Sample records for achieving optimal growth

  1. Achieving optimal growth: lessons from simple metabolic modules

    NASA Astrophysics Data System (ADS)

    Goyal, Sidhartha; Chen, Thomas; Wingreen, Ned

    2009-03-01

    Metabolism is a universal property of living organisms. While the metabolic network itself has been well characterized, the logic of its regulation remains largely mysterious. Recent work has shown that growth rates of microorganisms, including the bacterium Escherichia coli, correlate well with optimal growth rates predicted by flux-balance analysis (FBA), a constraint-based computational method. How difficult is it for cells to achieve optimal growth? Our analysis of representative metabolic modules drawn from real metabolism shows that, in all cases, simple feedback inhibition allows nearly optimal growth. Indeed, product-feedback inhibition is found in every biosynthetic pathway and constitutes about 80% of metabolic regulation. However, we find that product-feedback systems designed to approach optimal growth necessarily produce large pool sizes of metabolites, with potentially detrimental effects on cells via toxicity and osmotic imbalance. Interestingly, the sizes of metabolite pools can be strongly restricted if the feedback inhibition is ultrasensitive (i.e. with high Hill coefficient). The need for ultrasensitive mechanisms to limit pool sizes may therefore explain some of the ubiquitous, puzzling complexity found in metabolic feedback regulation at both the transcriptional and post-transcriptional levels.

  2. Optimal growth of preterm infants.

    PubMed

    Corpeleijn, Willemijn E; Kouwenhoven, Stefanie M P; van Goudoever, Johannes B

    2013-01-01

    The cause of growth restriction in preterm infants is multifactorial, but it has been estimated that about 50% of the variance in early postnatal growth can be attributed to nutrition. Very low birth weight (VLBW) infants who were born small-for-gestational age (SGA) seem to have the highest risk to become growth restricted. Possibly, the intrauterine growth-retarded preterm infant is metabolically different from its appropriately grown counterpart and therefore has different nutritional needs. Neonatal nutrition and the resulting postnatal growth are major determinants in the short- and long-term outcomes of preterm neonates. Although having favorable effects on neurodevelopmental outcome, rapid postnatal weight gain after a period of nutritional restriction is associated with the development of insulin resistance and metabolic syndrome in later life. It seems likely that minimization of postnatal growth failure will decrease the need for catch-up growth and thereby decrease the risk of developing cardiovascular risk factors. Monitoring postnatal growth with current growth charts is complicated. Most growth charts that are currently being used are a reflection of current (nutritional) practices and are not a prescription of how VLBW should grow under optimal conditions. In addition to body weight, other aspects of growth such as lean body mass and length gain should also be taken into account when assessing the quality of postnatal growth. Noninvasive measurements of infant body composition are useful tools in evaluating the success of different nutritional interventions. However, all currently available methods have substantial drawbacks. A relatively new and promising method is air displacement plethysmography. This method still needs to be validated in preterm neonates. In conclusion, neonatal nutrition is a major determinant in the short- and long-term outcomes of preterm neonates. Monitoring postnatal growth is complicated by the lack of prescriptive growth charts and noninvasive measurements to assess the quality of growth. PMID:23428694

  3. Schools, school quality and achievement growth: Evidence from the Philippines

    Microsoft Academic Search

    Marigee P. Bacolod; Justin L. Tobias

    2006-01-01

    A broad literature seeks to assess the importance of schools, proxies for school quality, and family background on children's achievement growth using the education production function. Using rich data from the Philippines, we introduce and estimate a model that imposes little structure on the relationship between intake achievement and follow-up achievement and evaluate school performance based on this estimated relationship.

  4. Simulated annealing algorithm for optimal capital growth

    NASA Astrophysics Data System (ADS)

    Luo, Yong; Zhu, Bo; Tang, Yong

    2014-08-01

    We investigate the problem of dynamic optimal capital growth of a portfolio. A general framework that one strives to maximize the expected logarithm utility of long term growth rate was developed. Exact optimization algorithms run into difficulties in this framework and this motivates the investigation of applying simulated annealing optimized algorithm to optimize the capital growth of a given portfolio. Empirical results with real financial data indicate that the approach is inspiring for capital growth portfolio.

  5. DYNAMICS OF ACHIEVEMENT--A STUDY OF DIFFERENTIAL GROWTH OF ACHIEVEMENT OVER TIME.

    ERIC Educational Resources Information Center

    OKADA, TETSUO; AND OTHERS

    IN THE EDUCATIONAL OPPORTUNITY SURVEY, STANDARDIZED TESTS WERE GIVEN FOR GRADES 1, 3, 6, 9, AND 12. DATA WERE PRESENTED IN TERMS OF RACE, METROPOLITAN-NONMETROPOLITAN AREA, AND REGION. THE PURPOSES WERE TO--(1) PRESENT DATA SHOWING INCREASES IN ACHIEVEMENT, AND (2) CHARACTERIZE THE GROWTH IN ACHIEVEMENT BY RACE, METROPOLITAN-NONMETROPOLITAN AREA,…

  6. Parent Involvement and Science Achievement: A Latent Growth Curve Analysis

    ERIC Educational Resources Information Center

    Johnson, Ursula Yvette

    2011-01-01

    This study examined science achievement growth across elementary and middle school and parent school involvement using the Early Childhood Longitudinal Study-Kindergarten Class of 1998-1999 (ECLS-K). The ECLS-K is a nationally representative kindergarten cohort of students from public and private schools who attended full-day or half-day…

  7. Differential Growth Trajectories for Achievement Among Children Retained in First Grade: A Growth Mixture Model

    PubMed Central

    Chen, Qi; Hughes, Jan N.; Kwok, Oi-Man

    2013-01-01

    The authors investigated the differential effect of retention on the development of academic achievement from grade one to five on children retained in first grade over six years. Growth Mixture Model (GMM) analyses supported the existence of two distinct trajectory groups of retained children for both reading and math among 125 ethnically and linguistically diverse retained children. For each achievement domain, a low intercept/higher growth group (Class 1) and a high intercept/slower growth group (Class 2) were identified. Furthermore, Class 1 children were found to score lower on several measures of learning related skills (LRS) variables and were characterized by having poorer self-regulation and less prosocial behaviors, compared to the other group. Findings suggest that some children appear to benefit more from retention, in terms of higher reading and math growth, than others. Study findings have implications for selecting children into retention intervention and early intervention. PMID:24771882

  8. Differential Growth Trajectories for Achievement among Children Retained in First Grade: A Growth Mixture Model

    ERIC Educational Resources Information Center

    Chen, Qi; Hughes, Jan N.; Kwok, Oi-Man

    2014-01-01

    The authors investigated the differential effect of retention on the development of academic achievement from grades 1 to 5 on children retained in grade 1 over 6 years. Growth mixture model (GMM) analyses supported the existence of two distinct trajectory groups of retained children for both reading and math among 125 ethnically and…

  9. Limits of optimal control yields achievable with quantum controllers

    E-print Network

    Re-Bing Wu; Constantin Brif; Matthew R. James; Herschel Rabitz

    2015-05-03

    In quantum optimal control theory, kinematic bounds are the minimum and maximum values of the control objective achievable for any physically realizable system dynamics. For a given initial state of the system, these bounds depend on the nature and state of the controller. We consider a general situation where the controlled quantum system is coupled to both an external classical field (referred to as a classical controller) and an auxiliary quantum system (referred to as a quantum controller). In this general situation, the kinematic bound is between the classical kinematic bound (CKB), corresponding to the case when only the classical controller is available, and the quantum kinematic bound (QKB), corresponding to the ultimate physical limit of the objective's value. Specifically, when the control objective is the expectation value of a quantum observable (a Hermitian operator on the system's Hilbert space), the QKBs are the minimum and maximum eigenvalues of this operator. We present, both qualitatively and quantitatively, the necessary and sufficient conditions for surpassing the CKB and reaching the QKB, through the use of a quantum controller. The general conditions are illustrated by examples in which the system and controller are initially in thermal states. The obtained results provide a basis for the design of quantum controllers capable of maximizing the control yield and reaching the ultimate physical limit.

  10. Limits of optimal control yields achievable with quantum controllers

    NASA Astrophysics Data System (ADS)

    Wu, Re-Bing; Brif, Constantin; James, Matthew R.; Rabitz, Herschel

    2015-04-01

    In quantum optimal control theory, kinematic bounds are the minimum and maximum values of the control objective achievable for any physically realizable system dynamics. For a given initial state of the system, these bounds depend on the nature and state of the controller. We consider a general situation where the controlled quantum system is coupled to both an external classical field (referred to as a classical controller) and an auxiliary quantum system (referred to as a quantum controller). In this general situation, the kinematic bound is between the classical kinematic bound (CKB), corresponding to the case where only the classical controller is available, and the quantum kinematic bound (QKB), corresponding to the ultimate physical limit of the objective's value. Specifically, when the control objective is the expectation value of a quantum observable (a Hermitian operator on the system's Hilbert space), the QKBs are the minimum and maximum eigenvalues of this operator. We present, both qualitatively and quantitatively, the necessary and sufficient conditions for surpassing the CKB and reaching the QKB, through the use of a quantum controller. The general conditions are illustrated by examples in which the system and controller are initially in thermal states. The obtained results provide a basis for the design of quantum controllers capable of maximizing the control yield and reaching the ultimate physical limit.

  11. WFH: closing the global gap--achieving optimal care.

    PubMed

    Skinner, Mark W

    2012-07-01

    For 50 years, the World Federation of Hemophilia (WFH) has been working globally to close the gap in care and to achieve Treatment for All patients, men and women, with haemophilia and other inherited bleeding disorders, regardless of where they might live. The WFH estimates that more than one in 1000 men and women has a bleeding disorder equating to 6,900,000 worldwide. To close the gap in care between developed and developing nations a continued focus on the successful strategies deployed heretofore will be required. However, in response to the rapid advances in treatment and emerging therapeutic advances on the horizon it will also require fresh approaches and renewed strategic thinking. It is difficult to predict what each therapeutic advance on the horizon will mean for the future, but there is no doubt that we are in a golden age of research and development, which has the prospect of revolutionizing treatment once again. An improved understanding of "optimal" treatment is fundamental to the continued evolution of global care. The challenges of answering government and payer demands for evidence-based medicine, and cost justification for the introduction and enhancement of treatment, are ever-present and growing. To sustain and improve care it is critical to build the body of outcome data for individual patients, within haemophilia treatment centers (HTCs), nationally, regionally and globally. Emerging therapeutic advances (longer half-life therapies and gene transfer) should not be justified or brought to market based only on the notion that they will be economically more affordable, although that may be the case, but rather more importantly that they will be therapeutically more advantageous. Improvements in treatment adherence, reductions in bleeding frequency (including microhemorrhages), better management of trough levels, and improved health outcomes (including quality of life) should be the foremost considerations. As part of a new WFH strategic plan (2012-2014) the WFH has identified several key initiatives for particular emphasis - continuation of the Global Alliance for Progress (GAP) program, a new initiative to address underserved countries and regions (The Cornerstone Initiative), enhancing health outcomes research and analysis, and a new research mentorship program. Despite our progress to date in closing the global gap in care, our work is not complete. Too many patients remain undiagnosed and too few receive adequate treatment. This paper will also discuss historical, present and future challenges and opportunities to close the gap in care and achieve Treatment for All. PMID:22726075

  12. Optimal Taxation in Models of Endogenous Growth

    Microsoft Academic Search

    Larry E. Jones; Rodolfo E. Manuelli; Peter E. Rossi

    1993-01-01

    The authors study the problem of optimal taxation in three infinite-horizon, representative-agent endogenous growth models. The first model is a convex model in which physical and human capital are perfectly symmetric. The authors' second model incorporates elastic labor supply through a Lucas-style technology. Analysis of these two models points out the danger of assuming that government expenditures are exogenous. In

  13. Parental Involvement and Students' Academic Achievement: A Growth Modeling Analysis

    Microsoft Academic Search

    Xitao Fan

    2001-01-01

    The major research objective of this study was to assess the effect of parental involvement on students' academic growth during the high school years. The National Education Longitudinal Study of 1988 (NELS:88) data were used, and latent growth curve analysis within the framework of structural equation modeling was the major analytic tool. The following are the major findings of the

  14. Unconventional MBE Strategies from Computer Simulations for Optimized Growth Conditions

    E-print Network

    Biehl, Michael

    Unconventional MBE Strategies from Computer Simulations for Optimized Growth Conditions S. Schinzer MBE growth. The strategies are applicable in different growth regimes: During layer--by--layer growth high flux pulses of particles one can in­ crease the growth rate and assist layer--by--layer growth. If

  15. Growth and gaps in mathematics achievement of students with and without disabilities on a statewide achievement test.

    PubMed

    Stevens, Joseph J; Schulte, Ann C; Elliott, Stephen N; Nese, Joseph F T; Tindal, Gerald

    2015-02-01

    This study estimated mathematics achievement growth trajectories in a statewide sample of 92,045 students with and without disabilities over Grades 3 to 7. Students with disabilities (SWDs) were identified in seven exceptionality categories. Students without disabilities (SWoDs) were categorized as General Education (GE) or Academically/Intellectually Gifted (AIG). Students in all groups showed significant growth that decelerated over grades as well as significant variability in achievement by student group, both at the initial assessment in Grade 3 and in rates of growth over time. Race/ethnicity, gender, parental education, free/reduced lunch status, and English language proficiency were also significant predictors of achievement. Effect size estimates showed substantial year-to-year growth that decreased over grades. Sizeable achievement gaps that were relatively stable over grades were observed between SWoDs and students in specific exceptionality categories. Our study also demonstrated the importance of statistically controlling for variation related to student demographic characteristics. Additional research is needed that expands on these results with the same and additional exceptionality groups. PMID:25636260

  16. High-Achieving and Average Students' Reading Growth: Contrasting School and Summer Trajectories

    ERIC Educational Resources Information Center

    Rambo-Hernandez, Karen E.; McCoach, D. Betsy

    2015-01-01

    Much is unknown about how initially high-achieving students grow academically, especially given the measurement issues inherent in assessing growth for the highest performing students. This study compared initially high-achieving and average students' growth in reading (in a cohort of third-grade students from 2,000 schools) over 3 years.…

  17. Test Development with Performance Standards and Achievement Growth in Mind

    ERIC Educational Resources Information Center

    Ferrara, Steve; Svetina, Dubravka; Skucha, Sylvia; Davidson, Anne H.

    2011-01-01

    Items on test score scales located at and below the Proficient cut score define the content area knowledge and skills required to achieve proficiency. Alternately, examinees who perform at the Proficient level on a test can be expected to be able to demonstrate that they have mastered most of the knowledge and skills represented by the items at…

  18. A framework for optimization of crystal growth processes applied to VGF growth of fluorides

    NASA Astrophysics Data System (ADS)

    Backofen, Rainer; Voigt, Axel; Wulff-Molder, Dirk

    2005-02-01

    We develop a flexible framework for optimization of crystal growth processes. This framework is based on an accurate and robust process model and combines two optimization loops. Adapting of model parameters and optimizing of process parameters.

  19. Achieving Optimal Privacy in Trust-Aware Social Recommender Systems

    NASA Astrophysics Data System (ADS)

    Dokoohaki, Nima; Kaleli, Cihan; Polat, Huseyin; Matskin, Mihhail

    Collaborative filtering (CF) recommenders are subject to numerous shortcomings such as centralized processing, vulnerability to shilling attacks, and most important of all privacy. To overcome these obstacles, researchers proposed for utilization of interpersonal trust between users, to alleviate many of these crucial shortcomings. Till now, attention has been mainly paid to strong points about trust-aware recommenders such as alleviating profile sparsity or calculation cost efficiency, while least attention has been paid on investigating the notion of privacy surrounding the disclosure of individual ratings and most importantly protection of trust computation across social networks forming the backbone of these systems. To contribute to addressing problem of privacy in trust-aware recommenders, within this paper, first we introduce a framework for enabling privacy-preserving trust-aware recommendation generation. While trust mechanism aims at elevating recommender's accuracy, to preserve privacy, accuracy of the system needs to be decreased. Since within this context, privacy and accuracy are conflicting goals we show that a Pareto set can be found as an optimal setting for both privacy-preserving and trust-enabling mechanisms. We show that this Pareto set, when used as the configuration for measuring the accuracy of base collaborative filtering engine, yields an optimized tradeoff between conflicting goals of privacy and accuracy. We prove this concept along with applicability of our framework by experimenting with accuracy and privacy factors, and we show through experiment how such optimal set can be inferred.

  20. Achieving and documenting closure in plant growth facilities

    NASA Technical Reports Server (NTRS)

    Knott, W. M.; Sager, John C.; Wheeler, Ray

    1992-01-01

    As NASA proceeds with its effort to develop a Controlled Ecological Life Support System (CELSS) that will provide life support to crews during long duration space missions, it must address the question of facility and system closure. The concept of closure as it pertains to CELSS and engineering specifications, construction problems and monitoring procedures used in the development and operation of a closed plant growth facility for the CELSS program are described. A plant growth facility is one of several modules required for a CELSS. A prototype of this module at Kennedy Space Center is the large (7m tall x 3.5m diameter) Biomass Production Chamber (BPC), the central facility of the CELSS Breadboard Project. The BPC is atmospherically sealed to a leak rate of approximately 5 percent of its total volume per 24 hours. This paper will discuss the requirements for atmospheric closure in the facility, present CO2 and trace gas data from initial tests of the BPC with and without plants, and describe how the chamber was sealed atmospherically. Implications that research conducted in this type of facility will have for the CELSS program are discussed.

  1. PROMOTING OPTIMAL MONITORING OF CHILD GROWTH IN CANADA: USING THE NEW WHO GROWTH CHARTS

    Microsoft Academic Search

    2010-01-01

    Growth monitoring and promotion of optimal growth are essential components of primary health care for infants and children. Serial measurements of weight, height\\/length for all children, and head circumference for infants and toddlers, compared with the growth of a large sample population of children depicted on a selected growth chart help to confirm a child's healthy growth and development. It

  2. Multiphase Nano-Composite Coatings for Achieving Energy Optimization

    SciTech Connect

    Dr. Jose Nainaparampil

    2012-03-26

    UES Inc. and ANL teamed in this work to develop novel coating systems for the protection of surfaces from thermal degradation mainly in two applications; Machining and Die casting. These coatings were specifically designed for the purpose by incorporating required material phases and the overall architecture, which led to reduce the energy usage and increase efficiency of the operations. Following the UES/ANL'Â?s feasibility work, the coatings were developed utilizing High power impulse magnetron sputtering (HiPMS) and Large area filtered arc deposition (LAFAD) techniques. Toughness, hardness and oxidation resistance: contrasting qualities have been mixed in the right proportion to attain the suitable material characteristic for the cause. Hafnium diboride (HfB2) based materials provided such a system and its properties were tamed to attain the right combination of toughness and hardness by working on the microstructure and architecture of coatings. An effective interfacing material (graded concentrations of topcoat) was also achieved in this work to provide the required adhesion between the substrate and the coating. Combination of an appropriate bond coat and a functional top coat provided the present thermal degradation resistant coating for cutting tools and die-casting applications. Laboratory level performance tests and industrial level application tests by partner companies (Beta Site Testing) were used for the development of these coatings.

  3. Optimal Impedance Control for Task Achievement in the Presence of Signal-dependent Noise

    E-print Network

    Osu, Rieko

    Optimal Impedance Control for Task Achievement in the Presence of Signal-dependent Noise Rieko Osu1/60): Optimal Impedance Control with TOPS- Corresponding Author Mitsuo Kawato ATR Computational Neuroscience Laboratories 2-2-2 Hikaridai, Seika-cho, Soraku-gun Kyoto, 619-0288 Japan email: kawato@atr.jp TEL: +81

  4. Collective Responsibility, Academic Optimism, and Student Achievement in Taiwan Elementary Schools

    ERIC Educational Resources Information Center

    Wu, Hsin-Chieh

    2012-01-01

    Previous research indicates that collective efficacy, faculty trust in students and parents, and academic emphasis together formed a single latent school construct, called academic optimism. In the U.S., academic optimism has been proven to be a powerful construct that could effectively predict student achievement even after controlling for…

  5. The Effects of Academic Optimism on Student Academic Achievement in Alabama

    ERIC Educational Resources Information Center

    Bevel, Raymona King

    2010-01-01

    The purpose of the research was to determine the effects of academic optimism on student academic achievement through measuring the individual and collective effects of academic emphasis, collective efficacy, and faculty trust in clients. Data for this study were obtained from the School Academic Optimism Scale and the reading section of the…

  6. Parent Involvement and Science Achievement: A Cross-Classified Multilevel Latent Growth Curve Analysis

    ERIC Educational Resources Information Center

    Johnson, Ursula Y.; Hull, Darrell M.

    2014-01-01

    The authors examined science achievement growth at Grades 3, 5, and 8 and parent school involvement at the same time points using the Early Childhood Longitudinal Study-Kindergarten Class of 1998-1999. Data were analyzed using cross-classified multilevel latent growth curve modeling with time invariant and varying covariates. School-based…

  7. Cognitive Predictors of Achievement Growth in Mathematics: A 5Year Longitudinal Study

    Microsoft Academic Search

    David C. Geary

    2011-01-01

    The study's goal was to identify the beginning of 1st grade quantitative competencies that predict mathematics achievement start point and growth through 5th grade. Measures of number, counting, and arithmetic competencies were administered in early 1st grade and used to predict mathematics achievement through 5th (n = 177), while controlling for intelligence, working memory, and processing speed. Multilevel models revealed

  8. Promising Practices in Professional Growth & Support: "Case Study of Achievement First"

    ERIC Educational Resources Information Center

    Education Resource Strategies, 2013

    2013-01-01

    Four organizations with promising practices in teacher Professional Growth & Support have significantly raised outcomes for low-income students. The charter management networks, Achievement First and Aspire Public Schools, and the two reform organizations, Teach Plus and Agile Mind, have successfully increased student achievement with a…

  9. Growth in Standardized Ability and Achievement Test Scores From 3rd to 10th Grade

    Microsoft Academic Search

    Leslie Rescorla; Adena S. Rosenthal

    2004-01-01

    Growth in Test of Cognitive Skills (TCS) scores and Comprehensive Tests of Basic Skills (CTBS) reading, math, and total achievement scores from 3rd to 10th grade was studied in 328 public school students in a middle-class suburban community. Surprisingly, groups differing in ability and achievement in 3rd grade made parallel progress over time, and some \\

  10. Principal Leadership: Creating a Culture of Academic Optimism to Improve Achievement for All Students

    ERIC Educational Resources Information Center

    McGuigan, Leigh; Hoy, Wayne K.

    2006-01-01

    Since the Coleman Report (1966), educational researchers have tried to identify school properties that make a difference in student achievement and overcome the negative influence of low socioeconomic status. We theorized that academic optimism was a latent construct that enhanced student achievement and that enabling school structure provided a…

  11. Predictors of early growth in academic achievement: the head-toes-knees-shoulders task

    PubMed Central

    McClelland, Megan M.; Cameron, Claire E.; Duncan, Robert; Bowles, Ryan P.; Acock, Alan C.; Miao, Alicia; Pratt, Megan E.

    2014-01-01

    Children's behavioral self-regulation and executive function (EF; including attentional or cognitive flexibility, working memory, and inhibitory control) are strong predictors of academic achievement. The present study examined the psychometric properties of a measure of behavioral self-regulation called the Head-Toes-Knees-Shoulders (HTKS) by assessing construct validity, including relations to EF measures, and predictive validity to academic achievement growth between prekindergarten and kindergarten. In the fall and spring of prekindergarten and kindergarten, 208 children (51% enrolled in Head Start) were assessed on the HTKS, measures of cognitive flexibility, working memory (WM), and inhibitory control, and measures of emergent literacy, mathematics, and vocabulary. For construct validity, the HTKS was significantly related to cognitive flexibility, working memory, and inhibitory control in prekindergarten and kindergarten. For predictive validity in prekindergarten, a random effects model indicated that the HTKS significantly predicted growth in mathematics, whereas a cognitive flexibility task significantly predicted growth in mathematics and vocabulary. In kindergarten, the HTKS was the only measure to significantly predict growth in all academic outcomes. An alternative conservative analytical approach, a fixed effects analysis (FEA) model, also indicated that growth in both the HTKS and measures of EF significantly predicted growth in mathematics over four time points between prekindergarten and kindergarten. Results demonstrate that the HTKS involves cognitive flexibility, working memory, and inhibitory control, and is substantively implicated in early achievement, with the strongest relations found for growth in achievement during kindergarten and associations with emergent mathematics. PMID:25071619

  12. Optimal solutions for a free boundary problem for crystal growth

    E-print Network

    Seidman, Thomas I.

    Optimal solutions for a free boundary problem for crystal growth Pekka Neittaanm¨ aki Thomas I. Seidman Abstract. We consider a free boundary problem modeling the growth/dissolution of a crystal boundary problem corresponding to a model of growth (dissolution) of a radially symmetric crystal grain

  13. Achievement Goals and Achievement during Early Adolescence: Examining Time-Varying Predictor and Outcome Variables in Growth-Curve Analysis

    ERIC Educational Resources Information Center

    Shim, S. Serena; Ryan, Allison M.; Anderson, Carolyn J.

    2008-01-01

    The present study advances understanding of (a) the development of achievement goals, (b) the changing association of achievement goals and achievement over time, and (c) the implications of changes in achievement goals for changes in achievement over time. African American and European American adolescents' (N = 588) achievement goals and…

  14. Achieving optimal aesthetics for direct and indirect restorations with microhybrid composite resins.

    PubMed

    Okuda, Wynn H

    2005-04-01

    In aesthetic dentistry, material science has played a key role in the development of natural-appearing restorations. Despite the progress, there have been challenges in achieving a harmonious integration of direct and indirect posterior restorations. Although porcelain restorations provide natural aesthetics, ceramics cannot be applied via direct techniques. Consequently, composite resins are valuable alternatives for conservative posterior restorations. In addition, because of their differing physical and optical properties, optimal aesthetic blending with porcelain and resin cannot be routinely achieved. This article explores the potential of composite resins as a direct and indirect restorative option in achieving the most favorable natural blend in the posterior region. PMID:15974036

  15. Optimal Control for Degenerate Parabolic Equations with Logistic Growth*

    E-print Network

    ) of the population to be trapped is the control in our problem. We can treat zero Dirichlet (z = 0) or Neumann (noOptimal Control for Degenerate Parabolic Equations with Logistic Growth* by Suzanne M. Lenhart 1 and Jiongmin Yong 2 Abstract. This paper considers the optimal control of a degenerate parabolic partial dif

  16. Optimal Control for Degenerate Parabolic Equations with Logistic Growth*

    E-print Network

    (x;t) of the population to be trapped is the control in our problem. We can treat zero Dirichlet (z = 0) or Neumann(no uxOptimal Control for Degenerate Parabolic Equations with Logistic Growth* by Suzanne M. Lenhart1 and Jiongmin Yong2 Abstract. This paper considers the optimal control of a degenerate parabolic partial dif

  17. Optimal taxation and spending in general competitive growth models

    Microsoft Academic Search

    Kenneth L. Judd

    1999-01-01

    We find that the optimal long-run tax on capital income is zero even if the capital stock does not converge to a steady state nor to a steady state growth rate. The optimal tax on human capital is also zero if human capital is not a final good, but the long-run wage tax is not generally zero. We argue that

  18. Student Course Taking and Teacher Quality: Their Effects on Achievement and Growth

    ERIC Educational Resources Information Center

    Heck, Ronald H.; Mahoe, Rochelle

    2010-01-01

    Purpose: The purpose of this paper is to examine the relationship between high school students' curricular positions, their perceptions of the quality of their teachers, and school academic process variables on students' growth rates and ending achievement in mathematics and science. Design/methodology/approach: Multilevel latent curve modeling is…

  19. Academic Optimism, Organizational Citizenship Behaviors, and Student Achievement at Charter Schools

    ERIC Educational Resources Information Center

    Guvercin, Mustafa

    2013-01-01

    The purpose of this study was to examine the relationship among academic optimism, Organizational Citizenship Behaviors (OCBs), and student achievement in college preparatory charter schools. A purposeful sample of elementary school teachers from college preparatory charter schools (N = 226) in southeast Texas was solicited to complete the…

  20. Restricted and Repetitive Behaviors in Individuals with a History of ASDs Who Have Achieved Optimal Outcomes

    ERIC Educational Resources Information Center

    Troyb, Eva; Orinstein, Alyssa; Tyson, Katherine; Eigsti, Inge-Marie; Naigles, Letitia; Fein, Deborah

    2014-01-01

    Studies of autism spectrum disorders (ASDs) suggest that restricted and repetitive behaviors (RRBs) are particularly difficult to remediate. We examined present and past RRBs in 34 individuals who achieved optimal outcomes (OOs; lost their ASD diagnosis), 45 high-functioning individuals with ASD (HFA) and 34 typically developing (TD) peers. The OO…

  1. Precollege science achievement growth: Racial-ethnic and gender differences in cognitive and psychosocial constructs

    NASA Astrophysics Data System (ADS)

    Muller, Patricia Ann

    The purpose of this study was to gain a more complete understanding of the differences in science, mathematics and engineering education among racial-ethnic and gender subgroups by exploring factors related to precollege science achievement growth rates. Using Hierarchical Linear Modeling (HLM) and multi-wave, longitudinal data from the first three waves of the National Education Longitudinal Study of 1988--1994 (NELS:88/94), this study examined precollege science achievement growth rates during the 8th to 10th grade period and the 10th to 12th grade period for African American males, African American females, Latino males, Latina females, Asian American males, Asian American females, White males and White females. For the 8th--10th grade period, previous grades were significantly and positively related to science achievement growth for all subgroups; and socio-economic status and high school program were significantly and positively related to science achievement growth for all subgroups except one (Latino males, and Asian American males respectively). For the 10th--12th grade period, the quantity of science courses completed (science units) was the only variable that was statistically significant for more than one racial-ethnic by gender subgroup. Science units taken were significantly and positively related to 10 th--12th grade growth rates for all racial-ethnic by gender subgroups except Latino males. Locus-of-control was the only cognitive or psychosocial factor included from Eccles, Adler, Futterman, Goff, Kaczala, Meece and Midgley's (1983) theoretical framework for achievement behaviors that appeared to exhibit any pattern across race-ethnicities. Locus-of-control was positively related to 8th--10 th grade science achievement growth for females across all racial-ethnic subgroups, as well as for African American males. However, for both the 8 th--10th grade and 10th--12 th grade periods, there was no consistency across racial-ethnic or gender subgroups in effects of the remaining cognitive and psychosocial factors on science achievement growth rates. Cognitive and psychosocial variables were statistically significant only for specific subgroups, and did not generally exhibit any commonalities across gender, or by race. The findings accentuated the importance of disaggregating data and analyses by both race-ethnicity and gender.

  2. Microalgal growth with intracellular phosphorus for achieving high biomass growth rate and high lipid/triacylglycerol content simultaneously.

