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Sample records for perspectives structural problems

  1. Alternative Perspectives on Risk: Individual Differences in Problem Structuring

    NASA Technical Reports Server (NTRS)

    Orasanu, Judith; Fischer, Ute; Connors, Mary M. (Technical Monitor)

    1997-01-01

    Team decision making involves contributions of multiple players toward a common goal. While much has been written about the importance of developing shared mental models in order for teams to work together effectively, little has been done to determine the value of alternative perspectives on problem solving and decision making. Early studies of expertise contrasted experts with novices and noted that the two groups differ in the way they structure problems and in their selection of information as salient. Little attention has been given to differences among experts who differ in their specializations. A series of experiments was conducted to determine: (1) what dimensions of flight-related problem situations pilots judge to be most important when making flight-relevant decisions; and (2) whether pilots in different crew positions differ in the way they interpret problems relating to flight decisions. A sorting task was used to identify underlying dimensions judged as salient to individual pilots. Captains, first officers, and flight engineers from two major carriers participated in the study. Twenty-two flight scenarios were developed based on ASRS reports. Pilots were required to make judgments about how they would respond in each case and to sort the scenarios on the basis of similarity of decision factors. They were also asked to provide a verbal label that described each of their sorted categories. A second study required a different group of pilots (also captains, first officers and flight engineers) to sort on predetermined bases.

  2. Algorithmic Perspectives on Problem Formulations in MDO

    NASA Technical Reports Server (NTRS)

    Alexandrov, Natalia M.; Lewis, Robert Michael

    2000-01-01

    This work is concerned with an approach to formulating the multidisciplinary optimization (MDO) problem that reflects an algorithmic perspective on MDO problem solution. The algorithmic perspective focuses on formulating the problem in light of the abilities and inabilities of optimization algorithms, so that the resulting nonlinear programming problem can be solved reliably and efficiently by conventional optimization techniques. We propose a modular approach to formulating MDO problems that takes advantage of the problem structure, maximizes the autonomy of implementation, and allows for multiple easily interchangeable problem statements to be used depending on the available resources and the characteristics of the application problem.

  3. Comparing Multiple Solutions in the Structured Problem Solving: Deconstructing Japanese Lessons from Learner's Perspective

    ERIC Educational Resources Information Center

    Hino, Keiko

    2015-01-01

    The purpose of this study is to enhance our understanding of how students listen and attend to multiple solutions proposed by their classmates during the activity of comparison. This study examines ten consecutive lessons in each of the two eighth-grade classrooms in Tokyo that are organized in the style of "structured problem solving".…

  4. Comparing Multiple Solutions in the Structured Problem Solving: Deconstructing Japanese Lessons from Learner's Perspective

    ERIC Educational Resources Information Center

    Hino, Keiko

    2015-01-01

    The purpose of this study is to enhance our understanding of how students listen and attend to multiple solutions proposed by their classmates during the activity of comparison. This study examines ten consecutive lessons in each of the two eighth-grade classrooms in Tokyo that are organized in the style of "structured problem solving".…

  5. Problem-Framing: A perspective on environmental problem-solving

    NASA Astrophysics Data System (ADS)

    Bardwell, Lisa V.

    1991-09-01

    The specter of environmental calamity calls for the best efforts of an involved public. Ironically, the way people understand the issues all too often serves to discourage and frustrate rather than motivate them to action. This article draws from problem-solving perspectives offered by cognitive psychology and conflict management to examine a framework for thinking about environmental problems that promises to help rather than hinder efforts to address them. Problem-framing emphasizes focusing on the problem definition. Since how one defines a problem determines one's understanding of and approach to that problem, being able to redefine or reframe a problem and to explore the “problem space” can help broaden the range of alternatives and solutions examined. Problem-framing incorporates a cognitive perspective on how people respond to information. It explains why an emphasis on problem definition is not part of people's typical approach to problems. It recognizes the importance of structure and of having ways to organize that information on one's problem-solving effort. Finally, problem-framing draws on both cognitive psychology and conflict management for strategies to manage information and to create a problem-solving environment that not only encourages participation but can yield better approaches to our environmental problems.

  6. Structural dynamics problems of future spacecraft systems - New solution methods and perspectives

    NASA Astrophysics Data System (ADS)

    Breitbach, E.; Hueners, H.

    The mechanical and thermal loads imposed on spacecraft and payloads during launch and reentry, the methods used to predict and simulate these loads, and the design implications of typical loading levels are reviewed, with reference to the FRG Planning Framework for High Technology and Space Flight. A typical satellite mission profile is shown; the structural-dynamic qualification process is outlined; system identification methods are described in detail; and the fundamental principles of passive and active vibration control are discussed. Extensive diagrams, drawings, graphs, and photographs are provided.

  7. Perspectives on Problem Solving and Instruction

    ERIC Educational Resources Information Center

    van Merrienboer, Jeroen J. G.

    2013-01-01

    Most educators claim that problem solving is important, but they take very different perspective on it and there is little agreement on how it should be taught. This article aims to sort out the different perspectives and discusses problem solving as a goal, a method, and a skill. As a goal, problem solving should not be limited to well-structured…

  8. [Addiction therapy. Limits, problems, perspectives].

    PubMed

    Kalapos, Miklós Péter

    2014-01-01

    In health care, tending is a process, which offers for the patients a continuous watching on, a control, a treatment, and the prevention of worsening of their medical status as well as the reduction of their complaints. In the article, some fundamental segments of tending in addictology are reviewed, particularly paying attention to whom, how, where and how long to take care. On the basis of literature, the author stresses whatever method is used to treat addict patients it is more beneficial to society than the avoidance of any intervention due to the negligence of the problem. Addictology has lost a lot from its power in Hungary. The author recommends the introduction of the methods of health quality assurance to decrease the effect of negative trends seen in addictology. The paper also deals with special patient groups including homeless clients, adolescents, elderly and pregnant patients as well as health care professionals. The author critically mentions the double communication of society, the dual-face character of politics and has the opinion that competences are not clear making the situation confused. As a mistake of the point of view is it regarded that the addictological problems are classified as to belonging to the authority of psychiatry. It is emphasized that multidisciplinary approach is needed to understand the problem and to treat the client. General screening for addictological diseases does not seem possible in the light of low capacity of the system, but the screening of adolescents and pregnant women is definitely recommended. And finally, a financial support for medicines to prevent craving, a moratorium for the continuous changing of rules and law, the sponsoring of harm reduction programs as well as a better utilization of opportunities offered by local drug coordinating boards are proposed.

  9. A Perspective on the Landscape Problem

    NASA Astrophysics Data System (ADS)

    Smolin, Lee

    2013-01-01

    I discuss the historical roots of the landscape problem and propose criteria for its successful resolution. This provides a perspective to evaluate the possibility to solve it in several of the speculative cosmological scenarios under study including eternal inflation, cosmological natural selection and cyclic cosmologies. Invited contribution for a special issue of Foundations of Physics titled Forty Years Of String Theory: Reflecting On the Foundations.

  10. Food sustainability: problems, perspectives and solutions.

    PubMed

    Garnett, Tara

    2013-02-01

    The global food system makes a significant contribution to climate changing greenhouse gas emissions with all stages in the supply chain, from agricultural production through processing, distribution, retailing, home food preparation and waste, playing a part. It also gives rise to other major environmental impacts, including biodiversity loss and water extraction and pollution. Policy makers are increasingly aware of the need to address these concerns, but at the same time they are faced with a growing burden of food security and nutrition-related problems, and tasked with ensuring that there is enough food to meet the needs of a growing global population. In short, more people need to be fed better, with less environmental impact. How might this be achieved? Broadly, three main 'takes' or perspectives, on the issues and their interactions, appear to be emerging. Depending on one's view point, the problem can be conceptualised as a production challenge, in which case there is a need to change how food is produced by improving the unit efficiency of food production; a consumption challenge, which requires changes to the dietary drivers that determine food production; or a socio-economic challenge, which requires changes in how the food system is governed. This paper considers these perspectives in turn, their implications for nutrition and climate change, and their strengths and weaknesses. Finally, an argument is made for a reorientation of policy thinking which uses the insights provided by all three perspectives, rather than, as is the situation today, privileging one over the other.

  11. Aha: A Connectionist Perspective on Problem Solving

    DTIC Science & Technology

    1988-06-08

    DOCUMENTATION PAGE 7, -REPORtT SEC.𔃾l CASPFC.A’C ON R7ESRtC’ vE %MARK.%GS Unclassif led 22 SECRITY C ASSPFCATION Aur~oRifv 3 ; S’R @Bu ON AjALA81L 3 F...Typically, the search perspective has been used to desc ,.,e problem solving behavior occurring on a macro-level time scale of seconds as opposed to the...unit /. The constants S, E and / (all set to .05 for the simulations described below) scale the strength of the external input, the excitatory input from

  12. Ciguatera: Australian perspectives on a global problem.

    PubMed

    Lewis, Richard J

    2006-12-01

    Ciguatera is a global disease caused by the consumption of certain warm-water fish that have accumulated orally effective levels of sodium channel activator toxins (ciguatoxins) through the marine food chain. Symptoms of ciguatera arising from the consumption of ciguateric fish include a range of gastrointestinal, neurological and cardiovascular disturbances. This review examines progress in our understanding of ciguatera from an Australian perspective, especially the laboratory-based research into the problem that was initiated by the late "Bob" Endean at the University of Queensland.

  13. A Set-Oriented Perspective on Solving Counting Problems

    ERIC Educational Resources Information Center

    Lockwood, Elise

    2014-01-01

    In this article, I present the notion of a set-oriented perspective for solving counting problems that emerged during task-based interviews with postsecondary students. Framing the findings within Harel's "ways of thinking", I argue that students may benefit from this perspective, in which they view attending to sets of outcomes as…

  14. New Perspectives on Human Problem Solving

    ERIC Educational Resources Information Center

    Goldstone, Robert L.; Pizlo, Zygmunt

    2009-01-01

    In November 2008 at Purdue University, the 2nd Workshop on Human Problem Solving was held. This workshop, which was a natural continuation of the first workshop devoted almost exclusively to optimization problems, addressed a wider range of topics that reflect the scope of the "Journal of Problem Solving." The workshop was attended by 35…

  15. New Perspectives on Human Problem Solving

    ERIC Educational Resources Information Center

    Goldstone, Robert L.; Pizlo, Zygmunt

    2009-01-01

    In November 2008 at Purdue University, the 2nd Workshop on Human Problem Solving was held. This workshop, which was a natural continuation of the first workshop devoted almost exclusively to optimization problems, addressed a wider range of topics that reflect the scope of the "Journal of Problem Solving." The workshop was attended by 35…

  16. Perspectives on the Consecutive Pages Problem

    ERIC Educational Resources Information Center

    Srinivasan, V. K.

    2011-01-01

    This article presents different approaches to a problem, dubbed by the author as "the consecutive pages problem". The aim of this teaching-oriented article is to promote the teaching of abstract concepts in mathematics, by selecting a challenging amusement problem and then presenting various solutions in such a way that it can engage the attention…

  17. [Non-statistical biomathematics: opinions, perspectives, problems].

    PubMed

    Peil, J

    1981-01-01

    By way of tracing the position of biomathematics and its main subjects a discussion is given of the mutual relations between the branches of natural sciences and mathematics within the hierarchically structured building of science. The general possibilities of a mathematical expressing and description of the biological features "complexity", "variability", and "discontinuity" and the limits are shown of validity of mathematical formulations in the field of biology. To this point representative opinions of research workers are quoted. The only direct ways of application of mathematics in biology seems to be the treatment of "variability" by statistical biomathematical means which offers the mathematical services in the design of experiments as well as in the quantitative-descriptive evaluation of experimental results. Aside from these ways a direct mathematical approach to biology is thought of being questionable because of the large differences between the levels of abstraction on which these two disciplines work. But the thesis is stated and supported that biophysics and biocybernetics as mediators provide an appropriate approach of the mathematics to such biological problems which arise from "complexity" and from "discontinuity". The kind of biomathematical tools, the goal of a biomathematical analysis, and the results of such an analysis get their meaning from the biophysical or biocybernetical modelling in which they are embedded. Example of working out of biomathematical methods and of application these methods are added.

  18. International Student Mobility: Problems and Perspectives.

    ERIC Educational Resources Information Center

    Escolano, Agustin

    1986-01-01

    An examination of international student mobility looks at the general trend toward increased mobility, problems of conflicting attitudes and expectations, and considerations of curriculum and credentials. (MSE)

  19. A Cognitive Perspective on Language Learners' Listening Comprehension Problems.

    ERIC Educational Resources Information Center

    Goh, Christine C. M.

    2000-01-01

    Offers a cognitive perspective on the comprehension problems of second language listeners by identifying real-time listening difficulties faced by English-as-Second-Language learners and examining these difficulties within the three-phase model of language comprehension proposed by Anderson (1995). Shows ten problems that occurred during the…

  20. Dynamic Problem Solving: A New Assessment Perspective

    ERIC Educational Resources Information Center

    Greiff, Samuel; Wustenberg, Sascha; Funke, Joachim

    2012-01-01

    This article addresses two unsolved measurement issues in dynamic problem solving (DPS) research: (a) unsystematic construction of DPS tests making a comparison of results obtained in different studies difficult and (b) use of time-intensive single tasks leading to severe reliability problems. To solve these issues, the MicroDYN approach is…

  1. Dynamic Problem Solving: A New Assessment Perspective

    ERIC Educational Resources Information Center

    Greiff, Samuel; Wustenberg, Sascha; Funke, Joachim

    2012-01-01

    This article addresses two unsolved measurement issues in dynamic problem solving (DPS) research: (a) unsystematic construction of DPS tests making a comparison of results obtained in different studies difficult and (b) use of time-intensive single tasks leading to severe reliability problems. To solve these issues, the MicroDYN approach is…

  2. A Cognitive Perspective Applied to Emancipation Problems.

    ERIC Educational Resources Information Center

    Wood, William D.

    1980-01-01

    Problems described include over-dependency, vacillation about dependency, and resistance to authority. The plan for intervention entails accurate reflection of cognitions, capitalizes on anti-expectation, and minimizes complications that a vigorously confrontive method often intensifies with adolescents. (Author/RH)

  3. Public perspectives on the "wildfire problem."

    Treesearch

    Antony S. Cheng; Dennis R. Becker

    2005-01-01

    Just as wildland fire managers must have a working knowledge of fire behavior, they must also understand the social dimensions of wildland fire in order to effectively engage the public.Social scientists are therefore gathering information about public attitudes toward wildland fire and wildfire mitigation. How do people see the "wildfire problem"? What...

  4. Rio Grande rift: problems and perspectives

    SciTech Connect

    Baldridge, W.S.; Olsen, K.H.; Callender, J.F.

    1984-01-01

    Topics and ideas addressed include: (1) the regional extent of the Rio Grande rift; (2) the structure of the crust and upper mantle; (3) whether the evidence for an axile dike in the lower crust is compelling; (4) the nature of faulting and extension in the crust; and (5) the structural and magmatic development of the rift. 88 references, 5 figures.

  5. PREFACE: The random search problem: trends and perspectives The random search problem: trends and perspectives

    NASA Astrophysics Data System (ADS)

    da Luz, Marcos G. E.; Grosberg, Alexander; Raposo, Ernesto P.; Viswanathan, Gandhi M.

    2009-10-01

    very important to solve computationally complex problems (e.g., protein folding), which involve optimizations in very high dimensional energy landscapes. On the other hand, random searches can also be studied from the perspective of diffusion and transport properties which is an important topic in condensed matter and statistical physics. For instance, the features of light scattered in a media, where the scatterers have a power-law distribution of sizes in many aspects, may resemble the patterns generated by a searcher performing Lévy walks. There are many questions related to random searches: how the searcher moves or should move, what are the patterns generated during the locomotion, how do the encounter rates depend on parameters of the search, etc. But perhaps, the most well known issue is how to optimize the search for specific target scenarios. The optimization can be in either continuous or discrete environments, when the information available is limited. The answer to this question determines specific strategies of movement that would maximize some properly defined search efficiency measure. The relevance of the question stems from the fact that the strategy-dynamics represents one of the most important factors that modulate the rate of encounters (e.g., the encounter rate between predator and prey). In the general context, strategy choices can be essential in determining the outcome and thus the success of a given search. For instance, realistic searches—and locomotion in general—require the expenditure of energy. Thus, inefficient search could deplete energy reserves (e.g., fat) and lead to rates of encounters below a minimum acceptable threshold (resulting in extinction of a species, for example). The framework of the random search `game' distinguishes between the two interacting players in a context of pursuit and chance. They are either a `searcher' (e.g., predator, protein, radar, `crawler') or a `target' (e.g., prey, DNA sequence, a missing

  6. A geometrical perspective for the bargaining problem.

    PubMed

    Wong, Kelvin Kian Loong

    2010-04-26

    A new treatment to determine the Pareto-optimal outcome for a non-zero-sum game is presented. An equilibrium point for any game is defined here as a set of strategy choices for the players, such that no change in the choice of any single player will increase the overall payoff of all the players. Determining equilibrium for multi-player games is a complex problem. An intuitive conceptual tool for reducing the complexity, via the idea of spatially representing strategy options in the bargaining problem is proposed. Based on this geometry, an equilibrium condition is established such that the product of their gains over what each receives is maximal. The geometrical analysis of a cooperative bargaining game provides an example for solving multi-player and non-zero-sum games efficiently.

  7. Solving Math Problems Approximately: A Developmental Perspective

    PubMed Central

    Ganor-Stern, Dana

    2016-01-01

    Although solving arithmetic problems approximately is an important skill in everyday life, little is known about the development of this skill. Past research has shown that when children are asked to solve multi-digit multiplication problems approximately, they provide estimates that are often very far from the exact answer. This is unfortunate as computation estimation is needed in many circumstances in daily life. The present study examined 4th graders, 6th graders and adults’ ability to estimate the results of arithmetic problems relative to a reference number. A developmental pattern was observed in accuracy, speed and strategy use. With age there was a general increase in speed, and an increase in accuracy mainly for trials in which the reference number was close to the exact answer. The children tended to use the sense of magnitude strategy, which does not involve any calculation but relies mainly on an intuitive coarse sense of magnitude, while the adults used the approximated calculation strategy which involves rounding and multiplication procedures, and relies to a greater extent on calculation skills and working memory resources. Importantly, the children were less accurate than the adults, but were well above chance level. In all age groups performance was enhanced when the reference number was smaller (vs. larger) than the exact answer and when it was far (vs. close) from it, suggesting the involvement of an approximate number system. The results suggest the existence of an intuitive sense of magnitude for the results of arithmetic problems that might help children and even adults with difficulties in math. The present findings are discussed in the context of past research reporting poor estimation skills among children, and the conditions that might allow using children estimation skills in an effective manner. PMID:27171224

  8. Solving Math Problems Approximately: A Developmental Perspective.

    PubMed

    Ganor-Stern, Dana

    2016-01-01

    Although solving arithmetic problems approximately is an important skill in everyday life, little is known about the development of this skill. Past research has shown that when children are asked to solve multi-digit multiplication problems approximately, they provide estimates that are often very far from the exact answer. This is unfortunate as computation estimation is needed in many circumstances in daily life. The present study examined 4th graders, 6th graders and adults' ability to estimate the results of arithmetic problems relative to a reference number. A developmental pattern was observed in accuracy, speed and strategy use. With age there was a general increase in speed, and an increase in accuracy mainly for trials in which the reference number was close to the exact answer. The children tended to use the sense of magnitude strategy, which does not involve any calculation but relies mainly on an intuitive coarse sense of magnitude, while the adults used the approximated calculation strategy which involves rounding and multiplication procedures, and relies to a greater extent on calculation skills and working memory resources. Importantly, the children were less accurate than the adults, but were well above chance level. In all age groups performance was enhanced when the reference number was smaller (vs. larger) than the exact answer and when it was far (vs. close) from it, suggesting the involvement of an approximate number system. The results suggest the existence of an intuitive sense of magnitude for the results of arithmetic problems that might help children and even adults with difficulties in math. The present findings are discussed in the context of past research reporting poor estimation skills among children, and the conditions that might allow using children estimation skills in an effective manner.

  9. Finite Optimal Stopping Problems: The Seller's Perspective

    ERIC Educational Resources Information Center

    Hemmati, Mehdi; Smith, J. Cole

    2011-01-01

    We consider a version of an optimal stopping problem, in which a customer is presented with a finite set of items, one by one. The customer is aware of the number of items in the finite set and the minimum and maximum possible value of each item, and must purchase exactly one item. When an item is presented to the customer, she or he observes its…

  10. Finite Optimal Stopping Problems: The Seller's Perspective

    ERIC Educational Resources Information Center

    Hemmati, Mehdi; Smith, J. Cole

    2011-01-01

    We consider a version of an optimal stopping problem, in which a customer is presented with a finite set of items, one by one. The customer is aware of the number of items in the finite set and the minimum and maximum possible value of each item, and must purchase exactly one item. When an item is presented to the customer, she or he observes its…

  11. Perspective: the problem with the problem of professionalism.

    PubMed

    Lucey, Catherine; Souba, Wiley

    2010-06-01

    Enhancing professionalism is an important goal of all physicians, both as individuals and as members of educational and institutional communities of practice. Despite a great deal of dialogue and discourse, the medical profession struggles to ensure that all physicians are able to embrace and live the values of professionalism, notwithstanding the myriad stressors present in today's evolving health care environment. The authors suggest a move beyond the traditional educational paradigms focused on reinforcing rules, providing role models, rewarding right behavior, and removing those who falter, and that we instead view the problem of professionalism as a complex adaptive challenge requiring new learning. Approaching lapses in professionalism as a form of medical error may provide a fresh outlook and may lead to the development of successful strategies to help physicians realize their commitment to the values of professionalism, despite the inevitable challenges that arise throughout their careers.

  12. Apprehensions and problems after laryngectomy: Patients' perspective.

    PubMed

    Hirani, Ismail; Siddiqui, Atif Hafeez; Muhammad Khyani, Iqbal Abdul

    2015-11-01

    To evaluate the apprehensions, social, sexual and financial problems in patients with advanced laryngeal cancer after total laryngectomy and the impact of attending laryngeal club on these problems. The analytical study was conducted at the Dow Medical College and Civil Hospital Karachi from January 1996 to December 2011. Patients with total laryngectomy, operated for advanced laryngeal cancer at various centres of Sindh and Balochistan, attending Laryngeal Club of Pakistan, situated at Civil Hospital Karachi, were included. All the patients were evaluated through a questionnaire covering their apprehensions regarding social, sexual and financial impact on their lives after total laryngectomy. Data was analysed using SPSS 16. Of the 125 patients, 120(96%) were males, and 5(4%) were females; all housewives. The overall mean age was 54.8±0.5 years (range: 31-65 years). Further, 92(74%) participants were worried about financial uncertainty, while 84(67%) had regrets over loss of their voice; patients worried about losing family support and facing social rejection were 23(18%) and 15(12%) respectively. Only 7(5%) patients feared losing sexual relationship with their spouse. All these apprehensions were subdued after attending the Laryngeal Club of Pakistan. Severe financial impact was faced by 55(44%) patients due to loss of job, while 05(4%) had moderate impact due to change of job with lower income and 60(48%) patients had no financial problem. A good 102(82%) participants thought the support from their friends and family was upto their expectations; 98(78%) enjoyed satisfactory sex life although with reduced frequency of 1 to 2 intercourses per month; 21(17%) were having the frequency of 3-10 per month; and 3(2%) had more than 10 per month. Only 16(13%) patients were not involved in sexual relations with their spouses due to various reasons. Majority of laryngectomised patients expressed apprehensions and showed some social problems after laryngectomy, especially

  13. [Problems and perspectives in child health care].

    PubMed

    Nikolić, N; Gebauer, E; Jovanović, M; Rakić, D; Katanić, D

    1997-01-01

    Health care protection of children in Vojvodina is of particular importance regarding the negative natural birth rate. In spite of difficult economic situation, health care of children in Vojvodina is permanently carried out and would be significantly better in quality if the education of subspecialized personnel, space facilities, technological innovations, computerization and continuous education were available. Introduction of microanalytic laboratory techniques is essential for monitoring of prematures. Propagation of natural nutrition is an obligation of pediatricians. Respiratory diseases are still on the top of morbidity pyramid but tuberculosis is evidently in increase. An important health care problem is the expansion of allergic diseases. The progressive incidence of insulin-dependent diabetes is also evident. The spheres of juvenile gynecological endocrinology and andrology are still underdeveloped and that also applies to adolescent medicine. Toxicology remains an ongoing problem in pediatrics due to an increased number of accidental poisoning. Pediatricians-gastroenterologists are lacking while paediatric hepatology should be brought into more advanced state. Bone marrow and stem cells transplantation is in the responsibility of the Centre for haematology and oncology. Nephrology department lacks children's haemodialysis, ultrasound biopsy of kidneys, urodynamic analyses and new staff facilities. The increased number of survivals in case of children with with sequeles inevitably asks for better development of rehabilitation, prolonged treatment and teamwork. Intensive care and therapy department requires new staff and high technology capacities. Development of children's surgery department inevitably means the reconstruction of space facilities, modern equipment and new subspecializations. Preventive outpatient service is performed through systematic examinations. ultrasound diagnostics of hips, auditive screening and educational program activities

  14. [Aquaculture in the Netherlands: problems and perspectives].

    PubMed

    Hogendoorn, H

    1986-11-15

    New interest is being focussed on the more than 100-year-old field of fish culture in the Netherlands. The systems of production available show varying degrees of control of the fish and their environment, and they have a corresponding yield: 0.01-250 kg/m3/year. The recently developed recirculation systems (40-80 kg/m3) make possible the commercial production of luxury species of fish, independently of climatological conditions and having minimum effects on the environment. Some technical aspects of reproduction, housing, nutrition, growth, health control and marketing of the fish require further attention. But the absence of a solid tradition of fish culture is the main problem in the development of fish culture in the Netherlands today. Good fish stockmanship is required at farmers' level. And the organisation and governmental support, that turned agriculture into a highly successful industry, are also essential. For the moment, the most promising commercial prospects are provided by a number of luxury fish species: trout, salmon, eel, sole, turbot, tilapia, catfish, seabass and seabream. A joint effort may help to overcome the remaining technical and logistical uncertainties.

  15. Developmental neurotoxicity test guidelines: problems and perspectives.

    PubMed

    Tohyama, Chiharu

    2016-01-01

    Epidemiologic evidence has demonstrated associations between early life exposure to industrial chemicals and the occurrence of disease states, including cognitive and behavioral abnormalities, in children. The developing brain in the fetal and infantile periods is extremely vulnerable to chemicals because the blood-brain barrier is not completely formed during these periods. The Organisation for Economic Co-operation and Development (OECD) developmental neurotoxicity (DNT) test guideline, TG426, updated in 2007, comprises in vivo behavioral observational tests and other tests intended to assess DNT induced by exposure to industrial chemicals. These chemicals may enter the market without having been subjected to DNT testing, as DNT test data is not mandated by law at the time of chemical registration. In addition, proprietary rights have led to problems concerning the non-disclosure of industrial chemical toxicity test data, including DNT test data. To overcome the disadvantages of high-cost and low time efficiency of in vivo DNT tests, in vitro or in silico tests are the proposed alternatives, but it is unlikely that the results of such tests would reflect changes in higher brain functions. Accordingly, the current DNT test guidelines need to be revised to avoid overlooking or neglecting the occurrence of DNT induced by exposure to low doses of chemicals. This review also proposes the introduction of novel in vivo DNT testing methods in light of a cost-performance analysis.

  16. Big Data, Big Problems: A Healthcare Perspective.

    PubMed

    Househ, Mowafa S; Aldosari, Bakheet; Alanazi, Abdullah; Kushniruk, Andre W; Borycki, Elizabeth M

    2017-01-01

    Much has been written on the benefits of big data for healthcare such as improving patient outcomes, public health surveillance, and healthcare policy decisions. Over the past five years, Big Data, and the data sciences field in general, has been hyped as the "Holy Grail" for the healthcare industry promising a more efficient healthcare system with the promise of improved healthcare outcomes. However, more recently, healthcare researchers are exposing the potential and harmful effects Big Data can have on patient care associating it with increased medical costs, patient mortality, and misguided decision making by clinicians and healthcare policy makers. In this paper, we review the current Big Data trends with a specific focus on the inadvertent negative impacts that Big Data could have on healthcare, in general, and specifically, as it relates to patient and clinical care. Our study results show that although Big Data is built up to be as a the "Holy Grail" for healthcare, small data techniques using traditional statistical methods are, in many cases, more accurate and can lead to more improved healthcare outcomes than Big Data methods. In sum, Big Data for healthcare may cause more problems for the healthcare industry than solutions, and in short, when it comes to the use of data in healthcare, "size isn't everything."

  17. Problems of Teaching the Behaviorist Perspective in the Cognitive Revolution

    PubMed Central

    Abramson, Charles I.

    2013-01-01

    This article offers some personal reflections on the difficulty of teaching the behaviorist perspective in the psychology classroom. The problems focus on the inadequacy of introductory textbooks—which mischaracterize behaviorism, only present the most extreme behaviorist positions, make no mention of the neobehaviorist perspective, fail to discuss that there is no accepted criteria for determining what type of behavior is cognitive, and provide a definition of cognition that is, not only inconsistent across texts, but so broad as to overshadow the behaviorist contributions. Suggestions are provided for instructors on how to present to their students an accurate portrayal of behaviorism. PMID:25379226

  18. Parenting Education in Australia: A Structural Perspective.

    ERIC Educational Resources Information Center

    Allan, June

    This paper offers critical reflections on parenting education in its social context. The paper is informed by a feminist perspective, and by a structural approach to practice that emphasizes the importance of changing social structures. An introductory section explores the impact of the ideologies of the traditional family, and of motherhood and…

  19. Parenting Education in Australia: A Structural Perspective.

    ERIC Educational Resources Information Center

    Allan, June

    This paper offers critical reflections on parenting education in its social context. The paper is informed by a feminist perspective, and by a structural approach to practice that emphasizes the importance of changing social structures. An introductory section explores the impact of the ideologies of the traditional family, and of motherhood and…

  20. Nursing Instructor and Students’ Perspectives on Clinical Education Apprenticeship Problems

    PubMed Central

    Hasanpour-Dehkordi, Ali

    2016-01-01

    Introduction Different problems might lead to reduction in the efficiency of nursing students’ apprenticeship education and solving those problems. Aim This study was conducted to determine nursing internship problems from the perspective of trainers and students. Materials and Methods In this descriptive cross-sectional study, 20 trainers and 43 senior students of nursing were selected using census method. A researcher-made questionnaire was used to collect data. Total internal consistency (α) of the questionnaire was 0.88 and had proper convergent validity. SPSS was used to analyse data with applying descriptive and inferential statistics. Results More than 50% considered their course relatively weak or weak in helping intern nurses to acquire comprehensive view of the nursing profession that takes a social perspective into account, skills required for the processes of nursing and instructing patients. Problems such as insufficient access to welfare and educational facilities, lack of co-operation among clinical team and scattering of internship sessions during a course were mentioned by nurses and their trainers. They believed that changes must take place in the way internship courses are carried out. Conclusion Although the internship courses seem to achieve their aim of improving students’ skills and independence in providing different nursing services to students and their trainers generally have a positive attitude towards such courses, there are still problems in effective exercise of the training. PMID:27790467

  1. A Perspective for Examining the Link between Problem Posing and Problem Solving

    ERIC Educational Resources Information Center

    Cai, Jinfa; Hwang, Stephen

    2003-01-01

    In a previous study, we posited a link between Chinese sixth grade students' problem solving and problem posing based on a pattern-formation strategy (Cai & Hwang, 2002). A similar parallel structure between problem solving and problem posing did not obtain for the U.S. sixth graders in the study. The present study attempts to locate this type of…

  2. Structured interviewing: avoiding selection problems.

    PubMed

    Pursell, E D; Campion, M A; Gaylord, S R

    1980-11-01

    In place of the old-fashioned, casual interview, which is unreliable and occasionally invalid in the context of EEO and affirmative action developments, the authors propose the adoption of structured interviewing for job selection. They contend that objective testing--oral, written and physical--would be more reliable, avoid the labyrinth of EEO, and ultimately yield better candidates for the jobs offered.

  3. Three P's in Cosmology: Progress, Problems, and Perspectives

    NASA Astrophysics Data System (ADS)

    Dolgov, A. D.

    2014-04-01

    A review on the development of cosmology for a diverse audience is presented. The first historical part is devoted to the works done half a century ago with an emphasize to those performed in Russia (or more precisely, in the Soviet Union). Then the recent data on the cosmic microwave background raditation is discussed and the impact of these data on the neutrino mass and the number of neutrino species is considered. The latter is compared with the results obtained from the big bang nucleosynthesis. Next, a short description and history of the cosmological inflation is presented. The basics of the standard cosmological model and the problems of dark matter and dark energy are considered at the end of the fist section entitled "Progress". In the next short section, "Problems", one can find a list of the unsolved cosmological and astrophysical problems, which is by no means fully comprehensive. The last supershort section contains a few words about the perspectives of future development.

  4. OPEN PROBLEM: Spatially localized structures in dissipative systems: open problems

    NASA Astrophysics Data System (ADS)

    Knobloch, E.

    2008-04-01

    Stationary spatially localized structures, sometimes called dissipative solitons, arise in many interesting and important applications, including buckling of slender structures under compression, nonlinear optics, fluid flow, surface catalysis, neurobiology and many more. The recent resurgence in interest in these structures has led to significant advances in our understanding of the origin and properties of these states, and these in turn suggest new questions, both general and system-specific. This paper surveys these results focusing on open problems, both mathematical and computational, as well as on new applications.

  5. Reading the problem family: post-structuralism and the analysis of social problems.

    PubMed

    Reekie, G

    1994-01-01

    Post-structuralist theory questions the rational pursuit of an underlying 'truth' that often characterizes social scientific inquiry, proposing instead the simultaneous existence of multiple and often contradictory truths. The problem family can, from this perspective, only be known through the different discourses that produce it. This paper suggests some of the political advantages of developing methods of reading 'problems' related to drugs and alcohol. Without this critical attention to language, we risk perpetuating the ways in which problems are talked about and thought about. Drawing on examples from debates surrounding teenage pregnancy and youth drinking, the paper argues that post-structuralism allows us to analyse the specific ways in which professional discourses write social problems, and hence to own them and to re-write them.

  6. Structural perspectives on antimicrobial chemokines

    PubMed Central

    Nguyen, Leonard T.; Vogel, Hans J.

    2012-01-01

    Chemokines are best known as signaling proteins in the immune system. Recently however, a large number of human chemokines have been shown to exert direct antimicrobial activity. This moonlighting activity appears to be related to the net high positive charge of these immune signaling proteins. Chemokines can be divided into distinct structural elements and some of these have been studied as isolated peptide fragments that can have their own antimicrobial activity. Such peptides often encompass the α-helical region found at the C-terminal end of the parent chemokines, which, similar to other antimicrobial peptides, adopt a well-defined membrane-bound amphipathic structure. Because of their relatively small size, intact chemokines can be studied effectively by NMR spectroscopy to examine their structures in solution. In addition, NMR relaxation experiments of intact chemokines can provide detailed information about the intrinsic dynamic behavior; such analyses have helped for example to understand the activity of TC-1, an antimicrobial variant of CXCL7/NAP-2. With chemokine dimerization and oligomerization influencing their functional properties, the use of NMR diffusion experiments can provide information about monomer-dimer equilibria in solution. Furthermore, NMR chemical shift perturbation experiments can be used to map out the interface between self-associating subunits. Moreover, the unusual case of XCL1/lymphotactin presents a chemokine that can interconvert between two distinct folds in solution, both of which have been elucidated. Finally, recent advances have allowed for the determination of the structures of chemokines in complex with glycosaminoglycans, a process that could interfere with their antimicrobial activity. Taken together, these studies highlight several different structural facets that contribute to the way in which chemokines exert their direct microbicidal actions. PMID:23293636

  7. Organizational Structure and Complex Problem Solving

    ERIC Educational Resources Information Center

    Becker, Selwyn W.; Baloff, Nicholas

    1969-01-01

    The problem-solving efficiency of different organization structures is discussed in relation to task requirements and the appropriate organizational behavior, to group adaptation to a task over time, and to various group characteristics. (LN)

  8. Trinucleotide Repeats: A Structural Perspective

    PubMed Central

    Almeida, Bruno; Fernandes, Sara; Abreu, Isabel A.; Macedo-Ribeiro, Sandra

    2013-01-01

    Trinucleotide repeat (TNR) expansions are present in a wide range of genes involved in several neurological disorders, being directly involved in the molecular mechanisms underlying pathogenesis through modulation of gene expression and/or the function of the RNA or protein it encodes. Structural and functional information on the role of TNR sequences in RNA and protein is crucial to understand the effect of TNR expansions in neurodegeneration. Therefore, this review intends to provide to the reader a structural and functional view of TNR and encoded homopeptide expansions, with a particular emphasis on polyQ expansions and its role at inducing the self-assembly, aggregation and functional alterations of the carrier protein, which culminates in neuronal toxicity and cell death. Detail will be given to the Machado-Joseph Disease-causative and polyQ-containing protein, ataxin-3, providing clues for the impact of polyQ expansion and its flanking regions in the modulation of ataxin-3 molecular interactions, function, and aggregation. PMID:23801983

  9. Spider pheromones - a structural perspective.

    PubMed

    Schulz, Stefan

    2013-01-01

    Spiders use pheromones for sexual communication, as do other animals such as insects. Nevertheless, knowledge about their chemical structure, function, and biosynthesis is only now being unraveled. Many studies have shown the existence of spider pheromones, but the responsible compounds have been elucidated in only a few cases. This review focuses on a structural approach because we need to know the involved chemistry if we are to understand fully the function of a pheromonal communication system. Pheromones from members of the spider families Pholcidae, Araneidae, Linyphiidae, Agenelidae, and Ctenidae are currently being identified and will be discussed in this review. Some of these compounds belong to compound classes not known from other arthropod pheromones, such as citric acid derivatives or acylated amino acids, whereas others originate from more common fatty acid metabolism. Their putative biosynthesis, their function, and the identification methods used will be discussed. Furthermore, other semiochemicals and the chemistry of apolar surface lipids that potentially might be used by spiders for communication are described briefly.

  10. Structural Perspective on Enzymatic Halogenation

    PubMed Central

    2008-01-01

    Simple halogen substituents frequently afford key structural features that account for the potency and selectivity of natural products, including antibiotics and hormones. For example, when a single chlorine atom on the antibiotic vancomycin is replaced by hydrogen, the resulting antibacterial activity decreases by up to 70% (HarrisC. M.; KannanR.; KopeckaH.; HarrisT. M.J. Am. Chem. Soc.1985, 107, 6652−6658). This Account analyzes how structure underlies mechanism in halogenases, the molecular machines designed by nature to incorporate halogens into diverse substrates. Traditional synthetic methods of integrating halogens into complex molecules are often complicated by a lack of specificity and regioselectivity. Nature, however, has developed a variety of elegant mechanisms for halogenating specific substrates with both regio- and stereoselectivity. An improved understanding of the biological routes toward halogenation could lead to the development of novel synthetic methods for the creation of new compounds with enhanced functions. Already, researchers have co-opted a fluorinase from the microorganism Streptomyces cattleya to produce 18F-labeled molecules for use in positron emission tomography (PET) (DengH.; CobbS. L.; GeeA. D.; LockhartA.; MartarelloL.; McGlincheyR. P.; O’HaganD.; OnegaM.Chem. Commun.2006, 652−654). Therefore, the discovery and characterization of naturally occurring enzymatic halogenation mechanisms has become an active area of research. The catalogue of known halogenating enzymes has expanded from the familiar haloperoxidases to include oxygen-dependent enzymes and fluorinases. Recently, the discovery of a nucleophilic halogenase that catalyzes chlorinations has expanded the repertoire of biological halogenation chemistry (DongC.; HuangF.; DengH.; SchaffrathC.; SpencerJ. B.; O’HaganD.; NaismithJ. H.Nature2004, 427, 561−56514765200). Structural characterization has provided a basis toward a mechanistic understanding of the specificity

  11. Structural damage assessment as an identification problem

    NASA Technical Reports Server (NTRS)

    Hajela, Prabhat; Soeiro, F. J.

    1989-01-01

    Damage assessment of structural assemblies is treated as an identification problem. A brief review of identification methods is first presented with particular focus on the output error approach. The use of numerical optimization methods in identifying the location and extent of damage in structures is studied. The influence of damage on eigenmode shapes and static displacements is explored as a means of formulating a measure of damage in the structure. Preliminary results obtained in this study are presented and special attention is directed at the shortcomings associated with the nonlinear programming approach to solving the optimization problem.

  12. A combinatorial perspective of the protein inference problem.

    PubMed

    Yang, Chao; He, Zengyou; Yu, Weichuan

    2013-01-01

    In a shotgun proteomics experiment, proteins are the most biologically meaningful output. The success of proteomics studies depends on the ability to accurately and efficiently identify proteins. Many methods have been proposed to facilitate the identification of proteins from peptide identification results. However, the relationship between protein identification and peptide identification has not been thoroughly explained before. In this paper, we devote ourselves to a combinatorial perspective of the protein inference problem. We employ combinatorial mathematics to calculate the conditional protein probabilities (protein probability means the probability that a protein is correctly identified) under three assumptions, which lead to a lower bound, an upper bound, and an empirical estimation of protein probabilities, respectively. The combinatorial perspective enables us to obtain an analytical expression for protein inference. Our method achieves comparable results with ProteinProphet in a more efficient manner in experiments on two data sets of standard protein mixtures and two data sets of real samples. Based on our model, we study the impact of unique peptides and degenerate peptides (degenerate peptides are peptides shared by at least two proteins) on protein probabilities. Meanwhile, we also study the relationship between our model and ProteinProphet. We name our program ProteinInfer. Its Java source code, our supplementary document and experimental results are available at: >http://bioinformatics.ust.hk/proteininfer.

  13. Structured eigenvalue problems for rational gauss quadrature

    NASA Astrophysics Data System (ADS)

    Fasino, Dario; Gemignani, Luca

    2007-08-01

    The connection between Gauss quadrature rules and the algebraic eigenvalue problem for a Jacobi matrix was first exploited in the now classical paper by Golub and Welsch (Math. Comput. 23(106), 221?230, 1969). From then on many computational problems arising in the construction of (polynomial) Gauss quadrature formulas have been reduced to solving direct and inverse eigenvalue problems for symmetric tridiagonals. Over the last few years (rational) generalizations of the classical Gauss quadrature formulas have been studied, i.e., formulas integrating exactly in spaces of rational functions. This paper wants to illustrate that stable and efficient procedures based on structured numerical linear algebra techniques can also be devised for the solution of the eigenvalue problems arising in the field of rational Gauss quadrature.

  14. Unifying Temporal and Structural Credit Assignment Problems

    NASA Technical Reports Server (NTRS)

    Agogino, Adrian K.; Tumer, Kagan

    2004-01-01

    Single-agent reinforcement learners in time-extended domains and multi-agent systems share a common dilemma known as the credit assignment problem. Multi-agent systems have the structural credit assignment problem of determining the contributions of a particular agent to a common task. Instead, time-extended single-agent systems have the temporal credit assignment problem of determining the contribution of a particular action to the quality of the full sequence of actions. Traditionally these two problems are considered different and are handled in separate ways. In this article we show how these two forms of the credit assignment problem are equivalent. In this unified frame-work, a single-agent Markov decision process can be broken down into a single-time-step multi-agent process. Furthermore we show that Monte-Carlo estimation or Q-learning (depending on whether the values of resulting actions in the episode are known at the time of learning) are equivalent to different agent utility functions in a multi-agent system. This equivalence shows how an often neglected issue in multi-agent systems is equivalent to a well-known deficiency in multi-time-step learning and lays the basis for solving time-extended multi-agent problems, where both credit assignment problems are present.

  15. Obstacles and problems of ethical leadership from the perspective of nursing leaders: a qualitative content analysis.

    PubMed

    Barkhordari-Sharifabad, Maasoumeh; Ashktorab, Tahereh; Atashzadeh-Shoorideh, Foroozan

    2017-01-01

    In the nursing profession, leadership plays a significant role in creating motivation and thus enabling nurses to provide high quality care. Ethics is an essential component of leadership qualifications and the ethical leader can help create an ethical atmosphere, offer ethical guidance, and ensure the occupational satisfaction of personnel through prioritizing moralities. However, some issues prevent the implementation of this type of leadership by nursing leaders. The aim of this study was to identify and describe some problems and obstacles in ethical leadership faced by nursing leaders, and to help them achieve more accurate information and broader perspective in this field. The present study was conducted using a qualitative approach and content analysis. A total of 14 nursing managers and educators were selected purposefully, and deep and semi-structured interviews were conducted with them. Content analysis was performed using an inductive approach. Three main categories were obtained after data analysis: ethical, cultural and managerial problems. "Ethical problems" pertain to doubt in ethical actions, ethical conflicts and ethical distress; "cultural problems" include organizational and social culture; and "managerial problems" are connected to organizational and staff-related issues. Nursing leaders put forth various aspects of the problems associated with ethical leadership in the clinical setting. This style of leadership could be promoted by developing suitable programs and providing clear-cut strategies for removing the current obstacles and correcting the organizational structure. This can lead to ethical improvement in nursing leaders and subsequently the nurses.

  16. Ecological effects of oil shale development: problems, perspectives, and approaches

    SciTech Connect

    Hakonson, T.E.; White. G.C.

    1980-01-01

    Although current oil shale developments in the Piceance Basin appear to have had little impact on ecosystems, it is important to recognize that planned expansion of the industry in the Basin will greatly magnify the potential for serious perturbations of the Piceance environs. The relatively small scale of the present oil shale activities in the Basin provides the biologist with a unique opportunity to establish and conduct quantitative studies designed to measure impacts as they occur. This paper is intended to focus attention on some of the problems, perspectives and recommended approaches to conducting ecosystem effects studies that will provide criteria for evaluation and mitigation of impacts should they occur. The purpose of this paper is not to criticize past and current environmental studies on oil shale, but in light of anticipated growth of the industry, to focus attention on the need to carefully define, design and execute ecological effects studies to quantify and provide mitigation criteria for impacts that will undoubtedly result from accelerated industry activities.

  17. Two-particle problem in comblike structures.

    PubMed

    Agliari, Elena; Cassi, Davide; Cattivelli, Luca; Sartori, Fabio

    2016-05-01

    Encounters between walkers performing a random motion on an appropriate structure can describe a wide variety of natural phenomena ranging from pharmacokinetics to foraging. On homogeneous structures the asymptotic encounter probability between two walkers is (qualitatively) independent of whether both walkers are moving or one is kept fixed. On infinite comblike structures this is no longer the case and here we deepen the mechanisms underlying the emergence of a finite probability that two random walkers will never meet, while one single random walker is certain to visit any site. In particular, we introduce an analytical approach to address this problem and even more general problems such as the case of two walkers with different diffusivity, particles walking on a finite comb and on arbitrary bundled structures, possibly in the presence of loops. Our investigations are both analytical and numerical and highlight that, in general, the outcome of a reaction involving two reactants on a comblike architecture can strongly differ according to whether both reactants are moving (no matter their relative diffusivities) or only one is moving and according to the density of shortcuts among the branches.

  18. Two-particle problem in comblike structures

    NASA Astrophysics Data System (ADS)

    Agliari, Elena; Cassi, Davide; Cattivelli, Luca; Sartori, Fabio

    2016-05-01

    Encounters between walkers performing a random motion on an appropriate structure can describe a wide variety of natural phenomena ranging from pharmacokinetics to foraging. On homogeneous structures the asymptotic encounter probability between two walkers is (qualitatively) independent of whether both walkers are moving or one is kept fixed. On infinite comblike structures this is no longer the case and here we deepen the mechanisms underlying the emergence of a finite probability that two random walkers will never meet, while one single random walker is certain to visit any site. In particular, we introduce an analytical approach to address this problem and even more general problems such as the case of two walkers with different diffusivity, particles walking on a finite comb and on arbitrary bundled structures, possibly in the presence of loops. Our investigations are both analytical and numerical and highlight that, in general, the outcome of a reaction involving two reactants on a comblike architecture can strongly differ according to whether both reactants are moving (no matter their relative diffusivities) or only one is moving and according to the density of shortcuts among the branches.

  19. Investigation of Acoustic-Structure Interaction Problems

    NASA Astrophysics Data System (ADS)

    Hong, Kin Loong

    1995-01-01

    A new procedure to formulate and analyze vibration problems of structural-acoustic coupled system has been established. At first, free vibration analysis of the acoustic system by the modal expansion method was applied for elliptic cavities, then the system equations of structure -acoustic coupled systems are formulated utilizing the concept of the equivalent mass source. The modal expansion method and a matrix transformation technique are used to solve the free and forced vibration problems. The final formulation of this method in the free vibration problems gives rise to a standard eigenvalue problem. The validity of the procedure is verified by comparing its results with the exact solutions for a one-dimensional coupled system. Parameters dictating coupling effects are also identified and discussed. In the final part of the dissertation, a new solution method was introduced to solve the forced response of acoustic -structure coupled system, which includes damping and absorbing elements. The new method proposed here does not require any matrix inversion as has been used in conventional methods. The method proposed here also has a better numerical efficiency. The other advantage of the method is that the effect of the absorbing material on the system response can be modeled as a virtual sound source with its own magnitude and phase. The system frequency response functions can be expressed as a summation of the uncoupled component modes of the system, The procedure for the forced response solution was again confirmed by comparing its results with the exact solution available for the one dimensional case. Possible applications of the method are also discussed.

  20. Solving subsurface structural problems using a computer

    SciTech Connect

    Witte, D.M. )

    1987-02-01

    Until recently, the solution of subsurface structural problems has required a combination of graphical construction, trigonometry, time, and patience. Recent advances in software available for both mainframe and microcomputers now reduce the time and potential error of these calculations by an order of magnitude. Software for analysis of deviated wells, three point problems, apparent dip, apparent thickness, and the intersection of two planes, as well as the plotting and interpretation of these data can be used to allow timely and accurate exploration or operational decisions. The available computer software provides a set of utilities, or tools, rather than a comprehensive, intelligent system. The burden for selection of appropriate techniques, computation methods, and interpretations still lies with the explorationist user.

  1. The relativistic inverse stellar structure problem

    SciTech Connect

    Lindblom, Lee

    2014-01-14

    The observable macroscopic properties of relativistic stars (whose equations of state are known) can be predicted by solving the stellar structure equations that follow from Einstein’s equation. For neutron stars, however, our knowledge of the equation of state is poor, so the direct stellar structure problem can not be solved without modeling the highest density part of the equation of state in some way. This talk will describe recent work on developing a model independent approach to determining the high-density neutron-star equation of state by solving an inverse stellar structure problem. This method uses the fact that Einstein’s equation provides a deterministic relationship between the equation of state and the macroscopic observables of the stars which are composed of that material. This talk illustrates how this method will be able to determine the high-density part of the neutron-star equation of state with few percent accuracy when high quality measurements of the masses and radii of just two or three neutron stars become available. This talk will also show that this method can be used with measurements of other macroscopic observables, like the masses and tidal deformabilities, which can (in principle) be measured by gravitational wave observations of binary neutron-star mergers.

