WorldWideScience

Sample records for as low as reasonably achievable

  1. Pacific Northwest Laboratory plan to maintain radiation exposure as low as reasonably achievable (ALARA)

    International Nuclear Information System (INIS)

    This document describes the radiation safety program at the Pacific Northwest Laboratory (PNL). The practices and administrative policies of this program support the principles of ALARA (to maintain radiation exposure as low as reasonably achievable). This document also describes a program to establish safety goals at PNL to help ensure that operations are conducted according to ALARA principles

  2. As low as reasonably achievable (ALARA): is it appropriate for low level exposures?

    International Nuclear Information System (INIS)

    Through various researches and investigations it has been established that high doses of ionizing radiation are harmful to health and there is a linear relationship between dose and the effect. There is substantial controversy regarding the biological and health effects of low doses of ionizing radiation in humans and the biota, in vitro and in vivo despite the large amount of work carried out (both laboratory and epidemiological). By low-level exposure, we mean the exposure to radiation levels comparable to those encountered in the natural environment (ambient radiation level). The proponents of the ALARA policy are the believers of LNT hypothesis adopted by major scientific, official and governmental organizations such as ICRP, NCRP, the NAS-NRC etc. for risk assessment, according to which exposure to any amount of radiation, no matter howsoever small is potentially harmful. The idea that the dose to radiation worker should be As Low As Reasonably Achievable (ALARA) is only appropriate if small doses have a risk. Current radiation risk estimates, drawn by linear extrapolation, from high dose and dose rate of radiation to zero dose, clearly ignore the effects of the repair of DNA- the target of radiation damage. If the hormetic effect is added to the effect predicted by the LNT hypothesis, the resultant effect will be somewhat different from that predicted by the LNT hypothesis alone. Excellent human data show that a moderate increase in background radiation decreases the risk of cancer and significantly increases longevity. There are strong arguments, both experimental and epidemiological, which support the radiation hormesis (beneficial effects of low-level ionizing radiation). In the present paper, we propose to highlight the results of a comprehensive study of the available literature, data and reports of various radiation exposure and protection studies carried out in India and abroad. In conclusion, we find that the radiation hormesis contradicts the

  3. Principles and practices for keeping occupational radiation exposures at medical institutions as low as reasonably achievable

    International Nuclear Information System (INIS)

    This report is a companion document to Regulatory Guide 8.18, Information Relevant to Ensuring that Occupational Radiation Exposures at Medical Institutions Will Be As Low As Reasonably Achievable. Both documents have now been revised to incorporate many good suggestions received after the original documents were published for comment. This report is a compendium of good practices and helpful information derived from the experience of the radiological and health physics professions and is not be construed in any way as additional regulatory requirements of the Nuclear Regulatory Commission. The information presented, including comprehensive checklists of facilities, equipment, and procedures that should be considered for working with NRC-licensed materials in all types of hospital activities, is intended to aid the NRC licensee in fulfilling the philosophy of maintaining radiation exposures of employees, patients, visitors, and the public as low as reasonably achievable (ALARA). Each subsection of this report is designed to include the major radiation safety considerations pertaining to the respective hospital function. Thus, the busy health professional will neeed to read only a few pages of this document at any one time to obtain the information needed

  4. Methodology for making environmental as low as reasonably achievable (ALARA) determinations

    International Nuclear Information System (INIS)

    An overall evaluation concept for use in making differential cost-benefit analyses in environmental as low as reasonably achievable (ALARA) determinations is being implemented by Rockwell Hanford Operations. This evaluation includes consideration of seven categories: (1) capital costs; (2) operating costs; (3) state of the art; (4) safety; (5) accident or upset consequences; (6) reliability, operability, and maintainability; and (7) decommissionability. Appropriate weighting factors for each of these categories are under development so that ALARA determinations can be made by comparing scores of alternative proposals for facility design, operations, and upgrade. This method of evaluation circumvents the traditional basis of a stated monetary sum per person-rem of dose commitment. This alternative was generated by advice from legal counsel who advised against formally pursuing this avenue of approach to ALARA for environmental and occupational dose commitments

  5. Guide to reducing radiation exposure to as low as reasonably achievable (ALARA)

    Energy Technology Data Exchange (ETDEWEB)

    Kathren, R.L.

    1980-04-01

    This document is designed to provide DOE contractor personnel with general guidance regarding programs and techniques to reduce radiation exposures to as low as reasonably achievable (ALARA). Thus it is directed towards a broad audience, and should have special relevance and interest for operating management as well as radiation protection personnel. It is well recognized that each contractor has needs specific and critical to its radiation protection program. Hence no single set of specific and detailed criteria can be set down as a prescription for achieving the ALARA goal. Rather, general guidance in the form of broad principles is given in order to acquaint management with ALARA needs and concepts. The purpose is to encourage maximum management support of the technical personnel responsible for carrying out day-to-day radiation protection activities. Although primarily written for management, this document also contains technical guidance of potential value to those directly involved in radiation protection activities. Again it should be stressed that what is provided is guidance, and is therefore not mandatory.

  6. Guide to reducing radiation exposure to as low as reasonably achievable (ALARA)

    International Nuclear Information System (INIS)

    This document is designed to provide DOE contractor personnel with general guidance regarding programs and techniques to reduce radiation exposures to as low as reasonably achievable (ALARA). Thus it is directed towards a broad audience, and should have special relevance and interest for operating management as well as radiation protection personnel. It is well recognized that each contractor has needs specific and critical to its radiation protection program. Hence no single set of specific and detailed criteria can be set down as a prescription for achieving the ALARA goal. Rather, general guidance in the form of broad principles is given in order to acquaint management with ALARA needs and concepts. The purpose is to encourage maximum management support of the technical personnel responsible for carrying out day-to-day radiation protection activities. Although primarily written for management, this document also contains technical guidance of potential value to those directly involved in radiation protection activities. Again it should be stressed that what is provided is guidance, and is therefore not mandatory

  7. Health physics manual of good practices for reducing radiation exposure to levels that are as low as reasonably achievable (ALARA)

    International Nuclear Information System (INIS)

    A primary objective of the US Department of Energy (DOE) health physics and radiation protection program has been to limit radiation exposures to those levels that are as low as reasonably achievable (ALARA). As a result, the ALARA concept developed into a program and a set of operational principles to ensure that the objective was consistently met. Implementation of these principles required that a guide be produced. The original ALARA guide was issued by DOE in 1980 to promote improved understanding of ALARA concepts within the DOE community and to assist those responsible for operational ALARA activities in attaining their goals. Since 1980, additional guidance has been published by national and international organizations to provide further definition and clarification to ALARA concepts. As basic ALARA experience increased, the value and role of the original guide prompted the DOE Office of Nuclear Safety (ONS) to support a current revision. The revised manual of good practices includes six sections: 1.0 Introduction, 2.0 Administration, 3.0 Optimization, 4.0 Setting and Evaluating ALARA Goals, 5.0 Radiological Design, and 6.0 Conduct of Operations. The manual is directed primarily to contractor and DOE staff who are responsible for conduct and overview of radiation protection and ALARA programs at DOE facilities. The intent is to provide sufficient guidance such that the manual, if followed, will ensure that radiation exposures are maintained as low as reasonably achievable and will establish the basis for a formally structured and auditable program. 118 refs., 16 figs., 3 tabs

  8. Health physics manual of good practices for reducing radiation exposure to levels that are as low as reasonably achievable (ALARA)

    Energy Technology Data Exchange (ETDEWEB)

    Herrington, W.N.; Higby, D.P.; Kathren,., R.L.; Merwin, S.E.; Stoetzel, G.A.

    1988-06-01

    A primary objective of the US Department of Energy (DOE) health physics and radiation protection program has been to limit radiation exposures to those levels that are as low as reasonably achievable (ALARA). As a result, the ALARA concept developed into a program and a set of operational principles to ensure that the objective was consistently met. Implementation of these principles required that a guide be produced. The original ALARA guide was issued by DOE in 1980 to promote improved understanding of ALARA concepts within the DOE community and to assist those responsible for operational ALARA activities in attaining their goals. Since 1980, additional guidance has been published by national and international organizations to provide further definition and clarification to ALARA concepts. As basic ALARA experience increased, the value and role of the original guide prompted the DOE Office of Nuclear Safety (ONS) to support a current revision. The revised manual of good practices includes six sections: 1.0 Introduction, 2.0 Administration, 3.0 Optimization, 4.0 Setting and Evaluating ALARA Goals, 5.0 Radiological Design, and 6.0 Conduct of Operations. The manual is directed primarily to contractor and DOE staff who are responsible for conduct and overview of radiation protection and ALARA programs at DOE facilities. The intent is to provide sufficient guidance such that the manual, if followed, will ensure that radiation exposures are maintained as low as reasonably achievable and will establish the basis for a formally structured and auditable program. 118 refs., 16 figs., 3 tabs.

  9. Computer Security: SAHARA - Security As High As Reasonably Achievable

    CERN Multimedia

    Stefan Lueders, Computer Security Team

    2015-01-01

    History has shown us time and again that our computer systems, computing services and control systems have digital security deficiencies. Too often we deploy stop-gap solutions and improvised hacks, or we just accept that it is too late to change things.    In my opinion, this blatantly contradicts the professionalism we show in our daily work. Other priorities and time pressure force us to ignore security or to consider it too late to do anything… but we can do better. Just look at how “safety” is dealt with at CERN! “ALARA” (As Low As Reasonably Achievable) is the objective set by the CERN HSE group when considering our individual radiological exposure. Following this paradigm, and shifting it from CERN safety to CERN computer security, would give us “SAHARA”: “Security As High As Reasonably Achievable”. In other words, all possible computer security measures must be applied, so long as ...

  10. Safety as high and as harmonized as reasonably achievable: Nuclear regulators facing globalization

    International Nuclear Information System (INIS)

    The use of nuclear energy and ionizing radiation is being extensively scrutinized once again in light of the present debate on its role in sustainable development and on global security problems. Nuclear power is an important feature of today's energy supply. Commercial nuclear generation is a mature, established technology, having accumulated over 40 years of successful operation. Yet nuclear power raises passions as do few other energy issues. Within countries and among them, both support and opposition are strong. Loyola de Palacio, the European Union Commissioner responsible for energy and transport, summed up the dilemma very succinctly: Either we shut down the nuclear sector and give up on Kyoto, or we do not shut down the nuclear sector and we respect Kyoto. It is as simple as that: sometimes you have to put it crudely so that people understand. What is the role of nuclear regulators in this environment? The primary objective of government intervention into nuclear business is to allow humankind to maximize the benefits and minimize the risks emanating from nuclear sciences and their applications. Because both the nuclear power industry and the societal context within which it is regulated are dynamic, regulators must continuously assess their approaches to regulation to best achieve their regulatory mandate. This includes adjusting the boundaries of activity between the plant and the regulator. That is, working out the practical approaches that allow the power reactor operator/owner to achieve and maintain safety while allowing the regulatory body to assure itself and the public that appropriate levels of safety are achieved and maintained

  11. ALARA [as low as reasonably achievable] engineering at Department of Energy facilities: Bibliography of selected readings in radiation protection and ALARA

    International Nuclear Information System (INIS)

    This report is the first in the series of bibliographies supporting the efforts at the Brookhaven National Laboratory ALARA Center on dose reduction at DOE facilities. Abstracts for this bibliography were selected from proceedings of technical meetings, journals, research reports, and searches of the DOE Energy Data Base. The abstracts included in this report relate to operational health physics as well as other subjects which have a bearing on dose reduction. Facilities covered include: radioactive waste, uranium enrichment, fabrication, unirradiated fissile materials storage, irradiated fissile material storage, reprocessing, decommissioning, recovery, hot laboratories, tritium production, reactors (research, test and production but not power reactors), and accelerators. We have also included material in improved design, materials selection, planning, and other topics which are related to dose-reduction efforts. The report contains 68 abstracts as well as subject and author indices

  12. Assessment as Evidential Reasoning

    Science.gov (United States)

    Gorin, Joanna S.

    2014-01-01

    Background/Context: Principles of evidential reasoning have often been discussed in the context of educational and psychological measurement with respect to construct validity and validity arguments. More recently, Mislevy proposed the metaphor of assessment as an evidentiary argument about students' learning and abilities given their…

  13. Working Memory and Dynamic Measures of Analogical Reasoning as Predictors of Children's Math and Reading Achievement

    Science.gov (United States)

    Stevenson, Claire E.; Bergwerff, Catharina E.; Heiser, Willem J.; Resing, Wilma C. M.

    2014-01-01

    Working memory and inductive reasoning ability each appear related to children's achievement in math and reading. Dynamic measures of reasoning, based on an assessment procedure including feedback, may provide additional predictive value. The aim of this study was to investigate whether working memory and dynamic measures of analogical…

  14. Clinical reasoning as social deliberation

    DEFF Research Database (Denmark)

    2014-01-01

    In this paper I will challenge the individualistic model of clinical reasoning. I will argue that sometimes clinical practice is rather machine-like, and information is called to mind and weighed, but the clinician is not just calculating how to use particular means to reach fixed ends. Often the...

  15. Emotional Intelligence as a Predictor of Leadership of Kuwaiti High and Low Achieving 11th Graders

    Science.gov (United States)

    Alnabhan, Mousa

    2010-01-01

    The current study examined the association between emotional intelligence (EI) and the Leadership components (L) of high school students in the state of Kuwait. The possibility of predicting each leadership component via emotional intelligence components was investigated for high and low achievers. A sample of 11th grade students from Kuwaiti…

  16. The Complexities of Realizing Community: Assistant Principals as Community Leaders in Persistently Low-Achieving Schools

    Science.gov (United States)

    Bukoski, Beth E.; Lewis, Tiffanie C.; Carpenter, Bradley W.; Berry, Matthew S.; Sanders, Kimberly N.

    2015-01-01

    Meaningful community involvement has been linked to enhancements in student achievement and quality of educational experiences. Assistant principals are positioned to build effective partnerships yet remain understudied in the leadership preparation field. This qualitative study investigated how assistant principals (N = 9) serving historically…

  17. [Shared governance and reasonableness as ethical contributions to health policy].

    Science.gov (United States)

    Costa-Alcaraz, Ana M; Calvo-Rigual, Fernando; Siurana-Aparisi, Juan Carlos

    2013-01-01

    Health is one of the fundamental human rights. Recognizing it as a right means that the State has an obligation to ensure a minimum level of opportunities is maintained, and to restore it when lost. This minimum level may not be covered in periods of economic crisis, such as the one we are currently experiencing.Managed care, focused on economic questions, emerged after the crisis of 1973 in order to help make clinical decisions based on economic factors. In practice, the result of managed care was to turn economic cost control into an end in itself while forgetting about equity; something for which it has been challenged from an ethical perspective. Since then, many authors have attempted to reconcile efficiency and equity in health management, but the debate remains open.In this article, and basing our approach on the theories of P. Ruger and Norman Daniels, we argue that shared health governance and accountability for reasonableness can offer significant ethical contributions in the process of achieving an efficient and fair health system. In the model we propose, citizens, professionals and health institutions all play an active role in capacity building in the field of health. These capacities are related to healthy lifestyles, accessible and transparent information, the promotion of self-care, the acquisition of knowledge, skills and appropriate attitudes, leadership based on values and co-responsibility to achieve set goals in a reasonable way. If we develop these capacities, we will have used the current economic crisis as an opportunity for improving ethical practice in the field of health.

  18. [Shared governance and reasonableness as ethical contributions to health policy].

    Science.gov (United States)

    Costa-Alcaraz, Ana M; Calvo-Rigual, Fernando; Siurana-Aparisi, Juan Carlos

    2013-01-01

    Health is one of the fundamental human rights. Recognizing it as a right means that the State has an obligation to ensure a minimum level of opportunities is maintained, and to restore it when lost. This minimum level may not be covered in periods of economic crisis, such as the one we are currently experiencing.Managed care, focused on economic questions, emerged after the crisis of 1973 in order to help make clinical decisions based on economic factors. In practice, the result of managed care was to turn economic cost control into an end in itself while forgetting about equity; something for which it has been challenged from an ethical perspective. Since then, many authors have attempted to reconcile efficiency and equity in health management, but the debate remains open.In this article, and basing our approach on the theories of P. Ruger and Norman Daniels, we argue that shared health governance and accountability for reasonableness can offer significant ethical contributions in the process of achieving an efficient and fair health system. In the model we propose, citizens, professionals and health institutions all play an active role in capacity building in the field of health. These capacities are related to healthy lifestyles, accessible and transparent information, the promotion of self-care, the acquisition of knowledge, skills and appropriate attitudes, leadership based on values and co-responsibility to achieve set goals in a reasonable way. If we develop these capacities, we will have used the current economic crisis as an opportunity for improving ethical practice in the field of health. PMID:23775103

  19. Using Analogy to Improve Abstract Conditional Reasoning in Adolescents: Not as Easy as It Looks

    Science.gov (United States)

    Markovits, Henry; Doyon, Celine

    2011-01-01

    Abstract reasoning refers to the ability to reason logically with premises that do not allow reference to knowledge about the real world. This form of reasoning is complex and difficult, and at the same time, it is critical for understanding science and mathematics. Two studies examined the use of analogy as a method to bridge reasoning with…

  20. Gender as a predictor for academic achievement

    Directory of Open Access Journals (Sweden)

    Endang Lestari

    2012-07-01

    penting profesionalisme, keberhasilan akademik mahasiswa   Abstract   Background: Professionalism is central to maintaining public’s trust in medical profession. Building professionalism during their study time in medical education is possible method to equip students with core attributes of professional behavior of doctor. However, the professional practice might influence not only their future job, but also their recent performance as students. This study aimed to identify the correlation between students’ demographic factors and core attributes of professionalism related to good grade point average achievement. Methods: Fourth year students of Faculty of Medicine Universitas Islam Sultan Agung Islamic in Semarang Indonesia took part in this cross sectional study. The core attributes of professionalism were assessed using short inventory “Assessment of Medical Student Professionalism”, which was developed by some experts using Delphi method. The students’ grade point average (GPA data were collected from the Information Technology Unit of the faculty. Analysis data using Cox-regression with constant time. Results: A total amount of 207 (out of 240 students participated in this study. Our final model indicates that none of the core attributes professionalism which predicts good grade point average (GPA achievement. Female than male students had 35% increased to be good GPA achievement [adjusted relative risk (RRa = 1.35; 95% confidence interval (CI = 1.05-1.74]. Conclusion: Female but none of the core attribute of professionalism students was noted to increase academic grade point average. (Health Science Indones 2010; 1: 43 - 50

  1. Social science as a tool in developing scientific thinking skills in underserved, low-achieving urban students.

    Science.gov (United States)

    Jewett, Elizabeth; Kuhn, Deanna

    2016-03-01

    Engagement in purposeful problem solving involving social science content was sufficient to develop a key set of inquiry skills in low-performing middle school students from an academically and economically disadvantaged urban public school population, with this skill transferring to a more traditional written scientific thinking assessment instrument 3weeks later. Students only observing their peers' activity or not participating at all failed to show these gains. Implications are addressed with regard to the mastery of scientific thinking skills among academically disadvantaged students. Also addressed are the efficacy of problem-based learning and the limits of observational learning.

  2. Deductive way of reasoning about the internet AS level topology

    Institute of Scientific and Technical Information of China (English)

    D´avid Szab´o; Attila K˝or¨osi; J´ozsef B´ır´o; Andr´as Guly´as

    2015-01-01

    Our current understanding about the AS level topology of the Internet is based on measurements and inductive-type models which set up rules describing the behavior (node and edge dynamics) of the individual ASes and generalize the consequences of these individual actions for the complete AS ecosystem using induction. In this paper we suggest a third, deductive approach in which we have premises for the whole AS system and the consequences of these premises are determined through deductive reasoning. We show that such a deductive approach can give complementary insights into the topological properties of the AS graph. While inductive models can mostly reflect high level statistics (e.g., degree distribution, clustering, diameter), deductive reasoning can identify omnipresent subgraphs and peering likelihood. We also propose a model, called YEAS, incorporating our deductive analytical findings that produces topologies contain both traditional and novel metrics for the AS level Internet.

  3. Using optimal combination of teaching-learning methods (open book assignment and group tutorials) as revision exercises to improve learning outcome in low achievers in biochemistry.

    Science.gov (United States)

    Rajappa, Medha; Bobby, Zachariah; Nandeesha, H; Suryapriya, R; Ragul, Anithasri; Yuvaraj, B; Revathy, G; Priyadarssini, M

    2016-07-01

    Graduate medical students of India are taught Biochemistry by didactic lectures and they hardly get any opportunity to clarify their doubts and reinforce the concepts which they learn in these lectures. We used a combination of teaching-learning (T-L) methods (open book assignment followed by group tutorials) to study their efficacy in improving the learning outcome. About 143 graduate medical students were classified into low (75%: group 3, n = 46) achievers, based on their internal assessment marks. After the regular teaching module on the topics "Vitamins and Enzymology", all the students attempted an open book assignment without peer consultation. Then all the students participated in group tutorials. The effects on the groups were evaluated by pre and posttests at the end of each phase, with the same set of MCQs. Gain from group tutorials and overall gain was significantly higher in the low achievers, compared to other groups. High and medium achievers obtained more gain from open book assignment, than group tutorials. The overall gain was significantly higher than the gain obtained from open book assignment or group tutorials, in all three groups. All the three groups retained the gain even after 1 week of the exercise. Hence, optimal use of novel T-L methods (open book assignment followed by group tutorials) as revision exercises help in strengthening concepts in Biochemistry in this oft neglected group of low achievers in graduate medical education. © 2016 by The International Union of Biochemistry and Molecular Biology, 44(4):321-325, 2016.

  4. Reasons vs. Causes: Emergence as experienced by the human agent

    OpenAIRE

    Jorion, Paul J

    2007-01-01

    Because they are in constant interaction with each other, human beings are often agents within emergent collective processes. Although they are then acting as particles in a field-type phenomenon, their awareness of what they are part of entails that they hold views about why they’re acting the way they do, these, they call “reasons.” Should physicists dismiss such “reasons” as being illusory causes of events? “Reasons” are actually important explanatory factors of emergent phenomena...

  5. Deductive way of reasoning about the internet AS level topology

    Science.gov (United States)

    Dávid, Szabó; Attila, Kőrösi; József, Bíró; András, Gulyás

    2015-11-01

    Our current understanding about the AS level topology of the Internet is based on measurements and inductive-type models which set up rules describing the behavior (node and edge dynamics) of the individual ASes and generalize the consequences of these individual actions for the complete AS ecosystem using induction. In this paper we suggest a third, deductive approach in which we have premises for the whole AS system and the consequences of these premises are determined through deductive reasoning. We show that such a deductive approach can give complementary insights into the topological properties of the AS graph. While inductive models can mostly reflect high level statistics (e.g., degree distribution, clustering, diameter), deductive reasoning can identify omnipresent subgraphs and peering likelihood. We also propose a model, called YEAS, incorporating our deductive analytical findings that produces topologies contain both traditional and novel metrics for the AS level Internet. Project supported by Ericsson and partially supported by the Hungarian Scientific Research Fund (Grant No. OTKA 108947).

  6. Using optimal combination of teaching-learning methods (open book assignment and group tutorials) as revision exercises to improve learning outcome in low achievers in biochemistry.

    Science.gov (United States)

    Rajappa, Medha; Bobby, Zachariah; Nandeesha, H; Suryapriya, R; Ragul, Anithasri; Yuvaraj, B; Revathy, G; Priyadarssini, M

    2016-07-01

    Graduate medical students of India are taught Biochemistry by didactic lectures and they hardly get any opportunity to clarify their doubts and reinforce the concepts which they learn in these lectures. We used a combination of teaching-learning (T-L) methods (open book assignment followed by group tutorials) to study their efficacy in improving the learning outcome. About 143 graduate medical students were classified into low (75%: group 3, n = 46) achievers, based on their internal assessment marks. After the regular teaching module on the topics "Vitamins and Enzymology", all the students attempted an open book assignment without peer consultation. Then all the students participated in group tutorials. The effects on the groups were evaluated by pre and posttests at the end of each phase, with the same set of MCQs. Gain from group tutorials and overall gain was significantly higher in the low achievers, compared to other groups. High and medium achievers obtained more gain from open book assignment, than group tutorials. The overall gain was significantly higher than the gain obtained from open book assignment or group tutorials, in all three groups. All the three groups retained the gain even after 1 week of the exercise. Hence, optimal use of novel T-L methods (open book assignment followed by group tutorials) as revision exercises help in strengthening concepts in Biochemistry in this oft neglected group of low achievers in graduate medical education. © 2016 by The International Union of Biochemistry and Molecular Biology, 44(4):321-325, 2016. PMID:26891594

  7. Non-Verbal Reasoning Ability and Academic Achievement as Moderators of the Relation between Adverse Life Events and Emotional and Behavioural Problems in Early Adolescence: The Importance of Moderator and Outcome Specificity

    Science.gov (United States)

    Flouri, Eirini; Tzavidis, Nikos

    2011-01-01

    This study was carried out to model the functional form of the effect of contextual risk (number of adverse life events) on emotional and behavioural problems in early adolescence, and to test how intelligence and academic achievement compare as moderators of this effect. The effect of number of adverse life events on emotional and behavioural…

  8. Default logic as a formalism for understanding commonsense reasoning

    OpenAIRE

    Amati, Gianni; Carlucci Aiello, Luigia; Pirri, Fiora

    1996-01-01

    Commonsense reasoning is the reasoning of agents interacting with the real world. Non monotonic reasoning is a well developed research area gathering the logical formalisms that treat commonsense reasoning. One of the best known of such formalisms is Default logic. In this paper we discuss Default logic at both the proof-theoretic and semantics levels and show that Default logic provides a clear and formal framework to understand the logical nature of commonsense reasoning.

  9. Using Literature as a Vehicle to Explore Proportional Reasoning.

    Science.gov (United States)

    Thompson, Denisse R.; Austin, Richard A.; Beckmann, Charlene E.

    The development of proportional reasoning is a major focus of the middle grades curriculum. The challenge for educators is to find contexts that engage students and that facilitate the study of proportional reasoning. This chapter explores proportional thinking with students in grades 3-8 by using a number of books in which the underlying stories…

  10. Proportional reasoning as a key to numeracy across the curriculum

    DEFF Research Database (Denmark)

    Hilton, Annette; Hilton, Geoff

    2013-01-01

    -day workshops in Queensland and four full-day workshops in South Australia). Between workshops, teachers designed and trialled teaching approaches and learning experiences in their classrooms to target their students’ identified proportional reasoning learning needs and capabilities. Data were collected from...... teachers through feedback sessions, surveys, interviews, and practical presentations. Data were collected on student learning outcomes through interviews, diagnostic instruments, and classroom observations. The initial findings revealed that students and teachers had relatively poor proportional reasoning....... Proportional reasoning is the ability to understand, interpret, and solve problems related to situations of proportion, using comparison and relative and multiplicative thinking. It relies on numerous foundational skills including fractional thinking and an understanding of ratio, scale, decimals...

  11. Counter Examples as Starting Points for Reasoning and Sense Making

    Science.gov (United States)

    Yopp, David A.

    2013-01-01

    This article describes a classroom activity with college sophomores in a methods-of-proof course in which students reasoned about absolute value inequalities. The course was designed to meet the needs of both mathematics majors and secondary school mathematics teaching majors early in their college studies. Asked to "fix" a false…

  12. Deductive Way of Reasoning about the Internet AS Level Topology

    OpenAIRE

    Szabó, Dávid; Kőrösi, Attila; Bíró, József; Gulyás, András

    2015-01-01

    Our current understanding about the AS level topology of the Internet is based on measurements and inductive-type models which set up rules describing the behavior (node and edge dynamics) of the individual ASes and generalize the consequences of these individual actions for the complete AS ecosystem using induction. In this paper we suggest a third, deductive approach in which we have premises for the whole AS system and the consequences of these premises are determined through deductive rea...

  13. [Medicolegal considerations about rape as a reason to decriminalize abortion].

    Science.gov (United States)

    González-Wilhelm, Leonardo; Moreno, Leonardo; Carnevali, Raúl

    2016-06-01

    The Chilean senate is discussing a proposal to decriminalize abortion in 3 causals. One of these is when the pregnancy occurs as a result of a rape. To be legally able to perform the abortion in this circumstance, a health care team must confirm the occurrence of the facts constituting the offence. Regardless of the patient’s will, the accusation will be reported to the justice. In our view, in its current status the proposed rule does not consider certain medicolegal and procedural topics. Those flaws may determine in certain scenarios critical problems, such as: a) a wrongful conviction as a consequence of a false allegation of rape; (b) some pregnant due to a rape will not have access to the abortion procedure; (c) some accusations of rape will not be accredited nor criminally sanctioned. Employing a fictional case, we illustrate how those scenarios can actually be seen in practice. We also emphasize the difficulties and limitations that the health care team will encounter if the project is approved under the current conditions. Finally, we encourage the professional societies implicated in the theme to contribute in the legislatorial debate. Therefore, we give a set of proposals aimed to improve the bill before it may be enacted as a law. PMID:27598498

  14. Free choice permission as resource-sensitive reasoning

    Directory of Open Access Journals (Sweden)

    Chris Barker

    2010-09-01

    Full Text Available Free choice permission is a long-standing puzzle in deontic logic and in natural language semantics. It involves what appears to be a conjunctive use of "or": from "You may eat an apple or a pear", we can infer that "You may eat an apple" and that "You may eat a pear" -- though not that "You may eat an apple and a pear". Following Lokhorst (1997, I argue that because permission is a limited resource, a resource-sensitive logic such as Girard's Linear Logic is better suited to modeling permission talk than, say, classical logic. A resource-sensitive approach enables the semantics to track not only that permission has been granted and what sort of permission it is (i.e., permission to eat apples versus permission to eat pears, but also how much permission has been granted, i.e., whether there is enough permission to eat two pieces of fruit or only one. The account here is primarily semantic (as opposed to pragmatic, with no special modes of composition or special pragmatic rules. The paper includes an introduction to Linear Logic. doi:10.3765/sp.3.10 BibTeX info

  15. What Characterises High Achieving Students’ Mathematical Reasoning?

    OpenAIRE

    Haavold, Per Øystein

    2011-01-01

    This study investigates high achieving students’ mathematical reasoning when given an unfamiliar trigonometric equation. The findings indicate that the students’ way of thinking is strongly linked with imitative reasoning and only when they received some form of guidance, were they able to display flexible and creative mathematical reasoning.

  16. Social Intelligence and Academic Achievement as Predictors of Adolescent Popularity

    Science.gov (United States)

    Meijs, Noortje; Cillessen, Antonius H. N.; Scholte, Ron H. J.; Segers, Eliane; Spijkerman, Renske

    2010-01-01

    This study compared the effects of social intelligence and cognitive intelligence, as measured by academic achievement, on adolescent popularity in two school contexts. A distinction was made between sociometric popularity, a measure of acceptance, and perceived popularity, a measure of social dominance. Participants were 512, 14-15 year-old…

  17. Social Intelligence and Academic Achievement as Predictors of Adolescent Popularity

    NARCIS (Netherlands)

    Meijs, N.; Cillessen, A.H.N.; Scholte, R.H.J.; Segers, P.C.J.; Spijkerman, R.

    2010-01-01

    This study compared the effects of social intelligence and cognitive intelligence, as measured by academic achievement, on adolescent popularity in two school contexts. A distinction was made between sociometric popularity, a measure of acceptance, and perceived popularity, a measure of social domin

  18. Parenting Style as a Moderator for Students' Academic Achievement

    Science.gov (United States)

    Ishak, Zahari; Low, Suet Fin; Lau, Poh Li

    2012-01-01

    Parenting styles have always been a crucial factor in influencing all aspects of a person's development. The purpose of this study is to test the structural equation model of academic achievement among the students using parenting styles as a moderator. The sample comprised 493 students from eight schools. Parenting styles are determined using the…

  19. Social Intelligence and Academic Achievement as Predictors of Adolescent Popularity

    OpenAIRE

    Meijs, Noortje; Cillessen, Antonius H. N.; Scholte, Ron H. J.; Segers, Eliane; Spijkerman, Renske

    2008-01-01

    This study compared the effects of social intelligence and cognitive intelligence, as measured by academic achievement, on adolescent popularity in two school contexts. A distinction was made between sociometric popularity, a measure of acceptance, and perceived popularity, a measure of social dominance. Participants were 512, 14–15 year-old adolescents (56% girls, 44% boys) in vocational and college preparatory schools in Northwestern Europe. Perceived popularity was significantly related to...

  20. Parenting Style as a Moderator for Students' Academic Achievement

    Science.gov (United States)

    Ishak, Zahari; Low, Suet Fin; Lau, Poh Li

    2012-08-01

    Parenting styles have always been a crucial factor in influencing all aspects of a person's development. The purpose of this study is to test the structural equation model of academic achievement among the students using parenting styles as a moderator. The sample comprised 493 students from eight schools. Parenting styles are determined using the Parental Authority Questionnaire (Buri in J Pers Assess 57:110-119, 1991). Academic achievement is measured based on the students' performance in the Lower Secondary Assessment. Data were analyzed using structural equation modelling. Results demonstrated that model of authoritative and model of authoritarian fit the data of this study well. Both authoritative and authoritarian parenting styles are the most common practice of the parents. Parenting styles have been found to be a moderator of this study. The results indicated that parenting styles moderated the effect of academic self-concept on academic achievement. The impact of academic self-concept on academic achievement is found to be greater for the authoritative than the authoritarian parenting style.

  1. Cost of renal replacement: how to help as many as possible while keeping expenses reasonable?

    Science.gov (United States)

    Vanholder, Raymond; Lameire, Norbert; Annemans, Lieven; Van Biesen, Wim

    2016-08-01

    The treatment of kidney diseases consumes a substantial amount of the health budget for a relatively small fraction of the overall population. If the nephrological community and society do not develop mechanisms to contain those costs, it will become impossible to continue assuring optimal outcomes and quality of life while treating all patients who need it. In this article, we describe several mechanisms to maintain sustainability of renal replacement therapy. These include (i) encouragement of transplantation after both living and deceased donation; (ii) stimulation of alternative dialysis strategies besides classical hospital haemodialysis, such as home haemodialysis, peritoneal dialysis or self-care and necessitating less reimbursement; (iii) promotion of educational activities guiding the patients towards therapies that are most suited for them; (iv) consideration of one or more of cost containment incentives such as bundling of reimbursement (if not affecting quality of the treatment), timely patient referral, green dialysis, start of dialysis based on clinical necessity rather than renal function parameters and/or prevention of CKD or its progression; (v) strategically planned adaptations to the expected growth of the ageing population in need of renal replacement; (vi) the necessity for support of research in the direction of helping as large as possible patient populations for acceptable costs; and (vii) the need for more patient-centred approaches. We also extend the discussion to the specific situation of kidney diseases in low- and middle-income countries. Finally, we point to the dramatic differences in accessibility and reimbursement of different modalities throughout Europe. We hope that this text will offer a framework for the nephrological community, including patients and nurses, and the concerned policy makers and caregivers on how to continue reaching all patients in need of renal replacement for affordable expenses. PMID:26109485

  2. [Clinical reasoning supportive to a medical service provider as a tool for complaint management: a case study for pragmatic reasoning].

    Science.gov (United States)

    Wessels, B; Seger, W

    2014-12-01

    The process of "clinical reasoning" is exemplified as supportive to the complaint management of the Statutory Medical Health Advisory Board in Lower Saxony, Germany, within the operational division for long-term care insurance. A model case from real life illustrates in detail the hypothetical-deductive approach by Beusheusen and Klemme/Siegmann. Because of the potential area of conflicts between human concern in the case of a long-term care burden and legal requirements, the process was analysed in terms of a pragmatic reasoning. Human resources of the claimant and persons in charge at customer's service were demonstrated as well as political, statutory and institutional determining factors. Concluding self-perception validates the process in the context of evidence-based practice. PMID:25397910

  3. Personal and Pedagogical Interaction Factors as Determinants of Academic Achievement

    OpenAIRE

    Cardoso, Ana Paula; Ferreira, Manuela; Abrantes, José Luís; Seabra, Cláudia; Costa, Cesário

    2011-01-01

    This study intends to relate self-esteem, teacher-student interaction, student-student interaction and learning performance, and its direct and indirect relationships with academic achievement. Using a sample of about 2000 Portuguese high school students, a structural model reveals that low social self-esteem directly and negatively influences teacher-student interaction and studentstudent interaction and also learning performance. Teacher-student interaction directly and positively influence...

  4. Children's Reasoning as Collective Social Action through Problem Solving in Grade 2/3 Science Classrooms

    Science.gov (United States)

    Kim, Mijung

    2016-01-01

    Research on young children's reasoning show the complex relationships of knowledge, theories, and evidence in their decision-making and problem solving. Most of the research on children's reasoning skills has been done in individualized and formal research settings, not collective classroom environments where children often engage in learning and reasoning together to solve classroom problems. This study posits children's reasoning as a collective social activity that can occur in science classrooms. The study examined how children process their reasoning within the context of Grade 2/3 science classrooms and how the process of collectivity emerges from classroom interactions and dialogue between children as they attempt to solve their classroom problems. The study findings suggest that children's reasoning involves active evaluation of theories and evidence through collective problem solving, with consensus being developed through dialogical reasoning.

  5. Critical Thinking: Ethical Reasoning as Essential to Fairminded Critical Thinking, Part III

    Science.gov (United States)

    Paul, Richard; Elder, Linda

    2010-01-01

    In the last two columns the authors introduced the idea of ethical reasoning and discussed its importance to education. They dealt with the problem of egocentric thinking as a barrier to ethical reasoning. And they focused on the importance of distinguishing ethics from other modes of thought with which it is often confused, namely social…

  6. Educating for Civic Engagement: Public Achievement as a Case Study

    Science.gov (United States)

    Costello, Bernadette Christine

    Over the last four decades there is evidence that citizens are less civically engaged, have less trust in each other and governmental institutions, and are less prepared to participate in deliberative and civic processes. This research studies the importance of acquiring deliberative and civic skills and behaviors as an integral part of civic engagement and developing educational and learning strategies to impart those skills and behaviors in an educational environment. This research uses a civic action program called Public Achievement (PA) as a case study to investigate if participating in a civic and deliberative focused program enables participants to continue to use the skills and behaviors learned in PA in non-PA activities. The research study was focused by a literature review of philosophical frameworks, educational history in the United States, and educational theory. The literature review and examples of learning civic skills and behaviors in secondary and higher educational institutions are examined to frame the analysis of PA. Based on the literature review and the design of PA, constructs and a survey instrument were developed to test the hypothesis that students who participate in PA will be more likely to exhibit civic skills and behaviors than students who did not participate in PA. The research was conducted with two schools in rural Missouri, two schools in Minneapolis, Minnesota, and two schools in St. Paul, Minnesota. The study results show that students who participated in PA were not more likely to exhibit civic skills and behaviors, and in many cases, non-PA students exhibited civic skills and behaviors more often. The findings revealed that there are programmatic, organizational, and societal barriers that may impede the effectiveness of PA. The findings suggest that implementation of civic engagement programs may be more effective when the effort is supported and reinforced by and across all parts of the organization, organizational

  7. Public reason as a political ideal: John Rawls’s conception

    Directory of Open Access Journals (Sweden)

    Pavićević Đorđe

    2007-01-01

    Full Text Available The article dealt with Rawlsian idea of public reason as a convergence point of his conception of political liberalism. The idea of public reason is taken as a norm of political justification a as well as a political ideal. Major lines of criticism of the Rawls' conception are also discussed in the article. The conclusion is that is possible to defend major elements of Rawls' conception against criticism along Rawlsian lines of argumentation. The thesis advocated through the text is that it is significant legacy of Rawls' conception of public reason that it discloses limitations of political ideal of liberal democracy. It is argued that one important consequence is that liberalism has to disclaim its own moral superiority in order to make political ideal viable. The other is that any particular society has to find its moral bases in public reason of particular society, that is burdened with peculiar culture and history. .

  8. Exploring individual differences in deductive reasoning as a function of 'autistic'-like traits

    OpenAIRE

    Fugard, Andrew J. B.

    2009-01-01

    From a logical viewpoint, people must reason to as well as from interpretations in deductive reasoning tasks. There are two main interpretative stances (e.g., Stenning & van Lambalgen, 2004, 2005, 2008): credulous, the act of trying to infer the speaker's intended model; and sceptical, an adversarial strategy. A range of contextual factors in uence interpretation, but there are also differences between individuals across situations. Taking an individual differences approach,...

  9. Reconnection production-consumption: change to achieve food and nutritional security, as well as rural development.

    Directory of Open Access Journals (Sweden)

    Shirley Rodríguez-González

    2015-06-01

    Full Text Available The aim of this study was to analyze the importance of changing the conventional food system to achieve food and nutritional security, as well as rural development. This text was divided into three sections. In the first one, the conventional food system and its consequences were characterized, showing the need for a change that seeks the integration of social, environmental, and health dimensions. The second part addressed the interventions related to the food supply system made by the Government, which are fundamental to achieve food and nutrition security, as well as to promote development processes in rural areas. Finally, the experience of Brazil’s National School Feeding Programme was presented. That program links food produced by small producers with the National School Feeding Program, allowing the reconnection of production and consumers through institutional markets. That link created incentives for food and nutrition security of small farmers and, at the same time, improved the availability of higher- quality food for vulnerable populations and promotedeating patterns that allow the preservation of food culture.

  10. Lean Production as Promoter of Thinkers to Achieve Companies' Agility

    Science.gov (United States)

    Alves, Anabela C.; Dinis-Carvalho, Jose; Sousa, Rui M.

    2012-01-01

    Purpose: This paper aims to explore the lean production paradigm as promoter of workers' creativity and thinking potential, and recognize this human potential as a fundamental asset for companies' growth and success, being a major factor to face the disturbing and unpredictable needs of current markets, providing companies with the necessary…

  11. Limited Health Knowledge as a Reason for Non-Use of Four Common Complementary Health Practices.

    Directory of Open Access Journals (Sweden)

    Adam Burke

    Full Text Available Complementary health practices are an important element of health/healthcare seeking behavior among adults in the United States. Reasons for use include medical need, prevention and wellness promotion, and cultural relevance. Survey studies published over the past several decades have provided important information on the use of complementary health practices, such as acupuncture and yoga. A review of the literature, however, reveals an absence of studies looking specifically at who does not use these approaches, and why not.To explore this issue two samples were created using data from the 2007 National Health Interview Survey Complementary and Alternative Medicine supplement. Of particular interest was the relationship between lack of health knowledge, as a reason for non-use, and key independent variables. The first sample was comprised of individuals who had never used any of four common complementary health practices -- acupuncture, chiropractic, natural products, and yoga. The second was a subset of those same non-users who had also reported low back pain, the most frequently cited health concern related to use of complementary therapies.A hypothesized association between lack of health knowledge, lower educational attainment, and other key socioeconomic indicators was supported in the findings. Although it was hypothesized that low back pain would be associated with greater information seeking, regardless of level of education, that hypothesis was not supported.Lack of knowledge was found to affect utilization of common complementary health practices, regardless of the potentially motivating presence of back pain. Disparities in the utilization of complementary medicine, related to educational attainment and other socioeconomic factors, may negatively affect quality of care for many Americans. Creative approaches are needed to help reduce inequities in understanding and improve access to care for underserved populations.

  12. Extremely low density self-assembled InAs/GaAs quantum dots

    Institute of Scientific and Technical Information of China (English)

    Lin Li; Guojun Liu; Zhanguo Li; Mei Li; Xiaohua Wang

    2008-01-01

    The self-assembled InAs/GaAs quantum dots (QDs) with extremely low density of 8×106 cm-2 are achieved using higher growth temperature and lower InAs coverage by low-pressure metal-organic chemical vapour deposition (MOVCD). As a result of micro-photoluminescence (micro-PL), for extremely low density of 8×106 cm-2 InAs QDs in the micro-PL measurements at 10 K, only one emission peak has been achieved. It is believed that the InAs QDs have a good potential to realize single photon sources.

  13. Personality as a moderator of context effects on academic achievement

    NARCIS (Netherlands)

    Hendriks, A.A.J.; Kuyper, H.; Lubbers, M.J; Van der Werf, M.P.C.

    2011-01-01

    We investigated whether personality moderates group influence of classmates on academic achievement and whether these so-called context effects can be attributed to peer pressure. The sample consisted of 2498 students in their first year of Dutch secondary education. The data were analyzed by a two-

  14. School Size as a Factor in Elementary School Achievement.

    Science.gov (United States)

    Alspaugh, John W.; Gao, Rui

    The relationship between elementary school enrollment and fifth-grade achievement was explored using data from a large urban Missouri school district. The district's 39 elementary schools received uniform allocations of resources from the district and used the same instructional materials but varied considerably in K-5 enrollment, socioeconomic…

  15. Personality as a Moderator of Context Effects on Academic Achievement

    Science.gov (United States)

    Hendriks, A. A. Jolijn; Kuyper, Hans; Lubbers, Miranda J.; Van der Werf, Margaretha P. C.

    2011-01-01

    We investigated whether personality moderates group influence of classmates on academic achievement and whether these so-called context effects can be attributed to peer pressure. The sample consisted of 2498 students in their first year of Dutch secondary education. The data were analyzed by a two-level (students within classes) analysis,…

  16. Exploring mental-state reasoning as a social-cognitive mechanism for social loafing in children.

    Science.gov (United States)

    Thompson, Bruce; Thornton, Bill

    2007-04-01

    The authors explored mental-state reasoning ability among 72 preschoolers (ages 3-5 years) as a possible developmental mechanism for the well-known social loafing effect: diminished individual effort in a collaborative task. The authors expected that older children would outperform young children on standard mental-state reasoning tests and that they would display greater social loafing than younger children. In addition, we hypothesized that the ability to infer the mental states of others would be predictive of social loafing, but that the ability to reason about one's own knowledge would not. The authors gave children three standard false-belief tasks and participated in a within-subjects balloon inflation task that they performed both individually and as part of a group. Results indicated that 3-year-olds performed significantly below older preschoolers on mental-state reasoning tasks. Only 4- and 5-year-olds displayed diminished individual effort. Multiple regression analysis indicated that only the ability to reason about others' false beliefs accounted for a significant amount of variance in social loafing; age (in months) and own false-belief reasoning did not. The authors discussed theoretical and pedagogical implications. PMID:17601078

  17. Communicating moral reasoning in medicine as an expression of respect for patients and integrity among professionals.

    Science.gov (United States)

    Kaldjian, Lauris Christopher

    2013-01-01

    The communication of moral reasoning in medicine can be understood as a means of showing respect for patients and colleagues through the giving of moral reasons for actions. This communication is especially important when disagreements arise. While moral reasoning should strive for impartiality, it also needs to acknowledge the individual moral beliefs and values that distinguish each person (moral particularity) and give rise to the challenge of contrasting moral frameworks (moral pluralism). Efforts to communicate moral reasoning should move beyond common approaches to principles-based reasoning in medical ethics by addressing the underlying beliefs and values that define our moral frameworks and guide our interpretations and applications of principles. Communicating about underlying beliefs and values requires a willingness to grapple with challenges of accessibility (the degree to which particular beliefs and values are intelligible between persons) and translatability (the degree to which particular beliefs and values can be transposed from one moral framework to another) as words and concepts are used to communicate beliefs and values. Moral dialogues between professionals and patients and among professionals themselves need to be handled carefully, and sometimes these dialogues invite reference to underlying beliefs and values. When professionals choose to articulate such beliefs and values, they can do so as an expression of respectful patient care and collaboration and as a means of promoting their own moral integrity by signaling the need for consistency between their own beliefs, words and actions.

  18. An Analysis of High School Mathematics Achievement and English Language Arts Achievement as Predictors of Science Achievement

    Science.gov (United States)

    Edwards, Anthony C.

    2012-01-01

    Science assessments require students to read and comprehend questions and to solve mathematical problems. The purpose of this study is to determine whether the following variables can be used to predict science achievement: English language arts achievement, mathematics achievement, socioeconomic status (SES), limited English proficiency (LEP)…

  19. Tele-centres as a way of achieving universal access

    DEFF Research Database (Denmark)

    Falch, Morten; Anyimadu, Amos

    2003-01-01

    The success of tele-centres in Ghana is discussed. The tele-centres offer a low cost opportunity to empower local communities in developed and developing countries to meet the challenges of the information society. The tele-centres can also contribute more directly to the supply of non-commercial...

  20. EMS as a basis of sustainable technological process achievement

    Directory of Open Access Journals (Sweden)

    R. Nowosielski

    2008-08-01

    Full Text Available Purpose: The paper presents main principles of environmental management systems ISO 14001 and EMAS. Thanks to EMS organizations can improve theirs activity especially through environmental modernization introducing to realized technological processes.Design/methodology/approach: Implementation of EMS provides organizations many benefits: increasing the efficient use of resources; waste reducing; demonstrate a good corporate image; building awareness of environmental concern among employees; gaining a better understanding of the environmental impacts of business activities and increase profit, improving environmental performance.Findings: In this article structure of ISO 14001 and EMAS were presented. Moreover the analysis and the modernization of the oil filter casings production process were showed.Research limitations/implications: Both ISO 14001 and EMAS II application all organizational units, especially industrial enterprises. The EMS requirements make possible technological processes continuous improvement especially in environment protection sphere.Practical implications: Formalized environmental management systems ISO 14001 and EMAS help enterprises in accommodation to the growing requirements of the environment protection prescriptions.Originality/value: The only one possibility of the environment protection is implementation and continuous improvement of EMS by every organization. It can be achieved through technological processes improvement.

  1. Women's rights advocates achieve victories as UN conference concludes.

    Science.gov (United States)

    1995-09-29

    On September 15, 1995, government delegations finished the Platform for Action of the United Nations Fourth World Conference on Women in Beijing, China. In this historic document, individual governments and the international community committed themselves to the advancement of women worldwide. Human rights issues (violence against women and female children, and reproductive freedom and health) were discussed and affirmed. Paragraph 2 of the human rights section states that "the human rights of women and the girl child are an inalienable, integral and indivisible part of universal human rights." Paragraph 9 adds "full realization of all human rights and fundamental freedoms of all women is essential for the empowerment of women." Acknowledging "the significance of national and regional particularities and various historical, cultural and religious backgrounds," the document still calls for "states, regardless of their political, economic and cultural systems, to promote and protect all human rights and fundamental freedoms." The human rights section "reaffirms that [reproductive rights] rest on the recognition of the basic right of all couples and individuals to decide freely and responsibly the number, spacing, and timing of their children and to have the information and means to do so, and the right to attain the highest standard of sexual and reproductive health. It also includes their right to make decisions concerning reproduction free of discrimination, coercion and violence, as expressed in human rights documents." The platform recognizes violence against women and girls in all societies (physical, psychological, and sexual abuse that includes murder; systematic rape; forced pregnancy, sterilization, contraception, and abortion; female infanticide; battering; and trafficking in women that is perpetrated by state and nonstate actors). The section on women and armed conflict declares that "rape in the conduct of armed conflict constitutes a war crime and under

  2. Anomalies as a Catalyst for Middle School Students' Knowledge Construction and Scientific Reasoning during Science Inquiry.

    Science.gov (United States)

    Echevarria, Marissa

    2003-01-01

    Knowledge construction and scientific reasoning were examined during a unit in genetics, in which anomalies were used as a catalyst for student learning. Students used genetics simulation software to develop hypotheses and run tests of fruit fly crosses to develop mental models of simple dominance trait transmission. Instruction was intended to…

  3. Psychological Trauma as a Reason for Computer Game Addiction among Adolescents

    Science.gov (United States)

    Oskenbay, Fariza; Tolegenova, Aliya; Kalymbetova, Elmira; Chung, Man Cheung; Faizullina, Aida; Jakupov, Maksat

    2016-01-01

    This study explores psychological trauma as a reason for computer game addiction among adolescents. The findings of this study show that there is a connection between psychological trauma and computer game addiction. Some psychologists note that the main cause of any type of addiction derives from psychological trauma, and that finding such…

  4. Reasoning with Limited Resources: Active Logics Expressed as Labeled Deductive Systems

    OpenAIRE

    Asker, Mikael; Malec, Jacek

    2005-01-01

    Reasoning with limited computational resources (such as time or memory) is an important problem, in particular in knowledge-intensive embedded systems. Classical logic is usually considered inappropriate for this purpose as no guarantees regarding deadlines can be made. One of the moreinteresting approaches to address this problem is built around the concept of active logics. Although a step in the right direction, active logics are just a preliminary attempt towards finding an acceptable sol...

  5. Management accountants as business partners : An empirical analysis based on the theory of reasoned action

    OpenAIRE

    Wolf, Sebastian; Weißenberger, Barbara E.; Kabst, Rüdiger; Wehner, Sebastian

    2010-01-01

    Business practice and literature frequently advocate more business oriented roles for management accountants. The aim of this study is to examine reasons for management accountants to act as business partners and to analyze corresponding performance effects. More specifically, two research questions are investigated: (i) why do management accountants act as business partners, and (ii) are business oriented management accountants beneficial to organizations? To answer these research questio...

  6. Adults learning Finnish as a foreign language : role of support, emotions and reasons connected with learning

    OpenAIRE

    MacKenzie, Ashley

    2015-01-01

    The purpose of this research study was to examine adults learning Finnish as a foreign language while striving to understand the reasons behind their decisions to do so, the support that was individually offered to the participants, how they felt throughout the learning process, and whether or not they found themselves to be self-reliant learners, as per Knowles’ andragogy theory. This study set out to examine adult language learners participating in the language and integration program at Pa...

  7. Of Pigs and Men: Understanding Students' Reasoning About the Use of Pigs as Donors for Xenotransplantation

    Science.gov (United States)

    Lindahl, Mats Gunnar

    2010-09-01

    Two important roles of education are to provide students with knowledge for their democratic participation in society and to provide knowledge for a future profession. In science education, students encounter values that may be in conflict with their worldview. Such conflicts may, for example, lead to constructive reflections as well as rejection of scientific knowledge and technology. Students’ ways of reasoning are important starting points for discussing problematic issues and may be crucial for constructive dialogues in the classroom. This study investigates students’ reasoning about conflicting values concerning the human-animal relationship exemplified by the use of genetically modified pigs as organ donors for xenotransplantation. Students’ reasoning is analyzed using Giddens’ concepts of disembedded and embedded practices in parallel with moral philosophical theories in a framework based on human-animal relationships. Thirteen students were interviewed and their stances categorized. Kantian deontological and classical utilitarian ethics were found within the patronage and the partnership models. These students appreciated expert knowledge but those using the partnership model could not accept xenotransplantation if pigs were to be killed. Students using care ethics did not appreciate expert knowledge since it threatened naturalness. The results suggest that stances against the use of scientific knowledge are more problematic than knowledge per se, and that conflicting stances have similarities that present opportunities for understanding and development of students’ argumentation skills for future participation in societal discourse on utilizing expert knowledge. Furthermore it is argued that science education could benefit from a higher awareness of the presence of different morals.

  8. Electronic books as low vision aids

    OpenAIRE

    Crossland, Michael; Macedo, António Filipe; Rubin, G S

    2010-01-01

    Every year, around 34 000 people in England and Wales are newly registered as sight impaired or severely sight impaired, the majority of whom have some residual vision.1 In order to read books, people with low vision will generally rely on large print books and supplementary optical2 or electronic3 magnifiers. Only about 1.5% of the approximately two million books currently in print are available in large print format.4 Recently, several electronic book readers have become commercially av...

  9. Teacher Trainers as Action Researchers: Scrutinizing the Reasons for Student Failure

    Science.gov (United States)

    Gürsoy, Emel; Çelik Korkmaz, Sule

    2015-01-01

    This action research aims to identify the teacher trainees' attributions for their failure, their locus of control and their achievement goals as a result of high failure rate in "Teaching English to Young Learners" course at a large state university in Turkey. For this purpose, qualitative and quantitative data were gathered via an…

  10. Three fuzzy reasoning models as a decision suport aid, to find an electrical energy tariff

    Directory of Open Access Journals (Sweden)

    Daniela GHINITA

    2005-12-01

    Full Text Available This contribution is a laboratory-work developed as an example of approximate (fuzzy reasoning for students, possible to be used as a decision – support to estimate an electrical energy (EE price for consumers. The three fuzzy tariff estimation models that are developed, integrate not only the S.C Electrica S.A.-single-supplier rate position, but and some (social constraints/ compulsions of National Authority of Settlements from Energy (NASE beginning with 1999, in this transition period from Romania. Although is possible, the paper not refer to a partial-price concrete case (internal tariff used in certain year, production price, transport price, distribution price, spot price, or an external price to be sold electrical energy, etc. This “laboratory-work-paper” shows how, by changing the parameters of S.C Electrica S.A. and NASE, it is possible to can perform sensitivity tests on the tariff function model, until can obtain an acceptable and true price. In this aim, the three fuzzy models use different rules for pricing: conservative, aggressive, and different order of words concerning the rules respectively, finally doing a comparation among prices and models. The paper not finished all fuzzy possibilities (rules which can influences the expected value of a some EE tariff but, with certitude, can create a discussion base, about the way of approximate/ fuzzy reasoning, as a modality to find and to refine an EE price.

