GC2 mimicked Grand Challenge 2015 (GC2015), with a Stage 1 subchallenge testing ligand pose prediction methods and ranking and scoring methods, and a Stage 2 subchallenge testing only ligand ranking and scoring methods after the release of all blinded co-crystal structures. Two smaller curated sets of 18 and 15 ligands were developed to test alchemical free energy methods. This overview summarizes all aspects of GC2, including the dataset details, challenge procedures, and participant results. We also consider implications for progress in the field, while highlighting methodological areas that merit continued development. Similar to GC2015, the outcome of GC2 underscores the pressing need for methods development in pose prediction, particularly for ligand scaffolds not currently represented in the Protein Data Bank (http://www.pdb.org), and in affinity ranking and scoring of bound ligands.

Sensitivity computation of the ell1 minimization problem and its application to dictionary design of ill-posed problems

NASA Astrophysics Data System (ADS)

Horesh, L.; Haber, E.

2009-09-01

The ell1 minimization problem has been studied extensively in the past few years. Recently, there has been a growing interest in its application for inverse problems. Most studies have concentrated in devising ways for sparse representation of a solution using a given prototype dictionary. Very few studies have addressed the more challenging problem of optimal dictionary construction, and even these were primarily devoted to the simplistic sparse coding application. In this paper, sensitivity analysis of the inverse solution with respect to the dictionary is presented. This analysis reveals some of the salient features and intrinsic difficulties which are associated with the dictionary design problem. Equipped with these insights, we propose an optimization strategy that alleviates these hurdles while utilizing the derived sensitivity relations for the design of a locally optimal dictionary. Our optimality criterion is based on local minimization of the Bayesian risk, given a set of training models. We present a mathematical formulation and an algorithmic framework to achieve this goal. The proposed framework offers the design of dictionaries for inverse problems that incorporate non-trivial, non-injective observation operators, where the data and the recovered parameters may reside in different spaces. We test our algorithm and show that it yields improved dictionaries for a diverse set of inverse problems in geophysics and medical imaging.

Young men exempted from compulsory military or civil service in Finland--a group of men in need of psychosocial support?

PubMed

Appelqvist-Schmidlechner, K; Upanne, M; Henriksson, M; Parkkola, K; Stengård, E

2010-03-01

The aim of this study was to find out whether young men exempted from compulsory military or civil service constitute a group of young men in need of psychosocial support from the social and health services. The study involved a total of 356 men exempted from military or civil service and 440 young men conscripted into service. The research data were collected using questionnaires and register data. Men exempted from military or civil service differed from conscripts in terms of psychosocial well-being. Compared with conscripts, they had already been in a more disadvantaged position with regard to their childhood living conditions. As young adults, they had met with a greater number of mental and social problems than conscripts: alcohol-related problems, unemployment, financial problems, homelessness, lack of social support and psychological distress. Young men exempted from service typically suffered from an accumulation of problems. Diverse problems were common particularly among men who had interrupted their service. There was a moderate correlation between current and childhood adversities. Men exempted from military or civil service comprise a group with a wide range of psychosocial problems and are a target group for supportive interventions. Special attention should be paid to the prevention of problems and promotion of well-being of men who interrupt their service. The accumulation of problems poses a challenge for the development of such interventions.

Irritable bowel syndrome in children: Current knowledge, challenges and opportunities

PubMed Central

Devanarayana, Niranga Manjuri; Rajindrajith, Shaman

2018-01-01

Irritable bowel syndrome (IBS) is a common and troublesome disorder in children with an increasing prevalence noted during the past two decades. It has a significant effect on the lives of affected children and their families and poses a significant burden on healthcare systems. Standard symptom-based criteria for diagnosis of pediatric IBS have changed several times during the past two decades and there are some differences in interpreting symptoms between different cultures. This has posed a problem when using them to diagnose IBS in clinical practice. A number of potential patho-physiological mechanisms have been described, but so far the exact underlying etiology of IBS is unclear. A few potential therapeutic modalities have been tested in children and only a small number of them have shown some benefit. In addition, most of the described patho-physiological mechanisms and treatment options are based on adult studies. These have surfaced as challenges when dealing with pediatric IBS and they need to be overcome for effective management of children with IBS. Recently suggested top-down and bottom-up models help integrating reported patho-physiological mechanisms and will provide an opportunity for better understanding of the diseases process. Treatment trials targeting single treatment modalities are unlikely to have clinically meaningful therapeutic effects on IBS with multiple integrating patho-physiologies. Trials focusing on multiple combined pharmacological and non-pharmacological therapies are likely to yield more benefit. In addition to treatment, in the future, attention should be paid for possible prevention strategies for IBS. PMID:29881232

Plasticity of the Binding Site of Renin: Optimized Selection of Protein Structures for Ensemble Docking.