    PubMed

    Wu, Yin-Hu; Yu, Yin; Hu, Hong-Ying

    2015-09-01

    Nutrient deprivation is a commonly-used trigger for microalgal lipid accumulation, but its adverse impact on microalgal growth seems to be inevitable. In this study, Scenedesmus sp. LX1 was found to show similar physiological and biochemical variation under oligotrophic and eutrophic conditions during growth with intracellular phosphorus. Under both conditions microalgal chlorophyll content and photosynthesis activity was stable during this growth process, leading to significant increase of single cell weight and size. Therefore, while algal density growth rate dropped significantly to below 1.0×10(5)cellsmL(-1)d(-1) under oligotrophic condition, the biomass dry weight growth rate still maintained about 40mgL(-1)d(-1). Meanwhile, the lipid content in biomass and triacylglycerols (TAGs) content in lipids increased significantly to about 35% and 65%, respectively. Thus, high biomass growth rate and high lipid/TAG content were achieved simultaneously at the late growth phase with intracellular phosphorus. Besides, microalgal biomass produced was rich in carbohydrate with low protein content. PMID:26056779

  3. Influence of the Umbilical Cord Insertion Site on the Optimal Individual Birth Weight Achievement

    PubMed Central

    Dufour, Anaïs; Prot, Fabien; Feige, Jean-Jacques; Equy, Véronique; Alfaidy, Nadia; Gillois, Pierre; Hoffmann, Pascale

    2014-01-01

    Study Question. To determine whether the umbilical cord insertion site of singleton pregnancies could be linked to the newborn birth weight at term and its individual growth potential achievement. Material and Methods. A cohort study including 528 records of term neonates was performed. Each neonate was assessed for growth adjusted for gestational age according to the infant's growth potential using the AUDIPOG module. We considered two categories of umbilical cord insertions: central and peripheral. Intrauterine growth restriction was defined as birth weight below the 10th percentile. Statistical analysis was performed using Chi-square, Student's t test, Wilcoxon test, ANOVA, and logistic regression. Results. We observed a total of 343 centrally inserted cords versus 185 peripheral cords. There were twice as many smokers in the mothers of the peripheral category compared to the centrally inserted ones. More importantly, we demonstrated that only 17/343 (5.0%) of infants with central cord insertion were growth restricted, compared to 37/185 (20.0%) of the infants born with a peripheral insertion. Neonates with centrally inserted cord were significantly heavier. Conclusion. The umbilical cord insertion site of singleton pregnancies is associated with the newborn's birth weight at term and its individual growth potential achievement. PMID:24967357

  4. Fully localised nonlinear energy growth optimals in pipe flow

    NASA Astrophysics Data System (ADS)

    Pringle, Chris C. T.; Willis, Ashley P.; Kerswell, Rich R.

    2015-06-01

    A new, fully localised, energy growth optimal is found over large times and in long pipe domains at a given mass flow rate. This optimal emerges at a threshold disturbance energy below which a nonlinear version of the known (streamwise-independent) linear optimal [P. J. Schmid and D. S. Henningson, "Optimal energy density growth in Hagen-Poiseuille flow," J. Fluid Mech. 277, 192-225 (1994)] is selected and appears to remain the optimal up until the critical energy at which transition is triggered. The form of this optimal is similar to that found in short pipes [Pringle et al., "Minimal seeds for shear flow turbulence: Using nonlinear transient growth to touch the edge of chaos," J. Fluid Mech. 702, 415-443 (2012)], but now with full localisation in the streamwise direction. This fully localised optimal perturbation represents the best approximation yet of the minimal seed (the smallest perturbation which is arbitrarily close to states capable of triggering a turbulent episode) for "real" (laboratory) pipe flows. Dependence of the optimal with respect to several parameters has been computed and establishes that the structure is robust.

  5. Growth Optimal Investment Strategy Efficacy: An Application on Long Run Australian Equity Data

    Microsoft Academic Search

    Benjamin Francis Hunt

    2002-01-01

    A number of investment strategies designed to maximise portfolio growth are tested on a long run Australian equity data set. The application of these growth optimal portfolio techniques produces impressive rates of growth, despite the fact that the assumptions of normality and stability that underlie the growth optimal model are shown to be inconsistent with the data. Growth optimal portfolios

  6. Growth mixture modeling of academic achievement in children of varying birth weight risk.

    PubMed

    Espy, Kimberly Andrews; Fang, Hua; Charak, David; Minich, Nori; Taylor, H Gerry

    2009-07-01

    The extremes of birth weight and preterm birth are known to result in a host of adverse outcomes, yet studies to date largely have used cross-sectional designs and variable-centered methods to understand long-term sequelae. Growth mixture modeling (GMM) that utilizes an integrated person- and variable-centered approach was applied to identify latent classes of achievement from a cohort of school-age children born at varying birth weights. GMM analyses revealed 2 latent achievement classes for calculation, problem-solving, and decoding abilities. The classes differed substantively and persistently in proficiency and in growth trajectories. Birth weight was a robust predictor of class membership for the 2 mathematics achievement outcomes and a marginal predictor of class membership for decoding. Neither visuospatial-motor skills nor environmental risk at study entry added to class prediction for any of the achievement skills. Among children born preterm, neonatal medical variables predicted class membership uniquely beyond birth weight. More generally, GMM is useful in revealing coherence in the developmental patterns of academic achievement in children of varying weight at birth and is well suited to investigations of sources of heterogeneity. PMID:19586210

  7. Growth Mixture Modeling of Academic Achievement in Children of Varying Birth Weight Risk

    PubMed Central

    Espy, Kimberly Andrews; Fang, Hua; Charak, David; Minich, Nori; Taylor, H. Gerry

    2009-01-01

    The extremes of birth weight and preterm birth are known to result in a host of adverse outcomes, yet studies to date largely have used cross-sectional designs and variable-centered methods to understand long-term sequelae. Growth mixture modeling (GMM) that utilizes an integrated person- and variable-centered approach was applied to identify latent classes of achievement from a cohort of school-age children born at varying birth weights. GMM analyses revealed two latent achievement classes for calculation, problem-solving, and decoding abilities. The classes differed substantively and persistently in proficiency and in growth trajectories. Birth weight was a robust predictor of class membership for the two mathematics achievement outcomes and a marginal predictor of class membership for decoding. Neither visuospatial-motor skills nor environmental risk at study entry added to class prediction for any of the achievement skills. Among children born preterm, neonatal medical variables predicted class membership uniquely beyond birth weight. More generally, GMM is useful in revealing coherence in the developmental patterns of academic achievement in children of varying weight at birth, and is well suited to investigations of sources of heterogeneity. PMID:19586210

  8. Faculty Sense of Academic Optimism and Its Relationship to Students' Achievement in Well Performing High Schools

    ERIC Educational Resources Information Center

    Cromartie, Michael Tyrone

    2013-01-01

    The aim of this study was to determine the organizational characteristics and behaviors that contribute to sustaining a culture of academic optimism as a mechanism of student achievement. While there is a developing research base identifying both the individual elements of academic optimism as well as the academic optimism construct itself as…

  9. Optimization of Dairy Sludge for Growth of Rhizobium Cells

    PubMed Central

    Singh, Ashok Kumar; Singh, Gauri; Gautam, Digvijay; Bedi, Manjinder Kaur

    2013-01-01

    In this study dairy sludge was evaluated as an alternative cultivation medium for Rhizobium. Growth of bacterial strains at different concentrations of Dairy sludge was monitored. Maximum growth of all strains was observed at 60% Dairy sludge concentration. At 60% optical density (OD) values are 0.804 for Rhizobium trifolii (MTCC905), 0.825 for Rhizobium trifolii (MTCC906), and 0.793 for Rhizobium meliloti (MTCC100). Growth pattern of strains was observed at 60% Dairy sludge along with different synthetic media (tryptone yeast, Rhizobium minimal medium and yeast extract mannitol). Growth in 60% Dairy sludge was found to be superior to standard media used for Rhizobium. Media were optimized using 60% dairy sludge along with different concentrations of yeast extract (1–7?g/L) and mannitol (7–13?g/L) in terms of optical density at different time intervals, that is, 24, 48 and 72 hours. Maximum growth was observed in 6?g/L of yeast extract and 12?g/L of mannitol at 48-hour incubation period in all strains. The important environmental parameters such as pH were optimized using 60% dairy sludge, 60% dairy sludge +6?g/L yeast extract, and 60% dairy sludge +12?g/L mannitol. The maximum growth of all strains was found at pH 7.0. The present study recommends the use of 60% dairy sludge as a suitable growth medum for inoculant production. PMID:24089690

  10. Optimal capacity in the Banking Sector and Economic Growth

    E-print Network

    Paris-Sud XI, Université de

    Optimal capacity in the Banking Sector and Economic Growth Bruno AMABLE Jean-Bernard CHATELAIN Olivier DE BANDT§ PostPrint, published in: Journal of Banking and Finance, 2002, 26, pp.491-517. Abstract capacity of the banking system. For that purpose, we consider an overlapping generation model

  11. OPTIMAL GROWTH AND SECONDARY METABOLITE PRODUCTION FROM COTTON HAIRY ROOTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hairy root cultures are an ideal system to investigate metabolite production and regulation in cotton. As part of our studies on cotton hairy root cultures, experiments were conducted to optimize culture growth rate and secondary metabolite production. In addition to gossypol (a disesquiterpene with...

  12. Relating optimal growth to counterpropagating Rossby waves in shear instability

    E-print Network

    Hoskins, Brian

    Relating optimal growth to counterpropagating Rossby waves in shear instability Eyal Heifetza of components called counterpropagating Rossby waves CRWs . Pairs of CRWs were originally used by Bretherton of the other CRW, thus advecting the mean PV. Although a single Rossby wave is neutral, their interaction can

  13. The MBE growth and optimization of high performance terahertz frequency quantum cascade lasers.

    PubMed

    Li, L H; Zhu, J X; Chen, L; Davies, A G; Linfield, E H

    2015-02-01

    The technique of molecular beam epitaxy has recently been used to demonstrate the growth of terahertz frequency GaAs/AlGaAs quantum cascade lasers (QCL) with Watt-level optical output powers. In this paper, we discuss the critical importance of achieving accurate layer thicknesses and alloy compositions during growth, and demonstrate that precise growth control as well as run-to-run growth reproducibility is possible. We also discuss the importance of minimizing background doping level in maximizing QCL performance. By selecting high-performance active region designs, and optimizing the injection doping level and device fabrication, we demonstrate total optical (two-facet) output powers as high as 1.56 W. PMID:25836134

  14. Transmitter Optimization for Achieving Secrecy Capacity in Gaussian MIMO Wiretap Channels

    E-print Network

    Li, Jiangyuan

    2009-01-01

    We consider a Gaussian multiple-input multiple-output (MIMO) wiretap channel model, where there exists a transmitter, a legitimate receiver and an eavesdropper, each node equipped with multiple antennas. We study the problem of finding the optimal input covariance matrix that achieves secrecy capacity subject to a power constraint, which leads to a non-convex optimization problem that is in general difficult to solve. Existing results for this problem address the case in which the transmitter and the legitimate receiver have two antennas each and the eavesdropper has one antenna. For the general cases, it has been shown that the optimal input covariance matrix has low rank when the difference between the Grams of the eavesdropper and the legitimate receiver channel matrices is indefinite or semi-definite, while it may have low rank or full rank when the difference is positive definite. In this paper, the aforementioned non-convex optimization problem is investigated. In particular, for the multiple-input sing...

  15. How to Achieve the Optimal DMT of Selective Fading MIMO Channels?

    E-print Network

    Mroueh, Lina

    2010-01-01

    In this paper, we consider a particular class of selective fading channel corresponding to a channel that is selective either in time or in frequency. For this class of channel, we propose a systematic way to achieve the optimal DMT derived in Coronel and B\\"olcskei, IEEE ISIT, 2007 by extending the non-vanishing determinant (NVD) criterion to the selective channel case. A new code construction based on split NVD parallel codes is then proposed to satisfy the NVD parallel criterion. This result is of significant interest not only in its own right, but also because it settles a long-standing debate in the literature related to the optimal DMT of selective fading channels.

  16. Perceived social support and academic achievement: cross-lagged panel and bivariate growth curve analyses.

    PubMed

    Mackinnon, Sean P

    2012-04-01

    As students transition to post-secondary education, they experience considerable stress and declines in academic performance. Perceived social support is thought to improve academic achievement by reducing stress. Longitudinal designs with three or more waves are needed in this area because they permit stronger causal inferences and help disentangle the direction of relationships. This study uses a cross-lagged panel and a bivariate growth curve analysis with a three-wave longitudinal design. Participants include 10,445 students (56% female; 12.6% born outside of Canada) transitioning to post-secondary education from ages 15-19. Self-report measures of academic achievement and a generalized measure of perceived social support were used. An increase in average relative standing in academic achievement predicted an increase in average relative standing on perceived social support 2 years later, but the reverse was not true. High levels of perceived social support at age 15 did not protect against declines in academic achievement over time. In sum, perceived social support appears to have no bearing on adolescents' future academic performance, despite commonly held assumptions of its importance. PMID:21720859

  17. The controlled growth method - A tool for structural optimization

    NASA Technical Reports Server (NTRS)

    Hajela, P.; Sobieszczanski-Sobieski, J.

    1981-01-01

    An adaptive design variable linking scheme in a NLP based optimization algorithm is proposed and evaluated for feasibility of application. The present scheme, based on an intuitive effectiveness measure for each variable, differs from existing methodology in that a single dominant variable controls the growth of all others in a prescribed optimization cycle. The proposed method is implemented for truss assemblies and a wing box structure for stress, displacement and frequency constraints. Substantial reduction in computational time, even more so for structures under multiple load conditions, coupled with a minimal accompanying loss in accuracy, vindicates the algorithm.

  18. Numerical Optimization of the Thermal Field in Bridgman Detached Growth

    NASA Technical Reports Server (NTRS)

    Stelian, C.; Volz, M. P.; Derby, J. J.

    2009-01-01

    The global modeling of the thermal field in two vertical Bridgman-like crystal growth configurations, has been performed to get optimal thermal conditions for a successful detached growth of Ge and CdTe crystals. These computations are performed using the CrysMAS code and expand upon our previous analysis [1] that propose a new mechanism involving the thermal field and meniscus position to explain stable conditions for dewetted Bridgman growth. The analysis of the vertical Bridgman configuration with two heaters, used by Palosz et al. for the detached growth of Ge, shows, consistent with their results, that the large wetting angle of germanium on boron nitride surfaces was an important factor to promote a successful detached growth. Our computations predict that by initiating growth much higher into the hot zone of the furnace, the thermal conditions will be favorable for continued detachment even for systems that did not exhibit high contact angles. The computations performed for a vertical gradient freeze configuration with three heaters representative of that used for the detached growth of CdTe, show favorable thermal conditions for dewetting during the entirely growth run described. Improved thermal conditions are also predicted for coated silica crucibles when the solid-liquid interface advances higher into the hot zone during the solidification process. The second set of experiments on CdTe growth described elsewhere has shown the reattachment of the crystal to the crucible after few centimeters of dewetted growth. The thermal modeling of this configuration shows a second solidification front appearing at the top of the sample and approaching the middle line across the third heater. In these conditions, the crystal grows detached from the bottom, but will be attached to the crucible in the upper part because of the solidification without gap in this region. The solidification with two interfaces can be avoided when the top of the sample is positioned below the middle position of the third furnace.

  19. Journal of Crystal Growth 280 (2005) 587593 Optimization of the mineral content in polymeric gels

    E-print Network

    Azad, Abdul-Majeed

    2005-01-01

    Journal of Crystal Growth 280 (2005) 587­593 Optimization of the mineral content in polymeric gels that the optimal growth of hydroxyapatite crystals will take place at the stoichiometric Ca/P molar ratio of 1 other than the formation and growth of hydroxyapatite crystals. Therefore, the optimal level

  20. Hierarchically structured hematite architectures achieved by growth in a silica hydrogel.

    PubMed

    Asenath-Smith, Emily; Hovden, Robert; Kourkoutis, Lena F; Estroff, Lara A

    2015-04-22

    Biomineralization strategies include the use of hydrogels to direct the formation of composite, single-crystal-like structures with unique structure-property profiles. Application of similar synthetic approaches to transition-metal oxides has the promise to yield low-temperature routes to hierarchically structured crystals that are optimized for a range of applications. Here, growth of hematite (?-Fe2O3) within a silica hydrogel resulted in hierarchical, mosaic crystals preferentially expressing catalytically active {110} facets, which are absent in solution-grown controls. Quantitative structural and compositional analysis reveals architectural changes that begin with the incorporation of silicon into the hematite lattice and propagate through to the nanoscale domain structure and assembly, leading to microscale morphologies that show improved photocatalytic performance. This work demonstrates the potential of applying bioinspired crystallization techniques to design functional oxides with multiscale architectural features. PMID:25822466

  1. CCMR: Growth Parameter Optimization and Contact Printing of Germanium Nanowires

    NSDL National Science Digital Library

    Blood-Forsythe, Martin A.

    2008-08-15

    Germanium nanowires, grown by gold nanoparticle catalyzed chemical vapor deposition, are highly promissing building blocks for future electronic devices and are versatile components for a variety of optoelectronic studies. This project seeks to further optimize the growth paramenters for a variety of diameter nanowires and by use of contact printing and sonication, transfer these wires as an aligned array and a suspended solution of nanowires, for use in a THz probe spectroscopy study and a quantitative electron energy loss microscopy study.

  2. Effects of Schoolwide Cluster Grouping and within-Class Ability Grouping on Elementary School Students' Academic Achievement Growth

    ERIC Educational Resources Information Center

    Matthews, Michael S.; Ritchotte, Jennifer A.; McBee, Matthew T.

    2013-01-01

    We evaluated the effects of one year of schoolwide cluster grouping on the academic achievement growth of gifted and non-identified elementary students using a piecewise multilevel growth model. Scores from 186 non-identified and 68 gifted students' Measures of Academic Progress Reading and Math scores were examined over three school years.…

  3. Achieving conservation when opportunity costs are high: optimizing reserve design in Alberta's oil sands region.

    PubMed

    Schneider, Richard R; Hauer, Grant; Farr, Dan; Adamowicz, W L; Boutin, Stan

    2011-01-01

    Recent studies have shown that conservation gains can be achieved when the spatial distributions of biological benefits and economic costs are incorporated in the conservation planning process. Using Alberta, Canada, as a case study we apply these techniques in the context of coarse-filter reserve design. Because targets for ecosystem representation and other coarse-filter design elements are difficult to define objectively we use a trade-off analysis to systematically explore the relationship between conservation targets and economic opportunity costs. We use the Marxan conservation planning software to generate reserve designs at each level of conservation target to ensure that our quantification of conservation and economic outcomes represents the optimal allocation of resources in each case. Opportunity cost is most affected by the ecological representation target and this relationship is nonlinear. Although petroleum resources are present throughout most of Alberta, and include highly valuable oil sands deposits, our analysis indicates that over 30% of public lands could be protected while maintaining access to more than 97% of the value of the region's resources. Our case study demonstrates that optimal resource allocation can be usefully employed to support strategic decision making in the context of land-use planning, even when conservation targets are not well defined. PMID:21858046

  4. Achieving Conservation when Opportunity Costs Are High: Optimizing Reserve Design in Alberta's Oil Sands Region

    PubMed Central

    Schneider, Richard R.; Hauer, Grant; Farr, Dan; Adamowicz, W. L.; Boutin, Stan

    2011-01-01

    Recent studies have shown that conservation gains can be achieved when the spatial distributions of biological benefits and economic costs are incorporated in the conservation planning process. Using Alberta, Canada, as a case study we apply these techniques in the context of coarse-filter reserve design. Because targets for ecosystem representation and other coarse-filter design elements are difficult to define objectively we use a trade-off analysis to systematically explore the relationship between conservation targets and economic opportunity costs. We use the Marxan conservation planning software to generate reserve designs at each level of conservation target to ensure that our quantification of conservation and economic outcomes represents the optimal allocation of resources in each case. Opportunity cost is most affected by the ecological representation target and this relationship is nonlinear. Although petroleum resources are present throughout most of Alberta, and include highly valuable oil sands deposits, our analysis indicates that over 30% of public lands could be protected while maintaining access to more than 97% of the value of the region's resources. Our case study demonstrates that optimal resource allocation can be usefully employed to support strategic decision making in the context of land-use planning, even when conservation targets are not well defined. PMID:21858046

  5. Academic abilities in children and adolescents with a history of autism spectrum disorders who have achieved optimal outcomes.

    PubMed

    Troyb, Eva; Orinstein, Alyssa; Tyson, Katherine; Helt, Molly; Eigsti, Inge-Marie; Stevens, Michael; Fein, Deborah

    2014-04-01

    This study examines the academic abilities of children and adolescents who were once diagnosed with an autism spectrum disorder, but who no longer meet diagnostic criteria for this disorder. These individuals have achieved social and language skills within the average range for their ages, receive little or no school support, and are referred to as having achieved "optimal outcomes." Performance of 32 individuals who achieved optimal outcomes, 41 high-functioning individuals with a current autism spectrum disorder diagnosis (high-functioning autism), and 34 typically developing peers was compared on measures of decoding, reading comprehension, mathematical problem solving, and written expression. Groups were matched on age, sex, and nonverbal IQ; however, the high-functioning autism group scored significantly lower than the optimal outcome and typically developing groups on verbal IQ. All three groups performed in the average range on all subtests measured, and no significant differences were found in performance of the optimal outcome and typically developing groups. The high-functioning autism group scored significantly lower on subtests of reading comprehension and mathematical problem solving than the optimal outcome group. These findings suggest that the academic abilities of individuals who achieved optimal outcomes are similar to those of their typically developing peers, even in areas where individuals who have retained their autism spectrum disorder diagnoses exhibit some ongoing difficulty. PMID:24096312

  6. Legionella pneumophila requires polyamines for optimal intracellular growth.

    PubMed

    Nasrallah, Gheyath K; Riveroll, Angela L; Chong, Audrey; Murray, Lois E; Lewis, P Jeffrey; Garduño, Rafael A

    2011-09-01

    The Gram-negative intracellular pathogen Legionella pneumophila replicates in a membrane-bound compartment known as the Legionella-containing vacuole (LCV), into which it abundantly releases its chaperonin, HtpB. To determine whether HtpB remains within the LCV or reaches the host cell cytoplasm, we infected U937 human macrophages and CHO cells with L. pneumophila expressing a translocation reporter consisting of the Bordetella pertussisa denylate cyclase fused to HtpB. These infections led to increased cyclic AMP levels, suggesting that HtpB reaches the host cell cytoplasm. To identify potential functions of cytoplasmic HtpB, we expressed it in the yeast Saccharomyces cerevisiae, where HtpB induced pseudohyphal growth. A yeast-two-hybrid screen showed that HtpB interacted with S-adenosylmethionine decarboxylase (SAMDC), an essential yeast enzyme (encoded by SPE2) that is required for polyamine biosynthesis. Increasing the copy number of SPE2 induced pseudohyphal growth in S. cerevisiae; thus, we speculated that (i) HtpB induces pseudohyphal growth by activating polyamine synthesis and (ii) L. pneumophila may require exogenous polyamines for growth. A pharmacological inhibitor of SAMDC significantly reduced L. pneumophila replication in L929 mouse cells and U937 macrophages, whereas exogenously added polyamines moderately favored intracellular growth, confirming that polyamines and host SAMDC activity promote L. pneumophila proliferation. Bioinformatic analysis revealed that most known enzymes required for polyamine biosynthesis in bacteria (including SAMDC) are absent in L. pneumophila, further suggesting a need for exogenous polyamines. We hypothesize that HtpB may function to ensure a supply of polyamines in host cells, which are required for the optimal intracellular growth of L. pneumophila. PMID:21742865

  7. Legionella pneumophilaRequires Polyamines for Optimal Intracellular Growth ?

    PubMed Central

    Nasrallah, Gheyath K.; Riveroll, Angela L.; Chong, Audrey; Murray, Lois E.; Lewis, P. Jeffrey; Garduño, Rafael A.

    2011-01-01

    The Gram-negative intracellular pathogen Legionella pneumophilareplicates in a membrane-bound compartment known as the Legionella-containing vacuole (LCV), into which it abundantly releases its chaperonin, HtpB. To determine whether HtpB remains within the LCV or reaches the host cell cytoplasm, we infected U937 human macrophages and CHO cells with L. pneumophilaexpressing a translocation reporter consisting of the Bordetella pertussisadenylate cyclase fused to HtpB. These infections led to increased cyclic AMP levels, suggesting that HtpB reaches the host cell cytoplasm. To identify potential functions of cytoplasmic HtpB, we expressed it in the yeast Saccharomyces cerevisiae, where HtpB induced pseudohyphal growth. A yeast-two-hybrid screen showed that HtpB interacted with S-adenosylmethionine decarboxylase (SAMDC), an essential yeast enzyme (encoded by SPE2) that is required for polyamine biosynthesis. Increasing the copy number of SPE2induced pseudohyphal growth in S. cerevisiae; thus, we speculated that (i) HtpB induces pseudohyphal growth by activating polyamine synthesis and (ii) L. pneumophilamay require exogenous polyamines for growth. A pharmacological inhibitor of SAMDC significantly reduced L. pneumophilareplication in L929 mouse cells and U937 macrophages, whereas exogenously added polyamines moderately favored intracellular growth, confirming that polyamines and host SAMDC activity promote L. pneumophilaproliferation. Bioinformatic analysis revealed that most known enzymes required for polyamine biosynthesis in bacteria (including SAMDC) are absent in L. pneumophila, further suggesting a need for exogenous polyamines. We hypothesize that HtpB may function to ensure a supply of polyamines in host cells, which are required for the optimal intracellular growth of L. pneumophila. PMID:21742865

  8. Understanding the mathematics and science achievement and growth trajectories of high ability high school students using hierarchical linear modeling

    NASA Astrophysics Data System (ADS)

    Belen-Ferrer, Bellasanta

    2009-12-01

    This study used longitudinal data and individual, family, and academic-related matriculation variables to examine trends in initial status and growth trajectories in overall academics, mathematics, and science achievement among 224 high ability high school Asian students. Results indicate that females have an advantage in both initial status and growth rates in overall academics and science. None of the family variables entered in the models were found to be significantly related to overall academics grade point average. All available matriculation variables entered into the models explained less than or at most about half the variance in initial achievement status and growth rate in overall academics and science but not in mathematics. These results strongly imply that other factors, notably family and school and/or classroom-related variables, not measured by the ones used in the models could explain the expected variance in initial status and growth rate of the students especially in Mathematics.

  9. Growth Trajectories of Mathematics Achievement: Longitudinal Tracking of Student Academic Progress

    ERIC Educational Resources Information Center

    Mok, Magdalena M. C.; McInerney, Dennis M.; Zhu, Jinxin; Or, Anthony

    2015-01-01

    Background: A number of methods to investigate growth have been reported in the literature, including hierarchical linear modelling (HLM), latent growth modelling (LGM), and multidimensional scaling applied to longitudinal profile analysis (LPAMS). Aims: This study aimed at modelling the mathematics growth of students over a span of 6 years from…

  10. Optimization of cell growth and poly(3-hydroxybutyrate) accumulation on date syrup by a Bacillus megaterium strain

    Microsoft Academic Search

    S. Omar; A. Rayes; A. Eqaab; I. Voß; A. Steinbüchel

    2001-01-01

    Optimal growth and PHB accumulation in Bacillus megaterium occurred with 5% (w\\/v) date syrup or beet molasses supplemented with NH4Cl. When date syrup and beet molasses were used alone without an additional nitrogen source, a cell density of about 3gl-1 with a PHB content of the cells of 50% (w\\/w) was achieved. NH4NO3 followed by ammonium acetate and then NH4Cl

  11. Plasticity in the growth of the chick eye: Emmetropization achieved by alternate morphologies.

    PubMed

    Wahl, Christina; Li, Tong; Howland, Howard

    2015-05-01

    Both refractive properties of the eyes and ambient light conditions affect emmetropization during growth. Exposure to constant light flattens the cornea making chicks hyperopic. To discover whether and how growing chick eyes restore emmetropia after exposure to constant light (CL) for 3, 7, or 11weeks, we returned chicks to normal (N) conditions with 12h. of light alternating with 12h. of darkness (designated the "R", or recovery, condition) for total periods of 4, 7, 11, or 17weeks. The two control groups were raised in CL conditions or raised in N conditions for the same length of time. We measured anterior chamber depths and lens thicknesses with an A-scan ultrasound machine. We measured corneal curvatures with an eight-axis keratometer, and refractions with conventional retinoscopy. We estimated differences in optical powers of CL, R and N chicks of identical age by constructing ray-tracing models using the above measurements and age-adjusted normal lens curvatures. We also computed the sensitivity of focus for small perturbations of the above optical parameters. Full refractive recovery from CL effects always occurred. Hyperopic refractive errors were absent when R chicks were returned to N for as little as 1week after 3weeks CL treatment. In R chicks exposed to CL for 11weeks and returned to N, axial lengths, vitreous chamber depths and radii of corneal curvatures did not return to normal, although their refractions did. While R chicks can usually recover emmetropia, after long periods of exposure to CL, they cannot recover normal ocular morphology. Emmetropization following CL exposure is achieved primarily by adjusting the relationship between corneal curvature and axial length, resulting in normal refractions. PMID:25765992

  12. A study of the relationships between distributed leadership, teacher academic optimism and student achievement in Taiwanese elementary schools

    Microsoft Academic Search

    I-Hua Chang

    2011-01-01

    The purpose of this study was to explore the relationships between distributed leadership, teachers’ academic optimism and student achievement in learning. The study targeted public elementary schools in Taiwan and adopted stratified random sampling to investigate 1500 teachers. Teachers’ perceptions were collected by a self-report scale. In addition to using descriptive statistics and an analysis of variance to examine teachers’

  13. A Study of the Relationships between Distributed Leadership, Teacher Academic Optimism and Student Achievement in Taiwanese Elementary Schools

    ERIC Educational Resources Information Center

    Chang, I-Hua

    2011-01-01

    The purpose of this study was to explore the relationships between distributed leadership, teachers' academic optimism and student achievement in learning. The study targeted public elementary schools in Taiwan and adopted stratified random sampling to investigate 1500 teachers. Teachers' perceptions were collected by a self-report scale. In…

  14. Applying thermodynamics constraints to the model achieves higher growth rates and flux efficiency while still adhering to

    E-print Network

    Barthelat, Francois

    -added biomateri- als from wastewater (bioplastics and biofuels) Genome-scale metabolic model of Rhodococcus jostii· Applying thermodynamics constraints to the model achieves higher growth rates and flux efficiencyGill University SIGNIFICANCE RESULTS (Normalized fluxes) CONCLUSION METHODOLOGY Metabolic Model (Stoichiometric

  15. An efficient framework for optimization and parameter sensitivity analysis in arterial growth and remodeling computations

    PubMed Central

    Sankaran, Sethuraman; Humphrey, Jay D.; Marsden, Alison L.

    2013-01-01

    Computational models for vascular growth and remodeling (G&R) are used to predict the long-term response of vessels to changes in pressure, flow, and other mechanical loading conditions. Accurate predictions of these responses are essential for understanding numerous disease processes. Such models require reliable inputs of numerous parameters, including material properties and growth rates, which are often experimentally derived, and inherently uncertain. While earlier methods have used a brute force approach, systematic uncertainty quantification in G&R models promises to provide much better information. In this work, we introduce an efficient framework for uncertainty quantification and optimal parameter selection, and illustrate it via several examples. First, an adaptive sparse grid stochastic collocation scheme is implemented in an established G&R solver to quantify parameter sensitivities, and near-linear scaling with the number of parameters is demonstrated. This non-intrusive and parallelizable algorithm is compared with standard sampling algorithms such as Monte-Carlo. Second, we determine optimal arterial wall material properties by applying robust optimization. We couple the G&R simulator with an adaptive sparse grid collocation approach and a derivative-free optimization algorithm. We show that an artery can achieve optimal homeostatic conditions over a range of alterations in pressure and flow; robustness of the solution is enforced by including uncertainty in loading conditions in the objective function. We then show that homeostatic intramural and wall shear stress is maintained for a wide range of material properties, though the time it takes to achieve this state varies. We also show that the intramural stress is robust and lies within 5% of its mean value for realistic variability of the material parameters. We observe that prestretch of elastin and collagen are most critical to maintaining homeostasis, while values of the material properties are most critical in determining response time. Finally, we outline several challenges to the G&R community for future work. We suggest that these tools provide the first systematic and efficient framework to quantify uncertainties and optimally identify G&R model parameters. PMID:23626380

  16. Layered Plant-Growth Media for Optimizing Gaseous, Liquid and Nutrient Requirements: Modeling, Design and Monitoring

    NASA Astrophysics Data System (ADS)

    Heinse, R.; Jones, S. B.; Bingham, G.; Bugbee, B.