  11. Learning about causes from people and about people as causes: probabilistic models and social causal reasoning.

    Science.gov (United States)

    Buchsbaum, Daphna; Seiver, Elizabeth; Bridgers, Sophie; Gopnik, Alison

    2012-01-01

    A major challenge children face is uncovering the causal structure of the world around them. Previous research on children's causal inference has demonstrated their ability to learn about causal relationships in the physical environment using probabilistic evidence. However, children must also learn about causal relationships in the social environment, including discovering the causes of other people's behavior, and understanding the causal relationships between others' goal-directed actions and the outcomes of those actions. In this chapter, we argue that social reasoning and causal reasoning are deeply linked, both in the real world and in children's minds. Children use both types of information together and in fact reason about both physical and social causation in fundamentally similar ways. We suggest that children jointly construct and update causal theories about their social and physical environment and that this process is best captured by probabilistic models of cognition. We first present studies showing that adults are able to jointly infer causal structure and human action structure from videos of unsegmented human motion. Next, we describe how children use social information to make inferences about physical causes. We show that the pedagogical nature of a demonstrator influences children's choices of which actions to imitate from within a causal sequence and that this social information interacts with statistical causal evidence. We then discuss how children combine evidence from an informant's testimony and expressed confidence with evidence from their own causal observations to infer the efficacy of different potential causes. We also discuss how children use these same causal observations to make inferences about the knowledge state of the social informant. Finally, we suggest that psychological causation and attribution are part of the same causal system as physical causation. We present evidence that just as children use covariation between

  12. Semantic Matchmaking as Non-Monotonic Reasoning: A Description Logic Approach

    CERN Document Server

    Di Noia, T; Donini, F M; 10.1613/jair.2153

    2011-01-01

    Matchmaking arises when supply and demand meet in an electronic marketplace, or when agents search for a web service to perform some task, or even when recruiting agencies match curricula and job profiles. In such open environments, the objective of a matchmaking process is to discover best available offers to a given request. We address the problem of matchmaking from a knowledge representation perspective, with a formalization based on Description Logics. We devise Concept Abduction and Concept Contraction as non-monotonic inferences in Description Logics suitable for modeling matchmaking in a logical framework, and prove some related complexity results. We also present reasonable algorithms for semantic matchmaking based on the devised inferences, and prove that they obey to some commonsense properties. Finally, we report on the implementation of the proposed matchmaking framework, which has been used both as a mediator in e-marketplaces and for semantic web services discovery.

  13. Evolution as represented through argumentation: A qualitative study on reasoning and argumentation in high school biology teaching practices

    Science.gov (United States)

    Yalcinoglu, Pelin

    This study aimed to explore high school biology teachers' epistemological criteria and their attention to reasoning and argumentation within their instructional practices. This study investigated: (1) what epistemological criteria do high school biology teachers use when justifying the validity of conclusions, (2) what is the frequency of the explicit use of reasoning and argumentation, if any, in high school biology teachers' instructional practices, and to what extend are reasoning and argumentation skills reflected, if at all, in high school biology teachers' modes of assessment. Three different data collection methods were employed in this study; face-to-face interviews, classroom observations, and document collections. Teachers' epistemological criteria were investigated to provide insight about their reasoning structures. This investigation was made possible by having teachers provide an argument about the validity of hypothetical conclusions drawn by the students based on two different scenarios related to evolution. Toulmin's Argument Pattern used to create rubric to analyze high school biology teachers' levels of reasoning through argumentation. Results of the data analysis suggested following findings. First, high school biology teachers participated in this study presented variety of epistemological criteria which were presented as high, moderate and low levels of reasoning through the argumentations. Second, elements of Toulmin's Argument Pattern were visible in the participants teaching practices, however students were not explicitly introduced to a well structured argument in those classrooms. High level of reasoning was not evident in the instructional practices of the observed teachers. High school biology classrooms which were observed in this study do not provide opportunities for students to practice high level of reasoning or improve their argumentation skills. Third, Interview Protocols designed for this study were found useful to identify the

  14. Islamic Modernists and Discourse on Reason as a Reconciliatory Argument between Islam and the Western Enlightenment

    Directory of Open Access Journals (Sweden)

    ASMAHAN SALLAH

    2015-06-01

    Full Text Available This article examines the debates on the relationship between Islam and reason during the nineteenth century and early twentieth century. It argues that these debates were transnational but were largely influenced by similar debates in the Western tradition. It also affirms that modernists used discourse on reason to reconcile Islam with Western Enlightenment. The article illustrates the various mechanisms which Islamic modernists implemented to facilitate such reconciliation. These mechanisms include rationalization of miracles, contesting the concept of prophethood, and rejecting the scholarship of Islamic jurisprudence and theology. Based on writings by several Islamic modernists, such as their biographies of Prophet Muhammad, Quran commentaries, and magazine articles in different Islamic countries, I ascribe these mechanisms to a gap between logic and experimental thought, a gap which seeped into the mind of Islamic modernists under the influence of Western contemporary thinkers. While this discourse claims compatibility between Islam and Western Enlightenment, it also resists the binary of the sacred and the secular, a major legacy of the Western Enlightenment.

  15. Problems with change in R2 as applied to theory of reasoned action research.

    Science.gov (United States)

    Trafimow, David

    2004-12-01

    The paradigm of choice for theory of reasoned action research seems to depend largely on the notion of change in variance accounted for (DeltaR2) as new independent variables are added to a multiple regression equation. If adding a particular independent variable of interest increases the variance in the dependent variable that can be accounted for by the list of independent variables, then the research is deemed to be 'successful', and the researcher is considered to have made a convincing argument about the importance of the new variable. In contrast to this trend, I present arguments that suggest serious problems with the paradigm, and conclude that studies on attitude-behaviour relations would advance the field of psychology to a far greater extent if researchers abandoned it.

  16. The Achievement Motivation-Performance Relationship as Moderated by Sex-Role Attitudes

    Science.gov (United States)

    Thurber, Steven

    1976-01-01

    The moderating effect of sex-role attitudes in relation to the predictive validity of Mehrabian's achievement tendency scale for females is examined. The scale predicts better for academic achievement with females classified as non-traditional in sex-role orientation, and in social achievement for females classified as traditional. (Author/JKS)

  17. THE PRINCIPLE OF REASONED SHAPE FORMING AS A BASIS FOR PLASTIC ADEQUACY OF DESIGN OBJECTS

    Directory of Open Access Journals (Sweden)

    Vitaly Vasilyevich Miroshnikov

    2015-01-01

    Full Text Available The article highlights the basic approaches to configuring the form in design. The authors analyze the main strategies of shape formation in modern design practices. The novelty of the subject is that the analysis is carried out in the context of the adequacy of the design of plastic objects. The essence of the problems outlined by the authors is inconsistency between the object’s semantics and its external form resulted from incorrect practices of shape formation. Consideration of strategies and tactics of configuration of forms is based on comparison of two principles of shape formation - intuitive and discursive. The aim of the authors is to identify the reasons and structural specificity of intuitive and discursive practices of shape formation in design and to show the priority of the discursive approach. Attention of the authors is focused on the differences of search algorithms and results of shaping which are characteristic for the principles under consideration. The arguments cited in the article determine the discursive strategy of form configuration as the most correct and efficient in terms of design engineering. In the process of analyzing the basic algorithms of shape formation, of topical importance is the concept of legitimacy of form as a definition of the most appropriate process and a results of the project research. The article gives the interpretation of legitimacy in terms of the project practices and design - education.

  18. Feasibility of Self-Reflection as a Tool to Balance Clinical Reasoning Strategies

    Science.gov (United States)

    Sibbald, Matthew; de Bruin, Anique B. H.

    2012-01-01

    Clinicians are believed to use two predominant reasoning strategies: system 1 based pattern recognition, and system 2 based analytical reasoning. Balancing these cognitive reasoning strategies is widely believed to reduce diagnostic error. However, clinicians approach different problems with different reasoning strategies. This study explores…

  19. `Grasp of Practice' as a Reasoning Resource for Inquiry and Nature of Science Understanding

    Science.gov (United States)

    Ford, Michael

    2008-02-01

    This article articulates how a ‘grasp of practice’ serves as a reasoning resource for inquiry and citizenship abilities associated with nature of science (NOS) understanding. Theoretically, this resource is elaborated through an overlapping concern with ‘practice’ in two literatures, science studies and psychology of learning, bringing attention to two key roles in scientific practice, Critiquers and Constructors of claims. Empirically, this resource is made plausible by the results of an expert-novice study and a classroom study. In the expert-novice study, reactions of scientists and laypeople to science-related claims in the popular media were contrasted, underlining the appropriate ways scientists tend to Critique such claims. In the classroom study, sixth-grade students engaged in a 2-week ramp experiment, experiencing first hand the roles of Critiquers and Constructors of claims, and were subsequently assessed with a novel experimental task. Performances suggest that students had attained a grasp of practice, going well beyond mere execution of methods or procedures. These results challenge a common assumption that declarative knowledge best characterizes learning targets for supporting inquiry and NOS understanding.

  20. The Theory of Reasoned Action as Parallel Constraint Satisfaction: Towards a Dynamic Computational Model of Health Behavior

    OpenAIRE

    Orr, Mark G; Thrush, Roxanne; Plaut, David C.

    2013-01-01

    The reasoned action approach, although ubiquitous in health behavior theory (e.g., Theory of Reasoned Action/Planned Behavior), does not adequately address two key dynamical aspects of health behavior: learning and the effect of immediate social context (i.e., social influence). To remedy this, we put forth a computational implementation of the Theory of Reasoned Action (TRA) using artificial-neural networks. Our model re-conceptualized behavioral intention as arising from a dynamic constrain...

  1. "As Long as You Work Hard, You Can Achieve Your Goals" : Hungarian Immigrants on the American Dream

    OpenAIRE

    Orsolya Kolozsvari

    2012-01-01

    Immigrants to the United States frequently perceive America as the land of endless opportunities and prosperity, and this perception is very frequently a propelling force in the decision for immigration. Through 20 in-depth interviews with middle-class Hungarians who live in the United States I will discuss how immigration to the United States has influenced the perceptions of these Hungarians of opportunities in the United States. I will also highlight how reasons for immigration and percept...

  2. Low Wages as Occupational Health Hazards.

    Science.gov (United States)

    Leigh, J Paul; De Vogli, Roberto

    2016-05-01

    The history of occupational medicine has been characterized by ever-widening recognition of hazards, from fires in 1911 to asbestos in the 1960s, to job strain in the 1990s. In this essay, we argue for broadening the recognition further to include low wages. We first review possible mechanisms explaining the effects of wages on health or health behaviors. Mechanisms involve self-esteem, job satisfaction, deprivation, social rank, the "full" price of bad health, patience, and the ability to purchase health-producing goods and services. Second, we discuss empirical studies that rely on large, typically national, data sets and statistical models that use either instrumental variables or natural experiments and also account for other family income. Finally, we draw implications for laws governing minimum wages and labor unions. PMID:27158950

  3. Foreign Language Learning Aptitudes, Attitudes, Attributions, and Achievement of Postsecondary Students Identified as Gifted

    Science.gov (United States)

    Bain, Sherry K.; McCallum, R. Steve; Bell, Sherry Mee; Cochran, Jeff L.; Sawyer, Stephani Choate

    2010-01-01

    We investigated the aptitudes, attitudes, attributions, and achievement of undergraduates identified as gifted who were taking a beginning Spanish course, and compared these characteristics to undergraduates in the same cohort group who had not been identified as gifted. There were differences in the aptitudes, attitudes, and achievement of…

  4. Using Garlic As A Far-Transfer Problem of Proportional And Probabilistic Reasoning

    CERN Document Server

    Moore, N T

    2008-01-01

    The work describes a general problem, which emphasizes proportional reasoning and probabilistic reasoning skills in the context of planting garlic in a backyard garden. Along with practicing these reasoning skills in a context far-removed from the standard high school or college curriculum, our solution involves the development of a few relatively sophisticated statistical concepts, specifically histograms and confidence intervals.

  5. Building on the Enriched Hierarchical Model of Achievement Motivation: Autonomous and Controlling Reasons Underlying Mastery Goals

    Directory of Open Access Journals (Sweden)

    Aikaterini Michou

    2016-07-01

    Full Text Available Two motivational theories – the Achievement Goal Theory and Self-Determination Theory – have recently been combined to explain students’ motivation, making it possible to study the “what” and the “why” of learners’ achievement strivings. The present study built on this approach by (a investigating whether the distinction between autonomous or volitional and controlling or pressuring reasons can be meaningfully applied to the adoption of mastery-avoidance goals, (b investigating the concurrent and prospective relations between mastery-avoidance goals and their underlying reasons and learning strategies when mastery-approach goals and their underlying reasons were also considered, and by (c incorporating psychological need experiences as an explanatory variable in the relation between achievement motives (i.e., the motive to succeed and motive to avoid failure and both mastery goals and their underlying reasons. In two Turkish university students samples ('N' = 226, 'Mage '= 22.36; 'N' = 331, 'Mage '= 19.5, autonomous and controlling reasons appeared applicable to mastery-avoidance goals and regression and path analysis further showed that mastery-avoidance goals and their underlying autonomous reasons fail to predicted learning strategies over and above the pursuit of mastery-approach goals and their underlying reasons. Finally, need experiences were established as mediators between achievement motives and both mastery goals and their underlying reasons.

  6. Fluid intellingence and spatial reasoning as predictors of pilot training performance in the South African Air Force (SAAF

    Directory of Open Access Journals (Sweden)

    François de Kock

    2009-04-01

    Full Text Available Pilot selection is a form of high-stakes selection due to the massive costs of training, high trainee ability requirements and costly repercussions of poor selection decisions. This criterion-related validation study investigated the predictive ability of fluid intelligence and spatial reasoning in predicting three criteria of pilot training performance, using an accumulated sample of South African Air Force pilots (N = 108. Hierarchical multiple regression analyses with training grade achieved as criterion were performed for each of the phases of training, namely practical flight training, ground school training, and officers’ formative training. Multiple correlations of 0.35 (p < 0.01, 0.20 (p > 0.05 and 0.23 (p > 0.05 were obtained for flight, ground school and formative training results, respectively. Spatial ability had incremental validity over fluid intelligence for predicting flight training performance.

  7. The Visual Aural Digit Span Test and Bender Gestalt Test as Predictors of Wide Range Achievement Test-Revised Scores.

    Science.gov (United States)

    Smith, Teresa C.; Smith, Billy L.

    1988-01-01

    Examined Visual Aural Digit Span Test (VADS) and Bender-Gestalt (BG) scores as predictors of Wide Range Achievement Test-Revised (WRAT-R) scores among 115 elementary school students referred for low academic achievement. Divided children into three age groups. Results suggest BG and VADS Test can be effective screening devices for young children…

  8. A New Look at the Old Problem of a Reasonable Expectation: The Reasonableness of Repeated Renewals of Fixed Term Contracts as Opposed to Indefinite Employment

    Directory of Open Access Journals (Sweden)

    E Gericke

    2011-04-01

    Full Text Available In South Africa, the Labour Relations Act 66 of 1995 (LRA regulates and protects the position of the employee who reasonably expects that a fixed-term contract will be renewed on the same or similar terms while the employer only offered to renew the contract on less favourable terms or in some instances was not prepared torenew the fixed-term contract at all. The LRA regards the latter conduct as a dismissal, as long as the employee can prove that the employer was responsible for creating the reasonable expectation of contractual renewal. In contrast to this position, the LRA does not regulate or protect the position of the employee whose fixed-term contract was repeatedly renewed on the same, similar or even improved terms, while the employer was in a position to offer the employee indefinite employment. The employer may even have created a reasonable expectation that repeated renewals would result in permanent employment. The exploitation and abuse of the fixed-term contract to the extent that an employee is deprived of employment security and the benefits linked to an employment relationship of indefinite duration have prompted a comparative investigation into this particular field of law.

  9. Low and high achievers in math

    DEFF Research Database (Denmark)

    Overgaard, Steffen; Tonnesen, Pia Beck; Weng, Peter;

    2015-01-01

    In this session we will present the results of the preliminary analysis of the qualitative and quantitative data, which can be used to enhance the teaching of low and high mathematics achievers so as to increase their mathematical knowledge and confidence.......In this session we will present the results of the preliminary analysis of the qualitative and quantitative data, which can be used to enhance the teaching of low and high mathematics achievers so as to increase their mathematical knowledge and confidence....

  10. Children's Reasoning as Collective Social Action through Problem Solving in Grade 2/3 Science Classrooms

    Science.gov (United States)

    Kim, Mijung

    2016-01-01

    Research on young children's reasoning show the complex relationships of knowledge, theories, and evidence in their decision-making and problem solving. Most of the research on children's reasoning skills has been done in individualized and formal research settings, not collective classroom environments where children often engage in learning and…

  11. Retrocausal Effects as a Consequence of Quantum Mechanics Refined to Accommodate the Principle of Sufficient Reason

    Energy Technology Data Exchange (ETDEWEB)

    Stapp, Henry P.

    2011-05-10

    The principle of sufficient reason asserts that anything that happens does so for a reason: no definite state of affairs can come into being unless there is a sufficient reason why that particular thing should happen. This principle is usually attributed to Leibniz, although the first recorded Western philosopher to use it was Anaximander of Miletus. The demand that nature be rational, in the sense that it be compatible with the principle of sufficient reason, conflicts with a basic feature of contemporary orthodox physical theory, namely the notion that nature's response to the probing action of an observer is determined by pure chance, and hence on the basis of absolutely no reason at all. This appeal to pure chance can be deemed to have no rational fundamental place in reason-based Western science. It is argued here, on the basis of the other basic principles of quantum physics, that in a world that conforms to the principle of sufficient reason, the usual quantum statistical rules will naturally emerge at the pragmatic level, in cases where the reason behind nature's choice of response is unknown, but that the usual statistics can become biased in an empirically manifest way when the reason for the choice is empirically identifiable. It is shown here that if the statistical laws of quantum mechanics were to be biased in this way then the basically forward-in-time unfolding of empirical reality described by orthodox quantum mechanics would generate the appearances of backward-time-effects of the kind that have been reported in the scientific literature.

  12. Retrocausal Effects as a Consequence of Quantum Mechanics Refined to Accommodate the Principle of Sufficient Reason

    International Nuclear Information System (INIS)

    The principle of sufficient reason asserts that anything that happens does so for a reason: no definite state of affairs can come into being unless there is a sufficient reason why that particular thing should happen. This principle is usually attributed to Leibniz, although the first recorded Western philosopher to use it was Anaximander of Miletus. The demand that nature be rational, in the sense that it be compatible with the principle of sufficient reason, conflicts with a basic feature of contemporary orthodox physical theory, namely the notion that nature's response to the probing action of an observer is determined by pure chance, and hence on the basis of absolutely no reason at all. This appeal to pure chance can be deemed to have no rational fundamental place in reason-based Western science. It is argued here, on the basis of the other basic principles of quantum physics, that in a world that conforms to the principle of sufficient reason, the usual quantum statistical rules will naturally emerge at the pragmatic level, in cases where the reason behind nature's choice of response is unknown, but that the usual statistics can become biased in an empirically manifest way when the reason for the choice is empirically identifiable. It is shown here that if the statistical laws of quantum mechanics were to be biased in this way then the basically forward-in-time unfolding of empirical reality described by orthodox quantum mechanics would generate the appearances of backward-time-effects of the kind that have been reported in the scientific literature.

  13. Hermeneutics of reason: the principle of common rationality as premise of understanding the Other(s)

    OpenAIRE

    Mihai Stelian Rusu

    2013-01-01

    The central argument defended in this paper is made up of two interconnected statements: i) that a minimally defined rationality is an anthropological constant, being shared by all conceivable human cultures; and ii) that this “commonality of reason” constitutes the basis on which inter-cultural understanding is possible. In proving the first thesis (the universality of reason), the paper contrasts Western thought, epitomized in scientific reason, with non-Western thinking patterns, expressed...

  14. Theories of Reasoned Action and Planned Behavior as Models of Condom Use: A Meta-Analysis

    OpenAIRE

    Albarracín, Dolores; Johnson, Blair T.; Fishbein, Martin; Muellerleile, Paige A.

    2001-01-01

    To examine how well the theories of reasoned action and planned behavior predict condom use, the authors synthesized 96 data sets (N = 22,594) containing associations between the models’ key variables. Consistent with the theory of reasoned action’s predictions, (a) condom use was related to intentions (weighted mean r. = .45), (b) intentions were based on attitudes (r. = .58) and subjective norms (r. = .39), and (c) attitudes were associated with behavioral beliefs (r. = .56) and norms were ...

  15. Spatial ability as a predictor of math achievement: the importance of sex and handedness patterns.

    Science.gov (United States)

    Casey, M B; Pezaris, E; Nuttall, R L

    1992-01-01

    In accordance with major theories of handedness and brain organization, differential predictors for math achievement were found as a function of sex and handedness subgroups among eighth graders. Although there was no difference in absolute levels of performance as a function of either sex or handedness, predictive structures did differ. Regression analyses showed that spatial ability predicts math achievement for: (1) girls with anomalous dominance (non-right-handers and right-handers with non-right-handed relatives), and (2) all boys (independent of handedness group). In contrast, for the standard dominance girls who are right-handed with all right-handed relatives (considered strongly left-hemisphere dominant for language), spatial ability did not predict for math achievement. These findings occurred, even when scholastic aptitude and verbal achievement factors were controlled. It was concluded that further studies of sex differences in math achievement should consider subgroup differences within the sexes, based on handedness patterns.

  16. Reasons and Outcomes of Work-Family Conflict and Work Alienation as one of Its Outcomes

    Directory of Open Access Journals (Sweden)

    Seyed Abdolhossein Nabavi

    2014-11-01

    research expectations of social support role and its effects on work alienation. It appears that the effectiveness of social support can influence work alienation through expectations of work role, work ambiguity and work- family conflict. In other words, expectations of work role and work role ambiguity are effective on work alienation through family-work conflict. It is necessary to mention that there is a significant and reverse relationship between work control and work alienation. Organizational managers can have happy and satisfied personnel, who give their effective performance and show interest, loyalty and commitment to the organization, if they help them to make a balance between work and life. As the results indicate, establishing a balance between work and family is of great value. Achieving this end requires that managers select an approach in which employees' and organization’s interests could be synchronously considered. They should abandon traditional attitudes on the relationship between work and life. Therefore, in order to prevent the negative consequences of work-family conflict, which are sometimes irreparable, it is recommended that employees become familiar with scientific management of conflict, and be supported comprehensively by their family members and coworkers. Thus, they will have more freedom and flexibility, and minimum conflict will be seen in their work and family programs. On the other hand, it is necessary to improve and reform occupational laws and rules.

  17. Learning strategies and general cognitive ability as predictors of gender- specific academic achievement

    OpenAIRE

    Ruffing, Stephanie; Wach, F.-Sophie; Spinath, Frank M.; Brünken, Roland; Karbach, Julia

    2015-01-01

    Recent research has revealed that learning behavior is associated with academic achievement at the college level, but the impact of specific learning strategies on academic success as well as gender differences therein are still not clear. Therefore, the aim of this study was to investigate gender differences in the incremental contribution of learning strategies over general cognitive ability in the prediction of academic achievement. The relationship between these variables was examined by ...

  18. Intelligence and Metacognition as Predictors of Foreign Language Achievement: A Structural Equation Modeling Approach

    Science.gov (United States)

    Pishghadam, Reza; Khajavy, Gholam Hassan

    2013-01-01

    This study examined the role of metacognition and intelligence in foreign language achievement on a sample of 143 Iranian English as a Foreign Language (EFL) learners. Participants completed Raven's Advanced Progressive Matrices as a measure of intelligence, and Metacognitive Awareness Inventory as a measure of metacognition. Learners' scores at…

  19. Protection as care: moral reasoning and moral orientation among ethnically and socioeconomically diverse older women.

    Science.gov (United States)

    Dakin, Emily

    2014-01-01

    This study examined moral reasoning among ethnically and socioeconomically diverse older women based on the care and justice moral orientations reflecting theoretical frameworks developed by Carol Gilligan and Lawrence Kohlberg, respectively. A major gap in this area of research and theory development has been the lack of examination of moral reasoning in later life. This study addressed this gap by assessing socioeconomically and ethnically diverse older women's reasoning in response to ethical dilemmas showing conflict between autonomy, representative of Kohlberg's justice orientation, and protection, representative of Gilligan's care orientation. The dilemmas used in this study came from adult protective services (APS), the U.S. system that investigates and intervenes in cases of elder abuse and neglect. Subjects were 88 African American, Latina, and Caucasian women age 60 or over from varying socioeconomic status backgrounds who participated in eight focus groups. Overall, participants favored protection over autonomy in responding to the case scenarios. Their reasoning in responding to these dilemmas reflected an ethic of care and responsibility and a recognition of the limitations of autonomy. This reasoning is highly consistent with the care orientation. Variations in the overall ethic of care and responsibility based on ethnicity and SES also are discussed.

  20. Hermeneutics of reason: the principle of common rationality as premise of understanding the Other(s

    Directory of Open Access Journals (Sweden)

    Mihai Stelian Rusu

    2013-06-01

    Full Text Available The central argument defended in this paper is made up of two interconnected statements: i that a minimally defined rationality is an anthropological constant, being shared by all conceivable human cultures; and ii that this “commonality of reason” constitutes the basis on which inter-cultural understanding is possible. In proving the first thesis (the universality of reason, the paper contrasts Western thought, epitomized in scientific reason, with non-Western thinking patterns, expressed by ethno-sciences, magic rituals, and other knowledge practices. The conclusion drawn from this comparison is that both modern scientific reason and non-literate peoples thought patterns are two “cognitive modes” sharing a strong structural similarity. Building on some loci classici of anthropological literature written by Malinowski, Evans-Pritchard, and Lévi-Strauss (among others, the paper argues that although modern Western science and indigenous knowledge(s share a common rational denominator, the two cognitive modes are nonetheless hierarchical, the former being epistemically superior to the latter thanks to its unique self-correcting methodology. The paper ends by arguing the case for the possibility of understanding the Other(s by way of reason, a possibility grounded on the commonality of reason between cultures.

  1. Learning strategies and general cognitive ability as predictors of gender- specific academic achievement.

    Science.gov (United States)

    Ruffing, Stephanie; Wach, F-Sophie; Spinath, Frank M; Brünken, Roland; Karbach, Julia

    2015-01-01

    Recent research has revealed that learning behavior is associated with academic achievement at the college level, but the impact of specific learning strategies on academic success as well as gender differences therein are still not clear. Therefore, the aim of this study was to investigate gender differences in the incremental contribution of learning strategies over general cognitive ability in the prediction of academic achievement. The relationship between these variables was examined by correlation analyses. A set of t-tests was used to test for gender differences in learning strategies, whereas structural equation modeling as well as multi-group analyses were applied to investigate the incremental contribution of learning strategies for male and female students' academic performance. The sample consisted of 461 students (mean age = 21.2 years, SD = 3.2). Correlation analyses revealed that general cognitive ability as well as the learning strategies effort, attention, and learning environment were positively correlated with academic achievement. Gender differences were found in the reported application of many learning strategies. Importantly, the prediction of achievement in structural equation modeling revealed that only effort explained incremental variance (10%) over general cognitive ability. Results of multi-group analyses showed no gender differences in this prediction model. This finding provides further knowledge regarding gender differences in learning research and the specific role of learning strategies for academic achievement. The incremental assessment of learning strategy use as well as gender-differences in their predictive value contributes to the understanding and improvement of successful academic development.

  2. Learning strategies and general cognitive ability as predictors of gender- specific academic achievement.

    Science.gov (United States)

    Ruffing, Stephanie; Wach, F-Sophie; Spinath, Frank M; Brünken, Roland; Karbach, Julia

    2015-01-01

    Recent research has revealed that learning behavior is associated with academic achievement at the college level, but the impact of specific learning strategies on academic success as well as gender differences therein are still not clear. Therefore, the aim of this study was to investigate gender differences in the incremental contribution of learning strategies over general cognitive ability in the prediction of academic achievement. The relationship between these variables was examined by correlation analyses. A set of t-tests was used to test for gender differences in learning strategies, whereas structural equation modeling as well as multi-group analyses were applied to investigate the incremental contribution of learning strategies for male and female students' academic performance. The sample consisted of 461 students (mean age = 21.2 years, SD = 3.2). Correlation analyses revealed that general cognitive ability as well as the learning strategies effort, attention, and learning environment were positively correlated with academic achievement. Gender differences were found in the reported application of many learning strategies. Importantly, the prediction of achievement in structural equation modeling revealed that only effort explained incremental variance (10%) over general cognitive ability. Results of multi-group analyses showed no gender differences in this prediction model. This finding provides further knowledge regarding gender differences in learning research and the specific role of learning strategies for academic achievement. The incremental assessment of learning strategy use as well as gender-differences in their predictive value contributes to the understanding and improvement of successful academic development. PMID:26347698

  3. Learning strategies and general cognitive ability as predictors of gender- specific academic achievement

    Directory of Open Access Journals (Sweden)

    Stephanie eRuffing

    2015-08-01

    Full Text Available Recent research has revealed that learning behavior is associated with academic achievement at the college level, but the impact of specific learning strategies on academic success as well as gender differences therein are still not clear. Therefore, the aim of this study was to investigate gender differences in the incremental contribution of learning strategies over general cognitive ability in the prediction of academic achievement. The relationship between these variables was examined by correlation analyses. A set of t-tests was used to test for gender differences in learning strategies, whereas structural equation modelling as well as multi-group analyses were applied to investigate the incremental contribution of learning strategies for male and female students’ academic performance. The sample consisted of 461 students (mean age=21.2 years, SD=3.2. Correlation analyses revealed that general cognitive ability as well as the learning strategies effort, attention, and learning environment were positively correlated with academic achievement. Gender differences were found in the reported application of many learning strategies. Importantly, the prediction of achievement in structural equation modeling revealed that only effort explained incremental variance (10% over general cognitive ability. Results of multi-group analyses showed no gender differences in this prediction model. This finding provides further knowledge regarding gender differences in learning research and the specific role of learning strategies for academic achievement. The incremental assessment of learning strategy use as well as gender-differences in their predictive value contributes to the understanding and improvement of successful academic development.

  4. What counts as a reasonable extent? - a systems approach for understanding fire safety in Sweden

    OpenAIRE

    Larsson, Miranda; Grunnesjö, Erik; Bergström, Johan

    2012-01-01

    Swedish legislation requires that any owner or user of a building maintain a reasonable level of fire protection measures to ensure the safety of all people located in the building. If a building, in the wake of a fire, in court is determined not to have had a reasonable fire protection, the blame will likewise be assigned to the building owner or user. Using the perspective of risk governance, this study aims at analysing how regulation and stakeholders interact to maintain a specific level ...

  5. Analogical Reasoning as a Decision Support Principle for Weakly-Structured Marketing Problems

    NARCIS (Netherlands)

    N.A.P. Althuizen (Niek)

    2006-01-01

    textabstractMany marketing problems are weakly-structured. From the psychological literature, we know that analogical reasoning is an effective problem-solving method in weakly-structured decision situations. That is, when confronted with such a problem, one of the first things managers will natural

  6. Reasons for Cannabis Use and Effects of Cannabis Use as Reported by Patients with Psychotic Disorders

    NARCIS (Netherlands)

    N. Dekker; D.H. Linszen; L. de Haan

    2009-01-01

    Background: Cannabis is one of the most commonly used substances in patients with a psychotic disorder and is associated with a higher risk of psychotic relapses. Identifying reasons for cannabis use and subjective effects in patients with psychotic disorders can provide insight into the functions o

  7. Oppositional Defiance, Moral Reasoning and Moral Value Evaluation as Predictors of Self-Reported Juvenile Delinquency

    Science.gov (United States)

    Beerthuizen, Marinus G. C. J.; Brugman, Daniel; Basinger, Karen S.

    2013-01-01

    This study investigated the relationships among oppositional defiant attitudes, moral reasoning, moral value evaluation and self-reported delinquent behaviour in adolescents ("N" = 351, "M"[subscript AGE] = 13.8 years, "SD"[subscript AGE] = 1.1). Of particular interest were the moderating effects of age, educational…

  8. Proportional reasoning as a threshold to numeracy at university: A framework for analysis

    Directory of Open Access Journals (Sweden)

    Pam Lloyd

    2013-09-01

    Full Text Available There is a generally acknowledged need for students to be quantitatively literate in an increasingly quantitative world. This includes the ability to reason critically about data in context. We have noted that students experience difficulty with the application of certain mathematical and statistical concepts, which in turn impedes progress in the development of students’ critical reasoning ability. One such concept, which has the characteristics of a threshold concept, is that of proportional reasoning. The main focus of this article is a description of the development of a framework using an adapted phenomenographic approach that can be used to describe students’ experiences in the acquisition of the concept of comparing quantities in relative terms. The framework has also helped to make explicit the elements that constitute a full understanding of the requirements for the proportional comparison of quantities. Preliminary results from using the framework to analyse students’ responses to assessment questions showed that many students were challenged by proportional reasoning. When considering the notion of the liminal space that is occupied en route to a full understanding of a threshold concept, about half of the students in the study were at the preliminal stage of understanding the concept and very few were at the threshold.

  9. Theories of reasoned action and planned behavior as models of condom use: a meta-analysis.

    Science.gov (United States)

    Albarracín, D; Johnson, B T; Fishbein, M; Muellerleile, P A

    2001-01-01

    To examine how well the theories of reasoned action and planned behavior predict condom use, the authors synthesized 96 data sets (N = 22,594) containing associations between the models' key variables. Consistent with the theory of reasoned action's predictions, (a) condom use was related to intentions (weighted mean r. = .45), (b) intentions were based on attitudes (r. = .58) and subjective norms (r. = .39), and (c) attitudes were associated with behavioral beliefs (r. = .56) and norms were associated with normative beliefs (r. = .46). Consistent with the theory of planned behavior's predictions, perceived behavioral control was related to condom use intentions (r. = .45) and condom use (r. = .25), but in contrast to the theory, it did not contribute significantly to condom use. The strength of these associations, however, was influenced by the consideration of past behavior. Implications of these results for HIV prevention efforts are discussed.

  10. Theories of reasoned action and planned behavior as models of condom use: a meta-analysis.

    Science.gov (United States)

    Albarracín, D; Johnson, B T; Fishbein, M; Muellerleile, P A

    2001-01-01

    To examine how well the theories of reasoned action and planned behavior predict condom use, the authors synthesized 96 data sets (N = 22,594) containing associations between the models' key variables. Consistent with the theory of reasoned action's predictions, (a) condom use was related to intentions (weighted mean r. = .45), (b) intentions were based on attitudes (r. = .58) and subjective norms (r. = .39), and (c) attitudes were associated with behavioral beliefs (r. = .56) and norms were associated with normative beliefs (r. = .46). Consistent with the theory of planned behavior's predictions, perceived behavioral control was related to condom use intentions (r. = .45) and condom use (r. = .25), but in contrast to the theory, it did not contribute significantly to condom use. The strength of these associations, however, was influenced by the consideration of past behavior. Implications of these results for HIV prevention efforts are discussed. PMID:11271752

  11. A STUDY OF ADOLESCENTS’ ANXIETY AND ACHIEVEMENT IN ENGLISH AS A FOREIGN LANGUAGE

    Directory of Open Access Journals (Sweden)

    Ridha Fadillah

    2011-10-01

    Full Text Available This paper aims at investigating whether there is relationship between students’ anxiety and students’ achievement in English as a foreign language among adolescents at Sekolah Menengah Umum Negeri 1 Banjarbaru, South Kalimantan. The sample was 152 students of sixteen and seventeen years old at second grade. The results indicate that the students’ anxiety in learning English as foreign language is at moderate level. There is no significant relationship between English language anxiety and students’ achievement in English as a foreign language as a whole. But a significant negative correlation between test anxiety and students’ achievement is indicated. And the difference of English language anxiety between male and female occurred on communication apprehension, it shows that female is more apprehensive than male in English communication but for overall anxiety, there is no difference in English language anxiety by gender at second grade in this school.

  12. State downsizing as a determinant of infant mortality and achievement of Millennium Development Goal 4

    OpenAIRE

    Palma Solís, Marco Antonio; Álvarez-Dardet Díaz, Carlos; Franco Giraldo, Álvaro; Hernández Aguado, Ildefonso; Pérez Hoyos, Santiago

    2009-01-01

    The aim of this study was to evaluate the worldwide effect of state downsizing policies on achievement of U.N. Millennium Development Goal 4 (MDG4) on infant mortality rates. In an ecological retrospective cohort study of 161 countries, from 1978 to 2002, the authors analyzed changes in government consumption (GC) as determining exposure to achievement of MDG4. Descriptive methods and a multiple logistic regression were applied to adjust for changes in gross domestic product, level of democra...

  13. Voices from Social Work Graduates in China: Reasons for Not Choosing Social Work as a Career.

    Science.gov (United States)

    Zeng, Shouchui; Cheung, Monit; Leung, Patrick; He, Xuesong

    2016-01-01

    Although previous studies have addressed turnover issues after being a social worker, this study identifies factors that may block initial entry to the profession. Using a semistructural interview method with 20 BSW graduates, the researchers transcribed the reasons for BSW graduates not entering a career in social work. Through element-centered content analysis, 76 reasons were sorted into nine categories: (1) income insufficient for basic needs, (2) unclear future, (3) no commitment to social work, (4) social work jobs could be taken by other professionals, (5) difficulties in actualizing proclaimed value, (6) personally unable to apply skills, (7) social exclusion due to nonresident status, (8) hard/stressful work, and (9) not supported by peers and family. Through person-centered content analysis, most respondents (90 percent) reported multiple reasons (M = 3.8) supporting their decision, offering their rational thought processes culminating in the decision not to enter social work. Recommendations for developing a national survey, engaging social workers in preparing BSW students for graduation, and modifying student admissions strategies are discussed.

  14. Of Pigs and Men: Understanding Students' Reasoning about the Use of Pigs as Donors for Xenotransplantation

    Science.gov (United States)

    Lindahl, Mats Gunnar

    2010-01-01

    Two important roles of education are to provide students with knowledge for their democratic participation in society and to provide knowledge for a future profession. In science education, students encounter values that may be in conflict with their worldview. Such conflicts may, for example, lead to constructive reflections as well as rejection…

  15. Making Methods Work in Software Engineering : Method Deployment - as a Social Achievement

    OpenAIRE

    Rönkkö, Kari

    2005-01-01

    The software engineering community is concerned with improvements in existing methods and development of new and better methods. The research approaches applied to take on this challenge have hitherto focused heavily on the formal and specifying aspect of the method. This has been done for good reasons, because formalizations are the means in software projects to predict, plan, and regulate the development efforts. As formalizations have been successfully developed new challenges have been re...

  16. Science achievement as an indicator of educational opportunity available in rural K--12 districts in Texas

    Science.gov (United States)

    Capehart, Cheryl Louise

    Purpose of the study. This study examined Rural K--12 Texas districts to investigate whether science achievement could serve as a gauge to measure the availability and quality of rigorous educational opportunities in Rural Texas districts. Procedure. A Case II criterion-group design was used; 2 groups of districts were selected based on their 3-year performances on the 8th grade Science Texas Assessment of Academic Skills (TAAS)---the statewide criterion-referenced test. The High Performing Group (HPG) was composed of 30 top performing districts; the Low Performing Group (LPG) was composed of 30 lowest performing districts. Data collection was limited to archived quantitative data from Texas Education Agency's open records. Achievement variables were percent passing (1) Science TASS, (2) Biology End-of-Course (EoC) test and (3) the composite passing all Reading, Writing, and Mathematics TAAS. Academic variables were percent participating in (1) advanced courses, (2) rigorous graduation programs, and (3) college entrance examinations. District quality indicators also included 3 budget variables: (1) average teacher salary, (2) per pupil instructional expenditure, (3) percent allocated for instructional leadership; and 4 staff variables: (1) percent teachers fully certified, (2) percent teachers with advanced degrees, (3) average years teacher experience, (4) average percent non-turnover of teachers. One score per variable was obtained for each district. The HPG and LPG were compared on each variable using the group means, standard deviations, standard errors of the mean, Levene's test for equality of variance, and a t test for equality of means with a 95% confidence level. The Pearson correlation with two-tailed significance calculated the relationship of each independent variable (budget and staff factors) to each dependent variable (performance measures). Science TASS and a Combined Science score (grand mean of Science TASS & Biology EoC passing rates) were

  17. Factors related to academic grades as a proxy for educational achievement

    Directory of Open Access Journals (Sweden)

    Ianina Tuñón

    2016-01-01

    Full Text Available After eleven years of the Argentine government implementing different educational engagement policies, it is appropriate to look into the achievements in education. What sociodemographic, socioeconomic and sociocultural factors are linked to academic grades as a proxy for educational achievement in subjects such as Mathematics and Language in primary and secondary education? This study shows relatively well-known inequalities relating to sex and educational paths. Nevertheless, other influential sociocultural factors were explored which are relatively independent from socioeconomic and school administration factors, such as having books at home, reading behavior and storytelling. Moreover, the relationship between social stratification and the type of school management was identified. In order to achieve this, analyses were performed using logistic regression models based on microdata from the Argentine Social Debt Survey for 2011.

  18. Examination of the Relationship Between Autonomy and English Achievement as Mediated by Foreign Language Classroom Anxiety.

    Science.gov (United States)

    Ghorbandordinejad, Farhad; Ahmadabad, Roghayyeh Moradian

    2016-06-01

    This study investigated the relationship between autonomy and English language achievement among third-grade high school students as mediated by foreign language classroom anxiety in a city in the north-west of Iran. A sample of 400 students (187 males, and 213 females) was assessed for their levels of autonomy and foreign language anxiety using the Autonomy Questionnaire and Foreign Language Classroom Anxiety Scale (FLCAS), respectively. Participants' scores on their final English exam were also used as the measurement of their English achievement. The results of Pearson correlation revealed a strong correlation between learners' autonomy and their English achievement (r [Formula: see text] .406, n [Formula: see text] 400, [Formula: see text]). Also, foreign language classroom anxiety was found to be significantly and negatively correlated with English achievement (r [Formula: see text] [Formula: see text].472, n [Formula: see text] 400, [Formula: see text]). Hierarchical multiple regression was used to assess the ability of autonomy to predict language learning achievement, after controlling for the influence of anxiety. In sum, the results of hierarchical multiple regressions revealed that foreign language classroom anxiety significantly mediates the relationship between autonomy and English language achievement. Implications for both teachers and learners, and suggestions for further research are provided.

  19. Examination of the Relationship Between Autonomy and English Achievement as Mediated by Foreign Language Classroom Anxiety.

    Science.gov (United States)

    Ghorbandordinejad, Farhad; Ahmadabad, Roghayyeh Moradian

    2016-06-01

    This study investigated the relationship between autonomy and English language achievement among third-grade high school students as mediated by foreign language classroom anxiety in a city in the north-west of Iran. A sample of 400 students (187 males, and 213 females) was assessed for their levels of autonomy and foreign language anxiety using the Autonomy Questionnaire and Foreign Language Classroom Anxiety Scale (FLCAS), respectively. Participants' scores on their final English exam were also used as the measurement of their English achievement. The results of Pearson correlation revealed a strong correlation between learners' autonomy and their English achievement (r [Formula: see text] .406, n [Formula: see text] 400, [Formula: see text]). Also, foreign language classroom anxiety was found to be significantly and negatively correlated with English achievement (r [Formula: see text] [Formula: see text].472, n [Formula: see text] 400, [Formula: see text]). Hierarchical multiple regression was used to assess the ability of autonomy to predict language learning achievement, after controlling for the influence of anxiety. In sum, the results of hierarchical multiple regressions revealed that foreign language classroom anxiety significantly mediates the relationship between autonomy and English language achievement. Implications for both teachers and learners, and suggestions for further research are provided. PMID:25941040

  20. Using a multi-agent evidential reasoning network as the objective function for an evolutionary algorithm

    Science.gov (United States)

    Woodley, Robert; Lindahl, Eric; Barker, Joseph

    2007-04-01

    A culturally diverse group of people are now participating in military multinational coalition operations (e.g., combined air operations center, training exercises such as Red Flag at Nellis AFB, NATO AWACS), as well as in extreme environments. Human biases and routines, capabilities, and limitations strongly influence overall system performance; whether during operations or simulations using models of humans. Many missions and environments challenge human capabilities (e.g., combat stress, waiting, fatigue from long duty hours or tour of duty). This paper presents a team selection algorithm based on an evolutionary algorithm. The main difference between this and the standard EA is that a new form of objective function is used that incorporates the beliefs and uncertainties of the data. Preliminary results show that this selection algorithm will be very beneficial for very large data sets with multiple constraints and uncertainties. This algorithm will be utilized in a military unit selection tool.

  1. Baby cuff as a reason for laryngeal mask airway cuff malfunction during airway management for anesthesia

    OpenAIRE

    Jafar Rahimi Panahi; Ata Mahmoodpoor; Golzari, Samad E. J.; Hassan Soleimanpour

    2014-01-01

    Placement of laryngeal mask airway (LMA) is a blind procedure without requiring laryngoscopy. The reported success rate for LMA insertion at the first attempt is almost 95%; however, many functioning LMAs may not be in an ideal anatomic place. It seems that disposable LMAs have more stable cuff pressure compared to reusable LMAs; therefore, Anesthesiologists should bear in mind this fact when using reusable LMAs to achieve a proper sealing and safe airway management. In this report, we introd...

  2. Quantum theory as plausible reasoning applied to data obtained by robust experiments.

    Science.gov (United States)

    De Raedt, H; Katsnelson, M I; Michielsen, K

    2016-05-28

    We review recent work that employs the framework of logical inference to establish a bridge between data gathered through experiments and their objective description in terms of human-made concepts. It is shown that logical inference applied to experiments for which the observed events are independent and for which the frequency distribution of these events is robust with respect to small changes of the conditions under which the experiments are carried out yields, without introducing any concept of quantum theory, the quantum theoretical description in terms of the Schrödinger or the Pauli equation, the Stern-Gerlach or Einstein-Podolsky-Rosen-Bohm experiments. The extraordinary descriptive power of quantum theory then follows from the fact that it is plausible reasoning, that is common sense, applied to reproducible and robust experimental data.

  3. Quantum theory as plausible reasoning applied to data obtained by robust experiments.

    Science.gov (United States)

    De Raedt, H; Katsnelson, M I; Michielsen, K

    2016-05-28

    We review recent work that employs the framework of logical inference to establish a bridge between data gathered through experiments and their objective description in terms of human-made concepts. It is shown that logical inference applied to experiments for which the observed events are independent and for which the frequency distribution of these events is robust with respect to small changes of the conditions under which the experiments are carried out yields, without introducing any concept of quantum theory, the quantum theoretical description in terms of the Schrödinger or the Pauli equation, the Stern-Gerlach or Einstein-Podolsky-Rosen-Bohm experiments. The extraordinary descriptive power of quantum theory then follows from the fact that it is plausible reasoning, that is common sense, applied to reproducible and robust experimental data. PMID:27091169

  4. Anxiety and inattention as predictors of achievement in early elementary school children.

    Science.gov (United States)

    Grills-Taquechel, Amie E; Fletcher, Jack M; Vaughn, Sharon R; Denton, Carolyn A; Taylor, Pat

    2013-01-01

    The objective of this study was to examine the relations among anxiety, inattention, and math/reading achievement, as well as the mediating/moderating role of inattention in the anxiety-achievement association both concurrently and longitudinally. Participants included 161 ethnically diverse children (aged 6-8) and their teachers. At the middle and end of first grade (approximately 5 months apart), students completed measures of anxiety and achievement while their teachers completed a measure of inattention. For the concurrent analyses, greater harm avoidance anxiety was associated with better attention, which was in turn related to better achievement. For the longitudinal analyses, mid-year inattention interacted with harm avoidance and separation anxiety to predict end of year reading fluency. For those rated as more attentive, greater separation anxiety symptoms were associated with decreased fluency performance while greater harm avoidance symptoms were associated with increased performance. Findings were discussed in terms of the importance of considering socioemotional variables in the study of children's academic achievement and the potential utility of early anxiety prevention/intervention programs, especially for children experiencing academic difficulties who also show internalizing behaviors.

  5. Moral Development as the Personal Education of Feeling and Reason: From James to Piaget

    Science.gov (United States)

    Ferrari, Michel; Okamoto, Carol M.

    2003-01-01

    This article traces the connection between William James's writings in "The Varieties of Religious Experience" and Jean Piaget's work on moral development through Piaget's early work on religious experience. James characterises religious experience as unlocking deep personal power that can sustain a "strenuous mood". These ideas impacted the early…

  6. Reasons for Errors Done by Belarusian Learners Learning Turkish as a Foreign Language

    Science.gov (United States)

    Tum, Gulden

    2012-01-01

    Teaching Turkish as a Foreign Language (TFL) has gained importance recently and several studies are carried out in this field. Especially, learners of linguistically different communities (Byelorussian/Russian) are observed to make errors while learning Turkish. If making errors is an integral outcome in learning a TFL, then to what extent is it…

  7. Physical Activity as a Moderator of the Relationship between Aging and Inductive Reasoning

    Science.gov (United States)

    Perrot, Alexandra; Gagnon, Christine; Bertsch, Jean

    2009-01-01

    A relatively universal observation in aging studies is that cognitive functions inevitably decline across the adult life span. More specifically, executive functions decline substantially with age, as do the frontal and prefrontal brain regions that support them. Indeed, these regions are subject to important neurological modifications with…

  8. Big Business Going to Bat for NCLB: Competitiveness Is Cited as Reason to Retain Law

    Science.gov (United States)

    Hoff, David J.

    2006-01-01

    Large companies and major business groups are known for hiring well-heeled lobbyists to push for their interests, especially in such areas as tax and spending laws. Their federal lobbying presence on education issues has been relatively modest. The author discusses the U.S. Chamber of Commerce and the Business Roundtable--two prominent…

  9. Natural disasters as one of the reasons for the existence of insurance

    OpenAIRE

    Oksana Syslyakova

    2014-01-01

    In work the essence and types of natural disasters are considered, dynamics and structure of emergency events in Russia in 2010-2013 is analysed, need of application of insurance as effective mechanism of protection of the state and society from various natural disasters is proved.

  10. Five Good Reasons for Engineering as the Focus for Technology Education

    OpenAIRE

    Wicklein, Robert C.

    2006-01-01

    The article presents information on a paper which discusses why engineering design should be the focus for technology education. Technology education is still viewed as a non-essential instructional program and this is because school administrators and counselors have inadequate understanding of it. Even general populace have inadequate understanding concerning technology education. The pervasiveness of technology literally affects every living creature in our society. Therefore, it is of cri...

  11. Poor glycemic control as a reason for referral of diabetes patients to specialists in Israel

    OpenAIRE

    Fogelman, Yacov; Karkabi, Khaled; Goldfracht, Margalit

    2016-01-01

    Aims/introduction: Family physicians face the dilemma of when to refer patients with diabetes to specialists. This study examined attitudes of family physicians to referring patients with poor glucose control to diabetes specialists.Materials and methods: At continuous medical education courses, family physicians were asked to respond anonymously, as to whether they generally manage the diabetes of their patients, and specifically those with poor glycemic control (HbA1c>9.0%).Results: Of 4...

  12. The Interrogative Model of inquiry as a logic of scientific reasoning

    OpenAIRE

    Mutanen, Arto

    2011-01-01

    Questioning has been understood as a general method for knowledge seeking in philosophy for thousands of years. The first systematic questioning approach in the (written) history of philosophy is the Socratic Method of Questioning (elenchus). The strategy of questioning is the central part of the Socratic Method of Questioning. Hintikka has developed a logico-philosophical model called the Interrogative Model of Inquiry, in which he systematizes the questioning method. The notion of strategy ...

  13. The Effects of Mathematics Anxiety on Matriculation Students as Related to Motivation and Achievement

    Science.gov (United States)

    Zakaria, Effandi; Nordin, Norazah Mohd

    2008-01-01

    The study investigated the effects of mathematics anxiety on matriculation students as related to motivation and achievement. Subjects included 88 students who were at the end of their second semester of study. Anxiety and motivation were measured using the Fennema-Sherman Math Anxiety Scale (MAS) and Effectance Motivation Scale (EMS)…

  14. Educational Achievement as Defining Factor in Social Stratification in Contemporary Spain

    Science.gov (United States)

    Colmenero, Manuel Jacinto Roblizo

    2013-01-01

    One especially relevant key theme in Sociology of Education is to what extent parents' cultural level has significant implications in students' educational achievement and, as a consequence, in the social mobility inherently linked to level of education and professional training. In order to investigate this aspect on current Spanish society, our…

  15. Institutional Factors as Predictors of Students' Academic Achievement in Colleges of Education in South Western Nigeria

    Science.gov (United States)

    Adeyemi, Abisola Moradeyo; Adeyemi, Seminu Babatunde

    2014-01-01

    The enhancement of the academic achievement of the Nigerian students has continued to engage the attention of educational practitioners and policy makers. This paper investigated institutional factors as predictors of students' academic performance in Colleges of Education in South-Western Nigeria. The study employed the ex post facto design using…

  16. Attitude and Motivation as Predictors of Academic Achievement of Students in Clothing and Textiles

    Science.gov (United States)

    Uwameiye, B. E.; Osho, L. E.

    2011-01-01

    This study investigated attitude and motivation as predictors of academic achievement of students in clothing and textiles. Three colleges of education in Edo and Delta States were randomly selected for use in this study. From each school, 40 students were selected from Year III using simple random technique yielding a total of 240 students. The…

  17. Trajectories of Career Aspirations through Adolescence and Young Adulthood: Early Math Achievement as a Critical Filter

    Science.gov (United States)

    Shapka, Jennifer D.; Domene, Jose F.; Keating, Daniel P.

    2006-01-01

    Growth curve modelling was used to trace the trajectory of the prestige dimension of career aspirations from Grade 9 through to 3 years after high school, as a function of gender and early high school math achievement. The sample consisted of 218 university-bound adolescents (129 female, 89 male). Initial aspiration levels, the slope, and the…

  18. Mathematics Achievement as a Function of within- and between-School Differences

    Science.gov (United States)

    Mohammadpour, Ebrahim; Abdul Ghafar, Mohamed Najib

    2014-01-01

    Achievement in mathematics of eighth-grade students is modeled as a function of within-school, between-school and cross-country differences. The data were obtained from 217,728 students, within 7,216 secondary schools, in 48 countries, who participated in the 2007 Trends in International Mathematics and Science Study. Multilevel analysis showed…

  19. Emotional Intelligence and Gender as Predictors of Academic Achievement among Some University Students in Barbados

    Science.gov (United States)

    Fayombo, Grace A.

    2012-01-01

    This study investigated emotional intelligence (attending to emotion, positive expressivity and negative expressivity) and gender as predictors of academic achievement among 163 undergraduate psychology students in The University of the West Indies (UWI), Cave Hill Campus, Barbados. Results revealed significant positive and negative correlations…

  20. Vocational Identity Achievement as a Mediator of Presence of Calling and Life Satisfaction

    Science.gov (United States)

    Hirschi, Andreas; Herrmann, Anne

    2012-01-01

    The present study explores what mechanism might be responsible for the reported link between presence of a calling in one's career and life satisfaction. It is proposed that vocational identity achievement acts as one important mediator of this relation and that the effects can be observed even when controlling for core self-evaluations (CSEs).…

  1. Socio-Economic Background and Access to Internet as Correlates of Students' Achievement in Agricultural Science

    Science.gov (United States)

    Adegoke, Sunday Paul; Osokoya, Modupe M.