PubMed

Strecker, Claas; Meyer, Bernd

2018-05-29

Protein flexibility poses a major challenge to docking of potential ligands in that the binding site can adopt different shapes. Docking algorithms usually keep the protein rigid and only allow the ligand to be treated as flexible. However, a wrong assessment of the shape of the binding pocket can prevent a ligand from adapting a correct pose. Ensemble docking is a simple yet promising method to solve this problem: Ligands are docked into multiple structures, and the results are subsequently merged. Selection of protein structures is a significant factor for this approach. In this work we perform a comprehensive and comparative study evaluating the impact of structure selection on ensemble docking. We perform ensemble docking with several crystal structures and with structures derived from molecular dynamics simulations of renin, an attractive target for antihypertensive drugs. Here, 500 ns of MD simulations revealed binding site shapes not found in any available crystal structure. We evaluate the importance of structure selection for ensemble docking by comparing binding pose prediction, ability to rank actives above nonactives (screening utility), and scoring accuracy. As a result, for ensemble definition k-means clustering appears to be better suited than hierarchical clustering with average linkage. The best performing ensemble consists of four crystal structures and is able to reproduce the native ligand poses better than any individual crystal structure. Moreover this ensemble outperforms 88% of all individual crystal structures in terms of screening utility as well as scoring accuracy. Similarly, ensembles of MD-derived structures perform on average better than 75% of any individual crystal structure in terms of scoring accuracy at all inspected ensembles sizes.

Manufacturing and Security Challenges in 3D Printing

NASA Astrophysics Data System (ADS)

Zeltmann, Steven Eric; Gupta, Nikhil; Tsoutsos, Nektarios Georgios; Maniatakos, Michail; Rajendran, Jeyavijayan; Karri, Ramesh

2016-07-01

As the manufacturing time, quality, and cost associated with additive manufacturing (AM) continue to improve, more and more businesses and consumers are adopting this technology. Some of the key benefits of AM include customizing products, localizing production and reducing logistics. Due to these and numerous other benefits, AM is enabling a globally distributed manufacturing process and supply chain spanning multiple parties, and hence raises concerns about the reliability of the manufactured product. In this work, we first present a brief overview of the potential risks that exist in the cyber-physical environment of additive manufacturing. We then evaluate the risks posed by two different classes of modifications to the AM process which are representative of the challenges that are unique to AM. The risks posed are examined through mechanical testing of objects with altered printing orientation and fine internal defects. Finite element analysis and ultrasonic inspection are also used to demonstrate the potential for decreased performance and for evading detection. The results highlight several scenarios, intentional or unintentional, that can affect the product quality and pose security challenges for the additive manufacturing supply chain.

Better together? a naturalistic qualitative study of inter-professional working in collaborative care for co-morbid depression and physical health problems.

PubMed

Knowles, Sarah E; Chew-Graham, Carolyn; Coupe, Nia; Adeyemi, Isabel; Keyworth, Chris; Thampy, Harish; Coventry, Peter A