    2006-12-01

    Rigorous management of restricted root zones utilizing coarse-textured porous media greatly benefits from optimizing the gas-water balance within plant-growth media. Geophysical techniques can help to quantify root- zone parameters like water content, air-filled porosity, temperature and nutrient concentration to better address the root systems performance. The efficiency of plant growth amid high root densities and limited volumes is critically linked to maintaining a favorable water content/air-filled porosity balance while considering adequate fluxes to replenish water at decreasing hydraulic conductivities during uptake. Volumes adjacent to roots also need to be optimized to provide adequate nutrients throughout the plant's life cycle while avoiding excessive salt concentrations. Our objectives were to (1) design and model an optimized root zone system using optimized porous media layers, (2) verify our design by monitoring the water content distribution and tracking nutrient release and transport, and (3) mimic water and nutrient uptake using plants or wicks to draw water from the root system. We developed a unique root-zone system using layered Ottawa sands promoting vertically uniform water contents and air-filled porosities. Watering was achieved by maintaining a shallow saturated layer at the bottom of the column and allowing capillarity to draw water upward, where coarser particle sizes formed the bottom layers with finer particles sizes forming the layers above. The depth of each layer was designed to optimize water content based on measurements and modeling of the wetting water retention curves. Layer boundaries were chosen to retain saturation between 50 and 85 percent. The saturation distribution was verified by dual-probe heat-pulse water-content sensors. The nutrient experiment involved embedding slow release fertilizer in the porous media in order to detect variations in electrical resistivity versus time during the release, diffusion and uptake of nutrients. The experiment required a specific geometry for the acquisition of ERT data using the heat-pulse water-content sensor's steel needles as electrodes. ERT data were analyzed using the sensed water contents and deriving pore-water resistivities using Archie's law. This design should provide a more optimal root-zone environment by maintaining a more uniform water content and on-demand supply of water than designs with one particle size at all column heights. The monitoring capability offers an effective means to describe the relationship between root-system performance and plant growth.

  17. Growth or Reproduction: Emergence of an Evolutionary Optimal Strategy

    E-print Network

    Grilli, Jacopo; Maritan, Amos

    2013-01-01

    Modern ecology has re-emphasized the need for a quantitative understanding of the original 'survival of the fittest theme' based on analyzis of the intricate trade-offs between competing evolutionary strategies that characterize the evolution of life. This is key to the understanding of species coexistence and ecosystem diversity under the omnipresent constraint of limited resources. In this work we propose an agent based model replicating a community of interacting individuals, e.g. plants in a forest, where all are competing for the same finite amount of resources and each competitor is characterized by a specific growth-reproduction strategy. We show that such an evolution dynamics drives the system towards a stationary state characterized by an emergent optimal strategy, which in turn depends on the amount of available resources the ecosystem can rely on. We find that the share of resources used by individuals is power-law distributed with an exponent directly related to the optimal strategy. The model ca...

  18. The Impact of SMART Board Technology on Growth in Mathematics Achievement of Gifted Learners

    ERIC Educational Resources Information Center

    Riska, Patricia A.

    2010-01-01

    This study examined whether SMART Board technology increased growth in mathematics performance of fourth grade gifted students. Gifted students in North Carolina were studied to determine if the use of SMART Board technology during mathematics instruction impacted their growth on standardized state tests. The sample consisted of 175 students from…

  19. Using Above-Level Testing to Track Growth in Academic Achievement in Gifted Students

    ERIC Educational Resources Information Center

    Warne, Russell T.

    2014-01-01

    Above-level testing is the practice of administering aptitude or academic achievement tests that are designed for typical students in higher grades or older age-groups to gifted or high-achieving students. Although widely accepted in gifted education, above-level testing has not been subject to careful psychometric scrutiny. In this study, I…

  20. Achieving Optimality and Fairness in Autonomous Demand Response: Benchmarks and Billing Mechanisms

    E-print Network

    Mohsenian-Rad, Hamed

    the utility remotely controls energy consumption for certain high-load household appliances such as air-conditioners to their contributions in achieving the overall system's design objectives. Similarly, they do not address the important. In this paper, we seek to tackle these shortcomings and design new autonomous DR systems that can achieve both

  1. Modeling urban growth by the use of a multiobjective optimization approach: environmental and economic issues for the Yangtze watershed, China.

    PubMed

    Zhang, Wenting; Wang, Haijun; Han, Fengxiang; Gao, Juan; Nguyen, Thuminh; Chen, Yarong; Huang, Bo; Zhan, F Benjamin; Zhou, Lequn; Hong, Song

    2014-11-01

    Urban growth is an unavoidable process caused by economic development and population growth. Traditional urban growth models represent the future urban growth pattern by repeating the historical urban growth regulations, which can lead to a lot of environmental problems. The Yangtze watershed is the largest and the most prosperous economic area in China, and it has been suffering from rapid urban growth from the 1970s. With the built-up area increasing from 23,238 to 31,054 km(2) during the period from 1980 to 2005, the watershed has suffered from serious nonpoint source (NPS) pollution problems, which have been mainly caused by the rapid urban growth. To protect the environment and at the same time maintain the economic development, a multiobjective optimization (MOP) is proposed to tradeoff the multiple objectives during the urban growth process of the Yangtze watershed. In particular, the four objectives of minimization of NPS pollution, maximization of GDP value, minimization of the spatial incompatibility between the land uses, and minimization of the cost of land-use change are considered by the MOP approach. Conventionally, a genetic algorithm (GA) is employed to search the Pareto solution set. In our MOP approach, a two-dimensional GA, rather than the traditional one-dimensional GA, is employed to assist with the search for the spatial optimization solution, where the land-use cells in the two-dimensional space act as genes in the GA. Furthermore, to confirm the superiority of the MOP approach over the traditional prediction approaches, a widely used urban growth prediction model, cellular automata (CA), is also carried out to allow a comparison with the Pareto solution of MOP. The results indicate that the MOP approach can make a tradeoff between the multiple objectives and can achieve an optimal urban growth pattern for Yangtze watershed, while the CA prediction model just represents the historical urban growth pattern as the future growth pattern. Moreover, according to the spatial clustering index, the urban growth pattern predicted through MOP is more reasonable. In summary, the proposed model provides a set of Pareto urban growth solutions, which compromise environmental and economic issues for the Yangtze watershed. PMID:24994100

  2. Optimization of pulsed laser deposited ZnO thin-film growth parameters for thin-film transistors (TFT) application

    NASA Astrophysics Data System (ADS)

    Gupta, Manisha; Chowdhury, Fatema Rezwana; Barlage, Douglas; Tsui, Ying Yin

    2013-03-01

    In this work we present the optimization of zinc oxide (ZnO) film properties for a thin-film transistor (TFT) application. Thin films, 50±10 nm, of ZnO were deposited by Pulsed Laser Deposition (PLD) under a variety of growth conditions. The oxygen pressure, laser fluence, substrate temperature and annealing conditions were varied as a part of this study. Mobility and carrier concentration were the focus of the optimization. While room-temperature ZnO growths followed by air and oxygen annealing showed improvement in the (002) phase formation with a carrier concentration in the order of 1017-1018/cm3 with low mobility in the range of 0.01-0.1 cm2/V s, a Hall mobility of 8 cm2/V s and a carrier concentration of 5×1014/cm3 have been achieved on a relatively low temperature growth (250 °C) of ZnO. The low carrier concentration indicates that the number of defects have been reduced by a magnitude of nearly a 1000 as compared to the room-temperature annealed growths. Also, it was very clearly seen that for the (002) oriented films of ZnO a high mobility film is achieved.

  3. Cultivating a Growth Mindset in Students at a High-Achieving High School

    ERIC Educational Resources Information Center

    Fegley, Alan D.

    2010-01-01

    The purpose of this EPP is to develop a plan for changing the mindset of a large number of Haddonfield Memorial High School (HMHS) students from a fixed mindset to a growth mindset. HMHS is by most conventional measures a high performing school. Typically 100% of the students graduate with 96% of the students attending two or four year colleges…

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

    ERIC Educational Resources Information Center

    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…

  5. Predictors of Early Growth in Academic Achievement: The Head-Toes-Knees-Shoulders Task

    ERIC Educational Resources Information Center

    McClelland, Megan M.; Cameron, Claire E.; Duncan, Robert; Bowles, Ryan P.; Acock, Alan C.; Miao, Alicia; Pratt, Megan E.

    2014-01-01

    Children's behavioral self-regulation and executive function (EF; including attentional or cognitive flexibility, working memory, and inhibitory control) are strong predictors of academic achievement. The present study examined the psychometric properties of a measure of behavioral self-regulation called the Head-Toes-Knees-Shoulders (HTKS) by…

  6. Growth in Achievement for Different Racial, Regional and Socio-Economic Groupings of Students.

    ERIC Educational Resources Information Center

    Okada, Tetsuo; And Others

    The relationship between socioeconomic status and academic achievement was studied. Cross-comparisons were made of this relationship in terms of different racial-ethnic groups, various regions of the United States, and metropolitan-nonmetropolitan locations. Subjects were sixth, ninth, and twelfth graders from the North, the South, and the West.…

  7. Achieving Finite Element Mesh Quality via Optimization of the Jacobian Matrix Norm and Associated Quantities, Part 1 - A Framework for Surface Mesh Optimization

    SciTech Connect

    Knupp, P.M.

    1999-01-18

    Structured mesh quality optimization methods are extended to optimization of unstructured triangular, quadrilateral, and mixed finite element meshes. N"ew interpretations of well-known nodally-bssed objective functions are made possible using matrices and matrix norms. The matrix perspective also suggests several new objective functions. Particularly significant is the interpretation of the Oddy metric and the Smoothness objective functions in terms of the condition number of the metric tensor and Jacobian matrix, respectively. Objective functions are grouped according to dimensionality to form weighted combinations. A simple unconstrained local optimum is computed using a modiiied N-ewton iteration. The optimization approach was implemented in the CUBIT mesh generation code and tested on several problems. Results were compared against several standard element-based quaIity measures to demonstrate that good mesh quality can be achieved with nodally-based objective functions.

  8. Does Growth Rate in Oral Reading Fluency Matter in Predicting Reading Comprehension Achievement?

    Microsoft Academic Search

    Young-Suk Kim; Yaacov Petscher; Christopher Schatschneider; Barbara Foorman

    2010-01-01

    In this study, we examined the relationship of growth trajectories of oral reading fluency, vocabulary, phonological awareness, letter-naming fluency, and nonsense word reading fluency from 1st grade to 3rd grade with reading comprehension in 1st, 2nd, and 3rd grades. Data from 12,536 children who were followed from kindergarten to 3rd grade longitudinally were used. These children were administered Dynamic Indicators

  9. Achieving growth and excellence in medicine: the case history of armed conflict and modern reconstructive surgery.

    PubMed

    Chambers, James Alan; Ray, Peter Damian

    2009-11-01

    November 11, 2009 will mark over 90 years of commemorating Armistice Day, the end of World War I. Although conflict in the Middle East reminds us that WWI failed to end all wars, it did serve as both substrate and catalyst for the development of modern plastic and reconstructive surgery. This article will outline those ingredients most directly responsible for the growth of the specialty, tracing its development in response to armed conflict, and implications for continued excellence both in reconstructive surgery and other fields in the future. PMID:20431512

  10. Optimization for LED arrays to achieve uniform near-field illumination

    Microsoft Academic Search

    Hu Zhang; Yi Li; Wei Zhang; Yize Huang; Haifang Wang; Xiaojing Yu; Huiqun Zhu; Sheng Zhou; Ruoxi Sun; Yuming Zhang

    2010-01-01

    For achieving uniform near-field illumination, this paper is based on the theory that each LED is non-perfect Lambertian emitter, whose irradiance distribution obeys the power law. Using the theory of sparrow's criterion, two methods to realizing near-field uniform irradiance of LED arrays are discussed by taking into account of the production process of LED array, a conclusion can be made

  11. High direct drive illumination uniformity achieved by multi-parameter optimization approach: a case study of Shenguang III laser facility.

    PubMed

    Tian, Chao; Chen, Jia; Zhang, Bo; Shan, Lianqiang; Zhou, Weimin; Liu, Dongxiao; Bi, Bi; Zhang, Feng; Wang, Weiwu; Zhang, Baohan; Gu, Yuqiu

    2015-05-01

    The uniformity of the compression driver is of fundamental importance for inertial confinement fusion (ICF). In this paper, the illumination uniformity on a spherical capsule during the initial imprinting phase directly driven by laser beams has been considered. We aim to explore methods to achieve high direct drive illumination uniformity on laser facilities designed for indirect drive ICF. There are many parameters that would affect the irradiation uniformity, such as Polar Direct Drive displacement quantity, capsule radius, laser spot size and intensity distribution within a laser beam. A novel approach to reduce the root mean square illumination non-uniformity based on multi-parameter optimizing approach (particle swarm optimization) is proposed, which enables us to obtain a set of optimal parameters over a large parameter space. Finally, this method is applied to improve the direct drive illumination uniformity provided by Shenguang III laser facility and the illumination non-uniformity is reduced from 5.62% to 0.23% for perfectly balanced beams. Moreover, beam errors (power imbalance and pointing error) are taken into account to provide a more practical solution and results show that this multi-parameter optimization approach is effective. PMID:25969321

  12. A conceptual framework for achieving balance between innovation and resilience in optimizing emergency department operations.

    PubMed

    Mugdh, Mrinal; Pilla, Satya

    2011-01-01

    This study presents a comprehensive review of theories and practices pertaining to emergency department operations, service innovations, and risk management, focusing on the areas of value creation and operational resilience. It includes a critical examination of how these 2 important areas both contrast with and complement each other. A dynamic systems view was applied to this effect to illuminate the interactions. On the basis of the knowledge gained from this exercise, a system-level conceptual framework was developed to suggest how to rationally optimize emergency department operations. PMID:22042143

  13. Need for optimizing catalyst loading for achieving affordable microbial fuel cells.

    PubMed

    Singh, Inderjeet; Chandra, Amreesh

    2013-08-01

    Microbial fuel cell (MFC) technology is a promising technology for electricity production together with simultaneous water treatment. Catalysts play an important role in deciding the MFC performance. In most reports, effect of catalyst - both type and quantity is not optimized. In this paper, synthesis of nanorods of MnO2-catalyst particles for application in Pt-free MFCs is reported. The effect of catalyst loading i.e., weight ratio, with respect to conducting element and binder has been optimized by employing large number of combinations. Using simple theoretical model, it is shown that too high (or low) concentration of catalysts result in loss of MFC performance. The operation of MFC has been investigated using domestic wastewater as source of bio-waste for obtaining real world situation. Maximum power density of ?61 mW/m(2) was obtained when weight ratio of catalyst and conducting species was 1:1. Suitable reasons are given to explain the outcomes. PMID:23735791

  14. Mediating Role of Coping in the Dispositional Optimism–Posttraumatic Growth Relation in Breast Cancer Patients

    Microsoft Academic Search

    Canan Büyüka?ik-Çolak; Elçin Gündo?du-Aktürk; Özlem Bozo

    2012-01-01

    The aim of the present study was to examine if coping strategies mediate dispositional optimism–posttraumatic growth relation in postoperative breast cancer patients. The data were collected from 90 patients in two hospitals. Regression analyses revealed that problem-focused coping fully mediated dispositional optimism–posttraumatic growth relation, but emotion-focused coping did not. That is, postoperative breast cancer patients who were optimistic were more

  15. A Synthesis of Optimal Controls for a Model of Tumor Growth under Angiogenic Inhibitors1

    E-print Network

    Ledzewicz, Urszula

    A Synthesis of Optimal Controls for a Model of Tumor Growth under Angiogenic Inhibitors1 Urszula for the scheduling of angio- genic inhibitors to control a vascularized tumor is considered as an optimal control for the newly forming blood vessels of the tumor. Angiogenic inhibitors like endostatin target those cells

  16. Assimilation of Field Measured LAI into Crop Growth Model based on SCE-UA Optimization Algorithm

    Microsoft Academic Search

    Jianqiang Ren; Fushui Yu; Yunyan Du; Jun Qin; Zhongxin Chen

    2009-01-01

    Assimilating external data into a crop growth model to improve accuracy of crop growth monitoring and yield estimation has been a research focus in recent years. In this paper, the shuffled complex evolution (SCE-UA) global optimization algorithm was used to assimilate field measured LAI into EPIC model to simulate yield, sowing date and nitrogen fertilizer application amount of summer maize

  17. Standardization and Optimization of Computed Tomography Protocols to Achieve Low-Dose

    PubMed Central

    Chin, Cynthia; Cody, Dianna D.; Gupta, Rajiv; Hess, Christopher P.; Kalra, Mannudeep K.; Kofler, James M.; Krishnam, Mayil S.; Einstein, Andrew J.

    2014-01-01

    The increase in radiation exposure due to CT scans has been of growing concern in recent years. CT scanners differ in their capabilities and various indications require unique protocols, but there remains room for standardization and optimization. In this paper we summarize approaches to reduce dose, as discussed in lectures comprising the first session of the 2013 UCSF Virtual Symposium on Radiation Safety in Computed Tomography. The experience of scanning at low dose in different body regions, for both diagnostic and interventional CT procedures, is addressed. An essential primary step is justifying the medical need for each scan. General guiding principles for reducing dose include tailoring a scan to a patient, minimizing scan length, use of tube current modulation and minimizing tube current, minimizing-tube potential, iterative reconstruction, and periodic review of CT studies. Organized efforts for standardization have been spearheaded by professional societies such as the American Association of Physicists in Medicine. Finally, all team members should demonstrate an awareness of the importance of minimizing dose. PMID:24589403

  18. Optimization of Bifidobacterium longum growth by use of calcium carbonate-alginate beads

    Microsoft Academic Search

    Su-Han Song; Teak-Bum Kim; Hoon-Il Oh; Deok-Kun Oh

    2003-01-01

    High concentrations of ammonium and sodium ions inhibited Bifidobacterium longum growth more than a high calcium ion concentration. The optimal pH for B. longum growth was determined to be 5.0 due to the lower accumulation of ammonium ion. To reduce the accumulation of ammonium ion and obtain an enhanced growth of B. longum, the pH of the culture containing immobilized

  19. Achieving pH control in microalgal cultures through fed-batch addition of stoichiometrically-balanced growth media

    PubMed Central

    2013-01-01

    Background Lack of accounting for proton uptake and secretion has confounded interpretation of the stoichiometry of photosynthetic growth of algae. This is also problematic for achieving growth of microalgae to high cell concentrations which is necessary to improve productivity and the economic feasibility of commercial-scale chemical production systems. Since microalgae are capable of consuming both nitrate and ammonium, this represents an opportunity to balance culture pH based on a nitrogen feeding strategy that does not utilize gas-phase CO2 buffering. Stoichiometry suggests that approximately 36 weight%N-NH4+ (balance nitrogen as NO3-) would minimize the proton imbalance and permit high-density photoautotrophic growth as it does in higher plant tissue culture. However, algal media almost exclusively utilize nitrate, and ammonium is often viewed as ‘toxic’ to algae. Results The microalgae Chlorella vulgaris and Chlamydomonas reinhardtii exclusively utilize ammonium when both ammonium and nitrate are provided during growth on excess CO2. The resulting proton imbalance from preferential ammonium utilization causes the pH to drop too low to sustain further growth when ammonium was only 9% of the total nitrogen (0.027 gN-NH4+/L). However, providing smaller amounts of ammonium sequentially in the presence of nitrate maintained the pH of a Chlorella vulgaris culture for improved growth on 0.3 gN/L to 5 gDW/L under 5% CO2 gas-phase supplementation. Bioreactor pH dynamics are shown to be predictable based on simple nitrogen assimilation as long as there is sufficient CO2 availability. Conclusions This work provides both a media formulation and a feeding strategy with a focus on nitrogen metabolism and regulation to support high-density algal culture without buffering. The instability in culture pH that is observed in microalgal cultures in the absence of buffers can be overcome through alternating utilization of ammonium and nitrate. Despite the highly regulated array of nitrogen transporters, providing a nitrogen source with a balanced degree of reduction minimizes pH fluctuations. Understanding and accommodating the behavior of nitrogen utilization in microalgae is key to avoiding ‘culture crash’ and reliance on gas phase CO2 buffering, which becomes both ineffective and cost-prohibitive for commercial-scale algal culture. PMID:23651806

  20. Optimization of culture medium for growth of Haematococcus pluvialis

    Microsoft Academic Search

    Xiandi Gong; Feng Chen

    1997-01-01

    A central composite rotatable design was used to examine the effects of five components of the medium on the growth of Haematococcus\\u000a pluvialis in batch culture. The medium components considered were: sodium acetate,potassium nitrate, major elements, trace\\u000a elements and vitamins. Within the range of the concentrations tested, a moderate concentration of the major elements significantly\\u000a enhanced algal growth, both in

  1. Optimization of growth media components for polyhydroxyalkanoate (PHA) production from organic acids by Ralstonia eutropha.

    PubMed

    Yang, Yung-Hun; Brigham, Christopher J; Budde, Charles F; Boccazzi, Paolo; Willis, Laura B; Hassan, Mohd Ali; Yusof, Zainal Abidin Mohd; Rha, ChoKyun; Sinskey, Anthony J

    2010-08-01

    We employed systematic mixture analysis to determine optimal levels of acetate, propionate, and butyrate for cell growth and polyhydroxyalkanoate (PHA) production by Ralstonia eutropha H16. Butyrate was the preferred acid for robust cell growth and high PHA production. The 3-hydroxyvalerate content in the resulting PHA depended on the proportion of propionate initially present in the growth medium. The proportion of acetate dramatically affected the final pH of the growth medium. A model was constructed using our data that predicts the effects of these acids, individually and in combination, on cell dry weight (CDW), PHA content (%CDW), PHA production, 3HV in the polymer, and final culture pH. Cell growth and PHA production improved approximately 1.5-fold over initial conditions when the proportion of butyrate was increased. Optimization of the phosphate buffer content in medium containing higher amounts of butyrate improved cell growth and PHA production more than 4-fold. The validated organic acid mixture analysis model can be used to optimize R. eutropha culture conditions, in order to meet targets for PHA production and/or polymer HV content. By modifying the growth medium made from treated industrial waste, such as palm oil mill effluent, more PHA can be produced. PMID:20535466

  2. Optimization of VGF-growth of GaAs crystals by the aid of numerical modelling

    NASA Astrophysics Data System (ADS)

    Müller, G.; Birkmann, B.

    2002-04-01

    The VGF growth of Si-doped GaAs crystals is improved considerably by optimizing the design of the crucible support and the temperature profile during the growth run. Inverse simulation with the software program CrysVUN++ was used for this procedure. The criteria for the optimized conditions are flat phase boundaries and low thermal stress during the whole growth run. The crystals which were grown according to the simulated conditions indeed showed flat phase boundaries and a very low EPD (<100 cm -2) within the whole crystal. It is shown that the growth conditions in the seed well and conical part of the crystal have a major influence on the dislocation density in the whole crystal.

  3. Growth Optimal Portfolio Selection Under Proportional Transaction Costs with Obligatory Diversification

    SciTech Connect

    Duncan, T., E-mail: duncan@math.ku.edu; Pasik Duncan, B., E-mail: bozenna@math.ku.ed [University of Kansas, Department of Mathematics (United States); Stettner, L., E-mail: stettner@impan.gov.p [Institute of Mathematics Polish Acad. Sci. (Poland)

    2011-02-15

    A continuous time long run growth optimal or optimal logarithmic utility portfolio with proportional transaction costs consisting of a fixed proportional cost and a cost proportional to the volume of transaction is considered. The asset prices are modeled as exponent of diffusion with jumps whose parameters depend on a finite state Markov process of economic factors. An obligatory portfolio diversification is introduced, accordingly to which it is required to invest at least a fixed small portion of our wealth in each asset.

  4. A Longitudinal Study on State Mathematics and Reading Assessments: Comparisons of Growth Models on Students' Achievement Scores

    ERIC Educational Resources Information Center

    Chiu, Pui Chi

    2012-01-01

    This study examines student growth on mathematics and reading assessments across academic years (Spring 2006 through Spring 2009) using three different growth models: hierarchical linear model (HLM), value-added model (VAM), and student growth percentile model (SGP). Comparisons across these three growth models were conducted to investigate the…

  5. Optimizing Bi2O3 and TiO2 to achieve the maximum non-linear electrical property of ZnO low voltage varistor

    PubMed Central

    2013-01-01

    Background In fabrication of ZnO-based low voltage varistor, Bi2O3 and TiO2 have been used as former and grain growth enhancer factors respectively. Therefore, the molar ratio of the factors is quit important in the fabrication. In this paper, modeling and optimization of Bi2O3 and TiO2 was carried out by response surface methodology to achieve maximized electrical properties. The fabrication was planned by central composite design using two variables and one response. To obtain actual responses, the design was performed in laboratory by the conventional methods of ceramics fabrication. The actual responses were fitted into a valid second order algebraic polynomial equation. Then the quadratic model was suggested by response surface methodology. The model was validated by analysis of variance which provided several evidences such as high F-value (153.6), very low P-value (<0.0001), adjusted R-squared (0.985) and predicted R-squared (0.947). Moreover, the lack of fit was not significant which means the model was significant. Results The model tracked the optimum of the additives in the design by using three dimension surface plots. In the optimum condition, the molars ratio of Bi2O3 and TiO2 were obtained in a surface area around 1.25 point that maximized the nonlinear coefficient around 20 point. Moreover, the model predicted the optimum amount of the additives in desirable condition. In this case, the condition included minimum standard error (0.35) and maximum nonlinearity (20.03), while molar ratio of Bi2O3 (1.24 mol%) and TiO2 (1.27 mol%) was in range. The condition as a solution was tested by further experiments for confirmation. As the experimental results showed, the obtained value of the non-linearity, 21.6, was quite close to the predicted model. Conclusion Response surface methodology has been successful for modeling and optimizing the additives such as Bi2O3 and TiO2 of ZnO-based low voltage varistor to achieve maximized non-linearity properties. PMID:23938168

  6. Optimization of media and fermentation conditions for the growth of Lactobacillus sakei

    Microsoft Academic Search

    T. LECHIANCOLE; A. RICCIARDI; E. PARENTE

    Factorial experiments, empirical model building and response surface analysis were used to optimize media composition and fermentation conditions for the propagation of Lactobacillus sakei, a species used as a starter in the manufacture of fermented sausages. Yeast extract, Lab-Lemco and, to a minor extent, Bacteriological peptone were found to be good sources of peptides and growth factors for L. sakei,

  7. Optimizing Growth Hormone Replacement Therapy by Dose Titration in Hypopituitary Adults

    Microsoft Academic Search

    W. M. Drake; D. COYTE; C. CAMACHO-HUBNER; N. M. JIVANJI; G. KALTSAS; D. F. WOOD; P. J. TRAINER; A. B. GROSSMAN; G. M. BESSER; J. P. MONSON

    1998-01-01

    Although growth hormone (GH) replacement therapy is increas- ingly utilized in the management of adult hypopituitary patients, optimum dosing schedules are poorly defined. The use of weight-based or surface area-based dosing may result in overtreatment, and indi- vidual variation in susceptibility on the basis of gender and other factors is now being recognized. To optimize GH replacement and to explore

  8. Optimizing and Improving the Growth Quality of ZnO Nanowire Arrays Guided

    E-print Network

    Wolfe, Patrick J.

    Optimizing and Improving the Growth Quality of ZnO Nanowire Arrays Guided by Statistical Design, optoelectronic, electrochemical, and electromechanical devices, such as ultravio- let (UV) lasers,4 light-emitting diodes,5 field emission devices,6,7 solar cells,8 as well as piezo-nanogenerators.9,10 In general, Zn

  9. Optimal taxation in a growth model with public consumption and home production

    Microsoft Academic Search

    Jie Zhang; James Davies; Jinli Zeng; Stuart McDonald

    2008-01-01

    In a neoclassical growth model with public consumption, we show the following Pareto optimal tax rules. The government should tax leisure and private consumption at the same rate, and subsidize net investment at the same rate it taxes net capital income. Also, it should tax capital income more heavily than labor income. In an extension for home production, the additional

  10. J. AMER. SOC. HORT. SCI. 126(5):638643. 2001. Optimization of Transpiration and Potential Growth

    E-print Network

    Lieth, J. Heinrich

    to various containerized substrates, which have superior physical characteristics as com- pared to soilJ. AMER. SOC. HORT. SCI. 126(5):638­643. 2001. Optimization of Transpiration and Potential Growth for Soil and Water Sciences, Faculty of Agriculture, The Hebrew University of Jerusalem, P.O. Box 12

  11. Spot-shadowing optimization to mitigate damage growth in a high-energy-laser amplifier chain

    E-print Network

    Fienup, James R.

    a programmable mask or a static apodizer mounted on a translation stage at an image-relay plane earlierSpot-shadowing optimization to mitigate damage growth in a high-energy-laser amplifier chain Seung for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA 2

  12. Parameter continuity of the ergodic cost for a growth optimal portfolio with proportional transaction costs

    Microsoft Academic Search

    Tyrone E. Duncan; Bozenna Pasik-duncan; Lukasz Stettner

    2008-01-01

    Some results are given for a continuous time long run growth optimal portfolio that has proportional costs consisting of the sum of a fixed proportional cost and a cost that is proportional to the volume of each transaction. An obligatory portfolio diversification is given that requires at least a small portion of the wealth be invested in each asset. It

  13. The Effects of a Growth Mindset Intervention on the Beliefs about Intelligence, Effort Beliefs, Achievement Goal Orientations, and Academic Self-Efficacy of LD Students with Reading Difficulties

    ERIC Educational Resources Information Center

    Baldridge, Mary Caufield

    2010-01-01

    The overall purpose of this study was to examine the effects of a "growth mindset" intervention on the beliefs about intelligence, effort beliefs, achievement goals, and academic self-efficacy of learning disabled (LD) students with reading difficulties. The treatment group consisted of 12 high school LD students with reading difficulties. This…

  14. Improved film growth and flatband voltage control of ALD HfO2 and Hf-Al-O with n+ poly-Si gates using chemical oxides and optimized post-annealing

    Microsoft Academic Search

    G. D. Wilk; M. L. Green; M.-Y. Ho; B. W. Busch; T. W. Sorsch; F. P. Klemens; B. Brijs; R. B. van Dover; A. Kornblit; T. Gustafsson; E. Garfunkel; S. Hillenius; D. Monroe; P. Kalavade; J. M. Hergenrother

    2002-01-01

    We demonstrate for the first time that chemical oxide underlayers ?5 Å thick provide improved growth and flatband voltage control of ALD HfO2 films compared to thermal oxides. Optimized annealing conditions are shown to greatly reduce both fixed charge and interfacial oxide growth in the high-? stacks. Extremely small flatband voltage shifts of <30 mV are achieved, corresponding to a

  15. Optimization of photobioreactor growth conditions for a cyanobacterium expressing mosquitocidal Bacillus thuringiensis Cry proteins.