    2015-01-01

    This study investigated access to internet and socio-economic background as correlates of students' achievement in Agricultural Science among selected Senior Secondary Schools Two Students in Ogbomoso South and North Local Government Areas. The study adopted multi-stage sampling technique. Simple random sampling was used to select 30 students from…

  2. Defining as a Mathematical Activity: A Framework for Characterizing Progress from Informal to More Formal Ways of Reasoning

    Science.gov (United States)

    Zandieh, Michelle; Rasmussen, Chris

    2010-01-01

    The purpose of this paper is to further the notion of defining as a mathematical activity by elaborating a framework that structures the role of defining in student progress from informal to more formal ways of reasoning. The framework is the result of a retrospective account of a significant learning experience that occurred in an undergraduate…

  3. Time Perspective and School Membership as Correlates to Academic Achievement among African American Adolescents

    Science.gov (United States)

    Adelabu, Detris Honora

    2007-01-01

    This study examined the relationship of academic achievement to time perspective (future, present) and school membership (belonging, acceptance, rejection) among 232 low-income, urban African American adolescents. Findings indicated positive, significant relationships among academic achievement, future time perspective, school belonging, and…

  4. Radiation dosage during pediatric diagnostic or interventional cardiac catheterizations using the "air gap technique" and an aggressive "as low as reasonably achievable" radiation reduction protocol in patients weighing < 20 kg

    Directory of Open Access Journals (Sweden)

    Frank A Osei

    2016-01-01

    Results: One-hundred and twenty-seven patients underwent 151 procedures within the study period. The median age was 1.2 years (range: 1 day to 7.9 years and median weight was 8.8 kg (range: 1.9-19.7. Eighty-nine (59% of the procedures were interventional. The median total fluoro time was 13 min [interquartile range (IQR 7.3-21.8]. The median total air Kerma (K product was 55.6 mGy (IQR 17.6-94.2 and dose area product (DAP was 189 Gym2 (IQR 62.6-425.5. Conclusion: Use of a novel ALARA and AGT protocol for cardiac catheterizations in children markedly reduced radiation exposure to levels far below recently reported values.

  5. Haag's Theorem as a Reason to Reconsider Direct-Action Theories

    CERN Document Server

    Kastner, R E

    2015-01-01

    It is argued that the severe consequences of Haag's inconsistency theorem for relativistic quantum field theories can be successfully evaded in the direct-action approach. Some recent favorable comments of John Wheeler, often mistakenly presumed to have abandoned his own (and Feynman's) direct-action theory, together with the remarkable immunity of direct-action quantum electrodynamics to Haag's theorem, suggest that it may well be a good time to rehabilitate direct action theories. It is also noted that, as extra dividends, direct-action QED is immune to the self-energy problem of standard gauge field QED, and can also provide a solution to the problem of gauge arbitrariness.

  6. Performance-Based Pay as a Motivational Tool for Achieving Organisational Performance: An Exploratory Case Study

    OpenAIRE

    Francis Boachie-Mensah; Ophelia Delali Dogbe

    2011-01-01

    The issue of employees’ performance in furtherance of organisational objectives has occupied managementattention for long. Differences in levels of performance have been attributed to differences in skills and abilitieson the one hand, and to different theories of money on the other. This study examined the issue ofperformance-based pay as a motivational tool for achieving organisational performance, using the situation in amanufacturing company in Ghana as a case study. The main objective of...

  7. A Phenomenological Investigation of Student Achievement: Perceptions of Academic Success as Told by Single African American and Hispanic Mothers

    Science.gov (United States)

    Stewart, Shawn M.

    2010-01-01

    A number of factors seem to contribute to low student achievement in the organization of education. Some of these factors exist prior to children reaching school age. It seems as though a vast quantity of minority students struggle academically. Research supports the belief that socioeconomic status, ethnicity, and single-parent families have an…

  8. Longitudinal drift of substorm electrons as the reason of impulsive precipitation events and VLF emissions

    Directory of Open Access Journals (Sweden)

    A. A. Lubchich

    2006-10-01

    Full Text Available Using the data from satellite CRRES and three geostationary LANL spacecraft, the propagation of an electron cloud from midnight to the evening sector is investigated. An electron cloud was injected during a weak isolated substorm that developed on a quiet geomagnetic background. It is found that within the local time sector from 03:00 until at least 08:00 MLT, the propagation of electrons at perpendicular pitch-angles is well described by a simple model of drift in the dipole magnetic field. The flux levels in the field-aligned electrons increase simultaneously with the flux at perpendicular pitch angles, which is attributed to the pitch angle diffusion by the whistler mode. This pitch-angle diffusion leads to precipitation of electrons from a drifting cloud and an increase in the ionospheric electron density, simultaneously observed above Tromsø, Norway, by the EISCAT UHF radar in the morning sector (04:40–05:25 MLT. The precipitation develops as quasi-periodic pulses with a period of about 100 s. We discuss the models of pulsating precipitation due to the whistler cyclotron instability and show that our observations can be explained by such a model.

  9. Student motivation and achievement in learning English as a second language using Second Life

    Directory of Open Access Journals (Sweden)

    Tosti H. C. Chiang

    2014-03-01

    Full Text Available This study investigates the impact of a 3D virtual learning environment based on Second Life on student motivation and achievement in learning English as a second language. Twenty-one university students participate in this study, with the support of an English instructor. The Motivated Strategies for Learning Questionnaire (MSLQ was used to evaluate students’ intrinsic and extrinsic goal orientation and self-efficacy in Second Life. The pre-test and post-test were used to assess students’ learning achievement. The results showed that students’ intrinsic and extrinsic goal orientations in English learning in Second Life had a positive influence on their self-efficacy. In addition, students’ self-efficacy of English learning in Second Life was found to positively relate to their learning achievement. Moreover, students’ intrinsic and extrinsic goal orientations were found to significantly influence their learning achievement via self-efficacy. In other words, instructors can utilize Second Life to enhance student motivation and achievement in English learning.

  10. The -Younger-Minority Boy" as a Clue to the Source of Achievement Orientation.

    Science.gov (United States)

    Kammeyer, Kenneth C. W.

    This study is a follow-up of the work by Morris Rosenberg who found that younger-minority boys tend to have high self-esteem, but a relatively low achievement orientation and low grades in school. Sampling a total 898 high school senior boys, this study found that younger minority boys do have lower grades and lower occupational and educational…

  11. What Counts as "Truth" -- Reason Versus Emotion in Vaccine Decision Making

    Science.gov (United States)

    Mnookin, S.

    2014-12-01

    Vaccines are without question one of the most successful public health interventions the world has ever known. Despite this, for the past decade-and-a-half, industrialized countries around the world, from the United States to Germany and from Australia to Israel, have been confronted with specious panics about vaccine safety and efficacy, many of which center around claims that vaccines can cause autism. These fears can be traced to two events: a since-retracted paper published by a disgraced gastroenterologist claiming the measles-mumps-rubella vaccine was linked to a gut disease which, in turn, was linked to autism; and the United States's decision to remove a mercury-based preservative called thimerosal from standard pediatric vaccines in the late 1990s. The effects of these scares are being felt worldwide. Each year for the past several years, the US has had more measles outbreaks than at any time since the mid-1990s, a fact which is especially frightening given that the WHO declared measles eliminated from North America in 2000. In France, a nationwide measles outbreak has caused thousands of hospitalizations and a number of deaths. I will address several issues central to this topic: Given the overwhelming amount of evidence showing vaccines are safe and the total lack of evidence showing they cause autism, why do these fears persist, and what can be done to combat them? Has the public health establishment's response to these fears been sufficient? To what extent do concerns about vaccines function as proxies for more opaque concerns regarding modern-day health care? And finally, what is the effect of a lack of evidence-based research on the best way to combat misinformation?

  12. Obstructive Sleep Apnea Hypopnea Syndrome as a Reason for Active Management of Pulmonary Embolism

    Institute of Scientific and Technical Information of China (English)

    Jiang Xie; Yong-Xiang Wei; Shuang Liu; Wei Zhang; Xiang-Feng Zhang; Jie Li

    2015-01-01

    Background:Obstructive sleep apnea hypopnea syndrome (OSAHS) constitutes an independent factor for high warfarin dose for patients with pulmonary embolism (PE).The aim of this study was to investigate whether the 6-month anticoagulation treatment by warfarin is enough for patients with PE complicated by OSAHS.Methods:We investigated 97 PE patients,32 of them had OSAHS and 65 non-OSAHS.Warfarin was administered for 6-month if no abnormal circumstances occurred.All patients were followed up for 18 months.Adverse events (AE) included death,major bleeding,hospitalization due to heart failure or pulmonary hypertension,and recurrence or aggravation of PE (including deep vein thrombosis).Recurrence rate of PE after warfarin cessation was compared between the two groups.Results:OSAHS patients required a significantly higher dose of warfarin than their non-OSAHS counterparts (4.73 mg vs.3.61 mg,P < 0.001).During warfarin treatment,no major bleeding and aggravation of PE occurred among OSAHS patients,and the rates of various AE were not significantly different between the OSAHS and non-OSAHS groups.PE recurrence was higher in OSAHS than non-OSAHS groups after withdrawal of warfarin (21.43% vs.6.78%,P =0.047).Compared with non-OSAHS patients,OSAHS group had lower international normalized ratio (INR) value but higher plasminogen on baseline and INR resumed to a relatively low level after warfarin discontinuation.Conclusions:OSAHS patients may present with hypercoagulation and relatively high-risk of recurrence of PE after cessation of 6-month warfarin treatment.

  13. Reasons for choosing dentistry as a career: a study involving male and female first-year students in Peru.

    Science.gov (United States)

    Bernabé, E; Icaza, J L; Delgado-Angulo, E K

    2006-11-01

    The aim of this study was to compare the reported reasons to choose dentistry as a career between Peruvian male and female first-year students. A self-completion questionnaire was administered to 75 first-year students registered at the Faculty of Dentistry of the Universidad Peruana Cayetano Heredia, Lima, Peru. The questionnaire comprised 16 items grouped into four categories (economic, professional, vocational and personal background). Students rated the importance of each item for selecting dentistry as a career on a Likert-type scale of five points. The Mann-Whitney test was used to compare groups and item scores by gender. A male/female proportion of 1/2.1 was found in the pool of participating students. When group and item scores were compared between genders, statistically significant differences were only found for vocational and personal background reasons (P < 0.05); however, the three reasons that obtained higher scores for each gender were found to be different. It is recommended that further studies be conducted to increase the sample, by extending the study and evaluating not only reasons for choosing dentistry, but also other factors that may influence the decision. PMID:17038016

  14. 3D lumped LC resonators as low mass axion haloscopes

    Science.gov (United States)

    McAllister, Ben T.; Parker, Stephen R.; Tobar, Michael E.

    2016-08-01

    The axion is a hypothetical particle considered to be the most economical solution to the strong C P problem. It can also be formulated as a compelling component of dark matter. The haloscope, a leading axion detection scheme, relies on the conversion of galactic halo axions into real photons inside a resonant cavity structure in the presence of a static magnetic field, where the generated photon frequency corresponds to the mass of the axion. For maximum sensitivity it is key that the central frequency of the cavity mode structure coincides with the frequency of the generated photon. As the mass of the axion is unknown, it is necessary to perform searches over a wide range of frequencies. Currently there are substantial regions of the promising preinflationary low-mass axion range without any viable proposals for experimental searches. We show that three-dimensional resonant LC circuits with separated magnetic and electric fields, commonly known as reentrant cavities, can be sensitive dark matter haloscopes in this region, with frequencies inherently lower than those achievable in the equivalent size of empty resonant cavity. We calculate the sensitivity and accessible axion mass range of these experiments, designing geometries to exploit and maximize the separated magnetic and electric coupling of the axion to the cavity mode.

  15. A Portfolio as an Alternative Means of Presenting the University Student’s Achievements

    OpenAIRE

    Regina Gennadyevna Sakhieva; Suriya Irekovna Gilmanshina; Iskander Rafailevich Gilmanshin; Svetlana Sergeyevna Kosmodemyanskaya; Ilsia Rafailevna Akchurina; Rimma Nadyrovna Sagitova

    2014-01-01

    The article defines the objective, the tasks, the functions of the portfolio as an alternative means of presentationof the students’ achievements in higher professional school. Nowadays there is no specified structure of thestudent portfolio, it may vary according to the targets, direction, educational profile and other factors. The paperconsiders the development of the structure of the undergraduate student portfolio. It also describes the principlesof designing a portfolio, the main advanta...

  16. Competency-based assignments as a means of achieving modern educational outcomes

    OpenAIRE

    Olga Korshunova

    2016-01-01

    Based on the analysis of the transition state of the educational sphere from one educational paradigm to the other one, the article discusses the problem of interrelation of key competencies and universal learning performances as the intended learning outcomes. Transformation of the main function of the education content from the purpose of learning to the means of achieving new educational outcomes is emphasized. The concept "activity-based learning unit" is revealed on the example of compet...

  17. Theory of Mind as a Mediator of Reasoning and Facial Emotion Recognition: Findings from 200 Healthy People

    OpenAIRE

    Lee, Seul Bee; Koo, Se Jun; Song, Yun Young; Lee, Mi Kyung; JEONG, YU-JIN; Kwon, Catherine; Park, Kyoung Ri; Park, Jin Young; Kang, Jee In; Lee, Eun; An, Suk Kyoon

    2013-01-01

    Objective It was proposed that the ability to recognize facial emotions is closely related to complex neurocognitive processes and/or skills related to theory of mind (ToM). This study examines whether ToM skills mediate the relationship between higher neurocognitive functions, such as reasoning ability, and facial emotion recognition. Methods A total of 200 healthy subjects (101 males, 99 females) were recruited. Facial emotion recognition was measured through the use of 64 facial emotional ...

  18. Spatial Visualization as Mediating between Mathematics Learning Strategy and Mathematics Achievement among 8th Grade Students

    Science.gov (United States)

    Rabab'h, Belal; Veloo, Arsaythamby

    2015-01-01

    Jordanian 8th grade students revealed low achievement in mathematics through four periods (1999, 2003, 2007 & 2011) of Trends in International Mathematics and Science Study (TIMSS). This study aimed to determine whether spatial visualization mediates the affect of Mathematics Learning Strategies (MLS) factors namely mathematics attitude,…

  19. The theory of reasoned action as parallel constraint satisfaction: towards a dynamic computational model of health behavior.

    Directory of Open Access Journals (Sweden)

    Mark G Orr

    Full Text Available The reasoned action approach, although ubiquitous in health behavior theory (e.g., Theory of Reasoned Action/Planned Behavior, does not adequately address two key dynamical aspects of health behavior: learning and the effect of immediate social context (i.e., social influence. To remedy this, we put forth a computational implementation of the Theory of Reasoned Action (TRA using artificial-neural networks. Our model re-conceptualized behavioral intention as arising from a dynamic constraint satisfaction mechanism among a set of beliefs. In two simulations, we show that constraint satisfaction can simultaneously incorporate the effects of past experience (via learning with the effects of immediate social context to yield behavioral intention, i.e., intention is dynamically constructed from both an individual's pre-existing belief structure and the beliefs of others in the individual's social context. In a third simulation, we illustrate the predictive ability of the model with respect to empirically derived behavioral intention. As the first known computational model of health behavior, it represents a significant advance in theory towards understanding the dynamics of health behavior. Furthermore, our approach may inform the development of population-level agent-based models of health behavior that aim to incorporate psychological theory into models of population dynamics.

  20. The theory of reasoned action as parallel constraint satisfaction: towards a dynamic computational model of health behavior.

    Science.gov (United States)

    Orr, Mark G; Thrush, Roxanne; Plaut, David C

    2013-01-01

    The reasoned action approach, although ubiquitous in health behavior theory (e.g., Theory of Reasoned Action/Planned Behavior), does not adequately address two key dynamical aspects of health behavior: learning and the effect of immediate social context (i.e., social influence). To remedy this, we put forth a computational implementation of the Theory of Reasoned Action (TRA) using artificial-neural networks. Our model re-conceptualized behavioral intention as arising from a dynamic constraint satisfaction mechanism among a set of beliefs. In two simulations, we show that constraint satisfaction can simultaneously incorporate the effects of past experience (via learning) with the effects of immediate social context to yield behavioral intention, i.e., intention is dynamically constructed from both an individual's pre-existing belief structure and the beliefs of others in the individual's social context. In a third simulation, we illustrate the predictive ability of the model with respect to empirically derived behavioral intention. As the first known computational model of health behavior, it represents a significant advance in theory towards understanding the dynamics of health behavior. Furthermore, our approach may inform the development of population-level agent-based models of health behavior that aim to incorporate psychological theory into models of population dynamics.

  1. The theory of reasoned action as parallel constraint satisfaction: towards a dynamic computational model of health behavior.

    Science.gov (United States)

    Orr, Mark G; Thrush, Roxanne; Plaut, David C

    2013-01-01

    The reasoned action approach, although ubiquitous in health behavior theory (e.g., Theory of Reasoned Action/Planned Behavior), does not adequately address two key dynamical aspects of health behavior: learning and the effect of immediate social context (i.e., social influence). To remedy this, we put forth a computational implementation of the Theory of Reasoned Action (TRA) using artificial-neural networks. Our model re-conceptualized behavioral intention as arising from a dynamic constraint satisfaction mechanism among a set of beliefs. In two simulations, we show that constraint satisfaction can simultaneously incorporate the effects of past experience (via learning) with the effects of immediate social context to yield behavioral intention, i.e., intention is dynamically constructed from both an individual's pre-existing belief structure and the beliefs of others in the individual's social context. In a third simulation, we illustrate the predictive ability of the model with respect to empirically derived behavioral intention. As the first known computational model of health behavior, it represents a significant advance in theory towards understanding the dynamics of health behavior. Furthermore, our approach may inform the development of population-level agent-based models of health behavior that aim to incorporate psychological theory into models of population dynamics. PMID:23671603

  2. Intrinsic and extrinsic motivation as predictors of work effort: the moderating role of achievement goals.

    Science.gov (United States)

    Dysvik, Anders; Kuvaas, Bård

    2013-09-01

    This research explored the roles of intrinsic motivation (IM) and extrinsic motivation (EM) and the 2 × 2 model of achievement goals as predictors of increased work effort (WE). A cross-lagged field study was conducted among 1,441 employees from three large Norwegian service organizations across a 10-month time span. The results showed that the relationship between IM and increased WE was more positive for employees with high levels of mastery-approach goals. This observation suggests that having congruent goals may accentuate the positive relationship between IM and WE. PMID:22273179

  3. Meningoradiculitis due to borreliosis presenting as low back pain only

    International Nuclear Information System (INIS)

    We report a child with Borrelia burgdorferi meningoradiculitis. This entity, also known as Bannwarth syndrome, is rare and its presentation with low back pain only is even more unusual. The MRI findings can suggest the diagnosis. (orig.)

  4. Site controlled InAs quantum dots with ultra low densities and improved spectral uniformity

    International Nuclear Information System (INIS)

    In order to exploit InAs Quantum Dots (QDs) coupled to microcavities as single photon sources in a scalable manner one needs to know the exact position of the QD for device alignment. To improve the yield of spectrally resonant devices without adjusting the resonator geometry to the individual QD emission wavelength it is necessary to reduce spectral inhomogeneities in the ensemble emission of the QD array. The position control of our site controlled QDs (SCQDs) is maintained by directing the QD nucleation to shallow etched nanoholes on a (1,0,0)GaAs surface. To achieve a reasonably low single QD linewidth and ensemble broadening, growth parameters during the molecular beam epitaxy (MBE) deposition step of the QDs have been optimized and investigated. We have monitored the influence of the substrate temperature during SCQD growth as an important parameter for spectral homogeneity and achieved accurate QD nucleation of single SCQDs on pitches up to 4 μm on both uncapped and buried SCQDs.

  5. When will is not the same as should: The role of modals in reasoning with legal conditionals.

    Science.gov (United States)

    Gazzo Castañeda, Lupita Estefania; Knauff, Markus

    2016-01-01

    Naïve reasoners reject logically valid conclusions from conditional rules if they can think of exceptions in which the antecedent is true, but the consequent is not. However, when reasoning with legal conditionals (e.g., "If a person kills another human, then this person should be punished for manslaughter") people hardly consider exceptions but evaluate conclusions depending on their own sense of justice. We show that participants' reluctance to consider exceptions in legal reasoning depends on the modal auxiliary used. In two experiments we phrased legal conditionals either with the modal "should" (i.e., " . . . then this person should be punished"), or with "will" (i.e., " . . . then this person will be punished") and presented them as modus ponens or modus tollens inferences. Participants had to decide whether the offender should or will be punished (modus ponens) or whether the offender indeed committed the offence (modus tollens). For modus ponens inferences phrased with "should" we replicate previous findings showing that participants select conclusions on the basis of their own sense of justice (Experiments 1 and 2). Yet, when the legal conditional is phrased with the modal "will" this effect is attenuated (Experiments 1 and 2), and exceptions are considered (Experiment 1). The modal auxiliary did not affect modus tollens inferences. PMID:26292145

  6. Racial-ethnic identity in mid-adolescence: content and change as predictors of academic achievement.

    Science.gov (United States)

    Altschul, Inna; Oyserman, Daphna; Bybee, Deborah

    2006-01-01

    Three aspects of racial-ethnic identity (REI)-feeling connected to one's racial-ethnic group (Connectedness), being aware that others may not value the in-group (Awareness of Racism), and feeling that one's in-group is characterized by academic attainment (Embedded Achievement)-were hypothesized to promote academic achievement. Youth randomly selected from 3 low-income, urban schools (n=98 African American, n=41 Latino) reported on their REI 4 times over 2 school years. Hierarchical linear modeling shows a small increase in REI and the predicted REI-grades relationship. Youth high in both REI Connectedness and Embedded Achievement attained better grade point average (GPA) at each point in time; youth high in REI Connectedness and Awareness of Racism at the beginning of 8th grade attained better GPA through 9th grade. Effects are not moderated by race-ethnicity. PMID:16999790

  7. Carbon nanotubes as vectors for gene therapy: past achievements, present challenges and future goals.

    Science.gov (United States)

    Bates, Katie; Kostarelos, Kostas

    2013-12-01

    Promising therapeutic and prophylactic effects have been achieved following advances in the gene therapy research arena, giving birth to the new generation of disease-modifying therapeutics. The greatest challenge that gene therapy vectors still face is the ability to deliver sufficient genetic payloads in order to enable efficient gene transfer into target cells. A wide variety of viral and non-viral gene therapy vectors have been developed and explored over the past 10years, including carbon nanotubes. In this review we will address the application of carbon nanotubes as non-viral vectors in gene therapy with the aim to give a perspective on the past achievements, present challenges and future goals. A series of important topics concerning carbon nanotubes as gene therapy vectors will be addressed, including the benefits that carbon nanotubes offer over other non-viral delivery systems. Furthermore, a perspective is given on what the ideal genetic cargo to deliver using carbon nanotubes is and finally the geno-pharmacological impact of carbon nanotube-mediated gene therapy is discussed.

  8. Corporate Governance as a Crucial Factor in Achieving Sustainable Corporate Performance

    Directory of Open Access Journals (Sweden)

    Julija Bistrova

    2014-06-01

    Full Text Available In the developed stock markets the corporate governance aspect is crucial in the stock portfolio selection process for investor seeking to achieve shareholder value sustainability. In the emerging markets the importance of the corporate governance role just starts to be realized by the investors and by the corporate managers. The present research, looking at the stock performance leaders and laggards, analyzes whether the corporate governance system matters to achieve long-term shareholder value within the Central and Eastern European stock markets universe. Corporate governance quality was assessed and compared among the out- and underperformers. The financial results plausibility and the ownership structure were considered as well. Additionally, the authors analyzed whether the quality of corporate governance influences the economic performance of the company. The obtained results provide the proof that the corporate governance does matter as the market outperformers have above average corporate governance quality and provide trustworthy financial results more often than the underperforming companies. Besides, well-governed companies are also able to deliver more attractive financial results.

  9. Economic costs of achieving current conservation goals in the future as climate changes.

    Science.gov (United States)

    Shaw, M Rebecca; Klausmeyer, Kirk; Cameron, D Richard; Mackenzie, Jason; Roehrdanz, Patrick

    2012-06-01

    Conservation of biologically diverse regions has thus far been accomplished largely through the establishment and maintenance of protected areas. Climate change is expected to shift climate space of many species outside existing reserve boundaries. We used climate-envelope models to examine shifts in climate space of 11 species that are representative of the Mount Hamilton Project area (MHPA) (California, U.S.A.), which includes areas within Alameda, Santa Clara, San Joaquin, Stanislaus, Merced, and San Benito counties and is in the state's Central Coast ecoregion. We used Marxan site-selection software to determine the minimum area required as climate changes to achieve a baseline conservation goal equal to 80% of existing climate space for all species in the MHPA through 2050 and 2100. Additionally, we assessed the costs associated with use of existing conservation strategies (land acquisition and management actions such as species translocation, monitoring, and captive breeding) necessary to meet current species-conservation goals as climate changes. Meeting conservation goals as climate changes through 2050 required an additional 256,000 ha (332%) of protected area, primarily to the south and west of the MHPA. Through 2050 the total cost of land acquisition and management was estimated at US$1.67-1.79 billion, or 139-149% of the cost of achieving the same conservation goals with no climate change. To maintain 80% of climate space through 2100 required nearly 380,000 additional hectares that would cost $2.46-2.62 billion, or 209-219% of the cost of achieving the same conservation goals with no climate change. Furthermore, maintaining 80% of existing climate space within California for 27% of the focal species was not possible by 2100 because climate space for these species did not exist in the state. The high costs of conserving species as the climate changes-that we found in an assessment of one conservation project-highlights the need for tools that will aid

  10. Low Density Self-Assembled InAs/GaAs Quantum Dots Grown by Metal Organic Chemical Vapour Deposition

    Institute of Scientific and Technical Information of China (English)

    LI Lin; LIU Guo-Jun; WANG Xiao-Hua; LI Mei; LI Zhan-Guo; WAN Chun-Ming

    2008-01-01

    The serf-assembled InAs quantum dots (QDs) on GaAs substrates with low density (5×108cm-2) are achieved using relatively higher growth temperature and low InAs coverage by low-pressure metal-organic chemical vapour deposition.The macro-PL spectra exhibit three emission peaks at 1361,1280 and 1204nm,corresponding to the ground level (GS),the first excited state (ES1) and the second excited state (ES2) of the QDs,respectively,which are obtained when the GaAs capping layer/s grown using triethylgallium and tertiallybutylarsine.As a result of micro-PL,only a few peaks from individual dots have been observed.The exciton-biexciton behaviour was clearly observed at low temperature.

  11. Anti-idiotypic antibodies as cancer vaccines: achievements and future improvements

    Directory of Open Access Journals (Sweden)

    Maha Zohra eLadjemi

    2012-11-01

    Full Text Available Since the discovery of tumor-associated antigens (TAA, researchers have tried to develop immune-based anti-cancer therapies. Thanks to their specificity, monoclonal antibodies (mAbs offer the major advantage to induce fewer side effects than those caused by non-specific conventional treatments (eg. chemotherapy, radiotherapy. Passive immunotherapy by means of mAbs or cytokines has proved efficacy in oncology and validated the use of immune-based agents as part of anti-cancer treatment options. The next step was to try to induce an active immune protection aiming to boost own’s host immune defense against TAAs. Cancer vaccines are thus developed to specifically induce active immune protection targeting only tumor cells while preserving normal tissues from a non-specific toxicity. But, as most of TAAs are self antigens, an immune tolerance against them exists representing a barrier to effective vaccination against these oncoproteins. One promising approach to break this immune tolerance consists in the use of anti-idiotypic mAbs, so called Ab2, as antigen surrogates. This vaccination strategy allows also immunization against non-proteic antigens (such as carbohydrates. In some clinical studies, anti-idiotypic (anti-Id cancer vaccines indeed induced efficient humoral and/or cellular immune responses associated with clinical benefit.This review article will focus on recent achievements of anti-Id mAbs use as cancer vaccines in solid tumors.

  12. Gene cuisine or Frankenfood? The theory of reasoned action as an audience segmentation strategy for messages about genetically modified foods.

    Science.gov (United States)

    Silk, Kami J; Weiner, Judith; Parrott, Roxanne L

    2005-12-01

    Genetically modified (GM) foods are currently a controversial topic about which the lay public in the United States knows little. Formative research has demonstrated that the lay public is uncertain and concerned about GM foods. This study (N = 858) extends focus group research by using the Theory of Reasoned Action (TRA) to examine attitudes and subjective norms related to GM foods as a theoretical strategy for audience segmentation. A hierarchical cluster analysis revealed four unique audiences based on their attitude and subjective norm toward GM foods (ambivalent-biotech, antibiotech, biotech-normer, and biotech individual). Results are discussed in terms of the theoretical and practical significance for audience segmentation.

  13. Case-Based Reasoning as a Heuristic Selector in a Hyper-Heuristic for Course Timetabling Problems

    OpenAIRE

    Petrovic, Sanja; Qu, Rong

    2002-01-01

    This paper studies Knowledge Discovery (KD) using Tabu Search and Hill Climbing within Case-Based Reasoning (CBR) as a hyper-heuristic method for course timetabling problems. The aim of the hyper-heuristic is to choose the best heuristic(s) for given timetabling problems according to the knowledge stored in the case base. KD in CBR is a 2-stage iterative process on both case representation and the case base. Experimental results are analysed and related research issues for future work are dis...

  14. The design and implementation of an Interactive Computerised Decision Support Framework (ICDSF) as a strategy to improve nursing students' clinical reasoning skills.

    Science.gov (United States)

    Hoffman, Kerry; Dempsey, Jennifer; Levett-Jones, Tracy; Noble, Danielle; Hickey, Noelene; Jeong, Sarah; Hunter, Sharyn; Norton, Carol

    2011-08-01

    This paper describes the conceptual design and testing of an Interactive Computerised Decision Support Framework (ICDSF) which was constructed to enable student nurses to "think like a nurse." The ICDSF was based on a model of clinical reasoning. Teaching student nurses to reason clinically is important as poor clinical reasoning skills can lead to "failure-to rescue" of deteriorating patients. The framework of the ICDSF was based on nursing concepts to encourage deep learning and transferability of knowledge. The principles of active student participation, situated cognition to solve problems, authenticity, and cognitive rehearsal were used to develop the ICDSF. The ICDSF was designed in such a way that students moved through it in a step-wise fashion and were required to achieve competency at each step before proceeding to the next. The quality of the ICDSF was evaluated using a questionairre survey, students' written comments and student assessment measures on a pilot and the ICDSF. Overall students were highly satisfied with the clinical scenarios of the ICDSF and believed they were an interesting and useful way to engage in authentic clinical learning. They also believed the ICDSF was useful in developing cognitive skills such as clinical reasoning, problem-solving and decision-making. Some reported issues were the need for good technical support and the lack of face to face contact when using e-learning. Some students also believed the ICDSF was less useful than actual clinical placements. PMID:21074299

  15. Italy as the Cradle of the Renaissance:From the Perspective of Its Partic-ular Reasons

    Institute of Scientific and Technical Information of China (English)

    HUANG Mei

    2015-01-01

    The Renaissance is a period from the 14th to the 17th centuries, considered as a shift from Middle Ages to Modern times of European history. It developed from Middle Ages which laid its political, economical, cultural and social foundation. Owing to the development of capitalist production relations in Europe during the late Middle Ages, bourgeoisie initiated this cultural movement whose essence is humanism as a fight against feudalism.The Renaissance originated in the form of a cultural movement from Italy in the 14th century and swept over the whole Europe. Apart from the common factors contributing to this movement, the peculiar reasons why Italy became the bellwether of this essential cultural movement are as follows:direct inherit of ancient Roman tradi⁃tion, the favorable geographical position, the unparalleled cities with the development of commerce, city republics and secularism.

  16. Reasons for Low Levels of Interactivity

    DEFF Research Database (Denmark)

    Etter, Michael

    2013-01-01

    The interactivity levels of online CSR communication are typically low. This study explores the reasons for the low levels of interactivity in the popular social media tool Twitter. An analysis of 41,864 Twitter messages (tweets) from the thirty most central corporate accounts in a CSR Twitter...... network is conducted. Comparisons (t-test) between CSR tweets and general tweets and between specialized CSR Twitter accounts and general accounts reveal that the low levels of interactivity are due to a reactive interaction approach and a lack of specialization....

  17. The Importance of Identity Development, Principled Moral Reasoning, and Empathy as Predictors of Openness to Diversity in Emerging Adults

    Directory of Open Access Journals (Sweden)

    Marylie W. Gerson

    2014-10-01

    Full Text Available Programs that attempt to increase tolerance and openness to diverse cultures, religions, and ethnicities through education and exposure are popular and often successful in higher education, but at times backfire, leading instead to an increase in prejudice. The present study considered several intrapersonal and developmental factors that may be important to consider. Identity development (Measures of Psychosocial Development, based on Erikson’s theory of psychosocial development, moral reasoning (Defining Issues Test, based on Kohlberg’s theory of moral development, and empathy (a subscale of the California Personality Inventory were tested as predictors of openness to diversity (Miville-Guzman Universality-Diversity Scale with entering first-year university students (n = 282 at a small, private comprehensive university. As hypothesized, identity development, principled moral reasoning, and empathy each significantly and positively predicted openness to diversity, and the combination of predictors accounted for a moderately large portion of the criterion’s variance. Implications are discussed for developing effective programs to facilitate openness to diversity in emerging adulthood.

  18. The importance of safety in achieving the widespread use of hydrogen as a fuel

    Energy Technology Data Exchange (ETDEWEB)

    Edeskuty, F.J.

    1997-09-01

    The advantages of hydrogen fuel have been adequately demonstrated on numerous occasions. However, two major disadvantages have prevented any significant amount of corresponding development. These disadvantages have been in the economics of producing sufficient quantities of hydrogen and in the safety (both real and perceived) of its use. To date work has mostly been properly centered on solving the economic problems. However, a greater effort on the safety of new hydrogen systems now being proposed also deserves consideration. To achieve the greatest safety in the expansion of the use of hydrogen into its wide-spread use as a fuel, attention must be given to four considerations. These are, obtaining knowledge of all the physical principles involved in the new uses, having in place the regulations that allow the safe interfacing of the new systems, designing and constructing the new systems with safety in mind, and the training of the large number of people that will become the handlers of the hydrogen. Existing organizations that produce, transport, or use hydrogen on a large scale have an excellent safety record. This safety record comes as a consequence of dedicated attention to the above-mentioned principles. However, where these principles were not closely followed, accidents have resulted. Some examples can be cited. As the use of hydrogen becomes more widespread, there must be a mechanism for assuring the universal application of these principles. Larger and more numerous fleet operations with hydrogen fuel may be the best way to begin the indoctrination of the general public to the more general use of hydrogen fuel. Demonstrated safe operation with hydrogen is vital to its final acceptance as the fuel of choice.

  19. Achieving 90–90–90 in paediatric HIV: adolescence as the touchstone for transition success

    Directory of Open Access Journals (Sweden)

    Sonia Lee

    2015-12-01

    Full Text Available Introduction: The number of children less than 15 years estimated to be living with HIV globally approximated 3.2 million in 2013. Young people aged 15 to 24 years living with HIV approximated 4 million. The survival of these children and adolescents into adulthood poses new and urgent challenges of transition from the paediatric to adolescent to adult healthcare settings due to emerging developmental, psychosocial and comorbid issues. In order to achieve treatment targets of 90–90–90 across the continuum of care for paediatric HIV by 2020, focused efforts on the implementation of appropriate healthcare transition plans across the lifespan, with a focus on adolescence, should be prioritized. Discussion: Published data or empirical evidence examining implementation of transition models and association with clinical outcomes are limited. While some guidelines do exist that offer recommendations about how to promote seamless transitions, very few data are available to assess the adequacy of these guidelines and whether they are effectively adhered to in clinical care settings globally. Furthermore, paediatric and adolescent HIV infection, either acquired perinatally or behaviourally, is set apart from other chronic illnesses as a highly stigmatizing disease that disproportionately affects poor, minority and often marginalized populations. Focused efforts on adolescence as the touchstone for transition practices and policies need to be implemented. Conclusions: Optimal healthcare for these vulnerable populations, particularly in resource-limited settings, will require HIV-specific transitional care services and programmes that are coordinated, collaborative, integrated and, importantly, evidence-based.

  20. Low Test Anxiety as a Potential Indicator of Underachievement

    Science.gov (United States)

    Wittmaier, Bruce C.

    1976-01-01

    Compared with high-test anxious students, those with low scores on both scales of the Achievement Anxiety Test were less anxious before a test, studied less for it, and got more sleep the night before. The pattern of results was congruent with expectations. (Author)

  1. Meningoradiculitis due to borreliosis presenting as low back pain only

    Energy Technology Data Exchange (ETDEWEB)

    Demaerel, P.; Crevits, I.; Baert, A.L. [Department of Radiology, University Hospitals, Leuven (Belgium); Casteels-Van Daele, M. [Department of Paediatrics, University Hospitals, Leuven (Belgium)

    1998-02-01

    We report a child with Borrelia burgdorferi meningoradiculitis. This entity, also known as Bannwarth syndrome, is rare and its presentation with low back pain only is even more unusual. The MRI findings can suggest the diagnosis. (orig.) With 1 fig., 3 refs.

  2. The ground state properties of In(Ga)As/GaAs low strain quantum dots

    Science.gov (United States)

    Pieczarka, Maciej; Sęk, Grzegorz

    2016-08-01

    We present theoretical studies on the confined states in low-strain In(Ga)As quantum dots (QDs). The 8-band k·p model together with the continuum elasticity theory and piezoelectric fields were employed to calculate the potential and confined electron and hole eigenstates. We focused on low-indium-content QDs with distinct in-plane asymmetry, which are naturally formed in the low strain regime of the Stranski-Krastanow growth mode. It has been found that the naturally thick wetting layer together with piezoelectric potential affect the total confinement potential to such extent that the hole eigenstates can get the spatial in-plane orientation orthogonal to the main axis of the dot elongation. This can influence both, qualitatively and quantitatively, many of the electronic and optical properties, as e.g. the polarization selection rules for the optical transition or the transitions oscillator strength. Eventually, importance of the degree of the shape asymmetry or the dots' size, and differences between the low-strain (low-In-content) QDs and pure InAs dots formed in high strain conditions are discussed.

  3. Defect studies in low-temperature-grown GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Bliss, D.E.

    1992-11-01

    High content of excess As is incorporated in GaAs grown by low-temperature molecular-beam-epitaxy (LTMBE). The excess As exists primarily as As antisite defects AsGa and a lesser extent of gallium vacancies V[sub Ga]. The neutral AsGa-related defects were measured by infrared absorption at 1[mu]m. Gallium vacancies, V[sub Ga], was investigated by slow positron annihilation. Dependence of defect contents on doping was studied by Si and Be dopants. No free carriers are generated by n-type or p-type doping up to 10[sup 19] cm[sup [minus]3] Si or Be. Raman data indicate Be occupies Ga substitutional sites but Si atom is not substitutional. Si induces more As[sub Ga] in the layer. As As[sub Ga] increases, photoquenchable As[sub Ga] decreases. Fraction of photoquenchable defects correlates to defects within 3 nearest neighbor separations disrupting the metastability. Annealing reduces neutral As[sub Ga] content around 500C, similar to irradiation damaged and plastically deformed Ga[sub As], as opposed to bulk grown GaAs in which As[sub Ga]-related defects are stable up to 1100C. The lower temperature defect removal is due to V[sub Ga] enhanced diffusion of As[sub Ga] to As precipitates. The supersaturated V[sub GA] and also decreases during annealing. Annealing kinetics for As[sub Ga]-related defects gives 2.0 [plus minus] 0.3 eV and 1.5 [plus minus] 0.3 eV migration enthalpies for the As[sub Ga] and V[sub Ga]. This represents the difference between Ga and As atoms hopping into the vacancy. The non-photoquenchable As[sub Ga]-related defects anneal with an activation energy of 1.1 [plus minus] 0.3eV. Be acceptors can be activated by 800C annealing. Temperature difference between defect annealing and Be activation formation of As[sub Ga]-Be[sub Ga] pairs. Si donors can only be partially activated.

  4. Defect studies in low-temperature-grown GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Bliss, D.E.

    1992-11-01

    High content of excess As is incorporated in GaAs grown by low-temperature molecular-beam-epitaxy (LTMBE). The excess As exists primarily as As antisite defects AsGa and a lesser extent of gallium vacancies V{sub Ga}. The neutral AsGa-related defects were measured by infrared absorption at 1{mu}m. Gallium vacancies, V{sub Ga}, was investigated by slow positron annihilation. Dependence of defect contents on doping was studied by Si and Be dopants. No free carriers are generated by n-type or p-type doping up to 10{sup 19} cm{sup {minus}3} Si or Be. Raman data indicate Be occupies Ga substitutional sites but Si atom is not substitutional. Si induces more As{sub Ga} in the layer. As As{sub Ga} increases, photoquenchable As{sub Ga} decreases. Fraction of photoquenchable defects correlates to defects within 3 nearest neighbor separations disrupting the metastability. Annealing reduces neutral As{sub Ga} content around 500C, similar to irradiation damaged and plastically deformed Ga{sub As}, as opposed to bulk grown GaAs in which As{sub Ga}-related defects are stable up to 1100C. The lower temperature defect removal is due to V{sub Ga} enhanced diffusion of As{sub Ga} to As precipitates. The supersaturated V{sub GA} and also decreases during annealing. Annealing kinetics for As{sub Ga}-related defects gives 2.0 {plus_minus} 0.3 eV and 1.5 {plus_minus} 0.3 eV migration enthalpies for the As{sub Ga} and V{sub Ga}. This represents the difference between Ga and As atoms hopping into the vacancy. The non-photoquenchable As{sub Ga}-related defects anneal with an activation energy of 1.1 {plus_minus} 0.3eV. Be acceptors can be activated by 800C annealing. Temperature difference between defect annealing and Be activation formation of As{sub Ga}-Be{sub Ga} pairs. Si donors can only be partially activated.

  5. Facilitating progress in health behaviour theory development and modification: the reasoned action approach as a case study.

    Science.gov (United States)

    Head, Katharine J; Noar, Seth M

    2014-01-01

    This paper explores the question: what are barriers to health behaviour theory development and modification, and what potential solutions can be proposed? Using the reasoned action approach (RAA) as a case study, four areas of theory development were examined: (1) the theoretical domain of a theory; (2) tension between generalisability and utility, (3) criteria for adding/removing variables in a theory, and (4) organisational tracking of theoretical developments and formal changes to theory. Based on a discussion of these four issues, recommendations for theory development are presented, including: (1) the theoretical domain for theories such as RAA should be clarified; (2) when there is tension between generalisability and utility, utility should be given preference given the applied nature of the health behaviour field; (3) variables should be formally removed/amended/added to a theory based on their performance across multiple studies and (4) organisations and researchers with a stake in particular health areas may be best suited for tracking the literature on behaviour-specific theories and making refinements to theory, based on a consensus approach. Overall, enhancing research in this area can provide important insights for more accurately understanding health behaviours and thus producing work that leads to more effective health behaviour change interventions.

  6. Facilitating progress in health behaviour theory development and modification: the reasoned action approach as a case study.

    Science.gov (United States)

    Head, Katharine J; Noar, Seth M

    2014-01-01

    This paper explores the question: what are barriers to health behaviour theory development and modification, and what potential solutions can be proposed? Using the reasoned action approach (RAA) as a case study, four areas of theory development were examined: (1) the theoretical domain of a theory; (2) tension between generalisability and utility, (3) criteria for adding/removing variables in a theory, and (4) organisational tracking of theoretical developments and formal changes to theory. Based on a discussion of these four issues, recommendations for theory development are presented, including: (1) the theoretical domain for theories such as RAA should be clarified; (2) when there is tension between generalisability and utility, utility should be given preference given the applied nature of the health behaviour field; (3) variables should be formally removed/amended/added to a theory based on their performance across multiple studies and (4) organisations and researchers with a stake in particular health areas may be best suited for tracking the literature on behaviour-specific theories and making refinements to theory, based on a consensus approach. Overall, enhancing research in this area can provide important insights for more accurately understanding health behaviours and thus producing work that leads to more effective health behaviour change interventions. PMID:25053006

  7. The Interview as Collaborative Achievement: Interaction, Identity, and Ideology in a Speech Event

    Science.gov (United States)

    Talmy, Steven

    2011-01-01

    This article contrasts a common conceptualization of the interview in applied linguistics, referred to as an "interview as research instrument" perspective, with an alternative, referred to as a "research interview as social practice" orientation. It illustrates implications of the two perspectives on interviews by contrasting a thematic analysis…

  8. High-Power and Low-Threshold-Current-Density GaAs/AlGaAs Quantum Cascade Lasers

    Institute of Scientific and Technical Information of China (English)

    LIU Jun-Qi; LIU Feng-Qi; LI Lu; SHAO Ye; GUO Yu; WANG Zhan-Guo

    2006-01-01

    @@ We report on the realization of GaAs/AlGaAs quantum cascade lasers with an emission wavelength of 9.1 μm above the liquid nitrogen temperature. With optimal current injection window and ridge width of 24 and 60μm respectively, a peak output power more than 500mW is achieved in pulsed mode operation. A low threshold current density Jth = 2.6 kA/cm2 gives the devices good lasing characteristics. In a drive frequency of 1 kHz, the laser operates up to 20% duty cycle.

  9. Using the Achieving Success Everyday (ASE) Group Model to Promote Self-Esteem and Academic Achievement for English as a Second Language (ESL) Students

    Science.gov (United States)

    Shi, Qi; Steen, Sam

    2012-01-01

    The Achieving Success Everyday (ASE) group model is used to promote self-esteem and academic performance of English as a second language (ESL) students. The findings from the preliminary data indicated that the participants' self-esteem was significantly improved after participation in the group. There was no significant improvement in the total…

  10. Academic Achievement as a Moderator of Genetic Influences on Alcohol Use in Adolescence

    Science.gov (United States)

    Benner, Aprile D.; Kretsch, Natalie; Harden, K. Paige; Crosnoe, Robert

    2014-01-01

    Prior research suggests a link between academic performance and alcohol use during adolescence, but the degree to which this association reflects actual protective effects continues to be debated. We investigated the role of genetic factors in the association between academic achievement and adolescent alcohol use and whether achievement might…

  11. Student Achievement Data and Findings, as Reported in Math and Science Partnerships' Annual and Evaluation Reports

    Science.gov (United States)

    Yin, Robert K.

    2009-01-01

    A primary feature of the Math and Science Partnership Program Evaluation (MSP PE) is the examination of K-12 student achievement changes associated with the National Science Foundation's (NSF) Math and Science Partnership (MSP) Program. This article describes one of three complementary assessments of K-12 student achievement being conducted by the…

  12. Self-Beliefs and Behavioural Development as Related to Academic Achievement in Canadian Aboriginal Children

    Science.gov (United States)

    Baydala, Lola; Rasmussen, Carmen; Birch, June; Sherman, Jody; Wikman, Erik; Charchun, Julianna; Kennedy, Merle; Bisanz, Jeffrey

    2009-01-01

    The authors explored the relationship between measures of self-belief, behavioural development, and academic achievement in Canadian Aboriginal children. Standardized measures of intelligence are unable to consistently predict academic achievement in students from indigenous populations. Exploring alternative factors that may be both predictive…

  13. Affective variables as predictors of biology achievement: A study on 11th grade students

    OpenAIRE

    Alpmen Ayten

    2016-01-01

    The purpose of this study was to examine the contribution of the gender, self-efficacy beliefs, task value, and learning strategies to the 11th grade students’ biology achievement. A total of 1035 students from different high schools in Yenimahalle and Çankaya districts of Ankara participated in the study. The Motivated Strategies for Learning Questionnaire [21], (MSLQ) and Biology Achievement Test (BAT) were used to collect data. Results of the the simultaneous multiple regression analysis i...

  14. Parental participation in a chapter I parent center as a predictor of academic achievement

    OpenAIRE

    Johnson, Barbara Ann Lawrence

    1990-01-01

    This study was designed to examine the relationship of participation in the Chapter I Parent Center to four of the variables often associated with academic achievement namely: (1) the child's home environment; (2) parental attitude towards education; (3) the child's self-concept; and (4) the child's motivation to learn. In addition, the study examines the relationship between participation in the Chapter I Parent Center program and reading achievement. The basic objective of th...

  15. Corporate Governance as a Crucial Factor in Achieving Sustainable Corporate Performance

    OpenAIRE

    Julija Bistrova; Natalja Lace; Manuela Tvaronaviciene

    2014-01-01

    In the developed stock markets the corporate governance aspect is crucial in the stock portfolio selection process for investor seeking to achieve shareholder value sustainability. In the emerging markets the importance of the corporate governance role just starts to be realized by the investors and by the corporate managers. The present research, looking at the stock performance leaders and laggards, analyzes whether the corporate governance system matters to achieve long-term shareholder va...

  16. Intelligence And Self-concept As Co-relates Of Academic Achievement

    OpenAIRE

    Paramjeet Singh Bhadwal; Darshana Sharma

    2012-01-01

    The main purpose of this study is to explore the correlation between intelligence and academic achievement, self-concept and academic achievement among high school students in Jammu city. Two hundred-fifty five students (ninth graders) participated in this study. 142 of whom were female students and 113 were male students. Pearson's Product Moment Coefficient of Correlation was employed for data analysis. Results indicated that there was significant positive relationship bet...

  17. Time-dependent Networks as Models to Achieve Fast Exact Time-table Queries

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Jacob, Rico

    2001-01-01

    We consider efficient algorithms for exact time-table queries, i.e. algorithms that find optimal itineraries. We propose to use time-dependent networks as a model and show advantages of this approach over space-time networks as models....

  18. Time-Dependent Networks as Models to Achieve Fast Exact Time-Table Queries

    DEFF Research Database (Denmark)

    Brodal, Gert Stølting; Jacob, Rico

    2003-01-01

    We consider efficient algorithms for exact time-table queries, i.e. algorithms that find optimal itineraries for travelers using a train system. We propose to use time-dependent networks as a model and show advantages of this approach over space-time networks as models....

  19. Beyond Virtual Equality: Liberatory Consciousness as a Path to Achieve Trans* Inclusion in Higher Education

    Science.gov (United States)

    Catalano, D. Chase J.

    2015-01-01

    Trans* men have not, as yet, received specific research attention in higher education. Based on intensive interviews with 25 trans* men enrolled in colleges or universities in New England, I explore their experiences in higher education. I analyze participants' descriptions of supports and challenges in their collegiate environments, as well as…

  20. The Achievement Flow Motive as an Element of the Autotelic Personality: Predicting Educational Attainment in Three Cultures

    Science.gov (United States)

    Busch, Holger; Hofer, Jan; Chasiotis, Athanasios; Campos, Domingo

    2013-01-01

    Human behavior is directed by an implicit and an explicit motivational system. The intrinsic form of the implicit achievement motive has been demonstrated to predict the experience of flow. Thus, this achievement flow motive can be considered an integral component of the autotelic personality, posited in Flow Theory as dispositional difference in…

  1. Strategic planning as a tool for achieving alignment in academic health centers.

    Science.gov (United States)

    Higginbotham, Eve J; Church, Kathryn C

    2012-01-01

    After the passage of the Patient Protection and Affordable Care Act in March 2010, there is an urgent need for medical schools, teaching hospitals, and practice plans to work together seamlessly across a common mission. Although there is agreement that there should be greater coordination of initiatives and resources, there is little guidance in the literature to address the method to achieve the necessary transformation. Traditional approaches to strategic planning often engage a few leaders and produce a set of immeasurable initiatives. A nontraditional approach, consisting of a Whole-Scale (Dannemiller Tyson Associates, Ann Arbor, MI) engagement, appreciative inquiry, and a balanced scorecard can, more rapidly transform an academic health center. Using this nontraditional approach to strategic planning, increased organizational awareness was achieved in a single academic health center. Strategic planning can be an effective tool to achieve alignment, enhance accountability, and a first step in meeting the demands of the new landscape of healthcare. PMID:23303997

  2. Strategic planning as a tool for achieving alignment in academic health centers.

    Science.gov (United States)

    Higginbotham, Eve J; Church, Kathryn C

    2012-01-01

    After the passage of the Patient Protection and Affordable Care Act in March 2010, there is an urgent need for medical schools, teaching hospitals, and practice plans to work together seamlessly across a common mission. Although there is agreement that there should be greater coordination of initiatives and resources, there is little guidance in the literature to address the method to achieve the necessary transformation. Traditional approaches to strategic planning often engage a few leaders and produce a set of immeasurable initiatives. A nontraditional approach, consisting of a Whole-Scale (Dannemiller Tyson Associates, Ann Arbor, MI) engagement, appreciative inquiry, and a balanced scorecard can, more rapidly transform an academic health center. Using this nontraditional approach to strategic planning, increased organizational awareness was achieved in a single academic health center. Strategic planning can be an effective tool to achieve alignment, enhance accountability, and a first step in meeting the demands of the new landscape of healthcare.

  3. 3D Lumped LC Resonators as Low Mass Axion Haloscopes

    CERN Document Server

    McAllister, Ben T; Tobar, Michael E

    2016-01-01

    The axion is a hypothetical particle considered to be the most economical solution to the strong CP problem. It can also be formulated as a compelling component of dark matter. The haloscope, a leading axion detection scheme, relies on the conversion of galactic halo axions into real photons inside a resonant cavity structure in the presence of a static magnetic field, where the generated photon frequency corresponds to the mass of the axion. For maximum sensitivity it is key that the central frequency of the cavity mode structure coincides with the frequency of the generated photon. As the mass of the axion is unknown, it is necessary to perform searches over a wide range of frequencies. Currently there are substantial regions of the promising pre-inflationary low mass axion range without any viable proposals for experimental searches. We show that 3D resonant LC circuits with separated magnetic and electric fields, commonly known as re-entrant cavities, can be sensitive dark matter haloscopes in this region...

  4. Low density lipoproteins as circulating fast temperature sensors.

    Directory of Open Access Journals (Sweden)

    Ruth Prassl

    Full Text Available BACKGROUND: The potential physiological significance of the nanophase transition of neutral lipids in the core of low density lipoprotein (LDL particles is dependent on whether the rate is fast enough to integrate small (+/-2 degrees C temperature changes in the blood circulation. METHODOLOGY/PRINCIPAL FINDINGS: Using sub-second, time-resolved small-angle X-ray scattering technology with synchrotron radiation, we have monitored the dynamics of structural changes within LDL, which were triggered by temperature-jumps and -drops, respectively. Our findings reveal that the melting transition is complete within less than 10 milliseconds. The freezing transition proceeds slowly with a half-time of approximately two seconds. Thus, the time period over which LDL particles reside in cooler regions of the body readily facilitates structural reorientation of the apolar core lipids. CONCLUSIONS/SIGNIFICANCE: Low density lipoproteins, the biological nanoparticles responsible for the transport of cholesterol in blood, are shown to act as intrinsic nano-thermometers, which can follow the periodic temperature changes during blood circulation. Our results demonstrate that the lipid core in LDL changes from a liquid crystalline to an oily state within fractions of seconds. This may, through the coupling to the protein structure of LDL, have important repercussions on current theories of the role of LDL in the pathogenesis of atherosclerosis.

  5. Low temperature properties of pnictide CrAs single crystal

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    High quality single crystal CrAs was grown by Sn flux method.The results of magnetic susceptibility and electrical resistivity are reported in a temperature range of 2 to 800 K.At low temperatures,a T2 dependence of resistivity is observed showing a Fermi-liquid behavior.The Kadowaki-Woods ratio is found to be 1×10-5 μΩ cm mol2 K2 mJ-2,which fits well to the universal value for many correlated electron systems.At about 270 K,a clear magnetic transition is observed with sharp changes of resistivity and susceptibility.Above 270 K,a linear-temperature dependence of the magnetic susceptibility is observed up to 700 K,which resembles the T-dependent magnetic susceptibility of parents of iron-pnictides superconductors.

  6. Intrinsic Motivation, Perceived Competence and Classroom Engagement as Longitudinal Predictors of Adolescent Reading Achievement

    Science.gov (United States)

    Froiland, John Mark; Oros, Emily

    2014-01-01

    This study investigated the effects of intrinsic motivation, perceived competence, classroom engagement and extrinsic motivation on reading development among youth. Using a nationally representative sample of students in the US, the researchers followed students longitudinally from fifth to eighth grade. Reading achievement was measured using…

  7. A History of Black Achievement as Impacted by Federal Court Decisions in the Last Century

    Science.gov (United States)

    Gooden, Mark A.

    2004-01-01

    The major decisions of pre-and post-Brown and the history of African American student achievement are discussed through an analysis of select federal court decisions. One can conclude that the struggle for equal educational opportunity for African Americans in the United States is vying for the attention of more conservative Federal Court judges.