2013-09-20

Mental-physical multi-morbidities pose challenges for primary care services that traditionally focus on single diseases. Collaborative care models encourage inter-professional working to deliver better care for patients with multiple chronic conditions, such as depression and long-term physical health problems. Successive trials from the United States have shown that collaborative care effectively improves depression outcomes, even in people with long-term conditions (LTCs), but little is known about how to implement collaborative care in the United Kingdom. The aim of the study was to explore the extent to which collaborative care was implemented in a naturalistic National Health Service setting. A naturalistic pilot study of collaborative care was undertaken in North West England. Primary care mental health professionals from IAPT (Increasing Access to Psychological Therapies) services and general practice nurses were trained to collaboratively identify and manage patients with co-morbid depression and long-term conditions. Qualitative interviews were performed with health professionals at the beginning and end of the pilot phase. Normalization Process Theory guided analysis. Health professionals adopted limited elements of the collaborative care model in practice. Although benefits of co-location in primary care practices were reported, including reduced stigma of accessing mental health treatment and greater ease of disposal for identified patients, existing norms around the division of mental and physical health work in primary care were maintained, limiting integration of the mental health practitioners into the practice setting. Neither the mental health practitioners nor the practice nurses perceived benefits to joint management of patients. Established divisions between mental and physical health may pose particular challenges for multi-morbidity service delivery models such as collaborative care. Future work should explore patient perspectives about whether greater inter-professional working enhances experiences of care. The study demonstrates that research into implementation of novel treatments must consider how the introduction of innovation can be balanced with the need for integration into existing practice.

Better together? a naturalistic qualitative study of inter-professional working in collaborative care for co-morbid depression and physical health problems

PubMed Central

2013-01-01

Background Mental-physical multi-morbidities pose challenges for primary care services that traditionally focus on single diseases. Collaborative care models encourage inter-professional working to deliver better care for patients with multiple chronic conditions, such as depression and long-term physical health problems. Successive trials from the United States have shown that collaborative care effectively improves depression outcomes, even in people with long-term conditions (LTCs), but little is known about how to implement collaborative care in the United Kingdom. The aim of the study was to explore the extent to which collaborative care was implemented in a naturalistic National Health Service setting. Methods A naturalistic pilot study of collaborative care was undertaken in North West England. Primary care mental health professionals from IAPT (Increasing Access to Psychological Therapies) services and general practice nurses were trained to collaboratively identify and manage patients with co-morbid depression and long-term conditions. Qualitative interviews were performed with health professionals at the beginning and end of the pilot phase. Normalization Process Theory guided analysis. Results Health professionals adopted limited elements of the collaborative care model in practice. Although benefits of co-location in primary care practices were reported, including reduced stigma of accessing mental health treatment and greater ease of disposal for identified patients, existing norms around the division of mental and physical health work in primary care were maintained, limiting integration of the mental health practitioners into the practice setting. Neither the mental health practitioners nor the practice nurses perceived benefits to joint management of patients. Conclusions Established divisions between mental and physical health may pose particular challenges for multi-morbidity service delivery models such as collaborative care. Future work should explore patient perspectives about whether greater inter-professional working enhances experiences of care. The study demonstrates that research into implementation of novel treatments must consider how the introduction of innovation can be balanced with the need for integration into existing practice. PMID:24053257

Face pose tracking using the four-point algorithm

NASA Astrophysics Data System (ADS)

Fung, Ho Yin; Wong, Kin Hong; Yu, Ying Kin; Tsui, Kwan Pang; Kam, Ho Chuen

2017-06-01

In this paper, we have developed an algorithm to track the pose of a human face robustly and efficiently. Face pose estimation is very useful in many applications such as building virtual reality systems and creating an alternative input method for the disabled. Firstly, we have modified a face detection toolbox called DLib for the detection of a face in front of a camera. The detected face features are passed to a pose estimation method, known as the four-point algorithm, for pose computation. The theory applied and the technical problems encountered during system development are discussed in the paper. It is demonstrated that the system is able to track the pose of a face in real time using a consumer grade laptop computer.

What is the danger of the anomaly zone for empirical phylogenetics?