    PubMed

    Ketseoglou, Irene; Bouwer, Gustav

    2013-08-10

    An Anabaena strain (PCC 7120#11) that was genetically engineered to express Bacillus thuringiensis subsp. israelensis cry genes has shown good larvicidal activity against Anopheles arabiensis, a major vector of malaria in Africa. Response surface methodology was used to evaluate the relationship between key growth factors and the volumetric productivity of PCC 7120#11 in an indoor, flat-plate photobioreactor. The interaction of input CO? concentration and airflow rate had a statistically significant effect on the volumetric productivity of PCC 7120#11, as did the interaction of airflow rate and photosynthetic photon flux density. Model-based numerical optimization indicated that the optimal factor level combination for maximizing PCC 7120#11 volumetric productivity was a photosynthetic photon flux density of 154 ?mol m?² s?¹ and air enriched with 3.18% (v/v) CO? supplied at a flow rate of 1.02 vessel volumes per minute. At the levels evaluated in the study, none of the growth factors had a significant effect on the median lethal concentration of PCC 7120#11 against An. arabiensis larvae. This finding is important because loss of mosquitocidal activity under growth conditions that maximize volumetric productivity would impact on the feasibility of using PCC 7120#11 in malaria vector control programs. The study showed the usefulness of response surface methodology for determination of the optimal growth conditions for a cyanobacterium that is genetically engineered to have larvicidal activity against malaria vectors. PMID:23732832

  16. Comparison of Three Growth Modeling Techniques in the Multilevel Analysis of Longitudinal Academic Achievement Scores: Latent Growth Modeling, Hierarchical Linear Modeling, and Longitudinal Profile Analysis via Multidimensional Scaling

    ERIC Educational Resources Information Center

    Shin, Tacksoo

    2007-01-01

    This study introduces three growth modeling techniques: latent growth modeling (LGM), hierarchical linear modeling (HLM), and longitudinal profile analysis via multidimensional scaling (LPAMS). It compares the multilevel growth parameter estimates and potential predictor effects obtained using LGM, HLM, and LPAMS. The purpose of this multilevel…

  17. Super-optimal CO2 reduces seed yield but not vegetative growth in wheat

    NASA Technical Reports Server (NTRS)

    Grotenhuis, T. P.; Bugbee, B.

    1997-01-01

    Although terrestrial atmospheric CO2 levels will not reach 1000 micromoles mol-1 (0.1%) for decades, CO2 levels in growth chambers and greenhouses routinely exceed that concentration. CO2 levels in life support systems in space can exceed 10000 micromoles mol-1(1%). Numerous studies have examined CO2 effects up to 1000 micromoles mol-1, but biochemical measurements indicate that the beneficial effects of CO2 can continue beyond this concentration. We studied the effects of near-optimal (approximately 1200 micromoles mol-1) and super-optimal CO2 levels (2400 micromoles mol-1) on yield of two cultivars of hydroponically grown wheat (Triticum aestivum L.) in 12 trials in growth chambers. Increasing CO2 from sub-optimal to near-optimal (350-1200 micromoles mol-1) increased vegetative growth by 25% and seed yield by 15% in both cultivars. Yield increases were primarily the result of an increased number of heads per square meter. Further elevation of CO2 to 2500 micromoles mol-1 reduced seed yield by 22% (P < 0.001) in cv. Veery-10 and by 15% (P < 0.001) in cv. USU-Apogee. Super-optimal CO2 did not decrease the number of heads per square meter, but reduced seeds per head by 10% and mass per seed by 11%. The toxic effect of CO2 was similar over a range of light levels from half to full sunlight. Subsequent trials revealed that super-optimal CO2 during the interval between 2 wk before and after anthesis mimicked the effect of constant super-optimal CO2. Furthermore, near-optimal CO2 during the same interval mimicked the effect of constant near-optimal CO2. Nutrient concentration of leaves and heads was not affected by CO2. These results suggest that super-optimal CO2 inhibits some process that occurs near the time of seed set resulting in decreased seed set, seed mass, and yield.

  18. Effects of optimal and supra-optimal salinity stress on antioxidative defence, osmolytes and in vitro growth responses in Sesuvium portulacastrum L

    Microsoft Academic Search

    Vinayak H. Lokhande; Tukaram D. Nikam; Vikas Y. Patade; Mahendra L. Ahire; P. Suprasanna

    2011-01-01

    The effect of optimal and supra-optimal concentrations (0, 200, 400 or 600 mM) of NaCl on the growth, osmotic adjustment and\\u000a antioxidant enzyme defence was studied in the in vitro cultures of Sesuvium portulacastrum. A significant increase in growth, tissue water content (TWC) and fresh to dry weight ratio (FW\\/DW) was observed in the shoots\\u000a exposed to 200 mM salt. Minimum damage

  19. Optimized clinical performance of growth hormone with an expanded genetic code

    PubMed Central

    Cho, Ho; Daniel, Tom; Buechler, Ying Ji; Litzinger, David C.; Maio, Zhenwei; Putnam, Anna-Maria Hays; Kraynov, Vadim S.; Sim, Bee-Cheng; Bussell, Stuart; Javahishvili, Tsotne; Kaphle, Sami; Viramontes, Guillermo; Ong, Mike; Chu, Stephanie; GC, Becky; Lieu, Ricky; Knudsen, Nick; Castiglioni, Paola; Norman, Thea C.; Axelrod, Douglas W.; Hoffman, Andrew R.; Schultz, Peter G.; DiMarchi, Richard D.; Kimmel, Bruce E.

    2011-01-01

    The ribosomal incorporation of nonnative amino acids into polypeptides in living cells provides the opportunity to endow therapeutic proteins with unique pharmacological properties. We report here the first clinical study of a biosynthetic protein produced using an expanded genetic code. Incorporation of p-acetylphenylalanine (pAcF) at distinct locations in human growth hormone (hGH) allowed site-specific conjugation with polyethylene glycol (PEG) to produce homogeneous hGH variants. A mono-PEGylated mutant hGH modified at residue 35 demonstrated favorable pharmacodynamic properties in GH-deficient rats. Clinical studies in GH-deficient adults demonstrated efficacy and safety comparable to native human growth hormone therapy but with increased potency and reduced injection frequency. This example illustrates the utility of nonnative amino acids to optimize protein therapeutics in an analogous fashion to the use of medicinal chemistry to optimize conventional natural products, low molecular weight drugs, and peptides. PMID:21576502

  20. Optimal management strategies to control local population growth or population spread may not be the same.

    PubMed

    Shea, Katriona; Jongejans, Eelke; Skarpaas, Olav; Kelly, Dave; Sheppard, Andy W

    2010-06-01

    The objective of most pest management programs is to "control" the pest species. However, optimal control of local abundance and population growth may require different management strategies than optimal control of spatial spread. We use coupled demographic-dispersal models to address the relative importance of different management approaches to these two main control objectives for the invasive thistle Carduus nutans. The models are parameterized with data from thistle populations in the native (France) and invaded ranges (Australia and New Zealand). We assess a wide range of commonly used management strategies for their absolute and relative impacts on population growth and spread in both invaded-range scenarios. The projected population growth rate in New Zealand is more than twice that in Australia, while the spread rate is more than four times the Australian value. In general, spread and growth are both most strongly affected by the same life cycle transitions; however, in a few cases certain vital rates disproportionately affect either spread or growth. The transition that represents the contribution of large rosettes in one year to the number of large rosettes in the following year (the large rosette-large rosette transition) in Australia is dominated by reproduction (rather than survival) and hence is relatively more important to spread than to population growth. In New Zealand, the small rosette-small rosette transition is also predominantly dispersal-related. However, establishment of small plants from the seed bank contributes more to population growth than spread, as no dispersal is involved. The fine-resolution vital-rate-based modeling approach allows us to identify potentially novel optimal management strategies: approaches that reduce microsite availability show promise for reducing both population growth and spread, while strategies that affect dispersal parameters will affect spread. Additionally, the relative ranking of some biocontrol agents shifts depending on whether control of population growth or population spread is the desired outcome and therefore could alter which of the agents are preferred for release in a new area. The possibility of differences in ranked agent effectiveness has been predicted theoretically, but never before demonstrated using field data. PMID:20597297

  1. Relationships Between Genomic G+C Content, RNA Secondary Structures, and Optimal Growth Temperature in Prokaryotes

    Microsoft Academic Search

    Nicolas Galtier; J. R. Lobry

    1997-01-01

    .   G:C pairs are more stable than A:T pairs because they have an additional hydrogen bond. This has led to many studies on the\\u000a correlation between the guanine+cytosine (G+C) content of nucleic acids and temperature over the last 20 years. We collected\\u000a the optimal growth temperatures (Topt) and the G+C contents of genomic DNA; 23S, 16S, and 5S ribosomal RNAs;

  2. An Axenic Plant Culture System for Optimal Growth in Long-Term Studies

    Microsoft Academic Search

    Amelia Henry; William Doucette; Jeanette Norton; Scott Jones; Julie Chard; Bruce Bugbee

    2006-01-01

    Thesymbioticco-evolutionofplantsandmicrobesleadstodifficulties in understanding which of the two components is responsible for a given environmental response. Plant-microbe studies greatly benefit from the abilitytogrowplantsinaxenic(sterile)culture.Severalstudieshaveused axenic plant culture systems, but experimental procedures are often poorly documented, the plant growth environment is not optimal, and axenic conditions are not rigorously verified. We developed a unique axenic system using inert components that promotes plant health

  3. Project Luna Succendo: The Lunar Evolutionary Growth-Optimized (LEGO) Reactor

    Microsoft Academic Search

    John Darrell Bess

    2008-01-01

    A final design has been established for a basic Lunar Evolutionary Growth-Optimized (LEGO) Reactor using current and near-term technologies. The LEGO Reactor is a modular, fast-fission, heatpipe-cooled, clustered-reactor system for lunar-surface power generation. The reactor is divided into subcritical units that can be safely launched within lunar shipments from the Earth, and then emplaced directly into holes drilled into the

  4. Optimization of medium composition for enhancing growth of Lactobacillus rhamnosus PEN using response surface methodology.

    PubMed

    Polak-Berecka, Magdalena; Wa?ko, Adam; Kordowska-Wiater, Monika; Podle?ny, Marcin; Targo?ski, Zdzis?aw; Kubik-Komar, Agnieszka

    2010-01-01

    Response surface methodology was used to optimize media components such as carbon and nitrogen (simple and complex) sources, mineral agents and growth factors (B vitamins, amino acids) for enhancing the biomass production of Lactobacillus rhamnosus PEN. For screening experiment the following carbon sources were selected: glucose, glucose+pyruvate, glucose+citrate, glucose+lactate, galactose, fructose, lactose, sucrose, maltose, lactulose, fructooligosaccharides, maltodextrins DP 4-7 and DP 13-17. Nitrogen sources such as yeast extract, meat extract and peptone K were used in lower concentrations than in MRS medium which served as a control. All experiments were run at 37 degrees C for 24-48 h under stationary conditions. Constituents chosen after the first screening experiments were further screened by the Plackett-Burman design. Glucose and sodium pyruvate, meat extract, potassium phosphate, sodium acetate, and ammonium citrate were chosen as promising medium components for further optimization studies. By solving the regression equation and analyzing the response surface carton, optimal concentrations of the components were determined as: glucose (13.4 g/l), sodium pyruvate (3.4 g/l), meat extract (7.2 g/l), potassium phosphate (2.0 g/I), sodium acetate (5.0 g/1) and ammonium citrate (2.0 g/l). In comparison to MRS broth the optimal medium contained fewer ingredients and in modified amounts but Lb. ihamnosus PEN showed better growth activity. Biomass concentration (as dry cell weight) of bacteria cultivated in optimal medium at bioreactor conditions was 5.5 g/l after 16 h of incubation, being higher in comparison with bacterial growth in MRS medium (1.9 g/l) under the same conditions. Moreover, the new medium was less expensive. PMID:20734756

  5. Direct and Indirect Longitudinal Effects of Parental Involvement on Student Achievement: Second-Order Latent Growth Modeling Across Ethnic Groups

    Microsoft Academic Search

    Sehee Hong; Hsiu-Zu Ho

    2005-01-01

    The present study on the influence of parental involvement on students' academic achievement overcame limitations in current research by including simultaneous considerations of multidimensional, longitudinal, mediational, and ethnic factors. Results indicated (a) significant ethnic differences in the direct effects of parental involvement on academic achievement; (b) consistent indirect effects, mediated by student educational aspiration, across all 4 ethnic groups for

  6. A Comparison of the Effect of Instructional Time and Instructional Program on Reading Achievement Growth of Kindergarten Students

    ERIC Educational Resources Information Center

    Warner, Darlene Ovyn

    2012-01-01

    This dissertation study examined reading achievement among students enrolled in half-day kindergarten (HDK) and full-day kindergarten (FDK) programs. First, a review of the research on reading achievement in students in both HDK and FDK programs was presented. Next, the study, including the research questions, study design, and analysis plan, were…

  7. Scaling and optimal synergy: Two principles determining microbial growth in complex media

    NASA Astrophysics Data System (ADS)

    Massucci, Francesco Alessandro; Guimerà, Roger; Nunes Amaral, Luís A.; Sales-Pardo, Marta

    2015-06-01

    High-throughput experimental techniques and bioinformatics tools make it possible to obtain reconstructions of the metabolism of microbial species. Combined with mathematical frameworks such as flux balance analysis, which assumes that nutrients are used so as to maximize growth, these reconstructions enable us to predict microbial growth. Although such predictions are generally accurate, these approaches do not give insights on how different nutrients are used to produce growth, and thus are difficult to generalize to new media or to different organisms. Here, we propose a systems-level phenomenological model of metabolism inspired by the virial expansion. Our model predicts biomass production given the nutrient uptakes and a reduced set of parameters, which can be easily determined experimentally. To validate our model, we test it against in silico simulations and experimental measurements of growth, and find good agreement. From a biological point of view, our model uncovers the impact that individual nutrients and the synergistic interaction between nutrient pairs have on growth, and suggests that we can understand the growth maximization principle as the optimization of nutrient synergies.

  8. Simple processes for optimized growth and harvest of Ettlia sp. by pH control using CO2 and light irradiation.

    PubMed

    Yoo, Chan; La, Hyun-Joon; Kim, Sun-Chang; Oh, Hee-Mock

    2015-02-01

    Microalgae cultures show wide range of pH depending on the availability of light and CO2 for their strain specific photosynthesis. Thus, the modulation of light irradiation and CO2 supply can be applied for the pH control of microalgae cultures. The optimal pH of Ettlia sp. YC001, for phototrophic growth and auto-flocculation was investigated by controlling light irradiation and 10% CO2 supply. Ettlia sp. YC001 showed the highest biomass productivity, 96.7?mg?L(-1) ?d(-1) , at pH 8.5. The flocculating activity of Ettlia sp. YC001 showed a sigmoid pattern with pH increase and was above 70% at pH 10.5. Based on these differentiated optimal pH regimes for the growth and flocculation, an integrated process consisting of cultivation and settling vessels was proposed. The integrated process demonstrated that high flocculation activity of Ettlia sp. YC001 could be achieved in the settling vessel with various hydraulic retention times by only irradiation of light to maintain high pH while maintaining the optimal growth in cultivation vessel with the light irradiation and CO2 supply at pH 8.5. Thus, the proposed strategy for pH control would provide a simple, cost-effective, and flexible design and operation for microalgae cultivation-harvest systems. PMID:25182602

  9. The role of maternal smoking in effect of fetal growth restriction on poor scholastic achievement in elementary school.

    PubMed

    Burstyn, Igor; Kuhle, Stefan; Allen, Alexander C; Veugelers, Paul

    2012-02-01

    Fetal growth restriction and maternal smoking during pregnancy are independently implicated in lowering intellectual attainment in children. We hypothesized that only reduction of fetal growth that is attributable to extrinsic causes (e.g., maternal smoking) affects intellectual development of a child. Cross-sectional survey of 3,739 students in Nova Scotia (Canada) in 2003 was linked with the perinatal database, parental interviews on socio-demographic factors and the performance on standardized tests when primarily 11-12 years of age, thereby forming a retrospective cohort. Data was analyzed using hierarchical logistic regression with correction for clustering of children within schools. The risk of poor test result among children born small-for-gestational-age (SGA) to mothers who smoked was 29.4%, higher than in any other strata of maternal smoking and fetal growth. The adjusted odds ratio among SGA children born to mothers who smoked was the only one elevated compared to children who were not growth restricted and born to mothers who did not smoke (17.0%, OR = 1.46, 95% CI 1.02, 2.09). Other perinatal, maternal and socio-demographic factors did not alter this pattern of effect modification. Heterogeneity of etiology of fetal growth restriction should be consider in studies that address examine its impact on health over life course. PMID:22470300

  10. Characterization of local quadratic growth for strong minima in the optimal control of semi-linear elliptic equations

    E-print Network

    Paris-Sud XI, Université de

    Characterization of local quadratic growth for strong minima in the optimal control of semi-linear elliptic equations T´erence Bayen J. Fr´ed´eric Bonnans Francisco J. Silva§ September 11, 2013 Abstract In this article we consider an optimal control problem of a semi-linear elliptic equation, with bound constraints

  11. Nuclear Symbiosis - A Means to Achieve Sustainable Nuclear Growth while Limiting the Spread of Sensititive Nuclear Technology

    Microsoft Academic Search

    David Shropshire

    2009-01-01

    Global growth of nuclear energy in the 21st century is creating new challenges to limit the spread of nuclear technology without hindering adoption in countries now considering nuclear power. Independent nuclear states desire autonomy over energy choices and seek energy independence. However, this independence comes with high costs for development of new indigenous fuel cycle capabilities. Nuclear supplier states and

  12. Fat-soluble vitamin and micromineral concentrations in preruminant dairy calves fed to achieve different growth rates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Calf nutrition programs often limit nutrient intake from milk replacer during the first few weeks of life to promote dry-feed intake and early weaning. Recent studies indicate that feeding increased amounts of milk replacer with higher protein concentration improves growth performance and feed effi...

  13. An Investigation of Language-Minority Children: Demographic Characteristics, Initial Performance, and Growth in Achievement. CSE Technical Report 686

    ERIC Educational Resources Information Center

    Ready, Douglas; Tindal, Gerald

    2006-01-01

    Research on language-minority (LM) children has generally focused on language as the primary mediator of student achievement without considering other student demographic characteristics. This is unfortunate, as studies that approach language-minority children as a homogeneous group will misestimate relationships between language status and…

  14. Growth in Literacy and Numeracy Achievement: Evidence and Explanations of a Summer Slowdown in Low Socio-Economic Schools

    ERIC Educational Resources Information Center

    Vale, Colleen; Weaven, Mary; Davies, Anne; Hooley, Neil; Davidson, Kristy; Loton, Daniel

    2013-01-01

    The phenomenon of summer slide or setback has gained a great deal of attention in the USA. It is understood to account for as much as 80% of the difference in achievement for students between low and high socio-economic families over their elementary schooling. In a mixed method longitudinal study of reforms in low socio-economic school…

  15. Evidence of a Differential Effect of Ability Grouping on the Reading Achievement Growth of Language-Minority Hispanics

    ERIC Educational Resources Information Center

    Robinson, Joseph P.

    2008-01-01

    Ability grouping is sometimes thought to exacerbate inequality by increasing achievement gaps; however, ability grouping may in fact benefit a fast growing and often marginalized student population: children from non-English-speaking home environments. The level-appropriate, small-group instruction received in reading ability groups may be…

  16. Determining the optimal stacking fault energy for achieving high ductility in ultrafine-grained Cu–Zn alloys

    Microsoft Academic Search

    Y. H. Zhao; X. Z. Liao; Z. Horita; T. G. Langdon; Y. T. Zhu

    2008-01-01

    Bulk ultrafine-grained (UFG) materials produced by severe plastic deformation (SPD) often have low ductility. A previous study demonstrated the possibility of lowering the stacking fault energy to simultaneously increase the strength and ductility. This paper demonstrates, there exists an optimal stacking fault energy for the best ductility in UFG Cu–Zn alloys processed by the same SPD processing. When the stacking

  17. Language and Verbal Memory in Individuals with a History of Autism Spectrum Disorders Who Have Achieved Optimal Outcomes

    ERIC Educational Resources Information Center

    Tyson, Katherine; Kelley, Elizabeth; Fein, Deborah; Orinstein, Alyssa; Troyb, Eva; Barton, Marianne; Eigsti, Inge-Marie; Naigles, Letitia; Schultz, Robert T.; Stevens, Michael; Helt, Molly; Rosenthal, Michael

    2014-01-01

    Some individuals who lose their autism spectrum disorder diagnosis may continue to display subtle weaknesses in language. We examined language and verbal memory in 44 individuals with high-functioning autism (HFA), 34 individuals with "optimal outcomes" (OO) and 34 individuals with typical development (TD). The OO group scored in the…

  18. Further developments in the controlled growth approach for optimal structural synthesis

    NASA Technical Reports Server (NTRS)

    Hajela, P.

    1982-01-01

    It is pointed out that the use of nonlinear programming methods in conjunction with finite element and other discrete analysis techniques have provided a powerful tool in the domain of optimal structural synthesis. The present investigation is concerned with new strategies which comprise an extension to the controlled growth method considered by Hajela and Sobieski-Sobieszczanski (1981). This method proposed an approach wherein the standard nonlinear programming (NLP) methodology of working with a very large number of design variables was replaced by a sequence of smaller optimization cycles, each involving a single 'dominant' variable. The current investigation outlines some new features. Attention is given to a modified cumulative constraint representation which is defined in both the feasible and infeasible domain of the design space. Other new features are related to the evaluation of the 'effectiveness measure' on which the choice of the dominant variable and the linking strategy is based.

  19. Production of cloned human leukocyte interferon by Bacillus subtilis: optimal production is connected with restrained growth.

    PubMed Central

    Meyer, H P; Fiechter, A

    1985-01-01

    Bacillus subtilis, transformed with a plasmid containing the human alpha-2 (leukocyte) interferon gene, was cultivated in batch and continuous culture in a complex medium. In continuous culture with dissolved oxygen of less than 10% of air saturation, the extracellular interferon titer decreased sharply when the growth rate was lower or higher than the optimal one (mu = 0.14 h-1). Thus, a relatively low growth rate was best for extracellular interferon production, and oxygen limitation enhanced interferon production. The mean output rate in batch culture after successful harvest was 20 X 10(6) IU/liter per h and the maximal output rate in continuous culture was 14 X 10(6) IU/liter per h. PMID:3931551

  20. Monoraphidium sp. as an algal feedstock for biodiesel: Determining optimal growth conditions in wastewater

    NASA Astrophysics Data System (ADS)

    Davidson, Zachary William

    This thesis set out to investigate different conditions for growth of the freshwater algal species Monoraphidium sp. for use as a feedstock for biodiesel. The algae was inoculated into effluent gathered from a local water treatment plant and placed into 50gal mesocosms. Cells were grown at large scale in wastewater, harvested, and run through extractions to collect lipids (26%DW). The lipids were then turned into biodiesel. The algae also removed most of the pollutants in the wastewater, lowering nitrate and phosphate levels usually to less than 1mg/L. Erlenmeyer flask cultures (1L) were used to determine optimal growth conditions for temperature (10°C), light intensity (30microE/m2/sec with a 10 hour photoperiod), and initial inoculation density (1x104cells/mL). The addition of bicarbonate during the initial or exponential growth phase had no effect on growth. It was concluded that Monoraphidium sp. grown in USDA Hardiness Zone 5 is capable of producing biodiesel.

  1. Codon optimization, promoter and expression system selection that achieved high-level production of Yarrowia lipolytica lipase in Pichia pastoris.

    PubMed

    Zhou, Wen-Jing; Yang, Jiang-Ke; Mao, Lin; Miao, Li-Hong

    2015-04-01

    Lipase (EC 3.1.1.3) stands amongst the most important and promising biocatalysts for industrial applications. In this study, in order to realize a high-level expression of the Yarrowia lipolytica lipase gene in Pichia pastoris, we optimized the codon of LIP2 by de novo gene design and synthesis, which significantly improved the lipase expression when compared to the native lip2 gene. We also comparatively analyzed the effects of the promoter types (PAOX1 and PFLD1) and the Pichia expression systems, including the newly developed PichiaPink system, on lipase production and obtained the optimal recombinants. Bench-top scale fermentation studies indicated that the recombinant carrying the codon-optimized lipase gene syn-lip under the control of promoter PAOX1 has a significantly higher lipase production capacity in the fermenter than other types of recombinants. After undergoing methanol inducible expression for 96h, the wet cell weight of Pichia, the lipase activity and the protein content in the fermentation broth reached their highest values of 262g/L, 38,500U/mL and 2.82g/L, respectively. This study has not only greatly facilitated the bioapplication of lipase in industrial fields but the strategies utilized, such as de novo gene design and synthesis, the comparative analysis among promoters and different generations of Pichia expression systems will also be useful as references for future work in this field. PMID:25765312

  2. Achievements and limitations in optimized GaAs films grown on Si by molecular-beam epitaxy

    NASA Astrophysics Data System (ADS)

    Georgakilas, A.; Panayotatos, P.; Stoemenos, J.; Mourrain, J.-L.; Christou, A.

    1992-03-01

    The growth of high-quality films of GaAs on Si substrates, applicable in particular to optoelectronic devices for cointegration in optical interconnects, has been systematically studied. The effects of silicon substrate orientation, postgrowth treatment, as well as multilayer and especially, silicon buffer layers are addressed. The most crucial parameter for device orientation and film uniformity is the complete absence of antiphase boundaries which increase leakage, degrade mobilities, and seem to result in interface 2D electron gas in substrates misoriented toward 110-line. Absolute smooth GaAs morphology is obtained using a MBE grown Si buffer layer and controlling the orientation of the GaAs films so that the 110-line direction is parallel to the 110-line misorientation direction of the vicinal (001) substrates. This can be ensured by an As4 prelayer grown at 350 C. A double 2 x 1 domain Si surface seems to be preferable as it allows the choice of such a GaAs orientation. GaAs growth is then D from the very early stage of growth, following the homogeneous nucleation of 2D GaAs islands, resulting in the complete elimination of planar faults. A perfectly regular displacement-type moire pattern in the GaAs/Si interface is then observed.

  3. SU-E-T-387: Achieving Optimal Patient Setup Imaging and Treatment Workflow Configurations in Multi-Room Proton Centers

    SciTech Connect

    Zhang, H; Prado, K; Langen, K; Yi, B; Mehta, M; Regine, W; D'Souza, W [University of Maryland School of Medicine, Baltimore, MD (United States)

    2014-06-01

    Purpose: To simulate patient flow in proton treatment center under uncertainty and to explore the feasibility of treatment preparation rooms to improve patient throughput and cyclotron utilization. Methods: Three center layout scenarios were modeled: (S1: In-Tx room imaging) patient setup and imaging (planar/volumetric) performed in treatment room, (S2: Patient setup in preparation room) each treatment room was assigned with preparation room(s) that was equipped with lasers only for patient setup and gross patient alignment, and (S3: Patient setup and imaging in preparation room) preparation room(s) was equipped with laser and volumetric imaging for patient setup, gross and fine patient alignment. A 'snap' imaging was performed in treatment room. For each scenario, the number of treatment rooms and the number of preparation rooms serving each treatment room were varied. We examined our results (average of 100 16-hour (two shifts) working days) by evaluating patient throughput and cyclotron utilization. Results: When the number of treatment rooms increased ([from, to]) [1, 5], daily patient throughput increased [32, 161], [29, 184] and [27, 184] and cyclotron utilization increased [13%, 85%], [12%, 98%], and [11%, 98%] for scenarios S1, S2 and S3 respectively. However, both measures plateaued after 4 rooms. With the preparation rooms, the throughput and the cyclotron utilization increased by 14% and 15%, respectively. Three preparation rooms were optimal to serve 1-3 treatment rooms and two preparation rooms were optimal to serve 4 or 5 treatment rooms. Conclusion: Patient preparation rooms for patient setup may increase throughput and decrease the need for additional treatment rooms (cost effective). Optimal number of preparation rooms serving each gantry room varies as a function of treatment rooms and patient setup scenarios. A 5th treatment room may not be justified by throughput or utilization.

  4. Imaging Live Cells at the Nanometer-Scale with Single-Molecule Microscopy: Obstacles and Achievements in Experiment Optimization for Microbiology

    PubMed Central

    Haas, Beth L.; Matson, Jyl S.; DiRita, Victor J.; Biteen, Julie S.

    2015-01-01

    Single-molecule fluorescence microscopy enables biological investigations inside living cells to achieve millisecond- and nanometer-scale resolution. Although single-molecule-based methods are becoming increasingly accessible to non-experts, optimizing new single-molecule experiments can be challenging, in particular when super-resolution imaging and tracking are applied to live cells. In this review, we summarize common obstacles to live-cell single-molecule microscopy and describe the methods we have developed and applied to overcome these challenges in live bacteria. We examine the choice of fluorophore and labeling scheme, approaches to achieving single-molecule levels of fluorescence, considerations for maintaining cell viability, and strategies for detecting single-molecule signals in the presence of noise and sample drift. We also discuss methods for analyzing single-molecule trajectories and the challenges presented by the finite size of a bacterial cell and the curvature of the bacterial membrane. PMID:25123183

  5. An axenic plant culture system for optimal growth in long-term studies.

    PubMed

    Henry, Amelia; Doucette, William; Norton, Jeanette; Jones, Scott; Chard, Julie; Bugbee, Bruce

    2006-01-01

    The symbiotic co-evolution of plants and microbes leads to difficulties in understanding which of the two components is responsible for a given environmental response. Plant-microbe studies greatly benefit from the ability to grow plants in axenic (sterile) culture. Several studies have used axenic plant culture systems, but experimental procedures are often poorly documented, the plant growth environment is not optimal, and axenic conditions are not rigorously verified. We developed a unique axenic system using inert components that promotes plant health and can be kept sterile for at least 70 d. Crested wheatgrass (Agropyron cristatum cv. CDII) plants were grown in sand within flow-through glass columns that were positively pressured with filtered air. Plant health was optimized by regulating temperature, light level, CO2 concentration, humidity, and nutrients. The design incorporates several novel aspects, such as pretreatment of the sand with Fe, graduated sand layers to optimize the air-water balance of the root zone, and modification of a laminar flow hood to serve as a plant growth chamber. Adaptations of several sterile techniques were necessary for maintenance of axenic conditions. Axenic conditions were verified by plating and staining leachates as well as a rhizoplane stain. This system was designed to study nutrient and water stress effects on root exudates, but is useful for assessing a broad range of plant-microbe-environment interactions. Based on total organic C analysis, 74% of exudates was recovered in the leachate, 6% was recovered in the bulk sand, and 17% was recovered in the rhizosphere sand. Carbon in the leachate after 70 d reached 255 microg d(-1). Fumaric, malic, malonic, oxalic, and succinic acids were measured as components of the root exudates. PMID:16510704

  6. Hype, harmony and human factors: applying user-centered design to achieve sustainable telehealth program adoption and growth.

    PubMed

    Rossos, P G; St-Cyr, O; Purdy, B; Toenjes, C; Masino, C; Chmelnitsky, D

    2015-01-01

    Despite decades of international experience with the use of information and communication technologies in healthcare delivery, widespread telehealth adoption remains limited and progress slow. Escalating health system challenges related to access, cost and quality currently coincide with rapid advancement of affordable and reliable internet based communication technologies creating unprecedented opportunities and incentives for telehealth. In this paper, we will describe how Human Factors Engineering (HFE) and user-centric elements have been incorporated into the establishment of telehealth within a large academic medical center to increase acceptance and sustainability. Through examples and lessons learned we wish to increase awareness of HFE and its importance in the successful implementation, innovation and growth of telehealth programs. PMID:25980714

  7. Modelling and Optimization of Nannochloropsis and Chlorella Growth for Various Locations and Seasons

    NASA Astrophysics Data System (ADS)

    Gharagozloo, P. E.