  8. Achievement, Agency, Gender, and Socioeconomic Background as Predictors of Postschool Choices: A Multicontext Study

    Science.gov (United States)

    Parker, Philip D.; Schoon, Ingrid; Tsai, Yi-Miau; Nagy, Gabriel; Trautwein, Ulrich; Eccles, Jacquelynne S.

    2012-01-01

    In this article, the authors develop and test a differential effects model of university entry versus major selection using a set of common predictors, including background factors (gender and socioeconomic status), academic achievement, and academic self-concept. The research used data from 2 large longitudinal databases from Germany (N = 5,048)…

  9. Academic Identification as a Mediator of the Relationship between Parental Socialization and Academic Achievement

    Science.gov (United States)

    Strambler, Michael J.; Linke, Lance H.; Ward, Nadia L.

    2013-01-01

    This study examines whether academic identification, or one's psychological and emotional investment in academics, mediates the association between child-reported parental educational socialization and standardized achievement test scores among a predominantly ethnic minority sample of 367 urban middle school students. We predicted that academic…

  10. Learning Environments as Basis for Cognitive Achievements of Students in Basic Science Classrooms in Nigeria

    Science.gov (United States)

    Atomatofa, Rachel; Okoye, Nnamdi; Igwebuike, Thomas

    2016-01-01

    The nature of classroom learning environments created by teachers had been considered very important for learning to take place effectively. This study investigated the effect of creating constructivist and transmissive learning environments on achievements of science students of different ability levels. 243 students formed the entire study…

  11. Processing Speed and Intelligence as Predictors of School Achievement: Mediation or Unique Contribution?

    Science.gov (United States)

    Dodonova, Yulia A.; Dodonov, Yury S.

    2012-01-01

    The relationships between processing speed, intelligence, and school achievement were analyzed on a sample of 184 Russian 16-year-old students. Two speeded tasks required the discrimination of simple geometrical shapes and the recognition of the presented meaningless figures. Raven's Advanced Progressive Matrices and the verbal subtests of…

  12. SELF-EFFICACY BELIEFS, ACHIEVEMENT MOTIVATION AND GENDER AS RELATED TO EDUCATIONAL SOFTWARE DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Alev ATES

    2011-07-01

    Full Text Available This study aims to investigate preservice computer teachers’ self-efficacy beliefs and achievement motivation levels for educational software development before and after the “Educational Software Design, Development and Evaluation (ESDDE” course. A pretest and post test design without a control group was employed. In 2008, 46 senior students (25 male and 21 female who were enrolled at Computer Education and Instructional Technology department participated in this study.The data were collected by the scale of self-efficacy beliefs towards Educational Software Development (ESD, achievement motivation scale besides student demographics form. Positively, the results revealed that the students’ self efficacy beliefs towards educational software development significantly improved after ESDDE course. Before the course, the students’ self-efficacy beliefs were significantly different according to perceived level of programming competency and gender in favor of male, however after the course there was no significant difference in self-efficacy beliefs regarding gender and perceived level of programming competency. Hence, achievement motivation levels after the course were significantly higher than before while gender and perceived level of programming competency had no significant effect on achievement motivation for ESD. The study is considered to contribute studies investigating gender and computer related self efficacy beliefs in IT education.

  13. Work Valence as a Predictor of Academic Achievement in the Family Context

    Science.gov (United States)

    Porfeli, Erik; Ferrari, Lea; Nota, Laura

    2013-01-01

    This study asserts a theoretical model of academic and work socialization within the family setting. The presumed associations between parents' work valences, children's work valences and valence perceptions, and children's academic interest and achievement are tested. The results suggest that children's perceptions of parents…

  14. Cognitive Holding Power, Fluid Intelligence, and Mathematical Achievement as Predictors of Children's Realistic Problem Solving

    Science.gov (United States)

    Xin, Ziqiang; Zhang, Li

    2009-01-01

    The present study explored whether first and second order cognitive holding power perceived by children in mathematical classrooms, fluid intelligence, and mathematical achievement predicted their performance on standard problems, and especially realistic problems. A sample of 119 Chinese 4-6th graders were administered the word problem test, the…

  15. Educational Encouragement, Parenting Styles, Gender and Ethnicity as Predictors of Academic Achievement among Special Education Students

    Science.gov (United States)

    Khan, Aqeel; Ahmad, Roslee; Hamdan, Abdul Rahim; Mustaffa, Mohamed Sharif

    2014-01-01

    Current study examines the predictors of academic achievement: role of parenting styles, educational encouragement, gender and ethnicity among special education students. Participants of this study consisted 200 special education students (N = 105 boys and N = 95 girls) age varies 14 to 19 years from one school located at Kuala Lumpur, Malaysia.…

  16. Three functional aspects of working memory as strong predictors of early school achievements: The review and illustrative evidence

    Directory of Open Access Journals (Sweden)

    Sedek Grzegorz

    2016-04-01

    Full Text Available The paper presents an overview of research on working memory as a predictor of early school achievements. We contrast two main areas of research on the role of working memory in school achievements: the first concerns the structural model of working memory and the second focuses on executive functions. Then, we discuss the facet model of working memory as a promising approach merging the two research branches on working memory tasks as predictors of early school achievements. At the end we present exemplary results of the research conducted on a national sample of six- and seven-year-olds in Poland, which indicates strong relation of working memory functions with the measures of competences in mathematics, reading, and writing. Additionally, the mediation analyses, with parents’ education as a covariate, indicate that the influence of age on achievements in math, reading, and writing in six- and seven-year olds is mediated by working memory functions.

  17. Mathematics Achievement in High- and Low-Achieving Secondary Schools

    Science.gov (United States)

    Mohammadpour, Ebrahim; Shekarchizadeh, Ahmadreza

    2015-01-01

    This paper identifies the amount of variance in mathematics achievement in high- and low-achieving schools that can be explained by school-level factors, while controlling for student-level factors. The data were obtained from 2679 Iranian eighth graders who participated in the 2007 Trends in International Mathematics and Science Study. Of the…

  18. Online Self-Regulatory Learning Behaviors as a Mediator in the Relationship between Online Course Perceptions with Achievement

    OpenAIRE

    Valerie Paton; Lucy Barnard; William Lan

    2008-01-01

    Positive perceptions of online course communication and collaboration have been associated with better academic outcomes, while self-regulatory learning behaviors have also been linked to academic achievement and other positive learning outcomes. In the current study, we examined whether self-regulatory learning behaviors may be considered as mediating the relationship between student perceptions of online course communication and collaboration with academic achievement as measured by grade p...

  19. Big Five Personality Traits, Cognitive Appraisals and Emotion Regulation Strategies as Predictors of Achievement Emotions

    Directory of Open Access Journals (Sweden)

    Izabela Sorić

    2013-09-01

    Full Text Available In academic settings, emotions can arise in a variety of contexts and have adverse and interfering effects on learning and performance, especially those of negative valence. Thus, the investigation of their personal antecedents and different strategies implemented by students in order to regulate them, are important topics of research. The aim of this study was to examine the unique contribution of Big Five personality traits (as distal personal antecedents of emotions, cognitive control and value appraisals (as their proximal antecedents and students' tendencies to reappraise or suppress their emotions (as most important emotion regulation strategies for experiencing academic emotions of unhappiness, anger, anxiety and humiliation. The sample consisted of 500 high school students who completed the self-report questionnaire during their regular scheduled classes. The series of multiple hierarchical regression analyses showed that all groups of predictors have made significant and independent contribution to the explanation of all analysed emotions.

  20. Taste as a didactic approach: enabling students to achieve learning goals

    DEFF Research Database (Denmark)

    Wistoft, Karen; Christensen, Jacob

    2016-01-01

    and innovation in school. The method is a questionnaire among students (N= 769) who have competed in Food Fight, a competition that forms part of Food Knowledge. The connection between taste and learning is a relatively unexplored field, and the analysis in this article indicates that the experience of working...... with taste in Food Knowledge may have an effect on students’ expected learning that is equally positive – or even more so – as that of known didactic elements like student participation and innovation. Therefore, teachers need to create balance between didactic elements and remember to incorporate taste......Teaching does not necessarily condition learning, and specific didactic elements do not necessarily condition the best learning outcome; this also applies to ‘food and meal’ lessons in schools. Teachers’ didactic reflections usually reflect the content and form of the teaching, as well as a number...

  1. Achieving 90–90–90 in paediatric HIV: adolescence as the touchstone for transition success

    OpenAIRE

    Sonia Lee; Rohan Hazra

    2015-01-01

    Introduction: The number of children less than 15 years estimated to be living with HIV globally approximated 3.2 million in 2013. Young people aged 15 to 24 years living with HIV approximated 4 million. The survival of these children and adolescents into adulthood poses new and urgent challenges of transition from the paediatric to adolescent to adult healthcare settings due to emerging developmental, psychosocial and comorbid issues. In order to achieve treatment targets of 90–90–90 across ...

  2. English Language Proficiency Tests and Academic Achievement: A Study on the Malaysian University English Test as a Predictor of Technical Programme Undergraduates Academic Achievement

    Directory of Open Access Journals (Sweden)

    Nurhazlini Rahmat

    2015-02-01

    Full Text Available In the Malaysian education system, English has always played an important role. In acknowledging its importance, Malaysian University English Test (MUET has been introduced to enable continued emphasis on this role.  MUET has been made compulsory for those who wish to pursue a first degree programme in local universities. This study aims to examine the relationship between English language proficiency test (as measured by MUET bands to predict the undergraduates academic achievement (as measured by Cumulative Grade Point Average score. It also aims to determine the recommended MUET band as an entry requirement for prospective technical programme undergraduates in Universiti Putra Malaysia (UPM. The study was carried out among 225 final year undergraduates of five different faculties in UPM, namely Faculty of Engineering, Faculty of Forestry, Faculty of Biotechnology and Biomolecular, Faculty of Food Science and Technology, and Faculty of Veterinary Medicine.  The data used were obtained by administering a brief questionnaire and were quantitatively analysed using Statistical Package for Social Science (SPSS version 19.  The study revealed that there is a medium positive correlation between English language proficiency and academic achievement where students who have scored higher bands for MUET are the ones who obtained higher CGPA in their study. Based on the findings, it is recommended that UPM and other local universities make changes towards the minimum MUET entry requirement to help prospective undergraduates excel in their academic study.Keywords: English language proficiency, academic achievement, technical programme, MUET, CGPA

  3. Formal Kindergaten Experience as a Predictor of Academic Achievement of Primary Five Pupils in English Language

    Directory of Open Access Journals (Sweden)

    I.T. Eweniyi

    2012-10-01

    Full Text Available This study investigated the effect of formal kindergarten education on the achievement of primary five pupils. The academic performance of pupils with and without formal kindergarten experience were compared. Their achievement was based on their performance in the English language tests. The sample consisted of one hundred and twenty pupils made up of forty eight pupils with formal kindergarten education and seventy two pupils without formal kindergarten education selected from ten public primary five classes. The sample consisted of boys and girls.The instrument used for data collection was English language achievement tests. The instruments were administered to students in their various schools. The scores obtained from the tests were analysed using the t-test to find the significant difference between the means of the two groups. The results of this study revealed that formal kindergarten education has a long term effect on the performance of primary school pupils since those with formal kindergarten education performed significantly better than those without. Another finding was that the sex of the students has no effect on the academic performance of pupils in primary school.Conclusively, it was confirmed in the study that pupils with formal kindergarten education perform better than those without in Nigerian context at least in primary school, hence this study emphasized the importance of formal kindergarten education.

  4. Z'-gauge Bosons as Harbingers of Low Mass Strings

    CERN Document Server

    Anchordoqui, Luis A; Goldberg, Haim; Huang, Xing; Lüst, Dieter; Taylor, Tomasz R

    2012-01-01

    Massive Z'-gauge bosons act as excellent harbingers for string compactifications with a low string scale. In D-brane models they are associated to U(1) gauge symmetries that are either anomalous in four dimensions or exhibit a hidden higher dimensional anomaly. We discuss the possible signals of massive Z'-gauge bosons at hadron collider machines (Tevatron, LHC) in a minimal D-brane model consisting out of four stacks of D-branes. In this construction, there are two massive gauge bosons, which can be naturally associated with baryon number B and B-L (L being lepton number). Here baryon number is always anomalous in four dimensions, whereas the presence of a four-dimensional B-L anomaly depends on the U(1)-charges of the right handed neutrinos. In case B-L is anomaly free, a mass hierarchy between the two associated Z'-gauge bosons can be explained. In our phenomenological discussion about the possible discovery of massive Z'-gauge bosons, we take as a benchmark scenario the dijet plus W signal, recently obser...

  5. Differences in Academic Achievement among Texas High School Students as a Function of Music Enrollment

    Science.gov (United States)

    Horton, Robert Wayne

    2012-01-01

    Purpose: The purpose of this study was to examine the score differences on the Texas Academic Knowledge and Skills (TAKS) Reading and Mathematics measures among students in Grades 10 and 11 as a function of music enrollment. Specifically, gender, ethnicity, socioeconomic status, and enrollment in choir, band, or orchestra or no music enrollment…

  6. Educational Goals and Motives as Possible Mediators in the Relationship between Social Support and Academic Achievement

    Science.gov (United States)

    Hernandez, Lucie; Oubrayrie-Roussel, Nathalie; Prêteur, Yves

    2016-01-01

    Perceived social support has been widely recognized as having beneficial effects on a person's development, and adolescence is no exception. The objective of this article is to go beyond this "stereotypical" vision of friendship by showing that social support does not always have a positive and direct effect on adolescents' academic…

  7. Entrepreneurship Education in Delta State Tertiary Institution as a Means of Achieving National Growth and Development

    Science.gov (United States)

    Osakwe, Regina N.

    2015-01-01

    This study examined entrepreneurship education in Delta Sate tertiary institutions as a means of national growth and development. Two research questions were asked to guide the study. The population comprised all the 1,898 academic staff in eight tertiary institutions in the state. A sample of 800 lecturers was drawn through the multi stage and…

  8. Feedback type as a moderator of the relationship between achievement goals and feedback reactions

    NARCIS (Netherlands)

    Anseel, Frederik; Van Yperen, Nico W.; Janssen, Onne; Duyck, Wouter

    2011-01-01

    The aim of the current study is to shed new light on the inconsistent relationship between performance-approach (PAp) goals and feedback reactions by examining feedback type as a moderator. Results of a field experiment (N = 939) using a web-based work simulation task showed that the effect of achie

  9. GaAsP solar cells on GaP/Si with low threading dislocation density

    Science.gov (United States)

    Yaung, Kevin Nay; Vaisman, Michelle; Lang, Jordan; Lee, Minjoo Larry

    2016-07-01

    GaAsP on Si tandem cells represent a promising path towards achieving high efficiency while leveraging the Si solar knowledge base and low-cost infrastructure. However, dislocation densities exceeding 108 cm-2 in GaAsP cells on Si have historically hampered the efficiency of such approaches. Here, we report the achievement of low threading dislocation density values of 4.0-4.6 × 106 cm-2 in GaAsP solar cells on GaP/Si, comparable with more established metamorphic solar cells on GaAs. Our GaAsP solar cells on GaP/Si exhibit high open-circuit voltage and quantum efficiency, allowing them to significantly surpass the power conversion efficiency of previous devices. The results in this work show a realistic path towards dual-junction GaAsP on Si cells with efficiencies exceeding 30%.

  10. Private Regional Universities as Alternatives to World Class Universities: Achievable Goals for Developing Nations

    Directory of Open Access Journals (Sweden)

    Keith J. Roberts

    2011-12-01

    Full Text Available A predominant discussion in Asian higher education is the identification and value of world class universities. The pressure to develop world class universities is coming from two sectors. First, the governments themselves see a world class university as a critical prerequisite to moving innovation into the economy and thereby moving the economy ahead and also as a source of status and prestige for the country. Second, parents who are keenly aware of the best universities in the world apply pressure to have equally prestigious universities in their native countries. Although world class universities move the frontiers of knowledge ahead, and clearly help their nation by providing a source of scientists and educated professionals via their graduate schools, many students, especially undergraduates, may be better served by regional universities with emphasis on pedagogy at the undergraduate level. The purpose of this article is to propose that regional private universities provide an alternative, not a replacement, to large research universities as a meaningful investment for both the regional economy and the student.

  11. Short-Term Memory as an Additional Predictor of School Achievement for Immigrant Children?

    Science.gov (United States)

    te Nijenhuis, Jan; Resing, Wilma; Tolboom, Elsbeth; Bleichrodt, Nico

    2004-01-01

    The predictive validity and utility of assessment procedures can be increased by adding predictors to the prediction supplied by general ability tests. Of Jensen's early work comes the suggestion of focusing on the cognitive ability short-term memory (STM), especially for low-"g" Black children. Meta-analysis convincingly shows high predictive…

  12. Apparent Retrocausation as a Consequence of Orthodox Quantum Mechanics Refined to Accommodate the Principle of Sufficient Reason

    CERN Document Server

    Stapp, Henry P

    2011-01-01

    The principle of sufficient reason asserts that anything that happens does so for a reason: no definite state of affairs can come into being unless there is a sufficient reason why that particular thing should happen. This principle is usually attributed to Leibniz, although the first recorded Western philosopher to use it was Anaximander of Miletus. The demand that nature be rational, in the sense that it be compatible with the principle of sufficient reason, conflicts with a basic feature of contemporary orthodox physical theory, namely the notion that nature's response to the probing action of an observer is determined by pure chance, and hence on the basis of absolutely no reason at all. This appeal to pure chance can be deemed to have no rational fundamental place in reason-based Western science. It is argued here, on the basis of the other basic principles of quantum physics, that in a world that conforms to the principle of sufficient reason, the usual quantum statistical rules will naturally emerge at...

  13. Retrocausal Effects as a Consequence of Orthodox Quantum Mechanics Refined to Accommodate The Principle of Sufficient Reason

    CERN Document Server

    Stapp, Henry P

    2011-01-01

    The principle of sufficient reason asserts that anything that happens does so for a reason: no definite state of affairs can come into being unless there is a sufficient reason why that particular thing should happen. This principle is usually attributed to Leibniz, although the first recorded Western philosopher to use it was Anaximander of Miletus. The demand that nature be rational, in the sense that it be compatible with the principle of sufficient reason, conflicts with a basic feature of contemporary orthodox physical theory, namely the notion that nature's response to the probing action of an observer is determined by pure chance, and hence on the basis of absolutely no reason at all. This appeal to pure chance can be deemed to have no rational fundamental place in reason-based Western science. It is argued here, on the basis of the other basic principles of quantum physics, that in a world that conforms to the principle of sufficient reason, the usual quantum statistical rules will naturally emerge at...

  14. Retrocausal Effects As A Consequence of Orthodox Quantum Mechanics Refined To Accommodate The Principle Of Sufficient Reason

    Science.gov (United States)

    Stapp, Henry P.

    2011-11-01

    The principle of sufficient reason asserts that anything that happens does so for a reason: no definite state of affairs can come into being unless there is a sufficient reason why that particular thing should happen. This principle is usually attributed to Leibniz, although the first recorded Western philosopher to use it was Anaximander of Miletus. The demand that nature be rational, in the sense that it be compatible with the principle of sufficient reason, conflicts with a basic feature of contemporary orthodox physical theory, namely the notion that nature's response to the probing action of an observer is determined by pure chance, and hence on the basis of absolutely no reason at all. This appeal to pure chance can be deemed to have no rational fundamental place in reason-based Western science. It is argued here, on the basis of the other basic principles of quantum physics, that in a world that conforms to the principle of sufficient reason, the usual quantum statistical rules will naturally emerge at the pragmatic level, in cases where the reason behind nature's choice of response is unknown, but that the usual statistics can become biased in an empirically manifest way when the reason for the choice is empirically identifiable. It is shown here that if the statistical laws of quantum mechanics were to be biased in this way then the basically forward-in-time unfolding of empirical reality described by orthodox quantum mechanics would generate the appearances of backward-time-effects of the kind that have been reported in the scientific literature.

  15. Low-E Storm Windows Gain Acceptance as a Home Weatherization Measure

    Energy Technology Data Exchange (ETDEWEB)

    Gilbride, Theresa L.; Cort, Katherine A.

    2016-05-16

    This article for Home Energy Magazine describes work by the U.S. Department of Energy to develop low-emissivity storm windows as an energy efficiency-retrofit option for existing homes. The article describes the low-emissivity invisible silver metal coatings on the glass, which reflect heat back into the home in winter or back outside in summer and the benefits of low-e storm windows including insulation, air sealing, noise blocking, protection of antique windows, etc. The article also describes Pacific Northwest National Laboratory's efforts on behalf of DOE to overcome market barriers to adoption of the technology, including performance validation studies in the PNNL Lab Homes, cost effectiveness analysis, production of reports, brochures, how-to guides on low-e storm window installation for the Building America Solution Center, and a video posted on YouTube. PNNL's efforts were reviewed by the Pacific Northwest Regional Technical Forum (RTF), which serves as the advisory board to the Pacific Northwest Electric Power Planning Council and Bonneville Power Administration. In late July 2015, the RTF approved the low-e storm window measure’s savings and specifications, a critical step in integrating low-e storm windows into energy-efficiency planning and utility weatherization and incentive programs. PNNL estimates that more than 90 million homes in the United States with single-pane or low-performing double-pane windows would benefit from the technology. Low-e storm windows are suitable not only for private residences but also for small commercial buildings, historic properties, and facilities that house residents, such as nursing homes, dormitories, and in-patient facilities. To further assist in the market transformation of low-e storm windows and other high-efficiency window attachments, DOE helped found the window Attachment Energy Rating Council (AERC) in 2015. AERC is an independent, public interest, non-profit organization whose mission is to rate

  16. Critical perspectives on cultural competence as a strategic opportunity for achieving high performance in healthcare organizations.

    Science.gov (United States)

    Strelitz, Philippa; Watson, Kerry

    2008-01-01

    * Cultural proficiency is a critical component of diversity competence. Diversity competency attends to issues of cultural proficiency and links cultural competence to issues of diverse representation and organizational inclusivity. * Developing and applying cultural competencies in diagnostic and invasive imaging services provides strategic opportunities to experience better patient cooperation, increase patient satisfaction, reduce medical errors, reduce patient complaints, and improve service recovery. * New Jersey recently passed legislation that requires 16 hours of cultural competency education as a condition of licensure to practice medicine. Four other states have similar legislation pending. The state of Washington passed legislation requiring all state accredited programs to include cultural competency education.

  17. Herbicides as weed control agents: state of the art: II. Recent achievements.

    Science.gov (United States)

    Kraehmer, Hansjoerg; van Almsick, Andreas; Beffa, Roland; Dietrich, Hansjoerg; Eckes, Peter; Hacker, Erwin; Hain, Ruediger; Strek, Harry John; Stuebler, Hermann; Willms, Lothar

    2014-11-01

    In response to changing market dynamics, the discovery of new herbicides has declined significantly over the past few decades and has only seen a modest upsurge in recent years. Nevertheless, the few introductions have proven to be interesting and have brought useful innovation to the market. In addition, herbicide-tolerant or herbicide-resistant crop technologies have allowed the use of existing nonselective herbicides to be extended into crops. An increasing and now major challenge is being posed by the inexorable increase in biotypes of weeds that are resistant to herbicides. This problem is now at a level that threatens future agricultural productivity and needs to be better understood. If herbicides are to remain sustainable, then it is a must that we adopt diversity in crop rotation and herbicide use as well as increase the use of nonchemical measures to control weeds. Nevertheless, despite the difficulties posed by resistant weeds and increased regulatory hurdles, new screening tools promise to provide an upsurge of potential herbicide leads. Our industry urgently needs to supply agriculture with new, effective resistance-breaking herbicides along with strategies to sustain their utility. PMID:25104721

  18. Herbicides as Weed Control Agents: State of the Art: II. Recent Achievements[C

    Science.gov (United States)

    Kraehmer, Hansjoerg; van Almsick, Andreas; Beffa, Roland; Dietrich, Hansjoerg; Eckes, Peter; Hacker, Erwin; Hain, Ruediger; Strek, Harry John; Stuebler, Hermann; Willms, Lothar

    2014-01-01

    In response to changing market dynamics, the discovery of new herbicides has declined significantly over the past few decades and has only seen a modest upsurge in recent years. Nevertheless, the few introductions have proven to be interesting and have brought useful innovation to the market. In addition, herbicide-tolerant or herbicide-resistant crop technologies have allowed the use of existing nonselective herbicides to be extended into crops. An increasing and now major challenge is being posed by the inexorable increase in biotypes of weeds that are resistant to herbicides. This problem is now at a level that threatens future agricultural productivity and needs to be better understood. If herbicides are to remain sustainable, then it is a must that we adopt diversity in crop rotation and herbicide use as well as increase the use of nonchemical measures to control weeds. Nevertheless, despite the difficulties posed by resistant weeds and increased regulatory hurdles, new screening tools promise to provide an upsurge of potential herbicide leads. Our industry urgently needs to supply agriculture with new, effective resistance-breaking herbicides along with strategies to sustain their utility. PMID:25104721

  19. Transdisciplinarity as an inference technique to achieve a better understanding in the health and environmental sciences.

    Science.gov (United States)

    Annerstedt, Matilda

    2010-06-01

    The problems of the world are not categorised into disciplines. They are far more complex, a reality that the tradition of transdisciplinary research has recognised. When faced with questions in public health and sustainability, the traditional scientific paradigm often seems inadequate, and, at least in medicine, transdisciplinary research has not yet been fully appreciated or acknowledged. This lack of recognition may be partly caused by a lack of cooperation between disciplines and between science and society. In this paper, I discuss some of the challenges that scientists and policymakers face in public health and environment within a methodological context. I present transdisciplinarity as a modern research tool that should be applied in research in health and the environment and argue that these topics can be approached beyond the inherent obstacle of incommensurability between disciplines. Thus, a small step might be taken in this immense research arena.

  20. Vocabulary Learning as the Predictor of Third-Grader EFL Learners’ Achievement: A Case for Translation

    Directory of Open Access Journals (Sweden)

    Ali Jahangard

    2010-09-01

    Full Text Available The purpose of the study was to formulate a model to predict the performance of Iranian high school third-graders on the End of the Course Achievement (ECA tests through their performance on the vocabulary tests, which were administered throughout the course. To meet this end, thirty two learners – aging seventeen to nineteen, all male – participated in the study which took nine months to complete. Their linguistic abilities were approximately at Intermediate-Mid level according to the ACTFL proficiency guidelines (1998. The sampling procedure was the intact group method. 333 lexical items were taught to the learners in the decontextualized paired-associate
    translation method. The classes were held two hours a week in a nine-month course of time. Six sets of vocabulary tests were administered and every learner’s average was calculated. The learners’ scores on the ECA tests and their average scores on the vocabulary tests were analyzed through the regression analysis procedure to derive a model that could reliably predict the learners’ ECA scores through their average performance on the vocabulary scores. The analysis yielded the following
    formula: (AVERAGE VOCABULARY × 0.713 + 2.871± [3.1].

  1. Coping with stress and cognitive interference in student teachers performance as important factors influencing their achievement

    Directory of Open Access Journals (Sweden)

    Cirila Peklaj

    2001-06-01

    Full Text Available The purpose of our study was to investigate the relations between student teachers' strategies for coping with stressful situations, cognitive interference factors and successfulness of presentation of student teachers' seminar work. There were 135 student teachers participating in the study. At the beginning of the semester they filled in the Way of Coping Questionnaire (Folkman & Lazarus, 1988. After their presentation of seminar theme they reported about the cognitive interference factors during the presentation (distractive factors and intrusive thoughts. Different aspects of their performance were also evaluated by the teacher according to the well-known criteria. The analysis of the results showed significant correlations between certain ways of coping, cognitive interference factors and success of performance. Further statistical analysis showed significant differences in experiencing distractive factors and intrusive thoughts during presentation between students with low, medium and high performance success. The importance of successful strategies for coping with verbal presentation and the implications for student teacher education are discussed.

  2. The desmoid tumour: Therapeutic results of surgical intervention as compared to those achieved with radiotherapy

    International Nuclear Information System (INIS)

    Discussion of the case reports of nine patients treated for desmoid tumours in the light of 62 such cases described in the relevant literature between 1975 and 1979. Among the patients analysed for the purposes of this study 9 had desmoid tumours treated at our clinic, while the other 60 cases were described in the relevant literature of the past 5 years. The methods used in this cohort were surgery for 37 patients, radiation for 20 patients, excision and post-surgical radiation for 5 patients and various other treatments for the remaining cases. Careful analysis and assessment of the results led to the conclusion that the vast majority of desmoids can be expected to show a satisfactory response to radiation, even though no clear therapeutic superiority could be established for either radical excision or radiation. If surgery is chosen, this should be carried out with the aim of removing all of the tumour. In circumstances precluding radical excision it appears wise to use post-surgical radiation. Follow-up examinations should be carried out in all patients so as to permit immediate diagnosis and treatment of any recurrent tumours. Each desmoid tumour is to be treated on an individual basis. In small tumours it is safer to remove not only the lesion itself but also some of the surrounding intact tissue, tumours at a more advanced stage should be subjected to radiation or both surgery and subsequent radiotherapy. (orig./MG)

  3. GPR as a Low Impact Paleontogical Survey Technique

    Science.gov (United States)

    Sturdevant, G. C.; Leverence, R.; Stewart, R.

    2013-12-01

    The Deweyville Formation, a Pleistocene fluvial sandstone, is a prolific source of megafaunal fossils from periods of low stand environmental conditions. GPR was employed in an environmentally sensitive area in close proximity to a salt dome in Northwest Harris County, Texas as a method of evaluating the probable paleo-depositional environment and to prospect for potential further site development of two distinct fossiliferous zones. The primary zone of interest is a lag gravel bounded sand responsible for producing a regionally unique fossil assemblage including South American megafauna (Lundelius et al, 2013). The secondary zone of interest contains undisturbed mammoth remains housed in coarse white sand emplaced on top of a clay drape which has been hypothesized to represent an oxbow lake formed by the meandering paleo-Brazos river. With an accurate map of the paleo-channel planning future activity can focus on maximizing fossil recovery and minimizing site impact. Pulse EKKO 250 MHz, 400MHz, and 1GHz system was employed in a prospect area proximal to the secondary site to calibrate and evaluate these systems for their resolution and penetration depth in the modern sediments. The data was processed using EKKO Mapper and EKKO View Deluxe software packages, 3d volumes were produced and sliced. Preliminary results from the 250 MHz demonstrate successful imaging of the sand-clay interface. After these surveys were run a small portion of the site was excavated to confirm the estimated velocities, the observed anomalies, and refine our modeling and interpretation, and improve grid design for further surveys. It was confirmed that the sand-clay interface was easily observable using GPR, however the grid spacing proved to be too wide, leading to artifacts in the 3d volume produced.

  4. Do Students Who Get Low Grades Only in Research Methods Need the Same Help as Students Who Get Low Grades in All Topics in Psychology?

    Science.gov (United States)

    Barry, John A.

    2012-01-01

    Some psychology students achieve high grades in all classes except for research methods (RM). Previous research has usually treated low levels of achievement in RM as a unitary phenomenon, without reference to the grades the student is achieving in other subjects. The present internet survey explored preferences for learning RM in 140 psychology…

  5. Navigating Schooled Numeracies: Explanations for Low Achievement, in Mathematics of UK Children from Low SES Background

    Science.gov (United States)

    Baker, Dave; Street, Brian; Tomlin, Alison

    2006-01-01

    The intention of the research reported here was to seek explanations for low achievement in school mathematics, as conventionally assessed, that derive from broad understandings of mathematics as social. Such a broad social perspective can provide explanations for low achievement, which could lead to different understandings and hence to different…

  6. The Reasons to Lack of Electronic Banking Achievement in Iran

    Directory of Open Access Journals (Sweden)

    Mohsen Rasoulian

    2011-09-01

    importance of Internet, frameworks andencouraging policies to impress beneficiaries to use electronic banking. The second part introduces the culturalelements as the most important ones and then it attracts our attention to financial elements (the cost of Internetand commissions as the second influencing factor the influence of technical elements is fading away due to theimprovements in banking system. Different parameters like management obstacles also play an important role inthe way of electronic banking. The safety obstacles are influenced by the cultural issues and their direct influenceis not certified. Ghareche and Abdolbaghi introduce Internet foundation and decrease in service expenses,managers and experts, that this study confirms Internet foundation and decrease in service expenses. Moghaliconfirm culture as effective parameter (indirectly. Amade and Jafarpour introduce culture-social, managementand reject financial and technical parameters, that this study only confirms culture-social parameters as effectiveparameter.Conclusion: The result of study does not certify the safety obstacles and cultural, financial, and technicalmanagement obstacles are influencing respectively.

  7. Exploring the Role of Metonymy in Mathematical Understanding and Reasoning: The Concept of Derivative as an Example

    Science.gov (United States)

    Zandieh, Michelle J.; Knapp, Jessica

    2006-01-01

    In this paper we examine the roles that metonymy may play in student reasoning. To organize this discussion we use the lens of a structured derivative framework. The derivative framework consists of three layers of process-object pairs, one each for ratio, limit, and function. Each of the layers can then be illustrated in any appropriate context,…

  8. Functional Fixedness and Functional Reduction as Common Sense Reasonings in Chemical Equilibrium and in Geometry and Polarity of Molecules.

    Science.gov (United States)

    Furio, C.; Calatayud, M. L.; Barcenas, S. L.; Padilla, O. M.

    2000-01-01

    Focuses on learning difficulties in procedural knowledge, and assesses the procedural difficulties of grade 12 and first- and third-year university students based on common sense reasoning in two areas of chemistry--chemical equilibrium and geometry, and polarity of molecules. (Contains 55 references.) (Author/YDS)

  9. Faith, reason and belief in the "Apology for Raymond Sebon": are we Christians as we are Perigordines or Germans?

    Directory of Open Access Journals (Sweden)

    Telma de Souza Birchal

    2006-01-01

    Full Text Available This paper analyzes Montaigne's concept of "faith", in comparison with the concepts of "reason" and "belief", in relation to the role assigned to authority by the author of the Essays. The paper discusses mainly the rather established claim that Montaigne's skepticism would reduce faith to the scope of customs and beliefs.

  10. Non-participants and reasons for non-participation in a pragmatic trial of energy healing as cancer rehabilitation

    DEFF Research Database (Denmark)

    Techau, Marzcia Elisa Camille; Lunde, Anita; Pedersen, Christina Gundgaard;

    2014-01-01

    -participation in a pragmatic trial of energy healing for rehabilitation for colorectal cancer. Methods: Three to seven days after postal recruitment, all eligible participants (n=783) were contacted by telephone. Reasons given for non-participation were recorded in 5 categories. Data were analyzed using Chi2. Results: More...

  11. Self-regulated processes as predictors of students' achievement in music theory in Slovenian elementary music schools

    Directory of Open Access Journals (Sweden)

    Barbara Smolej Fritz

    2010-01-01

    Full Text Available The aim of the present research was to examine the relation between processes of selfregulated learning and achievement in Music Theory (MT, a basic and obligatory subject in Slovenian music schools. A total of 457 fifth- and sixth- grade students (153 boys and 303 girls from 10 different elementary music schools in Slovenia participated in the study. Students completed a questionnaire about affective-motivational processes and a questionnaire about (metacognitive processes of selfregulated learning in MT, as well as achievement test. The final grades were collected at the end of the school year. The results showed that significant correlation exists between almost all affective-motivational and (metacognitive processes of self-regulated learning and achievement. Affective-motivational factors emerged as better predictors of students' achievement than (metacognitive factors. The most important individual predictors were anxiety and competence. It was also found that self-regulated processes explain a greater amount of variance for final grades than for the achievement test.

  12. Southeast Asian refugee children: self-esteem as a predictor of depression and scholastic achievement in the U.S.

    Science.gov (United States)

    Fox, Patricia G; Burns, Kenneth R; Popovich, Judith M; Belknap, Ruth Ann; Frank-Stromborg, Marilyn

    2004-01-01

    The eruption of conflicts and war in this century has led to new masses of refugees and displaced persons. Globally, host countries will continue to confront issues of how to ensure the successful adaptation of refugees who typically are women and children. The United States received three major waves of Southeast Asian (SEA) refugees during the past twenty-five years. One million SEA refugees arrived in the past decade; the majority were children and adolescents. Today, there is still a lack of understanding surrounding mental health issues and their relationship to children's violence experience. We know that SEA refugee children suffered violence during the war in Southeast Asia, their escape from homelands, in camps of asylum and in the U.S. Although researchers have examined the relationship of violence with depression and post-traumatic stress disorder in refugee children, the findings have been unclear and sometimes conflictual in their relationship to scholastic achievement. In the U.S., healthy self-esteem is recognized as an important component of mental health and academic success, while low self-esteem is associated with depression and academic failure. In general, self-esteem and measures of self-esteem have not been studied cross-culturally. The authors report the findings of a measure of self-esteem, depression and academic achievement in a convenience sample of 237 Southeast Asian refugee children aged 6 to 17 years of age in the U.S. Internationally, nurses who assess the mental health of refugee children and design interventions to assist in their adaptation, will want to have an understanding of mental health issues cross-culturally.

  13. Racial/Ethnic Socialization and Parental Involvement in Education as Predictors of Cognitive Ability and Achievement in African American Children

    Science.gov (United States)

    Banerjee, Meeta; Harrell, Zaje A. T.; Johnson, Deborah J.

    2011-01-01

    Racial/ethnic socialization has not been studied in the context of other parenting behaviors such as parental involvement in education and its relationship to children's cognitive outcomes. The present study tested the impact of racial/ethnic socialization and parental involvement in education on cognitive ability and achievement in a sample of…

  14. Middle School Characteristics That Predict Student Achievement, as Measured by the School-Wide California API Score

    Science.gov (United States)

    Paredes, Josie Abaroa

    2013-01-01

    The purpose of this study was to investigate, through quantitative research, effective middle school characteristics that predict student achievement, as measured by the school-wide California API score. Characteristics were determined using an instrument developed by the Office of Superintendent of Public Instruction (OSPI), which asked middle…

  15. Efficacy and Utility Beliefs of Mothers and Children as Predictors of Mathematics Achievement for American Indian Students

    Science.gov (United States)

    Orona, Cynthia C.

    2013-01-01

    American Indians have the largest high school dropout rates of all ethnic groups in the United States. Though drop outs technically occur in high school, they actually begin with lowered academic achievement during elementary school years. Looking to mothers as the primary caretakers, this study sought to explore the correlations between American…

  16. Students' Commitment, Engagement and Locus of Control as Predictor of Academic Achievement at Higher Education Level

    Science.gov (United States)

    Sarwar, Muhammad; Ashrafi, Ghulam Muhammad

    2014-01-01

    The purpose of this study was to analyze Students' Commitment, Engagement and Locus of Control as predictors of Academic Achievement at Higher Education Level. We used analytical model and conclusive research approach to conduct study and survey method for data collection. We selected 369 students using multistage sampling technique from…

  17. Social Integration as a Factor in Academic Achievements of Children: A Case Study of African Immigrants in Louisville, Kentucky

    Science.gov (United States)

    Odetunde, Florence Olayinka

    2013-01-01

    This study explored how social integration of African immigrants in the Louisville metropolitan area of Kentucky could be a factor in the academic achievements of their children. It involved critically investigating how the process of their adjustments as immigrants might have been shaped by various personal and environmental factors such as…

  18. Gracilaria lemaneiformis polysaccharide as integrin-targeting surface decorator of selenium nanoparticles to achieve enhanced anticancer efficacy.

    Science.gov (United States)

    Jiang, Wenting; Fu, Yuanting; Yang, Fang; Yang, Yufeng; Liu, Ting; Zheng, Wenjie; Zeng, Lilan; Chen, Tianfeng

    2014-08-27

    The poor permeability of glioma parenchyma represents a major limit for antiglioblastoma drug delivery. Gracilaria lemaneiformis polysaccharide (GLP), which has a high binding affinity to αvβ3 integrin overexpressed in glioma cells, was employed in the present study to functionalize selenium nanoparticles (SeNPs) to achieve antiglioblastoma efficacy. GLP-SeNPs showed satisfactory size distribution, high stability, and selectivity between cancer and normal cells. In U87 glioma cell membrane, which has a high integrin expression level, GLP-SeNPs exhibited significantly higher cellular uptake than unmodified SeNPs. As expected, U87 cells exhibited a greater uptake of GLP-SeNPs than C6 cells with low integrin expression level. Furthermore, the internalization of GLP-SeNPs was inhibited by cyclo-(Arg-Gly-Asp-Phe-Lys) peptides, suggesting that cellular uptake into U87 cells and C6 cells occurred via αvβ3 integrin-mediated endocytosis. For U87 cells, the cytotoxicity of SeNPs decorated by GLP was enhanced significantly because of the induction of various apoptosis signaling pathways. Internalized GLP-SeNPs triggered intracellular reactive oxygen species downregulation. Therefore, p53, MAPKs, and AKT pathways were activated to advance cell apoptosis. These findings suggest that surface decoration of nanomaterials with GLP could be an efficient strategy for design and preparation of glioblastoma targeting nanodrugs.

  19. Gracilaria lemaneiformis polysaccharide as integrin-targeting surface decorator of selenium nanoparticles to achieve enhanced anticancer efficacy.

    Science.gov (United States)

    Jiang, Wenting; Fu, Yuanting; Yang, Fang; Yang, Yufeng; Liu, Ting; Zheng, Wenjie; Zeng, Lilan; Chen, Tianfeng

    2014-08-27

    The poor permeability of glioma parenchyma represents a major limit for antiglioblastoma drug delivery. Gracilaria lemaneiformis polysaccharide (GLP), which has a high binding affinity to αvβ3 integrin overexpressed in glioma cells, was employed in the present study to functionalize selenium nanoparticles (SeNPs) to achieve antiglioblastoma efficacy. GLP-SeNPs showed satisfactory size distribution, high stability, and selectivity between cancer and normal cells. In U87 glioma cell membrane, which has a high integrin expression level, GLP-SeNPs exhibited significantly higher cellular uptake than unmodified SeNPs. As expected, U87 cells exhibited a greater uptake of GLP-SeNPs than C6 cells with low integrin expression level. Furthermore, the internalization of GLP-SeNPs was inhibited by cyclo-(Arg-Gly-Asp-Phe-Lys) peptides, suggesting that cellular uptake into U87 cells and C6 cells occurred via αvβ3 integrin-mediated endocytosis. For U87 cells, the cytotoxicity of SeNPs decorated by GLP was enhanced significantly because of the induction of various apoptosis signaling pathways. Internalized GLP-SeNPs triggered intracellular reactive oxygen species downregulation. Therefore, p53, MAPKs, and AKT pathways were activated to advance cell apoptosis. These findings suggest that surface decoration of nanomaterials with GLP could be an efficient strategy for design and preparation of glioblastoma targeting nanodrugs. PMID:25073123

  20. Low molecular weight block copolymers as plasticizers for polystyrene

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Karsten; Nielsen, Charlotte Juel; Hvilsted, Søren

    2005-01-01

    Polystyrene-b-alkyl, polystyrene-b-polybutadiene-b-polystyrene, and polystyrene-b-poly(propylene glycol)monotridecyl ether were synthesized using macro initiators and atom transfer radical polymerization or by esterifications of homopolymers. The aim was a maximum molecular weight of 4 kg....../mol and minimum polystyrene content of 50 w/w%, which by us is predicted as the limits for solubility of polystyrene-b-alkyl in polystyrene. DSC showed polystyrene was plasticized, as seen by a reduction in glass transition temperature, by block copolymers consisting of a polystyrene block with molecular weight...... of approximately 1 kg/mol and an alkyl block with a molecular weight of approximately of 0.3 kg/mol. The efficiency of the block copolymers as plasticizers increases with decreasing molecular weight and polystyrene content. In addition, polystyrene-b-alkyl is found to be an efficient plasticizer also...

  1. The duty to give reasons as a guarantee for a fair trial under the sight of the European Court of Human Rights

    Directory of Open Access Journals (Sweden)

    Marcella Alves Mascarenhas Nardelli

    2015-06-01

    Full Text Available This paper aims to define the outlines of the judicial duty to provide reasons for their decisions in its theoretical aspect - according to contemporary procedural knowledge -, as well as to establish its importance for the concretion of a fair trial. At the same time, the duty to give reasons will be analyzed in a practical perspective according to the case-law of the European Court of Human Rights, with a special emphasis in the case Taxquet v. Belgium and its impact on Jury Trials.

  2. Using Eight Key Questions as an Inquiry-Based Framework for Ethical Reasoning Issues in a General Education Earth Systems and Climate Change Course

    Science.gov (United States)

    Johnson, E. A.; Ball, T. C.

    2014-12-01

    An important objective in general education geoscience courses is to help students evaluate social and ethical issues based upon scientific knowledge. It can be difficult for instructors trained in the physical sciences to design effective ways of including ethical issues in large lecture courses where whole-class discussions are not practical. The Quality Enhancement Plan for James Madison University, "The Madison Collaborative: Ethical Reasoning in Action," (http://www.jmu.edu/mc/index.shtml) has identified eight key questions to be used as a framework for developing ethical reasoning exercises and evaluating student learning. These eight questions are represented by the acronym FOR CLEAR and are represented by the concepts of Fairness, Outcomes, Responsibilities, Character, Liberty, Empathy, Authority, and Rights. In this study, we use the eight key questions as an inquiry-based framework for addressing ethical issues in a 100-student general education Earth systems and climate change course. Ethical reasoning exercises are presented throughout the course and range from questions of personal behavior to issues regarding potential future generations and global natural resources. In the first few exercises, key questions are identified for the students and calibrated responses are provided as examples. By the end of the semester, students are expected to identify key questions themselves and justify their own ethical and scientific reasoning. Evaluation rubrics are customized to this scaffolding approach to the exercises. Student feedback and course data will be presented to encourage discussion of this and other approaches to explicitly incorporating ethical reasoning in general education geoscience courses.

  3. Clinical examination findings as prognostic factors in low back pain

    DEFF Research Database (Denmark)

    Hartvigsen, Lisbeth; Kongsted, Alice; Hestbaek, Lise

    2015-01-01

    . Study selection, data extraction and appraisal of study quality were performed independently by two reviewers. RESULTS: A total of 5,332 citations were retrieved and screened for eligibility, 342 articles were assessed as full text and 49 met the inclusion criteria. Due to clinical and statistical...

  4. Rice Husk Ash Sandcrete Block as Low Cost Building Material

    Directory of Open Access Journals (Sweden)

    S.P.Sangeetha,

    2016-06-01

    Full Text Available Concrete is a widely used construction material for various types of structures due to its structural stability and strength. The construction industry is today consuming more than 400 million tonnes of concrete every year .Most of the increase in cement demand will be met by the use of supplementary cementing materials, as each ton of Portland cement clinker production is associated with similar amount of CO2 emission, which is a major source of global warming. Partial replacement of ordinary Portland cement with mineral admixtures like fly ash, ground granulated blast furnace slag, silica fume, metakaolin, Rice husk Ash (RHA,etc with plasticizers eliminates these drawbacks. The use of rice husk modifies the physical qualities of fresh cement paste as well as microstructure of paste after hardening. By burning the rice husk under a uncontrolled temperature in the atmosphere, a highly reactive RHA was obtained and the ash was utilized as a supplementary cementing material. This paper presents the effects of using Rice Husk Ash (RHA as a partial cement replacement material in mortar mixes. This work is based on an experimental study of mortar made with replacement of Ordinary Portland Cement (OPC with 10%, 20% 30% & 40% RHA. The properties investigated were the compressive strength, setting time, consistency, workability and specific gravity. Finally, a cost analysis was also done to compare the efficiency of rice husk ash sandcrete blocks. From the test results it can be concluded that rice husk ash can be utilized in day today life of manufacturing building blocks which are more economical and more eco-friendly than the cement concrete blocks which are produced now-a-days.

  5. [English as a foreign language (EFL) homework diaries: evaluating gains and constraints for self-regulated learning and achievement].

    Science.gov (United States)

    Rosário, Pedro; Mourão, Rosa; Trigo, Luisa; Suárez, Natalia; Fernández, Estrella; Tuero-Herrero, Ellián

    2011-11-01

    Although homework completion is said to be rather important to achievement, nowadays there is a growing concern of educators about the increasing number of students who do not engage properly on doing the homework tasks and the subsequent impact on school failure rates. Focusing on English as a Foreign Language (EFL) and using a sample of 591 Portuguese fifth and sixth graders, the present study analyses the role played by a number of homework variables on students' achievement (proximal and distal), and their mediating role on the use of self-regulated learning strategies and perceived self-efficacy in the domain. Data confirm the indirect effect of homework on school achievement, by means of the referred cognitive and motivational variables (use of self-regulated learning strategies and self-efficacy). These findings are further discussed in order to highlight the significant role homework completion can play on fighting school failure. PMID:22047858

  6. [August Weismann's concept of germ plasma as the basic reason for the inadequacy of neo-Darwinism].

    Science.gov (United States)

    Grodnitskiĭ, D L

    2000-01-01

    Neo-Darwinism is a result of synthesis of Darwinian concept of natural selection with Weismannian concept of germ plasma. The concept of germ plasma is based on a hypothesis that phenotypic traits are completely determined by genes. Hence, neo-Darwinism describes evolution as a process of alternation of gene frequencies under the effect of natural selection. This is an inadequate approach to the study of evolution. In the course of evolution, genes change their functions, whereas phenotypic characters change their corresponding genes. As a result, every step of evolutionary transformation changes the structure of phenotype-to-genotype correspondence. Therefore, phenotypic evolution cannot be described in genetic terms, the same as to human languages cannot be translated one into another whenever the meaning of words is constantly changing. Consequently, Weismannian germ-plasma concept adequately describes the relation of characters to genes only during stasis, but is inapplicable to evolution.

  7. Examining Students' Proportional Reasoning Strategy Levels as Evidence of the Impact of an Integrated LEGO Robotics and Mathematics Learning Experience

    Science.gov (United States)

    Martínez Ortiz, Araceli

    2015-01-01

    The presented study used a problem-solving experience in engineering design with LEGO robotics materials as the real-world mathematics-learning context. The goals of the study were (a) to determine if a short but intensive extracurricular learning experience would lead to significant student learning of a particular academic topic and (b) to…

  8. The Problem of Free-Riding in Group Projects: Looking beyond Social Loafing as Reason for Non-Contribution

    Science.gov (United States)

    Hall, David; Buzwell, Simone

    2013-01-01

    The increase in popularity of group work in higher education has been accompanied by an increase in the frequency of reports of students not equally contributing to work within the groups. Referred to as "free-riders", the effect of this behaviour on other students can make group work an unpleasant experience for some. Of most frustration to…

  9. How Should Educational Neuroscience Conceptualise the Relation between Cognition and Brain Function? Mathematical Reasoning as a Network Process

    Science.gov (United States)

    Varma, Sashank; Schwartz, Daniel L.

    2008-01-01

    Background: There is increasing interest in applying neuroscience findings to topics in education. Purpose: This application requires a proper conceptualization of the relation between cognition and brain function. This paper considers two such conceptualizations. The area focus understands each cognitive competency as the product of one (and only…

  10. LINERs as Low-Luminosity Active Galactic Nuclei

    CERN Document Server

    Ho, L C

    1998-01-01

    Many nearby galaxies contain optical signatures of nuclear activity in the form of LINER nuclei. LINERs may be the weakest and most common manifestation of the quasar phenomenon. The physical origin of this class of objects, however, has been ambiguous. I draw upon a number of recent observations to argue that a significant fraction of LINERs are low-luminosity active galactic nuclei.

  11. Application of a single-board computer as a low cost pulse generator

    CERN Document Server

    Fedrizzi, Marcus

    2015-01-01

    A BeagleBone Black (BBB) single-board open-source computer was implemented as a low-cost fully programmable pulse generator. The pulse generator makes use of the BBB Programmable Real-Time Unit (PRU) subsystem to achieve a deterministic temporal resolution of 5 ns, an RMS jitter of 290 ps and a timebase stability on the order of 10 ppm. A python based software framework has also been developed to simplify the usage of the pulse generator.

  12. Application of a single-board computer as a low-cost pulse generator

    International Nuclear Information System (INIS)

    A BeagleBone Black (BBB) single-board open-source computer was implemented as a low-cost fully programmable pulse generator. The pulse generator makes use of the BBB Programmable Real-Time Unit (PRU) subsystem to achieve a deterministic temporal resolution of 5 ns, an RMS jitter of 290 ps and a timebase stability on the order of 10 ppm. A Python-based software framework has also been developed to simplify the usage of the pulse generator. (paper)

  13. Large area, low capacitance, GaAs nanowire photodetector with a transparent Schottky collecting junction

    Energy Technology Data Exchange (ETDEWEB)

    Seyedi, M. A., E-mail: seyedi@usc.edu; Yao, M.; O' Brien, J.; Dapkus, P. D. [Center for Energy Nanoscience, University of Southern California, Los Angeles, California 90089 (United States); Wang, S. Y. [Center for Energy Nanoscience, University of Southern California, Los Angeles, California 90089 (United States); Nanostructured Energy Conversion Technology and Research (NECTAR), Advanced Studies Laboratories, University of California, Santa Cruz, California 95064, USA and NASA Ames Research Center, Moffett Field, California 94035 (United States)

    2013-12-16

    We present experimental results on a GaAs/Indium-Tin-Oxide Schottky-like heterojunction photodetector based on a nanowire device geometry. By distributing the active detecting area over an array of nanowires, it is possible to achieve large area detection with low capacitance. Devices with bare GaAs and passivated AlGaAs/GaAs nanowires are fabricated to compare the responsivity with and without surface passivation. We are able to achieve responsivity of >0.5A/W and Signal-Noise-Ratio in excess of 7 dB for 2 V applied reverse bias with passivated nanowire devices. Capacitance-voltage measurement yields <5 nF/cm{sup 2}, which shows a strong possibility for high-speed applications with a broad area device.

  14. Reasoning Abilities in Primary School: A Pilot Study on Poor Achievers vs. Normal Achievers in Computer Game Tasks

    Science.gov (United States)

    Dagnino, Francesca Maria; Ballauri, Margherita; Benigno, Vincenza; Caponetto, Ilaria; Pesenti, Elia

    2013-01-01

    This paper presents the results of preliminary research on the assessment of reasoning abilities in primary school poor achievers vs. normal achievers using computer game tasks. Subjects were evaluated by means of cognitive assessment on logical abilities and academic skills. The aim of this study is to better understand the relationship between…

  15. Strain-Engineered Low-Density InAs Bilayer Quantum Dots for Single Photon Emission

    Institute of Scientific and Technical Information of China (English)

    LI Zhan-Guo; LIU Guo-Jun; LI Lin; FENG Ming; LI Mei; LU Peng; ZOU Yong-Gang; LI Lian-He; GAO Xin

    2010-01-01

    @@ We investigate the growth of strain-engineered low-density InAs bilayer quantum dots(BQDs)on GaAs bymolecular beam epitaxy.Owing to increasing dot size and In composition of the upper QDs,low-density BQDs in a GaAs matrix with an emission wavelength up to 1.4 μm at room temperature are achieved.Such a wavelength is larger than that of conventional QDs in a GaAs matrix(generally of about 1.3 μm).The optical properties of the BQDs are sensitive to annealing temperature used after spacer layer growth.Significant decrease of integrated PL intensity is observed as the annealing temperature increases.At IO K,single photon emission from the BQDs with wavelength around 1.3μm is observed.

  16. Strain-Engineered Low-Density InAs Bilayer Quantum Dots for Single Photon Emission

    International Nuclear Information System (INIS)

    We investigate the growth of strain-engineered low-density InAs bilayer quantum dots (BQDs) on GaAs by molecular beam epitaxy. Owing to increasing dot size and In composition of the upper QDs, low-density BQDs in a GaAs matrix with an emission wavelength up to 1.4 μm at room temperature are achieved. Such a wavelength is larger than that of conventional QDs in a GaAs matrix (generally of about 1.3 μm). The optical properties of the BQDs are sensitive to annealing temperature used after spacer layer growth. Significant decrease of integrated PL intensity is observed as the annealing temperature increases. At 10K, single photon emission from the BQDs with wavelength around 1.3 μm is observed. (condensed matter: structure, mechanical and thermal properties)

  17. GaAs/AlGaAs quantum well infrared photodetector with low noise

    Institute of Scientific and Technical Information of China (English)

    DENG Jun; WANG Bin; HAN Jun; LI Jian-jun; SHEN Guang-di

    2005-01-01

    A novel kind of multi-quantum well infrared photodetector(QWIP) is presented.In the new structure device,a p-type contact layer has been grown on the top of the conventional structure of QWIP,then a small tunneling current is instead of the large compensatory current,which made the device low dark current and low noise characteristics.The measured result of dark current is consistent with the calculated result,and the noise of the new structure QWIP is decreased to one third of the conventional QWIP.