PubMed

Huang, Huateng; Knowles, L Lacey

2009-10-01

The increasing number of observations of gene trees with discordant topologies in phylogenetic studies has raised awareness about the problems of incongruence between species trees and gene trees. Moreover, theoretical treatments focusing on the impact of coalescent variance on phylogenetic study have also identified situations where the most probable gene trees are ones that do not match the underlying species tree (i.e., anomalous gene trees [AGTs]). However, although the theoretical proof of the existence of AGTs is alarming, the actual risk that AGTs pose to empirical phylogenetic study is far from clear. Establishing the conditions (i.e., the branch lengths in a species tree) for which AGTs are possible does not address the critical issue of how prevalent they might be. Furthermore, theoretical characterization of the species trees for which AGTs may pose a problem (i.e., the anomaly zone or the species histories for which AGTs are theoretically possible) is based on consideration of just one source of variance that contributes to species tree and gene tree discord-gene lineage coalescence. Yet, empirical data contain another important stochastic component-mutational variance. Estimated gene trees will differ from the underlying gene trees (i.e., the actual genealogy) because of the random process of mutation. Here, we take a simulation approach to investigate the prevalence of AGTs, among estimated gene trees, thereby characterizing the boundaries of the anomaly zone taking into account both coalescent and mutational variances. We also determine the frequency of realized AGTs, which is critical to putting the theoretical work on AGTs into a realistic biological context. Two salient results emerge from this investigation. First, our results show that mutational variance can indeed expand the parameter space (i.e., the relative branch lengths in a species tree) where AGTs might be observed in empirical data. By exploring the underlying cause for the expanded anomaly zone, we identify aspects of empirical data relevant to avoiding the problems that AGTs pose for species tree inference from multilocus data. Second, for the empirical species histories where AGTs are possible, unresolved trees-not AGTs-predominate the pool of estimated gene trees. This result suggests that the risk of AGTs, while they exist in theory, may rarely be realized in practice. By considering the biological realities of both mutational and coalescent variances, the study has refined, and redefined, what the actual challenges are for empirical phylogenetic study of recently diverged taxa that have speciated rapidly-AGTs themselves are unlikely to pose a significant danger to empirical phylogenetic study.

Phase unwrapping with graph cuts optimization and dual decomposition acceleration for 3D high-resolution MRI data.

PubMed

Dong, Jianwu; Chen, Feng; Zhou, Dong; Liu, Tian; Yu, Zhaofei; Wang, Yi

2017-03-01

Existence of low SNR regions and rapid-phase variations pose challenges to spatial phase unwrapping algorithms. Global optimization-based phase unwrapping methods are widely used, but are significantly slower than greedy methods. In this paper, dual decomposition acceleration is introduced to speed up a three-dimensional graph cut-based phase unwrapping algorithm. The phase unwrapping problem is formulated as a global discrete energy minimization problem, whereas the technique of dual decomposition is used to increase the computational efficiency by splitting the full problem into overlapping subproblems and enforcing the congruence of overlapping variables. Using three dimensional (3D) multiecho gradient echo images from an agarose phantom and five brain hemorrhage patients, we compared this proposed method with an unaccelerated graph cut-based method. Experimental results show up to 18-fold acceleration in computation time. Dual decomposition significantly improves the computational efficiency of 3D graph cut-based phase unwrapping algorithms. Magn Reson Med 77:1353-1358, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Heart Failure Epidemiology: European Perspective

PubMed Central

Guha, K; McDonagh, T

2013-01-01

Heart failure poses an increasing problem for global healthcare systems. The epidemiological data which has been accrued over the last thirty years has predominantly been accumulated from experience within North America and Europe. Initial large cohort, prospective longitudinal studies produced the first publications; however latterly the focus has shifted onto epidemiological data governing hospitalisation and mortality. The emphasis behind this shift has been the resource implications with regards to repetitive, costly and prolonged hospitalisation. The European experience in heart failure, though similar to North America has recently demonstrated differences in hospitalisation which may underlie the differences between healthcare system configuration. Heart failure however remains an increasing global problem and the endpoint of a variety of cardiovascular diseases. Allied with the fact of increasingly elderly populations and prior data demonstrating a steep rise in prevalent cases within more elderly populations, it is likely that the increasing burden of disease will continue to pose challenges for modern healthcare. Despite the predicted increase in the number of patients affected by heart failure, over the last thirty years, a clear management algorithm has evolved for the use of pharmacotherapies (neuro-hormonal antagonists), device based therapies (Implantable Cardioverting Defibrillator (ICD) and Cardiac Resynchronisation Therapy (CRT)) and mechanical therapies including left ventricular assist devices and cardiac transplantation. Though the management of such patients has been clearly delineated in national and international guidelines, the underuse of all available and appropriate therapies remains a significant problem. When comparing various epidemiological studies from different settings and timepoints, it should be remembered that rates of prevalence and incidence may vary depending upon the definition used, methods of accumulating information (with the possibility of bias) and the chosen cut point of defining left ventricular systolic dysfunction (LVSD). PMID:23597298

Fitting methods to paradigms: are ergonomics methods fit for systems thinking?