  2. Techniques of structural family assessment: a qualitative analysis of how experts promote a systemic perspective.

    PubMed

    Nichols, Michael; Tafuri, Sydney

    2013-06-01

    The trajectory of assessment in structural family therapy moves from a linear perspective, in which problems are located in the identified patient, to an interactional perspective, in which problems are seen as involving other members of the family. Minuchin, Nichols, & Lee (2007) developed a 4-step model for assessing couples and families consisting of: (1) broadening the definition of the presenting complaint to include its context, (2) identifying problem-maintaining interactions, (3) a structurally focused exploration of the past, and (4) developing a shared vision of pathways to change. To study how experts actually implement this model, judges coded video recordings of 10 initial consultations conducted by three widely recognized structural family therapists. Qualitative analyses identified 25 distinct techniques that these clinicians used to challenge linear thinking and move families toward a systemic understanding of their problems. We discuss and locate these techniques in the framework of the 4-step model.

  3. Research Perspectives on Problem Solving in Elementary School Mathematics.

    ERIC Educational Resources Information Center

    Silver, Edward A.; Thompson, Alba G.

    1984-01-01

    Discusses five research areas offering guidance to people concerned about teaching problem solving in elementary schools. Areas are (1) components of problem difficulty; (2) the contribution of reading difficulties to problem-solving deficiencies; (3) characteristics of successful problem solvers; (4) children's use of problem-solving techniques…

  4. Computational strategies to address chromatin structure problems

    NASA Astrophysics Data System (ADS)

    Perišić, Ognjen; Schlick, Tamar

    2016-06-01

    While the genetic information is contained in double helical DNA, gene expression is a complex multilevel process that involves various functional units, from nucleosomes to fully formed chromatin fibers accompanied by a host of various chromatin binding enzymes. The chromatin fiber is a polymer composed of histone protein complexes upon which DNA wraps, like yarn upon many spools. The nature of chromatin structure has been an open question since the beginning of modern molecular biology. Many experiments have shown that the chromatin fiber is a highly dynamic entity with pronounced structural diversity that includes properties of idealized zig-zag and solenoid models, as well as other motifs. This diversity can produce a high packing ratio and thus inhibit access to a majority of the wound DNA. Despite much research, chromatin’s dynamic structure has not yet been fully described. Long stretches of chromatin fibers exhibit puzzling dynamic behavior that requires interpretation in the light of gene expression patterns in various tissue and organisms. The properties of chromatin fiber can be investigated with experimental techniques, like in vitro biochemistry, in vivo imagining, and high-throughput chromosome capture technology. Those techniques provide useful insights into the fiber’s structure and dynamics, but they are limited in resolution and scope, especially regarding compact fibers and chromosomes in the cellular milieu. Complementary but specialized modeling techniques are needed to handle large floppy polymers such as the chromatin fiber. In this review, we discuss current approaches in the chromatin structure field with an emphasis on modeling, such as molecular dynamics and coarse-grained computational approaches. Combinations of these computational techniques complement experiments and address many relevant biological problems, as we will illustrate with special focus on epigenetic modulation of chromatin structure.

  5. Firefighter Hand Anthropometry and Structural Glove Sizing: A New Perspective

    PubMed Central

    Hsiao, Hongwei; Whitestone, Jennifer; Kau, Tsui-Ying; Hildreth, Brooke

    2015-01-01

    Objective We evaluated the current use and fit of structural firefighting gloves and developed an improved sizing scheme that better accommodates the U.S. firefighter population. Background Among surveys, 24% to 30% of men and 31% to 62% of women reported experiencing problems with the fit or bulkiness of their structural firefighting gloves. Method An age-, race/ethnicity-, and gender-stratified sample of 863 male and 88 female firefighters across the United States participated in the study. Fourteen hand dimensions relevant to glove design were measured. A cluster analysis of the hand dimensions was performed to explore options for an improved sizing scheme. Results The current national standard structural firefighting glove-sizing scheme underrepresents firefighter hand size range and shape variation. In addition, mismatch between existing sizing specifications and hand characteristics, such as hand dimensions, user selection of glove size, and the existing glove sizing specifications, is significant. An improved glove-sizing plan based on clusters of overall hand size and hand/finger breadth-to-length contrast has been developed. Conclusion This study presents the most up-to-date firefighter hand anthropometry and a new perspective on glove accommodation. The new seven-size system contains narrower variations (standard deviations) for almost all dimensions for each glove size than the current sizing practices. Application The proposed science-based sizing plan for structural firefighting gloves provides a step-forward perspective (i.e., including two women hand model–based sizes and two wide-palm sizes for men) for glove manufacturers to advance firefighter hand protection. PMID:26169309

  6. Reading Multimodal Texts: Perceptual, Structural and Ideological Perspectives

    ERIC Educational Resources Information Center

    Serafini, Frank

    2010-01-01

    This article presents a tripartite framework for analyzing multimodal texts. The three analytical perspectives presented include: (1) perceptual, (2) structural, and (3) ideological analytical processes. Using Anthony Browne's picturebook "Piggybook" as an example, assertions are made regarding what each analytical perspective brings to the…

  7. Reading Multimodal Texts: Perceptual, Structural and Ideological Perspectives

    ERIC Educational Resources Information Center

    Serafini, Frank

    2010-01-01

    This article presents a tripartite framework for analyzing multimodal texts. The three analytical perspectives presented include: (1) perceptual, (2) structural, and (3) ideological analytical processes. Using Anthony Browne's picturebook "Piggybook" as an example, assertions are made regarding what each analytical perspective brings to the…

  8. Perspective-Taking in Structured and Unstructured Online Discussions

    ERIC Educational Resources Information Center

    Chadwick, Scott; Ralston, Ekaterina

    2010-01-01

    This study analyzes the extent to which students using web-based discussion boards show an increase in perspective-taking in structured and unstructured discussions. Messages from fifty-six students enrolled in one of two courses were content analyzed using Jarvela and Hakkinen's (2003) expansion of Selman's (1980) perspective-taking coding…

  9. Obstacles and problems of ethical leadership from the perspective of nursing leaders: a qualitative content analysis

    PubMed Central

    Barkhordari-Sharifabad, Maasoumeh; Ashktorab, Tahereh; Atashzadeh-Shoorideh, Foroozan

    2017-01-01

    In the nursing profession, leadership plays a significant role in creating motivation and thus enabling nurses to provide high quality care. Ethics is an essential component of leadership qualifications and the ethical leader can help create an ethical atmosphere, offer ethical guidance, and ensure the occupational satisfaction of personnel through prioritizing moralities. However, some issues prevent the implementation of this type of leadership by nursing leaders. The aim of this study was to identify and describe some problems and obstacles in ethical leadership faced by nursing leaders, and to help them achieve more accurate information and broader perspective in this field. The present study was conducted using a qualitative approach and content analysis. A total of 14 nursing managers and educators were selected purposefully, and deep and semi-structured interviews were conducted with them. Content analysis was performed using an inductive approach. Three main categories were obtained after data analysis: ethical, cultural and managerial problems. “Ethical problems” pertain to doubt in ethical actions, ethical conflicts and ethical distress; “cultural problems” include organizational and social culture; and “managerial problems” are connected to organizational and staff-related issues. Nursing leaders put forth various aspects of the problems associated with ethical leadership in the clinical setting. This style of leadership could be promoted by developing suitable programs and providing clear-cut strategies for removing the current obstacles and correcting the organizational structure. This can lead to ethical improvement in nursing leaders and subsequently the nurses. PMID:28523116

  10. Sound absorption by subwavelength membrane structures: A geometric perspective

    NASA Astrophysics Data System (ADS)

    Yang, Min; Li, Yong; Meng, Chong; Fu, Caixing; Mei, Jun; Yang, Zhiyu; Sheng, Ping

    2015-12-01

    Decorated membranes comprising a thin layer of elastic film with small rigid platelets fixed on top have been found to be efficient absorbers of low-frequency sound. In this work we consider the problem of sound absorption from a perspective aimed at deriving upper bounds under different scenarios, i.e., whether the sound is incident from one side only or from both sides, and whether there is a reflecting surface on the back side of the membrane. By considering the negligible thickness of the membrane, usually on the order of a fraction of one millimeter, we derive a relation showing that the sum of the incoming sound waves' (complex) pressure amplitudes, averaged over the area of the membrane, must be equal to that of the outgoing waves. By using this relation, and without going to any details of the wave solutions, it is shown that the maximum absorption achievable from one-sided incidence is 50%, while the maximum absorption with a back-reflecting surface can reach 100%. The latter was attained by the hybridized resonances. All the results are shown to be in excellent agreement with the experiments. This generalized perspective, when used together with the Green function's formalism, can be useful in gaining insights into the constraints on what are achievable in scatterings and absorption by thin film structures and delineating them.

  11. Team-Based Complex Problem Solving: A Collective Cognition Perspective

    ERIC Educational Resources Information Center

    Hung, Woei

    2013-01-01

    Today, much problem solving is performed by teams, rather than individuals. The complexity of these problems has exceeded the cognitive capacity of any individual and requires a team of members to solve them. The success of solving these complex problems not only relies on individual team members who possess different but complementary expertise,…

  12. Team-Based Complex Problem Solving: A Collective Cognition Perspective

    ERIC Educational Resources Information Center

    Hung, Woei

    2013-01-01

    Today, much problem solving is performed by teams, rather than individuals. The complexity of these problems has exceeded the cognitive capacity of any individual and requires a team of members to solve them. The success of solving these complex problems not only relies on individual team members who possess different but complementary expertise,…

  13. Problem Solving in the School Curriculum from a Design Perspective

    ERIC Educational Resources Information Center

    Toh, Tin Lam; Leong, Yew Hoong; Dindyal, Jaguthsing; Quek, Khiok Seng

    2010-01-01

    In this symposium, the participants discuss some preliminary data collected from their problem solving project which uses a design experiment approach. Their approach to problem solving in the school curriculum is in tandem with what Schoenfeld (2007) claimed: "Crafting instruction that would make a wide range of problem-solving strategies…

  14. Human pharmaceutical products in the environment - the "problem" in perspective.

    PubMed

    Taylor, David; Senac, Thomas

    2014-11-01

    Concerns about the potential for significant environmental impact from residues of human pharmaceuticals emerged at the beginning of the 21st century. Since then there has been an exponential rise in the number of publications and conferences on this "problem". However, this intense focus on human pharmaceuticals is misplaced. Pharmaceuticals do not consist of a coherent group of substances with similar chemical, structural, biological or toxicological properties. Pharmaceuticals are only identifiable from their use: in other words substances can be divided into two classes, those that are used as pharmaceuticals and those for which a possible pharmaceutical use has not yet been discovered. For example, nitro-glycerine, Warfarin and dimethyl fumarate, initially sold respectively as an explosive, a rodenticide and a mould inhibitor have subsequently all been used as pharmaceuticals. As analytical science advances, an increasing range of environmental contaminants, including pharmaceuticals, is being identified at sub μgL(-1) concentrations. Although, human and environmental exposure to these contaminants will be low, all of them need to be subjected to risk assessment on a case by case basis. Many of these substances, including human pharmaceuticals, may have little, if any, impact on human health or the environment, however for some substances there may be a significant risk and in these cases appropriate action should be taken. However considering all human pharmaceuticals as a special case, isolated from the wider range of emerging contaminants, is scientifically unjustifiable and diverts resources away from the consideration of other substances that may be of considerably more significance.

  15. The Perspective Structure of Visual Space

    PubMed Central

    2015-01-01

    Luneburg’s model has been the reference for experimental studies of visual space for almost seventy years. His claim for a curved visual space has been a source of inspiration for visual scientists as well as philosophers. The conclusion of many experimental studies has been that Luneburg’s model does not describe visual space in various tasks and conditions. Remarkably, no alternative model has been suggested. The current study explores perspective transformations of Euclidean space as a model for visual space. Computations show that the geometry of perspective spaces is considerably different from that of Euclidean space. Collinearity but not parallelism is preserved in perspective space and angles are not invariant under translation and rotation. Similar relationships have shown to be properties of visual space. Alley experiments performed early in the nineteenth century have been instrumental in hypothesizing curved visual spaces. Alleys were computed in perspective space and compared with reconstructed alleys of Blumenfeld. Parallel alleys were accurately described by perspective geometry. Accurate distance alleys were derived from parallel alleys by adjusting the interstimulus distances according to the size-distance invariance hypothesis. Agreement between computed and experimental alleys and accommodation of experimental results that rejected Luneburg’s model show that perspective space is an appropriate model for how we perceive orientations and angles. The model is also appropriate for perceived distance ratios between stimuli but fails to predict perceived distances. PMID:27648222

  16. The Perspective Structure of Visual Space.

    PubMed

    Erkelens, Casper J

    2015-10-01

    Luneburg's model has been the reference for experimental studies of visual space for almost seventy years. His claim for a curved visual space has been a source of inspiration for visual scientists as well as philosophers. The conclusion of many experimental studies has been that Luneburg's model does not describe visual space in various tasks and conditions. Remarkably, no alternative model has been suggested. The current study explores perspective transformations of Euclidean space as a model for visual space. Computations show that the geometry of perspective spaces is considerably different from that of Euclidean space. Collinearity but not parallelism is preserved in perspective space and angles are not invariant under translation and rotation. Similar relationships have shown to be properties of visual space. Alley experiments performed early in the nineteenth century have been instrumental in hypothesizing curved visual spaces. Alleys were computed in perspective space and compared with reconstructed alleys of Blumenfeld. Parallel alleys were accurately described by perspective geometry. Accurate distance alleys were derived from parallel alleys by adjusting the interstimulus distances according to the size-distance invariance hypothesis. Agreement between computed and experimental alleys and accommodation of experimental results that rejected Luneburg's model show that perspective space is an appropriate model for how we perceive orientations and angles. The model is also appropriate for perceived distance ratios between stimuli but fails to predict perceived distances.

  17. Acoustic-structure interaction problems. Final report

    SciTech Connect

    Love, E.; Taylor, R.L.

    1993-12-01

    The purpose of this report is to compare and evaluate different numerical methods for solving problems of interaction between elastic solids and acoustic fluids. In particular, we concentrate our efforts on solution techniques involving the finite element method. To that end, in Chapter 2 we discuss different options for analysis of infinite fluids. In particular, the method of mesh trunction and the use of radiation elements and the use of infinite elements are discussed. Also discussed is the analysis of scattering from rigid boundaries. Chapter 3 is a brief discussion of finite element formulations for elastic solids. We review the development, of two dimensional plane strain elements and one dimensional plate and shell elements. In Chapter 4, there is a discussion of the method used to couple the solid and the fluid. We give examples for solution of scattering of pressure waves from thin elastic shell structures. Chapter 5 is a brief conclusion of results and includes recommendations for the best methods of solution and additional research.

  18. Triumph or Triage? The World Food Problem in Geographical Perspective. Resource Paper No. 75-3.

    ERIC Educational Resources Information Center

    Knight, C. Gregory; Wilcox, R. Paul

    Emphasizing a problem-solving perspective, the document investigates the world food scene. Simply defined, the world food problem is the apparent inability of the world's people to feed themselves adequately and consistently. Intended for use by college level geography instructors as they develop courses on human uses of the environment, the…

  19. Problem Behaviour and Psychosocial Functioning in Young Children with Williams Syndrome: Parent and Teacher Perspectives

    ERIC Educational Resources Information Center

    Klein-Tasman, B. P.; Lee, K.

    2017-01-01

    Background: There is sparse literature about problem behaviour in young children with Williams syndrome (WS) and little consideration of the perspectives of multiple respondents. Methods: Problem behaviour of 35 children with WS ages 2 to 6 was examined based on both parent and teacher report using the Achenbach preschool forms. Results: The most…

  20. Problems and Opportunities in School Financial Management: A Consultant's Perspective.

    ERIC Educational Resources Information Center

    Chabotar, Kent John

    1987-01-01

    Summarizes major problems in school financial management and suggests practical improvements to aid external reporting of financial data and internal management. Sections of the article describe these categories of problems: (1) budget presentation; (2) management control; (3) cost accounting; and (4) financial reporting. (PS)

  1. Problem Solving in Technology Education: A Taoist Perspective.

    ERIC Educational Resources Information Center

    Flowers, Jim

    1998-01-01

    Offers a new approach to teaching problem solving in technology education that encourages students to apply problem-solving skills to improving the human condition. Suggests that technology teachers incorporate elements of a Taoist approach in teaching by viewing technology as a tool with a goal of living a harmonious life. (JOW)

  2. Dyscalculia and Other Learning Problems in Arithmetic: A Historical Perspective.

    ERIC Educational Resources Information Center

    Sharma, Mahesh C.

    1986-01-01

    Evidence on learning problems due to dyscalculia is surveyed. Definitions, factors responsible for dyscalculia, split-brain research and hemispheric roles, mathematics learning problems and personality, materials for instruction, and levels of knowing mathematics are among the topics discussed with an extensive list of references. (MNS)

  3. Perspectives of Disciplinary Problems and Practices in Elementary Schools

    ERIC Educational Resources Information Center

    Huger Marsh, Darlene P.

    2012-01-01

    Ill-discipline in public schools predates compulsory education in the United States. Disciplinary policies and laws enacted to combat the problem have met with minimal success. Research and recommendations have generally focused on the indiscipline problems ubiquitous in intermediate, junior and senior high schools. However, similar misbehaviors…

  4. Problem-Based Learning: A Critical Rationalist Perspective

    ERIC Educational Resources Information Center

    Parton, Graham; Bailey, Richard

    2008-01-01

    Although problem-based learning is being adopted by many institutions around the world as an effective model of learning in higher education, there is a surprising lack of critique in the problem-based learning literature in relation to its philosophical characteristics. This paper explores epistemology as a starting point for investigating the…

  5. Problem-Based Learning: A Critical Rationalist Perspective

    ERIC Educational Resources Information Center

    Parton, Graham; Bailey, Richard

    2008-01-01

    Although problem-based learning is being adopted by many institutions around the world as an effective model of learning in higher education, there is a surprising lack of critique in the problem-based learning literature in relation to its philosophical characteristics. This paper explores epistemology as a starting point for investigating the…

  6. Facilitating Flexible Problem Solving: A Cognitive Load Perspective

    ERIC Educational Resources Information Center

    Kalyuga, Slava; Renkl, Alexander; Paas, Fred

    2010-01-01

    The development of flexible, transferable problem-solving skills is an important aim of contemporary educational systems. Since processing limitations of our mind represent a major factor influencing any meaningful learning, the acquisition of flexible problem-solving skills needs to be based on known characteristics of our cognitive architecture…

  7. Dyscalculia and Other Learning Problems in Arithmetic: A Historical Perspective.

    ERIC Educational Resources Information Center

    Sharma, Mahesh C.

    1986-01-01

    Evidence on learning problems due to dyscalculia is surveyed. Definitions, factors responsible for dyscalculia, split-brain research and hemispheric roles, mathematics learning problems and personality, materials for instruction, and levels of knowing mathematics are among the topics discussed with an extensive list of references. (MNS)

  8. Melt Structure and Properties: a Spectroscopic Perspective

    NASA Astrophysics Data System (ADS)

    Stebbins, J.

    2006-12-01

    Entropy, volume, and their P/T derivatives are at the heart of models of the thermodynamics of silicate melts and magmas. Quantitative characterization of glass structure is leading to important new insights into the links from "Microscopic to Macroscopic" that can at least guide interpretations of data and in some cases even have predictive power. A few recent examples will be discussed here. The often-large configurational components to heat capacities, thermal expansivities, and compressibilities of melts strongly indicate that structural changes with temperature and pressure are of key importance. At least some aspects of thermal increases in configurational (as opposed to vibrational) disorder are amenable to spectroscopic detection, either with in situ methods or on glasses with varying quench rates and thus varying fictive temperatures. In some systems, such changes are now clear, and can be shown to make significant contributions to properties. These include network cation coordination in systems such as borate liquids (BO4 to BO3 at higher T), and Al-Si disordering in aluminosilicates. In general, however, progress in this rich problem has only begun. It has long been suspected from thermodynamic analyses (and theoretical simulations) that configurational changes in melts play a key role in volume compression at high pressure, over and above that which can be expressed in "normal" equations of state or from those expected from bond compression and bending. Scattering and spectroscopic studies have revealed some of the important aspects of pressure-induced structural changes, but again we are just at the beginning of full understanding. For example, binary silicate glasses quenched from high-P melts clearly record some systematic increases in Si coordination, while aluminosilicates record systematic pressure and compositional (modifier cation field strength) effects on Al coordination in recovered samples with large, quenched-in density increases

  9. Effects of Exposure to Microwaves: Problems and Perspectives*

    PubMed Central

    Michaelson, Sol M.

    1974-01-01

    During the last 25 years, there has been a remarkable development and increase in the number of processes and devices that utilize or emit microwaves. Such devices are used in all sectors of our society for military, industrial, telecommunications, and consumer applications. Although there is information on biologic effects and potential hazard to man from exposure to microwaves, considerable confusion and misinformation has permeated not only the public press but also some scientific and technical publications. The purpose of this review is to place the available information on biologic effects of microwaves in proper perspective and to suggest approaches to future studies. PMID:4620329

  10. Marital Jealousy: A Structural Exchange Perspective.

    ERIC Educational Resources Information Center

    McDonald, Gerald W.

    Although the experience of jealously is among the most common of experiences in intimate relationships, little theoretical or empirical work has been done from a sociologial perspective to increase our understanding of this aspect of male-female relationships. An investigation of marital jealousy as a sociological rather than a psychological…

  11. 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…

  12. Modelling Ill-Structured Problem Solving with Schema Theory.

    ERIC Educational Resources Information Center

    Nagy, Philip

    This study assesses the ability of schema theory to address ill-structured problems without becoming unwieldy. Prior to addressing the study proper, the paper reviews the literature on memory for complex phenomena, ill-structured problems, expert-novice differences, administration as problem solving, and assessment of complex learning outcomes.…

  13. 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…

  14. Characteristics of Problems for Problem-Based Learning: The Students' Perspective

    ERIC Educational Resources Information Center

    Sockalingam, Nachamma; Schmidt, Henk G.

    2011-01-01

    This study aimed to identify salient problem characteristics perceived by students in problem-based curricula. To this end, reflective essays from biomedical students (N = 34) on characteristics of good problems were text-analyzed. Students identified eleven characteristics, of which they found the extent to which the problem leads to desired…

  15. Child maltreatment, parent alcohol and drug-related problems, polydrug problems, and parenting practices: a test of gender differences and four theoretical perspectives.

    PubMed

    Locke, Thomas F; Newcomb, Michael

    2004-03-01

    The authors tested how adverse childhood experiences (child maltreatment and parent alcohol- and drug-related problems) and adult polydrug use (as a mediator) predict poor parenting in a community sample (237 mothers and 81 fathers). These relationships were framed within several theoretical perspectives, including observational learning, impaired functioning, self-medication, and parentification-pseudomaturity. Structural models revealed that child maltreatment predicted poor parenting practices among mothers. Parent alcohol- and drug-related problems had an indirect detrimental influence on mothers' parenting and practices through self-drug problems. Among fathers, emotional neglect experienced as a child predicted lack of parental warmth more parental neglect, and sexual abuse experienced as a child predicted a rejecting style of parenting.

  16. Information Seeking When Problem Solving: Perspectives of Public Health Professionals.

    PubMed

    Newman, Kristine; Dobbins, Maureen; Yost, Jennifer; Ciliska, Donna

    2017-04-01

    Given the many different types of professionals working in public health and their diverse roles, it is likely that their information needs, information-seeking behaviors, and problem-solving abilities differ. Although public health professionals often work in interdisciplinary teams, few studies have explored their information needs and behaviors within the context of teamwork. This study explored the relationship between Canadian public health professionals' perceptions of their problem-solving abilities and their information-seeking behaviors with a specific focus on the use of evidence in practice settings. It also explored their perceptions of collaborative information seeking and the work contexts in which they sought information. Key Canadian contacts at public health organizations helped recruit study participants through their list-servs. An electronic survey was used to gather data about (a) individual information-seeking behaviors, (b) collaborative information-seeking behaviors, (c) use of evidence in practice environments, (d) perceived problem-solving abilities, and (e) demographic characteristics. Fifty-eight public health professionals were recruited, with different roles and representing most Canadian provinces and one territory. A significant relationship was found between perceived problem-solving abilities and collaborative information-seeking behavior (r = -.44, p < .00, N = 58), but not individual information seeking. The results suggested that when public health professionals take a shared, active approach to problem solving, maintain personal control, and have confidence, they are more likely collaborate with others in seeking information to complete a work task. Administrators of public health organizations should promote collaboration by implementing effective communication and information-seeking strategies, and by providing information resources and retrieval tools. Public health professionals' perceived problem-solving abilities can

  17. A simulation language approach to structural interaction problems

    NASA Technical Reports Server (NTRS)

    Cutchins, M. A.; Purvis, J. W.

    1982-01-01

    Advantages and disadvantages of using simulation languages in solving structural problems are given. Structural and solid mechanics problems which have strong interactions with other disciplines are emphasized. An aeroservoelastic illustration is described with significant interactions between the dynamics of a flexible flight vehicle structure, the aerodynamics to which it is subjected, the dynamic flight equations, and the vehicle's servo-control system.

  18. New Perspectives on Contingency Corps Force Structure

    DTIC Science & Technology

    1992-04-15

    documnent mazy not bd reead f01 open POISIlcAtif 020 it has been deand by te Wrptiflts na mIits Ofcea gov~erntment Mpfcy. NEW PERSPECTIVES ON...would then be feasible without the previous layers of traditional infrastructure.6 Airborne, air-assault, mechanized , armor, or light infantry...responsibility (AOR) within the past two years. Force projection offers our President an effective instrument of national power. The recent successes by these

  19. Structural Learning Theory: Current Status and New Perspectives.

    ERIC Educational Resources Information Center

    Scandura, Joseph M.

    2001-01-01

    Presents the current status and new perspectives on the Structured Learning Theory (SLT), with special consideration given to how SLT has been influenced by recent research in software engineering. Topics include theoretical constructs; content domains; structural analysis; cognition; assessing behavior potential; and teaching and learning issues,…

  20. Adolescent Health Problems: Behavioral Perspectives. Advances in Pediatric Psychology.

    ERIC Educational Resources Information Center

    Wallander, Jan L., Ed.; Siegel, Lawrence J., Ed.

    This book examines the relationship between adolescent risk-taking behaviors and health. The health-related problems of adolescents frequently are manifestations of social, economic, or behavioral factors. Following an overview (Siegal), the chapters in the first section of the book explore general and conceptual issues: (1) "Epidemiology of…

  1. A Historical Perspective on Problems in Botany Teaching.

    ERIC Educational Resources Information Center

    Hershey, David R.

    1996-01-01

    Discusses how the many problems in botany teaching are interrelated and most have existed since at least the early 1900s. Considers botany teaching at both the precollege and introductory college levels. Discusses botany neglect in biology teaching, botanical illiteracy, uninteresting or irrelevant botany teaching, zoochauvinism, research…

  2. A Neuropsychological Perspective on Attention Problems in Neurofibromatosis Type 1

    ERIC Educational Resources Information Center

    Templer, Alexandra K.; Titus, Jeffrey B.; Gutmann, David H.

    2013-01-01

    Cognitive problems are common in children with neurofibromatosis type 1 and they can often complicate treatment. The current literature review examines cognitive functioning in neurofibromatosis type 1, with a specific focus on executive functioning. This includes exploration of how deficits in executive functioning are expressed in children with…

  3. Constructive field theory and applications: Perspectives and open problems

    NASA Astrophysics Data System (ADS)

    Rivasseau, V.

    2000-06-01

    In this paper we review many interesting open problems in mathematical physics which may be attacked with the help of tools from constructive field theory. They could give work for future mathematical physicists trained with constructive methods well into the 21st century.

  4. A Neuropsychological Perspective on Attention Problems in Neurofibromatosis Type 1

    ERIC Educational Resources Information Center

    Templer, Alexandra K.; Titus, Jeffrey B.; Gutmann, David H.

    2013-01-01

    Cognitive problems are common in children with neurofibromatosis type 1 and they can often complicate treatment. The current literature review examines cognitive functioning in neurofibromatosis type 1, with a specific focus on executive functioning. This includes exploration of how deficits in executive functioning are expressed in children with…

  5. How Problem Solving Can Develop an Algebraic Perspective of Mathematics

    ERIC Educational Resources Information Center

    Windsor, Will

    2011-01-01

    SProblem solving has a long and successful history in mathematics education and is valued by many teachers as a way to engage and facilitate learning within their classrooms. The potential benefit for using problem solving in the development of algebraic thinking is that "it may broaden and develop students' mathematical thinking beyond the…

  6. The Problem of Underqualified Teachers: A Sociological Perspective

    ERIC Educational Resources Information Center

    Ingersoll, Richard M.

    2005-01-01

    Few educational problems have received more attention than has the failure to ensure that the nation's classrooms are staffed by qualified teachers. Many states have pushed for more-rigorous preservice teacher education, training, and certification standards. Moreover, a host of recruitment initiatives have attempted to increase the supply of…

  7. Adolescent Health Problems: Behavioral Perspectives. Advances in Pediatric Psychology.

    ERIC Educational Resources Information Center

    Wallander, Jan L., Ed.; Siegel, Lawrence J., Ed.

    This book examines the relationship between adolescent risk-taking behaviors and health. The health-related problems of adolescents frequently are manifestations of social, economic, or behavioral factors. Following an overview (Siegal), the chapters in the first section of the book explore general and conceptual issues: (1) "Epidemiology of…

  8. Perspectives of mothers with substance use problems on father involvement.

    PubMed

    Gearing, Robin E; Selkirk, Enid K; Koren, Gideon; Leslie, Margaret; Motz, Mary; Zelazo, Laurel B; McNeill, Ted; Lozier, Fernand A

    2008-01-01

    A number of complex factors contribute to pregnant and parenting women's alcohol and substance use. To date, little research has focused on the implications, meaning and experiences of father involvement on mothers with substance use problems. The current study explores the experiences of mothers with substance use problems with respect to the role, impact and meaning of father involvement. This study conducted two focus groups utilizing a phenomenological approach. Mothers receiving clinical services at a comprehensive, community based program serving pregnant and parenting women with substance use problems were recruited to participate in this research. The meaning of father involvement among this group of women centered on four dimensions: emotional support, financial contributions to the family, amount and quality of time spent with the children and the family, and was dependent upon the particular expectations of the mother involved. Barriers and influences of father involvement were identified. The nature of father involvement had negative and positive impacts on participants. Maternal use of alcohol is a complex issue, one factor often ignored in father involvement. For mothers with substance use problems father involvement has a number of implications, both positive and negative.

  9. A Historical Perspective on Problems in Botany Teaching.

    ERIC Educational Resources Information Center

    Hershey, David R.

    1996-01-01

    Discusses how the many problems in botany teaching are interrelated and most have existed since at least the early 1900s. Considers botany teaching at both the precollege and introductory college levels. Discusses botany neglect in biology teaching, botanical illiteracy, uninteresting or irrelevant botany teaching, zoochauvinism, research…

  10. The High School Dropout Problem: Perspectives of Teachers and Principals

    ERIC Educational Resources Information Center

    Bridgeland, John M.; Dilulio, John J., Jr.; Balfanz, Robert

    2009-01-01

    To better understand the views of teachers and administrators on the high school dropout problem, focus groups and nationally representative surveys were conducted of high school teachers and principals. A focus group of superintendents and school board members was also included. To help interpret the results, the authors convened a colloquium…

  11. South Asian and Middle Eastern patients' perspectives on medicine-related problems in the United Kingdom.

    PubMed

    Alhomoud, Faten; Dhillon, Soraya; Aslanpour, Zoe; Smith, Felicity

    2015-08-01

    There has been little research which specifically examines medicine use among South Asian (SA) and Middle Eastern (ME) groups, although evidence suggests that medicine-related needs may be poorly met for these groups. To describe medicine-related problems (MRPs) experienced by SA and ME patients from their perspectives and identify possible contributory factors that may be specific to their cultures. The data were collected in seven pharmacies in London, United Kingdom (UK). The study was a qualitative study. Patients were from SA and ME origins, aged over 18 and prescribed three or more regular medicines. Patients were identified when presenting with a prescription. The data were collected in 80 face-to-face semi-structured interviews using Gordon's MRPs tool. Interviews were audiotaped, transcribed verbatim and analysed thematically using Gordon's coding frame and Nvivo 10 software. Describing MRPs experienced by SA and ME patients from their perspectives and identifying possible contributory factors that may be specific to their cultures. Results Eighty participants (61 % male) had mean (SD) age 58 (13.4) years and a mean (SD) of 8 (4) medicines. Interviews revealed that several factors contributed to the development of MRPs; some appeared to be specific to SA and ME cultures and others were similar to the general population. The factors that were reported to be specific to SA and ME groups comprised religious practices and beliefs, use of non-prescription medicines, extent of family support, and travelling abroad--to patient's homeland or to take religious journeys. Illiteracy, language and communication barriers, lack of translated resources, perceptions of healthcare providers, and difficulty consulting a doctor of the same gender may also contribute to the problems. Many of these factors could be expected to influence patient's safety, adherence, and informed decision-making. This study demonstrated that SA and ME patients have their own problems and needs

  12. Discovering the structure of mathematical problem solving.

    PubMed

    Anderson, John R; Lee, Hee Seung; Fincham, Jon M

    2014-08-15

    The goal of this research is to discover the stages of mathematical problem solving, the factors that influence the duration of these stages, and how these stages are related to the learning of a new mathematical competence. Using a combination of multivariate pattern analysis (MVPA) and hidden Markov models (HMM), we found that participants went through 5 major phases in solving a class of problems: A Define Phase where they identified the problem to be solved, an Encode Phase where they encoded the needed information, a Compute Phase where they performed the necessary arithmetic calculations, a Transform Phase where they performed any mathematical transformations, and a Respond Phase where they entered an answer. The Define Phase is characterized by activity in visual attention and default network regions, the Encode Phase by activity in visual regions, the Compute Phase by activity in regions active in mathematical tasks, the Transform Phase by activity in mathematical and response regions, and the Respond phase by activity in motor regions. The duration of the Compute and Transform Phases were the only ones that varied with condition. Two features distinguished the mastery trials on which participants came to understand a new problem type. First, the duration of late phases of the problem solution increased. Second, there was increased activation in the rostrolateral prefrontal cortex (RLPFC) and angular gyrus (AG), regions associated with metacognition. This indicates the importance of reflection to successful learning. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Perspective on Microfluidic Cell Separation: A Solved Problem?

    PubMed Central

    2015-01-01

    The purification and sorting of cells using microfluidic methodologies has been a remarkably active area of research over the past decade. Much of the scientific and technological work associated with microfluidic cell separation has been driven by needs in clinical diagnostics and therapeutic monitoring, most notably in the context of circulating tumor cells. The last several years have seen advances in a broad range of separation modalities ranging from miniaturized analogs of established techniques such as fluorescence- and magnetic-activated cell sorting (FACS and MACS, respectively), to more specialized approaches based on affinity, dielectrophoretic mobility, and inertial properties of cells. With several of these technologies nearing commercialization, there is a sense that the field of microfluidic cell separation has achieved a high level of maturity over an unusually short span of time. In this Perspective, we set the stage by describing major scientific and technological advances in this field and ask what the future holds. While many scientific questions remain unanswered and new compelling questions will undoubtedly arise, the relative maturity of this field poses some unique challenges. PMID:25350696

  14. Protein aggregate spreading in neurodegenerative diseases: Problems and perspectives

    PubMed Central

    Lee, Seung-Jae; Lim, Hee-Sun; Masliah, Eliezer; Lee, He-Jin

    2014-01-01

    Progressive accumulation of specific protein aggregates is a defining feature of many major neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, fronto-temporal dementia, Huntington’s disease, and Creutzfeldt–Jakob disease (CJD). Findings from several recent studies have suggested that aggregation-prone proteins, such as tau, α-synuclein, polyglutamine-containing proteins, and amyloid-β, can spread to other cells and brain regions, a phenomenon considered unique to prion disorders, such as CJD and bovine spongiform encephalopathy. Cell-to-cell propagation of protein aggregates may be the general underlying principle for progressive deterioration of neurodegenerative diseases. This may also have significant implications in cell replacement therapies, as evidenced by the propagation of α-synuclein aggregates from host to grafted cells in long-term transplants in Parkinson’s patients. Here, we review recent progress in protein aggregate propagation in experimental model systems and discuss outstanding questions and future perspectives. Understanding the mechanisms of this pathological spreading may open the way to unique opportunities for development of diagnostic techniques and novel therapies for protein misfolding-associated neurodegenerative diseases. PMID:21624403

  15. [New perspectives for an old problem: premature labor].

    PubMed

    Barrón Vallejo, J; Kably Ambe, A; Limón Luque, L; Barroso Villa, G; Jurado Jurado, M; Blank Goldenberg, C

    1997-08-01

    Preterm birth has been and continues to be one of the most serious problems in Obstetrics. It is the most common cause of neonatal death, and morbidity in surviving infants. The presence of bacterial vaginosis, and other genital infections is associated with increased risk of preterm labor. Cytokines promote the release of prostaglandin, and have been implicated as cause of uterina activity. Recently, new methods of detection as transvaginal ultrasonography, and measures of cervical fetal fibronectin have been acclaimed as useful to detect the problem. Atosiban, cytokines, glyceril trinitrate, and many others agents have been proposed as treatments and are under investigation. Such drugs, will allow an effective management of preterm labor with lower side effects. Antenatal TRH administration cannot be recommended for widespread clinical use. However, the antenatal administration of corticosteroids to fetuses at risk of preterm delivery include not only a reduction in the risk of respiratory distress syndrome but also a significative reduction in intraventricular hemorrhage mortality.

  16. Searching for hard instances of CVP problem-cryptographic perspective

    NASA Astrophysics Data System (ADS)

    Pardyak, Jacek

    2008-01-01

    Lattice is regular arrangement of points in R n. The Closest Vector Problem (CVP) is defined as follow: given a point y in Rn and a lattice basis B find lattice vector Bx closest to y . The CVP problem is believed to be computationally intractable in average. Here we propose a new way to generate hard instances of CVP and a method that allows us to construct a cryptographic trapdoor function based on it. We start with brief introduction to lattices. Next we present a very natural application of lattices in cryptography, i.e. GGH cryptosystem and the way the system was broken. Finally we present our modifications way to generate hard instances of CVP, harder than previously proposed in GGH.

  17. Conceptual Structures in Mathematical Problem Solving.

    ERIC Educational Resources Information Center

    Cifarelli, Victor

    The processes by which conceptual knowledge is constructed during mathematical problem solving were studied, focusing on the cognitive activity of learners (i.e., the ways they elaborate, reorganize, and reconceptualize their solution activity). Underlying this research is the view that learners' mathematical conceptions evolve from their activity…

  18. On some structure-turbulence interaction problems

    NASA Technical Reports Server (NTRS)

    Maekawa, S.; Lin, Y. K.

    1976-01-01

    The interactions between a turbulent flow structure; responding to its excitation were studied. The turbulence was typical of those associated with a boundary layer, having a cross-spectral density indicative of convection and statistical decay. A number of structural models were considered. Among the one-dimensional models were an unsupported infinite beam and a periodically supported infinite beam. The fuselage construction of an aircraft was then considered. For the two-dimensional case a simple membrane was used to illustrate the type of formulation applicable to most two-dimensional structures. Both the one-dimensional and two-dimensional structures studied were backed by a cavity filled with an initially quiescent fluid to simulate the acoustic environment when the structure forms one side of a cabin of a sea vessel or aircraft.

  19. Preventive Intervention for Early Childhood Behavioral Problems: An Ecological Perspective

    PubMed Central

    Shepard, Stephanie A.; Dickstein, Susan

    2009-01-01

    The purpose of this paper is to highlight the importance of preventive interventions targeting parents when addressing early childhood behavior problems. We briefly review evidence-based parent management training programs (PMT), focusing on one particular program, the Incredible Years Series (IY). Next, we discuss the barriers to embedding evidence-based practice like IY in community contexts, and demonstrate how early childhood mental health consultation can be used to enhance community capacity to adopt evidence-based practice and improve outcomes for the large number of young children and their families in need. PMID:19486845

  20. JOSPT Perspectives for Patients. Concussions: an underdiagnosed problem for athletes?

    PubMed

    2012-07-01

    Ignoring symptoms of a concussion and continuing to play after receiving a blow or jolt to the head can be dangerous, make symptoms worse, and delay recovery. Repeated concussions can lead to a longer recovery and may result in long-term problems. Screening tools include checklists of symptoms or quick tests that can help detect a concussion. A study published in the July 2012 issue of used these screening tools to measure changes in player function both before and after a football season.

  1. Pericytes: developmental, physiological, and pathological perspectives, problems, and promises.

    PubMed

    Armulik, Annika; Genové, Guillem; Betsholtz, Christer

    2011-08-16

    Pericytes, the mural cells of blood microvessels, have recently come into focus as regulators of vascular morphogenesis and function during development, cardiovascular homeostasis, and disease. Pericytes are implicated in the development of diabetic retinopathy and tissue fibrosis, and they are potential stromal targets for cancer therapy. Some pericytes are probably mesenchymal stem or progenitor cells, which give rise to adipocytes, cartilage, bone, and muscle. However, there is still confusion about the identity, ontogeny, and progeny of pericytes. Here, we review the history of these investigations, indicate emerging concepts, and point out problems and promise in the field of pericyte biology. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. [Current status of lung transplantation in China: problems and perspectives].

    PubMed

    Wang, X A; Jiang, G N

    2016-12-01

    Despite rapid progress, clinical lung transplantation in China still lags far behind. A great challenge remains in donor lung utilization and perioperative medicine. It's really abnormal that we are so backward in lung transplantation when we have come up with the advanced world levels in thoracic surgery, pulmonology and critical care medicine. Our shortcomings were analyzed by comparing lung transplantation in China and in the advanced countries. The first problem is multidisciplinary teamwork. In the United States, a lung transplant team includes physician specialized in lung transplantation, thoracic surgeons, nurses, respiratory therapists and other specialists possibly needed. In contrast, our lung transplant teams are derived from thoracic surgery teams. Other specialists are invited for consultation just when thoracic surgeons are unable to deal with the tough issues in perioperative medicine. The low utilization and quality of donor lung also result from poor teamwork. The second problem is that we failed to integrate such advances as extra corporeal lung support and ex vivo lung perfusion into our lung transplant programs. In conclusion, the development of lung transplantation in China is dependent upon an initiative, multidisciplinary team approach.

  3. Bioinformatics education dissemination with an evolutionary problem solving perspective.

    PubMed

    Jungck, John R; Donovan, Samuel S; Weisstein, Anton E; Khiripet, Noppadon; Everse, Stephen J

    2010-11-01

    Bioinformatics is central to biology education in the 21st century. With the generation of terabytes of data per day, the application of computer-based tools to stored and distributed data is fundamentally changing research and its application to problems in medicine, agriculture, conservation and forensics. In light of this 'information revolution,' undergraduate biology curricula must be redesigned to prepare the next generation of informed citizens as well as those who will pursue careers in the life sciences. The BEDROCK initiative (Bioinformatics Education Dissemination: Reaching Out, Connecting and Knitting together) has fostered an international community of bioinformatics educators. The initiative's goals are to: (i) Identify and support faculty who can take leadership roles in bioinformatics education; (ii) Highlight and distribute innovative approaches to incorporating evolutionary bioinformatics data and techniques throughout undergraduate education; (iii) Establish mechanisms for the broad dissemination of bioinformatics resource materials and teaching models; (iv) Emphasize phylogenetic thinking and problem solving; and (v) Develop and publish new software tools to help students develop and test evolutionary hypotheses. Since 2002, BEDROCK has offered more than 50 faculty workshops around the world, published many resources and supported an environment for developing and sharing bioinformatics education approaches. The BEDROCK initiative builds on the established pedagogical philosophy and academic community of the BioQUEST Curriculum Consortium to assemble the diverse intellectual and human resources required to sustain an international reform effort in undergraduate bioinformatics education.

  4. Ecocultural Perspective in Learning Disability: Family Support Resources, Values, Child Problem Behaviors

    ERIC Educational Resources Information Center

    Cen, Suzan; Aytac, Berna

    2017-01-01

    The present study aimed to assess the interaction between familial and cultural factors on child problem behaviors of learning disabled children aged between 7 and 14 within the perspective of ecocultural theory (N = 90). Mothers completed the Family Support Scale, Portrait Values Questionnaire, and Social-Demographical Form, and teachers…

  5. Using Ontological Engineering to Overcome AI-ED Problems: Contribution, Impact and Perspectives

    ERIC Educational Resources Information Center

    Mizoguchi, Riichiro; Bourdeau, Jacqueline

    2016-01-01

    This article reflects on the ontology engineering methodology discussed by the paper entitled "Using Ontological Engineering to Overcome AI-ED Problems" published in this journal in 2000. We discuss the achievements obtained in the last 10 years, the impact of our work as well as recent trends and perspectives in ontology engineering for…

  6. The Problems of "Competence" and Alternatives from the Scandinavian Perspective of "Bildung"

    ERIC Educational Resources Information Center

    Willbergh, Ilmi

    2015-01-01

    The paper aims to show how competence as an educational concept for the 21st century is struggling with theoretical problems for which the concept of "Bildung" in the European tradition can offer alternatives, and to discuss the possibility of developing a sustainable educational concept from the perspectives of competence and…

  7. Inclusion Strategies for Students with Learning and Behavior Problems: Perspectives, Experiences, and Best Practices.

    ERIC Educational Resources Information Center

    Zionts, Paul, Ed.

    This book presents discussions of the practical implementation of inclusion principles with students having learning and/or behavioral problems and disorders. The chapters, arranged under two topical units, "Perspectives and Experiences" and "Best Practices" are: (1) "Inclusion: Chasing the Impossible Dream? Maybe"…

  8. The Problems of "Competence" and Alternatives from the Scandinavian Perspective of "Bildung"

    ERIC Educational Resources Information Center

    Willbergh, Ilmi

    2015-01-01

    The paper aims to show how competence as an educational concept for the 21st century is struggling with theoretical problems for which the concept of "Bildung" in the European tradition can offer alternatives, and to discuss the possibility of developing a sustainable educational concept from the perspectives of competence and…

  9. Learner Perspectives of Online Problem-Based Learning and Applications from Cognitive Load Theory

    ERIC Educational Resources Information Center

    Chen, Ruth

    2016-01-01

    Problem-based learning (PBL) courses have historically been situated in physical classrooms involving in-person interactions. As online learning is embraced in higher education, programs that use PBL can integrate online platforms to support curriculum delivery and facilitate student engagement. This report describes student perspectives of the…

  10. Problem-Based Learning in a Physical Therapy Program and Subsequent Clinical Practice: The Practitioners' Perspectives.

    ERIC Educational Resources Information Center

    Wilson, Stanley H.; Gallagher, Jo D.; Elbaum, Leonard; Smith, Douglas H.

    This study examined the perspectives of three graduates of a problem-based learning (PBL) physical therapy (PT) program about their clinical practice. Researchers used qualitative methods of observation, interview, and journaling to gather the data. Three sessions of audiotaped interviews and two observation sessions were conducted with the three…

  11. Learner Perspectives of Online Problem-Based Learning and Applications from Cognitive Load Theory

    ERIC Educational Resources Information Center

    Chen, Ruth

    2016-01-01

    Problem-based learning (PBL) courses have historically been situated in physical classrooms involving in-person interactions. As online learning is embraced in higher education, programs that use PBL can integrate online platforms to support curriculum delivery and facilitate student engagement. This report describes student perspectives of the…

  12. Using Ontological Engineering to Overcome AI-ED Problems: Contribution, Impact and Perspectives

    ERIC Educational Resources Information Center

    Mizoguchi, Riichiro; Bourdeau, Jacqueline

    2016-01-01

    This article reflects on the ontology engineering methodology discussed by the paper entitled "Using Ontological Engineering to Overcome AI-ED Problems" published in this journal in 2000. We discuss the achievements obtained in the last 10 years, the impact of our work as well as recent trends and perspectives in ontology engineering for…

  13. Inclusion Strategies for Students with Learning and Behavior Problems: Perspectives, Experiences, and Best Practices.

    ERIC Educational Resources Information Center

    Zionts, Paul, Ed.

    This book presents discussions of the practical implementation of inclusion principles with students having learning and/or behavioral problems and disorders. The chapters, arranged under two topical units, "Perspectives and Experiences" and "Best Practices" are: (1) "Inclusion: Chasing the Impossible Dream? Maybe"…

  14. International Perspectives on Problem-Based Learning: Contexts, Cultures, Challenges, and Adaptations

    ERIC Educational Resources Information Center

    Hmelo-Silver, Cindy E.

    2012-01-01

    The theme of this special issue is timely as the world becomes increasingly flat and globally connected (Friedman, 2007). By focusing on an international perspective in problem-based learning (PBL), it puts culture squarely in the center, whether it is a national or disciplinary culture. The articles in this special issue represent Thailand, South…

  15. International Perspectives on Problem-Based Learning: Contexts, Cultures, Challenges, and Adaptations

    ERIC Educational Resources Information Center

    Hmelo-Silver, Cindy E.

    2012-01-01

    The theme of this special issue is timely as the world becomes increasingly flat and globally connected (Friedman, 2007). By focusing on an international perspective in problem-based learning (PBL), it puts culture squarely in the center, whether it is a national or disciplinary culture. The articles in this special issue represent Thailand, South…

  16. Developing My Perspectives on Scaffolding and Problem-Based Learning: A Retrospective View

    ERIC Educational Resources Information Center

    Belland, Brian R.

    2016-01-01

    In this paper, I describe the iterative development of my perspectives on scaffolding and problem-based learning through interactions with other scholars and research. Such influences include doctoral experiences, funded projects, and exposures to research from a variety of traditions.

  17. Heuristic Research: A New Perspective on Ethics and Problems in Adult Education Research.

    ERIC Educational Resources Information Center

    Beckstrom, Edward S.

    1993-01-01

    Heuristic research is a highly autobiographical investigation of one's experience with a question or problem. This article examines the basic concepts and processes of heuristic research (in adult education), including self-dialog, tacit knowing, inverted perspective, intuition, indwelling, and focusing. Heuristic research design phases involve…

  18. Unsolved problems and future perspectives of hepatitis B virus vaccination.

    PubMed

    Tajiri, Kazuto; Shimizu, Yukihiro

    2015-06-21

    Hepatitis B virus (HBV) infection is still a serious worldwide problem, and vaccination is the most effective strategy for primary prevention of the infection. Although universal vaccination may be required for total eradication, several countries, including Japan, have not yet adopted universal vaccination programs. Some individuals are non-responders to HBV vaccine and several mechanisms responsible for their poor response have been proposed. To overcome non-response, third generation vaccines with pre-S proteins have been developed. These vaccines have shown better anti-HBs responses and may also be effective in preventing infection by HBV with S mutant. Improvement of vaccine efficacy by intradermal administration, or co-administration with cytokines or adjuvants, may also be effective in non-responders. The necessity, timing and method of booster vaccination in responders with decreased anti-HBs responses, and effective vaccination against S-mutant HBV, are issues requiring resolution in the global prevention of HBV infection.

  19. Problem-based learning in medical school: A student's perspective.

    PubMed

    Chang, Bliss J

    2016-12-01

    Problem-based learning (PBL) has been a concept in existence for decades yet its implementation in medical student education is limited. Considering the nature of a physician's work, PBL is a logical step towards developing students' abilities to synthesize and integrate foundational concepts into clinical medicine. Harvard's recently redesigned Pathways curriculum has shifted almost exclusively towards PBL in its one-year preclinical curriculum. This piece provides my thoughts, both derived from my own reflections as well as conversations and observations of my peers, on the effectiveness, advantages, and disadvantages of a PBL curriculum. All in all, the feelings of my peers and I regarding PBL has been overwhelmingly positive despite potential areas of improvement and continued fine-tuning.