  18. Communication as a predictor of willingness to donate one's organs: an addition to the Theory of Reasoned Action.

    Science.gov (United States)

    Jeffres, Leo W; Carroll, Jeanine A; Rubenking, Bridget E; Amschlinger, Joe

    2008-12-01

    Fishbein and Ajzen's theory of reasoned action has been used by many researchers, particularly in regard to health communication, to predict behavioral intentions and behavior. According to that theory, one's intention is the best predictor that one will engage in a behavior, and attitudes and social norms predict behavioral intentions. Other researchers have added different variables to the postulates of attitudes and social norms that Fishbein and Ajzen maintain are the best predictors of behavioral intention. Here we draw on data from a 2006 telephone survey (N = 420) gauging the awareness of an organ donation campaign in Northeast Ohio to examine the impact of communication on people's intentions. The current study supports the hypothesis that those who communicate with others are more likely to express a greater willingness to become an organ donor, but it expands the range of communication contexts. With demographics and attitudes toward organ donation controlled for, this study shows that communication with others about organ donation increases the willingness of individuals to have favorable attitudes about being an organ donor.

  19. 29 CFR 1605.2 - Reasonable accommodation without undue hardship as required by section 701(j) of title VII of the...

    Science.gov (United States)

    2010-07-01

    ... BECAUSE OF RELIGION § 1605.2 Reasonable accommodation without undue hardship as required by section 701(j... address other obligations under title VII not to discriminate on grounds of religion, nor other provisions... intended to provide guidance for statutes which require accommodation on bases other than religion such...

  20. Low grade inflammation as measured by levels of YKL-40

    DEFF Research Database (Denmark)

    Rathcke, Camilla Noelle; Raymond, Ilan; Kistorp, Caroline;

    2010-01-01

    BACKGROUND: Low grade inflammation is of pathogenic importance in the development of cardiovascular disease (CVD) and type 2 diabetes. The inflammation marker YKL-40 correlates with insulin resistance and is highly expressed in atherosclerotic plaques. We aimed to investigate whether YKL-40 could...... factors and markers including lipids, high sensitive C-reactive protein (hsCRP), N-terminal fragment of pro-brain natriuretic peptide (NT-proBNP) and urinary albumin/creatinine-ratio (UACR). Median follow-up period was 5.0 (0.17-5.28) years. RESULTS: In subjects without diabetes and CVD at baseline...

  1. Achievement motivation, locus of control and individuality as predictors of participative management in the South African educational environment

    OpenAIRE

    C. A. le Roux; Schmidt, C.; J. M. Schepers

    1997-01-01

    The shift to participative management is considered to be both inevitable and necessary. No study has thus far been reported in the participation literature in terms of predictor variables for participative management. The aim of this study was to investigate whether certain orientations - and in particular, achievement motivation, locus of control and individual vs collective orientations - could be identified that would serve as predictors of an inclination towards participative management....

  2. Stable same-sex friendships with higher achieving partners promote mathematical reasoning in lower achieving primary school children.

    Science.gov (United States)

    DeLay, Dawn; Laursen, Brett; Kiuru, Noona; Poikkeus, Anna-Maija; Aunola, Kaisa; Nurmi, Jari-Erik

    2015-11-01

    This study was designed to investigate friend influence over mathematical reasoning in a sample of 374 children in 187 same-sex friend dyads (184 girls in 92 friendships; 190 boys in 95 friendships). Participants completed surveys that measured mathematical reasoning in the 3rd grade (approximately 9 years old) and 1 year later in the 4th grade (approximately 10 years old). Analyses designed for dyadic data (i.e., longitudinal actor-partner interdependence model) indicated that higher achieving friends influenced the mathematical reasoning of lower achieving friends, but not the reverse. Specifically, greater initial levels of mathematical reasoning among higher achieving partners in the 3rd grade predicted greater increases in mathematical reasoning from 3rd grade to 4th grade among lower achieving partners. These effects held after controlling for peer acceptance and rejection, task avoidance, interest in mathematics, maternal support for homework, parental education, length of the friendship, and friendship group norms on mathematical reasoning. PMID:26402901

  3. LEETECH facility as a flexible source of low energy electrons

    CERN Document Server

    Attie, D; Bezshyyko, O; Burmistrov, L; Chaus, A; Colas, P; Fedorchuk, O; Golinka-Bezshyyko, L; Kadenko, I; Krylov, V; Kubytskyi, V; Lopez, R; Monard, H; Rodin, V; Titov, M; Tomassini, D; Variola, A

    2016-01-01

    A new versatile facility LEETECH for detector R&D, tests and calibration is designed and constructed. It uses electrons produced by the photoinjector PHIL at LAL, Orsay and provides a powerful tool for wide range R&D studies of different detector concepts delivering "mono-chromatic" samples of low energy electrons with adjustable energy and intensity. Among other innovative instrumentation techniques, LEETECH will be used for testing various gaseous tracking detectors and studying new Micromegas/InGrid concept which has very promising characteristics of spatial resolution and can be a good candidate for particle tracking and identification. In this paper the importance and expected characteristics of such facility based on detailed simulation studies are addressed.

  4. Porous hydroxyapatite tablets as carriers for low-dosed drugs.

    Science.gov (United States)

    Cosijns, A; Vervaet, C; Luyten, J; Mullens, S; Siepmann, F; Van Hoorebeke, L; Masschaele, B; Cnudde, V; Remon, J P

    2007-09-01

    The present study evaluated an innovative technique for the manufacturing of low-dosed tablets. Tablets containing hydroxyapatite and a pore forming agent (50% (w/w) Avicel PH 200/20, 37.5% and 50% corn starch/37.5% sorbitol) were manufactured by direct compression followed by sintering. The influence of pore forming agent (type and concentration), sinter temperature and sinter time on tablet properties was investigated. Sintering (1250 degrees C) revealed tablets with an acceptable friability (manufactured using a modified gelcasting technique yielding tablets with a median pore size of 60 and 80 microm. Release from these tablets was drastically increased indicating that the permeability of the tablets was influenced by the pore size, shape and connectivity of the porous network. Changing and controlling these parameters made it possible to obtain drug delivery systems providing different drug delivery behaviour.

  5. HEAT PUMP USING SUBSOIL WATERS AS LOW TEMPERATURE HEAT SOURCE

    Directory of Open Access Journals (Sweden)

    Denysova Alla

    2015-08-01

    Full Text Available One of the basic directions of perfection of heat supply systems is the tendency of transition to the low-temperature heating systems based on application of heat pump installations. We consider heat supply system with heat pump installations using subsoil waters. Numerical simulation of thermal processes in the elements of a single-stage and double-stage heat pump systems has been worked out. Values of depths of wells and their quantity, necessary for effective operation of the offered installations, and values of capacity of electric water pumps for subsoil waters unit are calculated. Capacity of compressor electric drive and coefficient of performance of heat pump for the conditions of the city of Odessa are presented.

  6. Functionalised inherently conducting polymers as low biofouling materials.

    Science.gov (United States)

    Zhang, Binbin; Nagle, Alex R; Wallace, Gordon G; Hanks, Timothy W; Molino, Paul J

    2015-01-01

    Diatoms are a major component of microbial biofouling layers that develop on man-made surfaces placed in aquatic environments, resulting in significant economic and environmental impacts. This paper describes surface functionalisation of the inherently conducting polymers (ICPs) polypyrrole (PPy) and polyaniline (PANI) with poly(ethylene glycol) (PEG) and their efficacy as fouling resistant materials. Their ability to resist interactions with the model protein bovine serum albumin (BSA) was tested using a quartz crystal microbalance with dissipation monitoring (QCM-D). The capacity of the ICP-PEG materials to prevent settlement and colonisation of the fouling diatom Amphora coffeaeformis (Cleve) was also assayed. Variations were demonstrated in the dopants used during ICP polymerisation, along with the PEG molecular weight, and the ICP-PEG reaction conditions, all playing a role in guiding the eventual fouling resistant properties of the materials. Optimised ICP-PEG materials resulted in a significant reduction in BSA adsorption, and > 98% reduction in diatom adhesion.

  7. Heat pumps and under floor heating as a heating system for Finnish low-rise residential buildings

    OpenAIRE

    Chuduk, Svetlana

    2010-01-01

    In bachelor’s thesis the study of under floor heating system with ground source heat pump for the heat transfers fluid heating is considered. The case study is low-rise residential building in Finland with under floor heating as a single heating system. The calculations of main parameters of under floor heating system and length of ground heat exchanger are conducted. As a result the conclusion about reasonable of using the studying system for low-rise residential building in Finn...

  8. Reasoning about geological space: Coupling 3D GeoModels and topological queries as an aid to spatial data selection

    Science.gov (United States)

    Pouliot, Jacynthe; Bédard, Karine; Kirkwood, Donna; Lachance, Bernard

    2008-05-01

    Topological relationships between geological objects are of great interest for mining and petroleum exploration. Indeed, adjacency, inclusion and intersection are common relationships between geological objects such as faults, geological units, fractures, mineralized zones and reservoirs. However, in the context of 3D modeling, actual geometric data models used to store those objects are not designed to manage explicit topological relationships. For example, with Gocad© software, topological analyses are possible but they require a series of successive manipulations and are time consuming. This paper presents the development of a 3D topological query prototype, TQuery, compatible with Gocad© modeling platform. It allows the user to export Gocad© objects to a data storage model that regularizes the topological relationships between objects. The development of TQuery was oriented towards the use of volumetric objects that are composed of tetrahedrons. Exported data are then retrieved and used for 3D topological and spatial queries. One of the advantages of TQuery is that different types of objects can be queried at the same time without restricting the operations to voxel regions. TQuery allows the user to analyze data more quickly and efficiently and does not require a 3D modeling specialist to use it, which is particularly attractive in the context of a decision-making aid. The prototype was tested on a 3D GeoModel of a continental red-bed copper deposit in the Silurian Robitaille Formation (Transfiguration property, Québec, Canada).

  9. Identification of ultrafast relaxation processes as a major reason for inefficient exciton diffusion in perylene-based organic semiconductors.

    Science.gov (United States)

    Settels, Volker; Schubert, Alexander; Tafipolski, Maxim; Liu, Wenlan; Stehr, Vera; Topczak, Anna K; Pflaum, Jens; Deibel, Carsten; Fink, Reinhold F; Engel, Volker; Engels, Bernd

    2014-07-01

    The exciton diffusion length (LD) is a key parameter for the efficiency of organic optoelectronic devices. Its limitation to the nm length scale causes the need of complex bulk-heterojunction solar cells incorporating difficulties in long-term stability and reproducibility. A comprehensive model providing an atomistic understanding of processes that limit exciton trasport is therefore highly desirable and will be proposed here for perylene-based materials. Our model is based on simulations with a hybrid approach which combines high-level ab initio computations for the part of the system directly involved in the described processes with a force field to include environmental effects. The adequacy of the model is shown by detailed comparison with available experimental results. The model indicates that the short exciton diffusion lengths of α-perylene tetracarboxylicdianhydride (PTCDA) are due to ultrafast relaxation processes of the optical excitation via intermolecular motions leading to a state from which further exciton diffusion is hampered. As the efficiency of this mechanism depends strongly on molecular arrangement and environment, the model explains the strong dependence of LD on the morphology of the materials, for example, the differences between α-PTCDA and diindenoperylene. Our findings indicate how relaxation processes can be diminished in perylene-based materials. This model can be generalized to other organic compounds. PMID:24909402

  10. Selected Wood Properties of Prunus Africana (Hook Grown in Kenya as Possible Reasons for its High Natural Durability

    Directory of Open Access Journals (Sweden)

    Francis Mburu

    2013-03-01

    Full Text Available Studies were carried out on the influence of Prunus africana heartwood extractives on the growth of selected wood decay fungi. Also, wood chemical and mineral content, dimensional stability and anatomical features of P. africana were studied. Heartwood extractives were tested in 100 ppm and 500 ppm concentrations on white, brown rot, and blue stain fungi and growth inhibition was determined as a factor of time. Dimensional stability was determined by computing the swelling coefficient after the blocks were saturated with moisture. Klason lignin, Kürschner cellulose, extractive and ash contents were determined by standard procedures. Infrared analyses were performed using Perkin Elmer FTIR spectrometer. Microscopic examination was performed using an environmental scanning electron microscope. The results showed that the wood is dimensionally stable, and contains 12.7 % extractives, 37.6 % cellulose and 30.4 % lignin. Extractives deposited in vessels are highly soluble in dichloromethane and mainly composed of terpenes. Extractives were able to inhibit the growth of white rot fungi Coriolus versicolor, brown rot fungi Poria placenta and blue stain fungi Aureobasidium pullulans at different concentrations tested and could explain the high durability of Prunus africana wood species.

  11. QR-STEM: Energy and Environment as a Context for Improving QR and STEM Understandings of 6-12 Grade Teachers II. The Quantitative Reasoning

    Science.gov (United States)

    Mayes, R.; Lyford, M. E.; Myers, J. D.

    2009-12-01

    The Quantitative Reasoning in STEM (QR STEM) project is a state level Mathematics and Science Partnership Project (MSP) with a focus on the mathematics and statistics that underlies the understanding of complex global scientific issues. This session is a companion session to the QR STEM: The Science presentation. The focus of this session is the quantitative reasoning aspects of the project. As students move from understandings that range from local to global in perspective on issues of energy and environment, there is a significant increase in the need for mathematical and statistical conceptual understanding. These understandings must be accessible to the students within the scientific context, requiring the special understandings that are endemic within quantitative reasoning. The QR STEM project brings together interdisciplinary teams of higher education faculty and middle/high school teachers to explore complex problems in energy and environment. The disciplines include life sciences, physics, chemistry, earth science, statistics, and mathematics. These interdisciplinary teams develop open ended performance tasks to implement in the classroom, based on scientific concepts that underpin energy and environment. Quantitative reasoning is broken down into three components: Quantitative Literacy, Quantitative Interpretation, and Quantitative Modeling. Quantitative Literacy is composed of arithmetic concepts such as proportional reasoning, numeracy, and descriptive statistics. Quantitative Interpretation includes algebraic and geometric concepts that underlie the ability to interpret a model of natural phenomena which is provided for the student. This model may be a table, graph, or equation from which the student is to make predictions or identify trends, or from which they would use statistics to explore correlations or patterns in data. Quantitative modeling is the ability to develop the model from data, including the ability to test hypothesis using statistical

  12. Trait mindfulness, reasons for living and general symptom severity as predictors of suicide probability in males with substance abuse or dependence.

    Directory of Open Access Journals (Sweden)

    Parvaneh Mohammadkhani

    2015-03-01

    Full Text Available The aim of this study was to evaluate suicide probability in Iranian males with substance abuse or dependence disorder and to investigate the predictors of suicide probability based on trait mindfulness, reasons for living and severity of general psychiatric symptoms.Participants were 324 individuals with substance abuse or dependence in an outpatient setting and prison. Reasons for living questionnaire, Mindfulness Attention Awareness Scale and Suicide probability Scale were used as instruments. Sample was selected based on convenience sampling method. Data were analyzed using SPSS and AMOS.The life-time prevalence of suicide attempt in the outpatient setting was35% and it was 42% in the prison setting. Suicide probability in the prison setting was significantly higher than in the outpatient setting (p<0.001. The severity of general symptom strongly correlated with suicide probability. Trait mindfulness, not reasons for living beliefs, had a mediating effect in the relationship between the severity of general symptoms and suicide probability. Fear of social disapproval, survival and coping beliefs and child-related concerns significantly predicted suicide probability (p<0.001.It could be suggested that trait mindfulness was more effective in preventing suicide probability than beliefs about reasons for living in individuals with substance abuse or dependence disorders. The severity of general symptom should be regarded as an important risk factor of suicide probability.

  13. Self-harm reasons, goal achievement, and prediction of future self-harm intent.

    Science.gov (United States)

    Lewis, Stephen P; Santor, Darcy A

    2010-05-01

    Self-harm may have several reasons, and these reasons may have corresponding implied goals. The current study examined reasons for self-harm and whether the a priori goals intended by these reasons were achieved. Fifty-seven individuals with a history of self-harm were recruited online and volunteered their time to complete a series of online questionnaires assessing past self-harm frequency, self-harm reasons, whether the goal associated with these reasons was achieved, and future self-harm intent. Reasons to reduce tension and dissociation associated with more past self-harm, a higher intent to self-harm again, and it was reported that the goals associated with reasons were achieved (i.e., these internal states were extinguished). Achievement of these goals (i.e., reported reductions in tension and dissociation) mediated the relation between corresponding self-harm reasons and intent to self-harm in the future. Findings support the view that self-harm is a maladaptive coping strategy and the reinforcement component of the experiential avoidance model of self-harm. Results have clinical implications and heuristic value for future research, which are discussed.

  14. Studying the impact of the class tournament as an assessment method on student achievements in physics courses

    CERN Document Server

    Dziob, Daniel; Sokolowska, Dagmara

    2015-01-01

    Testing knowledge is an integral part of summative assessment at schools. It can be performed in many different ways. In this study we propose assessment of physics knowledge by using a tournament approach. Prior to a statistical analysis of the results obtained over a tournament organized in one of Polish high schools, all its specifics are discussed at length, including the types of questions assigned, as well as additional self- and peer-evaluation questionnaires, constituting an integral part of the tournament. The impact of the tournament upon student improvement is examined by confronting the results of a post-test with pre-tournament students' achievements reflected in scores earned in former, written tests. We also present some of students' feedback on the idea of tournament as a tool of assessment. Both the analysis of the tournament results and the students' opinions point to at least several benefits of our approach.

  15. Learning from agriculture: understanding low-dose antimicrobials as drivers of resistome expansion

    Directory of Open Access Journals (Sweden)

    Yaqi eYou

    2014-06-01

    Full Text Available Antimicrobial resistance is a growing public health challenge worldwide, with agricultural use of antimicrobials being one major contributor to the emergence and dissemination of antimicrobial resistance. Globally, most antimicrobials are used in industrial food animal production, a major context for microbiomes encountering low-doses or subtherapeutic-levels of antimicrobial agents from all mechanistic classes. This modern practice exerts broad eco-evolutionary effects on the gut microbiome of food animals, which is subsequently transferred to animal waste. This waste contains complex constituents that are challenging to treat, including antimicrobial resistance determinants and low-dose antimicrobials. Unconfined storage or land deposition of a large volume of animal waste causes its wide contact with the environment and drives the expansion of the environmental resistome through mobilome facilitated horizontal genet transfer. The expanded environmental resistome, which encompasses both natural constituents and anthropogenic inputs, can persist under multiple stressors from agriculture and may re-enter humans, thus posing a public health risk to humans. For these reasons, this review focuses on agricultural antimicrobial use as a laboratory for understanding low-dose antimicrobials as drivers of resistome expansion, briefly summarizes current knowledge on this topic, highlights the importance of research specifically on environmental microbial ecosystems considering antimicrobial resistance as environmental pollution, and calls attention to the needs for longitudinal studies at the systems level.

  16. Low Carbon Development: Challenges for China as a Rapidly Industrializing Developing Country

    Institute of Scientific and Technical Information of China (English)

    HongboChen; HuaiguoHu; JiahuaPan

    2005-01-01

    China is in a stage of rapid industrialization. Over the past two decades, the size of the Chinese economy has more than quadrupled and energy consumption has more than doubled. The drive for more industrialization over the next two decades is leading to similar dynamics on a much larger scale. The net increase in emissions of CO2 between 1990 and 2001 amounted to 823 million tons, accounting for 27percent of the world total. Energy supplies and security are key constraints to industrialization; therefore, mitigation of emissions can in fact contribute to the achievement of development goals. There is a need for China to pursue a path of low carbon development. However, low and zero carbon technologies can hardly meet the demands for the physical expansion of the economy. In order to cope with the challenges for low carbon development, factors such as responsibility, capability, and potentials have to be taken into account in an international climate regime.

  17. On the Influence of New Media and Methods to Achieve Reasonable Spread

    Institute of Scientific and Technical Information of China (English)

    胡海燕

    2016-01-01

    The emergence of new media not only accelerates the spread of information and brings convenience to people, but also subtly changes every aspect of people's life.This paper aims to discuss the influences that the new media bring for people and the methods that can achieve reasonable spread. All of us have the responsibility and obligation to achieve reasonable spread and make the new media serve better for the human progress.

  18. Achieving high performance in intermediate temperature direct carbon fuel cells with renewable carbon as a fuel source

    International Nuclear Information System (INIS)

    Highlights: • Bamboo fiber and waste paper were pyrolyzed to generate bamboo carbon and waste paper carbon as anode fuels of IT-DCFC. • Superior cell performance was achieved with the waste paper carbon. • The results suggested the high performance was due to the highest thermal reactivity and the catalytic inherent impurities. • Calcite and kaolinite as inherent impurities favored the thermal decomposition and the electrooxidation of carbon. - Abstract: Three kinds of carbon sources obtained from carbon black, bamboo fiber and waste paper were investigated as anode fuels in an intermediate temperature direct carbon fuel cell. The carbon sources were characterized with X-ray photoelectron spectroscopy, thermal gravimetric analysis, etc. The results indicated that the waste paper carbon was more abundant in calcite and kaolinite, and showed higher thermal reactivity in the intermediate temperature range compared with the other two carbon sources. The cell performance was tested at 650 °C in a hybrid single cell, using Sm0.20Ce0.80O2−x as the electrolyte. As a result, the cell fed with waste paper carbon showed the highest performance among the three carbon sources, with a peak power density of 225 mW cm−2. The results indicated that its inherent impurities, such as calcite and kaolinite, might favor the thermal gasification of renewable carbon sources, which resulted in the enhanced performance of the intermediate temperature direct carbon fuel cell

  19. Angle-dependent XPS study of the mechanisms of 'high-low temperature' activation of GaAs photocathode

    International Nuclear Information System (INIS)

    The surface chemical compositions, atomic concentration percentage and layer thickness after 'high-temperature' single-step activation and 'high-low temperature' two-step activation were obtained using quantitative analysis of angle-dependent X-ray photoelectron spectroscopy (XPS). It was found that compared to single-step activation, the thickness of GaAs-O interface barrier had a remarkable decrease, the degree of As-O bond became much smaller and the Ga-O bond became dominating, and at the same time the thickness of (Cs, O) layer also had a deduction while the ratio of Cs to O had no change after two-step activation. The measured spectral response curves showed that a increase of 29% of sensitivity had been obtained after two-step activation. To explore the inherent mechanisms of influences of the evolution of GaAs(Cs, O) surface layers on photoemission, surface electric barrier models based on the experimental results were built. By calculation of electron escape probability it was found that the decrease of thickness of GaAs-O interface barrier and (Cs, O) layer is the main reasons, which explained why higher sensitivity is achieved after two-step activation than single-step activation

  20. Inverted pendulum as low-frequency pre-isolation for advanced gravitational wave detectors

    International Nuclear Information System (INIS)

    We have developed advanced seismic attenuation systems for Gravitational Wave (GW) detectors. The design consists of an Inverted Pendulum (IP) holding stages of Geometrical Anti-Spring Filters (GASF) and pendula, which isolate the test mass suspension from ground noise. The ultra-low-frequency IP suppresses the horizontal seismic noise, while the GASF suppresses the vertical ground vibrations. The three legs of the IP are supported by cylindrical maraging steel flexural joints. The IP can be tuned to very low frequencies by carefully adjusting its load. As a best result, we have achieved an ultra low, ∼12 mHz pendulum frequency for the system prototype made for Advanced LIGO (Laser Interferometer Gravitational Wave Observatory). The measured quality factor, Q, of this IP, ranging from Q∼2500 (at 0.45 Hz) to Q∼2 (at 12 mHz), is compatible with structural damping, and is proportional to the square of the pendulum frequency. Tunable counterweights allow for precise center-of-percussion tuning to achieve the required attenuation up to the first leg internal resonance (∼60 Hz for advanced LIGO prototype). All measurements are in good agreement with our analytical models. We therefore expect good attenuation in the low-frequency region, from ∼0.1to ∼50 Hz, covering the micro-seismic peak. The extremely soft IP requires minimal control force, which simplifies any needed actuation

  1. Novel Euler-LaCoste linkage as a very low frequency vertical vibration isolator.

    Science.gov (United States)

    Hosain, M A; Sirr, A; Ju, L; Blair, D G

    2012-08-01

    LaCoste linkage vibration isolators have shown excellent performance for ultra-low frequency vertical vibration isolation. However, such isolators depend on the use of conventional pre-stressed coil springs, which suffer from creep. Here, we show that compressional Euler springs can be configured to create a stable tension unit for use in a LaCoste structure. In a proof of concept experiment, we demonstrate a vertical resonance frequency of 0.15 Hz in an Euler-LaCoste configuration with 200 mm height. The system enables the use of very low creep maraging steel as spring elements to eliminate the creep while minimising spring mass and reducing the effect of parasitic resonances. Larger scale systems with optimized Euler spring boundary conditions should achieve performance suitable for applications on third generation gravitational wave detectors such as the proposed Einstein telescope.

  2. Achievement Goal Orientations and Self Handicapping as Mediator and Moderator of the Relationship between Intrinsic Achievement Motivation and Negative Automatic Thoughts in Adolescence Students

    Science.gov (United States)

    Kapikiran, Sahin

    2012-01-01

    The main purpose of this study was to examine the mediator and moderator role of self-handicapping and achievement goal orientations variables on the relationship between negative automatic thoughts intrinsic achievement motivation in high school students. 586 high school students, ranging in age from 14 to 20 (M = 16.08), adolescence students…

  3. Executive functioning and reading achievement in school: a study of Brazilian children assessed by their teachers as "poor readers".

    Science.gov (United States)

    Engel de Abreu, Pascale M J; Abreu, Neander; Nikaedo, Carolina C; Puglisi, Marina L; Tourinho, Carlos J; Miranda, Mônica C; Befi-Lopes, Debora M; Bueno, Orlando F A; Martin, Romain

    2014-01-01

    This study examined executive functioning and reading achievement in 106 6- to 8-year-old Brazilian children from a range of social backgrounds of whom approximately half lived below the poverty line. A particular focus was to explore the executive function profile of children whose classroom reading performance was judged below standard by their teachers and who were matched to controls on chronological age, sex, school type (private or public), domicile (Salvador/BA or São Paulo/SP) and socioeconomic status. Children completed a battery of 12 executive function tasks that were conceptual tapping cognitive flexibility, working memory, inhibition and selective attention. Each executive function domain was assessed by several tasks. Principal component analysis extracted four factors that were labeled "Working Memory/Cognitive Flexibility," "Interference Suppression," "Selective Attention," and "Response Inhibition." Individual differences in executive functioning components made differential contributions to early reading achievement. The Working Memory/Cognitive Flexibility factor emerged as the best predictor of reading. Group comparisons on computed factor scores showed that struggling readers displayed limitations in Working Memory/Cognitive Flexibility, but not in other executive function components, compared to more skilled readers. These results validate the account that working memory capacity provides a crucial building block for the development of early literacy skills and extends it to a population of early readers of Portuguese from Brazil. The study suggests that deficits in working memory/cognitive flexibility might represent one contributing factor to reading difficulties in early readers. This might have important implications for how educators might intervene with children at risk of academic under achievement. PMID:24959155

  4. Targeting PCSK9 as a promising new mechanism for lowering low-density lipoprotein cholesterol.

    Science.gov (United States)

    Della Badia, Laura A; Elshourbagy, Nabil A; Mousa, Shaker A

    2016-08-01

    Statins and other lipid-lowering drugs have dominated the market for many years for achievement of recommended levels of low-density lipoprotein cholesterol (LDL-C). However, a substantial number of high-risk patients are unable to achieve the LDL-C goal. Proprotein convertase subtilisin/kexin 9 (PCSK9) has recently emerged as a new, promising key therapeutic target for hypercholesterolemia. PCSK9 is a protease involved in chaperoning the low-density lipoprotein receptor to the process of degradation. PCSK9 inhibitors and statins effectively lower LDL-C. The PCSK9 inhibitors decrease the degradation of the LDL receptors, whereas statins mainly interfere with the synthetic machinery of cholesterol by inhibiting the key rate limiting enzyme, the HMG CoA reductase. PCSK9 inhibitors are currently being developed as monoclonal antibodies for their primary use in lowering LDL-C. They may be especially useful for patients with homozygous familial hypercholesterolemia, who at present receive minimal benefit from traditional statin therapy. The monoclonal antibody PCSK9 inhibitors, recently granted FDA approval, show the most promising safety and efficacy profile compared to other, newer LDL-C lowering therapies. This review will primarily focus on the safety and efficacy of monoclonal antibody PCSK9 inhibitors in comparison to statins. The review will also address new, alternative PCSK9 targeting drug classes such as small molecules, gene silencing agents, apolipoprotein B antisense oligonucleotides, and microsomal triglyceride transfer protein inhibitors. PMID:27133571

  5. Targeting PCSK9 as a promising new mechanism for lowering low-density lipoprotein cholesterol.

    Science.gov (United States)

    Della Badia, Laura A; Elshourbagy, Nabil A; Mousa, Shaker A

    2016-08-01

    Statins and other lipid-lowering drugs have dominated the market for many years for achievement of recommended levels of low-density lipoprotein cholesterol (LDL-C). However, a substantial number of high-risk patients are unable to achieve the LDL-C goal. Proprotein convertase subtilisin/kexin 9 (PCSK9) has recently emerged as a new, promising key therapeutic target for hypercholesterolemia. PCSK9 is a protease involved in chaperoning the low-density lipoprotein receptor to the process of degradation. PCSK9 inhibitors and statins effectively lower LDL-C. The PCSK9 inhibitors decrease the degradation of the LDL receptors, whereas statins mainly interfere with the synthetic machinery of cholesterol by inhibiting the key rate limiting enzyme, the HMG CoA reductase. PCSK9 inhibitors are currently being developed as monoclonal antibodies for their primary use in lowering LDL-C. They may be especially useful for patients with homozygous familial hypercholesterolemia, who at present receive minimal benefit from traditional statin therapy. The monoclonal antibody PCSK9 inhibitors, recently granted FDA approval, show the most promising safety and efficacy profile compared to other, newer LDL-C lowering therapies. This review will primarily focus on the safety and efficacy of monoclonal antibody PCSK9 inhibitors in comparison to statins. The review will also address new, alternative PCSK9 targeting drug classes such as small molecules, gene silencing agents, apolipoprotein B antisense oligonucleotides, and microsomal triglyceride transfer protein inhibitors.

  6. Low temperature preparation and superconductivity of F-doped SmFeAsO

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y.L.; Cui, Y.J. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C.H. [School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Yang, Y.; Wang, L.; Li, Y.C.; Zhang, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhao, Y., E-mail: yzhao@swjtu.edu.c [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia)

    2010-11-01

    A low temperature (1100 deg. C) process of preparing F-doped SmFeAsO samples has been developed using SmF{sub 3} with nanometer scale as the source of fluorine. A series of the SmFeAsO{sub 1-x}F{sub x} (x = 0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3) samples have been prepared using the present method. Compared with previous reports, the present SmF{sub 3} is more effective to introduce F into SmFeAsO system in which a transition temperature of 39 K can be observed when x = 0.05. The superconductivity is definitely enhanced with the increasing F-doping level. All the samples presented to be layered structure and the crystal particle size is about three times larger with sintering time increasing from 36 h to 48 h. Except for the nanometer scale of SmF{sub 3}, the flux effect of SmF{sub 3} is recognized to be another reason for the decrease of the sintering temperature. Further more, a relatively large amount of SmF{sub 3} was also employed in the raw materials to introduce excessive F and this has induced higher T{sub c} (55 K) in SmFeAsO{sub 0.8}F{sub 0.2+{delta}}system.

  7. Low-level radioactive-waste compacts. Status report as of July 1982

    International Nuclear Information System (INIS)

    The Low-Level Radioactive Waste Policy Act (P.L. 96-573), enacted in December 1980, established as federal policy that states take responsibility for providing disposal capacity for low-level radioactive waste (LLW) generated within their borders, except for defense waste and Federal R and D. At the request of Senator James A. McClure, Chairman of the Senate Committee on Energy and Natural Resources, DOE has documented the progress of states individually and collectively in fulfilling their responsibilities under the Public Law. Regionalization through formation of low-level waste compacts has been the primary vehicle by which many states are assuming this responsibility. To date seven low-level waste compacts have been drafted and six have been enacted by state legislatures or ratified by a governor. As indicated by national progress to date, DOE considers the task of compacting achievable by the January 1, 1986, exclusionary date set in law, although several states and NRC questioned this

  8. Low-level radioactive-waste compacts. Status report as of July 1982

    Energy Technology Data Exchange (ETDEWEB)

    1982-07-01

    The Low-Level Radioactive Waste Policy Act (P.L. 96-573), enacted in December 1980, established as federal policy that states take responsibility for providing disposal capacity for low-level radioactive waste (LLW) generated within their borders, except for defense waste and Federal R and D. At the request of Senator James A. McClure, Chairman of the Senate Committee on Energy and Natural Resources, DOE has documented the progress of states individually and collectively in fulfilling their responsibilities under the Public Law. Regionalization through formation of low-level waste compacts has been the primary vehicle by which many states are assuming this responsibility. To date seven low-level waste compacts have been drafted and six have been enacted by state legislatures or ratified by a governor. As indicated by national progress to date, DOE considers the task of compacting achievable by the January 1, 1986, exclusionary date set in law, although several states and NRC questioned this.

  9. Rudimentary, low tech incinerators as a means to produce reactive pozzolan out of sugar cane straw

    International Nuclear Information System (INIS)

    The ashes of agricultural wastes from the processing of sugar cane are recognized as having pozzolanic properties. Burning of these wastes under controlled conditions, e.g. temperature and residence time results in significant improvement in reactivity. There are many reports of low-tech incinerators that have been successfully used to produce reactive rice husk ash in Asia. The paper presents the results of the evaluation of a rudimentary incinerator where sugar cane straw is burnt in order to obtain a reactive ash. The incinerator is designed and constructed according to state-of-the-art recommendations for this kind of device. Various burning trials were performed in order to obtain ash for the experiment. X-ray diffraction analysis performed on powdered ash shows significant presence of amorphous (glassy) material. Lime-pozzolana pastes were prepared. The pastes were subjected to X-ray diffraction, thermo-gravimetric analysis, chemical titration, and SEM observation, as a means to examine the pozzolanicity of the ash via the progress with time of calcium hydroxide consumption, and changes in the pore size distribution and strength. Calcium silicate hydrate phases are the main reaction product of the pozzolanic reaction. The long residence time of the ash in the burning chamber seems to be the reason for the fairly low reactivity of the ash; the reactivity of the ash was not significantly improved in comparison with that of the ash burnt in uncontrolled conditions in the open air

  10. Executive Functioning and Reading Achievement in School: A study of Brazilian Children Assessed by Their Teachers as Poor Readers

    Directory of Open Access Journals (Sweden)

    Pascale M. J. Engel de Abreu

    2014-06-01

    Full Text Available This study examined executive functioning and reading achievement in 106 6- to 8-year-old Brazilian children from a range of social backgrounds of whom approximately half lived below the poverty line. A particular focus was to explore the executive function profile of children whose classroom reading performance was judged below standard by their teachers and who were carefully matched to controls on chronological age, sex, school type (Private or Public, domicile (Salvador/BA or São Paulo/SP, and socioeconomic status. Children completed a battery of 12 executive function tasks that were conceptually tapping cognitive flexibility, working memory, inhibition, and selective attention. Each executive function domain was assessed by several tasks. Principal component analysis extracted four factors that were labeled Working Memory/Cognitive Flexibility, Interference Suppression, Selective Attention, and Response Inhibition. Individual differences in executive functioning components made differential contributions to early reading achievement. The Working Memory/Cognitive Flexibility factor emerged as the best predictor of reading. Group comparisons on computed factor scores showed that the struggling readers presented limitations in Working Memory/Cognitive Flexibility, but not in other executive function components, compared to more skilled readers. These results validate the account that working memory capacity provides a crucial building block for the development of early literacy skills and extends it to a population of early readers of Portuguese from Brazil. The study suggests that deficits in working memory/cognitive flexibility might represent one contributing factor to reading difficulties in early readers which might have important implications for interventions for children at risk of school failure.

  11. Housing conditions as a social determinant of low birthweight and preterm low birthweight

    Directory of Open Access Journals (Sweden)

    Mario Vianna Vettore

    2010-12-01

    Full Text Available OBJECTIVE: To assess the relationship between housing conditions and low birthweight and preterm low birthweight among low-income women. METHODS: A case-control study was conducted with post-partum women living in the city of Rio de Janeiro, Southeast Brazil, in 2003-2005. Two groups of cases, low birthweight (n=96 and preterm low birthweight infants (n=68, were compared against normal weight term controls (n=393. Housing conditions were categorized into three levels: adequate, inadequate, and highly inadequate. Covariates included sociodemographic and anthropometric characteristics, risk behaviors, violence, anxiety, satisfaction during pregnancy, obstetric history and prenatal care. RESULTS: Poor housing conditions was independently associated with low birthweight (inadequate - OR 2.3 [1.1;4.6]; highly inadequate - OR 7.6 [2.1;27.6] and preterm low birthweight (inadequate - OR 2.2 [1.1;4.3]; highly inadequate - OR 7.6 [2.4;23.9] and factors associated with outcomes were inadequate prenatal care and previous preterm birth. Low income and low maternal body mass index remained associated with low birthweight. CONCLUSIONS: Poor housing conditions were associated with low birthweight and preterm low birthweight.

  12. A multifunctional DNA origami as carrier of metal complexes to achieve enhanced tumoral delivery and nullified systemic toxicity.

    Science.gov (United States)

    Huang, Yanyu; Huang, Wei; Chan, Leung; Zhou, Binwei; Chen, Tianfeng

    2016-10-01

    The use of metal complexes in cancer treatment is hampered by the insufficient accumulation in tumor regions and observable systemic toxicity due to their nonspecificity in vivo. Herein we present a cancer-targeted DNA origami as biocompatible nanocarrier of metal complexes to achieve advanced antitumor effect. The formation of unique tetrahedral nanostructure of DNA cages effectively enhances the interaction between ruthenium polypyridyl complexes (RuPOP) and the cages, thus increasing the drug loading efficacy. Conjugation of biotin to the DNA-based nanosystem (Bio-cage@Ru) enhances its specific cellular uptake, drug retention and cytotoxicity against HepG2 cells. Different from free RuPOP and the cage itself, Bio-cage@Ru translocates to cell nucleus after internalization, where it undergoes self-immolative cleavage in response to DNases, leading to triggered drug release and induction of ROS-mediated cell apoptosis. Moreover, in the nude mice model, the nanosystem specifically accumulates in tumor sites, thus exhibits satisfactory in vivo antitumor efficacy, and alleviates the damage of liver, kidney, lung and heart function of nude mice induced by RuPOP and tumor xenografts. Collectively, this study demonstrates a strategy for construction of biocompatible and cancer-targeted DNA origami with enhanced anticancer efficacy and reduced toxicity for next-generation cancer therapy. PMID:27388944

  13. A novel AlGaAs/GaAs heterojunction-based Hall sensor designed for low magnetic field measurements

    Science.gov (United States)

    Sghaier, H.; Bouzaïene, L.; Sfaxi, L.; Maaref, H.

    2004-05-01

    A self-consistent theoretical analysis, using both Schrödinger and Poisson equations, is made to investigate and propose novel Hall devices based on AlGaAs/GaAs heterostructures. The novel heterostructures are designed and optimized with respect to the measurements of low magnetic field du to their high sensitivity. In this study we attempt to show that the electron mobility of the studied heterostructure may be enhanced without loss in interface electron concentration by both increasing the spacer thickness and by inserting a -doping in a narrow quantum well within the AlGaAs barrier where the Al concentration in the well is less than in the barrier. Therefore, we predict a significant enhancement of device sensitivity to low magnetic field without compromise in noise performance.

  14. Achieving Low Carbon Social Housing Through Innovation

    OpenAIRE

    Jones, Keith; Desai, Apeksha; Kaluarachchi, Yamuna

    2012-01-01

    Achieving a low carbon future continues to be one of the most challenging issues facing today’s built environment professionals. While significant advances have been made in the area of new build, the same cannot be said for the existing housing stock. In the UK 70% of the housing that will exist in 2050 has already been built. If the UK is to have any chance of meeting its 2050 carbon reduction targets, effective refurbishment strategies that significantly reduce the carbon footprint of exis...

  15. 38 CFR 21.53 - Reasonable feasibility of achieving a vocational goal.

    Science.gov (United States)

    2010-07-01

    ... VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Vocational Rehabilitation and... employment handicap, or (2) A serious employment handicap. (Authority: 38 U.S.C. 3106(a)) (b) Definition. The... achievement of a vocational goal is not currently reasonably feasible, VA shall provide the...

  16. The Effect of Origami-Based Instruction on Spatial Visualization, Geometry Achievement, and Geometric Reasoning

    Science.gov (United States)

    Arici, Sevil; Aslan-Tutak, Fatma

    2015-01-01

    This research study examined the effect of origami-based geometry instruction on spatial visualization, geometry achievement, and geometric reasoning of tenth-grade students in Turkey. The sample ("n" = 184) was chosen from a tenth-grade population of a public high school in Turkey. It was a quasi-experimental pretest/posttest design. A…

  17. The relationship between vertical teaming in science and student achievement as reported in the Academic Excellence Indicator System (AEIS) at selected public schools in Bexar County, Texas

    Science.gov (United States)

    Arteaga, Veronica Hernandez

    The purpose of this study was to examine the relationship between vertical teaming in science and student achievement. This study compared student achievement of campuses implementing vertical teaming with schools that do not practice vertical teaming. In addition, this study explored the relationship between selected demographic variables and vertical teaming using Grade 5 Science TAKS results in the Academic Excellence Indicator System (AEIS). Campus demographic variables such as economically disadvantaged, minority students, English language learners, student mobility, and experienced teachers were researched. A call-out yielded 168 responses. With the exclusion of the 12 campuses, a total of 156 participating campuses from 18 traditional school districts remained. Campuses employing vertical teaming were self-identified on the basis of having implemented the process for two or more years. The gain in percent mastered for Science TAKS scores from 2004 to 2007 was used as the Science TAKS score variable. Results indicated that there was no significant difference in student achievement in science for campuses practicing vertical teaming and campuses that did not. The two-way ANOVA was used to measure the relationship between the independent variables (vertical teaming and campus demographic variables) on the dependent variable (student achievement on Science TAKS). The results suggested that campuses having low percentages of economically disadvantaged students statistically gained more on the Science TAKS than campuses that have high percentages of economically disadvantaged students irrespective of vertical teaming practices. In addition, campuses that have low percentages of minority students statistically gained more on the Science TAKS than campuses that have high percentages of minority students despite vertical teaming participation. Recommendations include districts, state, and federal agencies providing campuses with a high percent of economically

  18. The introduction of the personnel dosimetry information system in Greece designed as a relational database and the improvements achieved

    International Nuclear Information System (INIS)

    Dose record keeping is the making and keeping of personnel dose records for radiation workers. It is an essential part of the process of monitoring the exposure of individuals to radiation and shares in the same objectives. The dose record keeping is becoming more and more critical because of the importance of statistical analysis and epidemiological studies in radiation protection, and of the increasing cooperation and exchange of personnel between countries.The GAEC's personnel dosimetry laboratory assures the personnel dosimetry all over the country and keeps the official central dose record.The personnel dosimetry information system had been established in an electronic form on 1989 in Cobol language. Since then appeared various arguments that imposed the change of the data base used. Some of them are: 1. There was no distinction between establishments and their laboratories. 2. The workers did not have a unique code number. consequently, the total dose of a person working in more than one place could not't be estimated. The workers were directly related to their workplace, so if somebody changed his working place he was treated as a new entry, resulting an overestimation of the number of monitored workers introducing an source of errors in the collective and average dose calculations. 3. With the increasing applications of the ionising radiations many types of dosemeters became indispensable e.g. for beta and gamma, for neutrons and for the extremities. Also, the new category of outside workers appeared requesting a special treatment. All these distinctions were not achievable with the previous system. 4. Last years appeared an increasing, interesting in statistical analysis of the personal doses. A program written in Cobol does not't offer many possibilities and has no flexibility for such analysis. The new information system has been rebuilt under the design of a relational database with more possibilities and more flexibility. (authors)

  19. Microbial respiration and gene expression as a function of very low oxygen concentration

    DEFF Research Database (Denmark)

    Tiano, Laura

    on nitrite-oxidizing bacteria (NOB) and the expression of their terminal oxidases genes. The results from this project show that it is indeed possible, by combining high resolution sensor technology (the STOX sensor) and all-glass bottle incubation (Appendix A) to achieve an extreme high sensitivity in O2...... to pure cultures (Manuscript III), in order to assess the response of three species of NOB (Nitrospira defluvvi, N. moscoviensis and Nitrospina gracilis) to low O2 concentrations, and the oxygen regulation on the expression of the terminal oxidases genes in N.moscoviensis. The oxygen affinities...... recently, due to the lack of high-resolution methods for O2 concentration determination, several oxygen-related processes, such as aerobic respiration in pelagic aquatic ecosystems and in naturally oxygen poor waters (e.g. Oxygen Minimum Zones, OMZs), or the oxygen regulation of nitrification...

  20. Validation of the ultrastable low-noise current amplifier as travelling standard for small direct currents

    CERN Document Server

    Drung, Dietmar; Giblin, Stephen P; Djordjevic, Sophie; Piquemal, Francois; Séron, Olivier; Rengnez, Florentin; Götz, Martin; Pesel, Eckart; Scherer, Hansjörg

    2015-01-01

    An interlaboratory comparison of small-current generation and measurement capability is presented with the ultrastable low-noise current amplifier (ULCA) acting as travelling standard. Various measurements at direct currents between 0.16 nA and 13 nA were performed to verify the degree of agreement between the three national metrology institutes involved in the study. Consistency well within one part per million (ppm) was found. Due to harsh environmental conditions during shipment, the ULCA's transfer accuracy had been limited to about +/-0.4 ppm. Supplemental measurements performed at PTB indicate that further improvements in accuracy are possible. Relative uncertainties of 0.1 ppm are achieved by applying on-site calibration of the ULCA with a suitable cryogenic current comparator.

  1. Surfactant-free CZTS nanoparticles as building blocks for low-cost solar cell absorbers

    Science.gov (United States)

    Zaberca, O.; Oftinger, F.; Chane-Ching, J. Y.; Datas, L.; Lafond, A.; Puech, P.; Balocchi, A.; Lagarde, D.; Marie, X.

    2012-05-01

    A process route for the fabrication of solvent-redispersible, surfactant-free Cu2ZnSnS4 (CZTS) nanoparticles has been designed with the objective to have the benefit of a simple sulfide source which advantageously acts as (i) a complexing agent inhibiting crystallite growth, (ii) a surface additive providing redispersion in low ionic strength polar solvents and (iii) a transient ligand easily replaced by an carbon-free surface additive. This multifunctional use of the sulfide source has been achieved through a fine tuning of ((Cu2+)a(Zn2+)b(Sn4+)c(Tu)d(OH-)e)t+, Tu = thiourea) oligomers, leading after temperature polycondensation and S2- exchange to highly concentrated (c > 100 g l-1), stable, ethanolic CZTS dispersions. The good electronic properties and low-defect concentration of the sintered, crack-free CZTSe films resulting from these building blocks was shown by photoluminescence investigation, making these building blocks interesting for low-cost, high-performance CZTSe solar cells.

  2. Surfactant-free CZTS nanoparticles as building blocks for low-cost solar cell absorbers.

    Science.gov (United States)

    Zaberca, O; Oftinger, F; Chane-Ching, J Y; Datas, L; Lafond, A; Puech, P; Balocchi, A; Lagarde, D; Marie, X

    2012-05-11

    A process route for the fabrication of solvent-redispersible, surfactant-free Cu₂ZnSnS₄ (CZTS) nanoparticles has been designed with the objective to have the benefit of a simple sulfide source which advantageously acts as (i) a complexing agent inhibiting crystallite growth, (ii) a surface additive providing redispersion in low ionic strength polar solvents and (iii) a transient ligand easily replaced by an carbon-free surface additive. This multifunctional use of the sulfide source has been achieved through a fine tuning of ((Cu²⁺)(a)(Zn²⁺)(b)(Sn⁴⁺)(c)(Tu)(d)(OH⁻)(e))(t⁺), Tu = thiourea) oligomers, leading after temperature polycondensation and S²⁻ exchange to highly concentrated (c > 100 g l⁻¹), stable, ethanolic CZTS dispersions. The good electronic properties and low-defect concentration of the sintered, crack-free CZTSe films resulting from these building blocks was shown by photoluminescence investigation, making these building blocks interesting for low-cost, high-performance CZTSe solar cells. PMID:22513652

  3. Highly transparent, low-haze, hybrid cellulose nanopaper as electrodes for flexible electronics.

    Science.gov (United States)

    Xu, Xuezhu; Zhou, Jian; Jiang, Long; Lubineau, Gilles; Ng, Tienkhee; Ooi, Boon S; Liao, Hsien-Yu; Shen, Chao; Chen, Long; Zhu, J Y

    2016-06-16

    Paper is an excellent candidate to replace plastics as a substrate for flexible electronics due to its low cost, renewability and flexibility. Cellulose nanopaper (CNP), a new type of paper made of nanosized cellulose fibers, is a promising substrate material for transparent and flexible electrodes due to its potentially high transparency and high mechanical strength. Although CNP substrates can achieve high transparency, they are still characterized by high diffuse transmittance and small direct transmittance, resulting in high optical haze of the substrates. In this study, we proposed a simple methodology for large-scale production of high-transparency, low-haze CNP comprising both long cellulose nanofibrils (CNFs) and short cellulose nanocrystals (CNCs). By varying the CNC/CNF ratio in the hybrid CNP, we could tailor its total transmittance, direct transmittance and diffuse transmittance. By increasing the CNC content, the optical haze of the hybrid CNP could be decreased and its transparency could be increased. The direct transmittance and optical haze of the CNP were 75.1% and 10.0%, respectively, greatly improved from the values of previously reported CNP (31.1% and 62.0%, respectively). Transparent, flexible electrodes were fabricated by coating the hybrid CNP with silver nanowires (AgNWs). The electrodes showed a low sheet resistance (minimum 1.2 Ω sq(-1)) and a high total transmittance (maximum of 82.5%). The electrodes were used to make a light emitting diode (LED) assembly to demonstrate their potential use in flexible displays.

  4. Low-dark current 1024×1280 InGaAs PIN arrays

    Science.gov (United States)

    Yuan, Ping; Chang, James; Boisvert, Joseph C.; Karam, Nasser

    2014-06-01

    Photon counting imaging applications requires low noise from both detector and readout integrated circuit (ROIC) arrays. In order to retain the photon-counting-level sensitivity, a long integration time has to be employed and the dark current has to be minimized. It is well known that the PIN dark current is sensitive to temperature and a dark current density of 0.5 nA/cm2 was demonstrated at 7 °C previously. In order to restrain the size, weight, and power consumption (SWaP) of cameras for persistent large-area surveillance on small platforms, it is critical to develop large format PIN arrays with small pitch and low dark current density at higher operation temperatures. Recently Spectrolab has grown, fabricated and tested 1024x1280 InGaAs PIN arrays with 12.5 μm pitch and achieved 0.7 nA/cm2 dark current density at 15 °C. Based on our previous low-dark-current PIN designs, the improvements were focused on 1) the epitaxial material design and growth control; and 2) PIN device structure to minimize the perimeter leakage current and junction diffusion current. We will present characterization data and analyses that illustrate the contribution of various dark current mechanisms.

  5. The Effects of Different Approaches to Reading Instruction on Letter Detection Tasks in Normally Achieving and Low Achieving Readers

    Science.gov (United States)

    Faust, Miriam; Kandelshine-Waldman, Osnat

    2011-01-01

    The present study used two letter detection tasks, the classic missing letter effect paradigm and a single word versus familiar word compound version of this paradigm, to study bottom-up and top-down processes involved in reading in normally achieving as compared to low achieving elementary school readers. The research participants were children…

  6. Primary Reference Fuels (PRFs) as Surrogates for Low Sensitivity Gasoline Fuels

    KAUST Repository

    Bhavani Shankar, Vijai Shankar

    2016-04-05

    Primary Reference Fuels (PRFs) - binary mixtures of n-heptane and iso-octane based on Research Octane Number (RON) - are popular gasoline surrogates for modeling combustion in spark ignition engines. The use of these two component surrogates to represent real gasoline fuels for simulations of HCCI/PCCI engines needs further consideration, as the mode of combustion is very different in these engines (i.e. the combustion process is mainly controlled by the reactivity of the fuel). This study presents an experimental evaluation of PRF surrogates for four real gasoline fuels termed FACE (Fuels for Advanced Combustion Engines) A, C, I, and J in a motored CFR (Cooperative Fuels Research) engine. This approach enables the surrogate mixtures to be evaluated purely from a chemical kinetic perspective. The gasoline fuels considered in this study have very low sensitivities, S (RON-MON), and also exhibit two-stage ignition behavior. The first stage heat release, which is termed Low Temperature Heat Release (LTHR), controls the combustion phasing in this operating mode. As a result, the performance of the PRF surrogates was evaluated by its ability to mimic the low temperature chemical reactivity of the real gasoline fuels. This was achieved by comparing the LTHR from the engine pressure histories. The PRF surrogates were able to consistently reproduce the amount of LTHR, closely match the phasing of LTHR, and the compression ratio for the start of hot ignition of the real gasoline fuels. This suggests that the octane quality of a surrogate fuel is a good indicator of the fuel’s reactivity across low (LTC), negative temperature coefficient (NTC), and high temperature chemical (HTC) reactivity regimes.

  7. Growth and characterization of InAs quantum dots with low-density and long emission wavelength

    Institute of Scientific and Technical Information of China (English)

    Lin Li; Guojun Liu; Zhanguo Li; Mei Li; Xiaohua Wang

    2008-01-01

    The growth parameters affecting the deposition of self-assembled InAs quantum dots (QDs) on GaAs substrate by low-pressure metal-organic chemical vapor deposition (MOCVD) are reported. The low-density InAs QDs (~ 5 × 108 cm-2) are achieved using high growth temperature and low InAs coverage. Photolu-minescence (PL) measurements show the good optical quality of low-density QDs. At room temperature,the ground state peak wavelength of PL spectrum and full-width at half-maximum (FWHM) are 1361 nm and 23 meV (35 nm), respectively, which are obtained as the GaAs capping layer grown using triethylgallium (TEG) and tertiallybutylarsine (TBA). The PL spectra exhibit three emission peaks at 1361, 1280,and 1204 nm, which correspond to the ground state, the first excited state, and the second excited state of the QDs, respectively.

  8. Silicon solar cell characterization at low temperatures and low illumination as a function of particulate irradiation

    Science.gov (United States)

    Whitaker, A. F.; Little, S. A.; Peacock, C. L., Jr.

    1983-01-01

    Various configurations of back surface reflector silicon solar cells including small (2 x 2) cm and large (approx. 6 x 6) cm cells with conventional and wraparound contacts were subjected to 1 MeV electron irradiation and characterized under both Earth orbital and deep space conditions of temperatures and illuminations. Current-Voltage (I-V) data were generated from +65 C to -150 C and at incident illuminations from 135.3 mW/sq cm to 5.4 mW/sq cm for these cells. Degradation in cell performance which is manifested only under deep space conditions is emphasized. In addition, the effect of particle irradiation on the high temperature and high intensity and low temperature and low intensity performance of the cells is described. The cells with wraparound contacts were found to have lower efficiencies at Earth orbital conditions than the cells with conventional contacts.

  9. Highly monodisperse low-magnetization magnetite nanocubes as simultaneous T1-T2 MRI contrast agents

    Science.gov (United States)

    Sharma, V. K.; Alipour, A.; Soran-Erdem, Z.; Aykut, Z. G.; Demir, H. V.