    2014-12-01

    Efficient production of algal biofuels could reduce dependence on foreign oil providing domestic renewable energy. Algae-based biofuels are attractive for their large oil yield potential despite decreased land use and natural-resource requirements compared to terrestrial energy crops. Important factors controlling algal-lipid productivity include temperature, nutrient availability, salinity, pH, and the light-to-biomass conversion rate. Computational approaches allow for inexpensive predictions of algae-growth kinetics for various bioreactor sizes and geometries without multiple, expensive measurement systems. In this work, we parameterize our physics-based computational algae growth model for the marine Nannochloropsis oceanica and freshwater Chlorella species. We then compare modelling results with experiments conducted in identical raceway ponds at six geographical locations in the United States (Hawaii, California, Arizona, Ohio, Georgia, and Florida) and three seasons through the Algae Testbed Public Private Partnership - Unified Field Studies. Results show that the computational model effectively predicts algae growth in systems across varying environments and identifies the causes for reductions in algal productivities. The model is then used to identify improvements to the cultivation system to produce higher biomass yields. This model could be used to study the effects of scale-up including the effects of predation, depth-decay of light (light extinction), and optimized nutrient and CO2 delivery. As more multifactorial data are accumulated for a variety of algal strains, the model could be used to select appropriate algal species for various geographic and climatic locations and seasons. Applying the model facilitates optimization of pond designs based on location and season.

  8. Optimized polymeric film-based nitric oxide delivery inhibits bacterial growth in a mouse burn wound model.

    PubMed

    Brisbois, Elizabeth J; Bayliss, Jill; Wu, Jianfeng; Major, Terry C; Xi, Chuanwu; Wang, Stewart C; Bartlett, Robert H; Handa, Hitesh; Meyerhoff, Mark E

    2014-10-01

    Nitric oxide (NO) has many biological roles (e.g. antimicrobial agent, promoter of angiogenesis, prevention of platelet activation) that make NO releasing materials desirable for a variety of biomedical applications. Localized NO release can be achieved from biomedical grade polymers doped with diazeniumdiolated dibutylhexanediamine (DBHD/N2O2) and poly(lactic-co-glycolic acid) (PLGA). In this study, the optimization of this chemistry to create film/patches that can be used to decrease microbial infection at wound sites is examined. Two polyurethanes with different water uptakes (Tecoflex SG-80A (6.2±0.7wt.%) and Tecophilic SP-60D-20 (22.5±1.1wt.%)) were doped with 25wt.% DBHD/N2O2 and 10wt.% of PLGA with various hydrolysis rates. Films prepared with the polymer that has the higher water uptake (SP-60D-20) were found to have higher NO release and for a longer duration than the polyurethane with the lower water uptake (SG-80A). The more hydrophilic polymer enhances the hydrolysis rate of the PLGA additive, thereby providing a more acidic environment that increases the rate of NO release from the NO donor. The optimal NO releasing and control SG-80A patches were then applied to scald burn wounds that were infected with Acinetobacter baumannii. The NO released from these patches applied to the wounds is shown to significantly reduce the A. baumannii infection after 24h (?4 log reduction). The NO release patches are also able to reduce the level of transforming growth factor-? in comparison to controls, which can enhance re-epithelialization, decrease scarring and reduce migration of bacteria. The combined DBHD/N2O2 and PLGA-doped polymer patches, which could be replaced periodically throughout the wound healing process, demonstrate the potential to reduce risk of bacterial infection and promote the overall wound healing process. PMID:24980058

  9. Numerical optimization of the interface shape at the VGF growth of semiconductor crystals in a traveling magnetic field

    NASA Astrophysics Data System (ADS)

    Frank-Rotsch, Ch.; Jockel, D.; Ziem, M.; Rudolph, P.

    2008-04-01

    For the first time the efficiency of a traveling magnetic field (TMF) generated inside a vertical gradient freeze (VGF) equipment of industrial scale is computed numerically. The TMF is induced in a combined heater-magnet module consisting of three coil segments operating with phase shift. A charge of 6 kg Ge in a cylindrical pBN container with diameter of 110 mm is taken as model arrangement. In the focus is the study of the interaction between the induced Lorentz force field and the buoyancy-driven convection to find out the optimal field parameters, like frequency and phase shift, for achievement of a slightly convex melt-solid interface and temperature stable growth regime. The flow patterns and interface morphology as functions of the H/ D aspect ratio ( H — melt height, D — melt diameter) in the course of the crystallization process are investigated. It turns out that there is only a narrow Lorentz force region at low frequencies that is able to control a laminar time-independent melt flow regime. The validity of the numerical results is supported by magnetic force measurements on a dummy within the heater-magnet module positioned inside the industrial VGF furnace "Kronos".

  10. Increase of SiC sublimation growth rate by optimizing of powder packaging

    NASA Astrophysics Data System (ADS)

    Wang, Xiaolin; Cai, Dang; Zhang, Hui

    2007-07-01

    In this paper, a comprehensive model for silicon carbide (SiC) sublimation crystal growth considering powder packaging is presented. This model is based on heat and mass transfer of porous powder charge with different sizes of the particle and accounts for induction heating, powder charge sublimation, vapor transport, and porosity evolution in a SiC sublimation crystal growth system. The mechanism of vapor transport is proposed by introducing a driving force arising from temperature difference between powder charge and seed in the growth system. Powder porosity evolution and sublimation rate variations are predicted based on vapor transport mechanism. Effects of powder geometry, such as particle sizes, volume and size ratios of different particles, and driving forces on the sublimation rate are studied. In addition, simulation results for powder sublimation with and without a central hole are presented. The results indicate that the sublimation rate can be increased by optimizing the powder packaging, or by creating a hole in the center of packed powder.

  11. Controlled growth of CNT in mesoporous AAO through optimized conditions for membrane preparation and CVD operation

    NASA Astrophysics Data System (ADS)

    Ciambelli, P.; Arurault, L.; Sarno, M.; Fontorbes, S.; Leone, C.; Datas, L.; Sannino, D.; Lenormand, P.; Le Blond Du Plouy, S.

    2011-07-01

    Anodic aluminium oxide (RAAO) membranes with a mesoporous structure were prepared under strictly controlling experimental process conditions, and physically and chemically characterized by a wide range of experimental techniques. Commercial anodic aluminium oxide (CAAO) membranes were also investigated for comparison. We demonstrated that RAAO membranes have lower content of both water and phosphorus and showed better porosity shape than CAAO. The RAAO membranes were used for template growth of carbon nanotubes (CNT) inside its pores by ethylene chemical vapour deposition (CVD) in the absence of a catalyst. A composite material, containing one nanotube for each channel, having the same length as the membrane thickness and an external diameter close to the diameter of the membrane holes, was obtained. Yield, selectivity and quality of CNTs in terms of diameter, length and arrangement (i.e. number of tubes for each channel) were optimized by investigating the effect of changing the experimental conditions for the CVD process. We showed that upon thermal treatment RAAO membranes were made up of crystallized allotropic alumina phases, which govern the subsequent CNT growth, because of their catalytic activity, likely due to their Lewis acidity. The strict control of experimental conditions for membrane preparation and CNT growth allowed us to enhance the carbon structural order, which is a critical requisite for CNT application as a substitute for copper in novel nano-interconnects.

  12. Controlled growth of CNT in mesoporous AAO through optimized conditions for membrane preparation and CVD operation.

    PubMed

    Ciambelli, P; Arurault, L; Sarno, M; Fontorbes, S; Leone, C; Datas, L; Sannino, D; Lenormand, P; Du Plouy, S Le Blond

    2011-07-01

    Anodic aluminium oxide (RAAO) membranes with a mesoporous structure were prepared under strictly controlling experimental process conditions, and physically and chemically characterized by a wide range of experimental techniques. Commercial anodic aluminium oxide (CAAO) membranes were also investigated for comparison. We demonstrated that RAAO membranes have lower content of both water and phosphorus and showed better porosity shape than CAAO. The RAAO membranes were used for template growth of carbon nanotubes (CNT) inside its pores by ethylene chemical vapour deposition (CVD) in the absence of a catalyst. A composite material, containing one nanotube for each channel, having the same length as the membrane thickness and an external diameter close to the diameter of the membrane holes, was obtained. Yield, selectivity and quality of CNTs in terms of diameter, length and arrangement (i.e. number of tubes for each channel) were optimized by investigating the effect of changing the experimental conditions for the CVD process. We showed that upon thermal treatment RAAO membranes were made up of crystallized allotropic alumina phases, which govern the subsequent CNT growth, because of their catalytic activity, likely due to their Lewis acidity. The strict control of experimental conditions for membrane preparation and CNT growth allowed us to enhance the carbon structural order, which is a critical requisite for CNT application as a substitute for copper in novel nano-interconnects. PMID:21576783

  13. Language and Verbal Memory in Individuals with a History of Autism Spectrum Disorders Who Have Achieved Optimal Outcomes

    PubMed Central

    Tyson, Katherine; Kelley, Elizabeth; Fein, Deborah; Orinstein, Alyssa; Troyb, Eva; Barton, Marianne; Eigsti, Inge-Marie; Naigles, Letitia; Schultz, Robert T.; Stevens, Michael; Helt, Molly; Rosenthal, Michael

    2013-01-01

    Some individuals who lose their autism spectrum disorder (ASD) diagnosis may continue to display subtle weaknesses in language. We examined language and verbal memory in 44 individuals with high-functioning autism (HFA), 34 individuals with “optimal outcomes” (OO) and 34 individuals with typical development (TD). The OO group scored in the average range or above on all measures and showed few differences from the TD group. The HFA group performed within the average range but showed significantly lower mean performance than the other groups on multiple language measures, even when controlling for VIQ. Results also indicate that OO individuals show strong language abilities in all areas tested, but that their language may show greater reliance on verbal memory. PMID:23982487

  14. Sensitivity Analysis and Optimization of Enclosure Radiation with Applications to Crystal Growth

    NASA Technical Reports Server (NTRS)

    Tiller, Michael M.

    1995-01-01

    In engineering, simulation software is often used as a convenient means for carrying out experiments to evaluate physical systems. The benefit of using simulations as 'numerical' experiments is that the experimental conditions can be easily modified and repeated at much lower cost than the comparable physical experiment. The goal of these experiments is to 'improve' the process or result of the experiment. In most cases, the computational experiments employ the same trial and error approach as their physical counterparts. When using this approach for complex systems, the cause and effect relationship of the system may never be fully understood and efficient strategies for improvement never utilized. However, it is possible when running simulations to accurately and efficiently determine the sensitivity of the system results with respect to simulation to accurately and efficiently determine the sensitivity of the system results with respect to simulation parameters (e.g., initial conditions, boundary conditions, and material properties) by manipulating the underlying computations. This results in a better understanding of the system dynamics and gives us efficient means to improve processing conditions. We begin by discussing the steps involved in performing simulations. Then we consider how sensitivity information about simulation results can be obtained and ways this information may be used to improve the process or result of the experiment. Next, we discuss optimization and the efficient algorithms which use sensitivity information. We draw on all this information to propose a generalized approach for integrating simulation and optimization, with an emphasis on software programming issues. After discussing our approach to simulation and optimization we consider an application involving crystal growth. This application is interesting because it includes radiative heat transfer. We discuss the computation of radiative new factors and the impact this mode of heat transfer has on our approach. Finally, we will demonstrate the results of our optimization.

  15. Nuclear Symbiosis - A Means to Achieve Sustainable Nuclear Growth while Limiting the Spread of Sensititive Nuclear Technology

    SciTech Connect

    David Shropshire

    2009-09-01

    Global growth of nuclear energy in the 21st century is creating new challenges to limit the spread of nuclear technology without hindering adoption in countries now considering nuclear power. Independent nuclear states desire autonomy over energy choices and seek energy independence. However, this independence comes with high costs for development of new indigenous fuel cycle capabilities. Nuclear supplier states and expert groups have proposed fuel supply assurance mechanisms such as fuel take-back services, international enrichment services and fuel banks in exchange for recipient state concessions on the development of sensitive technologies. Nuclear states are slow to accept any concessions to their rights under the Non-Proliferation Treaty. To date, decisions not to develop indigenous fuel cycle capabilities have been driven primarily by economics. However, additional incentives may be required to offset a nuclear state’s perceived loss of energy independence. This paper proposes alternative economic development incentives that could help countries decide to forgo development of sensitive nuclear technologies. The incentives are created through a nuclear-centered industrial complex with “symbiotic” links to indigenous economic opportunities. This paper also describes a practical tool called the “Nuclear Materials Exchange” for identifying these opportunities.

  16. Importance of growth temperature on achieving lattice-matched and strained InAlN/GaN heterostructure by plasma-assisted molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Jeganathan, K.; Shimizu, M.

    2014-09-01

    We investigate the role of growth temperature on the optimization of lattice-matched In0.17Al0.83N/GaN heterostructure and its structural evolutions along with electrical transport studies. The indium content gradually reduces with the increase of growth temperature and approaches lattice-matched with GaN having very smooth and high structural quality at 450°C. The InAlN layers grown at high growth temperature (480°C) retain very low Indium content of ˜ 4 % in which cracks are mushroomed due to tensile strain while above lattice matched (>17%) layers maintain crack-free compressive strain nature. The near lattice-matched heterostructure demonstrate a strong carrier confinement with very high two-dimensional sheet carrier density of ˜2.9 × 1013 cm-2 with the sheet resistance of ˜450 ?/? at room temperature as due to the manifestation of spontaneous polarization charge differences between InAlN and GaN layers.

  17. Importance of growth temperature on achieving lattice-matched and strained InAlN/GaN heterostructure by plasma-assisted molecular beam epitaxy

    SciTech Connect

    Jeganathan, K., E-mail: kjeganathan@yahoo.com [Centre for Nanoscience and Nanotechnology, School of Physics, Bharathidasan University, Tiruchirappalli-620 024, Tamil Nadu (India); Shimizu, M., E-mail: mitsu.shimizu@aist.go.jp [Advanced Power Electronics Research Center, National Institute of Advanced Industrial Science and Technology, Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan. (Japan)

    2014-09-15

    We investigate the role of growth temperature on the optimization of lattice-matched In{sub 0.17}Al{sub 0.83}N/GaN heterostructure and its structural evolutions along with electrical transport studies. The indium content gradually reduces with the increase of growth temperature and approaches lattice-matched with GaN having very smooth and high structural quality at 450ºC. The InAlN layers grown at high growth temperature (480ºC) retain very low Indium content of ? 4 % in which cracks are mushroomed due to tensile strain while above lattice matched (>17%) layers maintain crack-free compressive strain nature. The near lattice-matched heterostructure demonstrate a strong carrier confinement with very high two-dimensional sheet carrier density of ?2.9 × 10{sup 13} cm{sup ?2} with the sheet resistance of ?450 ?/? at room temperature as due to the manifestation of spontaneous polarization charge differences between InAlN and GaN layers.

  18. Effectiveness of setting numerical targets in the surgical training of residents: a trial to achieve an optimal balance.

    PubMed

    Komiya, Kiyoshi; Saito, Momoko; Sakurai, Yuika; Kojima, Hiromi; Takase, Kozo

    2014-01-01

    During the past 10 years, residency training in otorhinolaryngology-head and neck surgery (ORL-HNS) in Japan, especially at university hospitals, has emphasized subspecialization, resulting in insufficiencies in basic surgical techniques with an extreme bias toward acquiring subspecialty surgical case experience. To address this problem, we developed a target-oriented program intended to achieve a more balanced approach to surgical training and performed a 1-year trial of the program at the Jikei University School of Medicine. Fourteen residents with 1 to 4 years of ORL-HNS experience completed the trial. Each resident's competencies in six basic surgical procedures were assessed on the basis of the number of cases handled by the resident, and each resident's case selection bias after implementation of the target-oriented training was examined. The case selection bias in the trial group residents was reduced and their balance in case experience was shown to be improved in comparison with that in control group residents who were trained in the conventional way. In addition, opinion surveys of the participants and supervising otorhinolaryngologists (trainers) indicated that they felt that the new training system had been effective in improving the balance in case experience and improving motivation, and creating greater awareness of training goals and progress. PMID:24464636

  19. Feeding, growth, nutrition, and optimal interstage surveillance for infants with hypoplastic left heart syndrome.

    PubMed

    Hehir, David A; Cooper, David S; Walters, Elizabeth M; Ghanayem, Nancy S

    2011-12-01

    Improvement in operative survival of patients with hypoplastic left heart syndrome has led to increasing emphasis on prevention of interstage mortality. Many centres have improved interstage results through programmes of home monitoring following discharge after the Norwood (Stage 1) operation. Experience with heightened interstage surveillance has identified failure to thrive during infancy as a modifiable risk factor for this population, one that has been linked to concerning outcomes at subsequent palliative surgeries. Ensuring normal growth as an infant has thus become a priority of management of patients with functionally univentricular hearts. Herein, we review the existing evidence for best practices in interstage surveillance and optimal nutrition in infants with functionally univentricular hearts. In addition, we highlight data presented at HeartWeek 2011, from Cardiology 2011, the 15th Annual Update on Pediatric and Congenital Cardiovascular Disease, and the 11th Annual International Symposium on Congenital Heart Disease. PMID:22152530

  20. Growth and production optimization of tropane alkaloids in Datura stramonium cell suspension culture.

    PubMed

    Iranbakhsh, A R; Oshagi, M A; Ebadi, M

    2007-04-15

    Abstract: A number of physicochemical conditions such different concentration of glucose, sucrose, potassium nitrate, ammonium nitrate, calcium chloride and temperatures were tested to optimize growth and production of tropane alkaloids from Datura stramonium (Solanaceae) plants. Cell suspension from semi-clear calli of leave explants developed in MS medium containing kinetin (0.5 mg L(-1)) and NAA (2 mg L(-1)) hormones was used to measure biomass and total alkaloids and comparison of treatments. The results showed that 30 and 40 g L(-1) glucose led to the highest level of alkaloids and biomass productions, respectively. 20 and 40 g L(-1) sucrose concentrations resulted in order the most rates of alkaloids and biomass productions. The results showed that increasing of nitrate concentration led to the reduction of the alkaloids. The best concentration of potassium nitrate for the production of tropane alkaloids and biomass were in order 9.4 and 3.76 mM. Also it was evinced that the optimized concentration of ammonium nitrate for alkaloids production was 10.3 mM and for the biomass was 41.22 mM. The best concentration of calcium chloride for growth and production of the alkaloids was 7.92 mM. Testing different temperature specified that the best condition for production of the alkaloids was 20 degrees C whereas it was 25 degrees C for biomass production. The results of this study could be recommended to farmers involved in production of D. stramonium for tropain alkaloids at industrial and semi-industrial scales. PMID:19069922

  1. Heifer body weight gain and reproductive achievement in response to protein and energy supplementation while grazing dormant range forage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heifers grazing winter range require supplemental nutrients to compliment dormant forage to achieve optimal growth and performance. A study was conducted to evaluate nutritional environment and effect of different supplementation strategies for developing heifers grazing dormant winter range. Eigh...

  2. Real-time optical monitoring of microbial growth using optimal combination of light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Kobayashi, Ken-ichi; Yamada, Takeshi; Hiraishi, Akira; Nakauchi, Shigeki

    2012-12-01

    We developed a real-time optical monitoring system consisting of a monochrome complementary metal-oxide semiconductor (CMOS) camera and two light-emitting diodes (LEDs) with a constant temperature incubator for the rapid detection of microbial growth on solid media. As a target organism, we used Alicyclobacillus acidocaldarius, which is an acidophilic thermophilic endospore-forming bacterium able to survive in pasteurization processes and grow in acidic drink products such as apple juice. This bacterium was cultured on agar medium with a redox dye applied to improve detection sensitivity. On the basis of spectroscopic properties of the colony, medium, and LEDs, an optimal combination of two LED illuminations was selected to maximize the contrast between the colony and medium areas. We measured A. acidocaldarius and Escherichia coli at two different dilution levels using these two LEDs. From the results of time-course changes in the number of detected pixels in the detection images, a similar growth rate was estimated amongst the same species of microbes, regardless of the dilution level. This system has the ability to detect a colony of approximately 26 ?m in diameter in a detection image, and it can be interpreted that the size corresponds to less than 20 ?m diameter in visual inspection.

  3. Optimization of Plant Growth-Promoting Bacteria-Assisted Phytostabilization of Mine Tailings

    PubMed Central

    Grandlic, Christopher J.; Palmer, Michael W.; Maier, Raina M.

    2009-01-01

    Recent studies have indicated that plant growth-promoting bacteria (PGPB) can improve revegetation of arid mine tailings as measured by increased biomass production. The goals of the present study were first to evaluate how mode of application of known PGPB affects plant growth, and second to evaluate the effect of this inoculation on rhizosphere microbial community structure. PGPB application strategies investigated include preliminary surface sterilization of seeds (a common practice in phytoremediation trials) followed by a comparison of two application methods; immersion and alginate encapsulation. Results with two native desert plant species, Atriplex lentiformis and Buchloe dactyloides, suggest that seed surface sterilization prior to inoculation is not necessary to achieve beneficial effects of introduced PGPB. Both PGPB application techniques generally enhanced plant growth although results were both plant and PGPB specific. These results demonstrate that alginate encapsulation, which allows for long-term storage and easier application to seeds, is an effective way to inoculate PGPB. In addition, the influence of PGPB application on B. dactyloides rhizosphere community structure was evaluated using PCR-DGGE (denaturing gradient gel electrophoresis) analysis of bacterial DNA extracted from rhizosphere samples collected 75 d following planting. A comparative analysis of DGGE profiles was performed using canonical correspondence analysis (CCA). DGGE-CCA showed that rhizosphere community profiles from PGPB-inoculated treatments are significantly different from both uninoculated tailings rhizosphere profiles and profiles from the compost used to amend the tailings. Further, community profiles from B. dactyloides inoculated with the best performing PGPB (Arthro mix) were significantly different from two other PGPB tested. These results suggest that introduced PGPB have the potential to influence the development of the rhizosphere community structure found in plants grown in mine tailings. PMID:20161141

  4. Optimization of Plant Growth-Promoting Bacteria-Assisted Phytostabilization of Mine Tailings.

    PubMed

    Grandlic, Christopher J; Palmer, Michael W; Maier, Raina M

    2009-08-01

    Recent studies have indicated that plant growth-promoting bacteria (PGPB) can improve revegetation of arid mine tailings as measured by increased biomass production. The goals of the present study were first to evaluate how mode of application of known PGPB affects plant growth, and second to evaluate the effect of this inoculation on rhizosphere microbial community structure. PGPB application strategies investigated include preliminary surface sterilization of seeds (a common practice in phytoremediation trials) followed by a comparison of two application methods; immersion and alginate encapsulation. Results with two native desert plant species, Atriplex lentiformis and Buchloe dactyloides, suggest that seed surface sterilization prior to inoculation is not necessary to achieve beneficial effects of introduced PGPB. Both PGPB application techniques generally enhanced plant growth although results were both plant and PGPB specific. These results demonstrate that alginate encapsulation, which allows for long-term storage and easier application to seeds, is an effective way to inoculate PGPB. In addition, the influence of PGPB application on B. dactyloides rhizosphere community structure was evaluated using PCR-DGGE (denaturing gradient gel electrophoresis) analysis of bacterial DNA extracted from rhizosphere samples collected 75 d following planting. A comparative analysis of DGGE profiles was performed using canonical correspondence analysis (CCA). DGGE-CCA showed that rhizosphere community profiles from PGPB-inoculated treatments are significantly different from both uninoculated tailings rhizosphere profiles and profiles from the compost used to amend the tailings. Further, community profiles from B. dactyloides inoculated with the best performing PGPB (Arthro mix) were significantly different from two other PGPB tested. These results suggest that introduced PGPB have the potential to influence the development of the rhizosphere community structure found in plants grown in mine tailings. PMID:20161141

  5. Abstract --The growth of non-conventional renewable energies involves a new challenge for optimal network expansion. A better

    E-print Network

    Catholic University of Chile (Universidad Católica de Chile)

    and implementation of policies to develop Non-Conventional Renewable Energies (NCRE), they can be seen as a mechanism for the harmonious development of the expansion network. From the economic viewpoint, NCREs usually are considered will be achieved by an optimal expansion and efficient economic allocation is a complex task. This will depend

  6. Optimization of Methanotrophic Growth and Production of Poly(3-Hydroxybutyrate) in a High-Throughput Microbioreactor System.

    PubMed

    Sundstrom, Eric R; Criddle, Craig S

    2015-07-15

    Production of poly(3-hydroxybutyrate) (P3HB) from methane has economic and environmental advantages over production by agricultural feedstock. Identification of high-productivity strains and optimal growth conditions is critical to efficient conversion of methane to polymer. Current culture conditions, including serum bottles, shake flasks, and agar plates, are labor-intensive and therefore insufficient for systematic screening and isolation. Gas chromatography, the standard method for analysis of P3HB content in bacterial biomass, is also incompatible with high-throughput screening. Growth in aerated microtiter plates coupled with a 96-well Nile red flow-cytometric assay creates an integrated microbioreactor system for high-throughput growth and analysis of P3HB-producing methanotrophic cultures, eliminating the need for individual manipulation of experimental replicates. This system was tested in practice to conduct medium optimization for P3HB production in pure cultures of Methylocystis parvus OBBP. Optimization gave insight into unexpected interactions: for example, low calcium concentrations significantly enhanced P3HB production under nitrogen-limited conditions. Optimization of calcium and copper concentrations in the growth medium increased final P3HB content from 18.1% to 49.4% and P3HB concentration from 0.69 g/liter to 3.43 g/liter while reducing doubling time from 10.6 h to 8.6 h. The ability to culture and analyze thousands of replicates with high mass transfer in completely mixed culture promises to streamline medium optimization and allow the detection and isolation of highly productive strains. Applications for this system are numerous, encompassing analysis of biofuels and other lipid inclusions, as well as analysis of heterotrophic and photosynthetic systems. PMID:25956771

  7. The Application of Various Nonlinear Models to Describe Academic Growth Trajectories: An Empirical Analysis Using Four-Wave Longitudinal Achievement Data from a Large Urban School District

    ERIC Educational Resources Information Center

    Shin, Tacksoo

    2012-01-01

    This study introduced various nonlinear growth models, including the quadratic conventional polynomial model, the fractional polynomial model, the Sigmoid model, the growth model with negative exponential functions, the multidimensional scaling technique, and the unstructured growth curve model. It investigated which growth models effectively…

  8. Optimized N-phenyl- N?-(2-chloroethyl)ureas as potential antineoplastic agents: Synthesis and growth inhibition activity

    Microsoft Academic Search

    Emmanuel Moreau; Sébastien Fortin; Michel Desjardins; Jean L. C. Rousseau; Éric Petitclerc; René C.-Gaudreault

    2005-01-01

    In our ongoing research program aimed at the optimization of microtubule-self-assembly disrupting agents, we have prepared three series of phenylurea analogues (CEU), derived from N-(3-?-hydroxyalkyl or 4-?-hydroxyalkyl or 3-?-hydroxyalkynyl)-phenyl-N?-(2-chloroethyl)ureas. Most compounds exhibit potent growth inhibitory activity on human colon carcinoma HT-29, human skin melanoma M21, and human breast carcinoma MCF-7 tumor cell lines, with a GI50 ranging from 250nM to

  9. Exploring How Technology Growth Limits Impact Optimal Carbon dioxide Mitigation Pathways

    EPA Science Inventory

    Energy system optimization models prescribe the optimal mix of technologies and fuels for meeting energy demands over a time horizon, subject to energy supplies, demands, and other constraints. When optimizing, these models will, to the extent allowed, favor the least cost combin...

  10. Optimization and effects of different culture conditions on growth of Halomicronema hongdechloris – a filamentous cyanobacterium containing chlorophyll f

    PubMed Central

    Li, Yaqiong; Lin, Yuankui; Loughlin, Patrick C.; Chen, Min

    2014-01-01

    A chlorophyll f containing cyanobacterium, Halomicronema hongdechloris (H. hongdechloris) was isolated from a stromatolite cyanobacterial community. The extremely slow growth rate of H. hongdechloris has hindered research on this newly isolated cyanobacterium and the investigation of chlorophyll f-photosynthesis. Therefore, optimizing H. hongdechloris culture conditions has become an essential requirement for future research. This work investigated the effects of various culture conditions, essential nutrients and light environments to determine the optimal growth conditions for H. hongdechloris and the biosynthetic rate of chlorophyll f. Based on the total chlorophyll concentration, an optimal growth rate of 0.22 ± 0.02 day-1(doubling time: 3.1 ± 0.3 days) was observed when cells were grown under continuous illumination with far-red light with an intensity of 20 ?E at 32°C in modified K + ES seawater (pH 8.0) with additional nitrogen and phosphor supplements. High performance liquid chromatography on H. hongdechloris pigments confirmed that chlorophyll a is the major chlorophyll and chlorophyll f constitutes ~10% of the total chlorophyll from cells grown under far-red light. Fluorescence confocal image analysis demonstrated changes of photosynthetic membranes and the distribution of photopigments in response to different light conditions. The total photosynthetic oxygen evolution yield per cell showed no changes under different light conditions, which confirms the involvement of chlorophyll f in oxygenic photosynthesis. The implications of the presence of chlorophyll f in H. hongdechloris and its relationship with the ambient light environment are discussed. PMID:24616731

  11. Optimization of growth media for obtaining high-cell density cultures of halophilic archaea (family Halobacteriaceae) by response surface methodology.

    PubMed

    Manikandan, Muthu; Pasi?, Lejla; Kannan, Vijayaraghavan

    2009-06-01

    Optimization of media components for the growth and biomass production of Halobacterium salinarum VKMM 013 was carried out using response surface methodology. A second order quadratic model was estimated and media components were determined based on quadratic regression equation generated by model. These were 6.35 g L(-1) of KCl, 9.70 g L(-1) of MgSO(4), 13.38 g L(-1) of gelatin and 12.00 g L(-1) of soluble starch in nutrient broth supplemented with artificial seawater with 20% (w/v) of NaCl. In these optimal conditions, the obtained cell concentration of 0.746 g L(-1) dry weight was in agreement with the predicted cell concentration. The optimized media significantly shortened the time required for cell culture to reach the stationary phase while providing a nearly 2.4-fold increase in biomass production. Furthermore, in cell cultures of three other halophilic archaea the use of optimized media enhanced growth rate and provided high-cell density. PMID:19243935

  12. Optimizing cultivation strategies for robust algal growth and consequent removal of inorganic nutrients in pretreated livestock effluent.