  20. Unsolved problems and future perspectives of hepatitis B virus vaccination

    PubMed Central

    Tajiri, Kazuto; Shimizu, Yukihiro

    2015-01-01

    Hepatitis B virus (HBV) infection is still a serious worldwide problem, and vaccination is the most effective strategy for primary prevention of the infection. Although universal vaccination may be required for total eradication, several countries, including Japan, have not yet adopted universal vaccination programs. Some individuals are non-responders to HBV vaccine and several mechanisms responsible for their poor response have been proposed. To overcome non-response, third generation vaccines with pre-S proteins have been developed. These vaccines have shown better anti-HBs responses and may also be effective in preventing infection by HBV with S mutant. Improvement of vaccine efficacy by intradermal administration, or co-administration with cytokines or adjuvants, may also be effective in non-responders. The necessity, timing and method of booster vaccination in responders with decreased anti-HBs responses, and effective vaccination against S-mutant HBV, are issues requiring resolution in the global prevention of HBV infection. PMID:26109794

  1. Van der Waals Perspective on Coarse-Graining: Progress toward Solving Representability and Transferability Problems.

    PubMed

    Dunn, Nicholas J H; Foley, Thomas T; Noid, William G

    2016-12-20

    -relationship of representability and transferability problems. Both arise as consequences of transferring thermodynamic information from the high resolution configuration space and encoding this information into the many-body potential of mean force (PMF), that is, the potential that emerges from an exact coarse-graining procedure. At least in principle, both representability and transferability problems can be resolved by properly addressing this thermodynamic information. In particular, we have demonstrated that "pressure-matching" provides a practical and rigorous means for addressing the density dependence of the PMF. The resulting bottom-up models accurately reproduce the structure, equilibrium density, compressibility, and pressure equation of state for AA models of molecular liquids. Additionally, we have extended this approach to develop transferable potentials that provide similar accuracy for heptane-toluene mixtures. Moreover, these potentials provide predictive accuracy for modeling concentrations that were not considered in their parametrization. More generally, this work suggests a "van der Waals" perspective on coarse-graining, in which conventional structure-based methods accurately describe the configuration dependence of the PMF, while independent variational principles infer the thermodynamic information that is necessary to resolve representability and transferability problems.

  2. Structured Collaboration versus Individual Learning in Solving Physics Problems

    ERIC Educational Resources Information Center

    Harskamp, Egbert; Ding, Ning

    2006-01-01

    The research issue in this study is how to structure collaborative learning so that it improves solving physics problems more than individual learning. Structured collaborative learning has been compared with individual learning environments with Schoenfeld's problem-solving episodes. Students took a pre-test and a post-test and had the…

  3. Interface Problems: Structural Constraints on Interpretation?

    ERIC Educational Resources Information Center

    Frazier, Lyn; Clifton, Charles; Rayner, Keith; Deevy, Patricia; Koh, Sungryong; Bader, Markus

    2005-01-01

    Five experiments investigated the interpretation of quantified noun phrases in relation to discourse structure. They demonstrated, using questionnaire and on-line reading techniques, that readers in English prefer to give a quantified noun phrase in (VP-external) subject position a presuppositional interpretation, in which the noun phrase limits…

  4. Interface Problems: Structural Constraints on Interpretation?

    ERIC Educational Resources Information Center

    Frazier, Lyn; Clifton, Charles; Rayner, Keith; Deevy, Patricia; Koh, Sungryong; Bader, Markus

    2005-01-01

    Five experiments investigated the interpretation of quantified noun phrases in relation to discourse structure. They demonstrated, using questionnaire and on-line reading techniques, that readers in English prefer to give a quantified noun phrase in (VP-external) subject position a presuppositional interpretation, in which the noun phrase limits…

  5. [Health system in Afghanistan: problems and institutional perspectives].

    PubMed

    Lejars, M

    2008-10-01

    Afghanistan has been ravaged by years of conflict. To provide emergency services and restore access health services, the Public Health Ministry with the assistance of partners developed first a package of basic health services delivered by NGO contractors and second a package of essential hospital services. The Ministry's role consists of providing guidance. To reduce the many issues and problems affecting this role, reforms are now being undertaken and a new national health care strategy is being developed within the framework of the National Development Strategy. An institution-building project has been initiated with European Union funding to allow the Health Ministry to carry out its stewardship and management functions with greater effectiveness and transparency. This project is essential for the successful outcome of all future strategies and programs planned by the Health Ministry to enhance its institutional effectiveness. The objectives of this project are to strengthen planning and auditing activities, promote quality assurance, implement funding mechanisms for health-related activities, organize management of human resources, maintain ongoing efforts to reform the administration and fight against corruption, and lay the foundations for managing finances and procurement. The scope of this project underlines the importance of its outcome. However the institution-building process will be long and constantly threatened by political instability and insecurity.

  6. Problem based learning in midwifery--the students' perspective.

    PubMed

    Rowan, Catherine J; McCourt, Christine; Beake, Sarah

    2008-01-01

    Problem based learning (PBL) has been adopted in many settings for the education of health professionals. It has generally been evaluated well by students although much of the literature comes from medical education. The aim of this study was to ascertain the views of student midwives at the beginning and at the end of their programme and three months after graduation about the use of a PBL based programme in midwifery. Eight focus groups were conducted with students whilst undertaking a PBL programme from both a shortened and three year programme across two sites. A questionnaire was sent 3 months after graduation to midwives who had completed the programme. Key themes which emerged from this study were that although students gained skills in information retrieval and critique some did not always feel well prepared for practice. The focus on individual presentations in the tutorial tended to be interpreted as performance rather than discussion in a spirit of enquiry. Students reported being particularly anxious at the beginning of their programme about their learning. They felt that their experience was dependent upon the participation and motivation of the group members.

  7. Cathodic protection of offshore structures - Problems and solutions

    SciTech Connect

    Robson, D.N.C.

    1985-01-01

    The paper outlines the three basic options for cathodically protecting offshore structures; namely impressed current or sacrificial anodes protecting a bare metal structure or sacrificial anodes on a totally painted structure. Some of the problems encountered by these systems are described and some specific examples experienced by Britiol structures are discussed in more detail. Various solutions for overcoming these problems are discussed and comparisons made of their respective costs and ease of implementation. Finally, some solution to CP problems adopted by Britoil are described with emphasis on the difficulties in implementation.

  8. Solving Fluid Structure Interaction Problems with an Immersed Boundary Method

    NASA Technical Reports Server (NTRS)

    Barad, Michael F.; Brehm, Christoph; Kiris, Cetin C.

    2016-01-01

    An immersed boundary method for the compressible Navier-Stokes equations can be used for moving boundary problems as well as fully coupled fluid-structure interaction is presented. The underlying Cartesian immersed boundary method of the Launch Ascent and Vehicle Aerodynamics (LAVA) framework, based on the locally stabilized immersed boundary method previously presented by the authors, is extended to account for unsteady boundary motion and coupled to linear and geometrically nonlinear structural finite element solvers. The approach is validated for moving boundary problems with prescribed body motion and fully coupled fluid structure interaction problems. Keywords: Immersed Boundary Method, Higher-Order Finite Difference Method, Fluid Structure Interaction.

  9. Complex II from a structural perspective.

    PubMed

    Horsefield, Rob; Iwata, So; Byrne, Bernadette

    2004-04-01

    The super-macromolecular complex, succinate:quinone oxidoreductase (SQR, Complex II, succinate dehydrogenase) couples the oxidation of succinate in the matrix / cytoplasm to the reduction of quinone in the membrane. This function directly connects the Krebs cycle and the aerobic respiratory chain. Until the recent first report of the structure of SQR from Escherichia coli (E. coli) the structure-function relationships in SQR have been inferred from the structures of the homologous QFR, which catalyses the same reaction in the opposite direction. The structure of SQR from E. coli, analogous to the mitochondrial respiratory Complex II, has provided new insight into SQR's molecular design and mechanism, revealing the electron transport pathway through the enzyme. Comparison of the structures of SQR, QFR and other related flavoproteins shows how common amino acid residues at the interface of two domains facilitate the inter-conversion of succinate and fumarate. Additionally, the structure has provided a possible explanation as to why certain organisms utilise both SQR and QFR despite the fact that both can catalyse the inter-conversion of succinate and fumarate, in vitro and in vivo. Here we review how this structure has advanced our knowledge of this important enzyme and compare the structural information to other members of the Complex II superfamily and related flavoproteins.

  10. Exploring Hearing Aid Problems: Perspectives of Hearing Aid Owners and Clinicians.

    PubMed

    Bennett, Rebecca J; Laplante-Lévesque, Ariane; Meyer, Carly J; Eikelboom, Robert H

    2017-08-03

    To gather perspectives of hearing aid owners and hearing healthcare clinicians with regard to problems that arise after hearing aid fitting and use these perspectives to generate a conceptual framework to gain a better understanding of these problems. Participants included a group of 17 hearing aid owners and a group of 21 hearing healthcare clinicians; data collection occurred separately for each group. Participants each attended two group sessions in Perth, Western Australia, wherein they: (1) generated statements describing the problems associated with hearing aids and (2) grouped and rated the statements to identify key themes. Concept mapping was used to generate a conceptual framework. Participants identified four concepts regarding hearing aid problems as follows: (1) hearing aid management; (2) hearing aid sound quality and performance; (3) feelings, thoughts, and behaviors; and (4) information and training. While hearing aid owners and clinicians generated similar results regarding the concepts derived, the clinicians reported that the problems identified had a greater negative impact on hearing aid success than did hearing aid owners. The magnitude and diversity of hearing aid problems identified in this study highlight the ongoing challenges that hearing aid owners face and suggest that current processes for hearing aid fitting can be improved. Problems relating to hearing aid management were most often deemed to have the greatest impact on hearing aid success and be the most preventable/solvable, and thus are a good starting point when addressing hearing aid-related problems.

  11. Structural Learning Theory: Current Status and New Perspectives.

    ERIC Educational Resources Information Center

    Scandura, Joseph M.

    This paper discusses the current status of and new perspectives on the Structural Learning Theory (SLT). Special consideration is given to how SLT has been influenced by recent research in software engineering, and the range of possibilities it opens for instructional research and practice in the 21st century. Starting with fundamental precepts of…

  12. Perspective view. Fivestory reinforced concrete factory building reveals the structural ...

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

    Perspective view. Five-story reinforced concrete factory building reveals the structural frame on the exterior of the facade. Twelve bay facade facing onto Clay Avenue (north facade) has first floor openings bricked up. Mix of typical factory windows and glass block windows fill the majority of the openings on the rest of building - Russell Industrial Center, 1600 Clay Avenue, Detroit, MI

  13. Dissipative structures, machines, and organisms: A perspective

    NASA Astrophysics Data System (ADS)

    Kondepudi, Dilip; Kay, Bruce; Dixon, James

    2017-10-01

    Self-organization in nonequilibrium systems resulting in the formation of dissipative structures has been studied in a variety of systems, most prominently in chemical systems. We present a study of a voltage-driven dissipative structure consisting of conducting beads immersed in a viscous medium of oil. In this simple system, we observed remarkably complex organism-like behavior. The dissipative structure consists of a tree structure that spontaneously forms and moves like a worm and exhibits many features characteristic of living organisms. The complex motion of the beads driven by the applied field, the dipole-dipole interaction between the beads, and the hydrodynamic flow of the viscous medium result in a time evolution of the tree structure towards states of lower resistance or higher dissipation and thus higher rates of entropy production. The resulting end-directed evolution manifests as the tree moving to locations seeking higher current, the current that sustains its structure and dynamics. The study of end-directed evolution in the dissipative structure gives us a means to distinguish the fundamental difference between machines and organisms and opens a path for the formulation of physics of organisms.

  14. Perspectives on communication problems in the English-speaking Caribbean.

    PubMed

    Okwesa, B A

    1984-03-01

    The Caribbean is experiencing a host of serious socioeconomic problems that prevent the majority of the population from realizing and maintaining a satisfactory standard of living. Food and Nutrition Surveys of some countries identified a lack of information on health, food, and nutrition as a primary reason for the prevalence of malnutrition, infectious diseases, and nutrition related diseases. "Misinformation" creates an often insurmountable barrier to effective communication between source and receiver, in this case the health, food, and nutrition sector and the wider community. Misinformation occurs when the message is either incorrect, incomplete, inconsistent with other messages in the same program, or contradictory. This element of "misinformation" can negate the effectiveness of the message and an entire communication program. Some examples are cited which show that in programs aimed at effecting change in attitude or behavior it is essential to ensure that messages are clearly communicated to avoid misunderstanding and the right infrastructure is in place for the innovation proposed by the message to be carried out. In the Jamaica Nutrition Education Program (JNEP) were used to communicate the messages. Evaluation revealed that health staff were providing incorrect and contradictory advice about breastfeeding, which showed that they lacked basic information on the subject. In Barbados, despite an intensified health education campaign, face to face instruction in the clinics, and extensive use of the Caribbean Food and Nutrition Institute (CFNI) Breastfeeding Package as well as other locally developed materials, a marked decline in breastfeeding was recorded over the 1969-81 survey period. Misinformation and misunderstanding among mothers were identified as the key reasons for the failure of breastfeeding. In relation to the decline in breaastfeeding and incorrect weaning practices, mass media was implicated as luring mothers away from natural feeding

  15. Problem-Based Learning Research in Anesthesia Teaching: Current Status and Future Perspective

    PubMed Central

    Chilkoti, G.; Mohta, M.; Wadhwa, R.; Saxena, A. K.

    2014-01-01

    The teaching curriculum in anesthesia involves traditional teaching methods like topic-based didactic lectures, seminars, and journal clubs; intraoperative apprenticeship; and problem-based learning (PBL) and simulation. The advantages of incorporating PBL in anesthesia teaching include development of skills like clinical reasoning, critical thinking, and self-directed learning; in addition it also helps in developing a broader perspective of case scenarios. The present paper discusses the characteristics, key elements, and goals of PBL; various PBL methods available; lacunae in the existing knowledge of PBL research; its current status and future perspectives in anesthesia teaching. PMID:24982673

  16. A Topological Perspective of Neural Network Structure

    NASA Astrophysics Data System (ADS)

    Sizemore, Ann; Giusti, Chad; Cieslak, Matthew; Grafton, Scott; Bassett, Danielle

    The wiring patterns of white matter tracts between brain regions inform functional capabilities of the neural network. Indeed, densely connected and cyclically arranged cognitive systems may communicate and thus perform distinctly. However, previously employed graph theoretical statistics are local in nature and thus insensitive to such global structure. Here we present an investigation of the structural neural network in eight healthy individuals using persistent homology. An extension of homology to weighted networks, persistent homology records both circuits and cliques (all-to-all connected subgraphs) through a repetitive thresholding process, thus perceiving structural motifs. We report structural features found across patients and discuss brain regions responsible for these patterns, finally considering the implications of such motifs in relation to cognitive function.

  17. Water quality objectives for mixtures of toxic chemicals: problems and perspectives.

    PubMed

    Vighi, M; Altenburger, R; Arrhenius, A; Backhaus, T; Bödeker, W; Blanck, H; Consolaro, F; Faust, M; Finizio, A; Froehner, K; Gramatica, P; Grimme, L H; Grönvall, F; Hamer, V; Scholze, M; Walter, H

    2003-02-01

    The need to develop water quality objectives not only for single substances but also for mixtures of chemicals seems evident. For that purpose, the conceptual basis could be the use of the two existing biometric models: concentration addition (CA) and independent action (IA), which is also called response addition. Both may allow calculation of the toxicity of mixtures of chemicals with similar modes of action (CA) or dissimilar modes of action (IA), respectively. The joint research project Prediction and Assessment of the Aquatic Toxicity of Mixtures of Chemicals (PREDICT) within the framework of the IVth Environment and Climate Programme of the European Commission, provided the opportunity to address (a) chemometric and QSAR criteria to classify substances as supposedly similarly or dissimilarly acting; (b) the predictive values of both models for the toxicity of mixtures at low, statistically nonsignificant effect concentrations of the individual components; and (c) the predictability of mixture toxicity at higher levels of biological complexity. In this article, the general outline, methodological approach, and some preliminary findings of PREDICT are presented. A procedure for classifying chemicals in relation to their structural and toxicological similarities has been developed. The predictive capabilities of CA and IA models have been demonstrated for single species and, to some extent, for multispecies testing. The role of very low effect concentrations in multiple mixtures has been evaluated. Problems and perspectives concerning the development of water quality objectives for mixtures are discussed.

  18. Structural dynamics technology research in NASA: Perspective on future needs

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The perspective of a NASA ad hoc study group on future research needs in structural dynamics within the aerospace industry is presented. The common aspects of the design process across the industry are identified and the role of structural dynamics is established through a discussion of various design considerations having their basis in structural dynamics. The specific structural dynamics issues involved are identified and assessed as to their current technological status and trends. Projections of future requirements based on this assessment are made and areas of research to meet them are identified.

  19. Carl Woese: a structural biologist's perspective.

    PubMed

    Moore, Peter B

    2014-01-01

    Not long after Carl Woese died, I received a message from Robin Gutell asking if I would contribute an article to this issue of RNA Biology. While my admiration for Carl's contributions to biology knows no bounds, I did not know him well personally. For that reason I advised Robin to strike my name off the list of contributors and replace it with that of someone who is better qualified than I am, but he persisted, and here we are. I guess Robin thought it would be useful to hear from one of those who admired Carl from afar. The naïve outsider might find it surprising that a structural biologist like me, who worries about the minutia of the three-dimensional structures of biological macromolecules, would ever have had anything in common with a big-picture, evolutionary biologist like Carl, but I did. What we shared was an interest in the structures of RNAs, especially rRNAs.

  20. Conceptualizing international labor migration: a structuration perspective.

    PubMed

    Goss, J D; Lindquist, B

    1995-01-01

    "This article applies the theory of structuration to international labor migration using case study material from the Philippines. It first provides a brief review of the functional and structural approaches to understanding labor migration and the theoretical impasse that has been created between them. It then reviews several attempts to resolve this impasse, including systems and networks approaches; these solutions are rejected on theoretical and empirical grounds. We suggest that migrant institutions may be a more appropriate mid-level concept than households or social networks to articulate various levels of analysis. We develop this concept in the context of the structuration theory of Anthony Giddens and attempt to apply this to the Philippines, concluding that this framework is eminently suited for further research on international labor migration."

  1. A VLSI structure for the deadlock avoidance problem

    SciTech Connect

    Bertolazzi, P.; Bongiovanni, G.

    1985-11-01

    In this paper the authors present two VLSI structures implementing the banker's algorithm for the deadlock avoidance problem, and we derive the area x (time)/sup 2/ lower bound for such an algorithm. The first structure is based on the VLSI mesh of trees. The second structure is a modification of the first one, and it approaches more closely the theoretical lower bound.

  2. Interface problems: Structural constraints on interpretation?

    PubMed Central

    Frazier, Lyn; Clifton, Charles; Rayner, Keith; Deevy, Patricia; Koh, Sungryong; Bader, Markus

    2006-01-01

    Five experiments investigated the interpretation of quantified noun phrases in relation to discourse structure. They demonstrated, using questionnaire and on-line reading techniques, that readers in English prefer to give a quantified noun phrase in (VP-external) subject position a presuppositional interpretation, in which the noun phrase limits or restricts the interpretation of an already available set, rather than giving it a nonpresuppositional or existential interpretation, in which it introduces completely new entities into the discourse. Experiment 1 showed that readers prefer a presuppositional interpretation of three ships over the existential interpretation in Five ships appeared on the horizon. Three ships sank. Experiment 2 showed longer reading times in sentences that are disambiguated toward the existential interpretation than in sentences that permit the presuppositional interpretation. Experiment 3 suggested that the presuppositional preference is greater when the phrase three ships occurs outside the verb phrase than when it occurs inside the verb phrase. Experiment 4 showed that Korean subjects marked with a topic marker received more presuppositional interpretations than subjects marked with a nominative marker. Experiment 5 showed that German subjects in VP-external (but nontopic) position received more presuppositional interpretations than VP-internal subjects. The results suggest the syntactic position of a phrase is one determinant of its interpretation, as expected according to the mapping hypothesis of Diesing (1990). PMID:16050443

  3. What makes a problem an ethical problem? An empirical perspective on the nature of ethical problems in general practice

    PubMed Central

    Braunack-Mayer, A. J.

    2001-01-01

    Whilst there has been considerable debate about the fit between moral theory and moral reasoning in everyday life, the way in which moral problems are defined has rarely been questioned. This paper presents a qualitative analysis of interviews conducted with 15 general practitioners (GPs) in South Australia to argue that the way in which the bioethics literature defines an ethical dilemma captures only some of the range of lay views about the nature of ethical problems. The bioethics literature has defined ethical dilemmas in terms of conflict and choice between values, beliefs and options for action. While some of the views of some of the GPs in this study about the nature of their ethical dilemmas certainly accorded with this definition, other explanations of the ethical nature of their problems revolved around the publicity associated with the issues they were discussing, concern about their relationships with patients, and anxiety about threats to their integrity and reputation. The variety of views about what makes a problem a moral problem indicates that the moral domain is perhaps wider and richer than mainstream bioethics would generally allow. Key Words: Empirical ethics • general practice • qualitative research PMID:11314166

  4. What makes a problem an ethical problem? An empirical perspective on the nature of ethical problems in general practice.

    PubMed

    Braunack-Mayer, A J

    2001-04-01

    Whilst there has been considerable debate about the fit between moral theory and moral reasoning in everyday life, the way in which moral problems are defined has rarely been questioned. This paper presents a qualitative analysis of interviews conducted with 15 general practitioners (GPs) in South Australia to argue that the way in which the bioethics literature defines an ethical dilemma captures only some of the range of lay views about the nature of ethical problems. The bioethics literature has defined ethical dilemmas in terms of conflict and choice between values, beliefs and options for action. While some of the views of some of the GPs in this study about the nature of their ethical dilemmas certainly accorded with this definition, other explanations of the ethical nature of their problems revolved around the publicity associated with the issues they were discussing, concern about their relationships with patients, and anxiety about threats to their integrity and reputation. The variety of views about what makes a problem a moral problem indicates that the moral domain is perhaps wider and richer than mainstream bioethics would generally allow.

  5. Effective chronic disease management: patients' perspectives on medication-related problems.

    PubMed

    Gordon, Karen; Smith, Felicity; Dhillon, Soraya

    2007-03-01

    To examine medication-related problems from the perspective of patients with a chronic condition and to identify how they may be supported in managing their medication. Patients prescribed medication for cardiovascular disease were recruited through five general medical surgeries and four community pharmacies in south London. Data were collected in 98 face-to-face interviews in participants' own homes. Interviews were designed to enable a detailed and holistic exploration of medication-related problems from participants' perspectives. Data were audio-recorded and transcribed verbatim to allow qualitative analysis. Five broad categories of medication-related problem emerged which were examined in the context of patients' perspectives on, and experiences of, the use of medicines and health services. These were concerns about and management of side effects; differing views regarding the use of medicines; cognitive, practical and sensory problems; lack of information or understanding; and problems with access to, and organisation of, services. All categories of problem had potential implications for the success of therapy in that they created barriers to adherence, access to medication or informed decision-making. The study demonstrated how patients actively engage in decision-making about their medicines in the home, if not in the consultation. The five categories of problem provide a focus for interventions by health professionals to support patients in achieving optimal theory outcomes. They demonstrate the need for a comprehensive approach, spanning patient education to the systems of delivery of care. Within the NHS in Britain, policy and practice initiatives are being designed to achieve this end. Further research should focus on the evaluation of professional practices and service developments in supporting patients in the self-management of their medicines.

  6. New perspectives on the Popigai impact structure

    NASA Technical Reports Server (NTRS)

    Garvin, J. B.; Deino, A. L.

    1992-01-01

    The record of large-scale cratering on Earth is scant, and the only currently 'proven' 100-km-class impact structure known to have formed within the Cenozoic is Popigai, located in the Siberian Arctic at 71.5 deg N, 111 deg E. Popigai is clearly a multiringed impact basin formed within the crystalline shield rocks (Anabar) and platform sediments of the Siberian taiga, and estimates of the volume of preserved impact melt typically exceed 1700 cu km, which is within a factor of 2-3 of what would be predicted using scaling relationships. We present the preliminary results of an analysis of the present-day topography of the Popigai structure, together with refined absolute age estimates, in order to reconstruct the pre-erosional morphology of the basin, as well as to quantify the erosion or sediment infill rates in the Popigai region.

  7. Human sulfatases: a structural perspective to catalysis.

    PubMed

    Ghosh, D

    2007-08-01

    The sulfatase family of enzymes catalyzes hydrolysis of sulfate ester bonds of a wide variety of substrates. Seventeen genes have been identified in this class of sulfatases, many of which are associated with genetic disorders leading to reduction or loss of function of the corresponding enzymes. Amino acid sequence homology suggests that the enzymes have similar overall folds, mechanisms of action, and bivalent metal ion-binding sites. A catalytic cysteine residue, strictly conserved in prokaryotic and eukaryotic sulfatases, is post-translationally modified into a formylglycine. Hydroxylation of the formylglycine residue by a water molecule forming the activated hydroxylformylglycine (a formylglycine hydrate or a gem-diol) is a necessary step for the enzyme's sulfatase activity. Crystal structures of three human sulfatases, arylsulfatases A and B(ARSA and ARSB), and estrone/dehydroepiandrosterone sulfatase or steroid sulfatase (STS), also known as arylsulfatase C, have been determined. While ARSA and ARSB are water-soluble enzymes, STS has a hydrophobic domain and is an integral membrane protein of the endoplasmic reticulum. In this article, we compare and contrast sulfatase structures and revisit the proposed catalytic mechanism in light of available structural and functional data. Examination of the STS active site reveals substrate-specific interactions previously identified as the estrogen-recognition motif. Because of the proximity of the catalytic cleft of STS to the membrane surface, the lipid bilayer has a critical role in the constitution of the active site, unlike other sulfatases.

  8. Model Structure Determination and Identifiability Problems in System Identification.

    DTIC Science & Technology

    System identification has become one of the most active areas in system theory and its applications. In many engineering applications where the...estimation. As the authors extend the concept of system identification to those classes of problems where prior knowledge on structure is limited, some...basic problems other than parameter estimation become important. System identification consists of three basic sub-problems: (1) pre-estimation

  9. Structural qualia: a solution to the hard problem of consciousness

    PubMed Central

    Loorits, Kristjan

    2014-01-01

    The hard problem of consciousness has been often claimed to be unsolvable by the methods of traditional empirical sciences. It has been argued that all the objects of empirical sciences can be fully analyzed in structural terms but that consciousness is (or has) something over and above its structure. However, modern neuroscience has introduced a theoretical framework in which also the apparently non-structural aspects of consciousness, namely the so called qualia or qualitative properties, can be analyzed in structural terms. That framework allows us to see qualia as something compositional with internal structures that fully determine their qualitative nature. Moreover, those internal structures can be identified which certain neural patterns. Thus consciousness as a whole can be seen as a complex neural pattern that misperceives some of its own highly complex structural properties as monadic and qualitative. Such neural pattern is analyzable in fully structural terms and thereby the hard problem is solved. PMID:24672510

  10. Analytic semigroups: Applications to inverse problems for flexible structures

    NASA Technical Reports Server (NTRS)

    Banks, H. T.; Rebnord, D. A.

    1990-01-01

    Convergence and stability results for least squares inverse problems involving systems described by analytic semigroups are presented. The practical importance of these results is demonstrated by application to several examples from problems of estimation of material parameters in flexible structures using accelerometer data.

  11. A structural perspective of CTD function.

    PubMed

    Meinhart, Anton; Kamenski, Tomislav; Hoeppner, Sabine; Baumli, Sonja; Cramer, Patrick

    2005-06-15

    The C-terminal domain (CTD) of RNA polymerase II (Pol II) integrates nuclear events by binding proteins involved in mRNA biogenesis. CTD-binding proteins recognize a specific CTD phosphorylation pattern, which changes during the transcription cycle, due to the action of CTD-modifying enzymes. Structural and functional studies of CTD-binding and -modifying proteins now reveal some of the mechanisms underlying CTD function. Proteins recognize CTD phosphorylation patterns either directly, by contacting phosphorylated residues, or indirectly, without contact to the phosphate. The catalytic mechanisms of CTD kinases and phosphatases are known, but the basis for CTD specificity of these enzymes remains to be understood.

  12. The Chinese healthcare system: structure, problems and challenges.

    PubMed

    Hougaard, Jens Leth; Osterdal, Lars Peter; Yu, Yi

    2011-01-01

    We describe the structure and present situation of the Chinese healthcare system and discuss its primary problems and challenges. We discuss problems with inefficient burden sharing, adverse provider incentives and huge inequities, and seek explanations in the structural features of the Chinese healthcare system. The current situation will be further challenged in the future by an aging population, an increasing need for privatization and growing expectations about quality of healthcare.

  13. [Individuals and their peers: a structural perspective].

    PubMed

    Schäfer, Mechthild; von Salisch, Maria

    2013-01-01

    Peer relationships are diverse in the sense that their degree of obligation, their intensity, their stability and even their number of participants vary. At the same time they have effects on the intraindividual and interindividual development of children and adolescents who tend to value them highly. Sociometric peer nominations provide one way of describing the complexity of peer relationships and of analyzing their various determinants. Peers are sources of information in the context of a defined system like a classroom in school. The consistency of this information (how many children like A and how many children like B), its reciprocity, and its stability are structural parameters that--in concert with other psychological constructs--may provide valuable cues and predictions about the optimal conditions for a positive peer socialization. The present article attempts to use these structural elements as the point of departure by navigating through the complexity, in order to delineate existing knowledge before the background of open questions and important question marks.

  14. Recent advances in numerical analysis of structural eigenvalue problems

    NASA Technical Reports Server (NTRS)

    Gupta, K. K.

    1973-01-01

    A wide range of eigenvalue problems encountered in practical structural engineering analyses is defined, in which the structures are assumed to be discretized by any suitable technique such as the finite-element method. A review of the usual numerical procedures for the solution of such eigenvalue problems is presented and is followed by an extensive account of recently developed eigenproblem solution procedures. Particular emphasis is placed on the new numerical algorithms and associated computer programs based on the Sturm sequence method. Eigenvalue algorithms developed for efficient solution of natural frequency and buckling problems of structures are presented, as well as some eigenvalue procedures formulated in connection with the solution of quadratic matrix equations associated with free vibration analysis of structures. A new algorithm is described for natural frequency analysis of damped structural systems.

  15. Recent advances in numerical analysis of structural eigenvalue problems

    NASA Technical Reports Server (NTRS)

    Gupta, K. K.

    1973-01-01

    A wide range of eigenvalue problems encountered in practical structural engineering analyses is defined, in which the structures are assumed to be discretized by any suitable technique such as the finite-element method. A review of the usual numerical procedures for the solution of such eigenvalue problems is presented and is followed by an extensive account of recently developed eigenproblem solution procedures. Particular emphasis is placed on the new numerical algorithms and associated computer programs based on the Sturm sequence method. Eigenvalue algorithms developed for efficient solution of natural frequency and buckling problems of structures are presented, as well as some eigenvalue procedures formulated in connection with the solution of quadratic matrix equations associated with free vibration analysis of structures. A new algorithm is described for natural frequency analysis of damped structural systems.

  16. Solving a generalized distance geometry problem for protein structure determination.

    PubMed

    Sit, Atilla; Wu, Zhijun

    2011-12-01

    We propose a new approach to the problem of determining an ensemble of protein structures with a set of interatomic distance bounds in NMR protein modeling. Similarly to X-ray crystallography, we assume that the protein has an equilibrium structure and the atoms fluctuate around their equilibrium positions. Then, the problem can be formulated as a generalized distance geometry problem, to find the equilibrium positions and maximal possible fluctuation radii for the atoms in the protein, subject to the condition that the fluctuations should be within the given distance bounds. We describe the scientific background of the work, the motivation of the new approach and the formulation of the problem. We develop a geometric buildup algorithm for an approximate solution to the problem and present some preliminary test results as a first step concept proofing. We also discuss related theoretical and computational issues and potential impacts of this work in NMR protein modeling.

  17. The Lunar Internal Structure Model: Problems and Solutions

    NASA Astrophysics Data System (ADS)

    Nefedyev, Yuri; Gusev, Alexander; Petrova, Natalia; Varaksina, Natalia

    The report is devoted the problems of the internal structure and gravitational field of the Moon. New data received from 14 newest instruments installed on low-orbit satellite Kaguya essentially enriched our knowledge of the Moon. Chinese satellite ChagE-1 and Indian Сhandrayan-1 have demonstrated strong potential of China and India in the field of lunar research and obtained new data on gravitational field, mascons, crust, and geochemical composition of the circumlunar space. Internal structure of the Moon: There are some essential arguments in favor of existence of a small-sized Moon’s core made of metallic iron alloyed with a small amount of sulfur and/or oxygen, and availability of hot viscous lower mantle. Structure of gravitational field of the Moon, determined by the comparison of high-precision trajectory measurements by Lunar Prospector (1998- 1999) with the results of laser altimetry obtained by Clementine (1994), as well as with data sets of laser ranging of the Moon (1970-2006), assumes the presence of a metal core. Interpretation of the polar moment value within the framework of chemical, thermal and density models of lunar crust and mantle informed conclusions about the weight and size of the core. LLR analysis of dissipation of rotation of the Moon points at two possible sources of dissipation: monthly solid-state inflows and liquid core, rotation of which differs from viscous-elastic mantle. Liquid (melted) core has its unique impact on the Moon’s rotation. In particular, there are two force moments due to topographical and phase interaction at the boundary between liquid core and elastic mantle (CMB). Liquid core can rotate independently from solid mantle Selenoid satellites (SS) open new and most perspective opportunities in the study of gravitational field and the Moon’s figure. SSs “Moon 10”, “Apollo”, “Clementine”, “Lunar Prospector” trajectory tracking data processing has allowed for identification of coefficients in

  18. Variational structure of inverse problems in wave propagation and vibration

    SciTech Connect

    Berryman, J.G.

    1995-03-01

    Practical algorithms for solving realistic inverse problems may often be viewed as problems in nonlinear programming with the data serving as constraints. Such problems are most easily analyzed when it is possible to segment the solution space into regions that are feasible (satisfying all the known constraints) and infeasible (violating some of the constraints). Then, if the feasible set is convex or at least compact, the solution to the problem will normally lie on the boundary of the feasible set. A nonlinear program may seek the solution by systematically exploring the boundary while satisfying progressively more constraints. Examples of inverse problems in wave propagation (traveltime tomography) and vibration (modal analysis) will be presented to illustrate how the variational structure of these problems may be used to create nonlinear programs using implicit variational constraints.

  19. Exploring Teacher and School Resilience as a New Perspective to Solve Persistent Problems in the Educational Sector

    ERIC Educational Resources Information Center

    Schelvis, Roosmarijn M. C.; Zwetsloot, Gerard I. J. M.; Bos, Evelien H.; Wiezer, Noortje M.

    2014-01-01

    In this paper, we will explore the relevance, meaning and perspectives of teacher, team and school resilience. The central research questions are: does the concept of teacher, team and school resilience offer new and promising perspectives on persistent problems in the educational sector? And secondly; how can resilience at individual, team and…

  20. Exploring Teacher and School Resilience as a New Perspective to Solve Persistent Problems in the Educational Sector

    ERIC Educational Resources Information Center

    Schelvis, Roosmarijn M. C.; Zwetsloot, Gerard I. J. M.; Bos, Evelien H.; Wiezer, Noortje M.

    2014-01-01

    In this paper, we will explore the relevance, meaning and perspectives of teacher, team and school resilience. The central research questions are: does the concept of teacher, team and school resilience offer new and promising perspectives on persistent problems in the educational sector? And secondly; how can resilience at individual, team and…

  1. Whither Ribosome Structure and Dynamics Research? (A Perspective).

    PubMed

    Frank, Joachim

    2016-09-11

    As high-resolution cryogenic electron microscopy (cryo-EM) structures of ribosomes proliferate, at resolutions that allow atomic interactions to be visualized, this article attempts to give a perspective on the way research on ribosome structure and dynamics may be headed, and particularly the new opportunities we have gained through recent advances in cryo-EM. It is pointed out that single-molecule FRET and cryo-EM form natural complements in the characterization of ribosome dynamics and transitions among equilibrating states of in vitro translational systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Comparing Structural Perspectives on Medical Informatics: EMBASE vs. MEDLINE

    PubMed Central

    Morris, Theodore Allan

    2003-01-01

    Previous bibliometric analyses of Medical Informatics’ internal structure used MEDLINE records as the unit of study. EMBASE, a product of Excerpta Medica, carries a wider international scope and offers complementary retrieval results to MEDLINE. Since much medical informatics critical thinking originated abroad and migrated to North America, this difference in coverage may also indicate a different perspective of “what constitutes medical informatics.” Using traditional bibliometric and multivariate data analysis techniques, the present work examines EMBASE indexing records for the same 1995–1999 time frame as earlier MEDLINE studies to identify and compare structural features of the field.. PMID:14728448

  3. Is epidemiology correcting its vision problem? A perspective on our perspective: 2012 presidential address for American College of Epidemiology.

    PubMed

    McKeown, Robert E

    2013-10-01

    Epidemiology, like all disciplines, exists within and is shaped by a culture that frames its ways of understanding. In the last 60 years epidemiology as a discipline and scientific approach has undergone major transition, but remains challenged by vestiges of the limiting frameworks of our origins which shape the way we approach questions, and even the questions we choose to investigate. A part of the current transformation is a reframing of our perspective and a broadening of our methods to encourage creativity and to encompass new types of evidence and new approaches to investigation and interpretation. Epidemiologists are developing innovative ways to approach increasingly complex problems and becoming more open to multi-disciplinary approaches to solving epidemiologic challenges.

  4. Supporting teachers who introduce curricular innovations into their classrooms: A problem-solving perspective

    NASA Astrophysics Data System (ADS)

    Yerushalmi, Edit; Eylon, Bat-Sheva

    2013-06-01

    When classroom teachers introduce curricular innovations that conflict with their former deeply rooted practices, the teachers themselves experience a process of change. One professional development framework intended to support this change is the customization workshop, in which teachers cooperatively customize innovations to their own classroom contexts, reflect on the strengths and weaknesses of classroom implementation, and refine their innovations. Two goals sometimes conflict in such workshops: developing teachers’ skills as reflective practitioners (process) and maintaining crucial characteristics of the original innovations (product). This paper explores how to meet both challenges using the insights from a perspective that provides a striking parallel: developing expertlike problem-solving skills (process) as well as conceptual understanding (product) in the physics classroom. We apply this perspective by (a) characterizing an expertlike approach to pedagogical problem solving in the context of customization workshops, (b) determining the nature of pedagogical problems best suited for developing such an expertlike approach, (c) suggesting how to design customization workshops that support teachers to develop an expertlike approach to pedagogical problem solving. In particular, we hypothesize that applying cognitive apprenticeship in customization workshops in a manner similar to its application in the teaching of expertlike problem solving in the physics classroom should effectively help teachers approach the pedagogical problem of customization in an expertlike manner. We support our hypothesis with an empirical study of three year-long cooperative customization workshops for physics teachers that differed in terms of mentoring approach. We examined the questions (a) under which mentoring approaches did teachers perform an expertlike pedagogical problem-solving process and (b) which practices and perceptions emerged through execution of this process?

  5. Assessment of parenting and developmental problems in toddlers: development and feasibility of a structured interview.

    PubMed

    Staal, I I E; van den Brink, H A G; Hermanns, J M A; Schrijvers, A J P; van Stel, H F

    2011-07-01

    Assessment of (early signs of) parenting and developmental problems in young children by preventive child health care (CHC) workers is recommended, but no validated instruments exist. The aim of this project was to develop and test an instrument for early detection and assessment of problems in toddlers, using the perspectives and experience of both the parent and the professional. Using an iterative process, we adapted and expanded a structured interview on need for parenting support into the Structured Problem Analysis of Raising Kids (SPARK). The SPARK consists of 16 subject areas, ranging from somatic health to family issues. The SPARK was tested in daily practice for feasibility and discriminative capacity. The sample consisted of all toddlers aged 18 months living in Zeeland, a province of the Netherlands, during the study period (n= 1140). The response rate was 97.8%. Although the median level of support needed according to the SPARK was low, 4.5% of the toddlers and their parents required intensive help or immediate action. The risk assessment showed 2.9% high, 16.5% increased and 80.6% low risk for parenting and developmental problems. The risk assessment of the CHC professional was associated with known risk factors for child maltreatment. This study shows that a structured interview, named the SPARK, is feasible in daily practice and clarifies risks and care needs for parenting and developmental problems in toddlers. © 2011 Blackwell Publishing Ltd.

  6. Cardiac Tissue Structure, Properties, and Performance: A Materials Science Perspective

    PubMed Central

    Golob, Mark; Moss, Richard L.; Chesler, Naomi C.

    2014-01-01

    From an engineering perspective, many forms of heart disease can be thought of as a reduction in biomaterial performance, in which the biomaterial is the tissue comprising the ventricular wall. In materials science, the structure and properties of a material are recognized to be interconnected with performance. In addition, for most measurements of structure, properties, and performance, some processing is required. Here, we review the current state of knowledge regarding cardiac tissue structure, properties, and performance as well as the processing steps taken to acquire those measurements. Understanding the impact of these factors and their interactions may enhance our understanding of heart function and heart failure. We also review design considerations for cardiac tissue property and performance measurements because, to date, most data on cardiac tissue has been obtained under non-physiological loading conditions. Novel measurement systems that account for these design considerations may improve future experiments and lead to greater insight into cardiac tissue structure, properties, and ultimately performance. PMID:25081385

  7. The damper placement problem for large flexible space structures

    NASA Technical Reports Server (NTRS)

    Kincaid, Rex K.

    1992-01-01

    The damper placement problem for large flexible space truss structures is formulated as a combinatorial optimization problem. The objective is to determine the p truss members of the structure to replace with active (or passive) dampers so that the modal damping ratio is as large as possible for all significant modes of vibration. Equivalently, given a strain energy matrix with rows indexed on the modes and the columns indexed on the truss members, we seek to find the set of p columns such that the smallest row sum, over the p columns, is maximized. We develop a tabu search heuristic for the damper placement problems on the Controls Structures Interaction (CSI) Phase 1 Evolutionary Model (10 modes and 1507 truss members). The resulting solutions are shown to be of high quality.

  8. Home care assistants’ perspectives on detecting mental health problems and promoting mental health among community-dwelling seniors with multimorbidity

    PubMed Central

    Grundberg, Åke; Hansson, Anna; Religa, Dorota; Hillerås, Pernilla

    2016-01-01

    Introduction Elderly people with multiple chronic conditions, or multimorbidity, are at risk of developing poor mental health. These seniors often remain in their homes with support from home care assistants (HCAs). Mental health promotion by HCAs needs to be studied further because they may be among the first to observe changes in clients’ mental health status. Aim To describe HCAs’ perspectives on detecting mental health problems and promoting mental health among homebound seniors with multimorbidity. Methods We applied a descriptive qualitative study design using semi-structured interviews. Content analyses were performed on five focus group interviews conducted in 2014 with 26 HCAs. Results Most HCAs stated that they were experienced in caring for clients with mental health problems such as anxiety, depression, sleep problems, and high alcohol consumption. The HCAs mentioned as causes, or risk factors, multiple chronic conditions, feelings of loneliness, and social isolation. The findings reveal that continuity of care and seniors’ own thoughts and perceptions were essential to detecting mental health problems. Observation, collaboration, and social support emerged as important means of detecting mental health problems and promoting mental health. Conclusion The HCAs had knowledge of risk factors, but they seemed insecure about which health professionals had the primary responsibility for mental health. They also seemed to have detected early signs of mental health problems, even though good personal knowledge of the client and continuity in home visits were crucial to do so. When it came to mental health promotion, the suggestions related to the aim of ending social isolation, decreasing feelings of loneliness, and increasing physical activity. The results indicate that the HCAs seemed dependent on supervision by district nurses and on care managers’ decisions to support the needed care, to schedule assignments related to the detection of mental health

  9. Environmental Policies and Problems in Japan, China, and Hong Kong: Travel Perspectives.

    ERIC Educational Resources Information Center

    Therivel, Riki; Wrisberg, Mette

    1988-01-01

    Compared are some of the environmental planning policies and developmental policies of three regions of the Far East. Discusses the relationship between social structures and environmental problems such as pollution, erosion, waste disposal, and the uses of technology. (CW)

  10. Environmental Policies and Problems in Japan, China, and Hong Kong: Travel Perspectives.

    ERIC Educational Resources Information Center

    Therivel, Riki; Wrisberg, Mette

    1988-01-01

    Compared are some of the environmental planning policies and developmental policies of three regions of the Far East. Discusses the relationship between social structures and environmental problems such as pollution, erosion, waste disposal, and the uses of technology. (CW)

  11. Different perspectives on emotional and behavioural problems in unaccompanied refugee children and adolescents.

    PubMed

    Derluyn, Ilse; Broekaert, Eric

    2007-04-01

    This study aims, firstly, to investigate the prevalence of emotional and behavioural problems in unaccompanied refugee children and adolescents living in Belgium. Secondly, this study compares the perspectives of the adolescents with those of social workers on the adolescents' emotional well-being. A total of 166 unaccompanied refugee children and adolescents, living in different large- and small-scale centres, in foster care or alone, participated in the study. Of them, 142 completed self-report questionnaires on emotional and behavioural problems (HSCL-37A, SDQ-self and RATS) and traumatic experiences (SLE), and for 124 refugee youths, social workers filled in two questionnaires on emotional and behavioural problems (CBCL/6-18 and SDQ-parent). Between 37 and 47% of the unaccompanied refugee youths have severe or very severe symptoms of anxiety, depression and post-traumatic stress. Girls and those having experienced many traumatic events are at even higher risk for the development of these emotional problems. Social workers also report a high prevalence of internalising problems in this population and they also report important externalising problems in unaccompanied refugee youths. Being unaccompanied is an important risk factor for the emotional well-being of refugee children and adolescents. Therefore, appropriate measures on reception and care should be taken in order to support these youths.

  12. Hydrates of natural gases and small molecules: structures, properties, and exploitation perspectives.

    PubMed

    Barone, Guido; Chianese, Elena

    2009-01-01

    Starting from the discovery, in the mid-1930s, that petroleum pipelines in the colder regions of the Northern hemisphere contained crusts of some crystals, and were often blocked by them, a short history of the development of research on the structures, properties, and possible exploitation of the class of inclusion compounds known as gas hydrates is given. The state of the assessment of the natural reservoirs and their perspectives for exploitation are presented, together with an analysis of the hypotheses on the origins of the hydrates. Finally, the phase diagrams are shown in relation to environmental problems arising from the instability of the hydrate fields due to global warming or geological activity.

  13. The Association between Sleep Problems and Psychotic Symptoms in the General Population: A Global Perspective

    PubMed Central

    Koyanagi, Ai; Stickley, Andrew

    2015-01-01

    Study Objectives: To assess the prevalence of sleep problems and their association with psychotic symptoms using a global database. Design: Community-based cross-sectional study. Setting: Data were analyzed from the World Health Organization's World Health Survey (WHS), a population-based survey conducted in 70 countries between 2002 and 2004. Patients or Participants: 261,547 individuals aged ≥ 18 years from 56 countries. Interventions: N/A. Measurements and Results: The presence of psychotic symptoms in the past 12 months was established using 4 questions pertaining to positive symptoms from the psychosis screening module of the Composite International Diagnostic Interview. Sleep problems referred to severe or extreme sleep problems in the past 30 days. Multivariable logistic regression was used to estimate the associations. The overall prevalence of sleep problems was 7.6% and ranged from 1.6% (China) to 18.6% (Morocco). Sleep problems were associated with significantly higher odds for at least one psychotic symptom in the vast majority of countries. In the pooled sample, after adjusting for demographic factors, alcohol consumption, smoking, and chronic medical conditions, having sleep problems resulted in an odds ratio (OR) for at least one psychotic symptom of 2.41 (95% confidence interval [CI] 2.18–2.65). This OR was 1.59 (1.40–1.81) when further adjusted for anxiety and depression. Conclusions: A strong association between sleep problems and psychotic symptoms was observed globally. These results have clinical implications and serve as a basis for future studies to elucidate the causal association between psychotic symptoms and sleep problems. Citation: Koyanagi A, Stickley A. The association between sleep problems and psychotic symptoms in the general population: a global perspective. SLEEP 2015;38(12):1875–1885. PMID:26085291

  14. A Qualitative Approach to a Better Understanding of the Problems Underlying Drug Shortages, as Viewed from Belgian, French and the European Union’s Perspectives

    PubMed Central

    Prokop, Anna; Pilc, Andrzej

    2015-01-01

    The problem of drug shortages has been reported worldwide, gaining prominence in multiple domains and several countries in recent years. The aim of the study was to analyze, characterise and assess this problem in Belgium and France, while also adopting a wider perspective from the European Union. A qualitative methodological approach was employed, including semi-structured interviews with the representatives of respective national health authorities, pharmaceutical companies and wholesalers, as well as hospital and community pharmacists. The research was conducted in early 2014. Four themes, which were identified through the interviews, were addressed in the paper, i.e. a) defining drug shortages, b) their dynamics and perception, c) their determinants, d) the role of the European and national institutions in coping with the problem. Three groups of determinants of drug shortages were identified throughout this study: manufacturing problems, distribution and supply problems, and problems related to economic aspects. Currently, the Member States of the European Union are striving to resolve the problem very much on their own, although a far more focused and dedicated collaboration may well prove instrumental in coping with drug shortages throughout Europe more effectively. To the best of the authors’ knowledge, this is the first qualitative study to investigate the characteristics, key determinants, and the problem drivers of drug shortages, focusing on this particular group of countries, while also adopting the European Union’s perspective. PMID:25942432

  15. A Qualitative Approach to a Better Understanding of the Problems Underlying Drug Shortages, as Viewed from Belgian, French and the European Union's Perspectives.

    PubMed

    Bogaert, Petronille; Bochenek, Tomasz; Prokop, Anna; Pilc, Andrzej

    2015-01-01

    The problem of drug shortages has been reported worldwide, gaining prominence in multiple domains and several countries in recent years. The aim of the study was to analyze, characterise and assess this problem in Belgium and France, while also adopting a wider perspective from the European Union. A qualitative methodological approach was employed, including semi-structured interviews with the representatives of respective national health authorities, pharmaceutical companies and wholesalers, as well as hospital and community pharmacists. The research was conducted in early 2014. Four themes, which were identified through the interviews, were addressed in the paper, i.e. a) defining drug shortages, b) their dynamics and perception, c) their determinants, d) the role of the European and national institutions in coping with the problem. Three groups of determinants of drug shortages were identified throughout this study: manufacturing problems, distribution and supply problems, and problems related to economic aspects. Currently, the Member States of the European Union are striving to resolve the problem very much on their own, although a far more focused and dedicated collaboration may well prove instrumental in coping with drug shortages throughout Europe more effectively. To the best of the authors' knowledge, this is the first qualitative study to investigate the characteristics, key determinants, and the problem drivers of drug shortages, focusing on this particular group of countries, while also adopting the European Union's perspective.

  16. [Research on problem of exogenous pollution of Chinese medicine resources from perspective of circular economy].

    PubMed

    Yang, Yi; Tian, Kan; Tian, Hong

    2016-08-01

    Based on the in-depth analysis of the current situation of the exogenous pollution of Chinese medicine resources, this research mainly discusses the intrinsic link and practical significance between the development of circular economy in Chinese medicine resources and the control of the problem of the exogenous pollution from the perspective of circular economy, and proposes some suggestions to develop the recycling economy of Chinese medicine resources from the establishment of legal system, mechanism of development, production norms, industry standards and regulatory system of the recycling of Chinese medicine resources. Copyright© by the Chinese Pharmaceutical Association.