PubMed

Salmon, Paul M; Walker, Guy H; M Read, Gemma J; Goode, Natassia; Stanton, Neville A

2017-02-01

The issues being tackled within ergonomics problem spaces are shifting. Although existing paradigms appear relevant for modern day systems, it is worth questioning whether our methods are. This paper asks whether the complexities of systems thinking, a currently ubiquitous ergonomics paradigm, are outpacing the capabilities of our methodological toolkit. This is achieved through examining the contemporary ergonomics problem space and the extent to which ergonomics methods can meet the challenges posed. Specifically, five key areas within the ergonomics paradigm of systems thinking are focused on: normal performance as a cause of accidents, accident prediction, system migration, systems concepts and ergonomics in design. The methods available for pursuing each line of inquiry are discussed, along with their ability to respond to key requirements. In doing so, a series of new methodological requirements and capabilities are identified. It is argued that further methodological development is required to provide researchers and practitioners with appropriate tools to explore both contemporary and future problems. Practitioner Summary: Ergonomics methods are the cornerstone of our discipline. This paper examines whether our current methodological toolkit is fit for purpose given the changing nature of ergonomics problems. The findings provide key research and practice requirements for methodological development.

Student Media Production to Meet Challenges in Climate Change Science Education

ERIC Educational Resources Information Center

Rooney-Varga, Juliette N.; Brisk, Angelica Allende; Adams, Elizabeth; Shuldman, Elizabeth; Rath, Kenneth

2014-01-01

While the need for effective climate change education is growing, this area of geoscience also poses unique educational challenges. These challenges include the politicization of climate change, the psychological and affective responses it elicits, and common misconceptions, which can all create barriers to learning. Here, we present an…

Transforming Teaching Challenges into Learning Opportunities: Interdisciplinary Reflective Collaboration

ERIC Educational Resources Information Center

Callaghan, Ronel

2015-01-01

Teaching in higher education poses unique sets of challenges, especially for academics in the engineering, built sciences and information science education disciplines. This article focuses on how reflective collaboration can support academics in their quest to find unique solutions to challenges in different academic contexts. A reflective…

Space-Time Conservation Element and Solution Element Method Being Developed

NASA Technical Reports Server (NTRS)

Chang, Sin-Chung; Himansu, Ananda; Jorgenson, Philip C. E.; Loh, Ching-Yuen; Wang, Xiao-Yen; Yu, Sheng-Tao

1999-01-01

The engineering research and design requirements of today pose great computer-simulation challenges to engineers and scientists who are called on to analyze phenomena in continuum mechanics. The future will bring even more daunting challenges, when increasingly complex phenomena must be analyzed with increased accuracy. Traditionally used numerical simulation methods have evolved to their present state by repeated incremental extensions to broaden their scope. They are reaching the limits of their applicability and will need to be radically revised, at the very least, to meet future simulation challenges. At the NASA Lewis Research Center, researchers have been developing a new numerical framework for solving conservation laws in continuum mechanics, namely, the Space-Time Conservation Element and Solution Element Method, or the CE/SE method. This method has been built from fundamentals and is not a modification of any previously existing method. It has been designed with generality, simplicity, robustness, and accuracy as cornerstones. The CE/SE method has thus far been applied in the fields of computational fluid dynamics, computational aeroacoustics, and computational electromagnetics. Computer programs based on the CE/SE method have been developed for calculating flows in one, two, and three spatial dimensions. Results have been obtained for numerous problems and phenomena, including various shock-tube problems, ZND detonation waves, an implosion and explosion problem, shocks over a forward-facing step, a blast wave discharging from a nozzle, various acoustic waves, and shock/acoustic-wave interactions. The method can clearly resolve shock/acoustic-wave interactions, wherein the difference of the magnitude between the acoustic wave and shock could be up to six orders. In two-dimensional flows, the reflected shock is as crisp as the leading shock. CE/SE schemes are currently being used for advanced applications to jet and fan noise prediction and to chemically reacting flows.