    2015-06-01

    We report the first study of highly monodisperse and crystalline iron oxide nanocubes with sub-nm controlled size distribution (9.7 +/- 0.5 nm in size) that achieve simultaneous contrast enhancement in both T1- and T2-weighted magnetic resonance imaging (MRI). Here, we confirmed the magnetite structure of iron oxide nanocubes by X-ray diffraction (XRD), selected area electron diffraction (SAED) pattern, optical absorption and Fourier transformed infrared (FT-IR) spectra. These magnetite nanocubes exhibit superparamagnetic and paramagnetic behavior simultaneously by virtue of their finely controlled shape and size. The magnetic measurements reveal that the magnetic moment values are favorably much lower because of the small size and cubic shape of the nanoparticles, which results in an enhanced spin canting effect. As a proof-of-concept demonstration, we showed their potential as dual contrast agents for both T1- and T2-weighted MRI via phantom studies, in vivo imaging and relaxivity measurements. Therefore, these low-magnetization magnetite nanocubes, while being non-toxic and bio-compatible, hold great promise as excellent dual-mode T1 and T2 contrast agents for MRI.We report the first study of highly monodisperse and crystalline iron oxide nanocubes with sub-nm controlled size distribution (9.7 +/- 0.5 nm in size) that achieve simultaneous contrast enhancement in both T1- and T2-weighted magnetic resonance imaging (MRI). Here, we confirmed the magnetite structure of iron oxide nanocubes by X-ray diffraction (XRD), selected area electron diffraction (SAED) pattern, optical absorption and Fourier transformed infrared (FT-IR) spectra. These magnetite nanocubes exhibit superparamagnetic and paramagnetic behavior simultaneously by virtue of their finely controlled shape and size. The magnetic measurements reveal that the magnetic moment values are favorably much lower because of the small size and cubic shape of the nanoparticles, which results in an enhanced spin

  10. High performance InAs quantum dot lasers on silicon substrates by low temperature Pd-GaAs wafer bonding

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zihao; Preble, Stefan F. [Microsystems Engineering, Rochester Institute of Technology, Rochester, New York 14623 (United States); Yao, Ruizhe; Lee, Chi-Sen; Guo, Wei, E-mail: wei-guo@uml.edu [Physics and Applied Physics Department, University of Massachusetts Lowell, Lowell, Massachusetts 01854 (United States); Lester, Luke F. [Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States)

    2015-12-28

    InAs quantum dot (QD) laser heterostructures have been grown by molecular beam epitaxy system on GaAs substrates, and then transferred to silicon substrates by a low temperature (250 °C) Pd-mediated wafer bonding process. A low interfacial resistivity of only 0.2 Ω cm{sup 2} formed during the bonding process is characterized by the current-voltage measurements. The InAs QD lasers on Si exhibit comparable characteristics to state-of-the-art QD lasers on silicon substrates, where the threshold current density J{sub th} and differential quantum efficiency η{sub d} of 240 A/cm{sup 2} and 23.9%, respectively, at room temperature are obtained with laser bars of cavity length and waveguide ridge of 1.5 mm and 5 μm, respectively. The InAs QD lasers also show operation up to 100 °C with a threshold current density J{sub th} and differential quantum efficiency η{sub d} of 950 A/cm{sup 2} and 9.3%, respectively. The temperature coefficient T{sub 0} of 69 K from 60 to 100 °C is characterized from the temperature dependent J{sub th} measurements.

  11. The influence of a learning strategies programme on low achieving black secondary school students' academic achievement / Zelbia Sprang

    OpenAIRE

    Sprang, Zelbia

    2001-01-01

    The purpose of this study was to determine, by means of a review of literature and an empirical investigation, the influence of a learning strategies pro!:,rramme on low achieving Black Secondary School students' academic achievement. From the review ofliterature and the empirical study it was concluded that the effective use of learning strategies have an influence on academic achievement defined as Grade Point Average (GPA). It was also concluded that the effective use ofleam...

  12. EXAMINATION MANAGEMENT AS A WAY OF ACHIEVING QUALITY ASSURANCE IN ODL INSTITUTIONS: The Case of Zimbabwe Open University

    Directory of Open Access Journals (Sweden)

    Onias MAFA

    2013-01-01

    Full Text Available An examination is an important component of any institution that educates people. It is a form of assessment used to measure the students’ understanding of the concepts and principles they would have learnt. Zimbabwe Open University, an Open and Distance Learning institution has been setting its own examinations for the academic programmes offered. Through examinations, ZOU students are encouraged to take an active role in analysing and questioning the things they would have learnt. This paper discusses the examinations management at ZOU with a special focus on the setting, administering, marking right up to the publication of results. It will also discuss the challenges that ZOU is facing in conducting examinations. It will finally emerge with some valuable practical suggestions on how ZOU can improve on its examination management and thereby achieve quality assurance in all its programmes. The investigation adopted the qualitative methodology and a case study design to generate data to address the questions which guided the study. The purposively sampled sample was drawn from ZOU’s National Centre, Bulawayo and Matabeleland North Regions. The sample consisted of manager -examinations, manager- quality control, chairpersons of departments from different faculties, programme leaders, programme coordinators, regional quality coordinators, regional administrators, and students who were in their second year of study. Face-to-face interviews were used to generate data from manager -examinations, manager- quality control, regional quality coordinators and regional administrators. Data from chairpersons of departments from different faculties, programme leaders, programme coordinators, second year students were generated through focus group discussions. Major findings were the management of examinations at ZOU enhances quality assurance, cited activities which contributed to quality assurance included setting of examination items for the item

  13. EXAMINATION MANAGEMENT AS A WAY OF ACHIEVING QUALITY ASSURANCE IN ODL INSTITUTIONS: The Case of Zimbabwe Open University

    Directory of Open Access Journals (Sweden)

    Onias MAFA

    2012-04-01

    Full Text Available An examination is an important component of any institution that educates people. It is a form of assessment used to measure the students’ understanding of the concepts and principles they would have learnt. Zimbabwe Open University, an Open and Distance Learning institution has been setting its own examinations for the academic programmes offered. Through examinations, ZOU students are encouraged to take an active role in analysing and questioning the things they would have learnt. This paper discusses the examinations management at ZOU with a special focus on the setting, administering, marking right up to the publication of results. It will also discuss the challenges that ZOU is facing in conducting examinations. It will finally emerge with some valuable practical suggestions on how ZOU can improve on its examination management and thereby achieve quality assurance in all its programmes. The investigation adopted the qualitative methodology and a case study design to generate data to address the questions which guided the study. The purposively sampled sample was drawn from ZOU’s National Centre, Bulawayo and Matabeleland North Regions. The sample consisted of manager -examinations, manager- quality control, chairpersons of departments from different faculties, programme leaders, programme coordinators, regional quality coordinators, regional administrators, and students who were in their second year of study. Face-to-face interviews were used to generate data from manager -examinations, manager- quality control, regional quality coordinators and regional administrators. Data from chairpersons of departments from different faculties, programme leaders, programme coordinators, second year students were generated through focus group discussions. Major findings were the management of examinations at ZOU enhances quality assurance, cited activities which contributed to quality assurance included setting of examination items for the item

  14. Intrapersonal Achievement Goals and Underlying Reasons among Long Distance Runners: Their Relation with Race Experience, Self-Talk, and Running Time

    Directory of Open Access Journals (Sweden)

    Jochen Delrue

    2016-07-01

    Full Text Available In a sample of long distance runners, we examined the role of type of intrapersonal achievement goals (i.e., approach versus avoidance and type of underlying reasons (i.e., autonomous and controlled, assessed prior to the race, as predictors of both pre-race (e.g., race appraisals and post-race (e.g., flow experience outcomes. Of 221 (62.4% males runners, 111 reported pursuing an intrapersonal-approach goal (i.e., doing better than before as their dominant or preferred achievement goal for the race, while 86 prioritized intrapersonal-avoidance goals (i.e., avoiding to perform worse than before. Regression and path analyses showed that the type of achievement goals predicted none of the outcomes except for running time, with approach goals predicting better performance when compared to avoidance goals. Path analyses revealed that autonomous reasons underlying intrapersonal goal pursuit related positively to pre-race challenge appraisals, performance and, via need satisfaction, to flow experience. Interestingly, controlled reasons positively related to pre-race threat appraisals and positively predicted both positive and negative self-talk, with both yielding opposing relations with flow. These findings complement past research on the intersection between the Achievement Goal Approach and Self-Determination Theory and highlight the value of studying the reasons underlying intrapersonal achievement goals.

  15. COMPARATIVE PERSPECTIVES OF STUDY STRATEGIES AMONG HIGH AND LOW ACHIEVERS DISTANCE LEARNING STUDENTS

    Directory of Open Access Journals (Sweden)

    Muhammad Imran YOUSUF

    2009-07-01

    Full Text Available The main aim of this research is to better understand and draw perceptions of low and high achiever distance learners about their study patterns. The study indicates the areas where significant difference is found among low and high achievers of Allama Iqbal Open University, Pakistan through a self developed questionnaire covering their preferred study location, study times, number of hours spent on study, the difficulties affecting their study patterns and the organization of study strategies in comparative perspective. Greater difficulties were being faced by low achievers in their study. Increased difficulties were encountered by low achievers with study material, volume of study, self-motivation and other factors. There was no significant difference between low and high achievers for their study strategies of studying materials without taking notes and reading aloud. Greater low achievers attempted easy portions of their study material first and took notes simultaneously as compared to high achievers.

  16. The Snapping Elbow Syndrome as a Reason for Chronic Elbow Neuralgia in a Tennis Player – MR, US and Sonoelastography Evaluation

    Science.gov (United States)

    Łasecki, Mateusz; Olchowy, Cyprian; Pawluś, Aleksander; Zaleska-Dorobisz, Urszula

    2014-01-01

    Summary Background Ulnar neuropathy is the second most common peripheral nerve neuropathy after median neuropathy, with an incidence of 25 cases per 100 000 men and 19 cases per 100 000 women each year. Skipping (snapping) elbow syndrome is an uncommon cause of pain in the posterior-medial elbow area, sometimes complicated by injury of the ulnar nerve. One of the reason is the dislocation of the abnormal insertion of the medial triceps head over the medial epicondyle during flexion and extension movements. Others are: lack of the Osboune fascia leading to ulnar nerve instability and focal soft tissue tumors (fibromas, lipomas, etc). Recurrent subluxation of the nerve at the elbow results in a tractional and frictional neuritis with classical symptoms of peripheral neuralgia. As far as we know snapping triceps syndrome had never been evaluated in sonoelastography. Case Report A 28yo semi-professional left handed tennis player was complaining about pain in posterior-medial elbow area. Initial US examination suggest golfers elbow syndrome which occurs quite commonly and has a prevalence of 0.3–0.6% in males and 0–3–1.1% in women and may be associated (approx. 50% of cases) with ulnar neuropathy. However subsequently made MRI revealed unusual distal triceps anatomy, moderate ulnar nerve swelling and lack of medial epicondylitis symptoms. Followed (second) US examination and sonoelastography have detected slipping of the both ulnar nerve and the additional band of the medial triceps head. Discussion Snapping elbow syndrome is a poorly known medical condition, sometimes misdiagnosed as the medial epicondylitis. It describes a broad range of pathologies and anatomical abnormalities. One of the most often reasons is the slipping of the ulnar nerve as the result of the Osborne fascia/anconeus epitrochlearis muscle absence. Simultaneously presence of two or more “snapping reasons” is rare but should be always taken under consideration. Conclusions There are no

  17. The Snapping Elbow Syndrome as a Reason for Chronic Elbow Neuralgia in a Tennis Player – MR, US and Sonoelastography Evaluation

    International Nuclear Information System (INIS)

    Ulnar neuropathy is the second most common peripheral nerve neuropathy after median neuropathy, with an incidence of 25 cases per 100 000 men and 19 cases per 100 000 women each year. Skipping (snapping) elbow syndrome is an uncommon cause of pain in the posterior-medial elbow area, sometimes complicated by injury of the ulnar nerve. One of the reason is the dislocation of the abnormal insertion of the medial triceps head over the medial epicondyle during flexion and extension movements. Others are: lack of the Osboune fascia leading to ulnar nerve instability and focal soft tissue tumors (fibromas, lipomas, etc). Recurrent subluxation of the nerve at the elbow results in a tractional and frictional neuritis with classical symptoms of peripheral neuralgia. As far as we know snapping triceps syndrome had never been evaluated in sonoelastography. A 28yo semi-professional left handed tennis player was complaining about pain in posterior-medial elbow area. Initial US examination suggest golfers elbow syndrome which occurs quite commonly and has a prevalence of 0.3–0.6% in males and 0–3–1.1% in women and may be associated (approx. 50% of cases) with ulnar neuropathy. However subsequently made MRI revealed unusual distal triceps anatomy, moderate ulnar nerve swelling and lack of medial epicondylitis symptoms. Followed (second) US examination and sonoelastography have detected slipping of the both ulnar nerve and the additional band of the medial triceps head. Snapping elbow syndrome is a poorly known medical condition, sometimes misdiagnosed as the medial epicondylitis. It describes a broad range of pathologies and anatomical abnormalities. One of the most often reasons is the slipping of the ulnar nerve as the result of the Osborne fascia/anconeus epitrochlearis muscle absence. Simultaneously presence of two or more “snapping reasons” is rare but should be always taken under consideration. There are no sonoelastography studies describing golfers elbow syndrome

  18. Low-temperature-grown InGaAs quantum wells for optical device applications

    Science.gov (United States)

    Juodawlkis, Paul William

    1999-11-01

    The large optical absorption and carrier-induced nonlinearities of semiconductor materials are useful for optical signal processing applications. For absorptive devices operating at ultrafast data rates (>100 Gb/s) or high optical intensities, it is necessary to reduce the intrinsic photo-excited carrier removal time. One method of achieving this reduction is to increase the nonradiative recombination rate through the controlled introduction of defects. In this thesis, we explore the use of low-temperature molecular-beam epitaxy (MBE) to introduce nonradiative recombination centers into InGaAs-based quantum-wells (QWs). The objectives of the thesis are: (i)to improve the understanding of the optoelectronic properties of low-temperature-grown (LTG) InGaAs/InAlAs QWs, and (ii)to assess the feasibility of using these materials for optical device applications in the 1.5-μm wavelength region. Time-resolved differential transmission measurements reveal that the nonlinear absorption recovery time in InGaAs/InAlAs QWs can be reduced from >100 ps to 0.6 ps through the combination of low-temperature growth (~250°C) and beryllium (Be) doping. The bandedge absorption slope and the nonlinear absorption cross- section are only diminished by factors of 2 to 3 relative to QWs grown at standard temperature (~500°C). The Be doping dependence of the recovery time and the residual electron density in the LTG-QWs can be mainly attributed to impurity-related compensation. Be doping also maintains the ultrafast recovery following thermal anneal. The recovery response results from fast electron- trapping followed by slow (>100 ps) trapped- electron/free-hole recombination. Detailed simulations of the nonlinear absorption saturation and recovery processes agree quantitatively with measured data and substantiate the importance of the photo-excitation wavelength on the observed recovery response. The absorption saturation model includes the competition between band-filling and band

  19. Low threshold current and widely tunable external cavity lasers with chirped multilayer InAs/InGaAs/GaAs quantum-dot structure.

    Science.gov (United States)

    Lin, Gray; Su, Pei-Yin; Cheng, Hsu-Chieh

    2012-02-13

    Low threshold and widely tunable InAs/GaAs quantum-dot lasers are implemented with grating-coupled external-cavity arrangement. Throughout the tuning range of 130 nm, from 1160 to 1290 nm, the threshold current density is not more than 0.9 kA/cm2 and no noticeable threshold jump is observed. For a shorter-cavity device, the injection current is kept at a record low value of 90 mA but the tuning range is further extended to 150 nm, from 1143 to 1293 nm. The effect of cavity length on the tuning characteristics is discussed and the strategy for design and optimization of multilayer quantum-dot structure is also proposed. PMID:22418150

  20. Helicobacter pylori infection and low serum pepsinogen I level as risk factors for gastric carcinoma

    Institute of Scientific and Technical Information of China (English)

    Arto Kokkola; Johanna Louhimo; Pauli Puolakkainen; Henrik Alfthan; Caj Haglund; Hilpi Rautelin

    2005-01-01

    AIM: To study whether examination of CagA antibodies could increase the odds ratio for gastric cancer in a casecontrol study, and how often other serum markers of gastric cancer risk could be found in Helicobacter pylorinegative patients.METHODS: H pylori CagA and parietal cell antibodies(PCAs), and serum pepsinogen Ⅰ (SPGI) levels were compared between patients with gastric cancer and controls who received endoscopic examination due to reasons other than gastrointestinal malignancy.RESULTS: The odds ratio (OR) for gastric cancer was2.9 (95% CI 1.4-5.8) in H pylori+ patients, and 2.4 (95%CI 1.2-4.9) in CagA+ patients. When results of H pylori and CagA antibodies were combined, OR increased to5.0 (95% CI 2.5-10.0). Furthermore, if cardia cancer patients were excluded, the OR increased to 6.8 (95% CI3.1-14.8). Among patients with a low SPGI level, the OR was 12.0 (95% CI 4.1-35.3). However, the risk was significant only in the older age group. The number of patients with low SPGI was significantly higher in H pylori-/CagA+ patients as compared to other cancer patients.CONCLUSION: Examination of both H pylori and CagA antibodies increases the OR for gastric cancer in our casecontrol study. CagA antibodies are important in detecting previous H pylori infection in advanced atrophic gastritis or cancer when spontaneous decline of H pylori antibodies occurs. SPGI may be helpful in screening elderly gastric cancer patients.

  1. Juxtaposing Math Self-Efficacy and Self-Concept as Predictors of Long-Term Achievement Outcomes

    Science.gov (United States)

    Parker, Philip David; Marsh, Herbert W.; Ciarrochi, Joseph; Marshall, Sarah; Abduljabbar, Adel Salah

    2014-01-01

    In this study, we tested the hypothesis that self-efficacy and self-concept reflect different underlying processes and both are critical to understanding long-term achievement outcomes. Although both types of self-belief are well established in educational psychology, research comparing and contrasting their relationship with achievement has been…

  2. The Intersections of Living-Learning Programs and Social Identity as Factors of Academic Achievement and Intellectual Engagement

    Science.gov (United States)

    Pasque, Penny A.; Murphy, Rena

    2005-01-01

    Findings from this study show that living-learning (LL) programs at a research institution in the Midwest have a series of positive outcomes for both academic achievement and intellectual engagement. Controlling for past academic achievement, socioeconomic status, and demographic characteristics, LL programs are predictors, albeit small…

  3. Parental Behaviors and Adolescents' Achievement Goals at the Beginning of Middle School: Emotional Problems as Potential Mediators

    Science.gov (United States)

    Duchesne, Stephane; Ratelle, Catherine

    2010-01-01

    Recent literature on the determinants of academic motivation has shown that parenting and emotions are central elements in understanding students' achievement goals. The authors of this study set out to examine the predictive relationship between parental behaviors during the last year of elementary school and adolescents' achievement goals at the…

  4. Independence Training and School Achievement: A Study of Parental Attitudes and Expectations as Related to Children's Elementary School Success.

    Science.gov (United States)

    Wyman, W. C.; And Others

    In this study of the relationship between factors in the home and school achievement, teachers' ratings and student scores on a standard achievement test were examined in light of parental expectations for the child's independence behavior, the child's personal qualities, and his future work values. Mothers of 441 fifth graders were interviewed…

  5. "I'm Not Doing as Well in This Class as I'd Like to": Exploring Achievement Motivation and Personality

    Science.gov (United States)

    Cole, James S.; Denzine, Gypsy M.

    2004-01-01

    This study looked at the relationship of explanatory style and self-systems (including self-esteem and self-efficacy) and the motivation (expectations for success and task value) of students who were dissatisfied with their performance in a particular class. One result is the confirmation that situated variables such as self-efficacy provide the…

  6. Nature of Science and Scientific Inquiry as Contexts for the Learning of Science and Achievement of Scientific Literacy

    Science.gov (United States)

    Lederman, Norman G.; Lederman, Judith S.; Antink, Allison

    2013-01-01

    Although the reasons for concern about quality differ from nation to nation, the primary rallying point for science education reform is the perceived level of scientific literacy among a nation's populace. The essential nature of scientific literacy is that which influences students' decisions about personal and societal problems. Beyond this,…

  7. Low temperature processed metal-semiconductor-metal photodetectors on ZnSe/SI-GaAs (100)

    International Nuclear Information System (INIS)

    Low temperature (LT) processed ZnSe MSM photodetectors can be used for detecting gamma rays or X-rays using scintillation crystals in many space and medical applications. Metal-semiconductor-metal (MSM) photodetectors were fabricated on undoped ZnSe grown by molecular beam epitaxy (MBE) on semi-insulating (100) GaAs substrates. The MSM photodetectors consist of interdigitated metal fingers with 2 microm, 3 microm, and 4 microm spacing on one chip. Probimide and SiO2 thin films were deposited to aid the LT lift-off process before the pattern generation. An interdigitated structure was achieved by photolithography and reactive ion etching. Pd Schottky metal was deposited at a substrate temperature near 77 K using a lift-off technique. The LT metallization provides an improved interface between metal and semiconductor interface. Continuous wave signal to noise ratio (SNR) of 1.57 x 104 was obtained for 2 microm interdigitated photodetectors, operated under 180 nW optical power at a wavelength of 400 nm. The detectors showed good Dc saturation characteristics indicating a low surface recombination. Saturation current without illumination remained at around less than 1 pA for a ± 10 V biasing. Detectors exhibited linearity with light intensity and DC bias voltage suggesting no gain mechanism involved, and showed a high spectral responsivity (0.6 (A/W)) at a wavelength of 450 nm at 5 V applied bias

  8. Attitudes of practicing nurses as predictors of intended care behavior with persons who are HIV positive: testing the Ajzen-Fishbein Theory of Reasoned Action.

    Science.gov (United States)

    Laschinger, H K; Goldenberg, D

    1993-12-01

    The purpose of this descriptive correlational study was to examine practicing nurses' attitudes, subjective norms, and intentions to care for HIV positive patients, using the Theory of Reasoned Action. One hundred and forty-one subjects completed a questionnaire developed according to guidelines described by Ajzen and Fishbein (1980). Consistent with the theory, nurses' attitudes and subjective norms were found to be significant predictors of intentions to care for persons who are HIV positive (R2 = 0.27). Personal beliefs found to discriminate between intenders and nonintenders were those related to possible consequences for self, family, and friends, but not job-related consequences. Normative beliefs which discriminated between groups were also related to nonprofessional referents' expectations. In addition, qualitative data showed persistent concerns about occupational risk for contracting AIDS. Based on the results of this research, it is recommended that nurse educators in both clinical and academic settings, target specific educational/training interventions to include transmission, prevention, as well as exploration of feelings, attitudes, beliefs, and behavioral intentions about HIV-related topics. Further theory-based research and testing of interventions to change practicing nurses' attitudes and beliefs about HIV disease are advocated.

  9. Highly transparent, low-haze, hybrid cellulose nanopaper as electrodes for flexible electronics

    Science.gov (United States)

    Xu, Xuezhu; Zhou, Jian; Jiang, Long; Lubineau, Gilles; Ng, Tienkhee; Ooi, Boon S.; Liao, Hsien-Yu; Shen, Chao; Chen, Long; Zhu, J. Y.

    2016-06-01

    Paper is an excellent candidate to replace plastics as a substrate for flexible electronics due to its low cost, renewability and flexibility. Cellulose nanopaper (CNP), a new type of paper made of nanosized cellulose fibers, is a promising substrate material for transparent and flexible electrodes due to its potentially high transparency and high mechanical strength. Although CNP substrates can achieve high transparency, they are still characterized by high diffuse transmittance and small direct transmittance, resulting in high optical haze of the substrates. In this study, we proposed a simple methodology for large-scale production of high-transparency, low-haze CNP comprising both long cellulose nanofibrils (CNFs) and short cellulose nanocrystals (CNCs). By varying the CNC/CNF ratio in the hybrid CNP, we could tailor its total transmittance, direct transmittance and diffuse transmittance. By increasing the CNC content, the optical haze of the hybrid CNP could be decreased and its transparency could be increased. The direct transmittance and optical haze of the CNP were 75.1% and 10.0%, respectively, greatly improved from the values of previously reported CNP (31.1% and 62.0%, respectively). Transparent, flexible electrodes were fabricated by coating the hybrid CNP with silver nanowires (AgNWs). The electrodes showed a low sheet resistance (minimum 1.2 Ω sq-1) and a high total transmittance (maximum of 82.5%). The electrodes were used to make a light emitting diode (LED) assembly to demonstrate their potential use in flexible displays.Paper is an excellent candidate to replace plastics as a substrate for flexible electronics due to its low cost, renewability and flexibility. Cellulose nanopaper (CNP), a new type of paper made of nanosized cellulose fibers, is a promising substrate material for transparent and flexible electrodes due to its potentially high transparency and high mechanical strength. Although CNP substrates can achieve high transparency, they are

  10. Mobility: A Multivariate Study of Academic Achievement in Reading and Math for Eighth-Grade Students as Measured by the Tennessee Comprehensive Assessment Program

    Science.gov (United States)

    Donnelly, Margaret M.

    2010-01-01

    The primary purpose of this study was to determine if there was a difference between levels of student mobility in reading and mathematics achievement as measured by the 2007-2008 Tennessee Comprehensive Assessment Program (TCAP) achievement test. The study also sought to determine if there existed a difference in socioeconomic and attendance…

  11. International Space Station as a Platform for Exploration Beyond Low Earth Orbit

    Science.gov (United States)

    Raftery, Michael; Woodcock, Gordon

    2010-01-01

    The International Space Station (ISS) has established a new model for the achievement of the most difficult engineering goals in space: international collaboration at the program level with competition at the level of technology. This strategic shift in management approach provides long term program stability while still allowing for the flexible evolution of technology needs and capabilities. Both commercial and government sponsored technology developments are well supported in this management model. ISS also provides a physical platform for development and demonstration of the systems needed for missions beyond low earth orbit. These new systems at the leading edge of technology require operational exercise in the unforgiving environment of space before they can be trusted for long duration missions. Systems and resources needed for expeditions can be aggregated and thoroughly tested at ISS before departure thus providing wide operational flexibility and the best assurance of mission success. We will describe representative mission profiles showing how ISS can support exploration missions to the Moon, Mars, asteroids and other potential destinations. Example missions would include humans to lunar surface and return, and humans to Mars orbit as well as Mars surface and return. ISS benefits include: international access from all major launch sites; an assembly location with crew and tools that could help prepare departing expeditions that involve more than one launch; a parking place for reusable vehicles; and the potential to add a propellant depot.

  12. Comparing Self-Regulatory and Early Academic Skills as Predictors of Later Math, Reading, and Science Elementary School Achievement

    Science.gov (United States)

    Murrah, William M., III

    The achievement score gaps between advantaged and disadvantaged children at school entry is a major problem in education today. Identifying the skills critical for school readiness is an important step in developing interventions aimed at addressing these score gaps. The purpose of this study is to compare a number of school readiness skills with an eye toward finding out which are the best predictors of later academic achievement in math, reading, and science. The predictors were early reading, math, general knowledge, socioemotional skills, and motor skills. Data were obtained from the Early Childhood Longitudinal Study of 1998 (NCES, 1998) database. While controlling for an extensive set of family characteristics, predictions were made across five years - from the end of kindergarten to the end of fifth grade. Consistent with current findings, reading and math skills predicted later achievement. Interestingly, general knowledge, attention, and fine motor skills also proved to be important predictors of later academic achievement, but socioemotional skills were not. The findings were interpreted from a neurobiological perspective involving the development of self-regulation. These school entry skills are used to predict later achievement in reading, math, and science. I argued that in addition to acquiring early academic knowledge, children need to regulate the use of this knowledge to meet academic goals.

  13. Cognitive Training for Children: Effects on Inductive Reasoning, Deductive Reasoning, and Mathematics Achievement in an Australian School Setting

    Science.gov (United States)

    Barkl, Sophie; Porter, Amy; Ginns, Paul

    2012-01-01

    Inductive reasoning is a core cognitive process of fluid intelligence, predicting a variety of educational outcomes. The Cognitive Training for Children (CTC) program is an educational intervention designed to develop children's inductive reasoning skills, with previous investigations finding substantial effects of the program on both inductive…

  14. Attitudes and normative beliefs of nursing students as predictors of intended care behaviors with AIDS patients: a test of the Ajzen-Fishbein theory of reasoned action.

    Science.gov (United States)

    Goldenberg, D; Laschinger, H

    1991-03-01

    Few investigators have studied nurses' or nursing students' responses to caring for AIDS patients. The purpose of this exploratory study was to test the Ajzen-Fishbein (1980) Theory of Reasoned Action in a student nurse population about AIDS patient care. This theory offers an approach to explaining individuals' intentions to engage in certain behaviors as determined by two components: attitudes toward the behavior and subjective norms. Forty-six second-year baccalaureate nursing students completed a questionnaire developed according to guidelines described by Ajzen and Fishbein (alpha reliability range was .69-.85) prior to and following an instructional unit on caring for AIDS patients. Consistent with the theory, students' attitudes and subjective norms were found to be significant predictors of intentions to care for AIDS patients in their clinical experience (R2 = .29, F[1, 43] = 6.63, p less than .003). In addition, qualitative data resembled those in previous reports of fear of contagion among health professionals. The effects of the instructional unit about caring for AIDS patients resulted in significant changes in both attitudes and subjective norms.

  15. Nature of Science and Scientific Inquiry as Contexts for the Learning of Science and Achievement of Scientific Literacy

    OpenAIRE

    Lederman, Norman G.; Lederman, Judith S.; Antink, Allison

    2013-01-01

    Although the reasons for concern about quality differ from nation to nation, the primary rallying point for science education reform is the perceived level of scientific literacy among a nation’s populace. The essential nature of scientific literacy is that which influences students’ decisions about personal and societal problems. Beyond this, however, educators work to influence students’ ability to view science through a more holistic lens. Examining the philosophy, history, and socio...

  16. In situ co-crystallisation as a tool for low-temperature crystal engineering

    DEFF Research Database (Denmark)

    Bond, Andrew D

    2003-01-01

    Synthesis and single-crystal X-ray diffraction of a series of low-melting co-crystals of pyrazine and n-alkyl carboxylic acids demonstrates in situ co-crystallisation as a versatile tool for low-temperature crystal engineering.......Synthesis and single-crystal X-ray diffraction of a series of low-melting co-crystals of pyrazine and n-alkyl carboxylic acids demonstrates in situ co-crystallisation as a versatile tool for low-temperature crystal engineering....

  17. Psychological distress and student engagement as mediators of the relationship between peer victimization and achievement in middle school youth.

    Science.gov (United States)

    Totura, Christine M Wienke; Karver, Marc S; Gesten, Ellis L

    2014-01-01

    Peer victimization is a well-known national and international problem, contributing to a range of emotional, social, and behavioral consequences. Using structural equation modeling, the authors tested a theoretical model suggesting that psychological distress and student engagement mediate the association between the experience of victimization and concurrent academic achievement. Participants were 469 (46.4 % male, 53.6 % female) 6th to 8th grade students, from randomly selected classrooms in 11 middle schools in a southeastern school district. Structural equation models of the hypothesized effects demonstrated adequate fit to the data, with both symptoms of psychological distress and engagement mediating the relationship between victimization and academic achievement. In general, the results suggest that victimization predicts diminished academic achievement by way of psychological distress and poorer engagement in classroom and academic tasks. However, the direct relationship between victimization and measures of achievement lacked significance across many correlational and path analyses conducted. These findings have implications for researchers and practitioners in understanding how psychological distress and student engagement are associated with the academic performance of students who experience peer victimization.

  18. Grandparents as Primary Caregivers and Their Effects on the Reading Achievement of Their Elementary-Age African American Grandchildren

    Science.gov (United States)

    Garry, Vanessa B.

    2009-01-01

    Using data collected from surveys completed by grandparents for their grandchildren (N = 72), this quantitative study examines the effects grandparent primary caregivers have on the reading achievement of their African American grandchildren. The study sought to answer the following question: How do the six types of parental involvement (Epstein,…

  19. School Librarian Staffing Levels and Student Achievement as Represented in 2006-2009 Kansas Annual Yearly Progress Data

    Science.gov (United States)

    Dow, Mirah J.; McMahon-Lakin, Jacqueline

    2012-01-01

    To address the presence or absence of school librarians in Kansas public schools, a study using analysis of covariance (ANCOVA) was designed to investigate staffing levels for library media specialists (LMSs), the label used for school librarians in licensed-personnel data in Kansas, and student achievement at the school level. Five subject areas…

  20. Academic Achievements, Behavioral Problems, and Loneliness as Predictors of Social Skills among Students with and without Learning Disorders

    Science.gov (United States)

    Zach, Sima; Yazdi-Ugav, Orly; Zeev, Aviva

    2016-01-01

    This study aimed to examine to what extent academic achievements, learning disorders, behavior problems and loneliness explain the variance of students' social skills. The differences between students diagnosed with learning disorders and students without learning disorders in all four variables were examined. Participants were 733 elementary…

  1. A Study of Motivation and Other Factors as Relating to Course Achievement in Introductory College Biology, Chemistry, and Physics.

    Science.gov (United States)

    Pridmore, Brooke M.; Halyard, Rebecca A.

    Results of a preliminary study that examined various factors relating to achievement in introductory level biology, chemistry, and physics classes at a public junior college are presented. Background variables, including age, sex, college major, grade point average, SAT-Verbal and SAT-Quantitative, and the sixteen-part scores of Academic…

  2. Conscientiousness, Achievement Striving, and Intelligence as Performance Predictors in a Sample of German Psychology Students: Always a Linear Relationship?

    Science.gov (United States)

    Ziegler, Matthias; Knogler, Maximilian; Buhner, Markus

    2009-01-01

    Studies on the interface between cognitive ability (intelligence) and personality in the prediction of academic performance have yielded mixed results so far. Especially an interaction between conscientiousness (and its facet achievement striving) and intelligence has been investigated. The hypothesis is that conscientiousness enhances the impact…

  3. Neurofeedback as an Intervention to Improve Reading Achievement in Students with Attention- Deficit/Hyperactivity Disorder, Inattentive Subtype

    Science.gov (United States)

    La Marca, Jeffry P.; O'Connor, Rollanda E.

    2016-01-01

    Research consistently demonstrates that attention deficits have a deleterious effect on academic achievement. Impairments in attention, and not hyperactivity/impulsivity, are associated with learning difficulties and academic problems in students with attention-deficit/hyperactivity disorder (ADHD). To date, most studies have focused on symptoms…

  4. Mercer's Adaptive Behavior Inventory, the McCarthy Scales, and Dental Development as Predictors of First-Grade Achievement.

    Science.gov (United States)

    Harrison, Patti L.

    1981-01-01

    The relationship between four characteristics of children entering first grade (cognitive, dental and motor development, and adaptive behavior) and achievement at the end of the first grade year were determined. Interrelationships among the independent variables were also determined. (Author/GK)

  5. The effects of using diagramming as a representational technique on high school students' achievement in solving math word problems

    Science.gov (United States)

    Banerjee, Banmali

    Methods and procedures for successfully solving math word problems have been, and continue to be a mystery to many U.S. high school students. Previous studies suggest that the contextual and mathematical understanding of a word problem, along with the development of schemas and their related external representations, positively contribute to students' accomplishments when solving word problems. Some studies have examined the effects of diagramming on students' abilities to solve word problems that only involved basic arithmetic operations. Other studies have investigated how instructional models that used technology influenced students' problem solving achievements. Still other studies have used schema-based instruction involving students with learning disabilities. No study has evaluated regular high school students' achievements in solving standard math word problems using a diagramming technique without technological aid. This study evaluated students' achievement in solving math word problems using a diagramming technique. Using a quasi-experimental experimental pretest-posttest research design, quantitative data were collected from 172 grade 11 Hispanic English language learners (ELLS) and African American learners whose first language is English (EFLLs) in 18 classes at an inner city high school in Northern New Jersey. There were 88 control and 84 experimental students. The pretest and posttest of each participating student and samples of the experimental students' class assignments provided the qualitative data for the study. The data from this study exhibited that the diagramming method of solving math word problems significantly improved student achievement in the experimental group (pattention to the creation and labeling of diagrams to represent the mathematics involved in standard word problems. Although Learnertype (ELL, EFLL), Classtype (Bilingual and Mixed), and Gender (Female, Male) were not significant indicators of student achievement, there was

  6. Partnership-Ready Schools: Building Systems and Mindsets for the Achievement Schools to Receive and Utilize Community Organizations as Partners in Student Success

    OpenAIRE

    Sanders, Ansel

    2015-01-01

    Over the last decade, the call for schools to leverage partnerships with community organizations as a means to provide services that will mitigate the effects of poverty in the pursuit of achieving ambitious academic outcomes has gained momentum. The Achievement Schools, a network of five neighborhood schools serving students in Memphis’ Frayser community, has prioritized the development of partnerships as a lever to turn around the academic performance of its schools by ensuring students’ no...

  7. Classroom quality as a predictor of first graders' time in non-instructional activities and literacy achievement.

    Science.gov (United States)

    McLean, Leigh; Sparapani, Nicole; Toste, Jessica R; Connor, Carol McDonald

    2016-06-01

    This study investigated how quality of the classroom learning environment influenced first grade students' (n=533) time spent in two non-instructional classroom activities (off-task and in transition) and their subsequent literacy outcomes. Hierarchical linear modeling revealed that higher classroom quality was related to higher student performance in reading comprehension and expressive vocabulary. Further, classroom quality predicted the amount of time students spent off-task and in transitions in the classroom, with slopes of change across the year particularly impacted. Mediation effects were detected in the case of expressive vocabulary such that the influence of classroom quality on students' achievement operated through students' time spent in these non-instructional activities. Results highlight the importance of overall classroom quality to how students navigate the classroom environment during learning opportunities, with subsequent literacy achievement impacted. Implications for policy and educational practices are discussed. PMID:27268569

  8. Classroom quality as a predictor of first graders' time in non-instructional activities and literacy achievement.

    Science.gov (United States)

    McLean, Leigh; Sparapani, Nicole; Toste, Jessica R; Connor, Carol McDonald

    2016-06-01

    This study investigated how quality of the classroom learning environment influenced first grade students' (n=533) time spent in two non-instructional classroom activities (off-task and in transition) and their subsequent literacy outcomes. Hierarchical linear modeling revealed that higher classroom quality was related to higher student performance in reading comprehension and expressive vocabulary. Further, classroom quality predicted the amount of time students spent off-task and in transitions in the classroom, with slopes of change across the year particularly impacted. Mediation effects were detected in the case of expressive vocabulary such that the influence of classroom quality on students' achievement operated through students' time spent in these non-instructional activities. Results highlight the importance of overall classroom quality to how students navigate the classroom environment during learning opportunities, with subsequent literacy achievement impacted. Implications for policy and educational practices are discussed.

  9. Language and academic achievement: Perspectives on the potential role of indigenous African languages as a lingua academica

    OpenAIRE

    Mbulungeni Madiba

    2013-01-01

    Although research literature abounds with studies that show the importance of language for academic achievement, the potential role of indigenous African languages in the educational sector in South Africa has not been adequately appraised or appreciated. Accordingly, ambivalence is still rife among parents, teachers, learners and government about the use of these languages for academic purposes. This ambivalence is evident from the existing national language education policies, school langua...

  10. Neighborhood Ethnic Density as an Explanation for the Academic Achievement of Ethnic Minority Youth Placed in Neighborhood Disadvantage

    OpenAIRE

    Madyun, Na'im Dr.; Lee, Moosung Dr.

    2010-01-01

    The underachievement of ethnic minority youth from disadvantaged neighborhoods is a pervasive educational issue this nation is facing. Based on an ecological perspective, we examined the contextual effects of neighborhood ethnic density and neighborhood disadvantage on the academic achievement of Hmong immigrant youths. Utilizing hierarchical linear modeling techniques in analyzing 3,185 Hmong and White students (for comparisons) across 79 neighborhoods, we found when we controlled for studen...

  11. Effects of reciprocal teaching: A two-year intervention study among low achieving adolescents

    NARCIS (Netherlands)

    Okkinga, Mariska; Gelderen, van Amos; Sleegers, Peter; Steensel, van Roel

    2015-01-01

    Low achieving adolescents are known to have difficulties with reading comprehension. This presentation discusses how reciprocal teaching can improve low achieving adolescents' reading comprehension in natural classroom settings (as opposed to small-group settings) and to what extent intervention eff

  12. Academic Attitudes of High Achieving and Low Achieving Academically Able Black Male Adolescents.

    Science.gov (United States)

    Trotter, John Rhodes

    1981-01-01

    In order to identify the relationships between the attitudes and perceptions of peer pressure and the academic achievement of academically able male adolescents, this study compares the school attitudes of high achieving and low achieving Black male youth. (EF)

  13. Cost recovery as a policy instrument to achieve sustainable and equitable water use in Europe and the Netherlands

    NARCIS (Netherlands)

    Lindhout, P.E.

    2015-01-01

    In this research the author reflected upon the economic environmental instrument of cost recovery for water services as provided for in the WFD. These reflections were made in order to address the question ‘What is the aim of the cost recovery provision in the WFD and what obscurities arise in its i

  14. Learning about Teaching the Extracurricular Topic of Nanotechnology as a Vehicle for Achieving a Sustainable Change in Science Education

    Science.gov (United States)

    Blonder, Ron; Mamlok-Naaman, Rachel

    2016-01-01

    This study focused on teachers' transfer of a variety of teaching methods from a teaching module on nanotechnology, which is an example of a topic outside the science curriculum, to teaching topics that are part of the chemistry curriculum. Nanotechnology is outside the science curriculum, but it was used in this study as a means to carry out a…

  15. An Analysis of Teacher and School Administrator Technology Beliefs and Skills as They Enter into a High Achieving Schools Program

    Science.gov (United States)

    Hildebrand, Shelly Marie

    2009-01-01

    Teachers and administrators possess varied technology abilities and beliefs. In a study by Williams, Atkinson, Cate, and O'Hair (2008), technology integration and learning community development were positively related. As the teachers and administrators engaged in learning community development and technology integration substantive school…

  16. The Relationship between Anxiety and Attitude of Students Learning Turkish as a Foreign Language and Their Achievement on Target Language

    Science.gov (United States)

    Gocer, Ali

    2014-01-01

    The purpose of this study is to assess the anxiety connected with target language of the high school students learning Turkish as a foreign language. In this study, descriptive relational screening model was used. Two scales were used for collecting data. First scale was FLCAS-Foreign Language Classroom Anxiety Scale; it was developed by Horwitz…

  17. Views from the Field: Conservation Educators' and Practitioners' Perceptions of Education as a Strategy for Achieving Conservation Outcomes

    Science.gov (United States)

    Ardoin, Nicole M.; Heimlich, Joe E.

    2013-01-01

    This article presents data from a mixed-methods study that collected data through surveys (n = 656), interviews (n = 15), and discussion groups (n = 75) to explore the use of social strategies such as education and outreach by non-governmental organizations and government agencies to reach outcomes related to biodiversity conservation and resource…

  18. Characterization of Femtosecond Low-Temperature-Grown GaAs Photoconductive Switch

    Institute of Scientific and Technical Information of China (English)

    林位株; 刘智刚; 廖睿; 张海潮; 郭冰; 文锦辉; 赖天树

    2002-01-01

    A photoconductive response time, as short as 350 fs, of a low-temperature-grown GaAs (LT-GaAs) micro-coplanar photoconductive switch has been measured and modelled to the ultrafast trapping of the photoexcited carriers in LT-GaAs. The coherent interference of the pump and probe pulses results in a narrow spike photocurrent autocorrelation signal which maps the femtosecond optical pulses.

  19. The effectiveness of walking as an intervention for low back pain: a systematic review

    OpenAIRE

    Hendrick, P; Te Wake, A. M.; Tikkisetty, A. S.; Wulff, L.; Yap, C.; Milosavljevic, S.

    2010-01-01

    As current low back pain (LBP) guidelines do not specifically advocate walking as an intervention, this review has explored for the effectiveness of walking in managing acute and chronic LBP. CINAHL, Medline, AMED, EMBASE, PubMed, Cochrane and Scopus databases, as well as a hand search of reference lists of retrieved articles, were searched. The search was restricted to studies in the English language. Studies were included when walking was identified as an intervention. Four studies met incl...

  20. A GaAs monolithic low-noise broad-band amplifier

    Science.gov (United States)

    Archer, J. A.; Weidlich, H. P.; Pettenpaul, E.; Petz, F. A.; Huber, J.

    1981-12-01

    This paper describes the design, fabrication, and performance of GaAs monolithic low-noise broad-band amplifiers intended for broadcast receiver antenna amplifier, IF amplifier, and instrumentation applications. The process technology includes the use of Czochralski-grown semiinsulating substrates, localized implantation of ohmic and FET channel regions, and silicon nitride for passivation and MIM capacitors. The amplifiers employ shunt feedback to obtain input matching and flat broad-band response. One amplifier provides a gain of 24 dB, bandwidth of 930 MHz, and noise figure of 5.0 dB. A second amplifier provides a gain of 17 dB, bandwidth of 1400 MHz, and noise figure of 5.6 dB. Input and output VSWR's are typically less than 2:1 and the third-order intercept points are 28 and 32 dB, respectively. Improved noise figure and intercept point can be achieved by the use of external RF chokes.

  1. NANOPARTICLES OF TUNGSTEN AS LOW-COST MONOMETALLIC CATALYST FOR SELECTIVE HYDROGENATION OF 3-HEXYNE

    Directory of Open Access Journals (Sweden)

    María Juliana Maccarrone

    2016-01-01

    Full Text Available Low-cost tungsten monometallic catalysts containing variable amounts of metal (4.5, 7.1 and 8.5%W were prepared by impregnating alumina with ammonium metatungstate as an inexpensive precursor. The catalysts were characterized using ICP, XPS, XRD, TPR and hydrogen chemisorption. These techniques revealed mainly WO3-Al2O3 (W6+ species on the surface. The effects of the content of W nanoparticles and reaction temperature on activity and selectivity for the partial hydrogenation of 3-hexyne, a non-terminal alkyne, were assessed under moderate conditions of temperature and pressure. The monometallic catalysts prepared were found to be active and stereoselective for the production of (Z -3-hexene, had the following order: 7.1WN/A > 8.5 WN/A ≥ 4.5 WN/A. Additionally, the performance of the synthesized xWN/A catalysts exhibited high sensitivity to temperature variation. In all cases, the maximum 3-hexyne total conversion and selectivity was achieved at 323 K. The performance of the catalysts was considered to be a consequence of two phenomena: a the electronic effects, related to the high charge of W (+6, causing an intensive dipole moment in the hydrogen molecule (van der Waals forces and leading to heterolytic bond rupture; the H+ and H- species generated approach a 3-hexyne adsorbate molecule and cause heterolytic rupture of the C≡C bond into C- = C+; and b steric effects related to the high concentration of WO3 on 8.5WN/A that block the Al2O3 support. Catalyst deactivation was detected, starting at about 50 min of reaction time. Electrodeficient W6+ species are responsible for the formation of green oil at the surface level, blocking pores and active sites of the catalyst, particularly at low reaction temperatures (293 and 303 K. The resulting best catalyst, 7.1WN/A, has low fabrication cost and high selectivity for (Z -3-hexene (94% at 323 K. This selectivity is comparable to that of the classical and more expensive industrial Lindlar catalyst

  2. Progress on the Low-Latency Inspiral Gravitational Wave Detection algorithm known as SPIIR

    OpenAIRE

    Hooper, S.; Wen, L; Hanna, C.; Cannon, K; Keppel, D.; Blair, D; Chung, S; Singer, L.; Chen, Y

    2012-01-01

    Low-latency event triggers to signify the presence of gravitational waves from coalescing binaries will be required to make prompt electromagnetic follow-up observations of electromagnetic counterparts. We present the recent progress made on implementing the time-domain low-latency detection algorithm known as summed parallel infinite impulse response (SPIIR) filtering into a real gravitational wave search pipeline.

  3. Low-water activity foods: increased concern as vehicles of foodborne pathogens

    NARCIS (Netherlands)

    Beuchat, L.R.; Komitopoulou, E.; Beckers, H.; Betts, R.P.; Bourdichon, F.; Fanning, S.; Joosten, H.M.L.J.; Kuile, ter B.H.

    2013-01-01

    Foods and food ingredients with low water activity (aw) have been implicated with increased frequency in recent years as vehicles for pathogens that have caused outbreaks of illnesses. Some of these foodborne pathogens can survive for several months, even years, in low-aw foods and in dry food proce

  4. Ultra-low dark current InGaAs technology for focal plane arrays for low-light level visible-shortwave infrared imaging

    Science.gov (United States)

    Onat, Bora M.; Huang, Wei; Masaun, Navneet; Lange, Michael; Ettenberg, Martin H.; Dries, Christopher

    2007-04-01

    Under the DARPA Photon Counting Arrays (PCAR) program we have investigated technologies to reduce the overall noise level in InGaAs based imagers for identifying a man at 100m under low-light level imaging conditions. We report the results of our experiments comprising of 15 InGaAs wafers that were utilized to investigate lowering dark current in photodiode arrays. As a result of these experiments, we have achieved an ultra low dark current of 2nA/cm2 through technological advances in InGaAs detector design, epitaxial growth, and processing at a temperature of +12.3 degrees C. The InGaAs photodiode array was hybridized to a low noise readout integrated circuit, also developed under this program. The focal plane array (FPA) achieves very high sensitivity in the shortwave infrared bands in addition to the visible response added via substrate removal process post hybridization. Based on our current room-temperature stabilized SWIR camera platform, these imagers enable a full day-night imaging capability and are responsive to currently fielded covert laser designators, illuminators, and rangefinders. In addition, improved haze penetration in the SWIR compared to the visible provides enhanced clarity in the imagery of a scene. In this paper we show the results of our dark current studies as well as FPA characterization of the camera built under this program.

  5. The use of electronic collars for training domestic dogs: estimated prevalence, reasons and risk factors for use, and owner perceived success as compared to other training methods

    Directory of Open Access Journals (Sweden)

    Blackwell Emily J

    2012-06-01

    Full Text Available Abstract Background The use of electronic training devices for dog training is controversial. The aims of this study were to give an indication of the extent to which dog owners use these devices in England, identify factors associated with their use, and compare owner report of outcomes. A convenience sample of dog owners in England was used to identify numbers using electronic training devices and identify reasons for use. Factors associated with use of remote e-collars only were determined by comparing dogs trained using these devices with two control populations matched for reason of use (recall / chasing problems. Comparison groups were: those using other ‘negative reinforcement / positive punishment’ training techniques, and those using ‘positive reinforcement / negative punishment’ based methods. A multinominal logistic regression model was used to compare factors between categories of training method. Owner reported success for use was compared using chi-squared analysis. Results For England only, 3.3% (n = 133 owners reported using remote activated e-collars, 1.4% (n = 54 reported use of bark activated e-collars, and 0.9% (n = 36 reported using electronic boundary fences. In comparison with the e-collar group, owners using reward based training methods for recall / chasing were 2.8 times more likely to be female and 2.7 times less likely to have attended agility training. Owners using other aversive methods for recall / chasing were 2.8 times more likely to have attended puppy classes than those using e-collars. However, the model only explained 10% variance between groups. A significantly higher proportion of owners in the reward group reported training success than those in the e-collar group. Conclusions In conclusion, a fairly low proportion of owners select to use electronic training devices. For a population matched by reason for training method use, characteristics of dogs, including occurrence of undesired

  6. Low temperature transport in p-doped InAs nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, S.; Jespersen, T. S.; Madsen, M. H.; Krogstrup, P.; Nygård, J. [Center for Quantum Devices and Nano-Science Center, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen (Denmark)

    2013-10-14

    We present low temperature electrical measurements of p-type Indium Arsenide nanowires grown via molecular beam epitaxy using Beryllium as a dopant. Growth of p-type wires without stacking faults is demonstrated. Devices in field-effect geometries exhibit ambipolar behavior, and the temperature dependence of electron and hole field effect mobilities are extracted. At low temperatures, we observe reproducible conductance fluctuations as a result of quantum interference, and magnetoconductance data show weak antilocalization.

  7. Ohmic contact formation process on low n-type gallium arsenide (GaAs) using indium gallium zinc oxide (IGZO)

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seong-Uk [Samsung-SKKU Graphene Center and School of Electronics and Electrical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Product and Test Engineering Team, System LSI Division, Samsung Electronics Co., Ltd, Yongin 446-711 (Korea, Republic of); Jung, Woo-Shik [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States); Lee, In-Yeal; Jung, Hyun-Wook; Kim, Gil-Ho [Samsung-SKKU Graphene Center and School of Electronics and Electrical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Park, Jin-Hong, E-mail: jhpark9@skku.edu [Samsung-SKKU Graphene Center and School of Electronics and Electrical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-02-01

    Highlights: • We propose a method to fabricate non-gold Ohmic contact on low n-type GaAs with IGZO. • 0.15 A/cm{sup 2} on-current and 1.5 on/off-current ratio are achieved in the junction. • InAs and InGaAs formed by this process decrease an electron barrier height. • Traps generated by diffused O atoms also induce a trap-assisted tunneling phenomenon. - Abstract: Here, an excellent non-gold Ohmic contact on low n-type GaAs is demonstrated by using indium gallium zinc oxide and investigating through time of flight-secondary ion mass spectrometry, X-ray photoelectron spectroscopy, transmission electron microscopy, J–V measurement, and H [enthalpy], S [entropy], Cp [heat capacity] chemistry simulation. In is diffused through GaAs during annealing and reacts with As, forming InAs and InGaAs phases with lower energy bandgap. As a result, it decreases the electron barrier height, eventually increasing the reverse current. In addition, traps generated by diffused O atoms induce a trap-assisted tunneling phenomenon, increasing generation current and subsequently the reverse current. Therefore, an excellent Ohmic contact with 0.15 A/cm{sup 2} on-current density and 1.5 on/off-current ratio is achieved on n-type GaAs.

  8. Ohmic contact formation process on low n-type gallium arsenide (GaAs) using indium gallium zinc oxide (IGZO)

    International Nuclear Information System (INIS)

    Highlights: • We propose a method to fabricate non-gold Ohmic contact on low n-type GaAs with IGZO. • 0.15 A/cm2 on-current and 1.5 on/off-current ratio are achieved in the junction. • InAs and InGaAs formed by this process decrease an electron barrier height. • Traps generated by diffused O atoms also induce a trap-assisted tunneling phenomenon. - Abstract: Here, an excellent non-gold Ohmic contact on low n-type GaAs is demonstrated by using indium gallium zinc oxide and investigating through time of flight-secondary ion mass spectrometry, X-ray photoelectron spectroscopy, transmission electron microscopy, J–V measurement, and H [enthalpy], S [entropy], Cp [heat capacity] chemistry simulation. In is diffused through GaAs during annealing and reacts with As, forming InAs and InGaAs phases with lower energy bandgap. As a result, it decreases the electron barrier height, eventually increasing the reverse current. In addition, traps generated by diffused O atoms induce a trap-assisted tunneling phenomenon, increasing generation current and subsequently the reverse current. Therefore, an excellent Ohmic contact with 0.15 A/cm2 on-current density and 1.5 on/off-current ratio is achieved on n-type GaAs

  9. A novel technique to achieve atomic macro-coherence as a tool to determine the nature of neutrinos

    Science.gov (United States)

    Boyero García, R.; Carpentier, A. V.; Gómez-Cadenas, J. J.; Peralta Conde, A.

    2016-10-01

    The photon spectrum in macro-coherent atomic deexcitation via radiative emission of neutrino pairs has been proposed as a sensitive probe of the neutrino mass spectrum, capable of competing with conventional neutrino experiments. In this paper, we revisit this intriguing possibility, presenting an alternative method for inducing large coherence in a target based on adiabatic techniques. More concretely, we propose the use of a modified version of coherent population return (CPR), namely two-photon CPR, that turns out to be extremely robust with respect to the experimental parameters and capable of inducing a coherence close to 100 % in the target.

  10. High Immunization Coverage in Children as One of the Major Achievements for the Health System in Iran

    Directory of Open Access Journals (Sweden)

    Salman Khazaei

    2016-07-01

    Full Text Available Vaccination considered as one of the most cost-effective health interventions worldwide  through prevention and control of many serious childhood diseases (1. It is estimated  global coverage of  Dose 3 of Diphtheria, Tetanus, and Pertussis (DTP3among children one year old has been 86% in 2014 (by range from 77% to 96%  in African Region and Western Pacific Region; respectively (2. Globally in 2014, it is estimated about 18.7 million infants were not receive routine immunization services such as DTP3 vaccine. More than 60% of these children  were living in 10 undeveloped countries (3. Coverage rate the third dose of DTP vaccine (DTP3 in at the age of 12 months is a key indicator of National Immunization Programme (NIP performance; because it reflects completion of the basic infant immunization schedule and coverage with other vaccines (2. In this study we aimed to examine status of immunization coverage in Iran compared to other countries in the world during 1980-2015.