  17. [Methodology and problems in home monitoring of children with sleep-related respiratory disorders--perspectives].

    PubMed

    Wiater, A; Götz, W; Niewerth, H J

    1996-01-01

    In a pilot study we interviewed parents of 100 formerly home monitored infants about problems during the monitoring period. The duration of home monitoring was between 1 and 48 months (median 15 months). 95% of the parents reported false alarms. 66% of the infants had real alarms, in 50% of the infants interventions were necessary. 3% of the infants had to be resuscitated. Only 47% of the parents felt safe in the practice of resuscitation even though all parents had been trained before. Perspectives of improvement of home monitoring are discussed.

  18. Quantum engineering of superconducting structures: Principles, promise and problems

    NASA Astrophysics Data System (ADS)

    Zagoskin, Alexandre

    2017-07-01

    Quantum technologies went through an explosive development since the beginning of the century. The progress in the field of superconducting quantum structures was especially fast. As the result, the design and characterization of large quantum coherent structures became an engineering problem. We will discuss the current status of the emerging discipline of quantum engineering and possible ways of meeting its main challenge, the fundamental impossibility of an efficient modelling of a quantum system using classical means.

  19. Implementing the Japanese Problem-Solving Lesson Structure

    ERIC Educational Resources Information Center

    Groves, Susie

    2013-01-01

    While there has been worldwide interest in Japanese Lesson Study as a model for teacher professional learning, there has been less research into authentic implementation of the problem-solving lesson structure that underpins mathematics research lessons in Japan. Findings from a Lesson Study project involving teachers from three Victorian primary…

  20. Detection of structural deterioration and associated airline maintenance problems

    NASA Technical Reports Server (NTRS)

    Henniker, H. D.; Mitchell, R. G.

    1972-01-01

    Airline operations involving the detection of structural deterioration and associated maintenance problems are discussed. The standard approach to the maintenance and inspection of aircraft components and systems is described. The frequency of inspections and the application of preventive maintenance practices are examined. The types of failure which airline transport aircraft encounter and the steps taken to prevent catastrophic failure are reported.

  1. PARTI primitives for unstructured and block structured problems

    NASA Technical Reports Server (NTRS)

    Sussman, Alan; Saltz, Joel; Das, Raja; Gupta, S.; Mavriplis, Dimitri; Ponnusamy, Ravi; Crowley, Kay

    1992-01-01

    Described here is a set of primitives (PARTI) developed to efficiently execute unstructured and block structured problems on distributed memory parallel machines. We present experimental data from a 3-D unstructured Euler solver run on the Intel Touchstone Delta to demonstrate the usefulness of our methods.

  2. Family Structure, Community Context, and Adolescent Problem Behaviors

    ERIC Educational Resources Information Center

    Hoffman, John P.

    2006-01-01

    A number of models have been proposed to explain the relationship between family structure and adolescent problem behaviors, including several that consider parent-child relations, family income, stress, and residential mobility. However, studies have not explored whether the different types of communities within which families reside affect the…

  3. Time-Limited, Structured Youth Mentoring and Adolescent Problem Behaviors

    ERIC Educational Resources Information Center

    Weiler, Lindsey M.; Haddock, Shelley A.; Zimmerman, Toni S.; Henry, Kimberly L.; Krafchick, Jennifer L.; Youngblade, Lise M.

    2015-01-01

    Youth mentoring can have a profound impact on the lives of high-risk youth. This study presents the Campus Corps program, a time-limited (12-week), structured mentoring program for high-risk youth (ages 11--18), and results from a quasi-experimental pilot evaluation. Baseline and post-intervention problem behavior data from 315 offending youth…

  4. Structure linguistique: problemes de la constance et des variations (Linguistic Structure: Constance and Variation Problems).

    ERIC Educational Resources Information Center

    Mahmoudian, Morteza

    1980-01-01

    Language is viewed as a nonhomogeneous hierarchical system, where complex correlations between a psychological/social dimension (external) and a linguistic dimension (internal) permit measurements of the stability and acceptability of its structures. Frequency of occurrence and integration in the system are presented as the key factors in the…

  5. Automated problem list generation and physicians perspective from a pilot study.

    PubMed

    Devarakonda, Murthy V; Mehta, Neil; Tsou, Ching-Huei; Liang, Jennifer J; Nowacki, Amy S; Jelovsek, John Eric

    2017-09-01

    An accurate, comprehensive and up-to-date problem list can help clinicians provide patient-centered care. Unfortunately, problem lists created and maintained in electronic health records by providers tend to be inaccurate, duplicative and out of date. With advances in machine learning and natural language processing, it is possible to automatically generate a problem list from the data in the EHR and keep it current. In this paper, we describe an automated problem list generation method and report on insights from a pilot study of physicians' assessment of the generated problem lists compared to existing providers-curated problem lists in an institution's EHR system. The natural language processing and machine learning-based Watson(1) method models clinical thinking in identifying a patient's problem list using clinical notes and structured data. This pilot study assessed the Watson method and included 15 randomly selected, de-identified patient records from a large healthcare system that were each planned to be reviewed by at least two internal medicine physicians. The physicians created their own problem lists, and then evaluated the overall usefulness of their own problem lists (P), Watson generated problem lists (W), and the existing EHR problem lists (E) on a 10-point scale. The primary outcome was pairwise comparisons of P, W, and E. Six out of the 10 invited physicians completed 27 assessments of P, W, and E, and in process evaluated 732 Watson generated problems and 444 problems in the EHR system. As expected, physicians rated their own lists, P, highest. However, W was rated higher than E. Among 89% of assessments, Watson identified at least one important problem that physicians missed. Cognitive computing systems like this Watson system hold the potential for accurate, problem-list-centered summarization of patient records, potentially leading to increased efficiency, better clinical decision support, and improved quality of patient care. Copyright

  6. Dynamic Programming for Structured Continuous Markov Decision Problems

    NASA Technical Reports Server (NTRS)

    Dearden, Richard; Meuleau, Nicholas; Washington, Richard; Feng, Zhengzhu

    2004-01-01

    We describe an approach for exploiting structure in Markov Decision Processes with continuous state variables. At each step of the dynamic programming, the state space is dynamically partitioned into regions where the value function is the same throughout the region. We first describe the algorithm for piecewise constant representations. We then extend it to piecewise linear representations, using techniques from POMDPs to represent and reason about linear surfaces efficiently. We show that for complex, structured problems, our approach exploits the natural structure so that optimal solutions can be computed efficiently.

  7. Quantum inferring acausal structures and the Monty Hall problem

    NASA Astrophysics Data System (ADS)

    Kurzyk, Dariusz; Glos, Adam

    2016-12-01

    This paper presents a quantum version of the Monty Hall problem based upon the quantum inferring acausal structures, which can be identified with generalization of Bayesian networks. Considered structures are expressed in formalism of quantum information theory, where density operators are identified with quantum generalization of probability distributions. Conditional relations between quantum counterpart of random variables are described by quantum conditional operators. Presented quantum inferring structures are used to construct a model inspired by scenario of well-known Monty Hall game, where we show the differences between classical and quantum Bayesian reasoning.

  8. Can the Stark-Einstein law resolve the measurement problem from an animate perspective?

    PubMed

    Thaheld, Fred H

    2015-09-01

    Analysis of the Stark-Einstein law as it applies to the retinal molecule, which is part of the rhodopsin molecule within the rod cells of the retina, reveals that it may provide the solution to the measurement problem from an animate perspective. That it represents a natural boundary where the Schrödinger equation or wave function automatically goes from linear to nonlinear while remaining in a deterministic state. It will be possible in the near future to subject this theory to empirical tests as has been previously proposed. This analysis provides a contrast to the many decades well studied and debated inanimate measurement problem and would represent an addition to the Stark-Einstein law involving information carried by the photon. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. Finite element solution of transient fluid-structure interaction problems

    NASA Technical Reports Server (NTRS)

    Everstine, Gordon C.; Cheng, Raymond S.; Hambric, Stephen A.

    1991-01-01

    A finite element approach using NASTRAN is developed for solving time-dependent fluid-structure interaction problems, with emphasis on the transient scattering of acoustic waves from submerged elastic structures. Finite elements are used for modeling both structure and fluid domains to facilitate the graphical display of the wave motion through both media. For the liquid, the use of velocity potential as the fundamental unknown results in a symmetric matrix equation. The approach is illustrated for the problem of transient scattering from a submerged elastic spherical shell subjected to an incident tone burst. The use of an analogy between the equations of elasticity and the wave equation of acoustics, a necessary ingredient to the procedure, is summarized.

  10. A framework for solving ill-structured community problems

    NASA Astrophysics Data System (ADS)

    Keller, William Cotesworth

    A multifaceted protocol for solving ill-structured community problems has been developed. It embodies the lessons learned from the past by refining and extending features of previous models from the systems thinkers, and the fields of behavioral decision making and creative problem solving. The protocol also embraces additional features needed to address the unique aspects of community decision situations. The essential elements of the protocol are participants from the community, a problem-solving process, a systems picture, a facilitator, a modified Delphi method of communications, and technical expertise. This interdisciplinary framework has been tested by a quasi experiment with a real world community problem (the high cost of electrical power on Long Island, NY). Results indicate the protocol can enable members of the community to understand a complicated, ill-structured problem and guide them to action to solve the issue. However, the framework takes time (over one year in the test case) and will be inappropriate for crises where quick action is needed.

  11. MSClique: Multiple Structure Discovery through the Maximum Weighted Clique Problem

    PubMed Central

    Alquézar, René; Serratosa, Francesc; Moreno-Noguer, Francesc; Andrade-Cetto, Juan; González Ballester, Miguel Ángel

    2016-01-01

    We present a novel approach for feature correspondence and multiple structure discovery in computer vision. In contrast to existing methods, we exploit the fact that point-sets on the same structure usually lie close to each other, thus forming clusters in the image. Given a pair of input images, we initially extract points of interest and extract hierarchical representations by agglomerative clustering. We use the maximum weighted clique problem to find the set of corresponding clusters with maximum number of inliers representing the multiple structures at the correct scales. Our method is parameter-free and only needs two sets of points along with their tentative correspondences, thus being extremely easy to use. We demonstrate the effectiveness of our method in multiple-structure fitting experiments in both publicly available and in-house datasets. As shown in the experiments, our approach finds a higher number of structures containing fewer outliers compared to state-of-the-art methods. PMID:26766071

  12. MSClique: Multiple Structure Discovery through the Maximum Weighted Clique Problem.

    PubMed

    Sanroma, Gerard; Penate-Sanchez, Adrian; Alquézar, René; Serratosa, Francesc; Moreno-Noguer, Francesc; Andrade-Cetto, Juan; González Ballester, Miguel Ángel

    2016-01-01

    We present a novel approach for feature correspondence and multiple structure discovery in computer vision. In contrast to existing methods, we exploit the fact that point-sets on the same structure usually lie close to each other, thus forming clusters in the image. Given a pair of input images, we initially extract points of interest and extract hierarchical representations by agglomerative clustering. We use the maximum weighted clique problem to find the set of corresponding clusters with maximum number of inliers representing the multiple structures at the correct scales. Our method is parameter-free and only needs two sets of points along with their tentative correspondences, thus being extremely easy to use. We demonstrate the effectiveness of our method in multiple-structure fitting experiments in both publicly available and in-house datasets. As shown in the experiments, our approach finds a higher number of structures containing fewer outliers compared to state-of-the-art methods.

  13. Understanding congestion in China's medical market: an incentive structure perspective.

    PubMed

    Sun, Zesheng; Wang, Shuhong; Barnes, Stephen R

    2016-04-01

    Congestion has become one of the most important factors leading to patient dissatisfaction and doctor-patient conflicts in the medical market of China. In this study, we explore the causes and effects of structural congestion in the Chinese medical market from an incentive structure perspective. Our analysis reveals that prior medical system reforms with price regulation in China have induced hospitals to establish incentives for capital-intensive investments, while ignoring human capital, and have driven medical staff and patients to higher-level hospitals, reinforcing an incentive structure in which congestion in higher-level hospitals and idle resources in lower-level hospitals coexist. The existing incentive structure has led to cost increases and degradation of human capital and specific factor effects. Recent reforms to reduce congestion in the Chinese medical market were not effective. Most of them had no impact on and did not involve the existing distorted incentive structure. Future reforms should consider rebalancing expectations for medical quality, free flow of human capital and price regulation reforms to rebuild a new incentive structure. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  14. Mathematical theory of a relaxed design problem in structural optimization

    NASA Technical Reports Server (NTRS)

    Kikuchi, Noboru; Suzuki, Katsuyuki

    1990-01-01

    Various attempts have been made to construct a rigorous mathematical theory of optimization for size, shape, and topology (i.e. layout) of an elastic structure. If these are represented by a finite number of parametric functions, as Armand described, it is possible to construct an existence theory of the optimum design using compactness argument in a finite dimensional design space or a closed admissible set of a finite dimensional design space. However, if the admissible design set is a subset of non-reflexive Banach space such as L(sup infinity)(Omega), construction of the existence theory of the optimum design becomes suddenly difficult and requires to extend (i.e. generalize) the design problem to much more wider class of design that is compatible to mechanics of structures in the sense of variational principle. Starting from the study by Cheng and Olhoff, Lurie, Cherkaev, and Fedorov introduced a new concept of convergence of design variables in a generalized sense and construct the 'G-Closure' theory of an extended (relaxed) optimum design problem. A similar attempt, but independent in large extent, can also be found in Kohn and Strang in which the shape and topology optimization problem is relaxed to allow to use of perforated composites rather than restricting it to usual solid structures. An identical idea is also stated in Murat and Tartar using the notion of the homogenization theory. That is, introducing possibility of micro-scale perforation together with the theory of homogenization, the optimum design problem is relaxed to construct its mathematical theory. It is also noted that this type of relaxed design problem is perfectly matched to the variational principle in structural mechanics.

  15. Structural DNA Nanotechnology: State of the Art and Future Perspective

    PubMed Central

    2015-01-01

    Over the past three decades DNA has emerged as an exceptional molecular building block for nanoconstruction due to its predictable conformation and programmable intra- and intermolecular Watson–Crick base-pairing interactions. A variety of convenient design rules and reliable assembly methods have been developed to engineer DNA nanostructures of increasing complexity. The ability to create designer DNA architectures with accurate spatial control has allowed researchers to explore novel applications in many directions, such as directed material assembly, structural biology, biocatalysis, DNA computing, nanorobotics, disease diagnosis, and drug delivery. This Perspective discusses the state of the art in the field of structural DNA nanotechnology and presents some of the challenges and opportunities that exist in DNA-based molecular design and programming. PMID:25029570

  16. Structural DNA nanotechnology: state of the art and future perspective.

    PubMed

    Zhang, Fei; Nangreave, Jeanette; Liu, Yan; Yan, Hao

    2014-08-13

    Over the past three decades DNA has emerged as an exceptional molecular building block for nanoconstruction due to its predictable conformation and programmable intra- and intermolecular Watson-Crick base-pairing interactions. A variety of convenient design rules and reliable assembly methods have been developed to engineer DNA nanostructures of increasing complexity. The ability to create designer DNA architectures with accurate spatial control has allowed researchers to explore novel applications in many directions, such as directed material assembly, structural biology, biocatalysis, DNA computing, nanorobotics, disease diagnosis, and drug delivery. This Perspective discusses the state of the art in the field of structural DNA nanotechnology and presents some of the challenges and opportunities that exist in DNA-based molecular design and programming.

  17. Nonlinear Transient Problems Using Structure Compatible Heat Transfer Code

    NASA Technical Reports Server (NTRS)

    Hou, Gene

    2000-01-01

    The report documents the recent effort to enhance a transient linear heat transfer code so as to solve nonlinear problems. The linear heat transfer code was originally developed by Dr. Kim Bey of NASA Largely and called the Structure-Compatible Heat Transfer (SCHT) code. The report includes four parts. The first part outlines the formulation of the heat transfer problem of concern. The second and the third parts give detailed procedures to construct the nonlinear finite element equations and the required Jacobian matrices for the nonlinear iterative method, Newton-Raphson method. The final part summarizes the results of the numerical experiments on the newly enhanced SCHT code.

  18. Structure of Problem Recognition Questionnaire with Hispanic/Latino Adolescents.

    PubMed

    Stanforth, Evan T; McCabe, Brian E; Mena, Maite P; Santisteban, Daniel A

    2016-12-01

    Motivation is a prominent target for substance use interventions because it is theorized to increase engagement in therapy and predict treatment outcomes. Establishing the validity of measures relevant to motivation among Hispanic/Latino adolescents will improve the resources available for screening and measuring change processes in a multicultural population. We examined the structure of the Problem Recognition Questionnaire (PRQ; Cady, Winters, Jordan, Solberg, & Stinchfield, 1996) with Hispanic/Latino adolescents. Participants were adolescents (n=191) in a randomized controlled trial for substance abuse. Data were collected during a baseline pre-treatment time point and post-treatment time point that was four-months post-baseline. Confirmatory factor analysis (CFA) showed that the three-factor structure proposed by Cady et al. (1996) had a poor fit with pre-treatment data. Follow-up exploratory analyses with principal axis factoring identified an alternate three-factor structure with pre-treatment data (problem recognition, readiness, and treatment resistance). A second CFA showed this three-factor model fit data from participants at the post-treatment time point (n=155). The results provide preliminary evidence for using our proposed factor structure for the PRQ subscales with Hispanic/Latino adolescents. We discuss the dimensions we identified in the context of similar measures and the implications for measuring problem recognition, readiness, and treatment resistance. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. An Event-Based Solution to the Perspective-n-Point Problem.

    PubMed

    Reverter Valeiras, David; Kime, Sihem; Ieng, Sio-Hoi; Benosman, Ryad Benjamin

    2016-01-01

    The goal of the Perspective-n-Point problem (PnP) is to find the relative pose between an object and a camera from a set of n pairings between 3D points and their corresponding 2D projections on the focal plane. Current state of the art solutions, designed to operate on images, rely on computationally expensive minimization techniques. For the first time, this work introduces an event-based PnP algorithm designed to work on the output of a neuromorphic event-based vision sensor. The problem is formulated here as a least-squares minimization problem, where the error function is updated with every incoming event. The optimal translation is then computed in closed form, while the desired rotation is given by the evolution of a virtual mechanical system whose energy is proven to be equal to the error function. This allows for a simple yet robust solution of the problem, showing how event-based vision can simplify computer vision tasks. The approach takes full advantage of the high temporal resolution of the sensor, as the estimated pose is incrementally updated with every incoming event. Two approaches are proposed: the Full and the Efficient methods. These two methods are compared against a state of the art PnP algorithm both on synthetic and on real data, producing similar accuracy in addition of being faster.

  20. An Event-Based Solution to the Perspective-n-Point Problem

    PubMed Central

    Reverter Valeiras, David; Kime, Sihem; Ieng, Sio-Hoi; Benosman, Ryad Benjamin

    2016-01-01

    The goal of the Perspective-n-Point problem (PnP) is to find the relative pose between an object and a camera from a set of n pairings between 3D points and their corresponding 2D projections on the focal plane. Current state of the art solutions, designed to operate on images, rely on computationally expensive minimization techniques. For the first time, this work introduces an event-based PnP algorithm designed to work on the output of a neuromorphic event-based vision sensor. The problem is formulated here as a least-squares minimization problem, where the error function is updated with every incoming event. The optimal translation is then computed in closed form, while the desired rotation is given by the evolution of a virtual mechanical system whose energy is proven to be equal to the error function. This allows for a simple yet robust solution of the problem, showing how event-based vision can simplify computer vision tasks. The approach takes full advantage of the high temporal resolution of the sensor, as the estimated pose is incrementally updated with every incoming event. Two approaches are proposed: the Full and the Efficient methods. These two methods are compared against a state of the art PnP algorithm both on synthetic and on real data, producing similar accuracy in addition of being faster. PMID:27242412

  1. Teaching mathematical word problem solving: the quality of evidence for strategy instruction priming the problem structure.

    PubMed

    Jitendra, Asha K; Petersen-Brown, Shawna; Lein, Amy E; Zaslofsky, Anne F; Kunkel, Amy K; Jung, Pyung-Gang; Egan, Andrea M

    2015-01-01

    This study examined the quality of the research base related to strategy instruction priming the underlying mathematical problem structure for students with learning disabilities and those at risk for mathematics difficulties. We evaluated the quality of methodological rigor of 18 group research studies using the criteria proposed by Gersten et al. and 10 single case design (SCD) research studies using criteria suggested by Horner et al. and the What Works Clearinghouse. Results indicated that 14 group design studies met the criteria for high-quality or acceptable research, whereas SCD studies did not meet the standards for an evidence-based practice. Based on these findings, strategy instruction priming the mathematics problem structure is considered an evidence-based practice using only group design methodological criteria. Implications for future research and for practice are discussed. © Hammill Institute on Disabilities 2013.

  2. [SENS is making sense - on the way to an innovative approach to structure Palliative Care problems].

    PubMed

    Eychmüller, Steffen

    2012-02-01

    Assessment in Palliative Care is a broad field trying to integrate various dimensions from physical, psychological, social and spiritual problems and suffering. Medical diagnosis alone may not successfully reflect this multidimensional aspects, as it may be true for nursing diagnosis. In addition, any assessment procedures in palliative care needs a) to be performed in an interprofessional way, i.e. integrating various perspectives, b) to avoid additional burden for the patient, and c) to allow repetitive longitudinal follow up in order to assess the outcomes of interventions. Derived from WHO definition of Palliative Care from 2002 we developed at our centre the problem- rather than diagnosis based SENS-Model and started its clinical implementation. This new tool to structure narratives from patients may facilitate not only to prioritize the various problems, but also to define tasks and responsibilities within the team including the evaluation of the intended benefit. Apart, SENS may help to avoid medicalisation and focus on pathological rather then salutogenetic interpretation. By this, SENS may develop towards a first problem - based ";classification and assessment system" in palliative care, possibly valuable for other chronic diseases and its multidimensional problems, too.

  3. Potential structural material problems in a hydrogen energy system

    NASA Technical Reports Server (NTRS)

    Gray, H. R.; Nelson, H. G.; Johnson, R. E.; Mcpherson, B.; Howard, F. S.; Swisher, J. H.

    1975-01-01

    Potential structural material problems that may be encountered in the three components of a hydrogen energy system - production, transmission/storage, and utilization - were identified. Hydrogen embrittlement, corrosion, oxidation, and erosion may occur during the production of hydrogen. Hydrogen embrittlement is of major concern during both transmission and utilization of hydrogen. Specific materials research and development programs necessary to support a hydrogen energy system are described.

  4. Center of Gravity within the Ill-Structured Problem

    DTIC Science & Technology

    2012-05-04

    one of the most important tasks during the early stages of planning. 25 It is critical to understand that the purpose of identifying the enemy’s...train to them. Planning exercises within ill-structure problems need to be incorporated at all levels of command and training. It will do us little...theories when he said, We wanted to show that every age had its own kind of war, its own limiting conditions, and own peculiar preconceptions

  5. A structural and functional perspective of alphavirus replication and assembly

    PubMed Central

    Jose, Joyce; Snyder, Jonathan E; Kuhn, Richard J

    2009-01-01

    Alphaviruses are small, spherical, enveloped, positive-sense ssRNA viruses responsible for a considerable number of human and animal diseases. Alphavirus members include Chikungunya virus, Sindbis virus, Semliki Forest virus, the western, eastern and Venezuelan equine encephalitis viruses, and the Ross River virus. Alphaviruses can cause arthritic diseases and encephalitis in humans and animals and continue to be a worldwide threat. The viruses are transmitted by blood-sucking arthropods, and replicate in both arthropod and vertebrate hosts. Alphaviruses form spherical particles (65–70 nm in diameter) with icosahedral symmetry and a triangulation number of four. The icosahedral structures of alphaviruses have been defined to very high resolutions by cryo-electron microscopy and crystallographic studies. In this review, we summarize the major events in alphavirus infection: entry, replication, assembly and budding. We focus on data acquired from structural and functional studies of the alphaviruses. These structural and functional data provide a broader perspective of the virus lifecycle and structure, and allow additional insight into these important viruses. PMID:19722838

  6. A structural and functional perspective of alphavirus replication and assembly.

    PubMed

    Jose, Joyce; Snyder, Jonathan E; Kuhn, Richard J

    2009-09-01

    Alphaviruses are small, spherical, enveloped, positive-sense ssRNA viruses responsible for a considerable number of human and animal diseases. Alphavirus members include Chikungunya virus, Sindbis virus, Semliki Forest virus, the western, eastern and Venezuelan equine encephalitis viruses, and the Ross River virus. Alphaviruses can cause arthritic diseases and encephalitis in humans and animals and continue to be a worldwide threat. The viruses are transmitted by blood-sucking arthropods, and replicate in both arthropod and vertebrate hosts. Alphaviruses form spherical particles (65-70 nm in diameter) with icosahedral symmetry and a triangulation number of four. The icosahedral structures of alphaviruses have been defined to very high resolutions by cryo-electron microscopy and crystallographic studies. In this review, we summarize the major events in alphavirus infection: entry, replication, assembly and budding. We focus on data acquired from structural and functional studies of the alphaviruses. These structural and functional data provide a broader perspective of the virus lifecycle and structure, and allow additional insight into these important viruses.

  7. Structural patterns in Swedish health policy: a 30-year perspective.

    PubMed

    Saltman, Richard B

    2015-04-01

    This perspective reviews key institutional and organizational patterns in Swedish health care over the last 30 years, probing the roots of several complicated policy questions that concern present-day Swedish decision-makers. It explores in particular the ongoing structural tension between stability, on the one hand, and the necessary levels of innovation and dynamism demanded by the current period of major clinical, technological, economic, social and supranational (EU) change. Where useful, the article compares Swedish developments with those in the other three European Nordic countries as well as other northern European health systems. Sweden's health sector evolution can provide valuable insight for other countries into the complexity involved in re-thinking tradeoffs between policies that emphasize stability as against those that encourage innovation in health sector governance and provision.

  8. Applying simulation modeling to problems in toxicology and risk assessment--a short perspective.

    PubMed

    Andersen, M E; Clewell, H J; Frederick, C B

    1995-08-01

    The goals of this perspective have been to examine areas where quantitative simulation models may be useful in toxicology and related risk assessment fields and to offer suggestions for preparing manuscripts that describe these models. If developments in other disciplines serve as a bell-wether, the use of mathematical models in toxicology will continue to increase, partly, at least, because the new generations of scientists are being trained in an electronic environment where computation of all kinds is learned at an early age. Undoubtedly, however, the utility of these models will be directly tied to the skills of investigators in accurately describing models in their research papers. These publications should convey descriptions of both the insights obtained and the opportunities provided by these models to integrate existing data bases and suggest new and useful experiments. We hope these comments serve to facilitate the expansion of good modeling practices as applied to toxicological problems.

  9. Extended ALE Method for fluid-structure interaction problems with large structural displacements

    NASA Astrophysics Data System (ADS)

    Basting, Steffen; Quaini, Annalisa; Čanić, Sunčica; Glowinski, Roland

    2017-02-01

    Standard Arbitrary Lagrangian-Eulerian (ALE) methods for the simulation of fluid-structure interaction (FSI) problems fail due to excessive mesh deformations when the structural displacement is large. We propose a method that successfully deals with this problem, keeping the same mesh connectivity while enforcing mesh alignment with the structure. The proposed Extended ALE Method relies on a variational mesh optimization technique, where mesh alignment with the structure is achieved via a constraint. This gives rise to a constrained optimization problem for mesh optimization, which is solved whenever the mesh quality deteriorates. The performance of the proposed Extended ALE Method is demonstrated on a series of numerical examples involving 2D FSI problems with large displacements. Two-way coupling between the fluid and structure is considered in all the examples. The FSI problems are solved using either a Dirichlet-Neumann algorithm, or a Robin-Neumann algorithm. The Dirichlet-Neumann algorithm is enhanced by an adaptive relaxation procedure based on Aitken's acceleration. We show that the proposed method has excellent performance in problems with large displacements, and that it agrees well with a standard ALE method in problems with mild displacement.

  10. A Benchmark Problem for Development of Autonomous Structural Modal Identification

    NASA Technical Reports Server (NTRS)

    Pappa, Richard S.; Woodard, Stanley E.; Juang, Jer-Nan

    1996-01-01

    This paper summarizes modal identification results obtained using an autonomous version of the Eigensystem Realization Algorithm on a dynamically complex, laboratory structure. The benchmark problem uses 48 of 768 free-decay responses measured in a complete modal survey test. The true modal parameters of the structure are well known from two previous, independent investigations. Without user involvement, the autonomous data analysis identified 24 to 33 structural modes with good to excellent accuracy in 62 seconds of CPU time (on a DEC Alpha 4000 computer). The modal identification technique described in the paper is the baseline algorithm for NASA's Autonomous Dynamics Determination (ADD) experiment scheduled to fly on International Space Station assembly flights in 1997-1999.

  11. Affect and Meta-Affect in Mathematical Problem Solving: A Representational Perspective

    ERIC Educational Resources Information Center

    DeBellis, Valerie A.; Goldin, Gerald A.

    2006-01-01

    We discuss a research-based theoretical framework based on affect as an internal representational system. Key ideas include the concepts of meta-affect and affective structures, and the constructs of mathematical intimacy and mathematical integrity. We understand these as fundamental to powerful mathematical problem solving, and deserving of…

  12. Gauging the Potential of Socially Critical Environmental Education (EE): Examining Local Environmental Problems through Children's Perspective

    ERIC Educational Resources Information Center

    Tsoubaris, Dimitris; Georgopoulos, Aleksandros

    2013-01-01

    The objective of this qualitative research work is to detect the needs, aspirations and feelings of pupils experiencing local environmental problems and elaborate them through the prism of a socially critical educational approach. Semi-structured focus group interviews are used as a research method applied to four primary schools located near…

  13. Gauging the Potential of Socially Critical Environmental Education (EE): Examining Local Environmental Problems through Children's Perspective

    ERIC Educational Resources Information Center

    Tsoubaris, Dimitris; Georgopoulos, Aleksandros

    2013-01-01

    The objective of this qualitative research work is to detect the needs, aspirations and feelings of pupils experiencing local environmental problems and elaborate them through the prism of a socially critical educational approach. Semi-structured focus group interviews are used as a research method applied to four primary schools located near…

  14. Algorithmic aspects of transient heat transfer problems in structures

    NASA Technical Reports Server (NTRS)

    Haftka, R. T.; Kadivar, M. H.

    1982-01-01

    It is noted that the application of finite element or finite difference techniques to the solution of transient heat transfer problems in structures often results in a stiff system of ordinary differential equations. Such systems are usually handled most efficiently by implicit integration techniques which require the solution of large and sparse systems of algebraic equations. The assembly and solution of these systems using the incomplete Cholesky conjugate gradient algorithm is examined. Several examples are used to demonstrate the advantage of the algorithm over other techniques.

  15. The problem with determining atomic structure at the nanoscale.

    PubMed

    Billinge, Simon J L; Levin, Igor

    2007-04-27

    Emerging complex functional materials often have atomic order limited to the nanoscale. Examples include nanoparticles, species encapsulated in mesoporous hosts, and bulk crystals with intrinsic nanoscale order. The powerful methods that we have for solving the atomic structure of bulk crystals fail for such materials. Currently, no broadly applicable, quantitative, and robust methods exist to replace crystallography at the nanoscale. We provide an overview of various classes of nanostructured materials and review the methods that are currently used to study their structure. We suggest that successful solutions to these nanostructure problems will involve interactions among researchers from materials science, physics, chemistry, computer science, and applied mathematics, working within a "complex modeling" paradigm that combines theory and experiment in a self-consistent computational framework.

  16. Hierarchical Multiobjective Linear Programming Problems with Fuzzy Domination Structures

    NASA Astrophysics Data System (ADS)

    Yano, Hitoshi

    2010-10-01

    In this paper, we focus on hierarchical multiobjective linear programming problems with fuzzy domination structures where multiple decision makers in a hierarchical organization have their own multiple objective linear functions together with common linear constraints. After introducing decision powers and the solution concept based on the α-level set for the fuzzy convex cone Λ which reflects a fuzzy domination structure, we propose a fuzzy approach to obtain a satisfactory solution which reflects not only the hierarchical relationships between multiple decision makers but also their own preferences for their membership functions. In the proposed method, instead of Pareto optimal concept, a generalized Λ˜α-extreme point concept is introduced. In order to obtain a satisfactory solution from among a generalized Λ˜α-extreme point set, an interactive algorithm based on linear programming is proposed, and an interactive processes are demonstrated by means of an illustrative numerical example.

  17. Perspective: Explicitly correlated electronic structure theory for complex systems

    NASA Astrophysics Data System (ADS)

    Grüneis, Andreas; Hirata, So; Ohnishi, Yu-ya; Ten-no, Seiichiro

    2017-02-01

    The explicitly correlated approach is one of the most important breakthroughs in ab initio electronic structure theory, providing arguably the most compact, accurate, and efficient ansatz for describing the correlated motion of electrons. Since Hylleraas first used an explicitly correlated wave function for the He atom in 1929, numerous attempts have been made to tackle the significant challenges involved in constructing practical explicitly correlated methods that are applicable to larger systems. These include identifying suitable mathematical forms of a correlated wave function and an efficient evaluation of many-electron integrals. R12 theory, which employs the resolution of the identity approximation, emerged in 1985, followed by the introduction of novel correlation factors and wave function ansätze, leading to the establishment of F12 theory in the 2000s. Rapid progress in recent years has significantly extended the application range of explicitly correlated theory, offering the potential of an accurate wave-function treatment of complex systems such as photosystems and semiconductors. This perspective surveys explicitly correlated electronic structure theory, with an emphasis on recent stochastic and deterministic approaches that hold significant promise for applications to large and complex systems including solids.

  18. "Nobody Can Sit There": Two Perspectives on How Mathematics Problems in Context Mediate Group Problem Solving Discussions

    ERIC Educational Resources Information Center

    Zahner, William

    2012-01-01

    This study examines how a group of bilingual ninth grade algebra students discussed two word problems stated in terms of "real life" contexts. Using a lens of mediated action (Wertsch, 1998), the analysis reveals two distinct ways that the problem contexts influenced the group's mathematical reasoning. In one problem, the problem context…

  19. Rethinking policy perspectives on childhood stunting: time to formulate a structural and multifactorial strategy

    PubMed Central

    Mejía‐Guevara, Iván; Krishna, Aditi

    2016-01-01

    Abstract Stunting and chronic undernutrition among children in South Asia remain a major unresolved global health issue. There are compelling intrinsic and moral reasons to ensure that children attain their optimal growth potential facilitated via promotion of healthy living conditions. Investments in efforts to ensure that children's growth is not faltered also have substantial instrumental benefits in terms of cognitive and economic development. Using the case of India, we critique three prevailing approaches to reducing undernutrition among children: an over‐reliance on macroeconomic growth as a potent policy instrument, a disproportionate focus on interpreting undernutrition as a demand‐side problem and an over‐reliance on unintegrated single‐factorial (one at a time) approaches to policy and research. Using existing evidence, we develop a case for support‐led policy approach with a focus on integrated and structural factors to addressing the problem of undernutrition among children in India. Key messages Eliminating child undernutrition is important from an intrinsic perspective and offers considerable instrumental benefits to individual and society.Evidence suggests that an exclusive reliance on a growth‐mediated strategy to eliminate stunting needs to be reconsidered, suggesting the need for a substantial support‐led strategy.Interpreting and addressing undernutrition as a demand‐side problem with proximal single‐factorial interventions is futile.There is an urgent need to develop interventions that address the broader structural and upstream causes of child undernutrition. PMID:27187918

  20. Recent advances, trends and new perspectives via enthalpy-based finite element formulations for applications to solidification problems

    NASA Technical Reports Server (NTRS)

    Tamma, Kumar K.; Namburu, Raju R.

    1990-01-01

    The present paper describes recent advances and trends in finite element developments and applications for solidification problems. In particular, in comparison to traditional methods of approach, new enthalpy-based architectures based on a generalized trapezoidal family of representations are presented which provide different perspectives, physical interpretation and solution architectures for effective numerical simulation of phase change processes encountered in solidification problems. Various numerical test models are presented and the results support the proposition for employing such formulations for general phase change applications.

  1. Recent advances, trends and new perspectives via enthalpy-based finite element formulations for applications to solidification problems

    NASA Technical Reports Server (NTRS)

    Tamma, Kumar K.; Namburu, Raju R.

    1990-01-01

    The present paper describes recent advances and trends in finite element developments and applications for solidification problems. In particular, in comparison to traditional methods of approach, new enthalpy-based architectures based on a generalized trapezoidal family of representations are presented which provide different perspectives, physical interpretation and solution architectures for effective numerical simulation of phase change processes encountered in solidification problems. Various numerical test models are presented and the results support the proposition for employing such formulations for general phase change applications.

  2. Employability Skills, Personal Qualities, and Early Employment Problems of Entry-Level Auditors: Perspectives from Employers, Lecturers, Auditors, and Students

    ERIC Educational Resources Information Center

    Lim, Yet-Mee; Lee, Teck Heang; Yap, Ching Seng; Ling, Chui Ching

    2016-01-01

    The authors examine the issue of employability of university accounting students from the perspectives of accounting firm employers, junior auditors, accounting lecturers, and accounting students. Areas of investigation include perceived importance of employability skills and desirable personal qualities; and early employment problems encountered…

  3. Employability Skills, Personal Qualities, and Early Employment Problems of Entry-Level Auditors: Perspectives from Employers, Lecturers, Auditors, and Students

    ERIC Educational Resources Information Center

    Lim, Yet-Mee; Lee, Teck Heang; Yap, Ching Seng; Ling, Chui Ching

    2016-01-01

    The authors examine the issue of employability of university accounting students from the perspectives of accounting firm employers, junior auditors, accounting lecturers, and accounting students. Areas of investigation include perceived importance of employability skills and desirable personal qualities; and early employment problems encountered…

  4. Time-limited, structured youth mentoring and adolescent problem behaviors.

    PubMed

    Weiler, Lindsey M; Haddock, Shelley A; Zimmerman, Toni S; Henry, Kimberly L; Krafchick, Jennifer L; Youngblade, Lise M

    2015-10-01

    Youth mentoring can have a profound impact on the lives of high-risk youth. This study presents the Campus Corps program, a time-limited (12-week), structured mentoring program for high-risk youth (ages 11-18), and results from a quasi-experimental pilot evaluation. Baseline and post-intervention problem behavior data from 315 offending youth were used in multiple regression analyses. After accounting for baseline group differences, pre-intervention scores, and demographic covariates, Campus Corps participants (n=187, 63.1% male) reported less engagement in problem behavior, lower acceptance of problem behavior, and greater sense of autonomy from marijuana use post-intervention than participants in the comparison condition (n=128, 66.4% male). Conversely, post-intervention group differences were not observed for peer refusal skills or autonomy from alcohol use. A description of the Campus Corps program design and supplemental preliminary findings contribute to the growing knowledge base of youth mentoring program designs and outcomes.

  5. Time-limited, structured youth mentoring and adolescent problem behaviors

    PubMed Central

    Haddock, Shelley A.; Zimmerman, Toni S.; Henry, Kimberly L.; Krafchick, Jennifer L.; Youngblade, Lise M.

    2015-01-01

    Youth mentoring can have a profound impact on the lives of high-risk youth. This study presents the Campus Corps program, a time-limited (12-week), structured mentoring program for high-risk youth (ages 11–18), and results from a quasi-experimental pilot evaluation. Baseline and post-intervention problem behavior data from 315 offending youth were used in multiple regression analyses. After accounting for baseline group differences, pre-intervention scores, and demographic covariates, Campus Corps participants (n=187, 63.1% male) reported less engagement in problem behavior, lower acceptance of problem behavior, and greater sense of autonomy from marijuana use post-intervention than participants in the comparison condition (n=128, 66.4% male). Conversely, post-intervention group differences were not observed for peer refusal skills or autonomy from alcohol use. A description of the Campus Corps program design and supplemental preliminary findings contribute to the growing knowledge base of youth mentoring program designs and outcomes. PMID:26640362

  6. On path-following methods for structural failure problems

    NASA Astrophysics Data System (ADS)

    Stanić, Andjelka; Brank, Boštjan; Korelc, Jože

    2016-08-01

    We revisit the consistently linearized path-following method that can be applied in the nonlinear finite element analysis of solids and structures in order to compute a solution path. Within this framework, two constraint equations are considered: a quadratic one (that includes as special cases popular spherical and cylindrical forms of constraint equation), and another one that constrains only one degree-of-freedom (DOF), the critical DOF. In both cases, the constrained DOFs may vary from one solution increment to another. The former constraint equation is successful in analysing geometrically nonlinear and/or standard inelastic problems with snap-throughs, snap-backs and bifurcation points. However, it cannot handle problems with the material softening that are computed e.g. by the embedded-discontinuity finite elements. This kind of problems can be solved by using the latter constraint equation. The plusses and minuses of the both presented constraint equations are discussed and illustrated on a set of numerical examples. Some of the examples also include direct computation of critical points and branch switching. The direct computation of the critical points is performed in the framework of the path-following method by using yet another constraint function, which is eigenvector-free and suited to detect critical points.

  7. REVIEWS OF TOPICAL PROBLEMS: 21st century: what is life from the perspective of physics?

    NASA Astrophysics Data System (ADS)

    Ivanitskii, Genrikh R.

    2010-07-01

    The evolution of the biophysical paradigm over 65 years since the publication in 1944 of Erwin Schrödinger's What is Life? The Physical Aspects of the Living Cell is reviewed. Based on the advances in molecular genetics, it is argued that all the features characteristic of living systems can also be found in nonliving ones. Ten paradoxes in logic and physics are analyzed that allow defining life in terms of a spatial-temporal hierarchy of structures and combinatory probabilistic logic. From the perspective of physics, life can be defined as resulting from a game involving interactions of matter one part of which acquires the ability to remember the success (or failure) probabilities from the previous rounds of the game, thereby increasing its chances for further survival in the next round. This part of matter is currently called living matter.

  8. Reconsideration of Plant Morphological Traits: From a Structure-Based Perspective to a Function-Based Evolutionary Perspective.

    PubMed

    Bai, Shu-Nong

    2017-01-01

    This opinion article proposes a novel alignment of traits in plant morphogenesis from a function-based evolutionary perspective. As a member species of the ecosystem on Earth, we human beings view our neighbor organisms from our own sensing system. We tend to distinguish forms and structures (i.e., "morphological traits") mainly through vision. Traditionally, a plant was considered to be consisted of three parts, i.e., the shoot, the leaves, and the root. Based on such a "structure-based perspective," evolutionary analyses or comparisons across species were made on particular parts or their derived structures. So far no conceptual framework has been established to incorporate the morphological traits of all three land plant phyta, i.e., bryophyta, pteridophyta and spermatophyta, for evolutionary developmental analysis. Using the tenets of the recently proposed concept of sexual reproduction cycle, the major morphological traits of land plants can be aligned into five categories from a function-based evolutionary perspective. From this perspective, and the resulting alignment, a new conceptual framework emerges, called "Plant Morphogenesis 123." This framework views a plant as a colony of integrated plant developmental units that are each produced via one life cycle. This view provided an alternative perspective for evolutionary developmental investigation in plants.

  9. Reconsideration of Plant Morphological Traits: From a Structure-Based Perspective to a Function-Based Evolutionary Perspective

    PubMed Central

    Bai, Shu-Nong

    2017-01-01

    This opinion article proposes a novel alignment of traits in plant morphogenesis from a function-based evolutionary perspective. As a member species of the ecosystem on Earth, we human beings view our neighbor organisms from our own sensing system. We tend to distinguish forms and structures (i.e., “morphological traits”) mainly through vision. Traditionally, a plant was considered to be consisted of three parts, i.e., the shoot, the leaves, and the root. Based on such a “structure-based perspective,” evolutionary analyses or comparisons across species were made on particular parts or their derived structures. So far no conceptual framework has been established to incorporate the morphological traits of all three land plant phyta, i.e., bryophyta, pteridophyta and spermatophyta, for evolutionary developmental analysis. Using the tenets of the recently proposed concept of sexual reproduction cycle, the major morphological traits of land plants can be aligned into five categories from a function-based evolutionary perspective. From this perspective, and the resulting alignment, a new conceptual framework emerges, called “Plant Morphogenesis 123.” This framework views a plant as a colony of integrated plant developmental units that are each produced via one life cycle. This view provided an alternative perspective for evolutionary developmental investigation in plants. PMID:28360919

  10. Intriguing structures in iterative maps motivated by N-body problem

    NASA Astrophysics Data System (ADS)

    Mittal, Ashok Kumar; Gupta, Ashok Kumar

    2011-03-01

    Conventional approaches to modeling any system try to incorporate increasingly realistic features into the model, thereby making it more and more complex. An opposite approach seeks to build simpler and simpler conceptual models capable of capturing some observed features of a system. This trend began with Lorenz, who simplified models of the atmosphere to obtain the Lorenz model consisting of a system of only three equations. Despite the simplicity of these equations, this system displayed surprisingly rich properties, and has been used as a conceptual model in diverse disciplines. Poincare maps help study ordinary differential equations from a qualitative perspective. Several investigators like Henon and Feigenbaum followed this simplification approach. Instead of investigating Poincare maps of realistic systems, they, along with several others, investigated simple maps for their own sake. Despite lack of realism, this approach proved to be very fruitful. A map, as simple as the Logistic map, became an important conceptual modeling paradigm. It provided a tool for understanding bifurcation routes to chaos, which were verified experimentally through various experiments in diverse fields. Coupled map lattices (CML) help explore partial differential equations (PDE). Further simplification led to the introduction of Cellular Automata (CA). These fields continue to be explored with vigor and have given rise to a rich body of knowledge, conceptually useful over a wide spectrum of disciplines. In this paper, we follow the simplification approach for modeling the N-body problem. N-body simulations, say in Gravitation, give rise to filamentary structures. Such structures are observed in the actual observed Galactic distribution. The mechanism for creation of such structures is not well understood. We present a simple iterative dynamical model, motivated by the N-body problem, which, though unrealistic, produces such filamentary structures. This model also exhibits a

  11. The Influence of Family Structure, the TPH2 G-703T and the 5-HTTLPR Serotonergic Genes upon Affective Problems in Children Aged 10-14 Years

    ERIC Educational Resources Information Center

    Nobile, Maria; Rusconi, Marianna; Bellina, Monica; Marino, Cecilia; Giorda, Roberto; Carlet, Ombretta; Vanzin, Laura; Molteni, Massimo; Battaglia, Marco

    2009-01-01

    Background: Both genetic and psychosocial risk factors influence the risk for depression in development. While the impacts of family structure and of serotonergic polymorphisms upon individual differences for affective problems have been investigated separately, they have never been considered together in a gene-environment interplay perspective.…

  12. The Influence of Family Structure, the TPH2 G-703T and the 5-HTTLPR Serotonergic Genes upon Affective Problems in Children Aged 10-14 Years

    ERIC Educational Resources Information Center

    Nobile, Maria; Rusconi, Marianna; Bellina, Monica; Marino, Cecilia; Giorda, Roberto; Carlet, Ombretta; Vanzin, Laura; Molteni, Massimo; Battaglia, Marco

    2009-01-01

    Background: Both genetic and psychosocial risk factors influence the risk for depression in development. While the impacts of family structure and of serotonergic polymorphisms upon individual differences for affective problems have been investigated separately, they have never been considered together in a gene-environment interplay perspective.…

  13. Consumption, Ecological Footprints and Global Inequality: A Lesson in Individual and Structural Components of Environmental Problems

    ERIC Educational Resources Information Center

    Obach, Brian K.

    2009-01-01

    As evidence of the growing ecological crisis mounts, it is imperative that sociologists speak to this social problem and incorporate a sociological perspective on environmental issues into the curriculum. Central to understanding how social issues relate to environmental problems is an examination of the ties between consumption and its ecological…

  14. Consumption, Ecological Footprints and Global Inequality: A Lesson in Individual and Structural Components of Environmental Problems

    ERIC Educational Resources Information Center

    Obach, Brian K.

    2009-01-01

    As evidence of the growing ecological crisis mounts, it is imperative that sociologists speak to this social problem and incorporate a sociological perspective on environmental issues into the curriculum. Central to understanding how social issues relate to environmental problems is an examination of the ties between consumption and its ecological…

  15. Problems Approaches to the Social Studies: Alternative Structures for an Introductory Course.

    ERIC Educational Resources Information Center

    Downey, Matthew T.

    The three problems approaches outlined for an introductory, interdisciplinary course provide opportunities to apply the methodological tools and perspectives of the social studies. Organization of each course, advantages and disadvantages, unique objectives, approaches, and methodology for a social problem approach, case study approach, and a…

  16. Potentials and problems in space applications of smart structures technology

    NASA Astrophysics Data System (ADS)

    Eaton, D. C.; Bashford, D. P.

    1994-09-01

    The well known addage 'don't run before you can walk emerging materials. It typically takes ten years before a material is sufficiently well characterized for commercial aerospace application. Much has to be learnt not only about the material properties and their susceptibility to the effects of their working environment but also about the manufacturing process and the most effective configuration related application. No project will accept a product which has no proven reliability and attractive cost effectiveness in its application. The writers firmly believe that smart structures and their related technologies must follow a similar development pattern. Indeed, faced with a range of interdisciplinary problems it seems likely that 'partially smart' techniques may well be the first applications. These will place emphasis on the more readily realizable features for any structural application. Prior use may well have been achieved in other engineering sectors. Because ground based applications are more readily accessible to check and maintain, these are generally the front runners of smart technology usage. Nevertheless, there is a strong potential for the use of smart techniques in space applications if their capabilities can be advantageously introduced when compared with traditional solutions. This paper endeavors to give a critical appraisal of the possibilities and the accompanying problems. A sample overview of related developing space technology is included. The reader is also referred to chapters 90 to 94 in ESA's Structural Materials Handbook (ESA PSS 03 203, issue 1.). It is envisaged that future space applications may include the realization and maintenance of large deployable reflector profiles, the dimensional stability of optical payloads, active noise and vibration control and in orbit health monitoring and control for largely unmanned spacecraft. The possibility of monitoring the health of items such as large cryogenic fuel tanks is a typical longer

  17. CALL FOR PAPERS: Special issue on the random search problem: trends and perspectives

    NASA Astrophysics Data System (ADS)

    da Luz, Marcos G. E.; Grosberg, Alexander Y.; Raposo, Ernesto P.; Viswanathan, Gandhi M.

    2008-11-01

    field. The subject can be approached from the perspective of different fields: ecology, networks, transport problems, molecular biology, etc. The study of the problem is particularly suited to the concepts and methods of statistical physics and stochastic processes; for example, fractals, random walks, anomalous diffusion. Discrete landscapes can be approached via graph theory, random lattices and complex networks. Such topics are regularly discussed in Journal of Physics A: Mathematical and Theoretical. All such aspects of the problem fall within the scope and focus of this special issue on the random search problem: trends and perspectives. Editorial policy All contributions to the special issue will be refereed in accordance with the refereeing policy of the journal. In particular, all research papers will be expected to be original work reporting substantial new results. The issue will also contain a number of review articles by invitation only. The Guest Editors reserve the right to judge whether a contribution fits the scope of the special issue. Guidelines for preparation of contributions We aim to publish the special issue in August 2009. To realize this, the DEADLINE for contributed papers is 15 January 2009. There is a page limit of 15 printed pages (approximately 9000 words) per contribution. For papers exceeding this limit, the Guest Editors reserve the right to request a reduction in length. Further advice on document preparation can be found at www.iop.org/Journals/jphysa. Contributions to the special issue should if possible be submitted electronically by web upload at www.iop.org/Journals/jphysa, or by email to jphysa@iop.org, quoting 'J. Phys. A Special Issue— Random Search Problem'. Please state whether the paper has been invited or is contributed. Submissions should ideally be in standard LaTeX form. Please see the website for further information on electronic submissions. Authors unable to submit electronically may send hard-copy contributions to

  18. Topographic mapping of oral structures - problems and applications in prosthodontics

    NASA Astrophysics Data System (ADS)

    Young, John M.; Altschuler, Bruce R.