    PubMed

    Kim, Hyun-Chul; Choi, Wook Jin; Ryu, Jun Hee; Maeng, Sung Kyu; Kim, Han Soo; Lee, Byung-Chan; Song, Kyung Guen

    2014-10-01

    Dilution was employed as a pretreatment strategy to increase light transmittance and decrease ammonia toxicity in piggery effluent prior to the cultivation of microalgae. The dilution effect was quantitatively determined based on both the maximum specific nutrient consumption rate and the maximum growth coefficient to minimize the usage of diluent. The biomass productivity of microalgae was also evaluated to select the best species among the five different candidates examined. A 20-fold dilution of piggery wastewater resulted in decreased chromaticity (584 mg Pt-Co L(-1)) and total nitrogen (76 mg L(-1)), on which the microalgae cultivation was more effective for an algal growth compared to the other dilution factors. If the initial cell concentration of Scenedesmus quadricauda increased, the production of biomass tended to improve. Robust growth and harvesting of S. quadricauda were achieved, and the associated consistent removal of inorganic nutrients was accomplished during the semi-continuous cultivation of the best species. PMID:25138601

  13. Inequality in Language Achievement Growth? An Investigation into the Impact of Pupil Socio-Ethnic Background and School Socio-Ethnic Composition

    ERIC Educational Resources Information Center

    Belfi, Barbara; Goos, Mieke; Pinxten, Maarten; Verhaeghe, Jean Pierre; Gielen, Sarah; De Fraine, Bieke; Van Damme, Jan

    2014-01-01

    This paper investigates how pupils' growth trajectories in three language domains (reading fluency, spelling, and reading comprehension) are related to their own socioeconomic and ethnic background and to the socioeconomic and ethnic composition of their primary school. Using multilevel piecewise growth curve analysis, the growth trajectories…

  14. Different Levels of Catabolite Repression Optimize Growth in Stable and Variable Environments

    E-print Network

    Zhang, Jianzhi

    in Computational Biology, Memorial Sloan Kettering Cancer Center, New York, New York, United States Abstract that are not required for growth in glucose. This ``generalist'' strategy reduces fitness in glucose, but allows faster, geometric mean growth rate; GO, gene ontological; HG, high glucose; LG, low glucose; Mal, maltose; Mal

  15. Planned Missing Designs to Optimize the Efficiency of Latent Growth Parameter Estimates

    ERIC Educational Resources Information Center

    Rhemtulla, Mijke; Jia, Fan; Wu, Wei; Little, Todd D.

    2014-01-01

    We examine the performance of planned missing (PM) designs for correlated latent growth curve models. Using simulated data from a model where latent growth curves are fitted to two constructs over five time points, we apply three kinds of planned missingness. The first is item-level planned missingness using a three-form design at each wave such…

  16. Optimization of plant growth-promoting bacteria-assisted phytostabilization of mine tailings

    Microsoft Academic Search

    Christopher J. Grandlic; Michael W. Palmer; Raina M. Maier

    2009-01-01

    Recent studies have indicated that plant growth-promoting bacteria (PGPB) can improve revegetation of arid mine tailings as measured by increased biomass production. The goals of the present study were first to evaluate how mode of application of known PGPB affects plant growth, and second to evaluate the effect of this inoculation on rhizosphere microbial community structure. PGPB application strategies investigated

  17. The Role of Ocean Dynamics in the Optimal Growth of Tropical SST Anomalies

    E-print Network

    Zanna, Laure

    The role of ocean dynamics in optimally exciting interannual variability of tropical sea surface temperature (SST) anomalies is investigated using an idealized-geometry ocean general circulation model. Initial temperature ...

  18. The Effects of Middle School Bullying and Victimization on Adjustment through High School: Growth Modeling of Achievement, School Attendance, and Disciplinary Trajectories

    ERIC Educational Resources Information Center

    Feldman, Marissa A.; Ojanen, Tiina; Gesten, Ellis L.; Smith-Schrandt, Heather; Brannick, Michael; Wienke Totura, Christine M.; Alexander, Lizette; Scanga, David; Brown, Ken

    2014-01-01

    The current 5-year longitudinal study examined the effects of middle school bullying and victimization on adolescent academic achievement, disciplinary referrals, and school attendance through high school (N = 2030; 1016 both boys and girls). Greater engagement in bullying behaviors was concurrently associated with lower achievement and school…

  19. Optimism

    PubMed Central

    Carver, Charles S.; Scheier, Michael F.; Segerstrom, Suzanne C.

    2010-01-01

    Optimism is an individual difference variable that reflects the extent to which people hold generalized favorable expectancies for their future. Higher levels of optimism have been related prospectively to better subjective well-being in times of adversity or difficulty (i.e., controlling for previous well-being). Consistent with such findings, optimism has been linked to higher levels of engagement coping and lower levels of avoidance, or disengagement, coping. There is evidence that optimism is associated with taking proactive steps to protect one's health, whereas pessimism is associated with health-damaging behaviors. Consistent with such findings, optimism is also related to indicators of better physical health. The energetic, task-focused approach that optimists take to goals also relates to benefits in the socioeconomic world. Some evidence suggests that optimism relates to more persistence in educational efforts and to higher later income. Optimists also appear to fare better than pessimists in relationships. Although there are instances in which optimism fails to convey an advantage, and instances in which it may convey a disadvantage, those instances are relatively rare. In sum, the behavioral patterns of optimists appear to provide models of living for others to learn from. PMID:20170998

  20. Engineering carbon nanostructures : development of novel aerogel-nanotube composites and optimization techniques for nanotube growth

    E-print Network

    Steiner, Stephen Alan, III

    2006-01-01

    Carbon aerogels offer several unique advantages which make them ideal for evaluating a metal's ability to catalyze nanotube growth, including in situ carbothermic reduction of oxidized nanoparticles to their catalytic ...

  1. Optimizing tubal epithelial cell growth promotes mouse embryo hatching in coculture

    Microsoft Academic Search

    Jonna Frasor; Richard Sherbahn; Barbara Soltes; Mary Wood Molo; Zvi Binor; Ewa Radwanska; Richard G. Rawlins

    1996-01-01

    Purpose: This study investigates the relationship between human tubal epithelial cell growth characteristics and mouse embryonic development to determine which cellular requirements should be preferentially provided in a coculture system.

  2. Analysis of environmental stress factors using an artificial growth system and plant fitness optimization.

    PubMed

    Lee, Meonghun; Yoe, Hyun

    2015-01-01

    The environment promotes evolution. Evolutionary processes represent environmental adaptations over long time scales; evolution of crop genomes is not inducible within the relatively short time span of a human generation. Extreme environmental conditions can accelerate evolution, but such conditions are often stress inducing and disruptive. Artificial growth systems can be used to induce and select genomic variation by changing external environmental conditions, thus, accelerating evolution. By using cloud computing and big-data analysis, we analyzed environmental stress factors for Pleurotus ostreatus by assessing, evaluating, and predicting information of the growth environment. Through the indexing of environmental stress, the growth environment can be precisely controlled and developed into a technology for improving crop quality and production. PMID:25874206

  3. Modeling and Design of Optimal Growth Media from Plant - Based Gas and Liquid Fluxes

    Microsoft Academic Search

    Scott B. Jones; Robert Heinse; Gail E. Bingham

    Design solutions for robust and optimal supply of water, nutrients, and gases within plant root media in micro- and reduced-gravity are essential for successful integration of plants as an important bioregenerative component of advanced life support systems. Many of the confounding and 'unknown' microgravity effects associated with previous plant research on Mir and on the International Space Station (ISS), may

  4. Relative efficiency of computing optimal growth by conjugate gradient and Davidon methods

    Microsoft Academic Search

    ELMO A. KELLER Jr; JATI K. SENGUPTA

    1973-01-01

    Two numerical algorithms are applied to non-linear planning models under optimal controls in order to test their sensitivity, convergence, and stability properties around the steady-state solution. In general, the Davidon algorithm is found to be more efficient in terms of faster convergence and the choice of the search direction parameter.

  5. Optimal life histories and food web position: linkages among somatic growth, reproductive investment, and mortality

    Microsoft Academic Search

    B. J. Shuter; N. P. Lester; J. LaRose; C. F. Purchase; K. Vascotto; G. Morgan; N. C. Collins; P. A. Abrams

    2005-01-01

    Life history variation among 60 Ontario populations of lake trout (Salvelinus namaycush), walleye (Sander vitreus), cisco (Coregonus artedii), and yellow perch (Perca flavescens) is presented and interpreted using a biphasic model of individual growth that specifically accounts for the significant shift in energy allocation that accompanies sexual maturity. We show that the constraints imposed on life history variation by the

  6. High-quality colloidal photonic crystals obtained by optimizing growth parameters in a vertical deposition technique

    Microsoft Academic Search

    Su-Lan Kuai; Xing-Fang Hu; Alain Haché; Vo-Van Truong

    2004-01-01

    High-quality polystyrene colloidal crystals were fabricated from aqueous solutions with a vertical deposition technique. The role of sphere size, volume fraction, relative humidity (RH), evaporation temperature and the final drying conditions on the film quality were investigated. We found that all those parameters must be taken into account in order to achieve highest quality for a given particle size. With

  7. Optimization of InAsSb/InGaAs strained-layer superlattice growth by metal-organic chemical vapor deposition for use in infrared emitters

    SciTech Connect

    Biefeld, R.M.; Baucom, K.C.; Follstaedt, D.M.; Kurtz, S.R.

    1994-08-01

    We have prepared InAsSb/InGaAs strained-layer superlattices (SLSs) by metal-organic chemical vapor deposition using a variety of growth conditions. Presence of an InGaAsSb interface layer was indicated by x-ray diffraction. This interface effect was minimized by optimizing the purge times, reactant flows, and growth conditions. The optimized growth conditions involved the use of low pressure, short purge times between the growth of the layers, and no reactant flow during the purges. Electron diffraction indicates that CuPt-type compositional ordering occurs in InAs{sub 1{minus}x}Sb{sub x} alloys and SLSs which explains an observed bandgap reduction from previously accepted alloy values.

  8. Development of a coupled model of a distributed hydrological model and a rice growth model for optimizing irrigation schedule

    NASA Astrophysics Data System (ADS)

    Tsujimoto, Kumiko; Homma, Koki; Koike, Toshio; Ohta, Tetsu

    2013-04-01

    A coupled model of a distributed hydrological model and a rice growth model was developed in this study. The distributed hydrological model used in this study is the Water and Energy Budget-based Distributed Hydrological Model (WEB-DHM) developed by Wang et al. (2009). This model includes a modified SiB2 (Simple Biosphere Model, Sellers et al., 1996) and the Geomorphology-Based Hydrological Model (GBHM) and thus it can physically calculate both water and energy fluxes. The rice growth model used in this study is the Simulation Model for Rice-Weather relations (SIMRIW) - rainfed developed by Homma et al. (2009). This is an updated version of the original SIMRIW (Horie et al., 1987) and can calculate rice growth by considering the yield reduction due to water stress. The purpose of the coupling is the integration of hydrology and crop science to develop a tool to support decision making 1) for determining the necessary agricultural water resources and 2) for allocating limited water resources to various sectors. The efficient water use and optimal water allocation in the agricultural sector are necessary to balance supply and demand of limited water resources. In addition, variations in available soil moisture are the main reasons of variations in rice yield. In our model, soil moisture and the Leaf Area Index (LAI) are calculated inside SIMRIW-rainfed so that these variables can be simulated dynamically and more precisely based on the rice than the more general calculations is the original WEB-DHM. At the same time by coupling SIMRIW-rainfed with WEB-DHM, lateral flow of soil water, increases in soil moisture and reduction of river discharge due to the irrigation, and its effects on the rice growth can be calculated. Agricultural information such as planting date, rice cultivar, fertilization amount are given in a fully distributed manner. The coupled model was validated using LAI and soil moisture in a small basin in western Cambodia (Sangker River Basin). This basin is mostly rainfed paddy so that irrigation scheme was firstly switched off. Several simulations with varying irrigation scheme were performed to determine the optimal irrigation schedule in this basin.

  9. Linking Student Achievement Growth to Professional Development Participation and Changes in Instruction: A Longitudinal Study of Elementary Students and Teachers in Title I Schools

    ERIC Educational Resources Information Center

    Desimone, Laura; Smith, Thomas M.; Phillips, Kristie J. R.

    2013-01-01

    Background/Context: Most reforms in elementary education rely on teacher learning and improved instruction to increase student learning. This study increases our understanding of which types of professional development effectively change teaching practice in ways that boost student achievement. Purpose/Objective/Research Question/Focus of Study:…

  10. Low optimal temperatures for food conversion and growth in the big-headed turtle, Platysternon megacephalum

    Microsoft Academic Search

    Yong-Pu Zhang; Wei-Guo Du; Jian-Wei Shen; Lin Shu

    2009-01-01

    We held juvenile big-headed turtles, Platysternon megacephalum, from eastern China, at temperatures from 20 to 29.4 °C to determine effects on feeding, growth and food conversion. Food intake increased significantly from 20 to 22.4 °C, remained high until 27.1 °C, and then decreased dramatically at 29.4 °C. Digestive efficiency for energy decreased as temperature increased, whereas the digestive efficiency of protein increased from 20 to 25 °C, and

  11. Optimization of ion assist beam deposition of magnesium oxide template films during initial nucleation and growth

    SciTech Connect

    Groves, James R [Los Alamos National Laboratory; Matias, Vladimir [Los Alamos National Laboratory; Stan, Liliana [Los Alamos National Laboratory; De Paula, Raymond F [Los Alamos National Laboratory; Hammond, Robert H [STANFORD UNIV.; Clemens, Bruce M [STANFOED UNIV.

    2010-01-01

    Recent efforts in investigating the mechanism of ion beam assisted deposition (IBAD) of biaxially textured thin films of magnesium oxide (MgO) template layers have shown that the texture develops suddenly during the initial 2 nm of deposition. To help understand and tune the behavior during this initial stage, we pre-deposited thin layers of MgO with no ion assist prior to IBAD growth of MgO. We found that biaxial texture develops for pre-deposited thicknesses < 2 nm, and that the thinnest layer tested, at 1 nm, resulted in the best qualitative RHEED image, indicative of good biaxial texture development. The texture developed during IBAD growth on the 1.5 nm pre-deposited layer is slightly worse and IBAD growth on the 2 nm pre-deposited layer produces a fiber texture. Application of these layers on an Al{sub 2}O{sub 3} starting surface, which has been shown to impede texture development, improves the overall quality of the IBAD MgO and has some of the characteristics of a biaxially texture RHEED pattern. It is suggested that the use of thin (<2 nm) pre-deposited layers may eliminate the need for bed layers like Si{sub 3}N{sub 4} and Y{sub 2}O{sub 3} that are currently thought to be required for proper biaxial texture development in IBAD MgO.

  12. Optimization of peptides that target human thymidylate synthase to inhibit ovarian cancer cell growth.

    PubMed

    Pelà, Michela; Saxena, Puneet; Luciani, Rosaria; Santucci, Matteo; Ferrari, Stefania; Marverti, Gaetano; Marraccini, Chiara; Martello, Andrea; Pirondi, Silvia; Genovese, Filippo; Salvadori, Severo; D'Arca, Domenico; Ponterini, Glauco; Costi, Maria Paola; Guerrini, Remo

    2014-02-27

    Thymidylate synthase (TS) is a target for pemetrexed and the prodrug 5-fluorouracil (5-FU) that inhibit the protein by binding at its active site. Prolonged administration of these drugs causes TS overexpression, leading to drug resistance. The peptide lead, LR (LSCQLYQR), allosterically stabilizes the inactive form of the protein and inhibits ovarian cancer (OC) cell growth with stable TS and decreased dihydrofolate reductase (DHFR) expression. To improve TS inhibition and the anticancer effect, we have developed 35 peptides by modifying the lead. The d-glutamine-modified peptide displayed the best inhibition of cisplatin-sensitive and -resistant OC cell growth, was more active than LR and 5-FU, and showed a TS/DHFR expression pattern similar to LR. Circular dichroism spectroscopy and molecular dynamics studies provided a molecular-level rationale for the differences in structural preferences and the enzyme inhibitory activities. By combining target inhibition studies and the modulation pattern of associated proteins, this work avenues a concept to develop more specific inhibitors of OC cell growth and drug leads. PMID:24450514

  13. Growth optimization and optical properties of AlGaNAs alloys

    SciTech Connect

    Kolhatkar, Gitanjali; Boucherif, Abderraouf; Aimez, Vincent; Arès, Richard, E-mail: Richard.Ares@USherbrooke.ca [Institut interdisciplinaire d'innovation technologique (3IT), Université de Sherbrooke, 3000, boul. Université, J1K 0A5 Sherbrooke, Québec (Canada); Laboratoire Nanotechnologies Nanosystèmes (LN2)- CNRS UMI-3463, Université de Sherbrooke, 3000 Boulevard Université, Sherbrooke J1K OA5, Québec (Canada); Valdivia, Christopher E.; Wallace, Steven G.; Fafard, Simon [Cyrium Technologies Inc., 50 Hines Road, K2K 2M5 Ottawa, Ontario (Canada)

    2014-04-28

    The effect of Al on the surface morphology of chemical beam epitaxy grown AlGaNAs alloys is studied. Pits attributed to N clustering appearing on the dilute nitride surface become smaller, denser, and more uniformly distributed in the presence of Al. This reveals that the introduction of Al results in more homogenous N atoms spatial distribution. A growth temperature study reveals the formation of 3D structures at high temperature due to phase separation. The density of these structures decreases, while their diameter and height increase when the temperature is raised from 380?°C to 565?°C. At growth temperatures in the 380–420?°C range, the phase separation is suppressed and the growth mode is 2D. At 420?°C, the N incorporation is also maximized, making it the optimum temperature. The absorption coefficient and the bandgap of AlGaNAs alloys are extracted from transmittance measurement. A good agreement is obtained between the experimentally measured bandgap and the theoretical values calculated using the band anticrossing model. A bandgap as low as 1.22?eV was reached using Al and N concentrations of ?15% and ?3.4%, respectively.

  14. Optimization of light for growth, photosynthesis, and hydrocarbon production by the colonial microalga Botryococcus braunii BOT-22.

    PubMed

    Sakamoto, Kohei; Baba, Masato; Suzuki, Iwane; Watanabe, Makoto M; Shiraiwa, Yoshihiro

    2012-04-01

    Optimization of the light conditions for biofuel production by the microalga Botryococcus braunii BOT-22 (race B) was performed using monochromatic red light. The lipid and sugar contents were approximately 40% and 20-30% of the cell dry weight, respectively, and about half of the lipids were liquid hydrocarbons. The half-saturation intensities for the production rate of lipids, hydrocarbons, and sugars were 63, 49, and 44?molm(-2)s(-1), respectively. Fluorescence microscopic images of Nile Red-stained cells showed an increased number of intracellular neutral lipid granules due to increased light intensity. After 16days of incubation in the dark, lipid and sugar, but not hydrocarbon content decreased. Growth, metabolite production, and photosynthesis were saturated at 100, 200 and 1000?molm(-2)s(-1), respectively. These results indicate that photosynthetically captured energy is not used efficiently for metabolite production; thus, improvements in metabolic regulation may increase hydrocarbon production. PMID:22334002

  15. The integration of Dow's fire and explosion index (F&EI) into process design and optimization to achieve inherently safer design

    Microsoft Academic Search

    Jaffee Suardin; M. Sam Mannan; Mahmoud El-Halwagi

    2007-01-01

    For the processing industries, it is critically to have an economically optimum and inherently safer design and operation. The basic concept is to achieve the best design based on technical and business performance criteria while performing within acceptable safety levels. Commonly, safety is examined and incorporated typically as an after-thought to design. Therefore, systematic and structured procedure for integrating safety

  16. Combined silencing of K-ras and Akt2 oncogenes achieves synergistic effects in inhibiting pancreatic cancer cell growth in vitro and in vivo

    Microsoft Academic Search

    X H Shi; Z Y Liang; X Y Ren; T H Liu

    2009-01-01

    Cancer is a complex disease involving multiple oncogenes with diverse actions. Inhibiting only one oncogene is unlikely to eliminate the malignancy of cancer cells. The goal of this study was to investigate whether synergistic effects can be achieved by combined silencing of two oncogenes, K-ras and Akt2, which are key players in the Ras\\/MAPK and PI3K\\/Akt signaling pathways. The pancreatic

  17. Reading Achievement Across Three Language Groups: Growth Estimates for Overall Reading and Reading Subskills Obtained With the Early Childhood Longitudinal Survey

    Microsoft Academic Search

    Greg Roberts; Sarojani S. Mohammed; Sharon Vaughn

    2010-01-01

    This study estimated normative reading trajectories for the population of English-proficient language minority students attending U.S. public elementary schools. Achievement of English-language learners (ELLs) was evaluated in terms of native English speakers' progress, and estimates were adjusted for the effects of socioeconomic status (SES). The ELL group was disaggregated into native Spanish speakers and native speakers of Asian languages. Multilevel

  18. The Moderating Role of Different Sources of Perceived Social Support on the Dispositional Optimism— Posttraumatic Growth Relationship in Postoperative Breast Cancer Patients

    Microsoft Academic Search

    Özlem Bozo; Elçin Gündo?du; Canan Büyüka?ik-Çolak

    2009-01-01

    The purpose of this study was to investigate the dispositional optimism—posttraumatic growth (PTG) relationship in postoperative breast cancer patients and to examine if perceived social support moderates this relationship. The study was conducted with 104 women undergoing postoperative chemotherapy treatment or coming to the hospital for their routine controls. Hierarchical multiple regression analyses indicated that breast cancer survivors high on

  19. Microbial-enzymatic-hybrid biological fuel cell with optimized growth conditions for Shewanella oneidensis DSP-10.

    PubMed

    Roy, Jared N; Luckarift, Heather R; Sizemore, Susan R; Farrington, Karen E; Lau, Carolin; Johnson, Glenn R; Atanassov, Plamen

    2013-07-10

    In this work we present a biological fuel cell fabricated by combining a Shewanella oneidensis microbial anode and a laccase-modified air-breathing cathode. This concept is devised as an extension to traditional biochemical methods by incorporating diverse biological catalysts with the aim of powering small devices. In preparing the biological fuel cell anode, novel hierarchical-structured architectures and biofilm configurations were investigated. A method for creating an artificial biofilm based on encapsulating microorganisms in a porous, thin film of silica was compared with S. oneidensis biofilms that were allowed to colonize naturally. Results indicate comparable current and power densities for artificial and natural biofilm formations, based on growth characteristics. As a result, this work describes methods for creating controllable and reproducible bio-anodes and demonstrates the versatility of hybrid biological fuel cells. PMID:23769313

  20. Optimization of adiponectin-derived peptides for inhibition of cancer cell growth and signaling.

    PubMed

    Otvos, Laszlo; Kovalszky, Ilona; Olah, Julia; Coroniti, Roberta; Knappe, Daniel; Nollmann, Friederike I; Hoffmann, Ralf; Wade, John D; Lovas, Sandor; Surmacz, Eva

    2015-05-01

    Adiponectin, an adipose tissue-excreted adipokine plays protective roles in metabolic and cardiovascular diseases and exerts anti-cancer activities, partially by interfering with leptin-induced signaling. Previously we identified the active site in the adiponectin protein, and generated both a nanomolar monomeric agonist of the adiponectin receptor (10-mer ADP355) and an antagonist (8-mer ADP400) to modulate various adiponectin receptor-mediated cellular functions. As physiologically circulating adiponectin forms multimeric complexes, we also generated an agonist dimer with improved biodistribution and in vitro efficacy. In the current report, we attempted to optimize the monomeric agonist structure. Neither extension of the peptide up to 14-mer analogs nor reinstallation of native residues in permissible positions enhanced significantly the activity profile. The only substitutions that resulted in 5-10-fold improved agonistic activity were the replacement of turn-forming Gly4 and Tyr7 residues with Pro and Hyp, respectively, yielding the more active native ?-sheet structure. All peptides retained good stability in human serum exhibiting half-lives >2 h. The cellular efficacy and stability rankings among the peptides followed expected structure-activity relationship trends. To investigate whether simultaneous activation of adiponectin pathways and inhibition of leptin-induced signals can result in cytostatic and anti-oncogenic signal transduction processes, we developed a chimera of the leptin receptor antagonist peptide Allo-aca (placed to the N-terminus) and ADP355 (at the C-terminus). The in vitro anti-tumor activity and intracellular signaling of the chimera were dominated by the more active Allo-aca component. The ADP355 part, however, reversed unfavorable in vivo metabolic effects of the leptin receptor antagonist. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 156-166, 2015. PMID:25683126

  1. Planting geometry to optimize growth and productivity in faba bean (Vicia faba L.) and soil fertility.

    PubMed

    Singh, A K; Bhatt, B P; Sundaram, P K; Gupta, A K; Singh, Deepak

    2013-01-01

    Faba bean (Vicia faba L.) responses to alteration of its ambient environment leads to certain modification in the crop phenology, yield attributes and economic yield. To know the extent and pattern of response by faba bean to alterations, a two year field experimentation was carried out with two crop establishment methods (i) flatbed planting (ii) raised bed planting, four planting geometry (i) 30 x 20 cm(ii) 30 x 30 cm (iii) 30 x 45 cm and (iv) 45X45cm and three seeding depth. All the treatment (two crop establishment methods, four planting geometry and three seeding depth) were combined together consisting twenty four treatments, were organized in factorial experiment in complete randomized block design (CRBD) with three replications. Data were recorded on growth and development; yield attributes and yield. Soil analysis was done and finally statistical tool were applied to come in to valid conclusion. Raised bed planting proves superior over flatbed in case of seed yield. Square planting architect with 30 cm apart prove better (3690.9 kg ha(-1)) than other tested planting geometry. Seeding at 10 cm depth showed, significant improvement in seed yield per plant and per ha over other two tested seeding depth. Phosphorus availability was significantly higher in raised bed planting (36.9 kg ha(-1)). However, available K (kg ha(-1)) was significantly influenced by planting geometry and seeding depth. It was maximum (155.2 kg ha(-1)) with 30 x 45 cm plant geometry, proved significantly higher than 30 x 20 cm and 30 x 30 cm and at par with 45 x 45 cm planting. PMID:24006817

  2. Optimization of culture conditions to support undifferentiated growth of human embryonic stem cells.

    PubMed

    Lai, Dongmei; Cheng, Weiwei; Liu, Te; Jiang, Lizheng; Liu, Tianjin; Huang, Qin; Guo, Lihe

    2010-06-01

    Human embryonic stem cells (hESCs) are usually maintained in an undifferentiated state by coculture with mitomycin C-treated mouse embryonic fibroblasts (MEFs) as feeder cells in the presence of animal sera such as fetal bovine serum (FBS). Here, we use primary human amnion epithelial cells (hAECs) as feeder cells and human umbilical cord blood serum (CBS) as a replacement for FBS to support undifferentiated growth of hESCs. The 5 approximately 10-fold higher expression levels of ES cell markers including FGF, Oct-4, Nanog, Sox-2, Rex, and TERT were found in hESCs grown on hAECs compared with that on MEFs as measured by quantitative real-time polymerase chain reaction (PCR). By immunofluorescence, the expresisons of Oct-4 and Nanog is also higher in cells grown on hAECs than those on MEFs. Importantly, the ES cells grown on hAECs exhibit normal karyotypes on passage 25, thus ruling out the possibility of transformation. Using flow cytometry analysis, we show that both the ES cells grown on hAECs and MEFs have the same cell cycle distribution pattern. Further, hESCs cultured on hAECs for at least 20 passages could differentiate into three germ layers via teratoma formation. In addition, chromatin immunoprecipitation assay revealed that histone H3 is highly acetylated, and H3 lysine (K) 4 is hypermethylated at the Nanog locus and the Oct-4 locus in hESCs grown on hAECs. Conversely, hESCs grown on MEFs show histone deacetylation and H3-K4 demethylation. Taken together, these results suggest that hAECs supplemented with 10% CBS are suitable for hESC culture, and that this method may prove to be valuable for use in future regenerative therapies. PMID:20698772

  3. Elemental Economy: microbial strategies for optimizing growth in the face of nutrient limitation

    PubMed Central

    Merchant, Sabeeha S.; Helmann, John D.

    2014-01-01

    Microorganisms play a dominant role in the biogeochemical cycling of nutrients. They are rightly praised for their facility at fixing both carbon and nitrogen into organic matter, and microbial driven processes have tangibly altered the chemical composition of the biosphere and its surrounding atmosphere. Despite their prodigious capacity for molecular transformations, microorganisms are powerless in the face of the immutability of the elements. Limitations for specific elements, either fleeting or persisting over eons, have left an indelible trace on microbial genomes, physiology, and their very atomic composition. We here review the impact of elemental limitation on microbes, with a focus on selected genetic model systems and representative microbes from the ocean ecosystem. Evolutionary adaptations that enhance growth in the face of persistent or recurrent elemental limitations are evident from genome and proteome analyses. These range from the extreme (such as dispensing with a requirement for a hard to obtain element) to the extremely subtle (changes in protein amino acid sequences that slightly, but significantly, reduce cellular carbon, nitrogen, or sulfur demand). One near universal adaptation is the development of sophisticated acclimation programs by which cells adjust their chemical composition in response to a changing environment. When specific elements become limiting, acclimation typically begins with an increased commitment to acquisition and a concomitant mobilization of stored resources. If elemental limitation persists, the cell implements austerity measures including elemental-sparing and elemental-recycling. Insights into these fundamental cellular properties have emerged from studies at many different levels; including ecology, biological oceanography, biogeochemistry, molecular genetics, genomics, and microbial physiology. Here, we present a synthesis of these diverse studies and attempt to discern some overarching themes. PMID:22633059

  4. Production of human lysozyme in biofilm reactor and optimization of growth parameters of Kluyveromyces lactis K7.

    PubMed

    Ercan, Duygu; Demirci, Ali

    2013-07-01

    Lysozyme (1,4-?-N-acetylmuramidase) is a lytic enzyme, which degrades the bacterial cell wall. Lysozyme has been of interest in medicine, cosmetics, and food industries because of its anti-bactericidal effect. Kluyveromyces lactis K7 is a genetically modified organism that expresses human lysozyme. There is a need to improve the human lysozyme production by K. lactis K7 to make the human lysozyme more affordable. Biofilm reactor provides high biomass by including a solid support, which microorganisms grow around and within. Therefore, the aim of this study was to produce the human lysozyme in biofilm reactor and optimize the growth conditions of K. lactis K7 for the human lysozyme production in biofilm reactor with plastic composite support (PCS). The PCS, which includes polypropylene, soybean hull, soybean flour, bovine albumin, and salts, was selected based on biofilm formation on PCS (CFU/g), human lysozyme production (U/ml), and absorption of lysozyme inside the support. To find the optimum combination of growth parameters, a three-factor Box-Behnken design of response surface method was used. The results suggested that the optimum conditions for biomass and lysozyme productions were different (27 °C, pH 6, 1.33 vvm for biomass production; 25 °C, pH 4, no aeration for lysozyme production). Then, different pH and aeration shift strategies were tested to increase the biomass at the first step and then secrete the lysozyme after the shift. As a result, the lysozyme production amount (141 U/ml) at 25 °C without pH and aeration control was significantly higher than the lysozyme amount at evaluated pH and aeration shift conditions (p?

  5. Daily energy balance in growth hormone receptor/binding protein (GHR?/?) gene-disrupted mice is achieved through an increase in dark-phase energy efficiency

    PubMed Central

    Longo, Kenneth A.; Berryman, Darlene E.; Kelder, Bruce; Charoenthongtrakul, Soratree; DiStefano, Peter S.; Geddes, Brad J.; Kopchick, John

    2009-01-01

    The goal of this study was to examine factors that contribute to energy balance in female GHR ?/? mice. We measured energy intake, energy expenditure (EE), fuel utilization, body mass (Mb) changes and physical activity in 17 month-old female GHR ?/? mice and their age-matched wild type littermates. The GHR ?/? mice were smaller, consumed more food per unit Mb, had greater EE per unit Mb and had an increase in 24-h EE/Mb that was similar to the increase in their surface-area-to-volume ratio. Locomotor activity (LMA) was reduced in the GHR ?/? mice, but the energetic cost associated with their LMA was greater than in wild type controls. Furthermore, Mb and LMA were independent explanatory covariates of most of the variance in EE, and when adjusted for Mb and LMA, the GHR ?/? mice had higher EE during both the light and dark phases of the daily cycle. Respiratory quotient was lower in GHR ?/? mice during the light phase, which indicated a greater utilization of lipid relative to carbohydrate in these mice. Additionally, GHR ?/? mice had higher ratios of caloric intake to EE at several intervals during the dark phase, and this effect was greater and more sustained in the final three hours of the dark phase. Therefore, we conclude that GHR ?/? mice are able to overcome the substantial energetic challenges of dwarfism through several mechanisms that promote stable Mb. Relative to wild type mice, the GHR ?/? mice consumed more calories per unit Mb, which offset the disproportionate increase in their daily energy expenditure. While GHR ?/? mice oxidized a greater proportion of lipid during the light phase in order to meet their energy requirements, they achieved greater energy efficiency and storage during the dark phase through a combination of higher energy consumption and lower LMA. PMID:19747867

  6. Large-scale, surfactant-free, hydrothermal synthesis of lithium aluminate nanorods: optimization of parameters and investigation of growth mechanism.