  11. Onset of ferromagnetism in low-doped GaMnAs

    OpenAIRE

    Sheu, B. L.; Myers, R. C.; Tang, J. -M.; Samarth, N.; Awschalom, D. D.; Schiffer, P.; Flatté, M. E.

    2007-01-01

    We develop a quantitatively predictive theory for impurity-band ferromagnetism in the low-doping regime of GaMnAs and compare with experimental measurements of a series of samples whose compositions span the transition from paramagnetic insulating to ferromagnetic conducting behavior. The theoretical Curie temperatures depend sensitively on the local fluctuations in the Mn-hole binding energy, which originates from disorder in the Mn distribution as well as the presence of As antisite defects...

  12. 100 nm AlSb/InAs HEMT for Ultra-Low-Power Consumption, Low-Noise Applications

    Directory of Open Access Journals (Sweden)

    Cyrille Gardès

    2014-01-01

    Full Text Available We report on high frequency (HF and noise performances of AlSb/InAs high electron mobility transistor (HEMT with 100 nm gate length at room temperature in low-power regime. Extrinsic cut-off frequencies fT/fmax of 100/125 GHz together with minimum noise figure NFmin=0.5 dB and associated gain Gass=12 dB at 12 GHz have been obtained at drain bias of only 80 mV, corresponding to 4 mW/mm DC power dissipation. This demonstrates the great ability of AlSb/InAs HEMT for high-frequency operation combined with low-noise performances in ultra-low-power regime.

  13. Polynorbornene as a low loss matrix material for IR metamaterial applications.

    Energy Technology Data Exchange (ETDEWEB)

    Arrington, Christian Lew; Sinclair, Michael B.; Ginn, James Cleveland, III; Lee, Yun-Ju; Sanchez, Andrea E.; Clem, Paul Gilbert; Hines, Paul; Dirk, Shawn M.; Rasberry, Roger D.

    2010-11-01

    Novel low loss photopatternable matrix materials for IR metamaterial applications were synthesized using the ring opening metathesis polymerization reaction (ROMP) of norbornene followed by a partial hydrogenation to remove most of the IR absorbing olefin groups which absorb in the 8-12 {micro}m range. Photopatterning was achieved via crosslinking of the remaining olefin groups with alpha, omega-dithiols via the thiol-ene coupling reaction. Since ROMP is a living polymerization the molecular weight of the polymer can be controlled simply by varying the ratio of catalyst to monomer. In order to determine the optimum photopattenable IR matrix material we varied the amount of olefin remaining after the partial hydrogenation. Hydrogenation was accomplished using tosyl hydrazide. The degree of hydrogenation can be controlled by altering the reaction time or reaction stoichiometry and the by-products can be easily removed during workup by precipitation into ethanol. Several polymers have been prepared using this reduction scheme including two polymers which had 54% and 68% olefin remaining. Free standing films (approx. 12 {micro}m) were prepared from the 68% olefin material using draw-down technique and subsequently irradiated with a UV lamp (365 nm) for thirty minutes to induce crosslinking via thiol-ene reaction. After crosslinking, the olefin IR-absorption band disappeared and the Tg of the matrix material increased; both desirable properties for IR metamaterial applications. The polymer system has inherent photopatternable behavior primarily because of solubility differences between the pre-polymer and cross-linked matrix. Photopatterned structures using the 54% as well as the 68% olefin material were easily obtained. The synthesis, processing, and IR absorption data and the ramifications to dielectric metamaterials will be discussed.

  14. FRANCHISING AS A MEANS OF ACHIEVING INTERNATIONALIZATION: RESEARCH PROPOSITIONS FROM A MULTIPLE CASE STUDY OF BRAZILIAN FASHION RETAILERS

    Directory of Open Access Journals (Sweden)

    Victor Manoel Cunha de Almeida

    2015-12-01

    Full Text Available According to Brazilian Franchising Association, the number of Brazilian franchises has grown 300% in the last ten years, but only 3% of Brazilian franchises operate in foreign markets, so the opportunity to internationalization is strong. Aiming to get a better understanding of possible distinctive features of Brazilian retail internationalization, this paper explores the determinants of franchising as the choice of internationalization entry mode by Brazilian’s firms in the fashion apparel sector. The multiple-case study was the approach used. The study resulted in eleven research propositions. Results show that government or trade organizations support, geographic distance, political and economic risk may not be determinant to internationalization. However cultural proximity and relationship with local partners can be determinant to internationalization. Moreover, brands that cater to a very specific segment and that their value proposition is closely linked to intangible factors may face problems in expanding to culturally distant international environments.

  15. Elements of product service systems as a potential to achieve a sustainable development: bibliometry and content analysis

    Directory of Open Access Journals (Sweden)

    Rafael Ariente Neto

    2014-08-01

    Full Text Available The concept of product-service systems (PSS is presented as an innovative strategy when offering products and services. It aims at for minimizing environmental impacts through sustainable business models. This study aims to identify which potentialities can be explored with regard to the elements of a PSS in a configuration that favor to offer answers on sustainable issues. To do so, the literature was analyzed by a structured process of bibliographic review. Among the results, three aspects are highlighted: (i the wideness of product concept to add services through PSS life-cycle, (ii the configuration of infra-structure to support a PSS by establishing the necessary communication relatively to logistics services. Finally, the net of actors should be explored to obtain organizational proposals that contribute to PSS performance.

  16. Steric repulsion as a way to achieve the required stability for the preparation of ionic liquid-based ferrofluids.

    Science.gov (United States)

    Rodríguez-Arco, Laura; López-López, Modesto T; González-Caballero, Fernando; Durán, Juan D G

    2011-05-01

    With this work we would like to emphasize the necessity of steric repulsion to stabilize novel ionic liquid-based ferrofluids. For this purpose, we prepared a suspension of magnetite nanoparticles coated with a double layer of oleic acid, dispersed in 1-ethyl-3-methylimidazolium ethylsulphate ([EMIM][EtSO(4)]). For comparison, a suspension of bare magnetite nanoparticles in [EMIM][EtSO(4)] was also prepared. The stability of these suspensions was checked by magnetic sedimentation and centrifugation processes. Furthermore, their yield stress was measured as a function of the applied magnetic field, which gave additional information on their stability. The results of these experiments showed that the suspension of bare nanoparticles was rather unstable, whereas the suspension of double layer coated nanoparticles gave rise to a true (stable) ferrofluid. PMID:21345446

  17. Combination of inulin and time dependent polymethacrylates as a coating system to achieve colonic delivery of indomethacin

    Directory of Open Access Journals (Sweden)

    A Akhgari

    2009-10-01

    Full Text Available "n "nBackground:In the previous study it was shown that films prepared from inulin (In in combination with Eudragit RS (ERS and RL (ERL were susceptible to inulinase. Purpose: The aim of this work was to assess the suitability of these combinations for colonic delivery of indomethacin. "nMethods: Indomethacin was loaded onto non-pareil seeds using fluidized bed apparatus to produce pellets with 20% w/w drug load. Drug loaded pellets were coated with In-ERS in the ratios of 20:80 and 30:70, or In-ERL in the ratio of 20:80 to different coating loads. The release of drug was examined in simulated gastric (for 2 hrs and small intestine and in the presence of inulinase in simulated colonic medium (for 12 or 24 hrs. "nResults: The results of this study revealed that incorporation of inulin as a bacterially degradable polysaccharide into ERS or ERL could modulate drug release. Coating level up to 15% significantly affected drug release from In-ERL or In-ERS coated pellets. However further increase in coating load to 20% had no significant effect on drug release from In-ERL coated pellets (f1=9.39. Drug release from In-ERL coated pellets was faster and showed some pH dependency. "nConclusions: Formulation coated with In-ERS (20:80 and coating level of 20% was considered more appropriate for colon delivery of indomethacin, as drug release was pH independent and formulation was resistant to drug release in the upper GI media for up to 7 hrs. This formulation was also susceptible to inulinase and released about 40% of indomethacin in the simulated colonic media.

  18. The effectiveness of walking as an intervention for low back pain: a systematic review.

    Science.gov (United States)

    Hendrick, P; Te Wake, A M; Tikkisetty, A S; Wulff, L; Yap, C; Milosavljevic, S

    2010-10-01

    As current low back pain (LBP) guidelines do not specifically advocate walking as an intervention, this review has explored for the effectiveness of walking in managing acute and chronic LBP. CINAHL, Medline, AMED, EMBASE, PubMed, Cochrane and Scopus databases, as well as a hand search of reference lists of retrieved articles, were searched. The search was restricted to studies in the English language. Studies were included when walking was identified as an intervention. Four studies met inclusion criteria, and were assessed with a quality checklist. Three lower ranked studies reported a reduction in LBP from a walking intervention, while the highest ranked study observed no effect. Heterogeneity of study design made it difficult to draw comparisons between studies. There is only low-moderate evidence for walking as an effective intervention strategy for LBP. Further investigation is required to investigate the strength of effect for walking as a primary intervention in the management of acute and chronic LBP. PMID:20414688

  19. Charge collection efficiency of GaAs detectors studied with low-energy heavy charged particles

    CERN Document Server

    Bates, R; Linhart, V; O'Shea, V; Pospísil, S; Raine, C; Smith, K; Sinor, M; Wilhelm, I

    1999-01-01

    Epitaxially grown GaAs layers have recently been produced with sufficient thickness and low enough free carrier concentration to permit their use as radiation detectors. Initial tests have shown that the epi-material behaves as a classical semiconductor as the depletion behaviour follows the square root dependency on the applied bias. This article presents the results of measurements of the growth of the active depletion depth with increasing bias using low-energy protons and alpha particles as probes for various depths and their comparison to values extrapolated from capacitance measurements. From the proton and alpha particle spectroscopic measurements, an active depth of detector material that collects 100% of the charge generated inside it was determined. The consistency of these results with independent capacitance measurements supports the idea that the GaAs epi-material behaves as a classical semiconductor. (author)

  20. Implementation of production function of labor law as a means of achieving the social stability in Russia

    Directory of Open Access Journals (Sweden)

    Tatyana Aleksandrovna Izbiyenova

    2015-09-01

    Full Text Available Objective to determine the role and importance of the production function in the Russian labor law under modern conditions. Methods general comparative analysis abstraction analysis synthesis and speciallegal methods method of comparative law analysis technicallegal method etc.. Results the study proved the necessity of amendment in the civil law in terms of giving workers39 representatives the right to participate in the work of collective bodies of legal entities. The existing approaches to the formation of the management bodies do not allow to discuss the possibility of successful implementation of the production function of labour law. Scientific novelty for the first time by the examples of industrial democracy implementation in some foreign countries and in the Russian Federation the role and significance of industrial democracy was studied as the form of implementation of the production function of labour law. Practical significance the main provisions and conclusions of the article can be used in research activities when considering the functions of the Russian labour law and also in standardsetting activities for the improvement of normative legal acts. nbsp

  1. EFFECT OF RECYCLE TIRE ISOLATOR AS EARTHQUAKE RESISTANCE SYSTEM FOR LOW RISE BUILDINGS IN MALAYSIA

    Directory of Open Access Journals (Sweden)

    SOW WEI JIE

    2016-08-01

    Full Text Available The purpose of this research is to investigate the effect of Recycle Tire Isolator (RTI as earthquake resistance system for low rise buildings in Malaysia. Most of the earthquake’s victims are due to the collapse of poorly designed concrete and masonry buildings. Therefore, an economical but reliable RTI is introduced to solve the problem in most of the developing countries such as Malaysia. This study focuses on the effect of RTI-5 (5 layers RTI in protecting three stories buildings. The vertical displacement of RTI-5 was determined through static compression test. The maximum vertical displacement of RTI-5 was obtained when the specimen was monotonically loaded to failure. Finite element analysis was carried out by using ANSYS V16.0 to model the RTI-5 and the results obtained were compared to the experimental results. The dynamic stiffness and damping ratio of RTI-5 were investigated through dynamic test. The behaviour of various thickness of RTI were examined and compared with Rubber Bearing (RB and Scrap Tire Rubber Pad (STRP.Total displacement of three stories buildings on fixed base and on base isolation were determined. The results from static compression test and finite element analysis showed that RTI-5 could sustain a vertical load of 380 kN with vertical deformation of 12.5 mm. It has been verified by finite element analysis (FEA where both of the results achieved close agreement in terms of vertical deformation. RTI-5 and STRP have similar vertical stiffness due to the employment of same material in fabrication. However, rubber bearing is stiffer than RTI-5 due to the present of embedded steel plates. Besides, RTI-4 is stiffer than RTI-5 due to the number of layers are lesser in RTI-4. The results of dynamic test shown that RTI-5 has higher damping ratio than RTI-4. In overall, total deformation at the top floor of the three stories building is reduced by 83% via implementation of RTI in the base of the building. It has been proven

  2. Femtosecond differential transmission measurements on low temperature GaAs metal-semiconductor-metal structures

    DEFF Research Database (Denmark)

    Keil, Ulrich Dieter Felix; Hvam, Jørn Märcher; Tautz, S.;

    1997-01-01

    We report on differential transmission measurements on low temperature grown (LT)-GaAs with and without applied electrical fields at different wavelengths. Electrical fields up to 100 kV/cm can be applied via an interdigitated contact structure to our LT GaAs samples which have been removed from ...

  3. Reasons Low-Income Parents Offer Snacks to Children: How Feeding Rationale Influences Snack Frequency and Adherence to Dietary Recommendations

    Directory of Open Access Journals (Sweden)

    Rachel E. Blaine

    2015-07-01

    Full Text Available Although American children snack more than ever before, the parental role in promoting snacking is not well understood. In 2012–2013 at baseline in an intervention study to prevent childhood obesity in low-income Massachusetts communities, n = 271 parents of children aged 2–12 years completed surveys regarding nutritive and non-nutritive reasons they offered children snacks, demographics, and dietary factors. An analysis of variance demonstrated that parents reported offering snacks (mean/week; standard deviation (SD for nutritive reasons like promoting growth (x̄ = 2.5; SD 2.2 or satisfying hunger (x̄ = 2.4; SD 2.1 almost twice as often as non-nutritive reasons like keeping a child quiet (x̄ = 0.7; SD 1.5 or celebrating events/holidays (x̄ = 0.8; SD 1.1. Parents reported giving young children (2–5 years more snacks to reward behavior (1.9 vs. 1.1, p < 0.001, keep quiet (1.0 vs. 0.5, p < 0.001, and celebrate achievements (1.7 vs. 1.0, p < 0.001 than parents of older children (6–12 years. Multivariable logistic regression models were used to obtain adjusted odds ratios, which indicated reduced child adherence to dietary recommendations when parents offered snacks to reward behavior (Odds Ratio (OR = 0.83; 95% Confidence Interval (CI 0.70–0.99, celebrate events/holidays (OR = 0.72; 95% CI 0.52–0.99, or achievements (OR = 0.82; 95% CI 0.68–0.98. Parental intentions around child snacking are likely important targets for obesity prevention efforts.

  4. Assessing the suitability of GIS as an aid for Location Scouting in Low-Budget Filmmaking

    OpenAIRE

    Fuller, Callum

    2010-01-01

    The purpose of this analysis was to assess the suitability of GIS as an aid for location scouting in low-budget filmmaking, with Edinburgh serving as the target area. The main aspect of the project was to create a web based map service to act as a guide for the service user, rather than be a definitive resource. The key to satisfying the target audience of low-budget filmmakers was to gather their input to inform user requirements. Similar services within Edinburgh were researched and no s...

  5. The postgraduate hospital educational environment measure (PHEEM questionnaire identifies quality of instruction as a key factor predicting academic achievement

    Directory of Open Access Journals (Sweden)

    Joaquim Edson Vieira

    2008-01-01

    Full Text Available OBJECTIVE: This study analyzes the reliability of the PHEEM questionnaire translated into Portuguese. We present the results of PHEEM following distribution to doctors in three different medical residency programs at a university hospital in Brazil. INTRODUCTION: Efforts to understand environmental factors that foster effective learning resulted in the development of a questionnaire to measure medical residents' perceptions of the level of autonomy, teaching quality and social support in their programs. METHODS: The questionnaire was translated using the modified Brislin back-translation technique. Cronbach's alpha test was used to ensure good reliability and ANOVA was used to compare PHEEM results among residents from the Surgery, Anesthesiology and Internal Medicine departments. The Kappa coefficient was used as a measure of agreement, and factor analysis was employed to evaluate the construct strength of the three domains suggested by the original PHEEM questionnaire. RESULTS: The PHEEM survey was completed by 306 medical residents and the resulting Cronbach's alpha was 0.899. The weighted Kappa was showed excellent reliability. Autonomy was rated most highly by Internal Medicine residents (63.7% ± 13.6%. Teaching was rated highest in Anesthesiology (66.7% ± 15.4%. Residents across the three areas had similar perceptions of social support (59.0% ± 13.3% for Surgery; 60.5% ± 13.6% for Internal Medicine; 61.4% ± 14.4% for Anesthesiology. Factor analysis suggested that nine factors explained 58.9% of the variance. CONCLUSIONS: This study indicates that PHEEM is a reliable instrument for measuring the quality of medical residency programs at a Brazilian teaching hospital. The results suggest that quality of teaching was the best indicator of overall response to the questionnaire.

  6. In situ low-relief landscape formation as a result of river network disruption.

    Science.gov (United States)

    Yang, Rong; Willett, Sean D; Goren, Liran

    2015-04-23

    Landscapes on Earth retain a record of the tectonic, environmental and climatic history under which they formed. Landscapes tend towards an equilibrium in which rivers attain a stable grade that balances the tectonic production of elevation and with hillslopes that attain a gradient steep enough to transport material to river channels. Equilibrium low-relief surfaces are typically found at low elevations, graded to sea level. However, there are many examples of high-elevation, low-relief surfaces, often referred to as relict landscapes, or as elevated peneplains. These do not grade to sea level and are typically interpreted as uplifted old landscapes, preserving former, more moderate tectonic conditions. Here we test this model of landscape evolution through digital topographic analysis of a set of purportedly relict landscapes on the southeastern margin of the Tibetan Plateau, one of the most geographically complex, climatically varied and biologically diverse regions of the world. We find that, in contrast to theory, the purported surfaces are not consistent with progressive establishment of a new, steeper, river grade, and therefore they cannot necessarily be interpreted as a remnant of an old, low relief surface. We propose an alternative model, supported by numerical experiments, in which tectonic deformation has disrupted the regional river network, leaving remnants of it isolated and starved of drainage area and thus unable to balance tectonic uplift. The implication is that the state of low relief with low erosion rate is developing in situ, rather than preserving past erosional conditions.

  7. In situ low-relief landscape formation as a result of river network disruption

    Science.gov (United States)

    Yang, Rong; Willett, Sean D.; Goren, Liran

    2015-04-01

    Landscapes on Earth retain a record of the tectonic, environmental and climatic history under which they formed. Landscapes tend towards an equilibrium in which rivers attain a stable grade that balances the tectonic production of elevation and with hillslopes that attain a gradient steep enough to transport material to river channels. Equilibrium low-relief surfaces are typically found at low elevations, graded to sea level. However, there are many examples of high-elevation, low-relief surfaces, often referred to as relict landscapes, or as elevated peneplains. These do not grade to sea level and are typically interpreted as uplifted old landscapes, preserving former, more moderate tectonic conditions. Here we test this model of landscape evolution through digital topographic analysis of a set of purportedly relict landscapes on the southeastern margin of the Tibetan Plateau, one of the most geographically complex, climatically varied and biologically diverse regions of the world. We find that, in contrast to theory, the purported surfaces are not consistent with progressive establishment of a new, steeper, river grade, and therefore they cannot necessarily be interpreted as a remnant of an old, low relief surface. We propose an alternative model, supported by numerical experiments, in which tectonic deformation has disrupted the regional river network, leaving remnants of it isolated and starved of drainage area and thus unable to balance tectonic uplift. The implication is that the state of low relief with low erosion rate is developing in situ, rather than preserving past erosional conditions.

  8. A low power 2.5-5 GHz low-noise amplifier using 0.5-μm GaAs pHEMT technology

    International Nuclear Information System (INIS)

    A two-stage 2.5-5 GHz monolithic low-noise amplifier (LNA) has been fabricated using 0.5-μm enhanced mode AlGaAs/GaAs pHEMT technology. To achieve wide operation bandwidth and low noise figure, the proposed LNA uses a wideband matching network and a negative feedback technique. Measured results from 2.5 to 5 GHz demonstrate a minimum of 2.4-dB noise figure and 17-dB gain. The input and output return loss exceeded −10-dB across the band. The power consumption of this LNA is 33 mW. According to the author's knowledge, this is the lowest power consumption LNA fabricated in 0.5-μm AlGaAs/GaAs pHEMT with the comparable performance.

  9. A low power 2.5-5 GHz low-noise amplifier using 0.5-μm GaAs pHEMT technology

    Institute of Scientific and Technical Information of China (English)

    Peng Yangyang; Lu Kejie; Sui Wenquan

    2012-01-01

    A two-stage 2.5-5 GHz monolithic low-noise amplifier (LNA) has been fabricated using 0.5-μm enhanced mode AlGaAs/GaAs pHEMT technology.To achieve wide operation bandwidth and low noise figure,the proposed LNA uses a wideband matching network and a negative feedback technique.Measured results from 2.5 to 5 GHz demonstrate a minimum of 2.4-dB noise figure and 17-dB gain.The input and output return loss exceeded-10-dB across the band.The Power consumption of this LNA is 33 mW.According to the author's knowledge,this is the lowest power consumption LNA fabricated in 0.5-μm A1GaAs/GaAs pHEMT with the comparable performance.

  10. Extremely Low Density InAs Quantum Dots with No Wetting Layer

    Institute of Scientific and Technical Information of China (English)

    HUANG She-Song; NIU Zhi-Chuan; NI Hai-Qiao; ZHAN Feng; ZHAO Huan; SUN Zheng; XIA Jian-Bai

    2007-01-01

    Extremely low density inAs quantum dots (QDs) are grown by molecular beam droplet epitaxy.The gallium deposition amount is optimized to saturate exactly the excess arsenic atoms present on the GaAs substrate surface during growth,and low density InAs/GaAs QDs(4×106cm-2)are formed by depositing 0.65 monolayers(MLs)of indium.This is much less than the critical deposition thickness (1.7ML),which is necessary to form InAs/GaAs QDs with the conventional Stranski-Krastanov growth mode.The narrow photoluminescence linewidth of about 24 meV is insensitive to cryostat temperatures from 10 K to 250 K.All measurements indicate that there is no wetting layer connecting the QDs.

  11. Modulation of low-frequency oscillations in GaAs MESFETs' channel current by sidegating bias

    Institute of Scientific and Technical Information of China (English)

    DING Yong; LU Shengli; ZHAO Fuchuan

    2005-01-01

    Low-frequency oscillations in channel current are usually observed when measuring the GaAs MESFET's output characteristics. This paper studies the oscillations by testing the MESFET's output characteristics under different sidegate bias conditions. It is shown that the low-frequency oscillations of channel current are directly related to the sidegate bias. In other words, the sidegate bias can modulate the oscillations. Whether the sidegate bias varies positively or negatively, there will inevitably be a threshold voltage after which the low-frequency oscillations disappear. The observation is strongly dependent upon the peculiarities of channel-substrate (C-S) junction and impact ionization of traps-EL2 under high field. This conclusion is of particular pertinence to the design of low-noise GaAs IC's.

  12. Interpretation of thermal conductivity in LaFeAsO at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Lodhi, Pavitra Devi; Kaurav, Netram, E-mail: netramkaurav@yahoo.co.uk [Department of Physics, Govt. Holkar Science college, A. B. Road, Indore-452001 (India); Parchur, A. K. [Department of Biological Engineering, Utah State University, Logan, UT-84322 U.S.A (United States); Choudhary, K. K. [Department of Physics, National Defence Academy, Khadakwasla, Pune-411 0231 India (India)

    2015-06-24

    Thermal conductivity κ(T) of LaFeAsO is theoretically investigated below the spin density wave (SDW) anomaly. The lattice contribution to the thermal conductivity (κ{sub ph}) is discussed within the Debye-type relaxation rate approximation in terms of the acoustic phonon frequency and relaxation time below 150 K. The theory is formulated when heat transfer is limited by the scattering of phonons from defects, grain boundaries, charge carriers, and phonons. The lattice thermal conductivity dominates in LaFeAsO and is an artifact of strong phonon-impurity and -phonon scattering mechanism. Our result indicates that the maximum contribution comes from phonon scatters and various thermal scattering mechanisms provide a reasonable explanation for maximum appeared in κ (T)

  13. Low-cost copper complexes as p-dopants in solution processable hole transport layers

    International Nuclear Information System (INIS)

    We demonstrate the usage of the Lewis-acidic copper(II)hexafluoroacetylacetonate (Cu(hfac)2) and copper(II)trifluoroacetylacetonate (Cu(tfac)2) as low-cost p-dopants for conductivity enhancement of solution processable hole transport layers based on small molecules in organic light emitting diodes (OLEDs). The materials were clearly soluble in mixtures of environmentally friendly anisole and xylene and spin-coated under ambient atmosphere. Enhancements of two and four orders of magnitude, reaching 4.0 × 10−11 S/cm with a dopant concentration of only 2 mol% Cu(hfac)2 and 1.5 × 10−9 S/cm with 5 mol% Cu(tfac)2 in 2,2′,7,7′-tetra(N,N-ditolyl)amino-9,9-spiro-bifluorene (spiro-TTB), respectively, were achieved. Red light emitting diodes were fabricated with reduced driving voltages and enhanced current and power efficiencies (8.6 lm/W with Cu(hfac)2 and 5.6 lm/W with Cu(tfac)2) compared to the OLED with undoped spiro-TTB (3.9 lm/W). The OLED with Cu(hfac)2 doped spiro-TTB showed an over 8 times improved LT50 lifetime of 70 h at a starting luminance of 5000 cd/m2. The LT50 lifetime of the reference OLED with PEDOT:PSS was only 8 h. Both non-optimized OLEDs were operated at similar driving voltage and power efficiency

  14. Low-cost copper complexes as p-dopants in solution processable hole transport layers

    Energy Technology Data Exchange (ETDEWEB)

    Kellermann, Renate [Department for Materials Science and Engineering, Chair for Materials for Electronics and Energy Technology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen 91058 (Germany); Siemens AG – Corporate Technology, Guenther-Scharowsky-Str. 1, Erlangen 91058 (Germany); Taroata, Dan; Maltenberger, Anna; Hartmann, David; Schmid, Guenter [Siemens AG – Corporate Technology, Guenther-Scharowsky-Str. 1, Erlangen 91058 (Germany); Brabec, Christoph J. [Department for Materials Science and Engineering, Chair for Materials for Electronics and Energy Technology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen 91058 (Germany)

    2015-09-07

    We demonstrate the usage of the Lewis-acidic copper(II)hexafluoroacetylacetonate (Cu(hfac){sub 2}) and copper(II)trifluoroacetylacetonate (Cu(tfac){sub 2}) as low-cost p-dopants for conductivity enhancement of solution processable hole transport layers based on small molecules in organic light emitting diodes (OLEDs). The materials were clearly soluble in mixtures of environmentally friendly anisole and xylene and spin-coated under ambient atmosphere. Enhancements of two and four orders of magnitude, reaching 4.0 × 10{sup −11} S/cm with a dopant concentration of only 2 mol% Cu(hfac){sub 2} and 1.5 × 10{sup −9} S/cm with 5 mol% Cu(tfac){sub 2} in 2,2′,7,7′-tetra(N,N-ditolyl)amino-9,9-spiro-bifluorene (spiro-TTB), respectively, were achieved. Red light emitting diodes were fabricated with reduced driving voltages and enhanced current and power efficiencies (8.6 lm/W with Cu(hfac){sub 2} and 5.6 lm/W with Cu(tfac){sub 2}) compared to the OLED with undoped spiro-TTB (3.9 lm/W). The OLED with Cu(hfac){sub 2} doped spiro-TTB showed an over 8 times improved LT{sub 50} lifetime of 70 h at a starting luminance of 5000 cd/m{sup 2}. The LT{sub 50} lifetime of the reference OLED with PEDOT:PSS was only 8 h. Both non-optimized OLEDs were operated at similar driving voltage and power efficiency.

  15. Medical net cost of low alcohol consumption - a cause to reconsider improved health as the link between alcohol and wage?

    Directory of Open Access Journals (Sweden)

    Gerdtham Ulf G

    2009-10-01

    Full Text Available Abstract Background Studies have found a positive effect of low/moderate alcohol consumption on wages. This has often been explained by referring to epidemiological research showing that alcohol has protective effects on certain diseases, i.e., the health link is normally justified using selected epidemiological information. Few papers have tested this link between alcohol and health explicitly, including all diseases where alcohol has been shown to have either a protective or a detrimental effect. Aim Based on the full epidemiological information, we study the effect of low alcohol consumption on health, in order to determine if it is reasonable to explain the positive effect of low consumption on wages using the epidemiological literature. Methods We apply a non-econometrical cost-of-illness approach to calculate the medical care cost and episodes attributable to low alcohol consumption. Results Low alcohol consumption carries a net cost for medical care and there is a net benefit only for the oldest age group (80+. Low alcohol consumption also causes more episodes in medical care then what is saved, although inpatient care for women and older men show savings. Conclusion Using health as an explanation in the alcohol-wage literature appears invalid when applying the full epidemiological information instead of selected information.

  16. A piezoelectric spring-mass system as a low-frequency energy harvester.

    Science.gov (United States)

    Hu, Hongping; Hu, Lin; Yang, Jiashi; Wang, Hairen; Chen, Xuedong

    2013-04-01

    We propose a new structure consisting of a piezoelectric spring-mass system as a low-frequency piezoelectric energy harvester. A theoretical model is developed for the system from the theory of piezoelectricity. An analysis is performed to demonstrate the low-frequency nature of the system. Other basic characteristics of the energy harvester, including the output power, voltage, and efficiency, are also calculated and examined.

  17. Clinical examination findings as prognostic factors in low back pain: a systematic review of the literature

    OpenAIRE

    Hartvigsen, Lisbeth; Kongsted, Alice; Hestbaek, Lise

    2015-01-01

    Background There is a strong tradition of performing a clinical examination of low back pain (LBP) patients and this is generally recommended in guidelines. However, establishing a pathoanatomic diagnosis does not seem possible in most LBP patients and clinical tests may potentially be more relevant as prognostic factors. The aim of this review of the literature was to systematically assess the association between low-tech clinical tests commonly used in adult patients with acute, recurrent o...

  18. A piezoelectric spring-mass system as a low-frequency energy harvester.

    Science.gov (United States)

    Hu, Hongping; Hu, Lin; Yang, Jiashi; Wang, Hairen; Chen, Xuedong

    2013-04-01

    We propose a new structure consisting of a piezoelectric spring-mass system as a low-frequency piezoelectric energy harvester. A theoretical model is developed for the system from the theory of piezoelectricity. An analysis is performed to demonstrate the low-frequency nature of the system. Other basic characteristics of the energy harvester, including the output power, voltage, and efficiency, are also calculated and examined. PMID:23549545

  19. Carrier lifetime under low and high electric field conditions in semi-insulating GaAs

    International Nuclear Information System (INIS)

    The mobility lifetime product of holes and electrons under low electric field conditions was determined by alpha spectroscopy using SI-GaAs as a photo conductivity detector. The lifetime in high electric field (≥104 V/cm) of electrons was investigated with Schottky diodes. Both results were analyzed as a function of substrate resistivity and trap concentrations. We identified the ionized arsenic antisite defect (EL2+) as the dominant electron trap in the high field region and determined the capture cross-section as being (8.0±0.6) x 10-14 cm2. (orig.)

  20. High intensity low temperature (HILT) performance of space concentrator GaInP/GaInAs/Ge MJ SCs

    Energy Technology Data Exchange (ETDEWEB)

    Shvarts, Maxim Z., E-mail: shvarts@scell.ioffe.ru; Kalyuzhnyy, Nikolay A.; Mintairov, Sergey A.; Soluyanov, Andrei A.; Timoshina, Nailya Kh. [Ioffe Physical-Technical Institute, 26 Polytekhnicheskaya str., St.-Petersburg, 194021 (Russian Federation); Gudovskikh, Alexander S. [Saint-Petersburg Academic University - Nanotechnology Research and Education Centre RAS, St. Petersburg, 194021 (Russian Federation); Luque, Antonio [Ioffe Physical-Technical Institute, 26 Polytekhnicheskaya str., St.-Petersburg, 194021, Russia and Instituto de Energia Solar, Universidad Politecnica de Madrid, Madrid (Spain)

    2014-09-26

    In the work, the results of an investigation of GaInP/GaInAs/Ge MJ SCs intended for converting concentrated solar radiation, when operating at low temperatures (down to −190 °C) are presented. A kink of the cell I-V characteristic has been observed in the region close to V{sub oc} starting from −20°C at operation under concentrated sunlight. The causes for its occurrence have been analyzed and the reasons for formation of a built-in potential barrier for majority charge carriers at the n-GaInP/n-Ge isotype hetero-interface are discussed. The effect of charge carrier transport in n-GaInP/n-pGe heterostructures on MJ SC output characteristics at low temperatures has been studied including EL technique.

  1. Cryogenic Current Comparator as Low Intensity Beam Current Monitor in the CERN Antiproton Decelerators

    CERN Document Server

    Fernandes, M; Soby, L; Welsch, CP

    2013-01-01

    In the low-energy Antiproton Decelerator (AD) and the future Extra Low ENergy Antiproton (ELENA) rings at CERN, an absolute measurement of the beam intensity is essential to monitor any losses during the deceleration and cooling phases. However, existing DC current transformers can hardly reach the μA level, while at the AD and ELENA currents can be as low as 100 nA. A Cryogenic Current Comparator (CCC) based on a superconducting quantum interference device (SQUID) is currently being designed and shall be installed in the AD and ELENA machines. It should meet the following specifications: A current resolution smaller than 10 nA, a dynamic range covering currents between 100 nA and 1 mA, as well as a bandwidth from DC to 1 kHz. Different design options are being considered, including the use of low or high temperature superconductor materials, different CCC shapes and dimensions, different SQUID characteristics, as well as electromagnetic shielding requirements. In this contribution we present first results f...

  2. Multichannel Recorder for Low Frequency Signals: Application of Oscilloscope as Integrated Mobile Service for a Smartphone

    Directory of Open Access Journals (Sweden)

    Michal Kochlan

    2016-01-01

    Full Text Available Data acquisition and processing are well known for some time. Many applications use powerful hardware to acquire, process, and visualize signal waveforms. But there are some applications that do not have to perform high resolution signal acquisition and process large amount of data, for example, low frequency applications of embedded design and applications for remote power grid monitoring. The paper describes special system for low frequency signal data sample acquisition, processing, and visualization implemented as a service on Android-based smart device. The service makes smart device functioning as an oscilloscope or arbitrary waveform generator which is accessible remotely through Bluetooth. The design respects low power consumption requirements, simplicity, and user friendliness in application design. Application scenario was implemented as wireless data acquisition system for power grid monitoring.

  3. Utilization of peatlands as possible land resource for low-input agriculture: cultivation of Vaccinium species as an example

    Science.gov (United States)

    Tonutare, Tonu; Rodima, Ako; Rannik, Kaire; Shanskiy, Merrit

    2013-04-01

    The best way of soil protection is its sustainable and expedient use, which secures soils ecological functioning. Recent years, by exploitation of peat soils for their different use, has raised important issues concerning their input to global climate change as important source of greenhouse gases (GHG) emitters. The dynamics of GHG are determined by different factors as: site specific conditions including hydrology, soil type, vegetation, area management, including meteorological and climatic conditions. Therefore, in this current paper we are presenting the study results were we estimated CO2, CH4 and N2O emissions from exhausted cultivated peatland with Vaccinium species and determined the soil chemical composition. For comparision a virgin state peatland was observed. The main goals of the paper are: (1) to present the experimental results of greenhouse gases generation and peat chemical composition (antioxidant activity of peat, C/N ratio, fiber content, water extractable phenolics) relationships on different microsites either on natural plant cover or Vaccinium species cultivation area on exhausted milled peat area; (2) to discuss how peat soil quality contributes to greenhouse gases emission; (3) and what kind of relationship reveals between low input agricultural system in which Vaccinium species are cultivated on exhausted milled peat area. The study are is located in nearby Ilmatsalu (58°23'N, 26°31'E) in South Estonia, inside of which the three microsites are determined. Microsites are different from each other by exploitation and plant cover type. 1). Natural plant cover, 2). Cultivated area with Vaccinium angustifolium x V. corymbosum, 3). Cultivated area with Vaccinium angustifolium. The determined soil type according to WRB was Fibri Dystric Histosol. The main part of study focuses on the analyses of greenhouse gases. For this purpose the closed chamber method was used. The greenhouse gas samples were collected from spring to autumn 2011 throughout

  4. Development of a piston utilizing carbon-cluster as a pressure transmission medium at low temperature

    International Nuclear Information System (INIS)

    It is necessary to require pressure transmission mechanism in the vacuum and low temperature environment such mechanically RF tuning operation for superconducting RF cavities. As a medium of pressure transmission, water, oil and air can not use such environment. Nano-cluster particles and carbon seems to have possibility of pressure transmission medium. Because their characteristics of chemical and physical reaction at low temperature environment is very stable. Also they have small number of the friction coefficient. We have been studying possibility of their characteristics as pressure transmission medium. (author)

  5. Risks of low-LET radiation as given in BEIR-III and previous reports

    International Nuclear Information System (INIS)

    This report presents the conclusions of a review of the report ΣThe Effects on Populations of Exposure to Low Levels of Ionizing RadiationΣ, BEIR-III, published by the U.S. National Academy of Sciences in 1980 and other related reports. The committee concludes that, in as far as the estimates of risk from low-LET radiation are concerned, the BEIR-III report does not provide any new data that might suggest that the present dose limits promulgated by the AECB should be changed

  6. Studies on electrical double layer capacitor with a low-viscosity ionic liquid 1-ethyl-3-methylimidazolium tetracyanoborate as electrolyte

    Indian Academy of Sciences (India)

    G P Pandey; S A Hashmi

    2013-08-01

    The performance of an electrical double layer capacitor (EDLC) composed of high surface area activated carbon electrodes and a new ionic liquid, 1-ethyl-3-methylimidazolium tetracyanoborate, [EMIm]TCB, as the electrolyte has been investigated by impedance spectroscopy, cyclic voltammetry and galvanostatic charge–discharge studies. The high ionic conductivity (∼1.3 × 10-2 S cm-1 at 20 °C) and low viscosity (∼22 cP) of the ionic liquid, [EMIm]TCB, make it attractive as electrolyte for its use in EDLCs. The optimum capacitance value of 195.5 F g-1 of activated carbon has been achieved with stable cyclic performance.

  7. The low-methionine content of vegan diets may make methionine restriction feasible as a life extension strategy.

    Science.gov (United States)

    McCarty, Mark F; Barroso-Aranda, Jorge; Contreras, Francisco

    2009-02-01

    Recent studies confirm that dietary methionine restriction increases both mean and maximal lifespan in rats and mice, achieving "aging retardant" effects very similar to those of caloric restriction, including a suppression of mitochondrial superoxide generation. Although voluntary caloric restriction is never likely to gain much popularity as a pro-longevity strategy for humans, it may be more feasible to achieve moderate methionine restriction, in light of the fact that vegan diets tend to be relatively low in this amino acid. Plant proteins - especially those derived from legumes or nuts - tend to be lower in methionine than animal proteins. Furthermore, the total protein content of vegan diets, as a function of calorie content, tends to be lower than that of omnivore diets, and plant protein has somewhat lower bioavailability than animal protein. Whole-food vegan diets that moderate bean and soy intake, while including ample amounts of fruit and wine or beer, can be quite low in methionine, while supplying abundant nutrition for health (assuming concurrent B12 supplementation). Furthermore, low-fat vegan diets, coupled with exercise training, can be expected to promote longevity by decreasing systemic levels of insulin and free IGF-I; the latter effect would be amplified by methionine restriction - though it is not clear whether IGF-I down-regulation is the sole basis for the impact of low-methionine diets on longevity in rodents.

  8. Formation process and superparamagnetic properties of (Mn,Ga)As nanocrystals in GaAs fabricated by annealing of (Ga,Mn)As layers with low Mn content

    DEFF Research Database (Denmark)

    Sadowski, Janusz; Domagala, Jaroslaw Z.; Mathieu, Roland;

    2011-01-01

    X-ray diffraction, transmission electron microscopy, and magnetization measurements are employed to study the structural and magnetic properties of Mn-rich (Mn,Ga)As nanocrystals embedded in GaAs. These nanocomposites are obtained by moderate-temperature (400°C) and high-temperature (560°C and 63......, as well as for the absence of spin-glass dynamics. These findings point to weak coupling between nanocrystals even in layers with the highest nanocrystal density....

  9. Suppression of low-frequency charge noise in gates-defined GaAs quantum dots

    International Nuclear Information System (INIS)

    To reduce the charge noise of a modulation-doped GaAs/AlGaAs quantum dot, we have fabricated shallow-etched GaAs/AlGaAs quantum dots using the wet-etching method to study the effects of two-dimensional electron gas (2DEG) underneath the metallic gates. The low-frequency 1/f noise in the Coulomb blockade region of the shallow-etched quantum dot is compared with a non-etched quantum dot on the same wafer. The average values of the gate noise are approximately 0.5 μeV in the shallow-etched quantum dot and 3 μeV in the regular quantum dot. Our results show the quantum dot low-frequency charge noise can be suppressed by the removal of the 2DEG underneath the metallic gates, which provides an architecture for noise reduction

  10. Suppression of low-frequency charge noise in gates-defined GaAs quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    You, Jie; Li, Hai-Ou, E-mail: haiouli@ustc.edu.cn, E-mail: gpguo@ustc.edu.cn; Wang, Ke; Cao, Gang; Song, Xiang-Xiang; Xiao, Ming; Guo, Guo-Ping, E-mail: haiouli@ustc.edu.cn, E-mail: gpguo@ustc.edu.cn [Key Laboratory of Quantum Information, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2015-12-07

    To reduce the charge noise of a modulation-doped GaAs/AlGaAs quantum dot, we have fabricated shallow-etched GaAs/AlGaAs quantum dots using the wet-etching method to study the effects of two-dimensional electron gas (2DEG) underneath the metallic gates. The low-frequency 1/f noise in the Coulomb blockade region of the shallow-etched quantum dot is compared with a non-etched quantum dot on the same wafer. The average values of the gate noise are approximately 0.5 μeV in the shallow-etched quantum dot and 3 μeV in the regular quantum dot. Our results show the quantum dot low-frequency charge noise can be suppressed by the removal of the 2DEG underneath the metallic gates, which provides an architecture for noise reduction.

  11. Low temperature processed planar heterojunction perovskite solar cells employing silver nanowires as top electrode

    Science.gov (United States)

    Zhang, Jianhua; Li, Fushan; Yang, Kaiyu; Veeramalai, Chandrasekar Perumal; Guo, Tailiang

    2016-04-01

    In this paper, we reported a low temperature processed planar heterojunction perovskite solar cell employing silver nanowires as the top electrode and ZnO nanoparticles as the electron transport layer. The CH3NH3PbI3 perovskite was grown as the light absorber via two-step spin-coating technique. The as-fabricated perovskite solar cell exhibited the highest power conversion efficiency of 9.21% with short circuit current density of 19.75 mA cm-2, open circuit voltage of 1.02, and fill factor value of 0.457. The solar cell's performance showed negligible difference between the forward and reverse bias scan. This work paves a way for realizing low cost solution processable solar cells.

  12. Choked Jets and Low-Luminosity Gamma-Ray Bursts as Hidden Neutrino Sources

    CERN Document Server

    Senno, Nicholas; Meszaros, Peter

    2015-01-01

    We consider choked gamma-ray burst (GRB) jets as possible sources of high-energy cosmic neutrinos. We take into account the jet propagation physics and radiation constraints, which are relevant for high-energy neutrino production in dense environments. Efficient shock acceleration of cosmic rays inside a high density stellar environment is possible for sufficiently low-power jets and/or jets buried in an extended envelope, and such conditions are favorable also for the GRB jets to become stalled. Such choked jets may explain transrelativistic SNe and low-luminosity (LL) GRBs. Focusing on this possibility, we calculate the resulting neutrino spectra including the relevant microphysical processes such as multipion production in pp and pgamma interactions, as well as the energy losses of mesons and muons. We obtain diffuse neutrino spectra using the latest results on the luminosity function of LL GRBs. Although current uncertainties are large, we confirm that LL GRBs can potentially give a significant contributi...

  13. Low Bandgap InAs-Based Thermophotovoltaic Cells for Heat-Electricity Conversion

    Science.gov (United States)

    Krier, A.; Yin, M.; Marshall, A. R. J.; Krier, S. E.

    2016-06-01

    The practical realization of thermophotovoltaic (TPV) cells, which can directly convert heat into electric power, is of considerable technological interest. However, most existing TPV cells require heat sources at temperatures of ˜1800°C. Here we report a low bandgap mid-infrared cell based on InAs and demonstrate TPV operation with heat sources at temperatures in the range 500-950°C. The maximum open circuit voltage ( V oc) and short circuit current density ( J sc) were measured as 0.06 V and 0.89 A cm-2 for a blackbody temperature of 950°C and an incident power density of 720 mW cm-2 without antireflection coating or electrode optimisation. TPV operation was obtained with heat sources at temperatures as low as 500°C, which represents progress towards energy scavenging and waste heat recovery applications.

  14. Pigs as animal model for low-birth-weight babies. Developing cognitive tests and examining neuroprotection

    NARCIS (Netherlands)

    Gieling, E.T.

    2013-01-01

    In this thesis the cognitive performance of piglets with low birth weight (LBW) caused by intra-uterine growth restriction (IUGR), and the effects of a possible therapy to prevent IUGR-related brain damage and associated cognitive impairments were studied. To achieve these goals, several conditions

  15. Social and Musical Objectives or Experiences School Music Teachers Anticipate Their Students Will Achieve as a Result of Attending a Summer Music Camp

    Science.gov (United States)

    Richards, Eric W.

    2011-01-01

    The purpose of this study was to investigate specific social and musical objectives or experiences school music teachers anticipate their students will achieve as a result of attending a summer music camp. A survey instrument was developed to collect demographic data and responses to questions regarding 14 specific musical and social variables.…

  16. Relative Effectiveness of Two Approaches to the Teaching of Music Theory on the Achievement and Attitudes of Undergraduate Students Training as Church Musicians

    Science.gov (United States)

    Kinchen, John Dawson, III

    2012-01-01

    As a result of a perceived need to improve the music theory curricula for the preparation of church music leaders, this study compared two diverse approaches to the teaching of music theory for church music university students on achievement, attitudes, and self-preparedness. This current study was a quantitative, quasi-experimental research…

  17. Yoga as a treatment for chronic low back pain: A systematic review of the literature

    OpenAIRE

    Chang, Douglas G.; Holt, Jacquelyn A.; Sklar, Marisa; Groessl, Erik J.

    2016-01-01

    Objectives Chronic low back pain (CLBP) affects millions of people worldwide, and appears to be increasing in prevalence. It is associated not only with pain, but also with increased disability, psychological symptoms, and reduced quality of life. There are various treatment options for CLBP, but no single therapy stands out as being the most effective. In the past 10 years, yoga interventions have been studied as a CLBP treatment approach. The objective of this paper is to review the current...

  18. MOSFET with a boron-loaded gate as a low-energy neutron dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Gavelle, M. [CNRS, LAAS, 7 avenue du colonel Roche, F-31077 Toulouse Cedex 4 (France); Universite de Toulouse, UPS, INSA, INP, ISAE, LAAS, F-31077 Toulouse (France); Sarrabayrouse, G., E-mail: sarra@laas.fr [CNRS, LAAS, 7 avenue du colonel Roche, F-31077 Toulouse Cedex 4 (France); Universite de Toulouse, UPS, INSA, INP, ISAE, LAAS, F-31077 Toulouse (France); Scheid, E. [CNRS, LAAS, 7 avenue du colonel Roche, F-31077 Toulouse Cedex 4 (France); Universite de Toulouse, UPS, INSA, INP, ISAE, LAAS, F-31077 Toulouse (France); Siskos, S.; Fragopoulou, M.; Zamani, M. [Aristotle University of Thessaloniki, Physics Department, 54124 Thessaloniki (Greece)

    2011-12-15

    A MOSFET-based low-energy neutron dosimeter has been fabricated using a {sup 10}B loaded gate electrode as (n,{alpha}) converter. The response to thermal neutrons has been studied. - Highlights: > Feasibility of a metal-oxide-semiconductor thermal neutron dosimeter is investigated. > Monolithically integrated boron-loaded gate electrode acts as a (n,{alpha}) converter. > Sensitivity of 2 V/Sv is obtained.

  19. Low band gap polymeric solar cells using solution-processable copper iodide as hole transporting layer

    Science.gov (United States)

    Chaudhary, Neeraj; Kesari, J. P.; Chaudhary, Rajiv; Patra, Asit

    2016-08-01

    In the present work, we have shown the performance of solution-processable copper iodide (CuI) as an alternative hole transporting layer (HTL) for polymeric solar cells. Optical spectra of the CuI thin film reveal highly transparent and practically no absorption in the range vis-NIR region (450-1110 nm). X-ray diffraction (XRD) patterns of CuI exhibits as a p-type semiconductor as well as crystalline nature. The photovoltaic devices were fabricated using PCDTBT and PTB7 as donor materials blended with PC71BM as an acceptor material. The power conversion efficiencies (PCEs) based on CuI as an HTL have been achieved to up to 3.04% and 4.48% for PCDTBT and PTB7 based donor materials respectively with a configuration based on ITO/CuI(40 nm)/active layer (60 nm)/Al (120 nm). This study clearly indicated that the devices made with CuI as an HTL showed superior performance than the device fabricated from PEDOT:PSS layer as an HTL. Morphological characterization of the HTL using scanning electron microscopy (SEM) and atomic force microscope (AFM) were carried for better understanding.

  20. Passivhaus as a low-energy building standard. Contribution to a typology

    Energy Technology Data Exchange (ETDEWEB)

    Dequaire, X. [Oslo and Akershus University College of Applied Sciences, Pboks 4, St. Olavs plass, 0130 Oslo (Norway)

    2012-08-15

    With a rising concern for climate change, energy security and the environment, passive houses are receiving increasing interest among politicians and planners, and the concept is used and expressed in several settings to describe a type of very-low-energy building. Different approaches have arisen with several attempts to provide systems of validation of low-energy buildings. One major reference is the formalization into the German Passivhaus standard by the Passivhaus Institut in Darmstadt, which is presented as a strategy for energy efficiency. This article explores several underlying key issues, and a typology for energy in buildings is proposed and then developed for passive houses and exemplified using the Passivhaus standard. The concepts of low-energy buildings as expressed in some European standards, labels or certificates are explained and a special attention is provided to the Passivhaus standard. The final analysis shows the weakness of some approaches and the pertinence of the Passivhaus standard and invites for further research.

  1. Thin-film ZnO as micromechanical actuator at low frequencies

    NARCIS (Netherlands)

    Blom, F.R.; IJntema, D.J.; Pol, van de F.C.M.; Elwenspoek, M.; Fluitman, J.H.J.; Popma, Th.J.A.

    1990-01-01

    A new model is proposed for the low-frequency piezoelectric activity of ZnO films grown on CVD SiO2. In this MOS structure, with ZnO as the semiconductor, a depletion layer is induced by means of a d.c. bias voltage. Using standard semiconductor theory, an expression is derived relating the electric

  2. Weekly low-dose mitoxantrone plus doxorubicin as second-line chemotherapy for advanced breast cancer

    NARCIS (Netherlands)

    M. Bontenbal (Marijke); A.S.Th. Planting (André); C.J. Rodenburg (C.); A. Dees; J. Verweij (Jaap); C.C.M. Bartels (Carina); J. Alexieva-Figusch (Jana); W.L.J. van Putten (Wim); J.G.M. Klijn (Jan)

    1992-01-01

    textabstractWeekly low dose mitoxantrone (3 mg/m2) plus doxorubicin (8 mg/m2) was administered as second-line chemotherapy to 33 patients with advanced breast cancer. Four out of 28 evaluable patients (14%) obtained a partial response with a median duration of 34 weeks (range 18-67+ weeks), while 8

  3. Low temperature transport in p-doped InAs nanowires

    DEFF Research Database (Denmark)

    Upadhyay, Shivendra; Jespersen, Thomas Sand; Madsen, Morten Hannibal;

    2013-01-01

    We present low temperature electrical measurements of p-type Indium Arsenide nanowires grown via molecular beam epitaxy using Beryllium as a dopant. Growth of p-type wires without stacking faults is demonstrated. Devices in field-effect geometries exhibit ambipolar behavior, and the temperature...

  4. Renewable and low-carbon energies as mitigation options of climate change for China

    NARCIS (Netherlands)

    Urban, F.; Benders, R. M. J.; Moll, H. C.

    2009-01-01

    This article discusses how renewable and low-carbon energies can serve as mitigation options of climate change in China's power sector. Our study is based on scenarios developed in PowerPlan, a bottom-up model simulating a countries' power sector and its emissions. We first adjusted the model to Chi

  5. Energy based study of quasi-static delamination as a low cycle fatigue process

    NARCIS (Netherlands)

    Amaral, L.; Yao, L.; Alderliesten, R.C.; Benedictus, R.

    2015-01-01

    This work proposes to treat quasi-static mode I delamination growth of CFRP as a low-cycle fatigue process. To this end, mode I quasi-static and fatigue delamination tests were performed. An average physical Strain Energy Release Rate (SERR), derived from an energy balance, is used to characterize t

  6. Low-cost hydrophobic layer as a top plate in two-plate digital microfluidics

    Science.gov (United States)

    Tabatabaeipour, Ghiasadin; Hajghassem, Hassan; MohtashamiFar, Mansoor

    2015-07-01

    Digital microfluidics is an emerging technology that is able to manipulate droplets individually. To develop this technology it is needed to use cheaper and more accessible materials for its fabrication. At present, materials commonly used for the hydrophobic layer in these devices are expensive materials that require a legal agreement. In this paper, polydimethylsiloxane (PDMS), which is a common and cheap material in the field of microfluidic, is used as a hydrophobic material for both top and bottom plates of digital microfluidic devices. The droplet cannot be actuated using DC voltage in a surrounding air environment. The reason for the droplet pinning is the high contact angle hysteresis of PDMS surface and considerable thickness of hydrophobic layer on the top plate. In order to overcome this problem, we have exploited a suitable AC voltage (230 Vrms and 8 kHz) as well as changing the surrounding environment to the olive oil. Therefore this paper demonstrates the feasibility of using PDMS as a hydrophobic layer in two-plate digital microfluidics.

  7. An arctic low-energy house as experimental setup for studies of heat dynamics of buildings

    DEFF Research Database (Denmark)

    Andersen, Philip Hvidthøft Delff; Rode, Carsten; Madsen, Henrik

    2013-01-01

    This paper addresses the difficulties in pinpointing reasons for unexpectedly high energy consumption in construction, and in low-energy houses especially. Statistical methods are applied to improve the insight into the energy performance and heat dynamics of a building based on consumption records...... and weather data. Dynamical methods separate influences from outdoor temperature, solar radiation, and wind on the energy consumption in the building. The studied building is a low-energy house in Sisimiut, Greenland. Weather conditions like large temperature differences between indoors and outdoors...... throughout long winters, strong winds, and very different circumstances regarding solar radiation compared to areas where low-energy houses are usually built, make the location very interesting for modeling and testing purposes. In 2011 new measurement equipment was installed in the house, which will be used...

  8. Lattice sites and damage annealing of Er in low-dose implanted GaAs

    CERN Document Server

    Wahl, U; Langouche, G

    1999-01-01

    We have used conversion electron emission channeling to determine the lattice location of $^{167m}$Er ($t_{1/2}$=2.28 s) in GaAs after 60 keV room temperature implantation of $^{167}$Tm ($t_{1/2}$=9.25 d) at low doses (0.6-3 $\\times 10^{13}$ cm$^{-2}$). Following a recovery step of the implantation damage at 200-300°C, we observe a large fraction of Er (45-68%) on substitutional Ga sites. A second fraction of Er is found on the T$_{As}$ sites (the tetrahedral interstitial sites with nearest As neighbours). The fraction on T$_{As}$ sites reaches a maximum of 12-23% following annealing at 500-600°C. At higher annealing temperatures the channeling effects decrease markedly, which we attribute to the well-known degradation of GaAs due to As evaporation.