    1981-10-01

    The diagnosis and treatment of malocclusion, and the proper design of restorations and prostheses, requires the determination of surface topography of the teeth and related oral structures. Surface contour measurements involve not only affected teeth, but adjacent and opposing surface contours composing a complexly interacting occlusal system. No a priori knowledge is predictable as dental structures are largely asymmetrical, non-repetitive, and non-uniform curvatures in 3-D space. Present diagnosis, treatment planning, and fabrication relies entirely on the generation of physical replicas during each stage of treatment. Fabrication is limited to materials that lend themselves to casting or coating, and to hand fitting and finishing. Inspection is primarily by vision and patient perceptual feedback. Production methods are time-consuming. Prostheses are entirely custom designed by manual methods, require costly skilled technical labor, and do not lend themselves to centralization. The potential improvement in diagnostic techniques, improved patient care, increased productivity, and cost-savings in material and man-hours that could result, if rapid and accurate remote measurement and numerical (automated) fabrication methods were devised, would be significant. The unique problems of mapping oral structures, and specific limitations in materials and methods, are reviewed.

  19. Debates—Perspectives on socio-hydrology: Changing water systems and the "tyranny of small problems"—Socio-hydrology

    NASA Astrophysics Data System (ADS)

    Sivapalan, Murugesu

    2015-06-01

    We are well and truly in the Anthropocene. Humans can no longer be considered as mere external drivers or boundary conditions in the hydrologic systems we study. The interactions and feedbacks between human actions and water cycle dynamics on the planet, combined with the evolution of human norms/values in relation to water, are throwing up a range of emergent "big problems." Understanding and offering sustainable solutions to these "big problems" require a broadening of hydrologic science to embrace the perspectives of both social and natural scientists. The new science of socio-hydrology was introduced with this in mind, yet faces major challenges due to the wide gulf that separates the knowledge foundations and methodologies of natural and social sciences. Yet, the benefits of working together are enormous, including through adoption of natural science methods for social science problems, and vice versa. Bringing together the perspectives of both social and natural scientists dealing with water is good for hydrologic science, having the salutary effect of revitalizing it as use-inspired basic science. It is good for management too, in that the broader, holistic perspectives provided by socio-hydrology can help recognize potential "big" problems that may otherwise be unforeseen and, equally, identify potential "alternative" solutions to otherwise intractable problems.

  20. Resolving defence mechanisms: A perspective based on dissipative structure theory.

    PubMed

    Zhang, Wei; Guo, Ben-Yu

    2017-04-01

    Theories and classifications of defence mechanisms are not unified. This study addresses the psychological system as a dissipative structure which exchanges information with the external and internal world. When using defence mechanisms, the cognitive-affective schema of an individual could remain stable and ordered by excluding psychological entropy, obtaining psychological negentropy or by dissipating the energy of self-presentation. From this perspective, defences can be classified into three basic types: isolation, compensation and self-dissipation. However, not every kind of defence mechanisms can actually help the individual. Non-adaptive defences are just functioning as an effective strategy in the short run but can be a harmful approach in the long run, while adaptive defences could instead help the individual as a long-term mechanism. Thus, we would like to suggest that it is more useful for the individual to use more adaptive defence mechanisms and seek out social or interpersonal support when undergoing psychic difficulties. As this model of defences is theoretical at present, we therefore aim to support and enrich this viewpoint with empirical evidence. Copyright © 2017 Institute of Psychoanalysis.

  1. [Factorial structure and reliability of Zimbardo Time Perspective Inventory].

    PubMed

    Díaz-Morales, Juan Francisco

    2006-08-01

    Time orientation is a fundamental psychological variable, what it flows all aspects of human behaviour. Past, present, and future orientation decomposed of allocated into different temporal frames the continual flow of behaviour, providing meaning and coherence. It has been proposed the Zimbardo Time Perspective Inventory (ZTPI) so multidimensional measure of time orientation, which include positive and negative evaluation of past and present, as well as future evaluation. The factorial structure and reliability of ZTPI was analysed on Spanish adult population. The participants were 756 adults with age range 19-67 years old ( M = 40.1, SD = 15.45). The principal components analyses showed five factors, very similar to obtain on nort-american undergraduate samples, even thought a little difference in composition of the present-fatalist factor. The reliability of each factor was suitable. Age and gender differences analysis showed that older groups were more future oriented and less present hedonist, female were high orientation to past negative, past positive and present fatalist, while young females were more future oriented than older females.

  2. Indoor climate problems in day institutions for children. Practical, Administrative and policy perspectives.

    PubMed

    Steensberg, J

    1985-01-01

    Based on case material from the late 1970s and early 1980s from the Institution of Medical Officers of Health covering a Danish county some examples of practical indoor climate problems in day institutions for children are given. Insufficient ventilation of premises is probably the single most important factor in the development of indoor climate problems. An effective cleaning generally improves the indoor air. The study particularly illustrates the administrative and policy perspectives of the decision making process. Those that make decisions on indoor climate problems unfortunately seem to favour a narrow definition of health, i.e. the absence of overt disease; and they are not always aware that the relationship between indoor climate factors and health effects cannot be proven in an absolute sense. Experts on the scientific aspects are needed but their statements are influenced by personal values and their perception of the reasonable balance between health protection and social costs. One of the main factors influencing the indoor climate situation in Danish day institutions for children has been the lack of an adequate regulatory framework; and the central administration and responsible ministers have failed to use the already existing legislative powers to prevent problems. Decision making in cases on the indoor climate of institutions should be accelerated; we cannot wait for proof before taking preventive measures. The indoor air of institutions is a "public good" to the same extent as the ambient air and the responsible authorities have an obligation to regulate accordingly. When building regulations prove insufficient other central authorities must support local decision makers with more specific directions. Testing of building materials, hazard rating and an approval system is needed. Guidelines on indoor climate requirements for public institutions should be developed. In countries with a built-up system of child institutions and a decreasing birth

  3. Visualizing the Structure of Medical Informatics Using Term Co-Occurrence Analysis: II. INSPEC Perspective.

    ERIC Educational Resources Information Center

    Morris, Theodore

    2001-01-01

    Term co-occurrence analysis of INSPEC classification codes and thesaurus terms used to index Medical Informatics literature reveals an information science and technology perspective on the field, to accompany the biomedical perspective previously reported. This study continues the search for a better understanding of the structure of Medical…

  4. Visualizing the Structure of Medical Informatics Using Term Co-Occurrence Analysis: II. INSPEC Perspective.

    ERIC Educational Resources Information Center

    Morris, Theodore

    2001-01-01

    Term co-occurrence analysis of INSPEC classification codes and thesaurus terms used to index Medical Informatics literature reveals an information science and technology perspective on the field, to accompany the biomedical perspective previously reported. This study continues the search for a better understanding of the structure of Medical…

  5. An Introduction to the Problem of Dynamic Structural Damping,

    DTIC Science & Technology

    1978-01-01

    ntroduction to the Problem of D~ynamic Structural Damping 4 - antini, astellani ~~~ n j ifl . fE B 22 1978 II NATO OTAN ()~ v c ~~—~~ —~7 RUE...F(s) J where: B ,, — m , s2 +c , s + k , — m~s 2 + (c, , +c ) s + k ~_ 1 +k , for i> I- — ~~~~~ — (C1 a + k,) all other B , = 0 for 1* Si ~y using...Ithys simple cover sandwich c~~er viscoelast c material iO~ iO _2 ‘ ~ j -1 - . ~~ - Fig. 3’.— Damping ratio for some materials E~ (N~t 2) a) b ) T(’C) O

  6. Symplectic structures related with higher order variational problems

    NASA Astrophysics Data System (ADS)

    Kijowski, Jerzy; Moreno, Giovanni

    2015-06-01

    In this paper, we derive the symplectic framework for field theories defined by higher order Lagrangians. The construction is based on the symplectic reduction of suitable spaces of iterated jets. The possibility of reducing a higher order system of partial differential equations to a constrained first-order one, the symplectic structures naturally arising in the dynamics of a first-order Lagrangian theory, and the importance of the Poincaré-Cartan form for variational problems, are all well-established facts. However, their adequate combination corresponding to higher order theories is missing in the literature. Here we obtain a consistent and truly finite-dimensional canonical formalism, as well as a higher order version of the Poincaré-Cartan form. In our exposition, the rigorous global proofs of the main results are always accompanied by their local coordinate descriptions, indispensable to work out practical examples.

  7. Global structure of the multiverse and the measure problem

    NASA Astrophysics Data System (ADS)

    Vilenkin, Alexander

    2013-02-01

    An unresolved question in inflationary cosmology is the assignment of probabilities to different types of events that can occur in the eternally inflating multiverse. We explore the possibility that the resolution of this "measure problem" may rely on non-standard dynamics in regions of high curvature. In particular, "big crunch" singularities that develop in bubbles with negative vacuum energy density may lead to bounces, where contraction is replaced by inflationary expansion. Similarly, singularities inside of black holes might be gateways to other inflating vacua. This would drastically affect the global structure of the multiverse. We consider a measure based on a probe geodesic which undergoes an infinite number of passages through crunches. This can be thought of as the world-line of an eternal "watcher", collecting data in an orderly fashion. This watcher's measure is independent of initial conditions and does not suffer from ambiguities associated with the choice of a cut-off surface.

  8. Perspectives of Urban Corner Store Owners and Managers on Community Health Problems and Solutions

    PubMed Central

    Young, Candace R.; Cannuscio, Carolyn C.; Karpyn, Allison; Kounaves, Sarah; Strupp, Emily; McDonough, Kevin; Shea, Judy A.

    2016-01-01

    Introduction Urban corner store interventions have been implemented to improve access to and promote purchase of healthy foods. However, the perspectives of store owners and managers, who deliver and shape these interventions in collaboration with nonprofit, government, and academic partners, have been largely overlooked. We sought to explore the views of store owners and managers on the role of their stores in the community and their beliefs about health problems and solutions in the community. Methods During 2013 and 2014, we conducted semistructured, in-depth interviews in Philadelphia, Pennsylvania, and Camden, New Jersey, with 23 corner store owners/managers who participated in the Healthy Corner Store Initiative spearheaded by The Food Trust, a nonprofit organization focused on food access in low-income communities. We oversampled high-performing store owners. Results Store owners/managers reported that their stores served multiple roles, including providing a convenient source of goods, acting as a community hub, supporting community members, working with neighborhood schools, and improving health. Owners/managers described many challenging aspects of running a small store, including obtaining high-quality produce at a good price and in small quantities. Store owners/managers believed that obesity, diabetes, high cholesterol, and poor diet are major problems in their communities. Some owners/managers engaged with customers to discuss healthy behaviors. Conclusion Our findings suggest that store owners and managers are crucial partners for healthy eating interventions. Corner store owners/managers interact with community members daily, are aware of community health issues, and are community providers of access to food. Corner store initiatives can be used to implement innovative programs to further develop the untapped potential of store owners/managers. PMID:27736054

  9. Interactions in Bacterial Biofilm Development: A Structural Perspective

    PubMed Central

    Garnett, James A; Matthews, Steve

    2012-01-01

    A community-based life style is the normal mode of growth and survival for many bacterial species. These cellular accretions or biofilms are initiated upon recognition of solid phases by cell surface exposed adhesive moieties. Further cell-cell interactions, cell signalling and bacterial replication leads to the establishment of dense populations encapsulated in a mainly self-produced extracellular matrix; this comprises a complex mixture of macromolecules. These fascinating architectures protect the inhabitants from radiation damage, dehydration, pH fluctuations and antimicrobial compounds. As such they can cause bacterial persistence in disease and problems in industrial applications. In this review we discuss the current understandings of these initial biofilm-forming processes based on structural data. We also briefly describe latter biofilm maturation and dispersal events, which although lack high-resolution insights, are the present focus for many structural biologists working in this field. Finally we give an overview of modern techniques aimed at preventing and disrupting problem biofilms. PMID:23305361

  10. Barriers and Facilitators of Responding to Problem Gambling: Perspectives from Australian Mental Health Services.

    PubMed

    Rodda, S N; Manning, V; Dowling, N A; Lee, S J; Lubman, D I

    2017-09-07

    Despite high rates of comorbidity between problem gambling and mental health disorders, few studies have examined barriers or facilitators to the implementation of screening for problem gambling in mental health services. This exploratory qualitative study identified key themes associated with screening in mental health services. Semi-structured interviews were undertaken with 30 clinicians and managers from 11 mental health services in Victoria, Australia. Major themes and subthemes were identified using qualitative content analysis. Six themes emerged including competing priorities, importance of routine screening, access to appropriate screening tools, resources, patient responsiveness and workforce development. Barriers to screening included a focus on immediate risk as well as gambling being often considered as a longer-term concern. Clinicians perceived problem gambling as a relatively rare condition, but did acknowledge the need for brief screening. Facilitators to screening were changes to system processes, such as identification of an appropriate brief screening instrument, mandating its use as part of routine screening, as well as funded workforce development activities in the identification and management of problem gambling.

  11. Research Projects in Physics: A Mechanism for Teaching Ill-Structured Problem Solving

    NASA Astrophysics Data System (ADS)

    Milbourne, Jeff; Bennett, Jonathan

    2017-10-01

    Physics education research has a tradition of studying problem solving, exploring themes such as physical intuition and differences between expert and novice problem solvers. However, most of this work has focused on traditional, or well-structured, problems, similar to what might appear in a textbook. Less work has been done with open-ended, or ill-structured, problems, similar to the types of problems students might face in their professional lives. Given the national discourse on educational system reform aligned with 21st century skills, including problem solving, it is critical to provide educational experiences that help students learn to solve all types of problems, including ill-structured problems.

  12. Gas phase structures of peroxides: experiments and computational problems.

    PubMed

    Oberhammer, Heinz

    2015-02-02

    Gas-phase structures of several organic and inorganic peroxides X-O-O-X and X-O-O-X', which have been determined experimentally by gas electron diffraction and/or microwave spectroscopy, are discussed. The OO bond length in these peroxides varies from 1.481(8) Å in Me3 SiOOSiMe3 to 1.214(2) Å in FOOF and the dihedral angle ϕ(XO-OX) between 0° in HC(O)O-OH and near 180° in Bu(t) O-OBu(t) . Some of the peroxides cause problems for quantum chemistry, since several computational methods fail to reproduce the experimental structures. Extreme examples are MeO-OMe and FO-OF. In the case of MeO-OMe only about half of the more than 100 computational methods reported in the literature reproduce the experimentally determined double-minimum shape of the torsional potential around the OO bond correctly. For FO-OF only a small number of close to 200 computational methods reproduce the OO and OF bond lengths better than ±0.02 Å.

  13. Solving Optimal Control Problems by Exploiting Inherent Dynamical Systems Structures

    NASA Astrophysics Data System (ADS)

    Flaßkamp, Kathrin; Ober-Blöbaum, Sina; Kobilarov, Marin

    2012-08-01

    Computing globally efficient solutions is a major challenge in optimal control of nonlinear dynamical systems. This work proposes a method combining local optimization and motion planning techniques based on exploiting inherent dynamical systems structures, such as symmetries and invariant manifolds. Prior to the optimal control, the dynamical system is analyzed for structural properties that can be used to compute pieces of trajectories that are stored in a motion planning library. In the context of mechanical systems, these motion planning candidates, termed primitives, are given by relative equilibria induced by symmetries and motions on stable or unstable manifolds of e.g. fixed points in the natural dynamics. The existence of controlled relative equilibria is studied through Lagrangian mechanics and symmetry reduction techniques. The proposed framework can be used to solve boundary value problems by performing a search in the space of sequences of motion primitives connected using optimized maneuvers. The optimal sequence can be used as an admissible initial guess for a post-optimization. The approach is illustrated by two numerical examples, the single and the double spherical pendula, which demonstrates its benefit compared to standard local optimization techniques.

  14. Sparse Solution of High-Dimensional Model Calibration Inverse Problems under Uncertainty in Prior Structural Connectivity

    NASA Astrophysics Data System (ADS)

    Mohammad khaninezhad, M.; Jafarpour, B.

    2012-12-01

    Data limitation and heterogeneity of the geologic formations introduce significant uncertainty in predicting the related flow and transport processes in these environments. Fluid flow and displacement behavior in subsurface systems is mainly controlled by the structural connectivity models that create preferential flow pathways (or barriers). The connectivity of extreme geologic features strongly constrains the evolution of the related flow and transport processes in subsurface formations. Therefore, characterization of the geologic continuity and facies connectivity is critical for reliable prediction of the flow and transport behavior. The goal of this study is to develop a robust and geologically consistent framework for solving large-scale nonlinear subsurface characterization inverse problems under uncertainty about geologic continuity and structural connectivity. We formulate a novel inverse modeling approach by adopting a sparse reconstruction perspective, which involves two major components: 1) sparse description of hydraulic property distribution under significant uncertainty in structural connectivity and 2) formulation of an effective sparsity-promoting inversion method that is robust against prior model uncertainty. To account for the significant variability in the structural connectivity, we use, as prior, multiple distinct connectivity models. For sparse/compact representation of high-dimensional hydraulic property maps, we investigate two methods. In one approach, we apply the principle component analysis (PCA) to each prior connectivity model individually and combine the resulting leading components from each model to form a diverse geologic dictionary. Alternatively, we combine many realizations of the hydraulic properties from different prior connectivity models and use them to generate a diverse training dataset. We use the training dataset with a sparsifying transform, such as K-SVD, to construct a sparse geologic dictionary that is robust to

  15. Children's Use of Feature Descriptions to Solve Spatial Perspective and Rotation Problems.

    ERIC Educational Resources Information Center

    Ives, S.W.; Rakow, J.

    1983-01-01

    Among young children, verbalization led to many correct responses on a spatial perspective task (indicating views of an object from different positions), but produced few correct responses in a rotation task (imagining different views of a rotating object). Results suggested that language enhances perspective task performance by allowing feature…

  16. Summer Sessions in Colleges and Universities: Perspectives, Practices, Problems, and Prospects.

    ERIC Educational Resources Information Center

    Young, Raymond J.; McDougall, William P.

    This book offers normative information about various operational facets of collegiate summer activities, places the role of the modern day collegiate summer session in evolutionary perspective, and provides baseline information produced by four national studies and one regional study. The book's chapters focus on: (1) a global perspective and…

  17. Introduction to the special issue on aquifer-sedimentology: problems, perspectives and modern approaches

    NASA Astrophysics Data System (ADS)

    Huggenberger, Peter; Aigner, Tom

    1999-12-01

    Progress towards a better understanding of groundwater circulation and transport processes in aquifers demands a multidisciplinary approach to a host of unresolved problems. Although much progress has been made within recent years in interpreting the dynamic character of groundwater systems, many key issues remain to be addressed. In particular, several areas demand attention: the role of sedimentological information (heterogeneity) in groundwater and transport models, the scaling-up of observations from outcrop scale to larger scales and the integration of geological and geophysical information of different quality into the description of an aquifer structure. Still nowadays many of the heterogeneities cannot be recognized directly because of the limitation of measurement techniques. This is probably one of the reasons for the limited application of aquifer-sedimentology and geophysics in practical cases. In order to consolidate, expand, and make a larger number of people aware of the contribution of modern aquifer-sedimentology, including modelling and ultra-high resolution geophysical methods, several lines of intervention were identified: (1) a better collaboration of the different disciplines on site-specific applied problems; (2) development of new modelling techniques combining data of different quality; (3) development of optimizing tools (position and number of wells, additional geophysical methods, baysian techniques); (4) development of a `common language' among sedimentologists and hydrogeologists to overcome communication problems.

  18. Detangling the Interrelationships between Self- Regulation and Ill-Structured Problem Solving in Problem-Based Learning

    ERIC Educational Resources Information Center

    Ge, Xun; Law, Victor; Huang, Kun

    2016-01-01

    One of the goals for problem-based learning (PBL) is to promote self-regulation. Although self-regulation has been studied extensively, its interrelationships with ill-structured problem solving have been unclear. In order to clarify the interrelationships, this article proposes a conceptual framework illustrating the iterative processes among…

  19. Effects of a Problem-Based Structure of Physics Contents on Conceptual Learning and the Ability to Solve Problems

    ERIC Educational Resources Information Center

    Becerra-Labra, Carlos; Gras-Marti, Albert; Torregrosa, Joaquin Martinez

    2012-01-01

    A model of teaching/learning is proposed based on a "problem-based structure" of the contents of the course, in combination with a training in paper and pencil problem solving that emphasizes discussion and quantitative analysis, rather than formulae plug-in. The aim is to reverse the high failure and attrition rate among engineering…

  20. Detangling the Interrelationships between Self- Regulation and Ill-Structured Problem Solving in Problem-Based Learning

    ERIC Educational Resources Information Center

    Ge, Xun; Law, Victor; Huang, Kun

    2016-01-01

    One of the goals for problem-based learning (PBL) is to promote self-regulation. Although self-regulation has been studied extensively, its interrelationships with ill-structured problem solving have been unclear. In order to clarify the interrelationships, this article proposes a conceptual framework illustrating the iterative processes among…

  1. Using Digital Mapping Tool in Ill-Structured Problem Solving

    ERIC Educational Resources Information Center

    Bai, Hua

    2013-01-01

    Scaffolding students' problem solving and helping them to improve problem solving skills are critical in instructional design courses. This study investigated the effects of students' uses of a digital mapping tool on their problem solving performance in a design case study. It was found that the students who used the digital mapping tool…

  2. Outstanding problems in the band structures of 152Sm

    NASA Astrophysics Data System (ADS)

    Gupta, J. B.; Hamilton, J. H.

    2017-09-01

    The recent data on B (E 2 ) values, deduced from the multi-Coulex excitation of the low spin states in the decay of 152Sm, and other experimental findings in the last two decades are compared with the predictions from the microscopic dynamic pairing plus quadrupole model of Kumar and Baranger. The 1292.8 keV 2+ state is assigned to the 03 + band, and the K =2 assignment of the 1769 keV 2+ state is confirmed. The anomaly of the shape coexistence of the assumed spherical β band versus the deformed ground band is resolved. The values from the critical point symmetry X(5) support the collective character of the β band. The problem with the two-term interacting boson model Hamiltonian in predicting β and γ bands in 152Sm leads to interesting consequences. The collective features of the second excited Kπ=03 + band are preferred over the "pairing isomer" view. Also the multiphonon nature of the higher lying Kπ=22 +β γ band and Kπ=4+ band are illustrated vis-à-vis the new data and the nuclear structure theory.

  3. Problems in understanding the structure and assembly of viruses

    SciTech Connect

    King, J.

    1997-12-01

    Though viruses infect the cells of all groups of animals, plants, and microorganisms, their structures follow a limited number of general themes; spherical or cylindrical shells built of hundreds of repeated protein subunits enclosing a nucleic acid - DNA or RNA - genome. Since the 1960s it has been known that the protein shells of spherical viruses in fact conform to icosahedral symmetry or to subtle deviations from icosahedral symmetry. The construction of the shell lattices and the transformations they go through in the different stages of the viral life cycle are not fully understood. The shells contain the nucleic in a highly condensed state, of unknown coiling/organization. Features of the well studied bacterial viruses will be reviewed, with examples from adenoviruses, herpesviruses, poliovirus, and HIV. The emergence of new viral disease has led to increased interest in the development of agents which interfere with virus reproduction at the level of the assembly or function of the organized particle. Recently computational approaches to the problem of virus assembly have made important contributions to clarifying shell assembly processes. 1 ref.

  4. Problem of Auroral Oval Mapping and Multiscale Auroral Structures

    NASA Astrophysics Data System (ADS)

    Antonova, Elizaveta; Stepanova, Marina; Kirpichev, Igor; Vovchenko, Vadim; Vorobjev, Viachislav; Yagodkina, Oksana

    The problem of the auroral oval mapping to the equatorial plane is reanalyzed taking into account the latest results of the analysis of plasma pressure distribution at low altitudes and at the equatorial plane. Statistical pictures of pressure distribution at low latitudes are obtained using data of DMSP observations. We obtain the statistical pictures of pressure distribution at the equatorial plane using data of THEMIS mission. Results of THEMIS observations demonstrate the existence of plasma ring surrounding the Earth at geocentric distances from ~6 till ~12Re. Plasma pressure in the ring is near to isotropic and its averaged values are larger than 0.2 nPa. We take into account that isotropic plasma pressure is constant along the field line and that the existence of field-aligned potential drops in the region of the acceleration of auroral electrons leads to pressure decrease at low altitudes. We show that most part of quite time auroral oval does not map to the real plasma sheet. It maps to the surrounding the Earth plasma ring. We also show that transverse currents in the plasma ring are closed inside the magnetosphere forming the high latitude continuation of the ordinary ring current. The obtained results are used for the explanation of ring like form of the auroral oval. We also analyze the processes of the formation of multiscale auroral structures including thin auroral arcs and discuss the difficulties of the theories of alfvenic acceleration of auroral electrons.

  5. Perspectives on Sleep, Sleep Problems, and Their Treatment, in People with Serious Mental Illnesses: A Systematic Review.

    PubMed

    Faulkner, Sophie; Bee, Penny

    Sleep problems are common in people with serious mental illness, and impact negatively on functioning and wellbeing. To understand the development of sleep problems, their maintenance, and their treatment, an in depth understanding of patient perspectives is crucial. A systematic literature review was conducted using Medline, AMED, PsychInfo, Embase and CINAHL. Qualitative and quantitative studies were included if they explored or measured patient perspectives on sleep, sleep problems or sleep treatments in people with serious mental illness. Of the 2,067 hits, only 22 met review inclusion criteria, and high quality evidence was sparse. The limited findings suggested sleep was seen as highly interlinked with mental health. Evaluations of treatments varied, however perceived efficacy and personalisation of treatments were valued. Some evidence suggested patient priorities and conceptualisations regarding sleep may diverge from those of validated screening tools developed in general population and sleep medicine samples. More rigorous research is needed to support adaptation and development of interventions and outcome measures for use in specialist mental health settings. Qualitative studies exploring the experience of sleep disturbance in particular diagnostic groups and contexts are urgently required, as are patient perspectives on sleep interventions.

  6. Perspectives on Sleep, Sleep Problems, and Their Treatment, in People with Serious Mental Illnesses: A Systematic Review

    PubMed Central

    Bee, Penny

    2016-01-01

    Sleep problems are common in people with serious mental illness, and impact negatively on functioning and wellbeing. To understand the development of sleep problems, their maintenance, and their treatment, an in depth understanding of patient perspectives is crucial. A systematic literature review was conducted using Medline, AMED, PsychInfo, Embase and CINAHL. Qualitative and quantitative studies were included if they explored or measured patient perspectives on sleep, sleep problems or sleep treatments in people with serious mental illness. Of the 2,067 hits, only 22 met review inclusion criteria, and high quality evidence was sparse. The limited findings suggested sleep was seen as highly interlinked with mental health. Evaluations of treatments varied, however perceived efficacy and personalisation of treatments were valued. Some evidence suggested patient priorities and conceptualisations regarding sleep may diverge from those of validated screening tools developed in general population and sleep medicine samples. More rigorous research is needed to support adaptation and development of interventions and outcome measures for use in specialist mental health settings. Qualitative studies exploring the experience of sleep disturbance in particular diagnostic groups and contexts are urgently required, as are patient perspectives on sleep interventions. PMID:27657927

  7. An embodied perspective on expertise in solving the problem of making a geologic map

    NASA Astrophysics Data System (ADS)

    Callahan, Caitlin Norah

    The task of constructing a geologic map is a cognitively and physically demanding field-based problem. The map produced is understood to be an individual's two-dimensional interpretation or mental model of the three-dimensional underlying geology. A popular view within the geoscience community is that teaching students how to make a geologic map is valuable for preparing them to deal with disparate and incomplete data sets, for helping them develop problem-solving skills, and for acquiring expertise in geology. Few previous studies have focused specifically on expertise in geologic mapping. Drawing from literature related to expertise, to problem solving, and to mental models, two overarching research questions were identified: How do geologists of different levels of expertise constrain and solve an ill-structured problem such as making a geologic map? How do geologists address the uncertainties inherent to the processes and interpretations involved in solving a geologic mapping problem? These questions were answered using a methodology that captured the physical actions, expressed thoughts, and navigation paths of geologists as they made a geologic map. Eight geologists, from novice to expert, wore a head-mounted video camera with an attached microphone to record those actions and thoughts, creating "video logs" while in the field. The video logs were also time-stamped, which allowed the visual and audio data to be synchronized with the GPS data that tracked participants' movements in the field. Analysis of the video logs yielded evidence that all eight participants expressed thoughts that reflected the process of becoming mentally situated in the mapping task (e.g. relating between distance on a map and distance in three-dimensional space); the prominence of several of these early thoughts waned in the expressed thoughts later in the day. All participants collected several types of data while in the field; novices, however, did so more continuously throughout

  8. Semantic Annotation of Complex Text Structures in Problem Reports

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.; Throop, David R.; Fleming, Land D.

    2011-01-01

    Text analysis is important for effective information retrieval from databases where the critical information is embedded in text fields. Aerospace safety depends on effective retrieval of relevant and related problem reports for the purpose of trend analysis. The complex text syntax in problem descriptions has limited statistical text mining of problem reports. The presentation describes an intelligent tagging approach that applies syntactic and then semantic analysis to overcome this problem. The tags identify types of problems and equipment that are embedded in the text descriptions. The power of these tags is illustrated in a faceted searching and browsing interface for problem report trending that combines automatically generated tags with database code fields and temporal information.

  9. A Cognitive Architecture for Solving Ill-Structured Problems

    DTIC Science & Technology

    1997-08-01

    and the " lightbulb problem" requires using a laser to fuse a filament in a lightbulb without breaking the surrounding bulb. Each proposition consists...Calculus Representations of Radiation and Lightbulb Problems RADIATION PROBLEM (target) Start: (ray-source (obj.ray) ri) (tissue (obj.tissue) r2) (tumor...tumor) r2i) (not-destroyed (obj.tissue) r22) LIGHTBULB PROBLEM (source) Start: (laser (obj-laser) bl) (bulb (obj-bulb) b2) (filament (obj-filament) b3

  10. Assisting Workers Displaced by Structural Change. An International Perspective.

    ERIC Educational Resources Information Center

    Leigh, Duane E.

    This monograph takes the perspective that increased awareness of how active labor market programs operate in other nations can substantially improve the way in which the United States deals with worker displacement. Chapter 1 considers the costs of worker displacement and how government programs designed to reduce these costs are evaluated.…

  11. How scientific is the science in ethnopharmacology? Historical perspectives and epistemological problems.

    PubMed

    Gertsch, Jürg

    2009-03-18

    This commentary is based on a general concern regarding the low level of self-criticism (-evaluation) in the interpretation of molecular pharmacological data published in ethnopharmacology-related journals. Reports on potentially new lead structures or pharmacological effects of medicinal plant extracts are mushrooming. At the same time, nonsense in bioassays is an increasing phenomenon in herbal medicine research. Only because a dataset is reproducible does not imply that it is meaningful. Currently, there are thousands of claims of pharmacological effects of medicinal plants and natural products. It is argued that claims to knowledge in ethnopharmacology, as in the exact sciences, should be rationally criticized if they have empirical content as it is the case with biochemical and pharmacological analyses. Here the major problem is the misemployment of the concentration-effect paradigm and the overinterpretation of data obtained in vitro. Given the almost exponential increase of scientific papers published it may be the moment to adapt to a falsificationist methodology.

  12. Pre-Service Elementary Teachers' Motivation and Ill-Structured Problem Solving in Korea

    ERIC Educational Resources Information Center

    Kim, Min Kyeong; Cho, Mi Kyung

    2016-01-01

    This article examines the use and application of an ill-structured problem to pre-service elementary teachers in Korea in order to find implications of pre-service teacher education with regard to contextualized problem solving by analyzing experiences of ill-structured problem solving. Participants were divided into small groups depending on the…

  13. Mathematical Abstraction in the Solving of Ill-Structured Problems by Elementary School Students in Korea

    ERIC Educational Resources Information Center

    Hong, Jee Yun; Kim, Min Kyeong

    2016-01-01

    Ill-structured problems can be regarded as one of the measures that meet recent social needs emphasizing students' abilities to solve real-life problems. This study aimed to analyze the mathematical abstraction process in solving such problems, and to identify the mathematical abstraction level ([I] Recognition of mathematical structure through…

  14. Mathematical Abstraction in the Solving of Ill-Structured Problems by Elementary School Students in Korea

    ERIC Educational Resources Information Center

    Hong, Jee Yun; Kim, Min Kyeong

    2016-01-01

    Ill-structured problems can be regarded as one of the measures that meet recent social needs emphasizing students' abilities to solve real-life problems. This study aimed to analyze the mathematical abstraction process in solving such problems, and to identify the mathematical abstraction level ([I] Recognition of mathematical structure through…

  15. Incremental Validity and Informant Effect from a Multi-Method Perspective: Assessing Relations between Parental Acceptance and Children’s Behavioral Problems

    PubMed Central

    Izquierdo-Sotorrío, Eva; Holgado-Tello, Francisco P.; Carrasco, Miguel Á.

    2016-01-01

    This study examines the relationships between perceived parental acceptance and children’s behavioral problems (externalizing and internalizing) from a multi-informant perspective. Using mothers, fathers, and children as sources of information, we explore the informant effect and incremental validity. The sample was composed of 681 participants (227 children, 227 fathers, and 227 mothers). Children’s (40% boys) ages ranged from 9 to 17 years (M = 12.52, SD = 1.81). Parents and children completed both the Parental Acceptance Rejection/Control Questionnaire (PARQ/Control) and the check list of the Achenbach System of Empirically Based Assessment (ASEBA). Statistical analyses were based on the correlated uniqueness multitrait-multimethod matrix (model MTMM) by structural equations and different hierarchical regression analyses. Results showed a significant informant effect and a different incremental validity related to which combination of sources was considered. A multi-informant perspective rather than a single one increased the predictive value. Our results suggest that mother–father or child–father combinations seem to be the best way to optimize the multi-informant method in order to predict children’s behavioral problems based on perceived parental acceptance. PMID:27242582

  16. What Does (and Doesn't) Make Analogical Problem Solving Easy? A Complexity-Theoretic Perspective

    ERIC Educational Resources Information Center

    Wareham, Todd; Evans, Patricia; van Rooij, Iris

    2011-01-01

    Solving new problems can be made easier if one can build on experiences with other problems one has already successfully solved. The ability to exploit earlier problem-solving experiences in solving new problems seems to require several cognitive sub-abilities. Minimally, one needs to be able to retrieve relevant knowledge of earlier solved…

  17. What Does (and Doesn't) Make Analogical Problem Solving Easy? A Complexity-Theoretic Perspective

    ERIC Educational Resources Information Center

    Wareham, Todd; Evans, Patricia; van Rooij, Iris

    2011-01-01

    Solving new problems can be made easier if one can build on experiences with other problems one has already successfully solved. The ability to exploit earlier problem-solving experiences in solving new problems seems to require several cognitive sub-abilities. Minimally, one needs to be able to retrieve relevant knowledge of earlier solved…

  18. Historical perspective: The problem of the origin of life in the context of developments in biology

    NASA Astrophysics Data System (ADS)

    Kamminga, Harmke

    1988-03-01

    The structure of the history of scientific ideas on the origin of life, after Darwin's theory of evolution brought the problem into focus, is discussed. 19th-century theories in the mainstream of historical development already included some notion of chemical evolution. These theories were limited, however, by their reliance on a protoplasmic view of life, according to which the protoplasmic substance combines all vital properties. It was only when this holistic concept of protoplasm was abandoned that a clear distinction between different vital functions such as metabolism and replication was made. This led to two schools of thought in the origin of life field, one inspired by biochemistry and one by genetics. Oparin's theory, which was rooted in the metabolic traditions of biochemistry, provided a model which has had a lasting impact in methodological terms and which helped to transform the field from a largely theoretical one to an area of active research. Genetically based theories, on the other hand, had a delayed impact in this respect, because of long-lasting uncertainty regarding the structural basis of gene function.

  19. Solution to certain problems in the failure of composite structures

    NASA Astrophysics Data System (ADS)

    Goodsell, Johnathan

    The present work contains the solution of two problems in composite structures. In the first, an approximate elasticity solution for prediction of the displacement, stress and strain fields within the m-layer, symmetric and balanced angle-ply composite laminate of finite-width subjected anticlastic bending deformation is developed. The solution is shown to recover classical laminated plate theory predictions at interior regions of the laminate and thereby illustrates the boundary layer character of this interlaminar phenomenon. The results exhibit the anticipated response in congruence with the solutions for uniform axial extension and uniform temperature change, where divergence of the interlaminar shearing stress is seen to occur at the intersection of the free-edge and planes between lamina of +theta and -theta orientation. The analytical results show excellent agreement with the finite-element predictions for the same boundary-value problem and thereby provide an efficient and compact solution available for parametric studies of the influence of geometry and material properties. The solution is combined with previously developed solutions for uniform axial extension and uniform temperature change of the identical laminate and the combined solution is exercised to compare the relative magnitudes of free-edge phenomenon arising from the different loading conditions, to study very thick laminates and laminates where the laminate width is less than the laminate thickness. Significantly, it was demonstrated that the solution is valid for arbitrary stacking sequence and the solution was exercised to examine antisymmetric and non-symmetric laminates. Finally, the solution was exercised to determine the dimensions of the boundary layer for very large numbers of layers. It was found that the dimension of the boundary layer width in bending is approximately twice that in uniform axial extension and uniform temperature change. In the second, the intrinsic flaw concept is

  20. On the latent structure of problem gambling: a taxometric analysis.

    PubMed

    James, Richard J E; O'Malley, Claire; Tunney, Richard J

    2014-10-01

    To test whether problem gambling is a categorical or dimensional disorder on the basis of two problem gambling assessments. This distinction discriminates between two different conceptualizations of problem gambling: one that problem gambling is defined by its addictive properties, the other that it is a continuum of harm. Using The British Gambling Prevalence Survey 2010, a nationally representative sample of the United Kingdom conducted by the National Centre for Social Research, five different taxometric analyses were carried out on cases from two problem gambling screens: the Problem Gambling Severity Index (PGSI) and a measure derived from the DSM-IV Pathological Gambling criteria. Two further analyses were conducted on the total scores for these measures. There was strong evidence that both scales were measuring a categorical construct. Fit indices consistently supported a categorical interpretation [comparison curve fit index (CCFI) > 0.6]. The PGSI analysis indicated the presence of a taxon (CCFIs = 0.633, 0.756). The analysis conducted on the adapted DSM-IV criteria indicated stronger quantitative support for a taxon (CCFIs = 0.717, 0.811 and 0.756) but items probing a loss of control were inconsistent. The taxometric analyses of both scales support a categorical interpretation (CCFIs = 0.628, 0.567), but extreme caution should be used due to high nuisance covariance. Two problem gambling screens (the Problem Gambling Severity Index and a measure derived from the DSM-IV Pathological Gambling criteria) appear to measure a categorical construct that taps into a categorical, loss of control model of problem gambling. There is some evidence that the two screens measure different aspects of an addiction construct. © 2014 Society for the Study of Addiction.

  1. On Multilevel Model Reliability Estimation From the Perspective of Structural Equation Modeling

    ERIC Educational Resources Information Center

    Raykov, Tenko; Marcoulides, George A.

    2006-01-01

    A covariance structure modeling perspective on reliability estimation can be used to construct a formal approach to estimation of reliability in multilevel models. This article presents a didactic discussion of the relation between a structural modeling procedure for scale reliability estimation and the notion of reliability of observed means in…

  2. The structure of problem behaviours among Irish adolescents.

    PubMed

    Grube, J W; Morgan, M

    1990-05-01

    Problem behaviour theory proposes that adolescent substance use and other problem behaviours comprise a single dimension reflecting a general underlying tendency towards deviance. This general deviance hypothesis was tested with survey data obtained from 2731 adolescents from Dublin, Ireland. A series of hierarchical maximum likelihood factor analyses indicated that three specific factors were necessary to account for the covariation among problem behaviour measures. These factors corresponded to substance use (drinking, smoking, marijuana use, and other drug use), relatively minor problem behaviours (swearing, lying), and relatively serious problem behaviours (stealing, vandalism). Contrary to the general deviance hypothesis, a second order factor representing general deviance accounted for only 14% of the variance in substance use, on the average, as opposed to 74% of the variance in minor and serious problem behaviours. These findings thus indicate that substance use among these Irish adolescents is relatively independent of a general tendency toward deviance. They also suggest that the general deviance hypothesis, as it usually is applied, may be culturally specific and relevant only for adolescents from the United States and similar cultural contexts.

  3. Embellishing Problem-Solving Examples with Deep Structure Information Facilitates Transfer

    ERIC Educational Resources Information Center

    Lee, Hee Seung; Betts, Shawn; Anderson, John R.

    2017-01-01

    Appreciation of problem structure is critical to successful learning. Two experiments investigated effective ways of communicating problem structure in a computer-based learning environment and tested whether verbal instruction is necessary to specify solution steps, when deep structure is already embellished by instructional examples.…

  4. Embellishing Problem-Solving Examples with Deep Structure Information Facilitates Transfer

    ERIC Educational Resources Information Center

    Lee, Hee Seung; Betts, Shawn; Anderson, John R.

    2017-01-01

    Appreciation of problem structure is critical to successful learning. Two experiments investigated effective ways of communicating problem structure in a computer-based learning environment and tested whether verbal instruction is necessary to specify solution steps, when deep structure is already embellished by instructional examples.…

  5. The Space Physics ``Data Problem'' from the Perspectives of Different Stakeholders (Invited)

    NASA Astrophysics Data System (ADS)

    Donovan, E. F.

    2010-12-01

    Researchers, the PIs of VOs, and funding agencies frequently refer to an overarching “the data problem”. The Heliophysical Data Environment and other programs in the US and around the world have been put in place to address this issue. The data environment in space physics has evolved significantly in the last decade, and as a result there has been a dramatic and definitely positive increase in the effectiveness of systems for delivery of data to the research community. This has manifested itself in the form of in general much shorter (frequently less than a day) times between observation and the availability of scientific data products, greater uniformity in and long-term stability of file types and structures, the implementation of metadata standards, the establishment of remarkably effective summary plots and web-based browsing tools, and the growing availability of software that makes working with the scientific data products much easier than it used to be. Still, there are issues related to data and data services that need to be revisited as the data environment continues to evolve. Foremost in my mind is a sense that from the perspectives of funding agencies, producers of different types of data, and data users there is certainly not one “data problem”. For example, as a general rule funding agencies want data widely used, while university researchers who are producing data want to lead discovery-type research that uses that data in some key way. The PI of a big project usually benefits optimally if the data is totally open and widely utilized, while the interests of a grad student carrying out a project that centers in some way on data are often best served by a possibly years-long period during which access to that specific data is not open to the broader community. Novice or one-time users of a type of data are often best served by a web-based tool that will make a straightforward plot for them, while expert users usually just want access to a

  6. Activity problems in everyday life--patients' perspectives of hand osteoarthritis: "try imagining what it would be like having no hands".

    PubMed

    Bukhave, Elise Bromann; Huniche, Lotte

    2014-01-01

    To explore first-person perspectives on activities and participation in everyday life among people with hand osteoarthritis (OA). Semi-structured interviews were carried out with 5 men and 26 women of different ages living with hand OA. Supplemental data were collected via photo-interviews of two of the men and nine of the women. The analytical process was inspired by the interpretive phenomenological analysis and informed by the interpretive frameworks of critical psychology and social practice theory. Empirical findings indicate that persons with hand OA experience activity problems and participation limitations in the conduct of everyday life. Activity problems were related to self-care, paid work, as well as leisure activities. The participants also reported employing different strategies attempting to overcome the challenges of their everyday lives in order to keep actively performing valued activities. They reported environmental support of utmost importance for these attempts. Social participation in networks was also reported to be affected by the participants' activity problems. Arranging everyday life is complex and is carried out in structures of social practice. A supportive physical and social environment facilitates participation. The findings highlight the importance of paying attention to individual needs in rehabilitation processes.

  7. The Use of Video Cases in a Multimedia Learning Environment for Facilitating High School Students' Inquiry into a Problem from Varying Perspectives

    NASA Astrophysics Data System (ADS)

    Zydney, Janet Mannheimer; Grincewicz, Amy

    2011-12-01

    This study investigated the connection between the use of video cases within a multimedia learning environment and students' inquiry into a socio-scientific problem. The software program was designed based on principles from the Cognitive Flexibility Theory (CFT) and incorporated video cases of experts with differing perspectives. Seventy-nine 10th-grade students in an urban high school participated in this study. After watching the expert videos, students generated investigative questions and reflected on how their ideas changed over time. This study found a significant correlation between the time students spent watching the expert videos and their ability to consider the problem's perspectives as well as their ability to integrate these perspectives within their questions. Moreover, problem-solving ability and time watching the videos were detected as possible influential predictors of students' consideration of the problem's perspectives within their questions. Although students watched all video cases in equivalent ways, one of the video cases, which incorporated multiple perspectives as opposed to just presenting one perspective, appeared most influential in helping students integrate the various perspectives into their own thinking. A qualitative analysis of students' reflections indicated that many students appreciated the complexity, authenticity, and ethical dimensions of the problem. It also revealed that while the majority of students thought critically about the problem, some students still had naïve or simplistic ways of thinking. This study provided some preliminary evidence that offering students the opportunity to watch videos of different perspectives may influence them to think in alternative ways about a complex problem.

  8. Using a Brief Form of Problem-Based Learning in a Research Methods Class: Perspectives of Instructor and Students

    ERIC Educational Resources Information Center

    Elder, Anastasia D.

    2015-01-01

    Problem based learning (PBL) is an instructional method aimed at engaging students in collaboratively solving an ill-structured problem. PBL has been presented and researched as an overhaul of existing curriculum design, yet a modified version may be attractive to college instructors who desire active learning on the part of their students, but…

  9. Integrated Force Method Solution to Indeterminate Structural Mechanics Problems

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.; Hopkins, Dale A.; Halford, Gary R.

    2004-01-01

    Strength of materials problems have been classified into determinate and indeterminate problems. Determinate analysis primarily based on the equilibrium concept is well understood. Solutions of indeterminate problems required additional compatibility conditions, and its comprehension was not exclusive. A solution to indeterminate problem is generated by manipulating the equilibrium concept, either by rewriting in the displacement variables or through the cutting and closing gap technique of the redundant force method. Compatibility improvisation has made analysis cumbersome. The authors have researched and understood the compatibility theory. Solutions can be generated with equal emphasis on the equilibrium and compatibility concepts. This technique is called the Integrated Force Method (IFM). Forces are the primary unknowns of IFM. Displacements are back-calculated from forces. IFM equations are manipulated to obtain the Dual Integrated Force Method (IFMD). Displacement is the primary variable of IFMD and force is back-calculated. The subject is introduced through response variables: force, deformation, displacement; and underlying concepts: equilibrium equation, force deformation relation, deformation displacement relation, and compatibility condition. Mechanical load, temperature variation, and support settling are equally emphasized. The basic theory is discussed. A set of examples illustrate the new concepts. IFM and IFMD based finite element methods are introduced for simple problems.

  10. When Your "Problem" Becomes Mine: Adult Female Siblings' Perspectives of Having a Brother with a Disability

    ERIC Educational Resources Information Center

    Pompeo, Michelle N.

    2009-01-01

    This study is a retrospective look at adult female siblings' perspectives of their childhoods and present identities based on having a brother with a disability. This paper focuses on siblings' experiences within educational and public domains, and how such experiences have shaped their personalities and career choices. Qualitative findings were…

  11. Educational Leadership in the Philippines: Principals' Perspectives on Problems and Possibilities for Change

    ERIC Educational Resources Information Center

    Brooks, Jeffrey S.; Sutherland, Ian E.

    2014-01-01

    This case study of school leaders in the Southern Philippines explored principal perspectives on local dynamics that facilitate and impede meaningful educational change. The research indicated that change is a complicated proposition in the region, and that some principals are better or worse equipped to lead depending on a variety of cultural,…

  12. The Problem of Data in the Cognitive Linguistic Research on Metonymy: A Cross-Linguistic Perspective

    ERIC Educational Resources Information Center

    Brdar-Szabo, Rita; Brdar, Mario

    2012-01-01

    The general goal of the present paper is to demonstrate how cross-linguistic (contrastive) data can broaden the perspective in cognitive linguistic research on metonymy, which may raise a host of questions calling for a revision of some widely accepted views. A more specific, methodological goal is to show how the introspection-driven research and…

  13. Challenges Experienced by Korean Medical Students and Tutors during Problem-Based Learning: A Cultural Perspective

    ERIC Educational Resources Information Center

    Ju, Hyunjung; Choi, Ikseon; Rhee, Byoung Doo; Tae-Lee, Jong

    2016-01-01

    How people learn is influenced by the cultural contexts in which their learning occurs. This qualitative case study explored challenges Korean medical students and tutors experienced during their PBL sessions from a cultural perspective using Hofstede's cultural dimensions. Twelve preclinical medical students and nine tutors from a large Korean…

  14. The Problem of the Pyramid or Egyptian Mathematics from a Postmodern Perspective

    ERIC Educational Resources Information Center

    Shutler, Paul M. E.

    2009-01-01

    We consider Egyptian mathematics from a postmodern perspective, by which we mean suspending judgement as to strict correctness in order to appreciate the genuine mathematical insights which they did have in the context in which they were working. In particular we show that the skill which the Egyptians possessed of obtaining the general case from…

  15. The Problem of Data in the Cognitive Linguistic Research on Metonymy: A Cross-Linguistic Perspective

    ERIC Educational Resources Information Center

    Brdar-Szabo, Rita; Brdar, Mario

    2012-01-01

    The general goal of the present paper is to demonstrate how cross-linguistic (contrastive) data can broaden the perspective in cognitive linguistic research on metonymy, which may raise a host of questions calling for a revision of some widely accepted views. A more specific, methodological goal is to show how the introspection-driven research and…

  16. Challenges Experienced by Korean Medical Students and Tutors during Problem-Based Learning: A Cultural Perspective

    ERIC Educational Resources Information Center

    Ju, Hyunjung; Choi, Ikseon; Rhee, Byoung Doo; Tae-Lee, Jong

    2016-01-01

    How people learn is influenced by the cultural contexts in which their learning occurs. This qualitative case study explored challenges Korean medical students and tutors experienced during their PBL sessions from a cultural perspective using Hofstede's cultural dimensions. Twelve preclinical medical students and nine tutors from a large Korean…

  17. "The Problem of Trinity College Dublin": A Historical Perspective on Rationalisation in Higher Education in Ireland

    ERIC Educational Resources Information Center

    Walsh, John

    2014-01-01

    This paper offers a historical perspective on government policies for the rationalisation of higher education (HE) in Ireland through a critical re-appraisal of the initiative for "merger" of Trinity College and University College Dublin. The initiative launched by Donogh O'Malley in 1967 was the first significant attempt by an Irish…

  18. "The Problem of Trinity College Dublin": A Historical Perspective on Rationalisation in Higher Education in Ireland

    ERIC Educational Resources Information Center

    Walsh, John

    2014-01-01

    This paper offers a historical perspective on government policies for the rationalisation of higher education (HE) in Ireland through a critical re-appraisal of the initiative for "merger" of Trinity College and University College Dublin. The initiative launched by Donogh O'Malley in 1967 was the first significant attempt by an Irish…

  19. Shyness and Social Phobia: A Social Work Perspective on a Problem in Living.

    ERIC Educational Resources Information Center

    Walsh, Joseph

    2002-01-01

    Social phobia can be conceptualized from a social work perspective as an extreme shyness that can be overcome with cognitive learning and behavioral rehearsal. This article reviews the biopsychosocial causes of social phobia and presents a summary of cognitive and behavioral interventions with empirically demonstrated effectiveness. (Author)

  20. Parent and Teacher Perspectives about Problem Behavior in Children with Williams Syndrome

    ERIC Educational Resources Information Center

    Klein-Tasman, Bonita P.; Lira, Ernesto N.; Li-Barber, Kirsten T.; Gallo, Frank J.; Brei, Natalie G.