Docking pose selection by interaction pattern graph similarity: application to the D3R grand challenge 2015.

PubMed

Slynko, Inna; Da Silva, Franck; Bret, Guillaume; Rognan, Didier

2016-09-01

High affinity ligands for a given target tend to share key molecular interactions with important anchoring amino acids and therefore often present quite conserved interaction patterns. This simple concept was formalized in a topological knowledge-based scoring function (GRIM) for selecting the most appropriate docking poses from previously X-rayed interaction patterns. GRIM first converts protein-ligand atomic coordinates (docking poses) into a simple 3D graph describing the corresponding interaction pattern. In a second step, proposed graphs are compared to that found from template structures in the Protein Data Bank. Last, all docking poses are rescored according to an empirical score (GRIMscore) accounting for overlap of maximum common subgraphs. Taking the opportunity of the public D3R Grand Challenge 2015, GRIM was used to rescore docking poses for 36 ligands (6 HSP90α inhibitors, 30 MAP4K4 inhibitors) prior to the release of the corresponding protein-ligand X-ray structures. When applied to the HSP90α dataset, for which many protein-ligand X-ray structures are already available, GRIM provided very high quality solutions (mean rmsd = 1.06 Å, n = 6) as top-ranked poses, and significantly outperformed a state-of-the-art scoring function. In the case of MAP4K4 inhibitors, for which preexisting 3D knowledge is scarce and chemical diversity is much larger, the accuracy of GRIM poses decays (mean rmsd = 3.18 Å, n = 30) although GRIM still outperforms an energy-based scoring function. GRIM rescoring appears to be quite robust with comparison to the other approaches competing for the same challenge (42 submissions for the HSP90 dataset, 27 for the MAP4K4 dataset) as it ranked 3rd and 2nd respectively, for the two investigated datasets. The rescoring method is quite simple to implement, independent on a docking engine, and applicable to any target for which at least one holo X-ray structure is available.

Efficient computation of hashes

NASA Astrophysics Data System (ADS)

Lopes, Raul H. C.; Franqueira, Virginia N. L.; Hobson, Peter R.

2014-06-01

The sequential computation of hashes at the core of many distributed storage systems and found, for example, in grid services can hinder efficiency in service quality and even pose security challenges that can only be addressed by the use of parallel hash tree modes. The main contributions of this paper are, first, the identification of several efficiency and security challenges posed by the use of sequential hash computation based on the Merkle-Damgard engine. In addition, alternatives for the parallel computation of hash trees are discussed, and a prototype for a new parallel implementation of the Keccak function, the SHA-3 winner, is introduced.

Head pose estimation in computer vision: a survey.

PubMed

Murphy-Chutorian, Erik; Trivedi, Mohan Manubhai

2009-04-01

The capacity to estimate the head pose of another person is a common human ability that presents a unique challenge for computer vision systems. Compared to face detection and recognition, which have been the primary foci of face-related vision research, identity-invariant head pose estimation has fewer rigorously evaluated systems or generic solutions. In this paper, we discuss the inherent difficulties in head pose estimation and present an organized survey describing the evolution of the field. Our discussion focuses on the advantages and disadvantages of each approach and spans 90 of the most innovative and characteristic papers that have been published on this topic. We compare these systems by focusing on their ability to estimate coarse and fine head pose, highlighting approaches that are well suited for unconstrained environments.

Development of vaccines for bio-warfare agents.

PubMed

Rosenthal, S R; Clifford, J C M

2002-01-01

There is a recognized need for the development of new vaccines (as well as other biologicals and drugs) to counteract the effects of a potential bio-terrorist or bio-warfare event in the U.S. domestic population and military forces. Regulation of products to protect against potential bio-warfare agents poses unique challenges since the usual measures of efficacy that require exposure to natural disease may not currently be possible, for epidemiological and ethical reasons. To help to address this issue, the FDA has published and requested comments on a proposed animal rule intended to address certain efficacy issues for new agents for use against lethal or permanently disabling toxic substances. Recent product development activity has focused on Bacillus anthracis (anthrax) and variola major (smallpox), agents that are regarded as highest priority in posing a risk to national security. FDA resources exist to assist vaccine developers with regard to the novel challenges posed in the dinical development of these products.