  9. Low Blood Lead Levels and educational achievement in 7-8 year old children in the Community of Madrid (Spain Bajos niveles de plomo en sangre y rendimiento escolar en niños de 7-8 años en la Comunidad de Madrid (España Baixos níveis de chumbo no sangue e sucesso escolar nas crianças entre os 7-8 anos na Comunidade de Madrid (Espanha

    Directory of Open Access Journals (Sweden)

    María José Martínez García

    2013-06-01

    Full Text Available Background: Lead affects the behavioral and cognitive functions of children. The current lead safety level for avoiding these adverse effects is still controversial.Methods of study: A cross-sectional study included 511 children from 23 primary schools within the Comunidad de Madrid (the Madrid Region –including the city of Madrid and the large urban-industrial conurbation of satellite towns surrounding it, Spain. The children’s blood lead levels were determined by atomic absorption spectrophotometry. In addition, the teachers completed an eight-item questionnaire about the children’s behavior and academic achievement. Parents filled in a self-completion survey about the sociodemographic variables of the children and the family.Results: The mean Blood Lead Level (BLL of the children was 4.1 μg/dL SD 1.6 μg/dL (log transformed 3.8 μg/dL SD 0.2 μg/dL. Multivariate analysis controlling for relevant sociodemographic cofactors (among others, sex, age and educational level of the parents showed a negative association, but this was not statistically significant.Conclusions: Despite the low blood lead levels found in the children of the Comunidad de Madrid (Spain and the design limitations of the study, the results obtained suggest the existence of a harmful, but not statistically significant, effect of blood lead on the behavior and academic achievement of children.Objetivos: El plomo en sangre provoca en los niños efectos sobre las funciones cognitivas y sobre el comportamiento. No existe acuerdo sobre los niveles en sangre que evitarían esos efectos.Métodos: Estudio transversal en el que participaron 511 niños pertenecientes a 23 colegios de la Comunidad de Madrid (la ciudad de Madrid y su Corona Metropolitana, España, a los que se les determinaron los niveles de plomo en sangre por espectrofotometría de absorción atómica. Además, los profesores cumplimentaron un cuestionario de ocho preguntas sobre aspectos conductuales y de

  10. Preparation and Evaluation of Jojoba Oil Methyl Ester as Biodiesel and as Blend Components in Ultra Low Sulfur Diesel Fuel

    Science.gov (United States)

    The jojoba plant (Simmondsia chinensis L.) produces seeds that contain around 50 to 60 weight percent of inedible long-chain wax esters that are suitable as a potential feedstock for biodiesel production. A Jojoba oil methyl ester (JME) was prepared in effort to evaluate an important fuel propertie...

  11. Omnidirectional reflector using nanoporous SiO2 as a low-refractive-index material.

    Science.gov (United States)

    Xi, J Q; Ojha, Manas; Cho, Woojin; Plawsky, J L; Gill, W N; Gessmann, Th; Schubert, E F

    2005-06-15

    Triple-layer omnidirectional reflectors (ODRs) consisting of a semiconductor, a quarter-wavelength transparent dielectric layer, and a metal have high reflectivities for all angles of incidence. Internal ODRs (ambient material's refractive index n > 1.0) are demonstrated that incorporate nanoporous SiO2, a low-refractive-index material (n = 1.23), as well as dense SiO2 (n = 1.46). GaP and Ag serve as the semiconductor and the metal layer, respectively. Reflectivity measurements, including angular dependence, are presented. Calculated angle-integrated TE and TM reflectivities for ODRs employing nanoporous SiO2 are R(int)/TE = 99.9% and R(int)/TM = 98.9%, respectively, indicating the high potential of the ODRs for low-loss waveguide structures.

  12. Low Cost Al-Si Casting Alloy As In-Situ Composite for High Temperature Applications

    Science.gov (United States)

    Lee, Jonathan A.

    2000-01-01

    A new aluminum-silicon (Al-Si) alloy has been successfully developed at NASA- Marshall Space Flight Center (MSFC) that has significant improvement in tensile and fatigue strength at elevated temperatures (500 F-700 F). The alloy offers a number of benefits such as light weight, high hardness, low thermal expansion and high surface wear resistance. In hypereutectic form, this alloy is considered as an in-situ Al-Si composite with tensile strength of about 90% higher than the auto industry 390 alloy at 600 F. This composite is very economically produced by using either conventional permanent steel molds or die casting. The projected material cost is less than $0.90 per pound, and automotive components such as pistons can be cast for high production rate using conventional casting techniques with a low and fully accounted cost. Key Words: Metal matrix composites, In-situ composite, aluminum-silicon alloy, hypereutectic alloy, permanent mold casting, die casting.

  13. FLUOROETHERS AS A WORKING FLUIDS FOR LOW TEMPERATURE ORGANIC RANKINE CYCLE

    Directory of Open Access Journals (Sweden)

    Artemenko S.V

    2014-12-01

    Full Text Available Hydrofluoroethers as a new class of working fluids for the organic Rankine cycle have been considered to utilize the low-potential waste heat. Temperature range 300…400 K was chosen to provide energy conversion of waste heat from fuel cells. The direct assessment of the efficiency criteria for the Rankine cycle via artificial neural networks (ANN was used. To create ANN the critical parameters of substance and normal boiling temperature as input were chosen. The forecast of efficiency criteria for the Rankine cycle as output parameter which reproduces the coefficient of performance with high accuracy and without thermodynamic property calculations was presented.

  14. Reading and Math Achievement among Low-Income Urban Latino Youth: The Role of Immigration

    Science.gov (United States)

    Guttmannova, Katarina

    2016-01-01

    Using data from a household-based, stratified random sample of youth and their caregivers from low-income inner-city neighborhoods, this study examined the variability in the academic achievement of Latino youth. The results indicate a significant advantage in reading achievement for first- and second-generation immigrant youth, as compared to the…

  15. rganizational features as situational strength: engaging the low-conscientious employee

    Directory of Open Access Journals (Sweden)

    Milam, A.

    2015-07-01

    Full Text Available One of the most robust findings in work psychology is the role that conscientiousness plays in performance; more recently, research indicates that conscientious employees are also the most engaged in their work. The present study examines whether the organization has any role in this relation, and if it is possible for individuals who are low in conscientiousness to also feel high levels of engagement. One hundred forty-one full-time Romanian workers and their peers, representing a variety of industries, were surveyed, revealing that features of the organization can actually attenuate the relation between conscientiousness and engagement. Specifically, when employees perceive that the organization is relatively formalized (i.e., where following rules is important, and in organizations where there is a perception that effort is rewarded, conscientiousness is not as strongly associated with engagement. These organizational features represent situational strength, and when situations are strong, scripts and rules tend to predict behavior, rather than personality. As such, it may be possible for low-conscientiousness individuals to actually become more engaged through organizational change. For those who are low in conscientiousness, for example, a formal work environment likely provides structure and decreases ambiguity, which aids in lower conscientious employees becoming more engaged. Similarly, when it is perceived that the organization rewards effort, those who are low in conscientiousness receive this reinforcement, and likely benefit the most, as their levels of engagement tend to approach those who are higher in conscientiousness.

  16. The effects of low level laser therapy (Ga- Al- As on myofascial pain dysfunction syndrome

    Directory of Open Access Journals (Sweden)

    Sahebjamei M

    2002-06-01

    Full Text Available Muscular pain is one of the most common causes for facial pain. Myofacial pain dysfunction"nsyndrome (MPDS is one of the most important disorders of facial area that affected patients suffer from"npain, tenderness of one or more masticatory muscles and limitation of movements. Lack of specific and"neffective therapeutic method, makes it necessary to find a treatment to decrease pain. Considering the"nanalgesic and anti- inflammatory effects of low-level laser, some investigators have recommended it for"nMPDS patient's treatment. In this study, the effects of low level laser (Ga-Al-As on MPDS patients"nreferred to dental faculty of Tehran University of Medical Sciences, were investigated. Twenty- two"nMPDS patents, with mean age 33.32 years, were treated for 4 weeks (12 visits. Clinical examinations"nwere performed in 6 stages. The results of this study showed that variables such as pain severity, cheek"npain, pain frequency and tenderness of masseter, temporal, internal and external pterygoid muscles, had a"nstatistically significant improvement at the end of treatment with low level laser (GA-A1-AS which"nlasted for three months, (follow- up period. Results of this study showed that, low-level laser therapy"nhas a sedative effect on the pain and tenderness of masticatory muscles in MPDS. Patients and having an"naccurate and regular program to complete treatment period, has an important role in MPDS"nimprovement.

  17. Conformations of 1-heptene secondary ozonide as studied by low temperature FT-IR spectroscopy

    Science.gov (United States)

    Bariseviciute, R.; Ceponkus, J.; Sablinskas, V.; Kimtys, L.

    2007-11-01

    Conformational diversity of the 1-heptene secondary ozonides (SOZ) in solid neat films as well as isolated in Ar or CO 2 matrices was studied by the means of FT-IR absorption spectroscopy. The ozonization reaction was performed at 77 K in the neat films of the reactants. The spectra of the ozonide were analyzed by combining the experimental data with the results of theoretical calculations performed at B3LYP 6-311++G (3df, 3pd) level. It was found that the samples of 1-heptene secondary ozonide exist as a mixture of three dominating conformers. The most stable conformer is the one with O-O half-chair configuration of the five membered ring, the aliphatic radical attached to the ring in equatorial position and the aliphatic chain being in gauche (∠OCCC ≈ -60°) position. The other two stable conformers are equatorial with aliphatic chain in anti (∠OCCC ≈ 180°) and gauche (∠OCCC ≈ 60°) positions. It was found from Van't Hoff plots that Δ H of the equatorial anti conformer is equal to 0.24 ± 0.03 kJ/mol. The experimental value of Δ H is in reasonable accordance to the calculated one - 0.5 kJ/mol.

  18. Scientific Reasoning, School Achievement and Gender: A Multilevel Study of between and within School Effects in Finland

    Science.gov (United States)

    Thuneberg, Helena; Hautamäki, Jarkko; Hotulainen, Risto

    2015-01-01

    The relationships between reasoning and school achievement were studied taking into account the multilevel nature (school- and class-levels) of the data. We gathered data from 51 classes at seven schools in metropolitan and Eastern Finland (N = 769, 395 males, 15-year-old students). To study scientific reasoning, we used a modified version of…

  19. A thin-film cryotron suitable for use as an ultra-low-temperature switch

    Science.gov (United States)

    Lowell, Peter J.; Mates, John A. B.; Doriese, W. Bertrand; Hilton, Gene C.; Morgan, Kelsey M.; Swetz, Daniel S.; Ullom, Joel N.; Schmidt, Daniel R.

    2016-10-01

    Low-temperature superconducting circuits have become important for many scientific applications. However, there are presently no high current-capacity switches (˜1 mA) with low power dissipation for sub-Kelvin operation. One candidate for a sub-Kelvin switch is the cryotron, a device in which the superconductivity of a wire is suppressed with a magnetic field. Here, we demonstrate a cryotron switch suitable for sub-Kelvin temperatures. In the closed state, the maximum device current is about 900 μA. The device is switched to its open state with 2 mA of control current and has a leakage of approximately 500 nA. The transition between the closed and open states of the device is faster than 200 ns, where the measurement is limited by the speed of our measurement apparatus. We also discuss low-temperature applications for our cryotron such as a single-pole, double-throw switch.

  20. A low noise low power 512×256 ROIC for extended wavelength InGaAs FPA

    Science.gov (United States)

    Huang, Songlei; Huang, Zhangcheng; Chen, Yu; Li, Tao; Fang, Jiaxiong

    2015-05-01

    A low noise low power 512×256 readout integrated circuit (ROIC) based on Capacitance Trans-impedance Amplifier (CTIA) was designed in this paper. The ROIC with 30μm pixel-pitch and 70 fF integrated capacitance as normal structure and test structure capacitance from 5 to 60 fF, was fabricated in 0.5μm DPTM CMOS process. The results showed that output voltage was larger than 2.0V and power consumption was about 150mW, output ROIC noise was about 3.6E-4V which equivalent noise was 160e-, and the test structure noise was from 20e- to 140 e-. Compared the readout noises in Integration Then Readout (ITR) mode and Integration While Readout (IWR) mode, it indicated that in IWR mode, readout noise comes mainly from both integration capacitance and sampling capacitance, while in ITR mode, readout noise comes mostly from sampling capacitance. Finally the ROIC was flip-chip bonded with Indium bumps to extended wavelength InGaAs detectors with cutoff wavelength 2.5μm at 200K. The peak detectivity exceeded 5E11cmHz1/2/w with 70nA/cm2 dark current density at 200K.

  1. Microbial fuel cells as power supply of a low-power temperature sensor

    Science.gov (United States)

    Khaled, Firas; Ondel, Olivier; Allard, Bruno

    2016-02-01

    Microbial fuel cells (MFCs) show great promise as a concomitant process for water treatment and as renewable energy sources for environmental sensors. The small energy produced by MFCs and the low output voltage limit the applications of MFCs. Specific converter topologies are required to step-up the output voltage of a MFC. A Power Management Unit (PMU) is proposed for operation at low input voltage and at very low power in a completely autonomous way to capture energy from MFCs with the highest possible efficiency. The application of sensors for monitoring systems in remote locations is an important approach. MFCs could be an alternative energy source in this case. Powering a sensor with MFCs may prove the fact that wastewater may be partly turned into renewable energy for realistic applications. The Power Management Unit is demonstrated for 3.6 V output voltage at 1 mW continuous power, based on a low-cost 0.7-L MFC. A temperature sensor may operate continuously on 2-MFCs in continuous flow mode. A flyback converter under discontinuous conduction mode is also tested to power the sensor. One continuously fed MFC was able to efficiently and continuously power the sensor.

  2. Exercise as a Mean to Control Low-Grade Systemic Inflammation

    Directory of Open Access Journals (Sweden)

    Neha Mathur

    2008-01-01

    Full Text Available Chronic noncommunicable diseases (CNCDs, which include cardiovascular disease, some cancers, for example, colon cancer, breast cancer, and type 2 diabetes, are reaching epidemic proportions worldwide. It has now become clear that low-grade chronic inflammation is a key player in the pathogenesis of most CNCDs. Given that regular exercise offers protection against all causes of mortality, primarily by protection against atherosclerosis and insulin resistance, we suggest that exercise may exert some of its beneficial health effects by inducing anti-inflammatory actions. Recently, IL-6 was introduced as the first myokine, defined as a cytokine, which is produced and released by contracting skeletal muscle fibres, exerting its effects in other organs of the body. We suggest that skeletal muscle is an endocrine organ and that myokines may be involved in mediating the beneficial effects against CNCDs associated with low-grade inflammation.

  3. The shape and structure of cometary nuclei as a result of low-velocity accretion

    Science.gov (United States)

    Jutzi, M.; Asphaug, E.

    2015-06-01

    Cometary nuclei imaged from flyby and rendezvous spacecraft show common evidence of layered structures and bilobed shapes. But how and when these features formed is much debated, with distinct implications for solar system formation, dynamics, and geology. We show that these features could be a direct result of accretionary collisions, based on three-dimensional impact simulations using realistic constitutive properties. We identify two regimes of interest: layer-forming splats and mergers resulting in bilobed shapes. For bodies with low tensile strength, our results can explain key morphologies of cometary nuclei, as well as their low bulk densities. This advances the hypothesis that nuclei formed by collisional coagulation—either out of cometesimals accreting in the early solar system or, alternatively, out of comparable-sized debris clumps paired in the aftermath of major collisions.

  4. Reasons Low-Income Parents Offer Snacks to Children: How Feeding Rationale Influences Snack Frequency and Adherence to Dietary Recommendations.

    Science.gov (United States)

    Blaine, Rachel E; Fisher, Jennifer Orlet; Taveras, Elsie M; Geller, Alan C; Rimm, Eric B; Land, Thomas; Perkins, Meghan; Davison, Kirsten K

    2015-07-21

    Although American children snack more than ever before, the parental role in promoting snacking is not well understood. In 2012-2013 at baseline in an intervention study to prevent childhood obesity in low-income Massachusetts communities, n = 271 parents of children aged 2-12 years completed surveys regarding nutritive and non-nutritive reasons they offered children snacks, demographics, and dietary factors. An analysis of variance demonstrated that parents reported offering snacks (mean/week; standard deviation (SD)) for nutritive reasons like promoting growth (x̄ = 2.5; SD 2.2) or satisfying hunger (x̄ = 2.4; SD 2.1) almost twice as often as non-nutritive reasons like keeping a child quiet (x̄ = 0.7; SD 1.5) or celebrating events/holidays (x̄ = 0.8; SD 1.1). Parents reported giving young children (2-5 years) more snacks to reward behavior (1.9 vs. 1.1, p parents of older children (6-12 years). Multivariable logistic regression models were used to obtain adjusted odds ratios, which indicated reduced child adherence to dietary recommendations when parents offered snacks to reward behavior (Odds Ratio (OR) = 0.83; 95% Confidence Interval (CI) 0.70-0.99), celebrate events/holidays (OR = 0.72; 95% CI 0.52-0.99), or achievements (OR = 0.82; 95% CI 0.68-0.98). Parental intentions around child snacking are likely important targets for obesity prevention efforts.

  5. Surfactant-free CZTS nanoparticles as building blocks for low-cost solar cell absorbers

    OpenAIRE

    Zaberca, Oana; Oftinger, Frédéric; Chane-Ching, Jean-Yves; Datas, Lucien; Lafond, Alain; Puech, Pascal; Balocchi, Andréa; Lagarde, Delphine; Marie, Xavier

    2012-01-01

    A process route for the fabrication of solvent-redispersible, surfactant-free Cu2ZnSnS4 (CZTS) nanoparticles has been designed with the objective to have the benefit of a simple sulfide source which advantageously acts as (i) a complexing agent inhibiting crystallite growth, (ii) a surface additive providing redispersion in low ionic strength polar solvents and (iii) a transient ligand easily replaced by an carbon-free surface additive. This multifunctional use of the sulfide source has been ...

  6. Renewable and low-carbon energies as mitigation options of climate change for China

    OpenAIRE

    Urban, F.; Benders, R.M.J.; Moll, H.C.

    2009-01-01

    This article discusses how renewable and low-carbon energies can serve as mitigation options of climate change in China's power sector. Our study is based on scenarios developed in PowerPlan, a bottom-up model simulating a countries' power sector and its emissions. We first adjusted the model to China's present-day economy and power sector. We then developed different scenarios based on story lines for possible future developments in China. We simulated China's carbon-based electricity produc...

  7. Hair as Biomarker of Fluoride Exposure in a Fluoride Endemic Area and a Low Fluoridated Area

    OpenAIRE

    Parimi, Nalini; V. Viswanath; Kashyap, Bina; Patil, Pavan Uday

    2013-01-01

    Aim: The aim of the present study was to determine whether hair could be used as biomarker of fluoride exposure. Materials and Methods: The study was carried out on 30 people living in an endemically fluoridated area and a low fluoridated area. Samples of hair from the occipital were taken and subjected to fluoride analysis by a fluoride ion electrode. Results: Lower fluoride levels in water supplies correlated with lower levels of fluoride in hair and more over higher fluoride levels in wate...

  8. Asynchronous interaction, online technologies self-efficacy and self-regulated learning as predictors of academic achievement in an online class

    Science.gov (United States)

    McGhee, Rosie M. Hector

    This research is a correlational study of the relationship among the independent variables: asynchronous interaction, online technologies self-efficacy, and self-regulated learning, and the dependent variable; academic achievement. This study involves an online computer literacy course at a local community college. Very little research exists on the relationship among asynchronous interaction, online technologies self-efficacy and self-regulated learning on predicting academic achievement in an online class. Liu (2008), in his study on student interaction in online courses, concluded that student interaction is a complex issue that needs more research to increase our understanding as it relates to distance education. The purpose of this study was to examine the relationships between asynchronous interaction, online technologies self-efficacy, self-regulated learning and academic achievement in an online computer literacy class at a community college. The researcher used quantitative methods to obtain and analyze data on the relationships among the variables during the summer 2010 semester. Forty-five community college students completed three web-based self-reporting instruments: (a) the GVU 10th WWW User Survey Questionnaire, (b) the Online Technologies Self-Efficacy Survey, and (c) selected items from the Motivated Strategies for Learning Questionnaire. Additional data was obtained from asynchronous discussions posted on Blackboard(TM) Learning Management System. The results of this study found that there were statistically significant relationships between asynchronous interaction and academic achievement (r = .55, p self-efficacy and academic achievement (r = .50, p self-regulated learning and academic achievement ( r = -.02, p interested in taking online teaching and learning to the next level.

  9. Composite hemangioendothelioma and its classification as a low-grade malignancy.

    Science.gov (United States)

    McNab, Patricia Moody; Quigley, Brian Christopher; Glass, L Frank; Jukic, Drazen M

    2013-06-01

    Hemangioendotheliomas are vascular neoplasms occupying a spectrum of biological potential ranging from benign to low-grade malignancy. Composite hemangioendothelioma (CH) is one of the less commonly encountered variants exhibiting a mixture of elements of other hemangioendothelioma subtypes, such as epithelioid, retiform, and spindle cell. Some authors have identified areas histopathologically equivalent to angiosarcoma within CH, raising the question of the true nature of this neoplasm. Although CH recurs locally, there are only 3 reported cases which metastasized. To date, 26 cases (including the present case) have been described in the literature. Herein, we describe a unique case of CH arising in the background of previous radiation therapy and long-standing lymphedema (classically associated with the development of angiosarcoma-Stewart-Treves syndrome) that harbored higher grade areas but behaved as a low-grade malignant neoplasm. This, in conjunction with the many reported cases of CH-harboring angiosarcoma-like areas, and the occasional association with a history of lymphedema, raises the question of whether this variant of hemangioendothelioma may actually be an angiosarcoma that behaves prognostically better than the conventional type. After careful study of the natural disease progression of the current case and review of the literature, we discuss justification for the continued classification of CH as a low-grade malignancy. PMID:23694827

  10. TRPV Channels in Mast Cells as a Target for Low-Level-Laser Therapy

    Directory of Open Access Journals (Sweden)

    Lina Wang

    2014-06-01

    Full Text Available Low-level laser irradiation in the visible as well as infrared range is applied to skin for treatment of various diseases. Here we summarize and discuss effects of laser irradiation on mast cells that leads to degranulation of the cells. This process may contribute to initial steps in the final medical effects. We suggest that activation of TRPV channels in the mast cells forms a basis for the underlying mechanisms and that released ATP and histamine may be putative mediators for therapeutic effects.

  11. Low-reactive circulating fluidized bed combustion (CFBC) fly ashes as source material for geopolymer synthesis.

    Science.gov (United States)

    Xu, Hui; Li, Qin; Shen, Lifeng; Zhang, Mengqun; Zhai, Jianping

    2010-01-01

    In this contribution, low-reactive circulating fluidized bed combustion (CFBC) fly ashes (CFAs) have firstly been utilized as a source material for geopolymer synthesis. An alkali fusion process was employed to promote the dissolution of Si and Al species from the CFAs, and thus to enhance the reactivity of the ashes. A high-reactive metakaolin (MK) was also used to consume the excess alkali needed for the fusion. Reactivities of the CFAs and MK were examined by a series of dissolution tests in sodium hydroxide solutions. Geopolymer samples were prepared by alkali activation of the source materials using a sodium silicate solution as the activator. The synthesized products were characterized by mechanical testing, scanning electron microscopy (SEM), X-ray diffractography (XRD), as well as Fourier transform infrared spectroscopy (FTIR). The results of this study indicate that, via enhancing the reactivity by alkali fusion and balancing the Na/Al ratio by additional aluminosilicate source, low-reactive CFAs could also be recycled as an alternative source material for geopolymer production.

  12. Studies on Some Nitramine based Low Vulnerability Ammunition Propellants with Cellulose Acetate as a Binder

    Directory of Open Access Journals (Sweden)

    A.G.A. Pillai

    1996-04-01

    Full Text Available Several formulations of propellants based on RDX as an energetic solid ingredients and cellulose acetate (CA as a binder were processed using either dioctyl pthalate(DOP or tracetin(TA as plastisizer and a small amount of nitrocellulose(NC. The Performance of these propellants was evaluated on the basis of closed vessel firing data. The vulnerability aspects of these formulations were compared with those of conventional picrite propellant, NQ on the basis of their ignition temperatures and sensitivity to friction and impact. Triacetin was found to be better plasticizer than DOP for CA binder. Some RDX/CA/TA/NC/-based propellants were found to have energy levels comparable with NQ propellant and had less sensitivity to heat, impact and friction, and therefore have the potential for being used as low-vulnerability ammunition propellants for gun applications.

  13. Clinical Trials Infrastructure as a Quality Improvement Intervention in Low- and Middle-Income Countries.

    Science.gov (United States)

    Denburg, Avram; Rodriguez-Galindo, Carlos; Joffe, Steven

    2016-06-01

    Mounting evidence suggests that participation in clinical trials confers neither advantage nor disadvantage on those enrolled. Narrow focus on the question of a "trial effect," however, distracts from a broader mechanism by which patients may benefit from ongoing clinical research. We hypothesize that the existence of clinical trials infrastructure-the organizational culture, systems, and expertise that develop as a product of sustained participation in cooperative clinical trials research-may function as a quality improvement lever, improving the quality of care and outcomes of all patients within an institution or region independent of their individual participation in trials. We further contend that this "infrastructure effect" can yield particular benefits for patients in low- and middle-income countries (LMICs). The hypothesis of an infrastructure effect as a quality improvement intervention, if correct, justifies enhanced research capacity in LMIC as a pillar of health system development. PMID:27216089

  14. Reasons for non-immunization of children in an urban, low income group in North India.

    Science.gov (United States)

    Mathew, Joseph L; Babbar, Harsh; Yadav, Sangita

    2002-07-01

    A study was undertaken on 500 children under the age of 5 years belonging to a low income group. All were attending the paediatrics outpatient department of a large teaching hospital in New Delhi, India. Only 25% were found to have received complete primary immunization as per the National Immunization Schedule (bacille Calmette-Guérin at birth, three doses of diphtheria, pertussis and tetanus and oral poliovirus vaccine at 6,10 and 14 weeks and measles vaccine at 9 months). The major reasons for non-immunization of the children were: migration to a native village (26.4%); domestic problems (9.6%); the immunization centre was located too far from their home (9.6%); and the child was unwell when the vaccination was due (9%). Twelve per cent of mothers could not give any reason for non-immunization. In addition to the migration of children to rural areas, the other significant finding was an indirect effect of intensive OPV administration as part of polio eradication initiative. The lack of awareness and fear of side effects constituted a small minority of reasons for non-immunization.

  15. Emotional intelligence as a predictor of self-efficacy among students with different levels of academic achievement at Kermanshah University of Medical Sciences

    Directory of Open Access Journals (Sweden)

    AMENEH GHARETEPEH

    2015-04-01

    Full Text Available Introduction: studies have indicated that emotional intelligence is positively related to self-efficacy and can predict the academic achievement. The present study aimed to investigate the role of emotional intelligence in identifying self-efficacy among the students of Public Health School with different levels of academic achievement. Methods: This correlational study was conducted on all the students of Public Health School. 129 students were included in the study through census method. Data were collected using Emotional Intelligence and self-efficacy questionnaires and analyzed using descriptive statistics and regression analysis by SPSS 14. Results: The average score of students with high academic achievement was higher in self-efficacy (39.78±5.82 and emotional intelligence (117.07±10.33 variables and their components than that of students with low academic achievement (39.17±5.91, 112.07±13.23. The overall emotional intelligence score to predict self-efficacy explanation was different among students with different levels of academic achievement (p<0.001. Self-efficacy structure was explained through self-awareness and self-motivation components in students with low academic achievement (r=0.571. In students with high academic achievement, self-awareness, selfmotivation and social consciousness played an effective role in explaining self-efficacy (r=0.677, p<0.001. Conclusion: Emotional intelligence and self-efficacy play an important role in achieving academic success and emotional intelligence can explain self-efficacy. Therefore, it is recommended to teach emotional intelligence skills to students with low academic achievement through training workshops.

  16. Giant band bending induced by Ag on InAs(110) surfaces at low temperature

    Science.gov (United States)

    Aristov, V. Yu.; Le Lay, G.; Vinh, Le Thanh; Hricovini, K.; Bonnet, J. E.

    1993-01-01

    We show by synchrotron radiation photoemission spectroscopy [G. Le Lay, V. Yu Aristov, J. Kanski, P. O. Nilsson, U. O. Karlsson, K. Hricovini, and J. E. Bonnet (unpublished)] (core levels and valence band) as well as by Kelvin probe measurements, both under illumination and in the dark, at low temperature (LT) T~=20 K and room temperature (RT) T~=300 K, that upon deposition of minute amounts of silver (about 0.01-0.1 monolayer) onto in situ well-cleaved, highly doped, n- and p-type InAs(110) surfaces, one induces a giant movement of the Fermi level EF into the conduction band. We thus create a two-dimensional (2D) electron gas at the surface (strong downwards band bending): as a matter of fact, we do observe emission of electrons from filled states up to the EF placed far above the conduction-band minimum (CBM). It is also shown that the growth is laminar at LT, while it follows a Volmer-Weber mode at RT, with indications of chemical interactions between the Ag and In atoms at both temperatures. At LT the deposited atoms interact with the dangling bonds of the In atoms and saturate them for θ~=1 monolayer (ML). At low coverages and LT, the individual Ag atoms create donorlike surface states (SS) (adsorption-induced states) and EF can be pinned by these SS in the conduction band. This leads to the formation of a 2D electron channel at the InAs surface already at θ~=0.01-0.1 ML for both types of semiconductors. At higher coverages one observes the onset of metallization for both temperatures and Ag clusters can produce another type of SS, typically metal-induced gap states near the CBM. These proposals, as well as the experimental facts, are discussed in the light of the current theoretical models of Schottky-barrier formation.

  17. Emesis as a Screening Diagnostic for Low Dose Rate (LDR) Total Body Radiation Exposure.

    Science.gov (United States)

    Camarata, Andrew S; Switchenko, Jeffrey M; Demidenko, Eugene; Flood, Ann B; Swartz, Harold M; Ali, Arif N

    2016-04-01

    Current radiation disaster manuals list the time-to-emesis (TE) as the key triage indicator of radiation dose. The data used to support TE recommendations were derived primarily from nearly instantaneous, high dose-rate exposures as part of variable condition accident databases. To date, there has not been a systematic differentiation between triage dose estimates associated with high and low dose rate (LDR) exposures, even though it is likely that after a nuclear detonation or radiologic disaster, many surviving casualties would have received a significant portion of their total exposure from fallout (LDR exposure) rather than from the initial nuclear detonation or criticality event (high dose rate exposure). This commentary discusses the issues surrounding the use of emesis as a screening diagnostic for radiation dose after LDR exposure. As part of this discussion, previously published clinical data on emesis after LDR total body irradiation (TBI) is statistically re-analyzed as an illustration of the complexity of the issue and confounding factors. This previously published data includes 107 patients who underwent TBI up to 10.5 Gy in a single fraction delivered over several hours at 0.02 to 0.04 Gy min. Estimates based on these data for the sensitivity of emesis as a screening diagnostic for the low dose rate radiation exposure range from 57.1% to 76.6%, and the estimates for specificity range from 87.5% to 99.4%. Though the original data contain multiple confounding factors, the evidence regarding sensitivity suggests that emesis appears to be quite poor as a medical screening diagnostic for LDR exposures. PMID:26910032

  18. A Qualitative Study of Self-Esteem, Peer Affiliation, and Academic Outcome among Low Achieving Students in Hong Kong

    Science.gov (United States)

    Leung, Chi-hung; Choi, Eudora

    2010-01-01

    Background: A limited amount of research has been conducted on children and adolescents who are low achievers. In Hong Kong, educators describe low achieving students in terms of academic performance, they seldom focus on socio-emotional aspects, such as self-esteem, peer affiliation, and inter-personal relationships. However, low achieving…

  19. Outgassing characteristics of F82H ferritic steel as a low activation material for fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Odaka, Kenji; Satou, Osamu [Hitachi Ltd., Tsuchiura, Ibaraki (Japan). Mechanical Engineering Research Lab.; Ootsuka, Michio; Abe, Tetsuya; Hara, Shigemitsu; Takatsu, Hideyuki; Enoeda, Mikio

    1997-09-01

    Outgassing characteristics of F82H ferritic steel as a low activation material for the blanket of fusion device were investigated. A test chamber was constructed by welding F82H ferritic steel plates. The inner surface of the chamber was buffed and electropolished. The test chamber was degassed by the prebaking at temperature of 350degC for 20 h in vacuum. Then outgassing rates of the test chamber were measured by the throughput method as a function of pumping time for the cases that the test chamber was baked and not baked. The typical outgassing rate after baking at 250degC for 24 h was 3 x 10{sup -9} Pa{center_dot}ms{sup -1} and it seems that this value is sufficiently small to produce pressures at least as low as 10{sup -9} Pa in the vacuum chamber made of F82H ferritic steel. In the pump-down of the test chamber without baking after exposure to air, the outgassing rate decreases with pumping time and reached 1 x 10{sup -7} Pa{center_dot}ms{sup -1} at t = 10{sup 5} s. The activation energy of hydrogen in bulk diffusion in the F82H ferritic steel was measured and found to be 7 kcal/mol. (author)

  20. Low-carbon communities as a context for individual behavioural change

    Energy Technology Data Exchange (ETDEWEB)

    Heiskanen, Eva; Johnson, Mikael; Saastamoinen, Mika [National Consumer Research Centre, P.O. Box 5, 00531 Helsinki (Finland); Robinson, Simon [Manchester Knowledge Capital, Churchgate House, 56 Oxford Street, Manchester, M60 7HJ (United Kingdom); Vadovics, Edina [Green Dependent Sustainable Solutions Association, Eva u. 4, 2100 Goedoelloe (Hungary)

    2010-12-15

    Previous attempts to change energy-related behaviour were targeted at individuals as consumers of energy. Recent literature has suggested that more focus should be placed on the community level and that energy users should be engaged in the role of citizens, and not only that of consumers. This article analyses different types of emerging low-carbon communities as a context for individual behavioural change. The focus is on how these communities offer solutions to problems in previous attempts to change individual behaviour. These problems include social dilemmas, social conventions, socio-technical infrastructures and the helplessness of individuals. Different community types are examined, including geographical communities as well as sector-based, interest-based and smart mob communities. Through four case studies representing each of these community types, we examine how different communities reframe problems on the individual level to reduce carbon emissions. On the basis of an analysis of the strengths and weaknesses of various community solutions, implications are drawn for further research and for the design and support of low-carbon communities. (author)

  1. Dorsal root ganglion compression as an animal model of sciatica and low back pain

    Institute of Scientific and Technical Information of China (English)

    Xiao-Yu Lin; Jing Yang; Hui-Ming Li; San-Jue Hu; Jun-Ling Xing

    2012-01-01

    As sciatica and low back pain are among the most common medical complaints,many studies have duplicated these conditions in animals.Chronic compression of the dorsal root ganglion (CCD) is one of these models.The surgery is simple:after exposing the L4/L5 intervertebral foramina,stainless steel rods are implanted unilaterally,one rod for each vertebra,to chronically compress the lumbar dorsal root ganglion (DRG).Then,CCD can be used to simulate the clinical conditions caused by stenosis,such as a laterally herniated disc or foraminal stenosis.As the intraforaminal implantation of a rod results in neuronal somal hyperexcitability and spontaneous action potentials associated with hyperalgesia,spontaneous pain,and mechanical allodynia,CCD provides an animal model that mimics radicular pain in humans.This review concerns the mechanisms of neuronal hyperexcitability,focusing on various patterns of spontaneous discharge including one possible pain signal for mechanical allodynia-evoked bursting.Also,new data regarding its significant property of maintaining peripheral input are also discussed.Investigations using this animal model will enhance our understanding of the neural mechanisms for low back pain and sciatica.Furthermore,the peripheral location of the DRG facilitates its use as a locus for controlling pain with minimal central effects,in the hope of ultimately uncovering analgesics that block neuropathic pain without influencing physiological pain.

  2. N,N-dimethylbiguanide complexes displaying low cytotoxicity as potential large spectrum antimicrobial agents.

    Science.gov (United States)

    Olar, Rodica; Badea, Mihaela; Marinescu, Dana; Chifiriuc, Mariana-Carmen; Bleotu, Coralia; Grecu, Maria Nicoleta; Iorgulescu, Emilia-Elena; Lazar, Veronica

    2010-07-01

    The new complexes M(DMBG)(2)(ClO(4))(2) (M:Mn, Ni, Cu and Zn; DMBG: N,N-dimethylbiguanide) have been synthesized and characterized by IR, EPR, (1)H NMR, (13)C NMR as well as electronic spectroscopy data. Complex [Ni(DMBG)(2)](ClO(4))(2).2DMF (DMF: N,N-dimethylformamide) crystallizes in the monoclinic P2(1)/c space group while [Cu(DMBG)(2)](ClO(4))(2) adopt monoclinic P21/c space group as X-ray single crystal data indicate. The redox behavior of complexes was investigated by cyclic voltammetry. The metal-free N,N-dimethylbiguanide and complexes exhibit specific anti-infective properties as demonstrated the low MIC values, a large antimicrobial spectrum and also inhibit the ability of Pseudomonas aeruginosa and Staphylococcus aureus strains to colonize the inert surfaces. The complexes exhibit also a low cytotoxicity levels on HeLa cells.

  3. Low Serum Concentration of Obestatin as a Predictor of Mortality in Maintenance Hemodialysis Patients

    Directory of Open Access Journals (Sweden)

    Ilia Beberashvili

    2013-01-01

    Full Text Available Obestatin, a proposed anorexigenic gut hormone, has been shown to have a number of beneficial cardiotropic effects in experimental studies. We hypothesized that obestatin alteration in hemodialysis patients may link to clinical outcomes. This cross-sectional study with prospective followup for almost 4 years was performed on 94 prevalent hemodialysis patients. Obestatin, leptin, proinflammatory cytokines (tumor necrosis factor-α [TNF-α], interleukin-6, and various nutritional markers were measured. Patients with low obestatin levels, defined as a level less than median, had a worse all-cause mortality and cardiovascular mortality. The crude all-cause (HR 2.23, 95% CI 1.17 to 4.24 and cardiovascular mortality hazard ratios (HR 4.03, 95% CI 1.27 to 12.76 in these patients continued to be significant after adjustment for various confounders for all-cause mortality. Across the four obestatin-TNF-α categories, the group with low obestatin and high TNF-α (above median level exhibited a worse outcome in both all-cause mortality and cardiovascular mortality. Clinical characteristics of patients in low obestatin high TNF-α group did not differ from other obestatin-TNF-α categorized groups. In summary, low serum obestatin concentration is an independent predictor of mortality in prevalent hemodialysis patients. Novel interactions were observed between obestatin and TNF-α, which were associated with mortality risk, especially those due to cardiovascular causes.

  4. Low-mass black holes as the remnants of primordial black hole formation

    CERN Document Server

    Greene, Jenny E

    2012-01-01

    This article documents our ongoing search for the elusive "intermediate-mass" black holes. These would bridge the gap between the approximately ten solar mass "stellar-mass" black holes that are the end-product of the life of a massive star, and the "supermassive" black holes with masses of millions to billions of solar masses found at the centers of massive galaxies. The discovery of black holes with intermediate mass is the key to understanding whether supermassive black holes can grow from stellar-mass black holes, or whether a more exotic process accelerated their growth only hundreds of millions of years after the Big Bang. Here we focus on searches for black holes with masses of 10^4-10^6 solar masses that are found at galaxy centers. We will refer to black holes in this mass range as "low-mass" black holes, since they are at the low-mass end of supermassive black holes. We review the searches for low-mass black holes to date and show tentative evidence, from the number of low-mass black holes that are ...

  5. A comparison of concrete and formal science instruction upon science achievement and reasoning ability of sixth grade students

    Science.gov (United States)

    Saunders, Walter L.; Shepardson, Daniel

    Several recent studies suggest concrete learners make greater gains in student achievement and in cognitive development when receiving concrete instruction than when receiving formal instruction. This study examined the effect of concrete and formal instruction upon reasoning and science achievement of sixth grade students. Four intact classes of sixth grade students were randomly selected into two treatment groups; concrete and formal. The treatments were patterned after the operational definitions published by Schneider and Renner (1980). Pretest and posttest measures were taken on the two dependent variables; reasoning, measured with Lawson's Classroom Test of Formal Reasoning, and science achievement, measured with seven teacher made tests covering the following units in a sixth grade general science curriculum: Chemistry, Physics, Earth Science, Cells, Plants, Animals, and Ecology. Analysis of covariance indicated significantly higher levels (better than 0.05 and in some cases 0.01) of performance in science achievement and cognitive development favoring the concrete instruction group and a significant gender effect favoring males.

  6. An investigation on the ultra-low energy As ion implantation process and the dopant behaviour during thermal processing

    CERN Document Server

    Whelan, S

    2001-01-01

    Characterisation of the ultra-low energy (ULE) As ion implantation profile (dopant and damage distributions) in Si has been achieved using medium energy ion scattering (MEIS) and secondary ion mass spectrometry (SIMS), in conjunction with a sputter profile deconvolution code (IMPETUS). The Si damage re-growth, dopant substitutionality, diffusion and retention processes that occur during thermal annealing have been investigated as a function of the implant damage and anneal gas ambient. It has been shown that for dopant distributions with a range less than 100A, significant error in the SIMS depth scale occurs when assuming a constant erosion rate throughout sputtering. The sputter depth profile deconvolution code IMPETUS has been used to quantify the errors associated with this assumption. Accurate simulation of the ULE As ion implant process in Si incorporating oxide accumulation effects (segregation) and self-sputtering has been obtained and validated with high resolution MEIS measurements. The code calcula...

  7. Low-temperature laser assisted CBE-growth of AlGaAs

    Science.gov (United States)

    Jothilingam, R.; Farrell, T.; Joyce, T. B.; Goodhew, P. J.

    1998-06-01

    We report preliminary studies of low-temperature (335-400°C) chemical beam epitaxial (CBE) growth of Al xGa 1- xAs on GaAs(0 0 1) using triethylgallium (TEG), trimethylaminealane (TMAA) and thermally precracked Arsine (AsH 3) as precursors. We also report results of Ar + laser assisted chemical beam epitaxial growth over the same temperature range. The growth rate for both assisted and unassisted growth as a function of substrate temperature, laser power and precursor beam pressures was determined using laser reflectometry in which the Ar + laser was also used as the probe. In the nonlaser assisted growth Al incorporation is observed to be significantly higher than would be expected at the normal growth temperature of 500°C. With laser assistance the Al concentration, while higher than that at normal growth temperatures, is less than that without laser assistance and the growth rate is higher. These observations, which extended Abernathy's early results to higher nominal Al concentration, are discussed in terms of the relative enhancement of the decomposition of TEG and the alane during laser assistance. Using literature values of the refractive index of AlGaAs alloys at the growth temperature, laser reflectometry was used to monitor both composition and growth rate over a range of growth temperatures. Reflectometry data were compared with the results of Auger Electron Microscopy (AES) and Dektak stylus profiling.

  8. Distant Low-mass Galaxies as an Incisive Tool to Explore Galaxy Formation and Evolution

    Science.gov (United States)

    Guo, Yicheng; Koo, David C.; Faber, Sandra M.; Rafelski, Marc; Trump, Jonathan R.

    2016-06-01

    Distant low-mass galaxies, with stellar mass below 10^9.5 solar mass, are key to our understanding of galaxy formation. They are the building blocks or progenitors of massive galaxies, e.g., our Milky Way. They are also the most sensitive probes of the feedback mechanisms that regulate the star formation, due to their shallow gravitational potential wells. Our knowledge of distant low-mass galaxies is, however, very limited because of the difficulty of observing them as well as modeling them. I will present my work on using deep multi-wavelength photometric and spectroscopic surveys to study three aspects of low-mass galaxies when the universe was about 7-billion-year old (0.5≤z≤1): star formation history, gas-phase metallicity, and morphology. I will discuss how to use them to understand the physical mechanisms that control the mass--energy--chemical cycles in galaxies. The three aspects also shed light on the relation between galaxies and their dark matter halos.

  9. The theory of reasoned action as a model of marijuana use: tests of implicit assumptions and applicability to high-risk young women.

    Science.gov (United States)

    Morrison, Diane M; Golder, Seana; Keller, Thomas E; Gillmore, Mary Rogers

    2002-09-01

    The theory of reasoned action (TRA) is used to model decisions about substance use among young mothers who became premaritally pregnant at age 17 or younger. The results of structural equation modeling to test the TRA indicated that most relationships specified by the model were significant and in the predicted direction. Attitude was a stronger predictor of intention than norm, but both were significantly related to intention, and intention was related to actual marijuana use 6 months later. Outcome beliefs were bidimensional, and positive outcome beliefs, but not negative beliefs, were significantly related to attitude. Prior marijuana use was only partially mediated by the TRA variables; it also was directly related to intentions to use marijuana and to subsequent use.

  10. Flammability of radiation cross-linked low density polyethylene as an insulating material for wire and cable

    Science.gov (United States)

    Basfar, A. A.

    2002-03-01

    Various formulations of low-density polyethylene blended with ethylene vinyl acetate were prepared to improve the flame retardancy for wire and cable applications. The prepared formulations were cross-linked by γ-rays to 50, 100, 150 and 200 kGy in the presence of trimethylolpropane triacrylate (TMPTA). The effect of thermal aging on mechanical properties of these formulations were investigated. In addition, the influence of various combinations of aluminum trihydroxide and zinc borate as flame retardant fillers on the flammability was explored. Limiting oxygen index (LOI) and average extent of burning were used to characterize the flammability of investigated formulations. An improved flame retardancy of low density polyethylene was achieved by various combinations of flame ratardant fillers and cross-linking by gamma radiation.

  11. Enhanced terahertz emission from a multilayered low temperature grown GaAs structure

    Science.gov (United States)

    Rihani, Samir; Faulks, Richard; Beere, Harvey E.; Farrer, Ian; Evans, Michael; Ritchie, David A.; Pepper, Michael

    2010-03-01

    We report the use of a multilayered structure comprising of alternating layers of low temperature grown GaAs and high temperature grown AlAs, as a terahertz (THz) photoconductive antenna emitter and receiver. Devices based on 10×10 μm2 mesa defined photoconductive gaps were fabricated on the multilayered structure, and a comparison made to conventional planar devices. The mesa defined photoconductive antennas allowed successive contact through the multilayered structure, which resulted in an increase in THz emission power and detection responsivity with increasing number of layers in contact with the antenna electrodes. A comparison with a conventional single layered device, processed in an identical mesa geometry, confirmed that the enhancement in THz emission is solely due to the multilayered nature of the device, whereas the improved receiver performance can be partially attributed to the mesa geometry.

  12. 2,5-PRODAN Derivatives as Highly Sensitive Sensors of Low Solvent Acidity

    Directory of Open Access Journals (Sweden)

    Alexandra H. Yoon

    2014-05-01

    Full Text Available Two 5-acyl-2-dimethylaminonaphthalene derivatives, one with a propionyl group and the other with a fused cyclohexanone ring, are investigated as sensors of H-bond-donating ability in protic solvents of low solvent acidity. Their fluorescence is highly quenched in protic solvents, and the quenching order of magnitude is linearly related to the H-bond-donating ability of the solvent as quantified by the solvent acidity (SA scale. As the solvent acidity increases from 0.15 to 0.40, the fluorescence for both is quenched by more than a factor of ten; thus, they are extremely sensitive sensors of the hydrogen-bond-donating ability in this weakly acidic range. Preferential solvation studies suggest that quenching occurs from a doubly H-bonded excited state.

  13. Geo-polymers as Candidates for the Immobilisation of Low- and Intermediate-Level Waste

    International Nuclear Information System (INIS)

    Geo-polymers should be serious waste form candidates for intermediate level waste (ILW), insofar as they are more durable than Portland cement and can pass the PCT-B test for high-level waste. Thus an alkaline ILW could be considered to be satisfactorily immobilised in a geo-polymer formulation. However a simulated Hanford tank waste was found to fail the PCT-B criterion even for a waste loading as low as 5 wt%, very probably due to the formation of a soluble sodium phosphate compound(s). This suggests that it could be worth developing a 'mixed' GP waste form in which the amorphous material can immobilize cations and a zeolitic component to immobilize anions. The PCT-B test is demonstrably subject to significant saturation effects, especially for relatively soluble waste forms. (authors)

  14. Constructivism as a Model for Cognitive Development and (Eventually) Learning (Orange Juice Experiment): The Development of Proportional Reasoning in the Child and Adolescent.

    Science.gov (United States)

    Noelting, Gerald

    This study examined the development of the rational number concept as a ratio. Preliminary to the description of the study is an introduction discussing constructivism and equilibration. The study itself tests whether equilibration theory holds, and if so, what is the nature of its "phases" and whether these are found at each of the "periods" of…

  15. Low dose intravesical heparin as prophylaxis against recurrent noninvasive (stage Ta) bladder cancer

    DEFF Research Database (Denmark)

    Bitsch, M; Hermann, G G; Andersen, J P;

    1990-01-01

    A controlled randomized clinical trial was conducted to examine the efficacy of topical low dose heparin (0.125 gm./l., 25,000 units per l.) as prophylaxis against recurrent noninvasive (stage Ta) transitional cell bladder cancer. Transurethral tumor resection was done with irrigation fluid...... containing either 1.5% glycine with heparin or glycine solution alone. Tumor recurrence was determined by cystoscopy 4 to 6 months later. There were 70 patients evaluated: 38 in the heparin and 32 in the control group, respectively. The recurrence rate (heparin 74%, control 66%) and the median number...... of recurrences (heparin 3, range 1 to 15 and control 3, range 1 to 30) were similar (p greater than 0.05) in the 2 groups of patients. These observations show that low dose heparin administered in the irrigation fluid during transurethral resection does not decrease the recurrence rate of noninvasive (stage Ta...

  16. Low-Redshift Lyman Limit Systems as Diagnostics of Cosmological Inflows and Outflows

    CERN Document Server

    Hafen, Z; Angles-Alcazar, D; Keres, D; Feldmann, R; Chan, T K; Quataert, E; Murray, N; Hopkins, P F

    2016-01-01

    We use cosmological hydrodynamic simulations with stellar feedback from the FIRE project to study the physical nature of Lyman limit systems (LLSs) at z~2) tend to have higher metallicities ([X/H] ~ -0.5) while very low metallicity ([X/H] < -2) LLSs are typically associated with gas infalling from the intergalactic medium. However, most LLSs occupy an intermediate region in metallicity-radial velocity space, for which there is no clear trend between metallicity and radial kinematics. Metal-enriched inflows arise in the FIRE simulations as a result of galactic winds that fall back onto galaxies at low redshift. The overall simulated LLS metallicity distribution has a mean (standard deviation) [X/H] = -0.9 (0.4) and does not show significant evidence for bimodality, in contrast to recent observational studies but consistent with LLSs arising from halos with a broad range of masses and metallicities.

  17. Low-temperature characteristics of two-color InAs/InP quantum dots laser

    Institute of Scientific and Technical Information of China (English)

    Shiguo Li; Qian Gong; Xinzhong Wang; Li Yue; Oingbo Liu; Hailong Wang

    2012-01-01

    We report on the lasing characteristics of a two-color InAs/InP quantum dots (QDs) laser at a low temperature.Two lasing peaks with a tunable gap are simultaneously observed.At a low temperature of 80 K,a tunable range greater than a 20-nm wavelength is demonstrated by varying the injection current from 30 to 500 mA.Under a special condition,we even observe three lasing peaks,which are in contrast to those observed at room temperature.The temperature coefficient of the lasing wavelength was obtained for the two colors in the 80-280 K temperature range,which is lower than that of the reference quantum well (QW) laser working in the same wavelength region.

  18. Low cost high efficiency GaAs monolithic RF module for SARSAT distress beacons

    Science.gov (United States)

    Petersen, W. C.; Siu, D. P.; Cook, H. F.

    1991-12-01

    Low cost high performance (5 Watts output) 406 MHz beacons are urgently needed to realize the maximum utilization of the Search and Rescue Satellite-Aided Tracking (SARSAT) system spearheaded in the U.S. by NASA. Although current technology can produce beacons meeting the output power requirement, power consumption is high due to the low efficiency of available transmitters. Field performance is currently unsatisfactory due to the lack of safe and reliable high density batteries capable of operation at -40 C. Low cost production is also a crucial but elusive requirement for the ultimate wide scale utilization of this system. Microwave Monolithics Incorporated (MMInc.) has proposed to make both the technical and cost goals for the SARSAT beacon attainable by developing a monolithic GaAs chip set for the RF module. This chip set consists of a high efficiency power amplifier and a bi-phase modulator. In addition to implementing the RF module in Monolithic Microwave Integrated Circuit (MMIC) form to minimize ultimate production costs, the power amplifier has a power-added efficiency nearly twice that attained with current commercial technology. A distress beacon built using this RF module chip set will be significantly smaller in size and lighter in weight due to a smaller battery requirement, since the 406 MHz signal source and the digital controller have far lower power consumption compared to the 5 watt power amplifier. All the program tasks have been successfully completed. The GaAs MMIC RF module chip set has been designed to be compatible with the present 406 MHz signal source and digital controller. A complete high performance low cost SARSAT beacon can be realized with only additional minor iteration and systems integration.

  19. Motivos que levaram as gestantes a não se vacinarem contra H1N1 Reasons why pregnant women did not vaccinate against Influenza A H1N1

    Directory of Open Access Journals (Sweden)

    Carla Silvana Oliveira e Silva

    2013-06-01

    Full Text Available As grávidas constituem um grupo de risco para qualquer infecção devido à baixa imunidade que apresentam. Estudo descritivo com abordagem qualitativa, ancorada na Teoria das Representações Sociais que objetivou compreender os motivos que levaram as gestantes a não se vacinarem contra a Influenza A (H1N1. Participaram do estudo 10 mulheres que estavam grávidas no período da campanha de vacinação de 2010. Os dados foram coletados em maio de 2011 mediante entrevistas semiestruturadas e discutidas pela análise de conteúdo. A partir dos discursos foi possível identificar as várias representações que a vacina H1N1 tinha para essas mulheres no período de sua gestação, como elemento que causaria aborto e má formação do feto. Os motivos que levaram as gestantes a não se vacinarem contra a gripe H1N1 estão associados ao medo, à falta de informação e aos mitos e crenças que a população traz nas suas representações e nos seus valores culturais.Pregnant women constitute a risk group for any infection due to their low immunity condition. This is a descriptive study with a qualitative approach, grounded in the Theory of Social Representations that sought to understand the reasons why pregnant women did not vaccinate against influenza A (H1N1. The study included 10 women who were pregnant during the vaccination campaign of 2010. Data were collected in May 2011 through interviews and interpreted by content analysis. From the speeches it was possible to identify the various representations that the vaccine against H1N1 had for these women during their pregnancy as an element which would cause miscarriage and birth defects. The reasons why pregnant women did not vaccinate against H1N1 are associated with fear, lack of information and the myths and beliefs that people bring in their representations and their cultural values.

  20. Protein Rich Flour from Hyacinth Bean as Functional Food Ingredient with Low Glycemic Index

    Directory of Open Access Journals (Sweden)

    Ahmad Nafi’

    2013-06-01

    Full Text Available Protein-rich flour (PRF produced from Hyacinth bean (Lablab purpureus (L Sweet shows good potency as a functional food ingredient. The PRF was extracted from hyacinth bean using water followed by protein precipitation at its isoelectric point. The precipitate was neutralized using 1 N NaOH and the slurry was dried, ground and sieved. The objective of this research was to characterize the nutritive value of PRF i.e., protein content and amino acid profile, trypsin inhibitors activity, content of vitamins B1 and B2, the amylose and amylopectin ratio of starch and its glycemic index. The results showed that the PRF contained high protein (58.4±4.5%. The major amino acid was glutamic acid, while methionine was found as the limited amino acid of the PRF. The activity of trypsin inhibitor was low (20.4±1.6 unit/g. Moreover, PRF contains 0.2 and 3.6 mg/100 g of vitamins B1 and B2 respectively. With a high ratio of amylose (30.0±2.0% and high content of resistance starch (7.97 g/100 g, the PRF showed a low glycemic index (43.50. Based on its characteristics, this PRF can be promoted as a new food ingredient, especially for diabetic diet.