    2015-01-01

    Problem behavior of 52 children with Williams syndrome ages 6 to 17 years old was examined based on both parent and teacher report. Generally good inter-rater agreement was found. Common areas of problem behavior based both on parent and teacher report included attention problems, anxiety difficulties, repetitive behaviors (e.g., obsessions,…

  1. Parent and Teacher Perspectives about Problem Behavior in Children with Williams Syndrome

    ERIC Educational Resources Information Center

    Klein-Tasman, Bonita P.; Lira, Ernesto N.; Li-Barber, Kirsten T.; Gallo, Frank J.; Brei, Natalie G.

    2015-01-01

    Problem behavior of 52 children with Williams syndrome ages 6 to 17 years old was examined based on both parent and teacher report. Generally good inter-rater agreement was found. Common areas of problem behavior based both on parent and teacher report included attention problems, anxiety difficulties, repetitive behaviors (e.g., obsessions,…

  2. 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…

  3. The Factor Structure of the Problem-Solving Inventory: Measuring Perceptions of Personal Problem Solving.

    ERIC Educational Resources Information Center

    Baker, Stanley B.; Roberts, Dennis M.

    1989-01-01

    Administered Problem-Solving Inventory (PSI) to ninth graders (N=198) to examine whether results would be similar to those obtained with collegiate population on which PSI was normed. Results revealed three factors which were defined somewhat differently with this younger population. (NB)

  4. A study of problems encountered in Granger causality analysis from a neuroscience perspective.

    PubMed

    Stokes, Patrick A; Purdon, Patrick L

    2017-08-22

    Granger causality methods were developed to analyze the flow of information between time series. These methods have become more widely applied in neuroscience. Frequency-domain causality measures, such as those of Geweke, as well as multivariate methods, have particular appeal in neuroscience due to the prevalence of oscillatory phenomena and highly multivariate experimental recordings. Despite its widespread application in many fields, there are ongoing concerns regarding the applicability of Granger causality methods in neuroscience. When are these methods appropriate? How reliably do they recover the system structure underlying the observed data? What do frequency-domain causality measures tell us about the functional properties of oscillatory neural systems? In this paper, we analyze fundamental properties of Granger-Geweke (GG) causality, both computational and conceptual. Specifically, we show that (i) GG causality estimates can be either severely biased or of high variance, both leading to spurious results; (ii) even if estimated correctly, GG causality estimates alone are not interpretable without examining the component behaviors of the system model; and (iii) GG causality ignores critical components of a system's dynamics. Based on this analysis, we find that the notion of causality quantified is incompatible with the objectives of many neuroscience investigations, leading to highly counterintuitive and potentially misleading results. Through the analysis of these problems, we provide important conceptual clarification of GG causality, with implications for other related causality approaches and for the role of causality analyses in neuroscience as a whole.

  5. A study of problems encountered in Granger causality analysis from a neuroscience perspective

    PubMed Central

    Stokes, Patrick A.; Purdon, Patrick L.

    2017-01-01

    Granger causality methods were developed to analyze the flow of information between time series. These methods have become more widely applied in neuroscience. Frequency-domain causality measures, such as those of Geweke, as well as multivariate methods, have particular appeal in neuroscience due to the prevalence of oscillatory phenomena and highly multivariate experimental recordings. Despite its widespread application in many fields, there are ongoing concerns regarding the applicability of Granger causality methods in neuroscience. When are these methods appropriate? How reliably do they recover the system structure underlying the observed data? What do frequency-domain causality measures tell us about the functional properties of oscillatory neural systems? In this paper, we analyze fundamental properties of Granger–Geweke (GG) causality, both computational and conceptual. Specifically, we show that (i) GG causality estimates can be either severely biased or of high variance, both leading to spurious results; (ii) even if estimated correctly, GG causality estimates alone are not interpretable without examining the component behaviors of the system model; and (iii) GG causality ignores critical components of a system’s dynamics. Based on this analysis, we find that the notion of causality quantified is incompatible with the objectives of many neuroscience investigations, leading to highly counterintuitive and potentially misleading results. Through the analysis of these problems, we provide important conceptual clarification of GG causality, with implications for other related causality approaches and for the role of causality analyses in neuroscience as a whole. PMID:28778996

  6. Elimination of Leprosy as a public health problem by 2000 AD: an epidemiological perspective

    PubMed Central

    Nsagha, Dickson Shey; Bamgboye, Elijah Afolabi; Assob, Jules Clement Nguedia; Njunda, Anna Longdoh; Kamga, Henri Lucien Foumou; Zoung-Kanyi Bissek, Anne-Cécile; Tabah, Earnest Nji; Oyediran, Alain Bankole OO; Njamnshi, Alfred Kongnyu

    2011-01-01

    Introduction Leprosy is caused by Mycobacterium leprae and manifests as damage to the skin and peripheral nerves. The disease is dreaded because it causes deformities, blindness and disfigurement. Worldwide, 2 million people are estimated to be disabled by leprosy. Multidrug therapy is highly effective in curing leprosy, but treating the nerve damage is much more difficult. The World Health Assembly targeted to eliminate leprosy as a public health problem from the world by 2000. The objective of the review was to assess the successes of the leprosy elimination strategy, elimination hurdles and the way forward for leprosy eradication. Methods A structured search was used to identify publications on the elimination strategy. The keywords used were leprosy, elimination and 2000. To identify potential publications, we included papers on leprosy elimination monitoring, special action projects for the elimination of leprosy, modified leprosy elimination campaigns, and the Global Alliance to eliminate leprosy from the following principal data bases: Cochrane data base of systematic reviews, PubMed, Medline, EMBASE, and the Leprosy data base. We also scanned reference lists for important citations. Key leprosy journals including WHO publications were also reviewed. Results The search identified 63 journal publications on leprosy-related terms that included a form of elimination of which 19 comprehensively tackled the keywords including a book on leprosy elimination. In 1991, the 44th World Health Assembly called for the elimination of leprosy as a public health problem in the world by 2000. Elimination was defined as less than one case of leprosy per 10000-population. Elimination has been made possible by a confluence of several orders of opportunities: the scientific (the natural history of leprosy at the present state of knowledge), technological (multi-drug therapy and the blister pack); political (commitment of governments) and financial (support from NGOs for example

  7. Elimination of leprosy as a public health problem by 2000 AD: an epidemiological perspective.

    PubMed

    Nsagha, Dickson Shey; Bamgboye, Elijah Afolabi; Assob, Jules Clement Nguedia; Njunda, Anna Longdoh; Kamga, Henri Lucien Foumou; Zoung-Kanyi Bissek, Anne-Cécile; Tabah, Earnest Nji; Oyediran, Alain Bankole O O; Njamnshi, Alfred Kongnyu

    2011-01-01

    Leprosy is caused by Mycobacterium leprae and manifests as damage to the skin and peripheral nerves. The disease is dreaded because it causes deformities, blindness and disfigurement. Worldwide, 2 million people are estimated to be disabled by leprosy. Multidrug therapy is highly effective in curing leprosy, but treating the nerve damage is much more difficult. The World Health Assembly targeted to eliminate leprosy as a public health problem from the world by 2000. The objective of the review was to assess the successes of the leprosy elimination strategy, elimination hurdles and the way forward for leprosy eradication. A structured search was used to identify publications on the elimination strategy. The keywords used were leprosy, elimination and 2000. To identify potential publications, we included papers on leprosy elimination monitoring, special action projects for the elimination of leprosy, modified leprosy elimination campaigns, and the Global Alliance to eliminate leprosy from the following principal data bases: Cochrane data base of systematic reviews, PubMed, Medline, EMBASE, and the Leprosy data base. We also scanned reference lists for important citations. Key leprosy journals including WHO publications were also reviewed. The search identified 63 journal publications on leprosy-related terms that included a form of elimination of which 19 comprehensively tackled the keywords including a book on leprosy elimination. In 1991, the 44th World Health Assembly called for the elimination of leprosy as a public health problem in the world by 2000. Elimination was defined as less than one case of leprosy per 10000-population. Elimination has been made possible by a confluence of several orders of opportunities: the scientific (the natural history of leprosy at the present state of knowledge), technological (multi-drug therapy and the blister pack); political (commitment of governments) and financial (support from NGOs for example the Nippon Foundation that

  8. Structuring Video Cases to Support Future Teachers' Problem Solving

    ERIC Educational Resources Information Center

    Kale, Ugur; Whitehouse, Pamela

    2012-01-01

    This study examined preservice teachers' problem-solving skills through the use of an online video case study. Eighty preservice teachers participated in the study with a three-level video presentation by a two-grade-level between-subjects factorial design. The study incorporates a content analysis framework to examine both the components and the…

  9. Provide Structure for Children With Learning and Behavior Problems

    ERIC Educational Resources Information Center

    Swanson, Terri Cooper

    2005-01-01

    Children with learning and behavior problems often have difficulty getting through their day, to a great extent because they have difficulty organizing themselves and understanding the organization of the environment around them. Neurotypical children and adults organize themselves in many ways by using calendars, planners, lists, and so forth.…

  10. Exploiting Explicit and Implicit Structure in Complex Optimization Problems

    DTIC Science & Technology

    2014-09-24

    Applications 161(1) (2014) 179-198. [4] J.P. Luna , C. Sagastizábal and M. Solodov, A class of Dantzig--Wolfe type decomposition methods for variational...inequality problems, Mathematical Programming 143 (2014) 177-209. [5] J.P. Luna , C. Sagastizábal and M. Solodov, Complementarity and

  11. "We want the world and we want it now": Materialism, time perspectives and problem spending tendency of Chinese.

    PubMed

    Ku, Lisbeth; Wu, Anise M S; Lao, Angie K P; Lam, Kerwin I N

    2016-10-06

    Chinese consumers' spending has been expanding rapidly in the past decade, and along with it household and credit card debt. The present research collected evidence to triangulate the contention that materialism is positively related with Chinese's problem spending tendency (PST), and that present-time-perspective (PTP) and future-time perspectives (FTP) interact systematically with materialism to affect PST. A survey of the general population in Macao, China (Study 1; N = 239) confirmed that materialism was positively correlated with PST. An interaction between materialism and PTP intensified the relationship, whereas an interaction with FTP weakened the relationship. Another survey with a sample of university students (Study 2; N = 223) again found positive relationships among PST, materialism, and PTP, as measured by temporal discount rate. But further exploration showed that PST was only related with temporal discounting among high materialists, but not among low materialists. Study 3 experimentally examined the causal effects of materialism and FTP on PST. When being primed of an orientation towards materialism (n = 33), the participants' planned consumption doubled that of the control group (n = 31). A FTP prime interacted with materialism prime and put a "damper" on participants' planned spending (n = 29), compared to their counterparts who were not primed of such a time perspective.

  12. The Structure of the Help-Seeking Process in Collaboratively Using a Computer Coach in Problem-Based Learning

    ERIC Educational Resources Information Center

    Mercier, Julien; Frederiksen, Carl

    2008-01-01

    Research on help seeking with a computer coach providing on-demand help has not produced fully adequate models of the process from a cognitive perspective. The present study postulates a model of help seeking from a cognitive perspective and tests this model in a learning situation characterized as problem-based and computer-supported. The…

  13. A perspective on technical needs in computational structures technology

    NASA Technical Reports Server (NTRS)

    Abdi, Frank F.; Savoni, Gregory L.; Newell, Kenneth J.

    1992-01-01

    The wide spectrum of needs and applications are demonstrated of computational structural mechanics. The spectrum ranges from micro structural mechanics to the optimization of the performance of aerovehicles. Critical high leveraged technologies will require engineering process modernization and automation, affordable structures and materials, and advanced computational technology. Recent advances at Rockwell International in computational structural mechanics addressed these issues and improve the ability to achieve advanced aircraft objectives.

  14. A perspective on technical needs in computational structures technology

    NASA Astrophysics Data System (ADS)

    Abdi, Frank F.; Savoni, Gregory L.; Newell, Kenneth J.

    1992-05-01

    The wide spectrum of needs and applications are demonstrated of computational structural mechanics. The spectrum ranges from micro structural mechanics to the optimization of the performance of aerovehicles. Critical high leveraged technologies will require engineering process modernization and automation, affordable structures and materials, and advanced computational technology. Recent advances at Rockwell International in computational structural mechanics addressed these issues and improve the ability to achieve advanced aircraft objectives.

  15. Optimal structural design via optimality criteria as a nonsmooth mechanics problem

    NASA Astrophysics Data System (ADS)

    Tzaferopoulos, M. Ap.; Stravroulakis, G. E.

    1995-06-01

    In the theory of plastic structural design via optimality criteria (due to W. Prager), the optimal design problem is transformed to a nonlinear elastic structural analysis problem with appropriate stress-strain laws, which generally include complete vertical branches. In this context, the concept of structural universe (in the sense of G. Rozvany) permits the treatment of complicated optimal layout problems. Recent progress in the field of nonsmooth mechanics makes the solution of structural analysis problems with this kind of 'complete' law possible. Elements from the two fields are combined in this paper for the solution of optimal design and layout problems for structures. The optimal layout of plane trusses with various specific cost functions is studied here as a representative problem. The use of convex, continuous and piecewise linear specific cost functions for the structural members leads to problems of linear variational inequalities or equivalently piecewise linear, convex but nonsmooth optimization problems, which are solved by means of an iterative algorithm based on sequential linear programming techniques. Numerical examples illustrate the theory and its applicability to practical engineering structures. Following a parametric investigation of an optimal bridge design, certain aspects of the optimal truss layout problem are discussed, which can be extended to other types of structural systems as well.

  16. Reference Map Technique for Incompressible Fluid-Structure Interaction Problems

    NASA Astrophysics Data System (ADS)

    Rycroft, Chris; Wu, Chen-Hung; Yu, Yue; Kamrin, Ken

    2016-11-01

    We present a fully Eulerian approach to simulate soft structures immersed in an incompressible fluid. The flow is simulated on a fixed grid using a second order projection method to solve the incompressible Navier-Stokes equations, and the fluid-structure interfaces are modeled using the level set method. By introducing a reference map variable to model finite-deformation constitutive relations in the structure on the same grid as the fluid, the interfacial coupling is highly simplified. This fully Eulerian approach provides a computationally efficient alternative to moving mesh approaches. Example simulations featuring many-body contacts and flexible swimmers will be presented.

  17. A dose-response perspective on college drinking and related problems.

    PubMed

    Gruenewald, Paul J; Johnson, Fred W; Ponicki, William R; Lascala, Elizabeth A

    2010-02-01

    In order to examine the degree to which heavy drinking contributes to risks for problems among college drinkers this paper develops and tests a dose-response model of alcohol use that relates frequencies of drinking specific quantities of alcohol to the incidence of drinking problems. A mathematical model was developed that enabled estimation of dose-response relationships between drinking quantities and drinking problems using self-report data from 8698 college drinkers across 14 campuses in California, USA. The model assumes that drinking risks are a direct monotone function of the amount consumed per day and additive across drinking days. Drinking problems accumulate across drinking occasions and are the basis for cumulative reports of drinking problems reported by college drinkers. Statistical analyses using the model showed that drinking problems were related to every drinking level, but increased fivefold at three drinks and more gradually thereafter. Problems were associated most strongly with occasions on which three drinks were consumed, and more than half of all reported problems were related to occasions on which four or fewer drinks were consumed. There were some important differences in dose-responsiveness between men and women and between different groups of 'light', 'moderate' and 'heavier' drinkers. Many problems among college students are associated with drinking relatively small amounts of alcohol (two to four drinks). Programs to reduce college drinking problems should emphasize risks associated with low drinking levels.

  18. Hybrid schemes based on quantum mechanics/molecular mechanics simulations goals to success, problems, and perspectives.

    PubMed

    Ferrer, Silvia; Ruiz-Pernía, Javier; Martí, Sergio; Moliner, Vicent; Tuñón, Iñaki; Bertrán, Juan; Andrés, Juan

    2011-01-01

    The development of characterization techniques, advanced synthesis methods, as well as molecular modeling has transformed the study of systems in a well-established research field. The current research challenges in biocatalysis and biotransformation evolve around enzyme discovery, design, and optimization. How can we find or create enzymes that catalyze important synthetic reactions, even reactions that may not exist in nature? What is the source of enzyme catalytic power? To answer these and other related questions, the standard strategies have evolved from trial-and-error methodologies based on chemical knowledge, accumulated experience, and common sense into a clearly multidisciplinary science that allows one to reach the molecular design of tailor-made enzyme catalysts. This is even more so when one refers to enzyme catalysts, for which the detailed structure and composition are known and can be manipulated to introduce well-defined residues which can be implicated in the chemical rearrangements taking place in the active site. The methods and techniques of theoretical and computational chemistry are becoming more and more important in both understanding the fundamental biological roles of enzymes and facilitating their utilization in biotechnology. Improvement of the catalytic function of enzymes is important from scientific and industrial viewpoints, and to put this fact in the actual perspective as well as the potentialities, we recommend the very recent report of Sanderson [Sanderson, K. (2011). Chemistry: enzyme expertise. Nature 471, 397.]. Great fundamental advances have been made toward the ab initio design of enzyme catalysts based on molecular modeling. This has been based on the molecular mechanistic knowledge of the reactions to be catalyzed, together with the development of advanced synthesis and characterization techniques. The corresponding molecular mechanism can be studied by means of powerful quantum chemical calculations. The catalytic

  19. Sampling problems: The small scale structure of precipitation

    NASA Technical Reports Server (NTRS)

    Crane, R. K.

    1981-01-01

    The quantitative measurement of precipitation characteristics for any area on the surface of the Earth is not an easy task. Precipitation is rather variable in both space and time, and the distribution of surface rainfall data given location typically is substantially skewed. There are a number of precipitation process at work in the atmosphere, and few of them are well understood. The formal theory on sampling and estimating precipitation appears considerably deficient. Little systematic attention is given to nonsampling errors that always arise in utilizing any measurement system. Although the precipitation measurement problem is an old one, it continues to be one that is in need of systematic and careful attention. A brief history of the presently competing measurement technologies should aid us in understanding the problem inherent in this measurement task.

  20. Perspectives.

    ERIC Educational Resources Information Center

    Robertson, Shari; Camerini, Michael

    2001-01-01

    Provides background information on the U.S. Immigration and Naturalization Service Asylum office. Uses the perspective of two movie producers as they filmed a documentary film, "Well-founded Fear", about asylum and refugee protection. Includes information on how to order a classroom aid and the film. (CMK)

  1. Perspectives

    ERIC Educational Resources Information Center

    Tarone, Elaine

    2013-01-01

    The topic of this "Perspectives" column is "Requiring a Proficiency Level as a Requirement for U.S. K-12 Teacher Licensure." In 1998, the American Council of Teachers of Foreign Languages (ACTFL) began to work with the National Council for Accreditation of Teacher Education (NCATE), which accredits teacher education programs…

  2. Perspectives

    ERIC Educational Resources Information Center

    Tarone, Elaine

    2013-01-01

    The topic of this "Perspectives" column is "Requiring a Proficiency Level as a Requirement for U.S. K-12 Teacher Licensure." In 1998, the American Council of Teachers of Foreign Languages (ACTFL) began to work with the National Council for Accreditation of Teacher Education (NCATE), which accredits teacher education programs…

  3. No-Regret Algorithms for Structured Prediction Problems

    DTIC Science & Technology

    2005-12-21

    perhaps the best known recent related papers are those of Kalai and Vempala [4] and Zinkevich [5]. The online convex program- ming problem has a much...contributions include: our bounds are better than those of previous algo- rithms such as that of Kalai and Vempala, since (unless p = 1 in Theorem 3) we do not...1956. [4] Adam Kalai and Santosh Vempala. Geometric algorithms for online optimization. Technical Report MIT-LCS-TR-861, MIT, 2002. [5] Martin

  4. Mapping brain structure and function: cellular resolution, global perspective.

    PubMed

    Zupanc, Günther K H

    2017-04-01

    A comprehensive understanding of the brain requires analysis, although from a global perspective, with cellular, and even subcellular, resolution. An important step towards this goal involves the establishment of three-dimensional high-resolution brain maps, incorporating brain-wide information about the cells and their connections, as well as the chemical architecture. The progress made in such anatomical brain mapping in recent years has been paralleled by the development of physiological techniques that enable investigators to generate global neural activity maps, also with cellular resolution, while simultaneously recording the organism's behavioral activity. Combination of the high-resolution anatomical and physiological maps, followed by theoretical systems analysis of the deduced network, will offer unprecedented opportunities for a better understanding of how the brain, as a whole, processes sensory information and generates behavior.

  5. 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…

  6. Using Jigsaw-Style Spectroscopy Problem-Solving to Elucidate Molecular Structure through Online Cooperative Learning

    ERIC Educational Resources Information Center

    Winschel, Grace A.; Everett, Renata K.; Coppola, Brian P.; Shultz, Ginger V.

    2015-01-01

    Cooperative learning was employed as an instructional approach to facilitate student development of spectroscopy problem solving skills. An interactive online environment was used as a framework to structure weekly discussions around spectroscopy problems outside of class. Weekly discussions consisted of modified jigsaw-style problem solving…

  7. Using Jigsaw-Style Spectroscopy Problem-Solving to Elucidate Molecular Structure through Online Cooperative Learning

    ERIC Educational Resources Information Center

    Winschel, Grace A.; Everett, Renata K.; Coppola, Brian P.; Shultz, Ginger V.

    2015-01-01

    Cooperative learning was employed as an instructional approach to facilitate student development of spectroscopy problem solving skills. An interactive online environment was used as a framework to structure weekly discussions around spectroscopy problems outside of class. Weekly discussions consisted of modified jigsaw-style problem solving…

  8. Problem-Solving Instruction and Students' Acquisition, Retention and Structuring of Economics Knowledge.

    ERIC Educational Resources Information Center

    Son, Byungro; VanSickle, Ronald L.

    The effectiveness of problem-solving instruction in promoting high school students' acquisition, retention, and structuring of economics knowledge was studied through six economics classes. The problem-solving instruction model was developed based on problem-based learning in medical education, following similar work by H. S. Barrows and R. M.…

  9. Transfer from Structured to Open-Ended Problem Solving in a Computerized Metacognitive Environment

    ERIC Educational Resources Information Center

    Kapa, Esther

    2007-01-01

    A new computerized environment introducing a variety of metacognitive support mechanisms (MSMs) in different phases of the problem-solving process was designed to influence students' transfer from solving structured problems (near transfer) to solving open-ended problems (far transfer). Two hundred and thirty one students (aged 13-14 years) were…

  10. Perspective: Role of structure prediction in materials discovery and design

    NASA Astrophysics Data System (ADS)

    Needs, Richard J.; Pickard, Chris J.

    2016-05-01

    Materials informatics owes much to bioinformatics and the Materials Genome Initiative has been inspired by the Human Genome Project. But there is more to bioinformatics than genomes, and the same is true for materials informatics. Here we describe the rapidly expanding role of searching for structures of materials using first-principles electronic-structure methods. Structure searching has played an important part in unraveling structures of dense hydrogen and in identifying the record-high-temperature superconducting component in hydrogen sulfide at high pressures. We suggest that first-principles structure searching has already demonstrated its ability to determine structures of a wide range of materials and that it will play a central and increasing part in materials discovery and design.

  11. Prediction of protein structure: the problem of fold multiplicity.

    PubMed

    Lomize, A L; Pogozheva, I D; Mosberg, H I

    1999-01-01

    Three-dimensional (3D) models of four CASP3 targets were calculated using a simple modeling procedure that includes prediction of regular secondary structure, analysis of possible beta-sheet topologies, assembly of amphiphilic helices and beta-sheets to bury their nonpolar surfaces, and adjustment of side-chain conformers and loops to provide close packing and saturation of the "hydrogen bond potential" (exposure of all polar groups to water or their involvement in intramolecular hydrogen bonds). It has been found that this approach allows construction of 3D models that, in some cases, properly reproduce the structural class of the protein (such as beta-barrel or beta-sandwich of definite shape and size) and details of tertiary structure (such as pairing of beta-strands), although all four models were more or less incorrect. Remarkably, some models had fewer water-exposed nonpolar side-chains, more hydrogen bonds, and smaller holes than the corresponding native structures (although the models had a larger water-accessible nonpolar surface). The results obtained indicate that hydrophobicity patterns do not unequivocally determine protein folds, and that any ab initio or fold recognition methods that operate with imprecise potential energy functions, or use crude geometrical approximations of the peptide chain, will probably produce many different nonnative structures.

  12. Solving Ill-Structured Problems in Asynchronous Online Discussions: Built-in Scaffolds vs. No Scaffolds

    ERIC Educational Resources Information Center

    Ng, Connie Siew Ling; Cheung, Wing Sum; Hew, Khe Foon

    2010-01-01

    Solving ill-structured problems is regarded as an important learning outcome in education as it allows learners to apply theories learnt into real practice. An asynchronous online discussion, with extended time for reflection, is an appropriate learning environment to engage learners in solving ill-structured problems. However, scaffolds may be…

  13. Solving Ill-Structured Problems in Asynchronous Online Discussions: Built-in Scaffolds vs. No Scaffolds

    ERIC Educational Resources Information Center

    Ng, Connie Siew Ling; Cheung, Wing Sum; Hew, Khe Foon

    2010-01-01

    Solving ill-structured problems is regarded as an important learning outcome in education as it allows learners to apply theories learnt into real practice. An asynchronous online discussion, with extended time for reflection, is an appropriate learning environment to engage learners in solving ill-structured problems. However, scaffolds may be…

  14. Adolescents', Mothers', and Fathers' Perspectives of Emotional and Behavioral Problems: Distress, Control, and Motivation to Change

    ERIC Educational Resources Information Center

    Duhig, Amy M.; Phares, Vicky

    2003-01-01

    Utilizing a clinical sample, this study examined relations between adolescents' subjective distress over their emotional/behavioral problems, their perceptions of parental distress over these problems, and parents' reports of their own distress over their adolescents' behaviors. Additionally, adolescents' perceived control over these behaviors was…

  15. Cognitive Load for Configuration Comprehension in Computer-Supported Geometry Problem Solving: An Eye Movement Perspective

    ERIC Educational Resources Information Center

    Lin, John Jr-Hung; Lin, Sunny S. J.

    2014-01-01

    The present study investigated (a) whether the perceived cognitive load was different when geometry problems with various levels of configuration comprehension were solved and (b) whether eye movements in comprehending geometry problems showed sources of cognitive loads. In the first investigation, three characteristics of geometry configurations…

  16. Cognitive Load for Configuration Comprehension in Computer-Supported Geometry Problem Solving: An Eye Movement Perspective

    ERIC Educational Resources Information Center

    Lin, John Jr-Hung; Lin, Sunny S. J.

    2014-01-01

    The present study investigated (a) whether the perceived cognitive load was different when geometry problems with various levels of configuration comprehension were solved and (b) whether eye movements in comprehending geometry problems showed sources of cognitive loads. In the first investigation, three characteristics of geometry configurations…

  17. Cone-Deciphered Modes of Problem Solving Action (MPSA Cone): Alternative Perspectives on Diversified Professions.

    ERIC Educational Resources Information Center

    Lai, Su-Huei

    A conceptual framework of the modes of problem-solving action has been developed on the basis of a simple relationship cone to assist individuals in diversified professions in inquiry and implementation of theory and practice in their professional development. The conceptual framework is referred to as the Cone-Deciphered Modes of Problem Solving…

  18. Saudi English-Major Undergraduates' Academic Writing Problems: A Taif University Perspective

    ERIC Educational Resources Information Center

    Al-Khairy, Mohamed Ali

    2013-01-01

    This study attempted to investigate Saudi English-major undergraduates studying at Taif University to identify a) the types of academic writing Saudi English-major undergraduates carry out at English departments, b) Saudi English-major undergraduates' writing problems, c) the reasons behind Saudi English-major undergraduates' writing problems and…

  19. Solving the Teacher Shortage Problem in Ghana: Critical Perspectives for Understanding the Issues

    ERIC Educational Resources Information Center

    Cobbold, Cosmas

    2015-01-01

    The problem of getting sufficient numbers of qualified teachers to staff classrooms is one of the most significant public policy issues facing many countries. In Ghana, the problem of teacher shortage has been a perennial one, necessitated by educational expansion as well as adverse socio-economic and political circumstances, and exacerbated by…

  20. Self-and Peer Perspectives on Pathological Personality Traits and Interpersonal Problems

    ERIC Educational Resources Information Center

    Clifton, Allan; Turkheimer, Eric; Oltmanns, Thomas F.

    2005-01-01

    This study compares the relationship between personality disorders and interpersonal problems as obtained by self-report and peer-report measures. Participants (N=393) were administered self-and peer-report versions of the Peer Inventory for Personality Disorder and the Inventory of Interpersonal Problems-64. Canonical analyses demonstrated…

  1. Developing Physics Concepts through Hands-On Problem Solving: A Perspective on a Technological Project Design

    ERIC Educational Resources Information Center

    Hong, Jon-Chao; Chen, Mei-Yung; Wong, Ashley; Hsu, Tsui-Fang; Peng, Chih-Chi

    2012-01-01

    In a contest featuring hands-on projects, college students were required to design a simple crawling worm using planning, self-monitoring and self-evaluation processes to solve contradictive problems. To enhance the efficiency of problem solving, one needs to practice meta-cognition based on an application of related scientific concepts. The…

  2. Developing Physics Concepts through Hands-On Problem Solving: A Perspective on a Technological Project Design

    ERIC Educational Resources Information Center

    Hong, Jon-Chao; Chen, Mei-Yung; Wong, Ashley; Hsu, Tsui-Fang; Peng, Chih-Chi

    2012-01-01

    In a contest featuring hands-on projects, college students were required to design a simple crawling worm using planning, self-monitoring and self-evaluation processes to solve contradictive problems. To enhance the efficiency of problem solving, one needs to practice meta-cognition based on an application of related scientific concepts. The…

  3. Problems and Perspectives on the Evaluation of Regional and National Computer-Related Educational Activity.

    ERIC Educational Resources Information Center

    Collis, Betty

    Although the importance of systematic evaluation of educational policy and practice is well established, various problems confound the intention of evaluating regional or national activity with regard to computer-related activities in education. At least two of these problems relate to a general conception of the appropriate entry points for…

  4. Valuation of Child Behavioral Problems from the Perspective of US Adults

    PubMed Central

    Craig, Benjamin M.; Brown, Derek S.; Reeve, Bryce B.

    2015-01-01

    OBJECTIVE To assess preferences between child behavioral problems and estimate their value on a quality-adjusted life year (QALYs) scale. METHODS Respondents, age 18 or older, drawn from a nationally representative panel between August 2012 and February 2013 completed a series of paired comparisons, each involving a choice between 2 different behavioral problems described using the Behavioral Problems Index (BPI), a 28-item instrument with 6 domains (Anxious/Depressed, Headstrong, Hyperactive, Immature Dependency, Anti-social, and Peer Conflict/Social Withdrawal). Each behavioral problem lasted 1 or 2 years for an unnamed child, age 7 or 10 years, with no suggested relationship to the respondent. Generalized linear model analyses estimated the value of each problem on a QALY scale, considering its duration and child’s age. RESULTS Among 5207 eligible respondents, 4155 (80%) completed all questions. Across the 6 domains, problems relating to antisocial behavior were the least preferred, particularly the items related to cheating, lying, bullying, and cruelty to others. CONCLUSIONS The findings are the first to produce a preference-based summary measure of child behavioral problems on a QALY scale. The results may inform both clinical practice and resource allocation decisions by enhancing our understanding of difficult tradeoffs in how adults view child behavioral problems. Understanding US values also promotes national health surveillance by complementing conventional measures of surveillance, survival, and diagnoses. PMID:26209476

  5. Fusion proteins as alternate crystallization paths to difficult structure problems

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C.; Rueker, Florian; Ho, Joseph X.; Lim, Kap; Keeling, Kim; Gilliland, Gary; Ji, Xinhua

    1994-01-01

    The three-dimensional structure of a peptide fusion product with glutathione transferase from Schistosoma japonicum (SjGST) has been solved by crystallographic methods to 2.5 A resolution. Peptides or proteins can be fused to SjGST and expressed in a plasmid for rapid synthesis in Escherichia coli. Fusion proteins created by this commercial method can be purified rapidly by chromatography on immobilized glutathione. The potential utility of using SjGST fusion proteins as alternate paths to the crystallization and structure determination of proteins is demonstrated.

  6. A Developmental Perspective on Peer Rejection, Deviant Peer Affiliation, and Conduct Problems Among Youth.

    PubMed

    Chen, Diane; Drabick, Deborah A G; Burgers, Darcy E

    2015-12-01

    Peer rejection and deviant peer affiliation are linked consistently to the development and maintenance of conduct problems. Two proposed models may account for longitudinal relations among these peer processes and conduct problems: the (a) sequential mediation model, in which peer rejection in childhood and deviant peer affiliation in adolescence mediate the link between early externalizing behaviors and more serious adolescent conduct problems; and (b) parallel process model, in which peer rejection and deviant peer affiliation are considered independent processes that operate simultaneously to increment risk for conduct problems. In this review, we evaluate theoretical models and evidence for associations among conduct problems and (a) peer rejection and (b) deviant peer affiliation. We then consider support for the sequential mediation and parallel process models. Next, we propose an integrated model incorporating both the sequential mediation and parallel process models. Future research directions and implications for prevention and intervention efforts are discussed.

  7. A Developmental Perspective on Peer Rejection, Deviant Peer Affiliation, and Conduct Problems among Youth

    PubMed Central

    Chen, Diane; Drabick, Deborah A. G.; Burgers, Darcy E.

    2015-01-01

    Peer rejection and deviant peer affiliation are linked consistently to the development and maintenance of conduct problems. Two proposed models may account for longitudinal relations among these peer processes and conduct problems: the (a) sequential mediation model, in which peer rejection in childhood and deviant peer affiliation in adolescence mediate the link between early externalizing behaviors and more serious adolescent conduct problems; and (b) parallel process model, in which peer rejection and deviant peer affiliation are considered independent processes that operate simultaneously to increment risk for conduct problems. In this review, we evaluate theoretical models and evidence for associations among conduct problems and (a) peer rejection and (b) deviant peer affiliation. We then consider support for the sequential mediation and parallel process models. Next, we propose an integrated model incorporating both the sequential mediation and parallel process models. Future research directions and implications for prevention and intervention efforts are discussed. PMID:25410430

  8. Family structure instability and mobility: The consequences for adolescents' problem behavior.

    PubMed

    Fomby, Paula; Sennott, Christie A

    2013-01-01

    Adolescents who experience changes in parents' union status are more likely than adolescents in stable family structures to engage in problem behavior. We ask whether the link between family structure transitions and problem behavior in adolescence may be explained in part by the residential and school mobility that co-occur with family structure change. Our analysis uses nationally-representative data from a two-generation study to assess the relative effects of family instability and mobility on the self-reported problem behavior of adolescents who were 12-17years old in 2006. Residential and school mobility only minimally attenuate the association of family structure changes with behavior problems for younger girls and older adolescents. Exposure to peer pressure has a larger attenuating effect. We conclude that although mobility often co-occurs with family structure change, it has independent effects on problem behavior. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Active Women: Perspectives on Their Structural Position in the Community.

    ERIC Educational Resources Information Center

    Moyer, Harriett; And Others

    An exploratory pilot study to determine the personal characteristics of women community leaders and their position in the power structure was conducted in Chippewa and Eau Claire Counties, Wisconsin. The research design involved a comparison of three samples: the traditional power structure identified through reputational techniques; the active…

  10. Advances in understanding glycosyltransferases from a structural perspective

    PubMed Central

    Gloster, Tracey M

    2014-01-01

    Glycosyltransferases (GTs), the enzymes that catalyse glycosidic bond formation, create a diverse range of saccharides and glycoconjugates in nature. Understanding GTs at the molecular level, through structural and kinetic studies, is important for gaining insights into their function. In addition, this understanding can help identify those enzymes which are involved in diseases, or that could be engineered to synthesize biologically or medically relevant molecules. This review describes how structural data, obtained in the last 3–4 years, have contributed to our understanding of the mechanisms of action and specificity of GTs. Particular highlights include the structure of a bacterial oligosaccharyltransferase, which provides insights into N-linked glycosylation, the structure of the human O-GlcNAc transferase, and the structure of a bacterial integral membrane protein complex that catalyses the synthesis of cellulose, the most abundant organic molecule in the biosphere. PMID:25240227

  11. A Structure-Agency Perspective on Young Children's Engagement in School Science: Carlos's Performance and Narrative

    ERIC Educational Resources Information Center

    Varelas, Maria; Tucker-Raymond, Eli; Richards, Kimberly

    2015-01-01

    Guided by sociological perspectives that view (young) children as agents who are shaped by and shape the structures of social systems in which they live, we studied forms that agency of young children from historically marginalized groups may take in science class when offered opportunities to engage in science in a variety of ways, how curricular…

  12. A Structure-Agency Perspective on Young Children's Engagement in School Science: Carlos's Performance and Narrative

    ERIC Educational Resources Information Center

    Varelas, Maria; Tucker-Raymond, Eli; Richards, Kimberly

    2015-01-01

    Guided by sociological perspectives that view (young) children as agents who are shaped by and shape the structures of social systems in which they live, we studied forms that agency of young children from historically marginalized groups may take in science class when offered opportunities to engage in science in a variety of ways, how curricular…

  13. Cognitive Structures of the Gifted: Theoretical Perspectives, Factor Analysis, Triarchic Theories of Intelligence, and Insight Issues.

    ERIC Educational Resources Information Center

    Shaughnessy, Michael F.

    The paper reviews research on the cognitive structures of gifted students. Theories of R. Sternberg and his triarchic model of intelligence are described. Sternberg asserts that three processes appear to account for insight: selective encoding, selective combination, and selective comparison. H. Gardner's perspective citing six types of…

  14. Atomic and Molecular Structure in Chemical Education: A Critical Analysis from Various Perspectives of Science Education.

    ERIC Educational Resources Information Center

    Tsaparlis, Georgios

    1997-01-01

    Provides a critical analysis of the role that atomic theory plays in the science curriculum from elementary through secondary school. Examines structural concepts from the perspective of the theory of meaningful learning, information processing theory, and the alternative conceptions movement. Contains 54 references. (DDR)

  15. The University of Wisconsin-Madison's Perspectives on Nuclear War: Goals, Organization and Structure.

    ERIC Educational Resources Information Center

    Ringler, Dick

    1983-01-01

    "Perspectives on Nuclear War" is an interdisciplinary course offered at the University of Wisconsin-Madison on an experimental basis during the 1981-82 academic year. Course scope/structure (including lecture schedule), readings, and requirements are provided. Suggests that similar courses should be developed and installed in curricula…

  16. Theoretical Borderlands: Using Multiple Theoretical Perspectives to Challenge Inequitable Power Structures in Student Development Theory

    ERIC Educational Resources Information Center

    Abes, Elisa S.

    2009-01-01

    This article is an exploration of possibilities and methodological considerations for using multiple theoretical perspectives in research that challenges inequitable power structures in student development theory. Specifically, I explore methodological considerations when partnering queer theory and constructivism in research on lesbian identity…

  17. Atomic and Molecular Structure in Chemical Education: A Critical Analysis from Various Perspectives of Science Education.

    ERIC Educational Resources Information Center

    Tsaparlis, Georgios

    1997-01-01

    Provides a critical analysis of the role that atomic theory plays in the science curriculum from elementary through secondary school. Examines structural concepts from the perspective of the theory of meaningful learning, information processing theory, and the alternative conceptions movement. Contains 54 references. (DDR)

  18. Extending the Multiple-Goal Perspective to Tertiary Classroom Goal Structures

    ERIC Educational Resources Information Center

    James, Vennessa H.; Yates, Shirley M.

    2007-01-01

    The multiple-goal perspective has recently been applied to teacher behaviours in primary school classrooms through experimental intervention (Linnenbrink, 2005) and objective observation (Sideridis, 2005). However, there is evidence suggesting that rather than centered only on teacher behaviour, classroom goal structures are a whole class feature…

  19. Influence of Height in Simulation of Soil Structure Interaction Problems with Dampers

    NASA Astrophysics Data System (ADS)

    Bogdanovic, Aleksandra; Edip, Kemal; Stojmanovska, Marta

    2016-12-01

    In numerical simulation of soil structure interaction problems the presence of dampers in the frame is an advantage yet a special topic to be considered. This paper presents valuable observation on the dynamic soil structure interaction analysis of multi storey frames and considers the effect of height in simulation of soil structure interaction problems. Comparison of these problems has been done by comparing the obtained results from different set up in the software ANSYS. The results of numerical analysis illustrate that it has to be paid more attention when considering the structures not alone but also considering the effect of soil medium.

  20. Bioinformatics and variability in drug response: a protein structural perspective

    PubMed Central

    Lahti, Jennifer L.; Tang, Grace W.; Capriotti, Emidio; Liu, Tianyun; Altman, Russ B.

    2012-01-01

    Marketed drugs frequently perform worse in clinical practice than in the clinical trials on which their approval is based. Many therapeutic compounds are ineffective for a large subpopulation of patients to whom they are prescribed; worse, a significant fraction of patients experience adverse effects more severe than anticipated. The unacceptable risk–benefit profile for many drugs mandates a paradigm shift towards personalized medicine. However, prior to adoption of patient-specific approaches, it is useful to understand the molecular details underlying variable drug response among diverse patient populations. Over the past decade, progress in structural genomics led to an explosion of available three-dimensional structures of drug target proteins while efforts in pharmacogenetics offered insights into polymorphisms correlated with differential therapeutic outcomes. Together these advances provide the opportunity to examine how altered protein structures arising from genetic differences affect protein–drug interactions and, ultimately, drug response. In this review, we first summarize structural characteristics of protein targets and common mechanisms of drug interactions. Next, we describe the impact of coding mutations on protein structures and drug response. Finally, we highlight tools for analysing protein structures and protein–drug interactions and discuss their application for understanding altered drug responses associated with protein structural variants. PMID:22552919

  1. Insulin-Like Growth Factor Binding Proteins: A Structural Perspective

    PubMed Central

    Forbes, Briony E.; McCarthy, Peter; Norton, Raymond S.

    2012-01-01

    Insulin-like growth factor binding proteins (IGFBP-1 to -6) bind insulin-like growth factors-I and -II (IGF-I and IGF-II) with high affinity. These binding proteins maintain IGFs in the circulation and direct them to target tissues, where they promote cell growth, proliferation, differentiation, and survival via the type 1 IGF receptor. IGFBPs also interact with many other molecules, which not only influence their modulation of IGF action but also mediate IGF-independent activities that regulate processes such as cell migration and apoptosis by modulating gene transcription. IGFBPs-1 to -6 are structurally similar proteins consisting of three distinct domains, N-terminal, linker, and C-terminal. There have been major advances in our understanding of IGFBP structure in the last decade and a half. While there is still no structure of an intact IGFBP, several structures of individual N- and C-domains have been solved. The structure of a complex of N-BP-4:IGF-I:C-BP-4 has also been solved, providing a detailed picture of the structural features of the IGF binding site and the mechanism of binding. Structural studies have also identified features important for interaction with extracellular matrix components and integrins. This review summarizes structural studies reported so far and highlights features important for binding not only IGF but also other partners. We also highlight future directions in which structural studies will add to our knowledge of the role played by the IGFBP family in normal growth and development, as well as in disease. PMID:22654863

  2. NASA Langley's Approach to the Sandia's Structural Dynamics Challenge Problem

    NASA Technical Reports Server (NTRS)

    Horta, Lucas G.; Kenny, Sean P.; Crespo, Luis G.; Elliott, Kenny B.

    2007-01-01

    The objective of this challenge is to develop a data-based probabilistic model of uncertainty to predict the behavior of subsystems (payloads) by themselves and while coupled to a primary (target) system. Although this type of analysis is routinely performed and representative of issues faced in real-world system design and integration, there are still several key technical challenges that must be addressed when analyzing uncertain interconnected systems. For example, one key technical challenge is related to the fact that there is limited data on target configurations. Moreover, it is typical to have multiple data sets from experiments conducted at the subsystem level, but often samples sizes are not sufficient to compute high confidence statistics. In this challenge problem additional constraints are placed as ground rules for the participants. One such rule is that mathematical models of the subsystem are limited to linear approximations of the nonlinear physics of the problem at hand. Also, participants are constrained to use these models and the multiple data sets to make predictions about the target system response under completely different input conditions. Our approach involved initially the screening of several different methods. Three of the ones considered are presented herein. The first one is based on the transformation of the modal data to an orthogonal space where the mean and covariance of the data are matched by the model. The other two approaches worked solutions in physical space where the uncertain parameter set is made of masses, stiffnesses and damping coefficients; one matches confidence intervals of low order moments of the statistics via optimization while the second one uses a Kernel density estimation approach. The paper will touch on all the approaches, lessons learned, validation 1 metrics and their comparison, data quantity restriction, and assumptions/limitations of each approach. Keywords: Probabilistic modeling, model validation

  3. [Representation and structure from a developmental psychopathology perspective].

    PubMed

    Resch, F

    1999-10-01

    An attempt to define "psychic structure" leads to the conclusion, that "structure" provides adaptive behavioral strategies for the interaction of the person with a physical and social world by representing experiences of earlier interactions in memory processes. Compatibility of different definitions of "structure" in psychopathology and psychoanalysis is being discussed. Developmental aspects of a "theory of mind" in children and of different modes of representation have to be addressed. A "multiple code theory" of W. Bucci is introduced. Conclusions for diagnosis and therapy in psychodynamic approaches will be drawn. It has to be faced, that children represent optimal structures in each level of psychic development, noting the importance of age-relevant normative measures.

  4. Prion protein and its conformational conversion: a structural perspective.

    PubMed

    Surewicz, Witold K; Apostol, Marcin I

    2011-01-01

    The key molecular event in the pathogenesis of prion diseases is the conformational conversion of a cellular prion protein, PrP(C), into a misfolded form, PrP(Sc). In contrast to PrP(C) that is monomeric and α-helical, PrP(Sc) is oligomeric in nature and rich in β-sheet structure. According to the "protein-only" model, PrP(Sc) itself represents the infectious prion agent responsible for transmissibility of prion disorders. While this model is supported by rapidly growing experimental data, detailed mechanistic and structural aspects of prion protein conversion remain enigmatic. In this chapter we describe recent advances in understanding biophysical and biochemical aspects of prion diseases, with a special focus on structural underpinnings of prion protein conversion, the structural basis of prion strains, and generation of prion infectivity in vitro from bacterially-expressed recombinant PrP.

  5. Parent and teacher perspectives about problem behavior in children with Williams syndrome.

    PubMed

    Klein-Tasman, Bonita P; Lira, Ernesto N; Li-Barber, Kirsten T; Gallo, Frank J; Brei, Natalie G

    2015-01-01

    Problem behavior of 52 children with Williams syndrome ages 6 to 17 years old was examined based on both parent and teacher report. Generally good inter-rater agreement was found. Common areas of problem behavior based both on parent and teacher report included attention problems, anxiety difficulties, repetitive behaviors (e.g., obsessions, compulsions, picking nose or skin), and social problems, reflecting a robust behavioral phenotype in Williams syndrome present across contexts. Some rater differences were observed; most notably, parents reported more attention and mood difficulties than did teachers, while teachers reported more oppositionality and aggression than did parents. Relations to intellectual functioning, age, and gender were examined. The implications of the findings for understanding the behavioral phenotype associated with Williams syndrome are discussed.

  6. Hydrological problems of water resources in irrigated agriculture: A management perspective

    NASA Astrophysics Data System (ADS)

    Singh, Ajay

    2016-10-01

    The development of irrigated agriculture is necessary for fulfilling the rising food requirements of the burgeoning global population. However, the intensification of irrigated agriculture causes the twin menace of waterlogging and soil salinization in arid and semiarid regions where more than 75% of the world's population lives. These problems can be managed by either adopting preventive measures which decrease the inflow of water and salt or by employing remedial measures which increase the outflow. This paper presents an overview of various measures used for the management of waterlogging and salinity problems. The background, processes involved, and severity of waterlogging and salinity problems are provided. The role of drainage systems, conjunctive use of different water sources, use of computer-based mathematical models, and the use of remote sensing and GIS techniques in managing the problems are discussed. Conclusions are provided which could be useful for all the stakeholders.

  7. Perspectives for the structure-based design of acetylcholinesterase reactivators.

    PubMed

    Ochoa, Rodrigo; Rodriguez, Carlos A; Zuluaga, Andres F

    2016-07-01

    Rational design of active molecules through structure-based methods has been gaining adepts during the last decades due to the wider availability of protein structures, most of them conjugated with relevant ligands. Acetylcholinesterase (AChE) is a molecular target with a considerable amount of data related to its sequence and 3-dimensional structure. In addition, there are structural insights about the mechanism of action of the natural substrate and drugs used in Alzheimer's disease, organophosphorus compounds, among others. We looked for AChE structural data useful for in silico design of potential interacting molecules. In particular, we focused on information regarding the design of ligands aimed to reactivate AChE catalytic activity. The structures of 178 AChE were annotated and categorized on different subsets according to the nature of the ligand, source organisms and experimental details. We compared sequence homology among the active site from Torpedo californica, Mus musculus and Homo sapiens with the latter two species having the closest relationship (88.9% identity). In addition, the mechanism of organophosphorus binding and the design of effective reactivators are reviewed. A curated data collection obtained with information from several sources was included for researchers working on the field. Finally, a molecular dynamics simulation with human AChE indicated that the catalytic pocket volume stabilizes around 600 Å(3), providing additional clues for drug design.

  8. The Quality of High School Students' Problem Solving from an Expertise Development Perspective

    ERIC Educational Resources Information Center

    Elvira, Quincy; Imants, Jeroen; deMaeyer, Sven; Segers, Mien

    2015-01-01

    The ability to solve problems is a key skill and is essential to our day-to-day lives, at home, at school and at work. The present study explores the quality of managerial problem-solving of participants who are in secondary education. We studied 10th, 11th, and 12th graders following a business track in the Netherlands. Participants were asked to…

  9. The growing problems of dental caries and obesity: an Australian perspective.

    PubMed

    Hopcraft, M S; Beaumont, S

    2016-10-07

    Preventable diet-related diseases such as dental caries and obesity are a growing global problem, causing a significant burden on public health systems. Although there has been good evidence for the links between sugar consumption and dental caries for many decades, we are now seeing stronger links implicating sugar in obesity. There is a growing worldwide movement to tackle these problems by targeting the consumption of sugar-sweetened beverages through a range of public policy measures.