PTSD-8: A Short PTSD Inventory

PubMed Central

Hansen, Maj; Andersen, Tonny Elmose; Armour, Cherie; Elklit, Ask; Palic, Sabina; Mackrill, Thomas

2010-01-01

Traumatic events pose great challenges on mental health services in scarcity of specialist trauma clinicians and services. Simple short screening instruments for detecting adverse psychological responses are needed. Several brief screening instruments have been developed. However, some are limited, especially in relation to reflecting the posttraumatic stress disorder (PTSD) diagnosis. Recently, several studies have challenged pre-existing ideas about PTSD’s latent structure. Factor analytic research currently supports two four factor models. One particular model contains a dysphoria factor which has been associated with depression and anxiety. The symptoms in this factor have been hailed as less specific to PTSD. The scope of this article is therefore to present a short screening instrument, based on this research; Posttraumatic Stress Disorder (PTSD) – 8 items. The PTSD-8 is shown to have good psychometric properties in three independent samples of whiplash patients (n=1710), rape victims (n=305), and disaster victims (n=516). Good test-rest reliability is also shown in a pilot study of young adults from families with alcohol problems (n=56). PMID:21253461

PTSD-8: A Short PTSD Inventory.

PubMed

Hansen, Maj; Andersen, Tonny Elmose; Armour, Cherie; Elklit, Ask; Palic, Sabina; Mackrill, Thomas

2010-09-28

Traumatic events pose great challenges on mental health services in scarcity of specialist trauma clinicians and services. Simple short screening instruments for detecting adverse psychological responses are needed. Several brief screening instruments have been developed. However, some are limited, especially in relation to reflecting the posttraumatic stress disorder (PTSD) diagnosis. Recently, several studies have challenged pre-existing ideas about PTSD's latent structure. Factor analytic research currently supports two four factor models. One particular model contains a dysphoria factor which has been associated with depression and anxiety. The symptoms in this factor have been hailed as less specific to PTSD. The scope of this article is therefore to present a short screening instrument, based on this research; Posttraumatic Stress Disorder (PTSD) - 8 items. The PTSD-8 is shown to have good psychometric properties in three independent samples of whiplash patients (n=1710), rape victims (n=305), and disaster victims (n=516). Good test-rest reliability is also shown in a pilot study of young adults from families with alcohol problems (n=56).

Algorithmic aspects for the reconstruction of spatio-spectral data cubes in the perspective of the SKA

NASA Astrophysics Data System (ADS)

Mary, D.; Ferrari, A.; Ferrari, C.; Deguignet, J.; Vannier, M.

2016-12-01

With millions of receivers leading to TerraByte data cubes, the story of the giant SKA telescope is also that of collaborative efforts from radioastronomy, signal processing, optimization and computer sciences. Reconstructing SKA cubes poses two challenges. First, the majority of existing algorithms work in 2D and cannot be directly translated into 3D. Second, the reconstruction implies solving an inverse problem and it is not clear what ultimate limit we can expect on the error of this solution. This study addresses (of course partially) both challenges. We consider an extremely simple data acquisition model, and we focus on strategies making it possible to implement 3D reconstruction algorithms that use state-of-the-art image/spectral regularization. The proposed approach has two main features: (i) reduced memory storage with respect to a previous approach; (ii) efficient parallelization and ventilation of the computational load over the spectral bands. This work will allow to implement and compare various 3D reconstruction approaches in a large scale framework.

Open-access databases as unprecedented resources and drivers of cultural change in fisheries science

DOE Office of Scientific and Technical Information (OSTI.GOV)

McManamay, Ryan A; Utz, Ryan

2014-01-01

Open-access databases with utility in fisheries science have grown exponentially in quantity and scope over the past decade, with profound impacts to our discipline. The management, distillation, and sharing of an exponentially growing stream of open-access data represents several fundamental challenges in fisheries science. Many of the currently available open-access resources may not be universally known among fisheries scientists. We therefore introduce many national- and global-scale open-access databases with applications in fisheries science and provide an example of how they can be harnessed to perform valuable analyses without additional field efforts. We also discuss how the development, maintenance, and utilizationmore » of open-access data are likely to pose technical, financial, and educational challenges to fisheries scientists. Such cultural implications that will coincide with the rapidly increasing availability of free data should compel the American Fisheries Society to actively address these problems now to help ease the forthcoming cultural transition.« less

Rapid Cost Assessment of Space Mission Concepts through Application of Complexity Indices

NASA Technical Reports Server (NTRS)

Peterson, Craig; Cutts, James; Balint, Tibor; Hall, James B.