    PubMed

    Joshi, Upendra A; Lee, Jae Sung

    2007-04-16

    Lithium aluminate nanorods were successfully synthesized from Al2O3 nanoparticles and lithium hydroxide by a simple, large-scale hydrothermal process without any surfactant or template. The various reaction parameters were optimized to achieve the maximum yield. The as-obtained nanorods had orthorhombic beta-lithium aluminate structure with edges in the range of 40-200 nm and lengths of 1-2 mum confirmed by SEM, TEM, XRD, and NMR. Upon calcination at 1273 K for 12 h it transformed to gamma-lithium aluminate, yet maintained the initial morphology, demonstrating the thermal stability. The ratio of lithium hydroxide to aluminum oxide showed a significant effect on the morphology as Li/Al = 1 gives "microroses", whereas Li/Al = 3 and Li/Al = 15 gave "microbricks" and "nanorods", respectively. Investigation of the mechanism showed that the nanorods were formed via a "rolling-up" mechanism. As we used all-inorganic raw materials and a simple synthetic procedure under mild conditions, the scale-up of this process for large-scale production should be very easy. PMID:17371012

  7. Optimal contrast enhancement achieved by the synthetic method for bone and tissue separation based on a dual-energy radiographic system

    NASA Astrophysics Data System (ADS)

    Kim, D.-H.; Lee, Y.-J.; Jeon, P.-H.; Jo, B.-D.; Kim, H.-J.

    2013-07-01

    In dual-energy digital radiography (DEDR), the energy subtraction and equivalent thickness methods have been used for detecting thorax lesions. However, the image contrast of the energy subtraction method is low in comparion with that of the equivalent thickness and synthetic methods. Therefore, we applied the equivalent thickness and synthetic methods to material separation to enhance the bone and tissue contrast, and these results were compared with the results of the energy subtraction method in a chest DEDR system. The purpose of this work was to evaluate the image quality of the energy subtraction, equivalent thickness, and synthetic methods. In the energy subtraction method, the optimal weighting factors were selected for bone and tissue visualization, respectively. The equivalent thickness was obtained with a calibration procedure by using combinations of aluminum and polymethyl methacrylate (PMMA) blocks. The synthetic images were acquired with the known equation from the results of the equivalent thickness method. According to these results, the contrast-to-noise-ratio (CNR) values using the equivalent thickness and synthetic methods were improved than those obtained with the energy subtraction method in both aluminum and PMMA enhancement trial. In a cylindrical phantom study, the equivalent thickness and the synthetic method improved the contrast better than energy subtraction method. The synthetic method supplements the air shadows shown in the equivalent thickness method. We compared the enhanced images of bone and tissue with the energy subtraction, equivalent thickness, and synthetic methods. Our results showed that the effects of the synthetic method can improve the image contrast on both bone and tissue and overcome the bone shadows in tissue images in a DEDR system.

  8. Leaf area ratio and net assimilation rate of 24 wild species differing in relative growth rate

    Microsoft Academic Search

    Hendrik Poorter; Carlo Remkes

    1990-01-01

    Which factors cause fast-growing plant species to achieve a higher relative growth rate than slow-growing ones? To answer this question 24 wild species were grown from seed in a growth chamber under conditions of optimal nutrient supply and a growth analysis was carried out. Mean relative growth rate, corrected for possible ontogenetic drift, ranged from 113 to 356 mg g-1

  9. Characterization and Optimization of Atomic Hydrogen Cleaning of InP Surface for Selective Molecular Beam Epitaxial Growth of InGaAs Quantum Structure Arrays

    Microsoft Academic Search

    Tsutomu Muranaka; Chao Jiang; Akira Ito; Hideki Hasegawa

    2001-01-01

    An oxide removal process for InP surface using atomic hydrogen cleaning was characterized and optimized for use in the selective molecular beam epitaxial (MBE) growth of InGaAs quantum structures. In-situ X-ray photoelectron spectroscopy (XPS), reflection high energy electron diffraction (RHEED), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques were used. Detailed XPS measurements clarified the effects of atomic

  10. Growth optimization and characterization of lattice-matched Al 0.82In 0.18N optical confinement layer for edge emitting nitride laser diodes

    NASA Astrophysics Data System (ADS)

    Kim-Chauveau, H.; Frayssinet, E.; Damilano, B.; De Mierry, P.; Bodiou, L.; Nguyen, L.; Vennéguès, P.; Chauveau, J.-M.; Cordier, Y.; Duboz, J. Y.; Charash, R.; Vajpeyi, A.; Lamy, J.-M.; Akhter, M.; Maaskant, P. P.; Corbett, B.; Hangleiter, A.; Wieck, A.

    2012-01-01

    We present the growth optimization and the doping by the metal organic chemical vapor deposition of lattice-matched Al 0.82In 0.18N bottom optical confinement layers for edge emitting laser diodes. Due to the increasing size and density of V-shaped defects in Al 1- xIn xN with increasing thickness, we have designed an Al 1- xIn xN/GaN multilayer structure by optimizing the growth and thickness of the GaN interlayer. The Al 1- xIn xN and GaN interlayers in the multilayer structure were both doped using the same SiH 4 flow, while the Si levels in both layers were found to be significantly different by SIMS. The optimized 8×(Al 0.82In 0.18N/GaN=54/6 nm) multilayer structures grown on free-standing GaN substrates were characterized by high resolution X-ray diffraction, atomic force microscopy and transmission electron microscopy, along with the in-situ measurements of stress evolution during growth. Finally, lasing was obtained from the UV (394 nm) to blue (436 nm) wavelengths, in electrically injected, edge-emitting, cleaved-facet laser diodes with 480 nm thick Si-doped Al 1- xIn xN/GaN multilayers as bottom waveguide claddings.

  11. Acta Cryst. (1994). D50, 572-590 Quantitative Analysis in the Characterization and Optimization of Protein Crystal Growth

    E-print Network

    Yin, Y. Whitney

    1994-01-01

    of Protein Crystal Growth BY CHARLESW. CARTERJR AND YUHUI YIN Department of Biochemistry and Biophysics 21 October 1993; accepted 31 January 1994) Abstract Protein crystal growth often depends on the combi of biochemical parameters, such as lig- ands and pH. Tests of the reproducibility of crystal growth experiments

  12. Stochastic dynamic optimization approach for revegetation of reclaimed mine soils under uncertain weather regime

    Microsoft Academic Search

    Mustafa

    1989-01-01

    This study presents a comprehensive physically based stochastic dynamic optimization model to assist planners in making decisions concerning mine soil depths and soil mixture ratios required to achieve successful revegetation of mine lands at different probability levels of success, subject to an uncertain weather regime. A perennial grass growth model was modified and validated for predicting vegetation growth in reclaimed

  13. Thin sheets achieve optimal wrapping of liquids

    NASA Astrophysics Data System (ADS)

    Paulsen, Joseph; Démery, Vincent; Davidovitch, Benny; Santangelo, Christian; Russell, Thomas; Menon, Narayanan

    2015-03-01

    A liquid drop can wrap itself in a sheet using capillary forces [Py et al., PRL 98, 2007]. However, the efficiency of ``capillary origami'' at covering the surface of a drop is hampered by the mechanical cost of bending the sheet. Thinner sheets deform more readily by forming small-scale wrinkles and stress-focussing patterns, but it is unclear how coverage efficiency competes with mechanical cost as thickness is decreased, and what wrapping shapes will emerge. We place a thin (~ 100 nm) polymer film on a drop whose volume is gradually decreased so that the sheet covers an increasing fraction of its surface. The sheet exhibits a complex sequence of axisymmetric and polygonal partially- and fully- wrapped shapes. Remarkably, the progression appears independent of mechanical properties. The gross shape, which neglects small-scale features, is correctly predicted by a simple geometric approach wherein the exposed area is minimized. Thus, simply using a thin enough sheet results in maximal coverage.

  14. MOVPE growth and optimization of GRINSCH single quantum well AlGaAs\\/GaAs laser diodes

    Microsoft Academic Search

    Rajesh K. Bag; Renu Tyagi; T. Haldar; Mahavir Singh; Premila Mohan; Puspashree Mishra; R. Muralidharan

    2007-01-01

    In the present paper we report the MOVPE growth of GaAs\\/AlGaAs graded-index separate confinement heterostructure (GRINSCH) single quantum well (SQW) laser structure at relatively low temperature. Low temperature growth was possible by controlling various growth parameters as well as external sources of oxygen contamination. The grown structures were characterized by photoluminescence (PL) and high resolution X-ray diffraction (HRXRD) technique. Stripe

  15. Optimal Flow.

    ERIC Educational Resources Information Center

    Norman, Donald A.

    1996-01-01

    Discusses the educational applications of experimental psychologist Mihaly Csikszentmihalyi's theory of peak experience, or optimal flow. Optimal flow refers to the receptive state people achieve when they are engaged in interesting and challenging activity. Includes an insightful critique of multimedia instruction from this perspective. (MJP)

  16. Growth parameter optimization and interface treatment for enhanced electron mobility in heavily strained GaInAs/AlInAs high electron mobility transistor structures

    SciTech Connect

    Fedoryshyn, Yuriy; Ostinelli, Olivier; Alt, Andreas; Pallin, Angel; Bolognesi, Colombo R., E-mail: colombo@ieee.org [Millimeter-Wave-Electronics Group, ETH Zurich, 8092 Zurich (Switzerland)

    2014-01-28

    The optimization of heavily strained Ga{sub 0.25}In{sub 0.75}As/Al{sub 0.48}In{sub 0.52}As high electron mobility transistor structures is discussed in detail. The growth parameters and the channel layer interfaces were optimized in order to maximize the mobility of the two-dimensional electron gas. Structures composed of an 11?nm thick channel layer and a 4?nm thick spacer layer exhibited electron mobilities as high as 15?100 cm{sup 2}/Vs and 70?000 cm{sup 2}/Vs at 300 and 77?K, respectively, for channels including InAs strained layers. The sheet carrier density was kept above 2.5?×?10{sup 12}?cm{sup ?2} throughout the entire study.

  17. Statistical optimization of growth medium for the production of the entomopathogenic and phytotoxic cyclic depsipeptide beauvericin from Fusarium oxysporum KFCC 11363P.

    PubMed

    Lee, Hee-Seok; Song, Hyuk-Hwan; An, Joong-Hoon; Shin, Cha-Gyun; Lee, Gung Pyo; Lee, Chan

    2008-01-01

    The production of the entomopathogenic and phytotoxic cyclic depsipeptide beauvericin (BEA) was studied in submerged cultures of Fusarium oxysporum KFCC 11363P isolated in Korea. The influences of various factors on mycelia growth and BEA production were examined in both complete and chemically defined culture media. The mycelia growth and BEA production were highest in Fusarium defined medium. The optimal carbon and nitrogen sources for maximizing BEA production were glucose and NaNO3, respectively. The carbon/ nitrogen ratio for maximal production of BEA was investigated using response surface methodology (RSM). Equations derived by differentiation of the RSM model revealed that the production of BEA was maximal when using 108 mM glucose and 25 mM NaNO3. PMID:18239431

  18. 64 ?W pulsed terahertz emission from growth optimized InGaAs/InAlAs heterostructures with separated photoconductive and trapping regions

    NASA Astrophysics Data System (ADS)

    Dietz, Roman J. B.; Globisch, Björn; Gerhard, Marina; Velauthapillai, Ajanthkrishna; Stanze, Dennis; Roehle, Helmut; Koch, Martin; Göbel, Thorsten; Schell, Martin

    2013-08-01

    We present results on optimized growth temperatures and layer structure design of high mobility photoconductive Terahertz (THz) emitters based on molecular beam epitaxy grown In0.53Ga0.47As/In0.52Al0.48As multilayer heterostructures (MLHS). The photoconductive antennas made of these MLHS are evaluated as THz emitters in a THz time domain spectrometer and with a Golay cell. We measured a THz bandwidth in excess of 4 THz and average THz powers of up to 64 ?W corresponding to an optical power-to-THz power conversion efficiency of up to 2 × 10-3.

  19. Seed Layer Dependence of ZnO Nanorod Growth

    Microsoft Academic Search

    Daryl Spencer; Amy Hor; Huan Liang; Parameswar Hari

    2010-01-01

    ZnO is a wide band gap semiconductor for optoelectronic applications such as solar cells, transparent conducting electrodes, and chemicals sensors. In past decades, significant progress has been achieved in controlled growth of ZnO nanorods and nanotubes. In this study we investigate the optimization of the growth properties such as orientation, diameter and shape of ZnO nanorods grown by a low

  20. Bridgman crystal growth

    NASA Technical Reports Server (NTRS)

    Carlson, Frederick

    1990-01-01

    The objective of this theoretical research effort was to improve the understanding of the growth of Pb(x)Sn(1-x)Te and especially how crystal quality could be improved utilizing the microgravity environment of space. All theoretical growths are done using the vertical Bridgman method. It is believed that improved single crystal yields can be achieved by systematically identifying and studying system parameters both theoretically and experimentally. A computational model was developed to study and eventually optimize the growth process. The model is primarily concerned with the prediction of the thermal field, although mass transfer in the melt and the state of stress in the crystal were of considerable interest. The evolution is presented of the computer simulation and some of the important results obtained. Diffusion controlled growth was first studied since it represented a relatively simple, but nontheless realistic situation. In fact, results from this analysis prompted a study of the triple junction region where the melt, crystal, and ampoule wall meet. Since microgravity applications were sought because of the low level of fluid movement, the effect of gravitational field strength on the thermal and concentration field was also of interest. A study of the strength of coriolis acceleration on the growth process during space flight was deemed necessary since it would surely produce asymmetries in the flow field if strong enough. Finally, thermosolutal convection in a steady microgravity field for thermally stable conditions and both stable and unstable solutal conditions was simulated.

  1. Developing Optimal Growth Parameters for the Green Microalgae Nannochloris oculata and the Diatom Nitzschia sp. for Large scale Raceway Production 

    E-print Network

    Luedecke, Phillip Ryan

    2011-10-21

    detrimental effects. These factors can affect growth and evidence suggests an interaction that exacerbates these effects. In an outdoor culture there are few practical control variables other than pond depth. As cultivation depth increases, the algae undergo...

  2. Culture of Primary Rat Hippocampal Neurons: Design, Analysis, and Optimization of a Microfluidic Device for Cell Seeding, Coherent Growth, and Solute Delivery

    PubMed Central

    Barbati, A. C.; Fang, C.; Banker, G. A.; Kirby, B. J.

    2013-01-01

    We present the design, analysis, construction, and culture results of a microfluidic device for the segregation and chemical stimulation of primary rat hippocampal neurons. Our device is designed to achieve spatio temporal solute delivery to discrete sections of neurons with mitigated mechanical stress. We implement a geometric guidance technique to direct axonal processes of the neurons into specific areas of the device to achieve solute segregation along routed cells. Using physicochemical modeling, we predict flows, concentration profiles, and mechanical stresses within pertiment sections of the device. We demonstrate cell viability and growth within the closed device over a period of 11 days. Additionally, our modeling methodology may be generalized and applied to other device geometries. PMID:22965807

  3. Optimization of Growth of GaInNAs Dilute Nitrides for Multi-junction Solar Cell Applications

    Microsoft Academic Search

    Yukiko Shimizu; Naoya Miyashita; Yusuke Mura; Akira Uedono; Yoshitaka Okada

    2006-01-01

    We have investigated the effect of growth temperature on the final crystal quality of GaInNAs solar cells in atomic hydrogen-assisted molecular beam epitaxy (H-MBE). A higher growth temperature of ~500degC has been found to be the optimum and resulted in both improved crystal quality and solar cell performance. The photoluminescence (PL) peak intensity was one order of magnitude stronger and

  4. Optimal synthesis for the minimum time control problems of fed-batch bioprocesses for growth functions with two maxima

    E-print Network

    Paris-Sud XI, Université de

    volume (representing a completely full tank). The optimal synthesis for this problem has been obtained with a highly concentrated solution without any removal of liquid before the end of the culture. This operating-Bang type: it consists of filling the reactor up to the maximum volume with the maximum input flow rate

  5. Optimal synthesis for the minimum time control problems of fed-batch bioprocesses for growth functions with two maxima

    E-print Network

    Paris-Sud XI, Université de

    volume (representing a completely full tank). The optimal synthesis for this problem has been obtained of feeding the reactor with a highly concentrated solution without any removal of liquid before the end-Bang type: it consists of filling the reactor up to the maximum volume with the maximum input flow rate

  6. Extracellular Calcium and Magnesium, but Not Iron, Are Needed for Optimal Growth of Blastomyces dermatitidis Yeast Form Cells In Vitro

    Microsoft Academic Search

    Steven S. Giles; Charles J. Czuprynski

    2004-01-01

    Iron is an essential nutrient for virtually all microorganisms. Although the human body contains an abundance of iron, the majority is bound to hemoglobin, myoglobin, and cytochromes and thus is not available in a form that can be used to support the growth of microorganisms (16). The availability of ferric iron is further limited by transferrin, a high-affinity iron-bind- ing

  7. Omic data from evolved E. coli are consistent with computed optimal growth from genome-scale models

    Microsoft Academic Search

    Nathan E. Lewis; Kim K. Hixson; Tom M. Conrad; Joshua A. Lerman; Pep Charusanti; Ashoka D. Polpitiya; Joshua N. Adkins; Gunnar Schramm; Samuel O. Purvine; Daniel Lopez-Ferrer; Karl K. Weitz; Roland Eils; Rainer König; Richard D. Smith; Bernhard O. Palsson

    2010-01-01

    After hundreds of generations of adaptive evolution at exponential growth, Escherichia coli grows as predicted using flux balance analysis (FBA) on genome-scale metabolic models (GEMs). However, it is not known whether the predicted pathway usage in FBA solutions is consistent with gene and protein expression in the wild-type and evolved strains. Here, we report that >98% of active reactions from

  8. Optimal Growth and Ethanol Production from Xylose by Recombinant Saccharomyces cerevisiae Require Moderate d-Xylulokinase Activity

    PubMed Central

    Jin, Yong-Su; Ni, Haiying; Laplaza, Jose M.; Jeffries, Thomas W.

    2003-01-01

    d-Xylulokinase (XK) is essential for the metabolism of d-xylose in yeasts. However, overexpression of genes for XK, such as the Pichia stipitis XYL3 gene and the Saccharomyces cerevisiae XKS gene, can inhibit growth of S. cerevisiae on xylose. We varied the copy number and promoter strength of XYL3 or XKS1 to see how XK activity can affect xylose metabolism in S. cerevisiae. The S. cerevisiae genetic background included single integrated copies of P. stipitis XYL1 and XYL2 driven by the S. cerevisiae TDH1 promoter. Multicopy and single-copy constructs with either XYL3 or XKS1, likewise under control of the TDH1 promoter, or with the native P. stipitis promoter were introduced into the recombinant S. cerevisiae. In vitro enzymatic activity of XK increased with copy number and promoter strength. Overexpression of XYL3 and XKS1 inhibited growth on xylose but did not affect growth on glucose even though XK activities were three times higher in glucose-grown cells. Growth inhibition increased and ethanol yields from xylose decreased with increasing XK activity. Uncontrolled XK expression in recombinant S. cerevisiae is inhibitory in a manner analogous to the substrate-accelerated cell death observed with an S. cerevisiae tps1 mutant during glucose metabolism. To bypass this effect, we transformed cells with a tunable expression vector containing XYL3 under the control of its native promoter into the FPL-YS1020 strain and screened the transformants for growth on, and ethanol production from, xylose. The selected transformant had approximately four copies of XYL3 per haploid genome and had moderate XK activity. It converted xylose into ethanol efficiently. PMID:12514033

  9. Optimality Conditions for Cell-Fate Heterogeneity That Maximize the Effects of Growth Factors in PC12 Cells

    PubMed Central

    Mouri, Kazunari; Sako, Yasushi

    2013-01-01

    Recently, the heterogeneity that arises from stochastic fate decisions has been reported for several types of cancer-derived cell lines and several types of clonal cells grown under constant environmental conditions. However, the relation between this stochasticity and the responsiveness to extracellular stimuli remains largely unknown. Here we focused on the fate decisions of the PC12 cell line, which was derived from rat pheochromocytoma, and is a model system to study differentiation into sympathetic neurons. Whereas epidermal growth factor (EGF) stimulates the proliferation of populations of PC12 cells, nerve growth factor (NGF) promotes the differentiation of neurites to neuron-like cells. We found that phenotypic heterogeneity increased with time at several surrounding serum concentrations, suggesting stochastic cell-fate decisions in single cells. We made a simple mathematical model assuming Markovian transitions of the cell fates, and estimated the transition rates based on Bayes' theorem. The model suggests that depending on the serum concentration, EGF (NGF) even directs differentiation (proliferation) at the single-cell level. The maximum effects of the growth factors were ensured when the transition rates were appropriately controlled by the serum concentration to produce a nonextremal, moderate amount of cell-fate heterogeneity. Our model was validated by the experimental finding that the means and variances of the local cell densities obey a power-law relationship. These results suggest that even when efficient responses to growth factors are observed at the population level, the growth factors stochastically direct the cell-fate decisions in different directions at the single-cell level. PMID:24244131

  10. Comparing Science Achievement Constructs: Targeted and Achieved

    ERIC Educational Resources Information Center

    Ferrara, Steve; Duncan, Teresa

    2011-01-01

    This article illustrates how test specifications based solely on academic content standards, without attention to other cognitive skills and item response demands, can fall short of their targeted constructs. First, the authors inductively describe the science achievement construct represented by a statewide sixth-grade science proficiency test.…

  11. A nuclear localization of the infectious haematopoietic necrosis virus NV protein is necessary for optimal viral growth

    USGS Publications Warehouse

    Choi, M.K.; Moon, C.H.; Ko, M.S.; Lee, U.-H.; Cho, W.J.; Cha, S.J.; Do, J.W.; Heo, G.J.; Jeong, S.G.; Hahm, Y.S.; Harmache, A.; Bremont, M.; Kurath, G.; Park, J.-W.

    2011-01-01

    The nonvirion (NV) protein of infectious hematopoietic necrosis virus (IHNV) has been previously reported to be essential for efficient growth and pathogenicity of IHNV. However, little is known about the mechanism by which the NV supports the viral growth. In this study, cellular localization of NV and its role in IHNV growth in host cells was investigated. Through transient transfection in RTG-2 cells of NV fused to green fluorescent protein (GFP), a nuclear localization of NV was demonstrated. Deletion analyses showed that the 32EGDL35 residues were essential for nuclear localization of NV protein, and fusion of these 4 amino acids to GFP directed its transport to the nucleus. We generated a recombinant IHNV, rIHNV-NV-?EGDL in which the 32EGDL35 was deleted from the NV. rIHNVs with wild-type NV (rIHNV-NV) or with the NV gene replaced with GFP (rIHNV-?NV-GFP) were used as controls. RTG-2 cells infected with rIHNV-?NV-GFP and rIHNV-NV-?EGDL yielded 12- and 5-fold less infectious virion, respectively, than wild type rIHNV-infected cells at 48 h post-infection (p.i.). While treatment with poly I:C at 24 h p.i. did not inhibit replication of wild-type rIHNVs, replication rates of rIHNV-?NV-GFP and rIHNV-NV-?EGDL were inhibited by poly I:C. In addition, both rIHNV-?NV and rIHNV-NV-?EGDL induced higher levels of expressions of both IFN1 and Mx1 than wild-type rIHNV. These data suggest that the IHNV NV may support the growth of IHNV through inhibition of the INF system and the amino acid residues of 32EGDL35 responsible for nuclear localization are important for the inhibitory activity of NV.

  12. Generation of a high-fidelity antibody against nerve growth factor using library scanning mutagenesis and validation with structures of the initial and optimized Fab-antigen complexes.

    PubMed

    La Porte, Sherry L; Eigenbrot, Charles; Ultsch, Mark; Ho, Wei-Hsien; Foletti, Davide; Forgie, Alison; Lindquist, Kevin C; Shelton, David L; Pons, Jaume

    2014-01-01

    Nerve growth factor (NGF) is indispensable during normal embryonic development and critical for the amplification of pain signals in adults. Intervention in NGF signaling holds promise for the alleviation of pain resulting from human diseases such as osteoarthritis, cancer and chronic lower back disorders. We developed a fast, high-fidelity method to convert a hybridoma-derived NGF-targeted mouse antibody into a clinical candidate. This method, termed Library Scanning Mutagenesis (LSM), resulted in the ultra-high affinity antibody tanezumab, a first-in-class anti-hyperalgesic specific for an NGF epitope. Functional and structural comparisons between tanezumab and the mouse 911 precursor antibody using neurotrophin-specific cell survival assays and X-ray crystal structures of both Fab-antigen complexes illustrated high fidelity retention of the NGF epitope. These results suggest the potential for wide applicability of the LSM method for optimization of well-characterized antibodies during humanization. PMID:24830649

  13. Generation of a high-fidelity antibody against nerve growth factor using library scanning mutagenesis and validation with structures of the initial and optimized Fab-antigen complexes

    PubMed Central

    La Porte, Sherry L; Eigenbrot, Charles; Ultsch, Mark; Ho, Wei-Hsien; Foletti, Davide; Forgie, Alison; Lindquist, Kevin C; Shelton, David L; Pons, Jaume

    2014-01-01

    Nerve growth factor (NGF) is indispensable during normal embryonic development and critical for the amplification of pain signals in adults. Intervention in NGF signaling holds promise for the alleviation of pain resulting from human diseases such as osteoarthritis, cancer and chronic lower back disorders. We developed a fast, high-fidelity method to convert a hybridoma-derived NGF-targeted mouse antibody into a clinical candidate. This method, termed Library Scanning Mutagenesis (LSM), resulted in the ultra-high affinity antibody tanezumab, a first-in-class anti-hyperalgesic specific for an NGF epitope. Functional and structural comparisons between tanezumab and the mouse 911 precursor antibody using neurotrophin-specific cell survival assays and X-ray crystal structures of both Fab-antigen complexes illustrated high fidelity retention of the NGF epitope. These results suggest the potential for wide applicability of the LSM method for optimization of well-characterized antibodies during humanization. PMID:24830649

  14. Energy growth in the compliant channel

    E-print Network

    Hoepffner, Jérôme

    Energy growth in the compliant channel Jérôme Hoepffner Julien Favier, Alessandro Bottaro #12: 2) Optimality: #12;"=0, stable #12;Optimization results Growth enveloppe Energy evolution There are clearly two mechanisms, with different growth and different time scales #12;Optimization results Growth

  15. Plasma Enhanced Growth of Carbon Nanotubes For Ultrasensitive Biosensors

    NASA Technical Reports Server (NTRS)

    Cassell, Alan M.; Meyyappan, M.

    2004-01-01

    The multitude of considerations facing nanostructure growth and integration lends itself to combinatorial optimization approaches. Rapid optimization becomes even more important with wafer-scale growth and integration processes. Here we discuss methodology for developing plasma enhanced CVD growth techniques for achieving individual, vertically aligned carbon nanostructures that show excellent properties as ultrasensitive electrodes for nucleic acid detection. We utilize high throughput strategies for optimizing the upstream and downstream processing and integration of carbon nanotube electrodes as functional elements in various device types. An overview of ultrasensitive carbon nanotube based sensor arrays for electrochemical bio-sensing applications and the high throughput methodology utilized to combine novel electrode technology with conventional MEMS processing will be presented.

  16. Plasma Enhanced Growth of Carbon Nanotubes For Ultrasensitive Biosensors

    NASA Technical Reports Server (NTRS)

    Cassell, Alan M.; Li, J.; Ye, Q.; Koehne, J.; Chen, H.; Meyyappan, M.

    2004-01-01

    The multitude of considerations facing nanostructure growth and integration lends itself to combinatorial optimization approaches. Rapid optimization becomes even more important with wafer-scale growth and integration processes. Here we discuss methodology for developing plasma enhanced CVD growth techniques for achieving individual, vertically aligned carbon nanostructures that show excellent properties as ultrasensitive electrodes for nucleic acid detection. We utilize high throughput strategies for optimizing the upstream and downstream processing and integration of carbon nanotube electrodes as functional elements in various device types. An overview of ultrasensitive carbon nanotube based sensor arrays for electrochemical biosensing applications and the high throughput methodology utilized to combine novel electrode technology with conventional MEMS processing will be presented.

  17. Multiple long-term, experimentally-evolved populations of Escherichia coli acquire dependence upon citrate as an iron chelator for optimal growth on glucose

    PubMed Central

    2012-01-01

    Background Specialization for ecological niches is a balance of evolutionary adaptation and its accompanying tradeoffs. Here we focus on the Lenski Long-Term Evolution Experiment, which has maintained cultures of Escherichia coli in the same defined seasonal environment for 50,000 generations. Over this time, much adaptation and specialization to the environment has occurred. The presence of citrate in the growth media selected one lineage to gain the novel ability to utilize citrate as a carbon source after 31,000 generations. Here we test whether other strains have specialized to rely on citrate after 50,000 generations. Results We show that in addition to the citrate-catabolizing strain, three other lineages evolving in parallel have acquired a dependence on citrate for optimal growth on glucose. None of these strains were stimulated indirectly by the sodium present in disodium citrate, nor exhibited even partial utilization of citrate as a carbon source. Instead, all three of these citrate-stimulated populations appear to rely on it as a chelator of iron. Conclusions The strains we examine here have evolved specialization to their environment through apparent loss of function. Our results are most consistent with the accumulation of mutations in iron transport genes that were obviated by abundant citrate. The results present another example where a subtle decision in the design of an evolution experiment led to unexpected evolutionary outcomes. PMID:22909317

  18. Achieving Holevo Bound in Quantum Measurement

    E-print Network

    Nima Lashkari

    2005-11-19

    We show that information gain in a qubit measurement is optimal under a Von Neumann measurement. For an initially mixed apparatus kept in touch with a qubit, the conditions for achieving the equality sign of Holevo bound on the information accessible to apparatus are derived. These constraints can be identified as the conditions for the optimization of information gain in a qubit measurement. At the end, we will generalize the idea to qudit measurements using a phase-shift gate.