  10. The Quality of High School Students' Problem Solving from an Expertise Development Perspective

    ERIC Educational Resources Information Center

    Elvira, Quincy; Imants, Jeroen; deMaeyer, Sven; Segers, Mien

    2015-01-01

    The ability to solve problems is a key skill and is essential to our day-to-day lives, at home, at school and at work. The present study explores the quality of managerial problem-solving of participants who are in secondary education. We studied 10th, 11th, and 12th graders following a business track in the Netherlands. Participants were asked to…

  11. Effects of a Problem-based Structure of Physics Contents on Conceptual Learning and the Ability to Solve Problems

    NASA Astrophysics Data System (ADS)

    Becerra-Labra, Carlos; Gras-Martí, Albert; Martínez Torregrosa, Joaquín

    2012-05-01

    A model of teaching/learning is proposed based on a 'problem-based structure' of the contents of the course, in combination with a training in paper and pencil problem solving that emphasizes discussion and quantitative analysis, rather than formulae plug-in. The aim is to reverse the high failure and attrition rate among engineering undergraduates taking physics. A number of tests and questionnaires were administered to a group of students following a traditional lecture-based instruction, as well as to another group that was following an instruction scheme based on the proposed approach and the teaching materials developed ad hoc. The results show that students following the new method can develop scientific reasoning habits in problem-solving skills, and show gains in conceptual learning, attitudes and interests, and that the effects of this approach on learning are noticeable several months after the course is over.

  12. Zika Virus Methyltransferase: Structure and Functions for Drug Design Perspectives.

    PubMed

    Coutard, Bruno; Barral, Karine; Lichière, Julie; Selisko, Barbara; Martin, Baptiste; Aouadi, Wahiba; Lombardia, Miguel Ortiz; Debart, Françoise; Vasseur, Jean-Jacques; Guillemot, Jean Claude; Canard, Bruno; Decroly, Etienne

    2017-03-01

    The Flavivirus Zika virus (ZIKV) is the causal agent of neurological disorders like microcephaly in newborns or Guillain-Barre syndrome. Its NS5 protein embeds a methyltransferase (MTase) domain involved in the formation of the viral mRNA cap. We investigated the structural and functional properties of the ZIKV MTase. We show that the ZIKV MTase can methylate RNA cap structures at the N-7 position of the cap, and at the 2'-O position on the ribose of the first nucleotide, yielding a cap-1 structure. In addition, the ZIKV MTase methylates the ribose 2'-O position of internal adenosines of RNA substrates. The crystal structure of the ZIKV MTase determined at a 2.01-Å resolution reveals a crystallographic homodimer. One chain is bound to the methyl donor (S-adenosyl-l-methionine [SAM]) and shows a high structural similarity to the dengue virus (DENV) MTase. The second chain lacks SAM and displays conformational changes in the αX α-helix contributing to the SAM and RNA binding. These conformational modifications reveal a possible molecular mechanism of the enzymatic turnover involving a conserved Ser/Arg motif. In the second chain, the SAM binding site accommodates a sulfate close to a glycerol that could serve as a basis for structure-based drug design. In addition, compounds known to inhibit the DENV MTase show similar inhibition potency on the ZIKV MTase. Altogether these results contribute to a better understanding of the ZIKV MTase, a central player in viral replication and host innate immune response, and lay the basis for the development of potential antiviral drugs.IMPORTANCE The Zika virus (ZIKV) is associated with microcephaly in newborns, and other neurological disorders such as Guillain-Barre syndrome. It is urgent to develop antiviral strategies inhibiting the viral replication. The ZIKV NS5 embeds a methyltransferase involved in the viral mRNA capping process, which is essential for viral replication and control of virus detection by innate immune

  13. Zika Virus Methyltransferase: Structure and Functions for Drug Design Perspectives

    PubMed Central

    Coutard, Bruno; Barral, Karine; Lichière, Julie; Selisko, Barbara; Martin, Baptiste; Aouadi, Wahiba; Lombardia, Miguel Ortiz; Debart, Françoise; Vasseur, Jean-Jacques; Guillemot, Jean Claude; Canard, Bruno

    2016-01-01

    ABSTRACT The Flavivirus Zika virus (ZIKV) is the causal agent of neurological disorders like microcephaly in newborns or Guillain-Barre syndrome. Its NS5 protein embeds a methyltransferase (MTase) domain involved in the formation of the viral mRNA cap. We investigated the structural and functional properties of the ZIKV MTase. We show that the ZIKV MTase can methylate RNA cap structures at the N-7 position of the cap, and at the 2′-O position on the ribose of the first nucleotide, yielding a cap-1 structure. In addition, the ZIKV MTase methylates the ribose 2′-O position of internal adenosines of RNA substrates. The crystal structure of the ZIKV MTase determined at a 2.01-Å resolution reveals a crystallographic homodimer. One chain is bound to the methyl donor (S-adenosyl-l-methionine [SAM]) and shows a high structural similarity to the dengue virus (DENV) MTase. The second chain lacks SAM and displays conformational changes in the αX α-helix contributing to the SAM and RNA binding. These conformational modifications reveal a possible molecular mechanism of the enzymatic turnover involving a conserved Ser/Arg motif. In the second chain, the SAM binding site accommodates a sulfate close to a glycerol that could serve as a basis for structure-based drug design. In addition, compounds known to inhibit the DENV MTase show similar inhibition potency on the ZIKV MTase. Altogether these results contribute to a better understanding of the ZIKV MTase, a central player in viral replication and host innate immune response, and lay the basis for the development of potential antiviral drugs. IMPORTANCE The Zika virus (ZIKV) is associated with microcephaly in newborns, and other neurological disorders such as Guillain-Barre syndrome. It is urgent to develop antiviral strategies inhibiting the viral replication. The ZIKV NS5 embeds a methyltransferase involved in the viral mRNA capping process, which is essential for viral replication and control of virus detection by

  14. Structural problems of the Brooks Range ophiolite, Alaska

    SciTech Connect

    Harris, R.A.; Bickerstaff, D. . Dept. of Geology); Stone, D.B. . Geophysical Inst.)

    1993-04-01

    Structural and paleogeographic restorations of the Brooks Range ophiolite (hereafter BRO) and other associated mafic and ultramafic bodies of N. Alaska are difficult because of ambiguous relations between sheeted dikes, cover sediments, and steep NW and SE dipping magmatic flow fabrics. Paleomagnetically enhanced structural studies at Misheguk, Avan, and Siniktanneyak Mountains provide new constraints for the initial dip and sequence of deformation for various structural features of the BRO. The angle between magmatic layers near the petrologic moho and the paleomagnetic inclination of these layers is 50--63[degree] at Misheguk. High level gabbro layers that are disrupted by syn- and post-cooling intrusions display a greater variation. Assuming that the characteristic magnetization is primary, and that the primary inclination was > 80[degree], magmatic layers and the moho had initial dips from 17--40[degree]. These layers now dip 40--70[degree]SE suggesting some post-magmatic tilt. The variation of inclinations with depth in the ophiolite suggest that high level gabbro has tilted most. Sheeted dikes are documented at the Maiyumerak and Siniktanneyak ophiolite bodies. At both locations the dikes dip steeply and strike NE-SW. Sedimentary and volcanic flow layers associated with the dikes have the same strike and dip 0--30[degree]. Parallelism between various planar features throughout the BRO indicates that rotations about a vertical axis are either uniform throughout the ophiolite belt or negligible. Assuming the later, the BRO may represent a linear zone of SSZ magmatism that was oriented NE-SW prior to collision. Post-emplacement long wavelength folding of the ophiolite lid can account for its variation in facing direction and some steepening of magmatic layers.

  15. Structure preserving parallel algorithms for solving the Bethe–Salpeter eigenvalue problem

    SciTech Connect

    Shao, Meiyue; da Jornada, Felipe H.; Yang, Chao; Deslippe, Jack; Louie, Steven G.

    2015-10-02

    The Bethe–Salpeter eigenvalue problem is a dense structured eigenvalue problem arising from discretized Bethe–Salpeter equation in the context of computing exciton energies and states. A computational challenge is that at least half of the eigenvalues and the associated eigenvectors are desired in practice. In this paper, we establish the equivalence between Bethe–Salpeter eigenvalue problems and real Hamiltonian eigenvalue problems. Based on theoretical analysis, structure preserving algorithms for a class of Bethe–Salpeter eigenvalue problems are proposed. We also show that for this class of problems all eigenvalues obtained from the Tamm–Dancoff approximation are overestimated. In order to solve large scale problems of practical interest, we discuss parallel implementations of our algorithms targeting distributed memory systems. Finally, several numerical examples are presented to demonstrate the efficiency and accuracy of our algorithms.

  16. Narcissism as a motivational structure: the problem of personal significance.

    PubMed

    Shaw, J A

    2000-01-01

    An understanding of individual life is contingent on understanding not only man's traditional motivations but also the individual strategy for resolving the problem of personal insignificance. Man's sense of personal insignificance comes from two primary experiences: (a) the developmental experience with its increasing awareness of separation and loss, transience, and the sense of lost felt perfectibility; and (b) the increasing cognitive awareness of the immutable laws of biology and the limitations of the self and others in which idealization gives way to painful reality. Each individual seeks narcissistic reparation through the elaboration of a personal narrative or myth, a story, which gives one's life a feeling of personal significance, meaning, and purpose. What is relevant is not the presence or absence of a myth or personal narrative but within which myth one chooses to live one's life. Myths are not explanations rooted in scientific evidence but rather are belief systems lived as if they were truths. Myths provide the individual with a personal sense of identity, and they confirm and affirm memberships in a group or community, and provide guidelines and an idealized set of behaviors within which to operate. Lastly, they may endorse an explanation for the mysterious universe. Three motivational strategies in which the aim is to create a personal myth or personal narrative that ensures a sense of personal significance are described in this article: (a) transcendental or spiritual myths, (b) group or interpersonal myths, and (c) humanistic or personal myths.

  17. Perspective: Structure and ultrafast dynamics of biomolecular hydration shells

    PubMed Central

    Laage, Damien; Elsaesser, Thomas; Hynes, James T.

    2017-01-01

    The structure and function of biomolecules can be strongly influenced by their hydration shells. A key challenge is thus to determine the extent to which these shells differ from bulk water, since the structural fluctuations and molecular excitations of hydrating water molecules within these shells can cover a broad range in both space and time. Recent progress in theory, molecular dynamics simulations, and ultrafast vibrational spectroscopy has led to new and detailed insight into the fluctuations of water structure, elementary water motions, and electric fields at hydrated biointerfaces. Here, we discuss some central aspects of these advances, focusing on elementary molecular mechanisms and processes of hydration on a femto- to picosecond time scale, with some special attention given to several issues subject to debate. PMID:28470026

  18. Illuminating the dark matter of social neuroscience: Considering the problem of social interaction from philosophical, psychological, and neuroscientific perspectives

    PubMed Central

    Przyrembel, Marisa; Smallwood, Jonathan; Pauen, Michael; Singer, Tania

    2012-01-01

    Successful human social interaction depends on our capacity to understand other people's mental states and to anticipate how they will react to our actions. Despite its importance to the human condition, the exact mechanisms underlying our ability to understand another's actions, feelings, and thoughts are still a matter of conjecture. Here, we consider this problem from philosophical, psychological, and neuroscientific perspectives. In a critical review, we demonstrate that attempts to draw parallels across these complementary disciplines is premature: The second-person perspective does not map directly to Interaction or Simulation theories, online social cognition, or shared neural network accounts underlying action observation or empathy. Nor does the third-person perspective map onto Theory-Theory (TT), offline social cognition, or the neural networks that support Theory of Mind (ToM). Moreover, we argue that important qualities of social interaction emerge through the reciprocal interplay of two independent agents whose unpredictable behavior requires that models of their partner's internal state be continually updated. This analysis draws attention to the need for paradigms in social neuroscience that allow two individuals to interact in a spontaneous and natural manner and to adapt their behavior and cognitions in a response contingent fashion due to the inherent unpredictability in another person's behavior. Even if such paradigms were implemented, it is possible that the specific neural correlates supporting such reciprocal interaction would not reflect computation unique to social interaction but rather the use of basic cognitive and emotional processes combined in a unique manner. Finally, we argue that given the crucial role of social interaction in human evolution, ontogeny, and every-day social life, a more theoretically and methodologically nuanced approach to the study of real social interaction will nevertheless help the field of social cognition

  19. Illuminating the dark matter of social neuroscience: Considering the problem of social interaction from philosophical, psychological, and neuroscientific perspectives.

    PubMed

    Przyrembel, Marisa; Smallwood, Jonathan; Pauen, Michael; Singer, Tania

    2012-01-01

    Successful human social interaction depends on our capacity to understand other people's mental states and to anticipate how they will react to our actions. Despite its importance to the human condition, the exact mechanisms underlying our ability to understand another's actions, feelings, and thoughts are still a matter of conjecture. Here, we consider this problem from philosophical, psychological, and neuroscientific perspectives. In a critical review, we demonstrate that attempts to draw parallels across these complementary disciplines is premature: The second-person perspective does not map directly to Interaction or Simulation theories, online social cognition, or shared neural network accounts underlying action observation or empathy. Nor does the third-person perspective map onto Theory-Theory (TT), offline social cognition, or the neural networks that support Theory of Mind (ToM). Moreover, we argue that important qualities of social interaction emerge through the reciprocal interplay of two independent agents whose unpredictable behavior requires that models of their partner's internal state be continually updated. This analysis draws attention to the need for paradigms in social neuroscience that allow two individuals to interact in a spontaneous and natural manner and to adapt their behavior and cognitions in a response contingent fashion due to the inherent unpredictability in another person's behavior. Even if such paradigms were implemented, it is possible that the specific neural correlates supporting such reciprocal interaction would not reflect computation unique to social interaction but rather the use of basic cognitive and emotional processes combined in a unique manner. Finally, we argue that given the crucial role of social interaction in human evolution, ontogeny, and every-day social life, a more theoretically and methodologically nuanced approach to the study of real social interaction will nevertheless help the field of social cognition

  20. PREDICTORS OF EMOTIONAL AND BEHAVIORAL PROBLEMS IN 1-YEAR-OLD CHILDREN: A LONGITUDINAL PERSPECTIVE.

    PubMed

    Sirvinskiene, Giedre; Zemaitiene, Nida; Jusiene, Roma; Markuniene, Egle

    2016-07-01

    Emotional and behavioral problems at an early age can reasonably be considered a high-risk factor for later mental health disorders. The aim of the article is to reveal predictive factors of 1½-year-old children's emotional and behavioral problems. The study was a part of a prospective birth-cohort study. The study sample consisted of 172 full-term infants (born during Gestational Weeks 37-42) and their mothers. Emotional and behavioral problems at the age of 1½ years were measured using the Child Behavior Checklist for Ages 1½-5 (T. Achenbach & L. Rescorla, 2000), which was completed by mothers. Emotional and behavioral problems at age of 1½ years were more prevalent in infants born via cesarean section, as compared to infants born vaginally without administration of medication. Newborns' suboptimal functioning after birth, complicated emotional acceptance of pregnancy, a couple's nonsatisfactory relationship during pregnancy, maternal distress during pregnancy and in the first months after childbirth, and inflexible and parent-oriented attitudes toward infant-rearing also predicted children's emotional and behavioral problems independent of sociodemographic factors. Results suggest that biomedical and psychosocial factors which manifest themselves in the prenatal and perinatal periods can have associations with later infant and child mental health. © 2016 Michigan Association for Infant Mental Health.

  1. Problems of providing services to people affected by HIV/AIDS: service providers and recipients perspectives.

    PubMed

    Moradi, G; Mohraz, M; Gouya, M M; Dejman, M; Alinaghi, S S; Rahmani, K; Malekafzali-Ardakani, H

    2015-02-25

    This qualitative study aimed to identify the health-care problems of people living with HIV (PLHIV) in 2 large cities: Tehran and Kermanshah. Two main groups of stakeholders - service providers (policy-makers, managers, physicians and counsellors) and service recipients (PLHIV and their relatives) - participated in focus group discussions and in-depth interviews. We identified 24 themes covering the major health problems of PLHIV, including: incomplete and inadequate coverage of health-care services; patients' substance abuse; patients' fear of stigma; occupational burnout of certain service providers; patients' dissatisfaction with some of the services provided by counselling centres/clinics; medical staff's failure to observe confidentiality; and patients' lack of access to required specialized services. The problems and needs identified can inform the design and implementation of health programmes in our country and elsewhere in the Eastern Mediterranean Region.

  2. Self- and Peer Perspectives on Pathological Personality Traits and Interpersonal Problems

    PubMed Central

    Clifton, Allan; Turkheimer, Eric; Oltmanns, Thomas F.

    2015-01-01

    This study compares the relationship between personality disorders and interpersonal problems as obtained by self-report and peer-report measures. Participants (N = 393) were administered self- and peer-report versions of the Peer Inventory for Personality Disorder and the Inventory of Interpersonal Problems–64. Canonical analyses demonstrated similar relationships between personality disorder features and interpersonal problems as measured by either self or peer. Analyses between self and peer found little shared variance across sources, indicating a large method variance. Results indicate that although similar constructs are identified by self and peers in their understanding of personality pathology and associated interpersonal problems, self-report information overlaps very little with information obtained from peers, underscoring the importance of obtaining multiple sources of information. PMID:16029099

  3. Research Articles in Applied Linguistics: Structures from a Functional Perspective

    ERIC Educational Resources Information Center

    Ruiying, Yang; Allison, Desmond

    2004-01-01

    This paper presents the main lines of a genre analysis of the macro-structures of research articles (RAs) in applied linguistics, an area that deserves more attention both for pedagogic and research reasons. The analysis is based upon a detailed study of a corpus of 40 RAs, selected as random sets of 10 drawn from four leading journals in the…

  4. Normative and Structural Perspectives on Age in a Work Organization.

    ERIC Educational Resources Information Center

    Lawrence, Barbara S.

    Age grading, the differentiation of social groups by members' age judgments, is widely regarded to be a universal aspect of social life. Most studies have examined age structurally (demographically), rather than normatively (modally). This study presents survey data measuring employees' age judgments of managerial careers collected from an…

  5. Human IgG4: a structural perspective

    PubMed Central

    Davies, Anna M; Sutton, Brian J

    2015-01-01

    IgG4, the least represented human IgG subclass in serum, is an intriguing antibody with unique biological properties, such as the ability to undergo Fab-arm exchange and limit immune complex formation. The lack of effector functions, such as antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity, is desirable for therapeutic purposes. IgG4 plays a protective role in allergy by acting as a blocking antibody, and inhibiting mast cell degranulation, but a deleterious role in malignant melanoma, by impeding IgG1-mediated anti-tumor immunity. These findings highlight the importance of understanding the interaction between IgG4 and Fcγ receptors. Despite a wealth of structural information for the IgG1 subclass, including complexes with Fcγ receptors, and structures for intact antibodies, high-resolution crystal structures were not reported for IgG4-Fc until recently. Here, we highlight some of the biological properties of human IgG4, and review the recent crystal structures of IgG4-Fc. We discuss the unexpected conformations adopted by functionally important Cγ2 domain loops, and speculate about potential implications for the interaction between IgG4 and FcγRs. PMID:26497518

  6. A Historical Perspective and Overview of Protein Structure Prediction

    NASA Astrophysics Data System (ADS)

    Wooley, John C.; Ye, Yuzhen

    Carrying on many different biological functions, proteins are all composed of one or more polypeptide chains, each containing from several to hundreds or even thousands of the 20 amino acids. During the 1950s at the dawn of modern biochemistry, an essential question for biochemists was to understand the structure and function of these polypeptide chains. The sequences of protein, also referred to as their primary structures, determine the different chemical properties for different proteins, and thus continue to captivate much of the attention of biochemists. As an early step in characterizing protein chemistry, British biochemist Frederick Sanger designed an experimental method to identify the sequence of insulin (Sanger et al., 1955). He became the first person to obtain the primary structure of a protein and in 1958 won his first Nobel Price in Chemistry. This important progress in sequencing did not answer the question of whether a single (individual) protein has a distinctive shape in three dimensions (3D), and if so, what factors determine its 3D architecture. However, during the period when Sanger was studying the primary structure of proteins, American biochemist Christian Anfinsen observed that the active polypeptide chain of a model protein, bovine pancreatic ribonuclease (RNase), could fold spontaneously into a unique 3D structure, which was later called native conformation of the protein (Anfinsen et al., 1954). Anfinsen also studied the refolding of RNase enzyme and observed that an enzyme unfolded under extreme chemical environment could refold spontaneously back into its native conformation upon changing the environment back to natural conditions (Anfinsen et al., 1961). By 1962, Anfinsen had developed his theory of protein folding (which was summarized in his 1972 Nobel acceptance speech): "The native conformation is determined by the totality of interatomic interactions and hence, by the amino acid sequence, in a given environment."

  7. The role of perspective information in the recovery of 3D structure-from-motion.

    PubMed

    Eagle, R A; Hogervorst, M A

    1999-05-01

    When investigating the recovery of three-dimensional structure-from-motion (SFM), vision scientists often assume that scaled-orthographic projection, which removes effects due to depth variations across the object, is an adequate approximation to full perspective projection. This is so even though SFM judgements can, in principle, be improved by exploiting perspective projection of scenes on to the retina. In an experiment, pairs of rotating hinged planes (open books) were simulated on a computer monitor, under either perspective or orthographic projection, and human observers were asked to indicate which they perceived had the larger dihedral angle. For small displays (4.6 x 6.0 degrees) discrimination thresholds were found to be similar under the two conditions, but diverged for all larger stimuli. In particular, as stimulus size was increased, performance under orthographic projection declined and by a stimulus size of 32 x 41 degrees performance was at chance for all subjects. In contrast, thresholds decreased under perspective projection as stimulus size was increased. These results show that human observers can use the information gained from perspective projection to recover SFM and that scaled-orthographic projection becomes an unacceptable approximation even at quite modest stimulus sizes. A model of SFM that incorporates measurement errors on the retinal motions accounts for performance under both projection systems, suggesting that this early noise forms the primary limitation on 3D discrimination performance.

  8. A public health perspective to environmental barriers and accessibility problems for senior citizens living in ordinary housing.

    PubMed

    Granbom, Marianne; Iwarsson, Susanne; Kylberg, Marianne; Pettersson, Cecilia; Slaug, Björn

    2016-08-11

    Housing environments that hinder performance of daily activities and impede participation in social life have negative health consequences particularly for the older segment of the population. From a public health perspective accessible housing that supports active and healthy ageing is therefore crucial. The objective of the present study was to make an inventory of environmental barriers and investigate accessibility problems in the ordinary housing stock in Sweden as related to the functional capacity of senior citizens. Particular attention was paid to differences between housing types and building periods and to identify environmental barriers generating the most accessibility problems for sub-groups of senior citizens. Data on environmental barriers in dwellings from three databases on housing and health in old age was analysed (N = 1021). Four functional profiles representing large groups of senior citizens were used in analyses of the magnitude and severity of potential accessibility problems. Differences in terms of type of housing and building period were examined. High proportions of one-family houses as well as multi-dwellings had substantial numbers of environmental barriers, with significantly lower numbers in later building periods. Accessibility problems occurred already for senior citizens with few functional limitations, but more profound for those dependent on mobility devices. The most problematic housing sections were entrances in one-family houses and kitchens of multi-dwellings. Despite a high housing standard in the Swedish ordinary housing stock the results show substantial accessibility problems for senior citizens with functional limitations. To make housing accessible large-scale and systematic efforts are required.

  9. [A historical-epistemological perspective of the ontological problem of Positivism. Positivism and psychiatry].

    PubMed

    Fantin, Juan Carlos

    2005-01-01

    The present article reviews epistemological problems related to the philosophical and scientific current known as Positivism. The revision begins with the study of the historical period during which the Logical Positivism emerges (early in the decade of 1920); and finishes with the analysis of its influence on psychiatry and its relation with other epistemological currents in the same period. The article reviews the historical and epistemological outlook at te beginning of the XX th century, when the problem of language became ontologically outstanding. The question of language remains important in the present discussions.

  10. A Conceptual Framework Mapping the Application of Information Search Strategies to Well and Ill-Structured Problem Solving

    ERIC Educational Resources Information Center

    Laxman, Kumar

    2010-01-01

    Problem-based learning (PBL) is an instructional approach that is organized around the investigation and resolution of problems. Problems are neither uniform nor similar. Jonassen (1997, 2000) in his design theory of problem solving has categorized problems into two broad types--well-structured and ill-structured. He has also described a host of…

  11. A Conceptual Framework Mapping the Application of Information Search Strategies to Well and Ill-Structured Problem Solving

    ERIC Educational Resources Information Center

    Laxman, Kumar

    2010-01-01

    Problem-based learning (PBL) is an instructional approach that is organized around the investigation and resolution of problems. Problems are neither uniform nor similar. Jonassen (1997, 2000) in his design theory of problem solving has categorized problems into two broad types--well-structured and ill-structured. He has also described a host of…

  12. Problem drinking's associations with social structure and mental health care: race/ethnicity differences.

    PubMed

    Lo, Celia C; Cheng, Tyrone C; Howell, Rebecca J

    2014-01-01

    This research used a nationally representative sample of 12,756 respondents self-identified as White, Black, Hispanic, or Asian to examine problem drinking in relationship to social structure and mental healthcare factors. Associations between problem drinking and particular factors varied by racial/ethnic group. Results also indicated that Whites' problem-drinking rates were higher than those of Hispanics, Blacks, and Asians. Americans sometimes use alcohol to manage stress stemming from social disadvantage and inadequate material resources. Across racial/ethnic groups, drinking level was associated with the type and degree of such disadvantage. Additionally, the presence of a mental health problem was associated with problem drinking.

  13. Using Problem-Based Case Studies to Learn about Knowledge Translation Interventions: An Inside Perspective

    ERIC Educational Resources Information Center

    Bhogal, Sanjit K.; Murray, Mary Ann; McLeod, Katherine M.; Bergen, Anne; Bath, Brenna; Menon, Anita; Kho, Michelle E.; Stacey, Dawn

    2011-01-01

    Knowledge translation (KT) interventions can facilitate the successful implementation of best practices by engaging and actively involving various stakeholders in the change process. However, for novices, the design of KT interventions can be overwhelming. In this article, we describe our experience as participants in a problem-based case study on…

  14. ESP Teaching at the Institutions of Higher Education in Modern Russia: Problems and Perspectives

    ERIC Educational Resources Information Center

    Prudnikova, Nadezhda

    2013-01-01

    The author analyses ESP teaching at the institutions of higher education in modern Russia, explains the main problems and suggests the ways of their solving, details the quality control system of the students' progress improvement, presents the complex approach to interactive ESP teaching and views it as an integral part of up-to-date…

  15. Operational problems with radiation survey meters - The University and Accelerator perspectives

    SciTech Connect

    McCall, R.C.

    1984-06-01

    This article describes problems encountered with commercial survey meters. The desired qualities of such instruments for use around accelerators are listed. Attempts to meet the accelerator monitoring needs by modifying commercial instruments and by in-house research and development are described.

  16. Multiple Imputation for Multivariate Missing-Data Problems: A Data Analyst's Perspective.

    ERIC Educational Resources Information Center

    Schafer, Joseph L.; Olsen, Maren K.

    1998-01-01

    The key ideas of multiple imputation for multivariate missing data problems are reviewed. Software programs available for this analysis are described, and their use is illustrated with data from the Adolescent Alcohol Prevention Trial (W. Hansen and J. Graham, 1991). (SLD)

  17. Facilitators' Perspectives of the Factors That Affect the Effectiveness of Problem-Based Learning Process

    ERIC Educational Resources Information Center

    Chan, Cecilia K. Y.

    2016-01-01

    Many educational researchers have established problem-based learning (PBL) as a total approach to education--both a product and a process--from a pedagogical instructional strategy to skills development to assessment. This study provides qualitative evidences from educational practitioners in various professional disciplines, namely, Medicine,…

  18. Environmental Education in an Urban Setting: Old Problems--New Perspectives.

    ERIC Educational Resources Information Center

    Cooper, R. Douglas; Smith, Bradley F.

    1989-01-01

    As North America increasingly becomes an urban society, questions surface as to the role and direction of environmental education programs. Such programs may hold potential in abating some of the problems inherent with contemporary inner city youth. Several successful on-going programs are reviewed. (Author/CW)

  19. A Modeling Perspective on the Teaching and Learning of Mathematical Problem Solving

    ERIC Educational Resources Information Center

    Mousoulides, Nicholas G.; Christou, Constantinos; Sriraman, Bharath

    2008-01-01

    This study analyzed the processes used by students when engaged in modeling activities and examined how students' abilities to solve modeling problems changed over time. Two student populations, one experimental and one control group, participated in the study. To examine students' modeling processes, the experimental group participated in an…

  20. [The current problems and cross-cultural perspectives of patient-doctor relation: an overview].

    PubMed

    Koch, Eckhardt; Turgut, Tolga

    2004-01-01

    The success of the treatment in medicine, especially in psychiatry is based on the form and the strength of the patient-doctor relation. This complex and dynamic relation is changing in accordance with the social and technological development of the society. The context of the patient-doctor relation is determined by the present day culture as well as the traditional background. An overview of current patient-doctor relation and of problems that physicians and in particular psychiatrists meet is presented. Physicians have responsibilities in building patient-doctor relation. The ethical and legal aspects of these responsibilities are presented. The former paternalistic type of patient-doctor relation is evolving into a more equal and democratic relation. New problems are being encountered continuously in the changing process. Beside the of the process itself, the effects of progress in medical technology and communication systems on patient-doctor relation and the pressure, put from the insurance companies and/or authorities on physicians, which impair the trust between the physician and his patient, are making the process more difficult. The issues of compliance, sexual harassment and unique problems of patient-doctor relations in psychiatry are the other subtopics in the article. The cross-cultural aspects of patient-doctor relations and encountered clinical problems are discussed with case examples particularly about Turkish immigrants, who live in Germany. Suggestions for psychiatrists in Germany to work out the challenges facing them are presented in the conclusion.

  1. Do Students Trust in Mathematics or Intuition during Physics Problem Solving? An Epistemic Game Perspective

    ERIC Educational Resources Information Center

    Yavuz, Ahmet

    2015-01-01

    This study aims to investigate (1) students' trust in mathematics calculation versus intuition in a physics problem solving and (2) whether this trust is related to achievement in physics in the context of epistemic game theoretical framework. To achieve this research objective, paper-pencil and interview sessions were conducted. A paper-pencil…

  2. Children's Comprehension Problems in Oral and Written Language: A Cognitive Perspective. Challenges in Language and Literacy

    ERIC Educational Resources Information Center

    Cain, Kate, Ed.; Oakhill, Jane, Ed.

    2007-01-01

    Comprehension is the ultimate aim of reading and listening. How do children develop the ability to comprehend written and spoken language, and what can be done to help those who are having difficulties? This book presents cutting-edge research on comprehension problems experienced by children without any formal diagnosis as well as those with…

  3. The Effects of Teaching Programming via Scratch on Problem Solving Skills: A Discussion from Learners' Perspective

    ERIC Educational Resources Information Center

    Kalelioglu, Filiz; Gülbahar, Yasemin

    2014-01-01

    Computer programming is perceived as an important competence for the development of problem solving skills in addition to logical reasoning. Hence, its integration throughout all educational levels, as well as the early ages, is considered valuable and research studies are carried out to explore the phenomenon in more detail. In light of these…

  4. Medical education and cognitive continuum theory: an alternative perspective on medical problem solving and clinical reasoning.

    PubMed

    Custers, Eugène J F M

    2013-08-01

    Recently, human reasoning, problem solving, and decision making have been viewed as products of two separate systems: "System 1," the unconscious, intuitive, or nonanalytic system, and "System 2," the conscious, analytic, or reflective system. This view has penetrated the medical education literature, yet the idea of two independent dichotomous cognitive systems is not entirely without problems.This article outlines the difficulties of this "two-system view" and presents an alternative, developed by K.R. Hammond and colleagues, called cognitive continuum theory (CCT). CCT is featured by three key assumptions. First, human reasoning, problem solving, and decision making can be arranged on a cognitive continuum, with pure intuition at one end, pure analysis at the other, and a large middle ground called "quasirationality." Second, the nature and requirements of the cognitive task, as perceived by the person performing the task, determine to a large extent whether a task will be approached more intuitively or more analytically. Third, for optimal task performance, this approach needs to match the cognitive properties and requirements of the task. Finally, the author makes a case that CCT is better able than a two-system view to describe medical problem solving and clinical reasoning and that it provides clear clues for how to organize training in clinical reasoning.

  5. Multiple Imputation for Multivariate Missing-Data Problems: A Data Analyst's Perspective.

    ERIC Educational Resources Information Center

    Schafer, Joseph L.; Olsen, Maren K.

    1998-01-01

    The key ideas of multiple imputation for multivariate missing data problems are reviewed. Software programs available for this analysis are described, and their use is illustrated with data from the Adolescent Alcohol Prevention Trial (W. Hansen and J. Graham, 1991). (SLD)

  6. Facilitators' Perspectives of the Factors That Affect the Effectiveness of Problem-Based Learning Process

    ERIC Educational Resources Information Center

    Chan, Cecilia K. Y.

    2016-01-01

    Many educational researchers have established problem-based learning (PBL) as a total approach to education--both a product and a process--from a pedagogical instructional strategy to skills development to assessment. This study provides qualitative evidences from educational practitioners in various professional disciplines, namely, Medicine,…

  7. Children's Comprehension Problems in Oral and Written Language: A Cognitive Perspective. Challenges in Language and Literacy

    ERIC Educational Resources Information Center

    Cain, Kate, Ed.; Oakhill, Jane, Ed.

    2007-01-01

    Comprehension is the ultimate aim of reading and listening. How do children develop the ability to comprehend written and spoken language, and what can be done to help those who are having difficulties? This book presents cutting-edge research on comprehension problems experienced by children without any formal diagnosis as well as those with…

  8. Age and Gender Differences in Coping Style across Various Problems: Omani Adolescents' Perspective

    ERIC Educational Resources Information Center

    Al-Bahrani, Muna; Aldhafri, Said; Alkharusi, Hussain; Kazem, Ali; Alzubiadi, Abdulqawi

    2013-01-01

    This study examines adolescents' coping styles, with relation to their gender and age and level, of six types of problems. The participants were 1843 adolescents (51.7% female and 48.3% male) from the Sultanate of Oman with a mean age of 15.75. Two scales examining general adaptive and maladaptive coping styles and levels of school, economic,…

  9. Students' Perspectives on Problem-Based Learning in a Transitional Doctorate of Physical Therapy Program

    ERIC Educational Resources Information Center

    Larin, Helene M.; Buccieri, Kathleen M.; Wessel, Jean

    2010-01-01

    Doctor of physical therapy (DPT) graduates are expected to be competent in professional behaviors, communication, critical inquiry, clinical decision making, and evidence-based practice. The purpose of this qualitative study was to describe the experience of students enrolled in a single, problem-based learning (PBL) course within a conventional…

  10. Do Students Trust in Mathematics or Intuition during Physics Problem Solving? An Epistemic Game Perspective

    ERIC Educational Resources Information Center

    Yavuz, Ahmet

    2015-01-01

    This study aims to investigate (1) students' trust in mathematics calculation versus intuition in a physics problem solving and (2) whether this trust is related to achievement in physics in the context of epistemic game theoretical framework. To achieve this research objective, paper-pencil and interview sessions were conducted. A paper-pencil…

  11. Molecular solutes in ionic liquids: a structural perspective.

    PubMed

    Pádua, Agílio A H; Costa Gomes, Margarida F; Canongia Lopes, José N A

    2007-11-01

    Understanding physicochemical properties of ionic liquids is important for their rational use in extractions, reactions, and other applications. Ionic liquids are not simple fluids: their ions are generally asymetric, flexible, with delocalized electrostatic charges, and available in a wide variety. It is difficult to capture their subtle properties with models that are too simplistic. Molecular simulation using atomistic force fields, which describe structures and interactions in detail, is an excellent tool to gain insights into their liquid-state organization, how they solvate different compounds, and what molecular factors determine their properties. The identification of certain ionic liquids as self-organized phases, with aggregated nonpolar and charged domains, provides a new way to interpret the solvation and structure of their mixtures. Many advances are the result of a successful interplay between experiment and modeling, possible in this field where none of the two methodologies had a previous advance.

  12. Evolutionary perspectives of telomerase RNA structure and function

    PubMed Central

    Podlevsky, Joshua D.; Chen, Julian J.-L.

    2016-01-01

    ABSTRACT Telomerase is the eukaryotic solution to the ‘end-replication problem’ of linear chromosomes by synthesising the highly repetitive DNA constituent of telomeres, the nucleoprotein cap that protects chromosome termini. Functioning as a ribonucleoprotein (RNP) enzyme, telomerase is minimally composed of the highly conserved catalytic telomerase reverse transcriptase (TERT) and essential telomerase RNA (TR) component. Beyond merely providing the template for telomeric DNA synthesis, TR is an innate telomerase component and directly facilitates enzymatic function. TR accomplishes this by having evolved structural elements for stable assembly with the TERT protein and the regulation of the telomerase catalytic cycle. Despite its prominence and prevalence, TR has profoundly diverged in length, sequence, and biogenesis pathway among distinct evolutionary lineages. This diversity has generated numerous structural and mechanistic solutions for ensuring proper RNP formation and high fidelity telomeric DNA synthesis. Telomerase provides unique insights into RNA and protein coevolution within RNP enzymes. PMID:27359343

  13. Buckling of structures with uncertain imperfections - Personal perspective

    NASA Technical Reports Server (NTRS)

    Elishakoff, Isaac

    1998-01-01

    The previous review on stochastic buckling of structures was written by Amazigo in 1976. This review summarizes some of the developments which took place in recent two decades. A brief overview is given of the effect on uncertainty in the initial geometric imperfections, elastic moduli, applied forces, and thickness variation. For the benefit of the thinking reader, the review has a critical nature. It should be noted that this manuscript has yet to be completed.

  14. Buckling of structures with uncertain imperfections - Personal perspective

    NASA Technical Reports Server (NTRS)

    Elishakoff, Isaac

    1998-01-01

    The previous review on stochastic buckling of structures was written by Amazigo in 1976. This review summarizes some of the developments which took place in recent two decades. A brief overview is given of the effect on uncertainty in the initial geometric imperfections, elastic moduli, applied forces, and thickness variation. For the benefit of the thinking reader, the review has a critical nature. It should be noted that this manuscript has yet to be completed.

  15. A Structural Perspective on the Dynamics of Kinesin Motors

    PubMed Central

    Hyeon, Changbong; Onuchic, José N.

    2011-01-01

    Despite significant fluctuation under thermal noise, biological machines in cells perform their tasks with exquisite precision. Using molecular simulation of a coarse-grained model and theoretical arguments, we envisaged how kinesin, a prototype of biological machines, generates force and regulates its dynamics to sustain persistent motor action. A structure-based model, which can be versatile in adapting its structure to external stresses while maintaining its native fold, was employed to account for several features of kinesin dynamics along the biochemical cycle. This analysis complements our current understandings of kinesin dynamics and connections to experiments. We propose a thermodynamic cycle for kinesin that emphasizes the mechanical and regulatory role of the neck linker and clarify issues related to the motor directionality, and the difference between the external stalling force and the internal tension responsible for the head-head coordination. The comparison between the thermodynamic cycle of kinesin and macroscopic heat engines highlights the importance of structural change as the source of work production in biomolecular machines. PMID:22261064

  16. A biomechanical perspective on stress fiber structure and function☆

    PubMed Central

    Kassianidou, Elena; Kumar, Sanjay

    2015-01-01

    Stress fibers are actomyosin-based bundles whose structural and contractile properties underlie numerous cellular processes including adhesion, motility and mechanosensing. Recent advances in high-resolution live-cell imaging and single-cell force measurement have dramatically sharpened our understanding of the assembly, connectivity, and evolution of various specialized stress fiber subpopulations. This in turn has motivated interest in understanding how individual stress fibers generate tension and support cellular structure and force generation. In this review, we discuss approaches for measuring the mechanical properties of single stress fibers. We begin by discussing studies conducted in cell-free settings, including strategies based on isolation of intact stress fibers and reconstitution of stress fiber-like structures from purified components. We then discuss measurements obtained in living cells based both on inference of stress fiber properties from whole-cell mechanical measurements (e.g., atomic force microscopy) and on direct interrogation of single stress fibers (e.g., subcellular laser nanosurgery). We conclude by reviewing various mathematical models of stress fiber function that have been developed based on these experimental measurements. An important future challenge in this area will be the integration of these sophisticated biophysical measurements with the field’s increasingly detailed molecular understanding of stress fiber assembly, dynamics, and signal transduction. This article is part of a Special Issue entitled: Mechanobiology. PMID:25896524

  17. Technological Change and Social Progress: Some Problems and Perspectives. Report of the Director-General No. I.

    ERIC Educational Resources Information Center

    International Labour Office, Geneva (Switzerland).

    This report examines economic and social developments in Europe since 1950 in terms of structural change, productivity, economic integration and planning, regional development, and human problems and social policy-making. Evolving policies concerning income levels and distribution, conditions of work and life, and labor relations in Europe are…

  18. Some New Problems on Shells and Thin Structures

    NASA Technical Reports Server (NTRS)

    Vlasov, V. S.

    1949-01-01

    Cylindrical shells of arbitrary section, reinforced by longitudinal and transverse members (stringers and ribs) are considered by us, for a sufficiently close spacing of the ribs, as in our previously published papers (references 1 end 2), as thin-walled orthotropic spatial systems at the cross-sections of which only axial (normal and shearing) forces can arise. The longitudinal bending and twisting moments, due to their weak effect on the stress state of the shell, are taken equal to zero. Along the longitudinal sections of the shell there may arise transverse forces in addition to the normal d shearing forces. Under the so-called static assumptions there is taken for the computation model of the shell a thin-walled spatial system consisting along its length (along a generator) of an infinite number of elementary strips capable of bending. Each of these strips is likened to a curved rod operating in each of its sections not only in tension (compression)but also in transverse bending and shear. The interaction between two adjoining transverse strips in the shell expresses itself in the transmission from one strip to the other of only the normal and shearing stresses. The static structure of the computation model here described is shown in figure 1, where the connections through which the normal and shearing stresses transmitted from one transverse strip to smother are indicated schematically by the rods located in the middle surface of the shell. In addition to the static hypothesis we introduce also geometric hypotheses. According to the latter the elongational deformations of the shell along lines parallel to the generator of its middle surface and the shear deformations in the middle surface, as ma+gitudes having . little effect on the state of the fundamental internal forces of the shell, are taken equal to zero. The deformations of the shell in our computational model are such that in the first place the lines of this surface perpendicular to the generator are

  19. Structure preserving parallel algorithms for solving the Bethe–Salpeter eigenvalue problem

    DOE PAGES

    Shao, Meiyue; da Jornada, Felipe H.; Yang, Chao; ...

    2015-10-02

    The Bethe–Salpeter eigenvalue problem is a dense structured eigenvalue problem arising from discretized Bethe–Salpeter equation in the context of computing exciton energies and states. A computational challenge is that at least half of the eigenvalues and the associated eigenvectors are desired in practice. In this paper, we establish the equivalence between Bethe–Salpeter eigenvalue problems and real Hamiltonian eigenvalue problems. Based on theoretical analysis, structure preserving algorithms for a class of Bethe–Salpeter eigenvalue problems are proposed. We also show that for this class of problems all eigenvalues obtained from the Tamm–Dancoff approximation are overestimated. In order to solve large scale problemsmore » of practical interest, we discuss parallel implementations of our algorithms targeting distributed memory systems. Finally, several numerical examples are presented to demonstrate the efficiency and accuracy of our algorithms.« less

  20. "Talk with me": perspectives on services for men with problem gambling and housing instability.

    PubMed

    Guilcher, Sara J T; Hamilton-Wright, Sarah; Skinner, Wayne; Woodhall-Melnik, Julia; Ferentzy, Peter; Wendaferew, Aklilu; Hwang, Stephen W; Matheson, Flora I

    2016-08-02

    Problem gambling and homelessness are recognized as important public health concerns that significantly impact individuals, their friends and families, communities and broader society. We aimed to explore the experiences with health and social services of men who had histories of problem gambling and housing instability in Toronto, Ontario. We used a community-based participatory approach with a multi-service agency serving low-income individuals. We conducted qualitative interviews with men (n = 30) who had experienced problem gambling and housing instability. Our interviews employed open-ended questions to elicit men's perceptions of services related to housing instability, problem gambling and other comorbid conditions (e.g., mental illness, substance use). We reviewed relevant themes related to experiences with services (e.g., Use of and feedback on: health and social services, housing services, justice/legal aid services, substance use services, gambling services; stigma; goals; triggers; physical health; coping strategies; finances; relationships; barriers to services and recommendations for services). The concept of person-centred engagement was identified as a main overarching theme, and seemed to be lacking in most of the men's experiences of services. Person-centred engagement for these men entailed empowerment and autonomy; empathy, compassion and sincerity; respectful communication; and tailored and holistic life plans. While there was a strong emphasis placed on independence, the men identified the importance of positive therapeutic relationships as being critical aspects of the recovery process. Based on our analyses, several recommendations were identified: 1) Increasing general awareness of services for problem gambling; 2) Delivering integrated services in a one-stop-shop; 3) Addressing mental health with psychotherapy and pharmacotherapy; 4) Providing timely access to prevention and recovery services; and 5) Enhancing life skills with peer

  1. Pilins in gram-positive bacteria: A structural perspective.

    PubMed

    Krishnan, Vengadesan

    2015-07-01

    Pilins or fimbrilins are a class of proteins found in bacterial surface pilus, a hair-like surface appendage. Both the Gram-negative and -positive bacteria produce pilins to assemble pili on their cell-surface for different purposes including adherence, twitching motility, conjugation, immunomodulation, biofilm formation, and electron transfer. Immunogenic properties of the pilins make them attractive vaccine candidates. The polymerized pilins play a key role in the initiation of host adhesion, which is a critical step for bacterial colonization and infection. Because of their key role in adhesion and exposure on the cell surface, targeting the pilins-mediated adhesion (anti-adhesion therapy) is also seen as a promising alternative approach for preventing and treating bacterial infections, one that may overcome their ever-increasing repertoires of resistance mechanisms. Individual pilins interact with each other non-covalently to assemble the pilus fiber with the help of associated proteins like chaperones and Usher in Gram-negative bacteria. In contrast, the pilins in Gram-positive bacteria often connect with each other covalently, with the help of sortases. Certain unique structural features present on the pilins distinguish them from one another across different bacterial strains, and these dictate their cellular targets and functions. While the structure of pilins has been extensively studied in Gram-negative pathogenic bacteria, the pilins in Gram-positive pathogenic bacteria have been in only during the last decade. Recently, the discovery of pilins in non-pathogenic bacteria, such as Lactobacillus rhamnosus GG, has received great attention, though traditionally the attention was on pathogenic bacteria. This review summarizes and discusses the current structural knowledge of pilins in Gram-positive bacteria with emphasis on those pilins which are sortase substrates.

  2. Structure, function and evolution of the gas exchangers: comparative perspectives.

    PubMed

    Maina, J N

    2002-10-01

    Over the evolutionary continuum, animals have faced similar fundamental challenges of acquiring molecular oxygen for aerobic metabolism. Under limitations and constraints imposed by factors such as phylogeny, behaviour, body size and environment, they have responded differently in founding optimal respiratory structures. A quintessence of the aphorism that 'necessity is the mother of invention', gas exchangers have been inaugurated through stiff cost-benefit analyses that have evoked transaction of trade-offs and compromises. Cogent structural-functional correlations occur in constructions of gas exchangers: within and between taxa, morphological complexity and respiratory efficiency increase with metabolic capacities and oxygen needs. Highly active, small endotherms have relatively better-refined gas exchangers compared with large, inactive ectotherms. Respiratory structures have developed from the plain cell membrane of the primeval prokaryotic unicells to complex multifunctional ones of the modern Metazoa. Regarding the respiratory medium used to extract oxygen from, animal life has had only two choices--water or air--within the biological range of temperature and pressure the only naturally occurring respirable fluids. In rarer cases, certain animals have adapted to using both media. Gills (evaginated gas exchangers) are the primordial respiratory organs: they are the archetypal water breathing organs. Lungs (invaginated gas exchangers) are the model air breathing organs. Bimodal (transitional) breathers occupy the water-air interface. Presentation and exposure of external (water/air) and internal (haemolymph/blood) respiratory media, features determined by geometric arrangement of the conduits, are important features for gas exchange efficiency: counter-current, cross-current, uniform pool and infinite pool designs have variably developed.

  3. Corynebacterium diphtheriae: genome diversity, population structure and genotyping perspectives.

    PubMed

    Mokrousov, Igor

    2009-01-01

    The epidemic re-emergence of diphtheria in Russia and the Newly Independent States (NIS) of the former Soviet Union in the 1990s demonstrated the continued threat of this thought to be rare disease. The bacteriophage encoded toxin is a main virulence factor of Corynebacterium diphtheriae, however, an analysis of the first complete genome sequence of C. diphtheriae revealed a recent acquisition of other pathogenicity factors including iron-uptake systems, adhesins and fimbrial proteins as indeed this extracellular pathogen has more possibilities for lateral gene transfer than, e.g., its close relative, mainly intracellular Mycobacterium tuberculosis. C. diphtheriae appears to have a phylogeographical structure mainly represented by area-specific variants whose circulation is under strong influence of human host factors, including health control measures, first of all, vaccination, and social economic conditions. This framework core population structure may be challenged by importation of the endemic and eventually toxigenic strains from new areas thus leading to localized or large epidemics caused directly by imported strains or by bacteriophage-lysogenized indigenous strains converted into toxin production. A feature of C. diphtheriae co-existence with humans is its periodicity: following large epidemic in the 1990s, the present period is marked by increasing heterogeneity of the circulating populations whereas re-emergence of new toxigenic variants along with persistent circulation of invasive non-toxigenic strains appear alarming. To identify and rapidly monitor subtle changes in the genome structure at an infraclonal level during and between epidemics, portable and discriminatory typing methods of C. diphtheriae are still needed. In this view, CRISPRs and minisatellites are promising genomic markers for development of high-resolution typing schemes and databasing of C. diphtheriae.

  4. Family caregiving in dementia: the Asian perspective of a global problem.

    PubMed

    Chan, Sally Wai-Chi

    2010-01-01

    With an increasing life expectancy, the number of people suffering from dementia globally will rise to about 115.4 million by 2050. It is projected that in the 21st century, the majority of the world's older people will be living in Asia. This paper examines the global issues of family caregiving for older persons with dementia from an Asian perspective. Literature review of published empirical studies from 1990 to October 2010. A full understanding of the specific way that culture could influence family caregivers' burdens may play an important part in the development of a holistic model for family-centered care. Well-designed psychoeducation interventions or multicomponent interventions could help in reducing caregivers' burden. With socio-economical and demographical changes, families need to be supported when taking on the caregiving role and be offered alternatives of care. There is a need for future trials with more rigorous randomization and longitudinal follow-up to assess family caregiver burdens at different illness stages. Future studies could focus on protective factors that promote caregivers' resilience. It is essential to develop psychometrically robust measures for family caregiver burden and gain. Copyright © 2011 S. Karger AG, Basel.