2008-01-01

In 2005, the Solar System Exploration Strategic Roadmap Conmrittee (chartered by NASA to develop the roadmap for Solar System Exploration Missions for the coming decades) found itself posed with the difficult problem of sorting through several mission concepts and determining their relative costs. While detailed mission studies are the normal approach to costing, neither the budget nor schedule allotted to the conmrittee could support such studies. Members of the Jet Propulsion Laboratory (JPL) supporting the conmrittee were given the challenge of developing a semi-quantitative approach that could provide the relative costs of these missions, without requiring an in depth study of the missions. In response to this challenge, a rapid cost assessment methodology based on a set of mission cost/complexity indexes was developed. This methodology also underwent two separate validations, one comparing its results when applied to historical missions, and another comparing its estimates against those of veteran space mission managers. Remarkably good agreement was achieved, suggesting that this approach provides an effective early indication of space mission costs.

From Here to Autonomy.

PubMed

Endsley, Mica R

2017-02-01

As autonomous and semiautonomous systems are developed for automotive, aviation, cyber, robotics and other applications, the ability of human operators to effectively oversee and interact with them when needed poses a significant challenge. An automation conundrum exists in which as more autonomy is added to a system, and its reliability and robustness increase, the lower the situation awareness of human operators and the less likely that they will be able to take over manual control when needed. The human-autonomy systems oversight model integrates several decades of relevant autonomy research on operator situation awareness, out-of-the-loop performance problems, monitoring, and trust, which are all major challenges underlying the automation conundrum. Key design interventions for improving human performance in interacting with autonomous systems are integrated in the model, including human-automation interface features and central automation interaction paradigms comprising levels of automation, adaptive automation, and granularity of control approaches. Recommendations for the design of human-autonomy interfaces are presented and directions for future research discussed.

Design of a spanloader cargo aircraft

NASA Technical Reports Server (NTRS)

1989-01-01

With a growing demand for fast international freight service, the slow-moving cargo ships currently in use will soon find a substantial portion of their clients looking elsewhere. One candidate for filling this expected gap in the freight market is a span-loading aircraft (or 'flying wing') capable of long-range operation with extremely large payloads. This report summarizes the design features of an aircraft capable of fulfilling a long-haul, high-capacity cargo mission. The spanloader seeks to gain advantage over conventional aircraft by eliminating the aircraft fuselage and thus reducing empty weight. The primary disadvantage of this configuration is that the cargo-containing wing tends to be thick, thus posing a challenge to the airfoil designer. It also suffers from stability and control problems not encountered by conventional aircraft. The result is an interesting, challenging exercise in unconventional design. The report that follows is a student written synopsis of an effort judged to be the best of eight designs developed during the year 1988-1989.

Facilitating student retention in online graduate nursing education programs: a review of the literature.

PubMed

Gazza, Elizabeth A; Hunker, Diane F

2014-07-01

Online education, a form of distance education, provides students with opportunities to engage in lifelong learning without the restrictions of time and space. However, while this approach meets the needs of employed nursing professionals, it poses some challenges for educators. Student retention is one such challenge. Student retention rates serve as measures of program quality and are reported to accrediting bodies. Therefore, it is imperative that administrators and program faculty implement comprehensive programs to ensure student retention. This review of the literature was designed to identify strategies to improve student retention in online graduate nursing education programs. The review includes 23 articles that address models, research, and best practices supported in nursing and higher education. The findings indicate that student retention in online programs is a multidimensional problem requiring a multifaceted approach. Recommendations for facilitating retention in online nursing programs include ensuring social presence and program and course quality, and attentiveness to individual student characteristics. Copyright © 2014 Elsevier Ltd. All rights reserved.