  5. Perspective: Closing the Dietary Fiber Gap: An Ancient Solution for a 21st Century Problem.

    PubMed

    Thompson, Henry J; Brick, Mark A

    2016-07-01

    An important gap exists between the daily amounts of fiber recommended in the human diet (28-42 g/d) and that which is actually consumed (median intake, 12-14 g/d). In fact, <5% of Americans meet the recommended intake for dietary fiber, and the magnitude of the gap is large, approximately a 50-70% shortfall. Because considerable evidence indicates that dietary fiber affects normal physiologic function and the onset of chronic diseases and their progression, the fiber gap represents an opportune target at which dietary interventions can be directed. This perspective considers whether a scientific basis exists for the current lack of emphasis on pulse crops, that is, grain legumes (common bean, chickpea, lentils, and garden pea) as a concentrated, inexpensive, and widely available source of dietary fiber. Attention is directed to this topic because the fiber gap has existed for decades with little improvement despite nutrition labeling, consumer education about the value of whole-grain cereal crop-based products, and the introduction of many fiber-enriched foods. The time is long overdue to identify additional approaches that have the potential to close the dietary fiber gap. To this end, the potential role of pulse crops in remediating this gap is examined. © 2016 American Society for Nutrition.

  6. Perspective: Closing the Dietary Fiber Gap: An Ancient Solution for a 21st Century Problem12

    PubMed Central

    Thompson, Henry J; Brick, Mark A

    2016-01-01

    An important gap exists between the daily amounts of fiber recommended in the human diet (28–42 g/d) and that which is actually consumed (median intake, 12–14 g/d). In fact, <5% of Americans meet the recommended intake for dietary fiber, and the magnitude of the gap is large, approximately a 50–70% shortfall. Because considerable evidence indicates that dietary fiber affects normal physiologic function and the onset of chronic diseases and their progression, the fiber gap represents an opportune target at which dietary interventions can be directed. This perspective considers whether a scientific basis exists for the current lack of emphasis on pulse crops, that is, grain legumes (common bean, chickpea, lentils, and garden pea) as a concentrated, inexpensive, and widely available source of dietary fiber. Attention is directed to this topic because the fiber gap has existed for decades with little improvement despite nutrition labeling, consumer education about the value of whole-grain cereal crop-based products, and the introduction of many fiber-enriched foods. The time is long overdue to identify additional approaches that have the potential to close the dietary fiber gap. To this end, the potential role of pulse crops in remediating this gap is examined. PMID:27422499

  7. Predicting the future from the past: An old problem from a modern perspective

    NASA Astrophysics Data System (ADS)

    Cecconi, F.; Cencini, M.; Falcioni, M.; Vulpiani, A.

    2012-11-01

    The idea of predicting the future from the knowledge of the past is quite natural, even when dealing with systems whose equations of motion are not known. This long-standing issue is revisited in the light of modern ergodic theory of dynamical systems and becomes particularly interesting from a pedagogical perspective due to its close link with Poincaré's recurrence. Using such a connection, a very general result of ergodic theory—Kac's lemma—can be used to establish the intrinsic limitations to the possibility of predicting the future from the past. In spite of a naive expectation, predictability is hindered more by the effective number of degrees of freedom of a system than by the presence of chaos. If the effective number of degrees of freedom becomes large enough, whether the system is chaotic or not, predictions turn out to be practically impossible. The discussion of these issues is illustrated with the help of the numerical study of simple models.

  8. [Volunteering in end-of-life care : Challenges, problems and perspectives].

    PubMed

    Schneider, Werner

    2017-01-01

    Volunteering in the hospice movement has had a profound impact on generating awareness of hospice work and palliative care in the context of supporting dying persons and their relatives as well as on integrating respective services in the existing health care system. This paper focuses on two specific questions: First, it asks how society is changing with respect to dealing with dying and death, and more precisely with dying persons, which is recognizable by the integration of hospice work and palliative care in the healthcare system and related to the relevance of volunteering in the sense of a citizens' movement. Second, this paper asks what the specific roles of volunteers are as well as the possibilities and limits of voluntary practice in end-of-life care and accompaniment. To answer these questions, the pivotal objectives of the hospice movement - the transformation of the social awareness regarding dying and death, as well as the reorganization of "institutions of dying" - will first be outlined by reference to the concept of "good dying", a specific hospice attitude together with hospice culture and palliative competence. In a second step, the relevance of volunteering and the specific role of volunteers in the actual practice of hospice work and palliative care will be outlined alongside current indicators and recognizable alteration tendencies, before concluding with a discussion of the perspectives of hospices as a citizens' movement.

  9. Strengths and weaknesses of Problem Based Learning from the professional perspective of registered nurses 1

    PubMed Central

    Cónsul-Giribet, María; Medina-Moya, José Luis

    2014-01-01

    OBJECTIVE: to identify competency strengths and weaknesses as perceived by nursing professionals who graduated with a integrated curriculum and competency-based through Problem Based Learning in small groups. METHOD: an intrinsic case study method was used, which analyzes this innovation through former students (from the first class) with three years of professional experience. The data were collected through a questionnaire and discussion groups. RESULTS: the results show that their competency level is valued in a very satisfactory manner. This level paradoxically contrasts with the lack of theoretical knowledge they perceived at the end of their education, when they started working in clinical practice. CONCLUSIONS: the teaching strategy was key to motivate an in-depth study and arouse the desire to know. In addition, Problem Based Learning favors and reinforces the decision to learn, which is that necessary in the course of professional life. PMID:25493666

  10. An Existential Perspective on Death Anxiety, Retirement, and Related Research Problems.

    PubMed

    Osborne, John W

    2017-06-01

    Aspects of existentialism relevant to existence and death anxiety (DA) are discussed. Included are the "thrownness" of existence, being-with-others, the motivational influence of inevitable death, the search for meaning, making the most of existence by taking responsibility for one's own life, and coping with existential isolation. The attempted separation of DA from object anxiety is a significant difficulty. The correlations among age, gender, and DA are variable. Personality and role-oriented problems in the transition to retirement are discussed along with Erikson's notion of "generativity" as an expression of the energy and purpose of mid-life. Furthermore, methodological and linguistic problems in DA research are considered. The article suggests qualitative methodologies as an interpersonal means of exploring DA within the contexts of psychotherapy and counselling.

  11. Strengths and weaknesses of Problem Based Learning from the professional perspective of registered nurses.

    PubMed

    Cónsul-Giribet, María; Medina-Moya, José Luis

    2014-10-01

    To identify competency strengths and weaknesses as perceived by nursing professionals who graduated with a integrated curriculum and competency-based through Problem Based Learning in small groups. An intrinsic case study method was used, which analyzes this innovation through former students (from the first class) with three years of professional experience. The data were collected through a questionnaire and discussion groups. The results show that their competency level is valued in a very satisfactory manner. This level paradoxically contrasts with the lack of theoretical knowledge they perceived at the end of their education, when they started working in clinical practice. The teaching strategy was key to motivate an in-depth study and arouse the desire to know. In addition, Problem Based Learning favors and reinforces the decision to learn, which is that necessary in the course of professional life.

  12. Upper error bounds on calculated outputs of interest for linear and nonlinear structural problems

    NASA Astrophysics Data System (ADS)

    Ladevèze, Pierre

    2006-07-01

    This Note introduces new strict upper error bounds on outputs of interest for linear as well as time-dependent nonlinear structural problems calculated by the finite element method. Small-displacement problems without softening, such as (visco)plasticity problems, are included through the standard thermodynamics framework involving internal state variables. To cite this article: P. Ladevèze, C. R. Mecanique 334 (2006).

  13. Structuring Process Skills and the Solution of Verbal Problems Involving Science Concepts.

    ERIC Educational Resources Information Center

    Champagne, Audrey B.; Klopfer, Leopold E.

    1981-01-01

    Investigates the interaction between semantic knowledge and process skills in eighth-grade students' (N=27) performance in solving two types of problems (analogies and set-membership) of inducing structure drawn from physical geology concepts. (DS)

  14. Solving the Phase Problem in Crystal Structure Determination: A Simple Introduction to Direct Methods.

    ERIC Educational Resources Information Center

    Schenk, H.

    1979-01-01

    Presents a simple way to introduce Direct Methods program systems to solve phase problems in x-ray crystal structure determination. It is intended for the undergraduate chemistry student laboratory. (Author/SA)

  15. Anti-cancer chalcones: Structural and molecular target perspectives.

    PubMed

    Mahapatra, Debarshi Kar; Bharti, Sanjay Kumar; Asati, Vivek

    2015-06-15

    Chalcone or (E)-1,3-diphenyl-2-propene-1-one scaffold remained a fascination among researchers in the 21st century due to its simple chemistry, ease of synthesis and a wide variety of promising biological activities. Several natural and (semi) synthetic chalcones have shown anti-cancer activity due to their inhibitory potential against various targets namely ABCG2/P-gp/BCRP, 5α-reductase, aromatase, 17-β-hydroxysteroid dehydrogenase, HDAC/Situin-1, proteasome, VEGF, VEGFR-2 kinase, MMP-2/9, JAK/STAT signaling pathways, CDC25B, tubulin, cathepsin-K, topoisomerase-II, Wnt, NF-κB, B-Raf and mTOR etc. In this review, a comprehensive study on molecular targets/pathways involved in carcinogenesis, mechanism of actions (MOAs), structure activity relationships (SARs) and patents granted have been highlighted. With the knowledge of molecular targets, structural insights and SARs, this review may be helpful for (medicinal) chemists to design more potent, safe, selective and cost effective anti-cancer chalcones.

  16. Perspectives of pupils, parents, and teachers on mental health problems among Vietnamese secondary school pupils

    PubMed Central

    2013-01-01

    Background Secondary school can be a stressful period for adolescents, having to cope with many life changes. Very little research has been conducted on the mental health status of secondary school pupils in South East Asian countries, such as Vietnam. The study aimed to explore perceptions of mental health status, risk factors for mental health problems and strategies to improve mental health among Vietnamese secondary school students. Methods A qualitative design was used to address the main study question including: six in-depth interviews conducted with professionals (with two researchers, two psychiatrists, and two secondary school teachers) to learn about their experience of mental health problems among secondary school pupils; 13 focus group discussions (four with teachers, four with parents, and five with pupils); and 10 individual in-depth interviews with pupils who did not take part in the FGDs, to reflect on the collected data and to deepen the authors’ understanding. All interviews and FGDs were audio-taped, transcribed and analyzed for the identification of emerging issues using qualitative techniques of progressive coding, analytic memoing and ongoing comparison. Results Our study confirms the need to pay attention to mental health of pupils in Vietnam. Depression, anxiety, stress, suicidal thoughts and suicide attempts were seen as major problems by all stakeholders. Mental health problems were mainly associated with academic pressure, resulting from an overloaded curriculum and pressure from teachers and parents to succeed. The study found that pupils’ mental health demands interventions at many levels, including at the level of government (Ministry of Education and Training), schools, communities, families and pupils themselves. Conclusions Vietnamese secondary school pupils feel that their mental health status is poor, because of many risk factors in their learning and living environment. The need now is to investigate further to identify and

  17. Screening for alcohol problems: an epidemiological perspective and implications for primary care.

    PubMed

    Grucza, Richard A; Przybeck, Thomas R; Cloninger, C Robert

    2008-01-01

    In a random sample of 917 adults from the general population greater St. Louis, 19.6% of respondents screened positive for "probable alcohol abuse or dependence". Screening positive is indicative of unhealthy drinking patterns. The regular use of such instruments in primary care settings could facilitate patient-physician communication regarding alcohol problems, thereby improving detection and leading to greater utilization of appropriate medical treatment, including pharmacotherapy.

  18. Cognitive conflict as a teaching strategy in solving chemistry problems: A dialectic-constructivist perspective

    NASA Astrophysics Data System (ADS)

    Niaz, Mansoor

    The main objective of this study was to evaluate the effect of teaching experiments within a dialectic-constructivist framework based on the following considerations: (a) Cognitive conflicts used in the teaching experiments must be based on problem-solving strategies that students find relatively convincing: (b) after having generated a cognitive conflict, it is essential that the students be provided with an experience that could facilitate the resolution of the conflict; and (c) the teaching strategy developed is used by an interactive constructivist approach within an intact classroom. The study was based on two sections of freshman students who had registered for Chemistry I at the Universidad de Oriente, Venezuela. One of the sections was randomly designated as the control group and the other as the experimental group. To introduce cognitive conflict, the experimental group was exposed to two teaching experiments dealing with stoichiometry problems based on the concept of limiting reagent. Students in the control group were exposed to the same problems - however, without the cognitive conflict teaching experiments format. To evaluate the effect of the teaching experiments, both groups were evaluated on five different problems at different intervals during the semester, referred to as posttests. All posttests formed part of the regular evaluation of the students. Results obtained show the advantage of the experimental group on four of the posttests. It is concluded that the experimental treatment was effective in improving performance on the immediate posttests. It was observed that some students protect their core belief [see Lakatos, I. (1970). Falsification and the methodology of scientific research programmes. In I. Lakatos & A. Musgrave (Eds.), Criticism and the growth of knowledge (pp. 91-196). Cambridge: Cambridge University Press] in stoichiometry (establishing equivalent relations between different elements or compounds) by ignoring the conflicting

  19. Individual differences in perspective taking and field-independence mediate structural persistence in dialog.

    PubMed

    Horton, William S

    2014-07-01

    Speakers often reuse syntactic constructions recently produced by an interlocutor. As a form of conversational repetition, evidence for such structural persistence may depend on the extent to which different people are sensitive to the linguistic contributions of others. To investigate how individual differences might mediate the likelihood of structural persistence in dialog, two potential measures of such sensitivity - a measure of self-reported perspective taking and a measure of field-dependence/independence - were collected from participants who also worked with a confederate partner on a picture description task adopted from Branigan, Pickering, and Cleland (2000). Following prime descriptions produced by the confederate, participants produced target descriptions of ditransitive events that could be described with either prepositional dative (PD) or double object (DO) constructions. In general, participants who rated themselves higher in perspective taking and who were identified as more field-independent showed more evidence of repeating the partner's syntax; however, these patterns were limited to PD primes. Variability in sensitivity to others' perspectives, and variability in one's ability to attend to local structure, may shape the likelihood that interlocutors will display evidence for structural persistence in dialog. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Structure-property relationships of multiferroic materials: A nano perspective

    NASA Astrophysics Data System (ADS)

    Bai, Feiming

    The integration of sensors, actuators, and control systems is an ongoing process in a wide range of applications covering automotive, medical, military, and consumer electronic markets. Four major families of ceramic and metallic actuators are under development: piezoelectrics, electrostrictors, magnetostrictors, and shape-memory alloys. All of these materials undergo at least two phase transformations with coupled thermodynamic order parameters. These transformations lead to complex domain wall behaviors, which are driven by electric fields (ferroelectrics), magnetic fields (ferromagnetics), or mechanical stress (ferroelastics) as they transform from nonferroic to ferroic states, contributing to the sensing and actuating capabilities. This research focuses on two multiferroic crystals, Pb(Mg1/3Nb 2/3)O3-PbTiO3 and Fe-Ga, which are characterized by the co-existence and coupling of ferroelectric polarization and ferroelastic strain, or ferro-magnetization and ferroelastic strain. These materials break the conventional boundary between piezoelectric and electrostrictors, or magnetostrictors and shape-memory alloys. Upon applying field or in a poled condition, they yield not only a large strain but also a large strain over field ratio, which is desired and much benefits for advanced actuator and sensor applications. In this thesis, particular attention has been given to understand the structure-property relationships of these two types of materials from atomic to the nano/macro scale. X-ray and neutron diffraction were used to obtain the lattice structure and phase transformation characteristics. Piezoresponse and magnetic force microscopy were performed to establish the dependence of domain configurations on composition, thermal history and applied fields. It has been found that polar nano regions (PNRs) make significant contributions to the enhanced electromechanical properties of PMN-x%PT crystals via assisting intermediate phase transformation. With increasing PT

  1. The Effect of Visual Representation Style in Problem-Solving: A Perspective from Cognitive Processes

    PubMed Central

    Nyamsuren, Enkhbold; Taatgen, Niels A.

    2013-01-01

    Using results from a controlled experiment and simulations based on cognitive models, we show that visual presentation style can have a significant impact on performance in a complex problem-solving task. We compared subject performances in two isomorphic, but visually different, tasks based on a card game of SET. Although subjects used the same strategy in both tasks, the difference in presentation style resulted in radically different reaction times and significant deviations in scanpath patterns in the two tasks. Results from our study indicate that low-level subconscious visual processes, such as differential acuity in peripheral vision and low-level iconic memory, can have indirect, but significant effects on decision making during a problem-solving task. We have developed two ACT-R models that employ the same basic strategy but deal with different presentations styles. Our ACT-R models confirm that changes in low-level visual processes triggered by changes in presentation style can propagate to higher-level cognitive processes. Such a domino effect can significantly affect reaction times and eye movements, without affecting the overall strategy of problem solving. PMID:24260415

  2. The effect of visual representation style in problem-solving: a perspective from cognitive processes.

    PubMed

    Nyamsuren, Enkhbold; Taatgen, Niels A

    2013-01-01

    Using results from a controlled experiment and simulations based on cognitive models, we show that visual presentation style can have a significant impact on performance in a complex problem-solving task. We compared subject performances in two isomorphic, but visually different, tasks based on a card game of SET. Although subjects used the same strategy in both tasks, the difference in presentation style resulted in radically different reaction times and significant deviations in scanpath patterns in the two tasks. Results from our study indicate that low-level subconscious visual processes, such as differential acuity in peripheral vision and low-level iconic memory, can have indirect, but significant effects on decision making during a problem-solving task. We have developed two ACT-R models that employ the same basic strategy but deal with different presentations styles. Our ACT-R models confirm that changes in low-level visual processes triggered by changes in presentation style can propagate to higher-level cognitive processes. Such a domino effect can significantly affect reaction times and eye movements, without affecting the overall strategy of problem solving.

  3. Perceptual Learning in Early Mathematics: Interacting with Problem Structure Improves Mapping, Solving and Fluency

    ERIC Educational Resources Information Center

    Thai, Khanh-Phuong; Son, Ji Y.; Hoffman, Jessica; Devers, Christopher; Kellman, Philip J.

    2014-01-01

    Mathematics is the study of structure but students think of math as solving problems according to rules. Students can learn procedures, but they often have trouble knowing when to apply learned procedures, especially to problems unlike those they trained with. In this study, the authors rely on the psychological mechanism of perceptual learning…

  4. Structured Parenting of Toddlers at High versus Low Genetic Risk: Two Pathways to Child Problems

    ERIC Educational Resources Information Center

    Leve, Leslie D.; Harold, Gordon T.; Ge, Xiaojia; Neiderhiser, Jenae M.; Shaw, Daniel; Scaramella, Laura V.; Reiss, David

    2009-01-01

    Objective: Little is known about how parenting might offset genetic risk to prevent the onset of child problems during toddlerhood. We used a prospective adoption design to separate genetic and environmental influences and test whether associations between structured parenting and toddler behavior problems were conditioned by genetic risk for…

  5. Percentages: The Effect of Problem Structure, Number Complexity and Calculation Format

    ERIC Educational Resources Information Center

    Baratta, Wendy; Price, Beth; Stacey, Kaye; Steinle, Vicki; Gvozdenko, Eugene

    2010-01-01

    This study reports how the difficulty of simple worded percentage problems is affected by the problem structure and the complexity of the numbers involved. We also investigate which methods students know. Results from 677 Year 8 and 9 students are reported. Overall the results indicate that more attention needs to be given to this important topic.…

  6. How Instructional Design Experts Use Knowledge and Experience to Solve Ill-Structured Problems

    ERIC Educational Resources Information Center

    Ertmer, Peggy A.; Stepich, Donald A.; York, Cindy S.; Stickman, Ann; Wu, Xuemei (Lily); Zurek, Stacey; Goktas, Yuksel

    2008-01-01

    This study examined how instructional design (ID) experts used their prior knowledge and previous experiences to solve an ill-structured instructional design problem. Seven experienced designers used a think-aloud procedure to articulate their problem-solving processes while reading a case narrative. Results, presented in the form of four…

  7. Supervisors' Structuring and Consideration Behaviors and Workers' Job Satisfaction, Stress, and Health Problems.

    ERIC Educational Resources Information Center

    Stout, John K.

    1984-01-01

    Focused on the relationship between supervisors' structuring (task orientation) and consideration (relationship orientation) behaviors and job satisfation, stress, and health problems of 78 rehabilitation workers. Higher job satisfaction and lower stress were related to high supervisor consideration. More health problems were reported when…

  8. NearTree, a data structure and a software toolkit for the nearest-neighbor problem

    PubMed Central

    Andrews, Lawrence C.; Bernstein, Herbert J.

    2016-01-01

    Many problems in crystallography and other fields can be treated as nearest-neighbor problems. The neartree data structure provides a flexible way to organize and retrieve metric data. In some cases, it can provide near-optimal performance. NearTree is a software tool that constructs neartrees and provides a number of different query tools. PMID:27275134

  9. Evidence of Second-Order Factor Structure in a Diagnostic Problem Space: Implications for Medical Education.

    ERIC Educational Resources Information Center

    Papa, Frank J.; And Others

    1997-01-01

    Chest pain was identified as a specific medical problem space, and disease classes were modeled to define it. Results from a test taken by 628 medical residents indicate a second-order factor structure that suggests that chest pain is a multidimensional problem space. Implications for medical education are discussed. (SLD)

  10. The Structure and Stability of Externalizing and Internalizing Problem Behavior during Early Adolescence

    ERIC Educational Resources Information Center

    Reitz, E.; Dekovic, M.; Meijer, A. M.

    2005-01-01

    The first aim of this study was to examine the structure of externalizing and internalizing problem behavior during early adolescence. Our second aim was to determine the stability of these problems for boys and for girls over time. A total of 650, 13-14-year-olds filled out (an expanded version of) the Youth Self-Report [YSR; "Manual for the…

  11. Structured Parenting of Toddlers at High versus Low Genetic Risk: Two Pathways to Child Problems

    ERIC Educational Resources Information Center

    Leve, Leslie D.; Harold, Gordon T.; Ge, Xiaojia; Neiderhiser, Jenae M.; Shaw, Daniel; Scaramella, Laura V.; Reiss, David

    2009-01-01

    Objective: Little is known about how parenting might offset genetic risk to prevent the onset of child problems during toddlerhood. We used a prospective adoption design to separate genetic and environmental influences and test whether associations between structured parenting and toddler behavior problems were conditioned by genetic risk for…

  12. Structured parenting of toddlers at high versus low genetic risk: two pathways to child problems.

    PubMed

    Leve, Leslie D; Harold, Gordon T; Ge, Xiaojia; Neiderhiser, Jenae M; Shaw, Daniel; Scaramella, Laura V; Reiss, David

    2009-11-01

    Little is known about how parenting might offset genetic risk to prevent the onset of child problems during toddlerhood. We used a prospective adoption design to separate genetic and environmental influences and test whether associations between structured parenting and toddler behavior problems were conditioned by genetic risk for psychopathology. The sample included 290 linked sets of adoptive families and birth mothers and 95 linked birth fathers. Genetic risk was assessed via birth mother and birth father psychopathology (anxiety, depression, antisociality, and drug use). Structured parenting was assessed via microsocial coding of adoptive mothers' behavior during a cleanup task. Toddler behavior problems were assessed with the Child Behavior Checklist. Controlling for temperamental risk at 9 months, there was an interaction between birth mother psychopathology and adoptive mothers' parenting on toddler behavior problems at 18 months. The interaction indicated two pathways to child problems: structured parenting was beneficial for toddlers at high genetic risk but was related to behavior problems for toddlers at low genetic risk. This crossover interaction pattern was replicated with birth father psychopathology as the index of genetic risk. The effects of structured parenting on toddler behavior problems varied as a function of genetic risk. Children at genetic risk might benefit from parenting interventions during toddlerhood that enhance structured parenting.

  13. Ran-dependent nuclear export mediators: a structural perspective.

    PubMed

    Güttler, Thomas; Görlich, Dirk

    2011-08-31

    Nuclear export is an essential eukaryotic activity. It proceeds through nuclear pore complexes (NPCs) and is mediated by soluble receptors that shuttle between nucleus and cytoplasm. RanGTPase-dependent export mediators (exportins) constitute the largest class of these carriers and are functionally highly versatile. All of these exportins load their substrates in response to RanGTP binding in the nucleus and traverse NPCs as ternary RanGTP-exportin-cargo complexes to the cytoplasm, where GTP hydrolysis leads to export complex disassembly. The different exportins vary greatly in their substrate range. Recent structural studies of both protein- and RNA-specific exporters have illuminated how exportins bind their cargoes, how Ran triggers cargo loading and how export complexes are disassembled in the cytoplasm. Here, we review the current state of knowledge and highlight emerging principles as well as prevailing questions.

  14. Materials by Design-A Perspective From Atoms to Structures.

    PubMed

    Buehler, Markus J

    2013-02-01

    Biological materials are effectively synthesized, controlled, and used for a variety of purposes-in spite of limitations in energy, quality, and quantity of their building blocks. Whereas the chemical composition of materials in the living world plays a some role in achieving functional properties, the way components are connected at different length scales defines what material properties can be achieved, how they can be altered to meet functional requirements, and how they fail in disease states and other extreme conditions. Recent work has demonstrated this by using large-scale computer simulations to predict materials properties from fundamental molecular principles, combined with experimental work and new mathematical techniques to categorize complex structure-property relationships into a systematic framework. Enabled by such categorization, we discuss opportunities based on the exploitation of concepts from distinct hierarchical systems that share common principles in how function is created, linking music to materials science.

  15. Ran-dependent nuclear export mediators: a structural perspective

    PubMed Central

    Güttler, Thomas; Görlich, Dirk

    2011-01-01

    Nuclear export is an essential eukaryotic activity. It proceeds through nuclear pore complexes (NPCs) and is mediated by soluble receptors that shuttle between nucleus and cytoplasm. RanGTPase-dependent export mediators (exportins) constitute the largest class of these carriers and are functionally highly versatile. All of these exportins load their substrates in response to RanGTP binding in the nucleus and traverse NPCs as ternary RanGTP–exportin–cargo complexes to the cytoplasm, where GTP hydrolysis leads to export complex disassembly. The different exportins vary greatly in their substrate range. Recent structural studies of both protein- and RNA-specific exporters have illuminated how exportins bind their cargoes, how Ran triggers cargo loading and how export complexes are disassembled in the cytoplasm. Here, we review the current state of knowledge and highlight emerging principles as well as prevailing questions. PMID:21878989

  16. [Nucleotide receptors--structure and function, history and perspectives].

    PubMed

    Barańska, Jolanta

    2014-01-01

    First nucleotide receptors were discovered by Geoffrey Burnstock in 70ties of the last century, as a purinoreceptors activated by ATP. It was further found that they may be activated both by purine and pyrimidine nucleotides and their name was changed to nucleotide receptors. They are divided into two fsamilies: P1, activated by adenosine and P2, activated by nucleotides which are further divided into P2X and P2Y subfamilies. P2X are ionotropic receptors activated by ATP, P2Y (as the P1) are metabotropic receptors coupled with protein G. P2Y receptors are activated by ATP, ADP, UTP, UDP and UDP-sugar derivatives. This review describes early history of extracellular nucleotide signaling studies and presents current knowledge of the particular nucleotide receptors subtypes. The article also describes the structure and functional roles of these receptors and speculates about future research and therapeutic directions in this field.

  17. Structural and Electronic Properties of Isolated Nanodiamonds: A Theoretical Perspective

    SciTech Connect

    Raty, J; Galli, G

    2004-09-09

    Nanometer sized diamond has been found in meteorites, proto-planetary nebulae and interstellar dusts, as well as in residues of detonation and in diamond films. Remarkably, the size distribution of diamond nanoparticles appears to be peaked around 2-5 nm, and to be largely independent of preparation conditions. Using ab-initio calculations, we have shown that in this size range nanodiamond has a fullerene-like surface and, unlike silicon and germanium, exhibit very weak quantum confinement effects. We called these carbon nanoparticles bucky-diamonds: their atomic structure, predicted by simulations, is consistent with many experimental findings. In addition, we carried out calculations of the stability of nanodiamond which provided a unifying explanation of its size distribution in extra-terrestrial samples, and in ultra-crystalline diamond films. Here we present a summary of our theoretical results and we briefly outline work in progress on doping of nanodiamond with nitrogen.

  18. Structure, function and evolution of the gas exchangers: comparative perspectives

    PubMed Central

    Maina, JN

    2002-01-01

    Over the evolutionary continuum, animals have faced similar fundamental challenges of acquiring molecular oxygen for aerobic metabolism. Under limitations and constraints imposed by factors such as phylogeny, behaviour, body size and environment, they have responded differently in founding optimal respiratory structures. A quintessence of the aphorism that ‘necessity is the mother of invention’, gas exchangers have been inaugurated through stiff cost–benefit analyses that have evoked transaction of trade-offs and compromises. Cogent structural–functional correlations occur in constructions of gas exchangers: within and between taxa, morphological complexity and respiratory efficiency increase with metabolic capacities and oxygen needs. Highly active, small endotherms have relatively better-refined gas exchangers compared with large, inactive ectotherms. Respiratory structures have developed from the plain cell membrane of the primeval prokaryotic unicells to complex multifunctional ones ofthe modern Metazoa. Regarding the respiratory medium used to extract oxygen from, animal life has had only two choices – water or air – within the biological range of temperature and pressure the only naturally occurring respirable fluids. In rarer cases, certain animalshave adapted to using both media. Gills (evaginated gas exchangers) are the primordial respiratory organs: they are the archetypal water breathing organs. Lungs (invaginated gas exchangers) are the model air breathing organs. Bimodal (transitional) breathers occupy the water–air interface. Presentation and exposure of external (water/air) and internal (haemolymph/blood) respiratory media, features determined by geometric arrangement of the conduits, are important features for gas exchange efficiency: counter-current, cross-current, uniform pool and infinite pool designs have variably developed. PMID:12430953

  19. School nurses' perspectives on managing mental health problems in children and young people.

    PubMed

    Pryjmachuk, Steven; Graham, Tanya; Haddad, Mark; Tylee, Andre

    2012-03-01

    To explore the views of school nurses regarding mental health problems in young people and their potential for engaging in mental health work with this client group. Mental health problems in children and young people are an important public health issue. Universal children's services play a key role in identifying and managing these problems and, while school nurses have an important function in this work, little is known about their views on this aspect of their role. A qualitative research design employing focus group methodology. School nurses (n = 33) were purposively sampled from four school nursing teams in two English cities for a series of focus groups. The focus group data were audio-recorded, transcribed and subsequently analysed using 'framework'. Four principal themes emerged from the data. In these themes, school nurses were found to value their involvement with the mental health of young people, recognising this as an important area of practice. Several obstacles to their work in this area were identified: heavy workloads, professional rivalries, a lack of confidence and limited education and training opportunities. The importance of support from local specialist mental health teams was emphasised. School nurses can be engaged in mental health work though, as public health specialists, their role should focus on health promotion, assessment, signposting and early intervention activities. To facilitate mental health work, school nurses are able to draw on established interpersonal skills and supportive networks; however, workload and a lack of confidence need to be managed and it is important that they are supported by constructive relationships with local specialist mental health teams. This study has implications for nurses and healthcare practitioners interested in enhancing the mental health of children and young people in school settings. © 2011 Blackwell Publishing Ltd.

  20. Raman-based geobarometry of ultrahigh-pressure metamorphic rocks: applications, problems, and perspectives.

    PubMed

    Korsakov, Andrey V; Zhukov, Vladimir P; Vandenabeele, Peter

    2010-08-01

    Raman-based geobarometry has recently become increasingly popular because it is an elegant way to obtain information on peak metamorphic conditions or the entire pressure-temperature-time (P-T-t) path of metamorphic rocks, especially those formed under ultrahigh-pressure (UHP) conditions. However, several problems need to be solved to get reliable estimates of metamorphic conditions. In this paper we present some examples of difficulties which can arise during the Raman spectroscopy study of solid inclusions from ultrahigh-pressure metamorphic rocks.

  1. Metals for Cryotank Structures. Present and Future: MSFC Perspective

    NASA Technical Reports Server (NTRS)

    Vaughn, Timothy P.

    1999-01-01

    The Cryogenic Tank Technology Program (CTTP) program has been a cooperative effort between NASA LARC, NASA MSFC, NASA Headquarters, and industry (Lockheed Martin Aeronautics, Lockheed Martin Manned Space Systems, Wyman Gordon, and Ladish). The scope of the CTTP is to develop state-of-the-art, flight-size, flight-quality, low cost hardware, and use this hardware to design, fabricate and test an all aluminum-lithium, all near net shape-component 14' diameter cryogenic tank with a unique low profile bulkhead design. The logical conclusion to the CTTP is to validate these various technologies to a Technology Readiness Level (TRL) of 6 through the proposed structural test program. The CTTP supports the advancement of key enabling technologies required for aluminum lithium cryogenic tanks. The technologies are focused towards innovative and low cost manufacturing processes such as near net shape technologies: one piece spun formed domes, extruded barrel panels, and one piece roll forged ring frames. Other innovative technologies include the friction stir weld process and weight-efficient low profile bulkhead designs. All of these technologies are of primary importance for NASA's mission plan for reusable and expendable launch vehicles. This program fills the niche for an all 2195 aluminum lithium alloy cryogenic tank which is not being covered by existing NASA technology work.

  2. A Perspective: Engineering Periosteum for Structural Bone Graft Healing

    PubMed Central

    Awad, Hani A.; O’Keefe, Regis J.; Guldberg, Robert E.; Schwarz, Edward M.

    2008-01-01

    Autograft is superior to both allograft and synthetic bone graft in repair of large structural bone defect largely due to the presence of multipotent mesenchymal stem cells in periosteum. Recent studies have provided further evidence that activation, expansion and differentiation of the donor periosteal progenitor cells are essential for the initiation of osteogenesis and angiogenesis of donor bone graft healing. The formation of donor cell-derived periosteal callus enables efficient host-dependent graft repair and remodeling at the later stage of healing. Removal of periosteum from bone autograft markedly impairs healing whereas engraftment of multipotent mesenchymal stem cells on bone allograft improves healing and graft incorporation. These studies provide rationale for fabrication of a biomimetic periosteum substitute that could fit bone of any size and shape for enhanced allograft healing and repair. The success of such an approach will depend on further understanding of the molecular signals that control inflammation, cellular recruitment as well as mesenchymal stem cell differentiation and expansion during the early phase of the repair process. It will also depend on multidisciplinary collaborations between biologists, material scientists and bioengineers to address issues of material selection and modification, biological and biomechanical parameters for functional evaluation of bone allograft healing. PMID:18509709

  3. Composites for Cryotank Structures. Present and Future: MSFC Perspective

    NASA Technical Reports Server (NTRS)

    Vaughn, Timothy P.

    1999-01-01

    The development of reusable launch vehicle systems for a single stage to orbit vehicle requires vehicles at liftoff with 85% to 94% of its mass consisting exclusively of propellants. These dry mass requirements drive designs to utilize stronger, lighter weight materials for structures. This technology development focus has allowed the introduction of composite materials in lieu of conventional metallic materials due to their higher specific strengths. Composite materials were successfully used for the liquid hydrogen tanks for the DC-XA, and a multi-lobed liquid hydrogen tank will be employed for the X-33. Another potential non-traditional application for composite materials is for liquid oxygen tanks, which is still being investigated. Traditionally, organic materials have been avoided wherever possible, due the potential fire hazard and the fact that composites fail conventional oxygen compatibility requirements. However, the potential weight savings warrant the investigation of the use of polymeric composite materials in oxygen environments. Since composites fail the conventional, time-proven test methods because they are considered flammable by test, we have embarked on an innovative approach to oxygen compatibility testing and evaluation focused on the use environments and attempts to eliminate or "design away" all potential ignition sources. Oxygen compatibility is defined as the ability of a material to coexist with oxygen and potential ignition sources with an acceptable, manageable degree of risk.

  4. Recent advances in reduction methods for nonlinear problems. [in structural mechanics

    NASA Technical Reports Server (NTRS)

    Noor, A. K.

    1981-01-01

    Status and some recent developments in the application of reduction methods to nonlinear structural mechanics problems are summarized. The aspects of reduction methods discussed herein include: (1) selection of basis vectors in nonlinear static and dynamic problems, (2) application of reduction methods in nonlinear static analysis of structures subjected to prescribed edge displacements, and (3) use of reduction methods in conjunction with mixed finite element models. Numerical examples are presented to demonstrate the effectiveness of reduction methods in nonlinear problems. Also, a number of research areas which have high potential for application of reduction methods are identified.

  5. [Horizons and perspectives on the problem of non--responders to cardiac resynchronization therapy.

    PubMed

    Carità, Patrizia; Corrado, Egle; Pontone, Gianluca; Curnis, Antonio; Nogara, Angela; Mignano, Antonino; Verdecchia, Massimo; Ciaramitaro, Gianfranco; Novo, Salvatore; Coppola, Giuseppe

    2017-01-01

    Cardiac resynchronization therapy (CRT) has been shown as a successful strategy in the treatment of patients with heart failure and electrical dyssincrony. However, a significant proportion of implanted patients fails to respond sufficiently or in a predictable manner. Consequently, non response to CRT remains a valuable problem in clinical practice. In order to improve CRT response and long-term clinical benefits, the proper evaluation of patient's global frialty, the technology improvement, the multimodality imaging approach and the use of simple and low cost electrographic parameters (to verify effective biventricular capture and QRS narrowing) could play a important role. Therefore, the integration of various medical expertises (clinical cardiology, cardiac advanced imaging, electrophysiology) is a crucial element in order to achive the maximal benefits from this promising tecnique. In the multistep process (from patients evaluation to results verification) the follow-up even from the earliest post implantation phase, should be managed with great attention having the potential for impact the prognosis. This brief review focus the problem of non responder to CRT, giving particular attention to the different variables that may play a role (comorbilities, improvement in the tecnology of device implantation, role of multimodality imaging and electrocardiographic parameters).

  6. The Dreyfus model of clinical problem-solving skills acquisition: a critical perspective

    PubMed Central

    Peña, Adolfo

    2010-01-01

    Context The Dreyfus model describes how individuals progress through various levels in their acquisition of skills and subsumes ideas with regard to how individuals learn. Such a model is being accepted almost without debate from physicians to explain the ‘acquisition’ of clinical skills. Objectives This paper reviews such a model, discusses several controversial points, clarifies what kind of knowledge the model is about, and examines its coherence in terms of problem-solving skills. Dreyfus' main idea that intuition is a major aspect of expertise is also discussed in some detail. Relevant scientific evidence from cognitive science, psychology, and neuroscience is reviewed to accomplish these aims. Conclusions Although the Dreyfus model may partially explain the ‘acquisition’ of some skills, it is debatable if it can explain the acquisition of clinical skills. The complex nature of clinical problem-solving skills and the rich interplay between the implicit and explicit forms of knowledge must be taken into consideration when we want to explain ‘acquisition’ of clinical skills. The idea that experts work from intuition, not from reason, should be evaluated carefully. PMID:20563279

  7. The Dreyfus model of clinical problem-solving skills acquisition: a critical perspective.

    PubMed

    Peña, Adolfo

    2010-06-14

    The Dreyfus model describes how individuals progress through various levels in their acquisition of skills and subsumes ideas with regard to how individuals learn. Such a model is being accepted almost without debate from physicians to explain the 'acquisition' of clinical skills. This paper reviews such a model, discusses several controversial points, clarifies what kind of knowledge the model is about, and examines its coherence in terms of problem-solving skills. Dreyfus' main idea that intuition is a major aspect of expertise is also discussed in some detail. Relevant scientific evidence from cognitive science, psychology, and neuroscience is reviewed to accomplish these aims. Although the Dreyfus model may partially explain the 'acquisition' of some skills, it is debatable if it can explain the acquisition of clinical skills. The complex nature of clinical problem-solving skills and the rich interplay between the implicit and explicit forms of knowledge must be taken into consideration when we want to explain 'acquisition' of clinical skills. The idea that experts work from intuition, not from reason, should be evaluated carefully.

  8. Near Earth Objects and Cascading Effects from the Policy Perspective: Implications from Problem and Solution Definition

    NASA Astrophysics Data System (ADS)

    Lindquist, Eric

    2016-04-01

    The characterization of near-Earth-objects (NEOs) in regard to physical attributes and potential risk and impact factors presents a complex and complicates scientific and engineering challenge. The societal and policy risks and impacts are no less complex, yet are rarely considered in the same context as material properties or related factors. Further, NEO impacts are typically considered as discrete events, not as initial events in a dynamic cascading system. The objective of this contribution is to position the characterization of NEOs within the public policy process domain as a means to reflect on the science-policy nexus in regard to risks and multi-hazard impacts associated with these hazards. This will be accomplished through, first, a brief overview of the science-policy nexus, followed by a discussion of policy process frameworks, such as agenda setting and the multiple streams model, focusing events, and punctuated equilibrium, and their application and appropriateness to the problem of NEOs. How, too, for example, does NEO hazard and risk compare with other low probability, high risk, hazards in regard to public policy? Finally, we will reflect on the implications of alternative NEO "solutions" and the characterization of the NEO "problem," and the political and public acceptance of policy alternatives as a way to link NEO science and policy in the context of the overall NH9.12 panel.

  9. Characterization of NEOs from the Policy Perspective: Implications from Problem and Solution Definitions

    NASA Astrophysics Data System (ADS)

    Lindquist, E.

    2015-12-01

    The characterization of near-Earth-objects (NEOs) in regard to physical attributes and potential risk and impact factors presents a complex and complicates scientific and engineering challenge. The societal and policy risks and impacts are no less complex, yet are rarely considered in the same context as material properties or related factors. The objective of this contribution is to position the characterization of NEOs within the public policy process domain as a means to reflect on the science-policy nexus in regard to risks associated with NEOs. This will be accomplished through, first, a brief overview of the science-policy nexus, followed by a discussion of several policy process frameworks, such as agenda setting and the multiple streams model, focusing events, and punctuated equilibrium, and their application and appropriateness to the problem of NEOs. How, too, for example, does NEO hazard and risk compare with other low probability, high risk, hazards in regard to public policy? Finally, we will reflect on the implications of alternative NEO "solutions" and the characterization of the NEO "problem," and the political and public acceptance of policy alternatives as a way to link NEO science and policy in the context of the overall NH004 panel.

  10. Richat Structure, Mauritania, Perspective View, Landsat Image over SRTM Elevation

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This prominent circular feature, known as the Richat Structure, in the Sahara desert of Mauritania is often noted by astronauts because it forms a conspicuous 50-kilometer-wide (30-mile-wide) bull's-eye on the otherwise rather featureless expanse of the desert. Initially mistaken for a possible impact crater, it is now known to be an eroded circular anticline (structural dome) of layered sedimentary rocks.

    Extensive sand dunes occur in this region and the interaction of bedrock topography, wind, and moving sand is evident in this scene. Note especially how the dune field ends abruptly short of the cliffs at the far right as wind from the northeast (lower right) apparently funnels around the cliff point, sweeping clean areas near the base of the cliff. Note also the small isolated peak within the dune field. That peak captures some sand on its windward side, but mostly deflects the wind and sand around its sides, creating a sand-barren streak that continues far downwind.

    This view was generated from a Landsat satellite image draped over an elevation model produced by the Shuttle Radar Topography Mission (SRTM). The view uses a 6-times vertical exaggeration to greatly enhance topographic expression. For vertical scale, note that the height of the mesa ridge in the back center of the view is about 285 meters (about 935 feet) tall. Colors of the scene were enhanced by use of a combination of visible and infrared bands, which helps to differentiate bedrock (browns), sand (yellow, some white), minor vegetation in drainage channels (green), and salty sediments (bluish whites). Some shading of the elevation model was included to further highlight the topographic features.

    Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR

  11. Richat Structure, Mauritania, Perspective View, Landsat Image over SRTM Elevation

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This prominent circular feature, known as the Richat Structure, in the Sahara desert of Mauritania is often noted by astronauts because it forms a conspicuous 50-kilometer-wide (30-mile-wide) bull's-eye on the otherwise rather featureless expanse of the desert. Initially mistaken for a possible impact crater, it is now known to be an eroded circular anticline (structural dome) of layered sedimentary rocks.

    Extensive sand dunes occur in this region and the interaction of bedrock topography, wind, and moving sand is evident in this scene. Note especially how the dune field ends abruptly short of the cliffs at the far right as wind from the northeast (lower right) apparently funnels around the cliff point, sweeping clean areas near the base of the cliff. Note also the small isolated peak within the dune field. That peak captures some sand on its windward side, but mostly deflects the wind and sand around its sides, creating a sand-barren streak that continues far downwind.

    This view was generated from a Landsat satellite image draped over an elevation model produced by the Shuttle Radar Topography Mission (SRTM). The view uses a 6-times vertical exaggeration to greatly enhance topographic expression. For vertical scale, note that the height of the mesa ridge in the back center of the view is about 285 meters (about 935 feet) tall. Colors of the scene were enhanced by use of a combination of visible and infrared bands, which helps to differentiate bedrock (browns), sand (yellow, some white), minor vegetation in drainage channels (green), and salty sediments (bluish whites). Some shading of the elevation model was included to further highlight the topographic features.

    Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR

  12. The Role of Content Knowledge in Ill-Structured Problem Solving for High School Physics Students

    NASA Astrophysics Data System (ADS)

    Milbourne, Jeff; Wiebe, Eric

    2017-03-01

    While Physics Education Research has a rich tradition of problem-solving scholarship, most of the work has focused on more traditional, well-defined problems. Less work has been done with ill-structured problems, problems that are better aligned with the engineering and design-based scenarios promoted by the Next Generation Science Standards. This study explored the relationship between physics content knowledge and ill-structured problem solving for two groups of high school students with different levels of content knowledge. Both groups of students completed an ill-structured problem set, using a talk-aloud procedure to narrate their thought process as they worked. Analysis of the data focused on identifying students' solution pathways, as well as the obstacles that prevented them from reaching "reasonable" solutions. Students with more content knowledge were more successful reaching reasonable solutions for each of the problems, experiencing fewer obstacles. These students also employed a greater variety of solution pathways than those with less content knowledge. Results suggest that a student's solution pathway choice may depend on how she perceives the problem.

  13. The Use of Video Cases in a Multimedia Learning Environment for Facilitating High School Students' Inquiry into a Problem from Varying Perspectives

    ERIC Educational Resources Information Center

    Zydney, Janet Mannheimer; Grincewicz, Amy

    2011-01-01

    This study investigated the connection between the use of video cases within a multimedia learning environment and students' inquiry into a socio-scientific problem. The software program was designed based on principles from the Cognitive Flexibility Theory (CFT) and incorporated video cases of experts with differing perspectives. Seventy-nine…

  14. Clinician and Parent Perspectives on Parent and Family Contextual Factors that Impact Community Mental Health Services for Children with Behavior Problems

    ERIC Educational Resources Information Center

    Baker-Ericzen, Mary J.; Jenkins, Melissa M.; Brookman-Frazee, Lauren

    2010-01-01

    The present study employed qualitative methods to examine multiple stakeholder perspectives regarding the role of parent and family contextual factors on community child mental health treatment for children with behavior problems. Findings suggest agreement between clinicians and parents on the number, types and importance of parent and family…

  15. Clinician and Parent Perspectives on Parent and Family Contextual Factors that Impact Community Mental Health Services for Children with Behavior Problems

    ERIC Educational Resources Information Center

    Baker-Ericzen, Mary J.; Jenkins, Melissa M.; Brookman-Frazee, Lauren

    2010-01-01

    The present study employed qualitative methods to examine multiple stakeholder perspectives regarding the role of parent and family contextual factors on community child mental health treatment for children with behavior problems. Findings suggest agreement between clinicians and parents on the number, types and importance of parent and family…

  16. The mediating role of perceived peer support in the relation between quality of attachment and internalizing problems in adolescence: a longitudinal perspective.

    PubMed

    Pace, Ugo; Zappulla, Carla; Di Maggio, Rosanna

    2016-10-01

    The study was aimed to verify, from a longitudinal perspective, whether perceived peer support would mediate the relationship between attachment and internalizing problems. Longitudinal participants included 482 adolescents (245 boys) aged 14-15 years in Wave 1 and 17-18 years in Wave 2. Participants in Wave 1 completed the Relationship Questionnaire, and those in Wave 2 completed the Social Support Questionnaire and the Youth Self-Report. Results showed that secure attachment positively predicted high levels of perceived peer support and negatively predicted internalizing problems, whereas fearful and preoccupied attachment negatively predicted perceived peer support and positively predicted internalizing problems. The mediation models showed that perceived peer support partially mediated the relationship between secure attachment and internalizing problems as well as between preoccupied attachment and internalizing problems and between fearful attachment and internalizing problems. Our results confirm the role of subjective perception of peer support in contributing to the prediction of internalizing problems beyond attachment styles.

  17. Modeling of III-nitride light-emitting diodes: progress, problems, and perspectives

    NASA Astrophysics Data System (ADS)

    Karpov, Sergey Yu.

    2011-02-01

    Recent progress in III-nitride LED modeling is reviewed with the focus on physical models that provide a better understanding of such hot issues, as factors limiting the internal quantum efficiency of light emission and high-current efficiency droop, polarization doping in graded-composition III-nitride alloys and its utilization in LEDs, current crowding in LED dice and its impact on the light extraction efficiency, and optimal light conversion in white LED lamps. Specific features of III-nitride materials, their impact on the LED operation, and models accounting for these features are considered. Insufficient understanding of transport mechanisms of non-equilibrium electrons and holes and their localization in InGaN inhomogeneous active regions are discussed along with other still unsolved problems. Influence of technological factors on LED heterostructures and their operation is argued in the context of further model developments.

  18. Problems in transition and quality of care: perspectives of breast cancer survivors

    PubMed Central

    Roundtree, Aimee Kendall; Giordano, Sharon H.; Price, Andrea; Suarez-Almazor, Maria E.

    2011-01-01

    Purpose We conducted a qualitative study to explore breast cancer survivors’ perceptions and attitudes about their current healthcare utilization, screening, and information needs. Methods We completed eight focus groups of breast cancer survivors. We included women, adult survivors, with an initial diagnosis of breast cancer in the year 2000, treated, and without a recurrence as per medical record. To analyze transcripts, we used grounded theory methods, wherein unexpected themes and direct answers emerged from consensus between co-coders. Results Focus groups included 33 participants, the majority of whom were white (84.8%), college-educated (66.7%), and covered by private medical insurance (75.7%) or Medicare (27.3%). Participants’ perceptions and attitudes about care were framed in terms of personal experiences (including facing barriers to screening, feeling in limbo in the healthcare system, having problems with communication with and between physicians, confusion about symptoms, and using self-prescribe remedies), personal attitudes (including strong opinions about what survivorship means, concerns about recurrence, and changes in self-perception and agency), and social influences (including modeling others’ behaviors, changes in social life, and listening to family). Conclusion Survivorship attitudes, recurrence fears, memories, and self-perceptions were influential personal factors in addition to self-efficacy. Solutions such as providing a cancer treatment summary might resolve many of the problems by consolidating and making readily available the numerous medical history and recommendations that survivors accrue over time, switching from provider to provider. Clinicians must also implement communication changes in their interactions with patients to enhance positive attitudes and behaviors, and leverage social influences. PMID:21140173

  19. The adaptability rating for military aeronautics: an historical perspective of a continuing problem.

    PubMed

    Mills, J G; Jones, D R

    1984-06-01

    Healthy candidates for military flying training may vary considerably in their ability and in their motivation to fly. A variety of tests are used to predict flying ability, but motivation may be assessed only through such subjective measures as a semi-structured interview. This paper reviews the historical background of such interviews in the U.S. Army and the U.S. Air Force, and suggests some possible improvements.

  20. Opportunity Structure for Gambling and Problem Gambling among Employees in the Transport Industry

    ERIC Educational Resources Information Center

    Revheim, Tevje; Buvik, Kristin

    2009-01-01

    Working conditions for employees in the transport sector might present an opportunity structure for gambling by providing access to gambling during the workday. This study investigates connections between opportunity structure, gambling during the workday, and gambling problems among employees in the transport sector. Data has been collected from…