  19. Optimization of processing parameters on the controlled growth of ZnO nanorod arrays for the performance improvement of solid-state dye-sensitized solar cells

    SciTech Connect

    Lee, Yi-Mu, E-mail: ymlee@nuu.edu.t [Department of Electronic Engineering, National United University, MiaoLi 36003, Taiwan (China); Yang, Hsi-Wen [Department of Materials Science and Engineering, National United University, MiaoLi 36003, Taiwan (China)

    2011-03-15

    High-transparency and high quality ZnO nanorod arrays were grown on the ITO substrates by a two-step chemical bath deposition (CBD) method. The effects of processing parameters including reaction temperature (25-95 {sup o}C) and solution concentration (0.01-0.1 M) on the crystal growth, alignment, optical and electrical properties were systematically investigated. It has been found that these process parameters are critical for the growth, orientation and aspect ratio of the nanorod arrays, showing different structural and optical properties. Experimental results reveal that the hexagonal ZnO nanorod arrays prepared under reaction temperature of 95 {sup o}C and solution concentration of 0.03 M possess highest aspect ratio of {approx}21, and show the well-aligned orientation and optimum optical properties. Moreover the ZnO nanorod arrays based heterojunction electrodes and the solid-state dye-sensitized solar cells (SS-DSSCs) were fabricated with an improved optoelectrical performance. -- Graphical abstract: The ZnO nanorod arrays demonstrate well-alignment, high aspect ratio (L/D{approx}21) and excellent optical transmittance by low-temperature chemical bath deposition (CBD). Display Omitted Research highlights: > Investigate the processing parameters of CBD on the growth of ZnO nanorod arrays. > Optimization of CBD process parameters: 0.03 M solution concentration and reaction temperature of 95 {sup o}C. > The prepared ZnO samples possess well-alignment and high aspect ratio (L/D{approx}21). > An n-ZnO/p-NiO heterojunction: great rectifying behavior and low leakage current. > SS-DSSC has J{sub SC} of 0.31 mA/cm{sup 2} and V{sub OC} of 590 mV, and an improved {eta} of 0.059%.

  20. Achieving Public Schools

    ERIC Educational Resources Information Center

    Abowitz, Kathleen Knight

    2011-01-01

    Public schools are functionally provided through structural arrangements such as government funding, but public schools are achieved in substance, in part, through local governance. In this essay, Kathleen Knight Abowitz explains the bifocal nature of achieving public schools; that is, that schools are both subject to the unitary Public compact of…

  1. Confronting the Achievement Gap

    ERIC Educational Resources Information Center

    Gardner, David

    2007-01-01

    This article talks about the large achievement gap between children of color and their white peers. The reasons for the achievement gap are varied. First, many urban minorities come from a background of poverty. One of the detrimental effects of growing up in poverty is receiving inadequate nourishment at a time when bodies and brains are rapidly…

  2. Achievement Test Program.

    ERIC Educational Resources Information Center

    Ohio State Dept. of Education, Columbus. Trade and Industrial Education Service.

    The Ohio Trade and Industrial Education Achievement Test battery is comprised of seven basic achievement tests: Machine Trades, Automotive Mechanics, Basic Electricity, Basic Electronics, Mechanical Drafting, Printing, and Sheet Metal. The tests were developed by subject matter committees and specialists in testing and research. The Ohio Trade and…

  3. Achieving Perspective Transformation.

    ERIC Educational Resources Information Center

    Nowak, Jens

    Perspective transformation is a consciously achieved state in which the individual's perspective on life is transformed. The new perspective serves as a vantage point for life's actions and interactions, affecting the way life is lived. Three conditions are basic to achieving perspective transformation: (1) "feeling" experience, i.e., getting in…

  4. Sex Differences in Mathematics Achievement--A Longitudinal Study.

    ERIC Educational Resources Information Center

    Hilton, Thomas L.; Berglund, Gosta W.

    With the objective of investigating sex-typed interests as possible causes of differences in mathematics achievement between the sexes, the study made use of longitudinal data from the Growth Study begun at E. T. S. in 1961. Growth in mathematics achievement as measured by STEP Math and SCAT-Q was compared with changing interest patterns as…

  5. Achieving IP routing stability with optical bypass

    Microsoft Academic Search

    Mohit Chamania; Marcel Caria; Admela Jukan

    2010-01-01

    The phenomenal growth of the Internet coupled with the emergence of new QoS-aware services in the network has put an enormous strain on current networks. Research efforts towards optimizing the performance of IP networks have been focused on increasing the utilization of the network while minimizing additional resources used. Many such paradigms developed under the umbrella of Traffic and Network

  6. Service Quality To achieve our mission,

    E-print Network

    Weinberger, Hans

    , at which processes must we excel? Staff Development Learning & Growth: To excel at our critical processesFocusedCultureofAccountabilityCost-Effective3C's C-2: Stewardship Excellence (optimize facilities lifecycle costs, preserve & enhance facilities quality) F-2: Strengthen IT systems quality I-1: Improve proactive efforts, responsiveness

  7. Achievement goals and emotions.

    PubMed

    Puente-Díaz, Rogelio

    2013-01-01

    The present investigation examined the influence of three antecedents (fear of failure, personal standards, and concern over mistakes) on achievement goals and also the influence of achievement goals on two affective outcomes (enjoyment and hope). Participants were 204 tennis players from Mexico. Structural Equation Modeling (SEM) was used to analyze the results. We found support for the role of fear of failure, personal standards, and concern over mistakes as antecedents of some achievement goals. Whereas mastery-approach had a significant influence on enjoyment and hope, performance-approach goals had a significant influence on hope only. The implications of the results are discussed. PMID:23705292

  8. Carbon nanofiber growth optimization for their use as electrocatalyst support in proton exchange membrane (PEM) fuel cells.

    PubMed

    Lázaro, M J; Sebastián, D; Suelves, I; Moliner, R

    2009-07-01

    Carbon nanofiber (CNF) growth by catalytic decomposition of methane in a fixed-bed reactor was studied out to elucidate the influence of some important reaction conditions: temperature, space velocity and reactant partial pressure, in the morphological properties of the carbonaceous material obtained. The main objective is to synthesize a suitable carbonaceous nanomaterial to be used as support in platinum based electrocatalysts for Proton Exchange Membrane Fuel Cells (PEMFC) which improves current carbon blacks. High specific surface area is required in an electrocatalyst support since platinum dispersion is enhanced and so a cost-effective usage and high catalytic activity. Good electrical conductivity of carbon support is also required since the fuel cell power density is improved. With this proposal, characterization was carried out by nitrogen physisorption, XRD, SEM and TPO. The results were analysed by a factorial design and analysis of variance (ANOVA) in order to find an empirical correlation between operating conditions and CNF characteristics. It was found that the highest specific surface area and pore volume were found at 823 K and at a space velocity of 10 L gcat(-1) h(-1). The graphitic character of CNF, which is known to influence the electrical conductivity, presented a maximum value at temperatures between 923 K and 973 K. SEM images showed a narrow size distribution of CNF diameter between 40 and 90 nm and homogeneous appearance. PMID:19916456

  9. Achieving Robust Design from Computer Simulations

    Microsoft Academic Search

    Ron A. Bates; Ron S. Kenett; David M. Steinberg; Henry P. Wynn

    Computer simulations are widely used during product development. In particular, computer experiments are often conducted in order to optimize both product and process performance while respecting constraints that may be imposed. Several methods for achieving robust design in this context are described and compared with the aid of a simple example problem. The methods presented compare classical as well as

  10. Time Perspective and Causal Attributions for Achievement

    ERIC Educational Resources Information Center

    Wolf, Fredric M.; Savickas, Mark L.

    1985-01-01

    This study examines the relationship between adolescents' time perspective and attributions for achievement. Measures of time perspective (continuity, optimism, pessimism, and utilization) and attributions (ability, effort, context, and luck) independently assessed for success and failure were administered to 10th graders. Implications for…

  11. research endeavours achieving their

    E-print Network

    University of Technology has a proven track record of collaborating with industry to address these challengesresearch endeavours achieving their greatest potential #12;#12;1 Welcome to IP Commercialisation

  12. Optimization of struvite fertilizer formation from baker's yeast wastewater: growth and nutrition of maize and tomato plants.

    PubMed

    Uysal, Ayla; Demir, Sinan; Sayilgan, Emine; Eraslan, Figen; Kucukyumuk, Zeliha

    2014-03-01

    Struvite precipitate obtained from yeast industry anaerobic effluent with high ammonium nitrogen (NH4-N) was investigated for fertilizer effect on plant growth and nutrition according to applications of N, nitrogen/phosphorus/potassium (NPK), and control. Optimum struvite formation conditions were determined via Box-Behnken design. Optimum condition was obtained at pH 9.0 and Mg/N/P molar ratio of 1.5:1:1. Under these conditions, heavy metal concentrations in the obtained struvite precipitate (except Cu) were below the detection limits. In addition to high N, P, and Mg content, energy-dispersive X-ray (EDX) analysis showed that the struvite also included the nutritional elements Ca, K, Na, and Fe. X-ray diffraction (XRD) analysis revealed the complex structures of NaAl(SO4)2(H2O)12, NaMn(2+)Fe2(PO4)3, and (Na2,Ca)O2(Fe,Mn)O.P2O5 in the precipitate. High Na(+) and Ca(2+) concentrations in the anaerobic effluent reacted with phosphate during struvite precipitation. Different applications and struvite dosages significantly affected fresh and dry weights and nutrient element uptakes by plants (P?

  13. The Reduced Genome of the Francisella tularensis Live Vaccine Strain (LVS) Encodes Two Iron Acquisition Systems Essential for Optimal Growth and Virulence

    PubMed Central

    Pérez, Natalie Marie; Ramakrishnan, Girija

    2014-01-01

    Bacterial pathogens require multiple iron-specific acquisition systems for survival within the iron-limiting environment of the host. Francisella tularensis is a virulent intracellular pathogen that can replicate in multiple cell-types. To study the interrelationship of iron acquisition capability and virulence potential of this organism, we generated single and double deletion mutants within the ferrous iron (feo) and ferric-siderophore (fsl) uptake systems of the live vaccine strain (LVS). The Feo system was disrupted by a partial deletion of the feoB gene (?feoB?), which led to a growth defect on iron-limited modified Muller Hinton agar plates. 55Fe uptake assays verified that the ?feoB? mutant had lost the capacity for ferrous iron uptake but was still competent for 55Fe-siderophore-mediated ferric iron acquisition. Neither the ?feoB? nor the siderophore-deficient ?fslA mutant was defective for replication within J774A.1 murine macrophage-like cells, thus demonstrating the ability of LVS to survive using either ferrous or ferric sources of intracellular iron. A LVS ?fslA ?feoB? mutant defective for both ferrous iron uptake and siderophore production was isolated in the presence of exogenous F. tularensis siderophore. In contrast to the single deletion mutants, the ?fslA ?feoB? mutant was unable to replicate within J774A.1 cells and was attenuated in virulence following intraperitoneal infection of C57BL/6 mice. These studies demonstrate that the siderophore and feoB-mediated ferrous uptake systems are the only significant iron acquisition systems in LVS and that they operate independently. While one system can compensate for loss of the other, both are required for optimal growth and virulence. PMID:24695402

  14. Optimization of cultural conditions of Arthrobacter sp. Sphe3 for growth-associated chromate(VI) reduction in free and immobilized cell systems.

    PubMed

    Ziagova, M G; Koukkou, A I; Liakopoulou-Kyriakides, M

    2014-01-01

    The current study aimed to characterize Arthrobacter sp. Sphe3 ability to reduce Cr(VI) in suspended cell cultures as well as in immobilized form using Ca-alginate beads. Adaptation studies in the presence of 5 mg L(-1) Cr(VI) showed a significant increase in specific growth rate from 0.25 to 0.3 h(-1) and bioremoval percentage from 64% to 94% (p<0.05), whereas Arthrobacter sp. Sphe3 could tolerate up to 50 mg L(-1) Cr(VI). Optimization of culture conditions resulted in complete reduction of 45 mg L(-1) Cr(VI) at 30 °C, pH 8 and 10 g L(-1) of glucose. High glucose concentrations helped at reducing (80±2.4)% of initial 100 mg L(-1) Cr(VI), whereas the bacterial strain could tolerate 850 mg L(-1) Cr(VI). Cr(III) formation was first evidenced by the appearance of a green insoluble precipitate in the medium. Cell biomass was successfully immobilized in Ca-alginate beads that were evaluated for their stability. Cell release was sharply decreased when 4% Na-alginate was used under non-shaking conditions. Biotransformation efficiency was enhanced when 25-50 mg cells mL(-1) Na-alginate from the exponential growth phase were collected and co-encapsulated with either 1% glucose and 0.5% (NH4)2SO4, or 1% LB medium. Immobilized biocatalyst could be reused up to 6 continuous cycles in the presence of 10 mg L(-1) Cr(VI), but its performance was lowered at higher metal concentrations comparing with free cells that significantly maintained their reducing ability up to 300 mg L(-1) Cr(VI). PMID:24183628

  15. Epitaxial growth and surface metallic nature of LaNiO3 thin films

    Microsoft Academic Search

    K. Tsubouchi; I. Ohkubo; H. Kumigashira; Y. Matsumoto; T. Ohnishi; M. Lippmaa; H. Koinuma; M. Oshima

    2008-01-01

    In situ epitaxial growth control of LaNiO3 (LNO) films at high oxygen pressure has been successfully achieved using a combination of pulsed laser deposition and high-pressure reflection high-energy electron diffraction (RHEED). RHEED oscillations, indicative of epitaxial layer-by-layer growth, were clearly observed during LNO deposition under optimal conditions. The film surfaces were composed of atomically flat terraces and steps. Detailed photoelectron

  16. The effects of alternate optimal solutions in constraint-based genome-scale metabolic models

    Microsoft Academic Search

    R. Mahadevan; C. H. Schilling

    2003-01-01

    Genome-scale constraint-based models of several organisms have now been constructed and are being used for model driven research. A key issue that may arise in the use of such models is the existence of alternate optimal solutions wherein the same maximal objective (e.g., growth rate) can be achieved through different flux distributions. Herein, we investigate the effects that alternate optimal

  17. Synthesis, growth, optimization, bulk SR method growth, fabrication of indigenous optical element and anisotropic studies on guanidinium L-monohydrogen tartrate (GuHT) single crystal for nonlinear optical device applications

    NASA Astrophysics Data System (ADS)

    Vivek, P.; Roop Kumar, R.; Murugakoothan, P.

    2015-02-01

    An organic NLO material guanidinium L-monohydrogen tartrate (GuHT) was grown by the slow evaporation technique using water as a solvent. The solubility and meta stable zone width was determined. The GuHT crystal belongs to orthorhombic system with noncentrosymmetric space group P212121. The morphology of the GuHT crystal was studied. The most prominent plane (0 0 1) was encouraged to grow in unidirection by Sankaranarayanan-Ramasamy (SR) method using water as a solvent. The growth conditions were optimized. The transparent GuHT single crystal of maximum width 15 mm and length 101 mm was obtained by employing SR method. The grown crystal was subjected to high resolution X-ray diffraction, UV-vis-NIR transmittance, refractive index, hardness, laser damage threshold and birefringence studies in different planes. The particle size dependent second harmonic generation efficiency for guanidinium L-monohydrogen tartrate was evaluated by Kurtz-Perry powder method using Nd:YAG laser, which established the existence of phase matching. The second harmonic generation (SHG) of GuHT crystal was investigated by the SHG Maker fringes technique.

  18. Optimization of Fed-Batch Saccharomyces cereWisiae Fermentation Using Dynamic Flux Balance Models

    E-print Network

    Mountziaris, T. J.

    ARTICLES Optimization of Fed-Batch Saccharomyces cereWisiae Fermentation Using Dynamic Flux Balance-batch Saccharomyces cereVisiae fermentation that couples a detailed steady-state description of primary carbon is that nutrient levels can be varied to achieve favorable growth conditions. Fed-batch yeast fermentation

  19. Molecular layer-by-layer growth of SrTiO 3 and BaTiO 3 films by laser molecular beam epitaxy

    Microsoft Academic Search

    T. Maeda; G. H. Lee; T. Ohnishi; M. Kawasaki; M. Yoshimoto; H. Koinuma

    1996-01-01

    Layer-by-layer growth of SrTiO3 and BaTiO3 films was achieved by laser molecular beam epitaxy (laser MBE) using SrTiO3 (100) substrate with alomieally Hat terraces and 0.4 nm steps. Fine streak pattern and intensity oscillation were persistently observed by reflection high-energy electron diffraction (RHHED) during the film growth under optimized conditions. When the growth was halted at any levels of RHEED

  20. Schools, School Quality and Academic Achievement: Evidence from the Philippines

    Microsoft Academic Search

    Marigee Bacolod; Justin Tobias

    2005-01-01

    A broad literature seeks to assess the importance of schools, proxies for school quality, and family background on children's achievement growth using the education production function. Using rich data from the Philippines, we introduce and estimate a model that imposes little structure on the relationship between intake achievement and follow-up achievement and evaluate school performance based on this estimated relationship.

  1. Indivisible. Good Schools=Health Economy. Poor Academic Achievement=Increased Unemployment. A Longitudinal Pilot Study on the Relationship between Job Growth and School Performance in 15 of Illinois' Largest Counties. A Report to Cook County Assessor Thomas Hynes.

    ERIC Educational Resources Information Center

    Kyle, Charles L.; Sufritz, Erica

    This longitudinal study indicates that educational reform and economic performance are indivisible. The first part of the study examines job growth or decline by type of job between 1972 and 1985 by county and ranks the counties based on their performance during the 13-year period. The second part of the study examines the relationship between the…

  2. Advanced Czochralski ingot growth

    SciTech Connect

    Lane, R.L.

    1982-04-01

    A summary of advanced Cz ingot-growth activities is presented. Five ingots (totalling 150 kg) were grown from one crucible by use of chunk silicon replenishment between ingot pulls. The cost of the ingot growth was reduced from $80/kg (conventional Cz growth) to $20/kg. Further improvements can be made by achieving a better understanding of crystalline silicon growth and the influence on growth of contaminants from the atmosphere and/or the crucible. This should lead to a higher percentage of monocrystalline growth and possible increased growth rates.

  3. Achievements of KEKB

    NASA Astrophysics Data System (ADS)

    Abe, Tetsuo; Akai, Kazunori; Akasaka, Norimasa; Akemoto, Mitsuo; Akiyama, Atsuyoshi; Arinaga, Mitsuhiro; Cai, Yunhai; Ebihara, Kiyokazu; Egawa, Kazumi; Enomoto, Atsushi; Ezura, Eiji; Flanagan, John; Fukuda, Shigeki; Fukuma, Hitoshi; Funakoshi, Yoshihiro; Furukawa, Kazuro; Furuya, Takaaki; Haba, Junji; Hara, Kazufumi; Higo, Toshiyasu; Hiramatsu, Shigenori; Hisamatsu, Hiromi; Honma, Hiroyuki; Honma, Teruya; Hosoyama, Kenji; Ieiri, Takao; Iida, Naoko; Ikeda, Hitomi; Ikeda, Mitsuo; Inagaki, Shigemi; Isagawa, Shigeru; Ishii, Hitoshi; Kabe, Atsushi; Kadokura, Eiichi; Kageyama, Tatsuya; Kakihara, Kazuhisa; Kako, Eiji; Kamada, Susumu; Kamitani, Takuya; Kanazawa, Ken-ichi; Katagiri, Hiroaki; Kato, Shigeki; Kawamoto, Takashi; Kazakov, Sergey; Kikuchi, Mitsuo; Kikutani, Eiji; Kitagawa, Kiyoshi; Koiso, Haruyo; Kojima, Yuuji; Komada, Ichitaka; Kubo, Tadashi; Kudo, Kikuo; Kurokawa, Shin-ichi; Marutsuka, Katsumi; Masuzawa, Mika; Matsumoto, Shuji; Matsumoto, Toshihiro; Michizono, Shinichiro; Mikawa, Katsuhiko; Mimashi, Toshihiro; Mitsuhashi, Toshiyuki; Mitsunobu, Shinji; Miura, Takako; Mori, Kenji; Morita, Akio; Morita, Yoshiyuki; Nakai, Hirotaka; Nakajima, Hiromitsu; Nakamura, Tatsuro T.; Nakanishi, Hiroshi; Nakanishi, Kota; Nakao, Katumi; Nakayama, Hisayoshi; Nishiwaki, Michiru; Ogawa, Yujiro; Ohmi, Kazuhito; Ohnishi, Yukiyoshi; Ohsawa, Satoshi; Ohsawa, Yasunobu; Ohuchi, Norihito; Oide, Katsunobu; Oki, Toshiyuki; Ono, Masaaki; Ozaki, Toshiyuki; Perevedentsev, Eugene; Sakai, Hiroshi; Sakamoto, Yutaka; Sato, Masayuki; Satoh, Kotaro; Satoh, Masanori; Seimiya, Yuji; Shibata, Kyo; Shidara, Tetsuo; Shimada, Miho; Stanic, Samo; Shirai, Mitsuru; Shirakawa, Akihiro; Sueno, Tsuyoshi; Suetake, Masaaki; Suetsugu, Yusuke; Sugahara, Ryuhei; Sugimura, Takashi; Suwada, Tsuyoshi; Tajima, Osamu; Takano, Susumu; Takasaki, Seiji; Takenaka, Tateru; Takeuchi, Yasunao; Takeuchi, Yasunori; Tawada, Masafumi; Tejima, Masaki; Tobiyama, Makoto; Tokuda, Noboru; Tsuchiya, Kiyosumi; Uehara, Sadaharu; Uno, Shoji; Wu, Yingzhi; Yamamoto, Noboru; Yamamoto, Yasuchika; Yano, Yoshiharu; Yokoyama, Kazue; Yoshida, Masato; Yoshida, Mitsuhiro; Yoshimoto, Shin-ichi; Yoshino, Kazuo; Yoshioka, Masakazu; Zhou, Demin; Zimmermann, Frank; Zong, Zhanguo

    2013-03-01

    The machine commissioning of KEKB started in December 1998 and its operation was terminated at the end of June 2010 to upgrade KEKB to SuperKEKB. In this paper, we summarize the history of KEKB and show the achievements made there.

  4. Aptitude, Intelligence, and Achievement.

    ERIC Educational Resources Information Center

    Wesman, Alexander G.

    1956-01-01

    Ways in which to determine whether the aptitude, intelligence, or achievement test is more helpful are discussed. A test's function, i.e., how the test results are used, appears to be the most logical method of discriminating between the types of tests. In educational testing, if the purpose is to evaluate the effectiveness of teaching or…

  5. Essays on Educational Achievement

    ERIC Educational Resources Information Center

    Ampaabeng, Samuel Kofi

    2013-01-01

    This dissertation examines the determinants of student outcomes--achievement, attainment, occupational choices and earnings--in three different contexts. The first two chapters focus on Ghana while the final chapter focuses on the US state of Massachusetts. In the first chapter, I exploit the incidence of famine and malnutrition that resulted to…

  6. Assessing Handwriting Achievement.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    Teachers in the school setting need to emphasize quality handwriting across the curriculum. Quality handwriting means that the written content is easy to read in either manuscript or cursive form. Handwriting achievement can be assessed, but not compared to the precision of assessing basic addition, subtraction, multiplication, and division facts.…

  7. Schools Achieving Gender Equity.

    ERIC Educational Resources Information Center

    Revis, Emma

    This guide is designed to assist teachers presenting the Schools Achieving Gender Equity (SAGE) curriculum for vocational education students, which was developed to align gender equity concepts with the Kentucky Education Reform Act (KERA). Included in the guide are lesson plans for classes on the following topics: legal issues of gender equity,…

  8. Achieving All Our Ambitions

    ERIC Educational Resources Information Center

    Hartley, Tricia

    2009-01-01

    National learning and skills policy aims both to build economic prosperity and to achieve social justice. Participation in higher education (HE) has the potential to contribute substantially to both aims. That is why the Campaign for Learning has supported the ambition to increase the proportion of the working-age population with a Level 4…

  9. Achieving Peace through Education.

    ERIC Educational Resources Information Center

    Clarken, Rodney H.

    While it is generally agreed that peace is desirable, there are barriers to achieving a peaceful world. These barriers are classified into three major areas: (1) an erroneous view of human nature; (2) injustice; and (3) fear of world unity. In a discussion of these barriers, it is noted that although the consciousness and conscience of the world…

  10. Aboriginal Student Achievement Program

    E-print Network

    Saskatchewan, University of

    Aboriginal Student Achievement Program (ASAP) For more information, contact: Program Information@arts.usask.ca artsandscience.usask.ca/students/aboriginal/asap.php "I really want to connect with other aboriginal students and hopefully inspire some of them to continue their studies." --Jacquelyne Nokusis, former ASAP student

  11. Issues in Appraising Achievement.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    Selected issues must be considered in choosing an effective assessment method from diverse procedures. External means of evaluation stress the use of national and state-developed tests to measure student achievement. In addition to external evaluations of students, administrators may use external tests for teachers. Internal means of evaluating…

  12. SALT and Spelling Achievement.

    ERIC Educational Resources Information Center

    Nelson, Joan

    A study investigated the effects of suggestopedic accelerative learning and teaching (SALT) on the spelling achievement, attitudes toward school, and memory skills of fourth-grade students. Subjects were 20 male and 28 female students from two self-contained classrooms at Kennedy Elementary School in Rexburg, Idaho. The control classroom and the…

  13. Advancing Student Achievement

    ERIC Educational Resources Information Center

    Walberg, Herbert J.

    2010-01-01

    For the last half century, higher spending and many modern reforms have failed to raise the achievement of students in the United States to the levels of other economically advanced countries. A possible explanation, says Herbert Walberg, is that much current education theory is ill informed about scientific psychology, often drawing on fads and…

  14. CEBAF accelerator achievements

    SciTech Connect

    Y.C. Chao, M. Drury, C. Hovater, A. Hutton, G.A. Krafft, M. Poelker, C. Reece, M. Tiefenback

    2011-06-01

    In the past decade, nuclear physics users of Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) have benefited from accelerator physics advances and machine improvements. As of early 2011, CEBAF operates routinely at 6 GeV, with a 12 GeV upgrade underway. This article reports highlights of CEBAF's scientific and technological evolution in the areas of cryomodule refurbishment, RF control, polarized source development, beam transport for parity experiments, magnets and hysteresis handling, beam breakup, and helium refrigerator operational optimization.

  15. Distributive Politics and Economic Growth

    Microsoft Academic Search

    Alberto Alesina

    1994-01-01

    We study the relationship between politics and economic growth in a simple model of endogenous growth with distributive conflict among agents endowed with varying capital\\/labor shares. We establish several results regarding the factor ownership of the median individual and the level of taxation, redistribution, and growth. Policies that maximize growth are optimal only for a government that cares solely about

  16. Achievement Goals and Achievement Emotions: A Meta-Analysis

    ERIC Educational Resources Information Center

    Huang, Chiungjung

    2011-01-01

    This meta-analysis synthesized 93 independent samples (N = 30,003) in 77 studies that reported in 78 articles examining correlations between achievement goals and achievement emotions. Achievement goals were meaningfully associated with different achievement emotions. The correlations of mastery and mastery approach goals with positive achievement

  17. In situ growth of NiCo2S4 nanotube arrays on Ni foam for supercapacitors: Maximizing utilization efficiency at high mass loading to achieve ultrahigh areal pseudocapacitance

    NASA Astrophysics Data System (ADS)

    Chen, Haichao; Jiang, Jianjun; Zhang, Li; Xia, Dandan; Zhao, Yuandong; Guo, Danqing; Qi, Tong; Wan, Houzhao

    2014-05-01

    Self-standing NiCo2S4 nanotube arrays have been in situ grown on Ni foam by the anion-exchange reaction and directly used as the electrode for supercapacitors. The NiCo2S4 nanotube in the arrays effectively reduces the inactive material and increases the electroactive surface area because of the ultrathin wall, which is quite competent to achieve high utilization efficiency at high electroactive materials mass loading. The NiCo2S4 nanotube arrays hybrid electrode exhibits an ultrahigh specific capacitance of 14.39 F cm-2 at 5 mA cm-2 with excellent rate performance (67.7% retention for current increases 30 times) and cycling stability (92% retention after 5000 cycles) at a high mass loading of 6 mg cm-2. High areal capacitance (4.68 F cm-2 at 10 mA cm-2), high energy density (31.5 Wh kg-1 at 156.6 W kg-1) and high power density (2348.5 W kg-1 at 16.6 Wh kg-1) can be achieved by assembling asymmetric supercapacitor with reduced graphene oxide at a total active material mass loading as high as 49.5 mg. This work demonstrates that NiCo2S4 nanotube arrays structure is a superior electroactive material for high-performance supercapacitors even at a mass loading of potential application-specific scale.

  18. Influence of Liquid Pulse Treatment with Growth Regulators on in vitro Propagation of Banana ( Musa spp. AAA)

    Microsoft Academic Search

    P. Madhulatha; M. Anbalagan; S. Jayachandran; N. Sakthivel

    2004-01-01

    The effect of liquid pulse treatment of growth regulators on in vitro propagation of banana (Musa spp. AAA) was studied. Optimal shoot proliferation rates were achieved due to the pulse treatment of 6-benzylaminopurine (BA) and kinetin combination (1:1) at the concentration of 50 mg l-1 for 60 min. Similarly high frequency of root induction was obtained due to pulse treatment

  19. FAMILY STRUCTURE TRANSITIONS AND CHILD ACHIEVEMENT

    Microsoft Academic Search

    Kimberly Anne Shaff; Nicholas H. Wolfinger; Lori Kowaleski-Jones; Ken R. Smith

    2008-01-01

    This article uses prospective data from the National Longitudinal Survey of Youth 1979 to investigate how children in divorced and never-married-mother families vary in reading and math achievement after parental remarriage. These are compared to children who remain in never-married, divorced, and continuously married families. Results based on growth curve modeling indicate that children remaining in single-parent families resulting from

  20. Growth rates of the population in a branching Brownian motion with an inhomogeneous breeding potential

    E-print Network

    Berestycki, Julien; Harris, John W; Harris, Simon C; Roberts, Matthew I

    2012-01-01

    We consider a branching particle system where each particle moves as an independent Brownian motion and breeds at a rate proportional to its distance from the origin raised to the power $p$, for $p\\in[0,2)$. The asymptotic behaviour of the right-most particle for this system is already known; in this article we give large deviations probabilities for particles following "difficult" paths, growth rates along "easy" paths, the total population growth rate, and we derive the optimal paths which particles must follow to achieve this growth rate.

  1. Achieving closure at Fernald

    SciTech Connect

    Bradburne, John; Patton, Tisha C.

    2001-02-25

    When Fluor Fernald took over the management of the Fernald Environmental Management Project in 1992, the estimated closure date of the site was more than 25 years into the future. Fluor Fernald, in conjunction with DOE-Fernald, introduced the Accelerated Cleanup Plan, which was designed to substantially shorten that schedule and save taxpayers more than $3 billion. The management of Fluor Fernald believes there are three fundamental concerns that must be addressed by any contractor hoping to achieve closure of a site within the DOE complex. They are relationship management, resource management and contract management. Relationship management refers to the interaction between the site and local residents, regulators, union leadership, the workforce at large, the media, and any other interested stakeholder groups. Resource management is of course related to the effective administration of the site knowledge base and the skills of the workforce, the attraction and retention of qualified a nd competent technical personnel, and the best recognition and use of appropriate new technologies. Perhaps most importantly, resource management must also include a plan for survival in a flat-funding environment. Lastly, creative and disciplined contract management will be essential to effecting the closure of any DOE site. Fluor Fernald, together with DOE-Fernald, is breaking new ground in the closure arena, and ''business as usual'' has become a thing of the past. How Fluor Fernald has managed its work at the site over the last eight years, and how it will manage the new site closure contract in the future, will be an integral part of achieving successful closure at Fernald.

  2. Fast interconnect optimization 

    E-print Network

    Li, Zhuo

    2006-04-12

    As the continuous trend of Very Large Scale Integration (VLSI) circuits technology scaling and frequency increases, delay optimization techniques for interconnect are increasingly important for achieving timing closure of ...

  3. Autoimmune control of lesion growth in CNS with minimal damage

    NASA Astrophysics Data System (ADS)

    Mathankumar, R.; Mohan, T. R. Krishna

    2013-07-01

    Lesions in central nervous system (CNS) and their growth leads to debilitating diseases like Multiple Sclerosis (MS), Alzheimer's etc. We developed a model earlier [1, 2] which shows how the lesion growth can be arrested through a beneficial auto-immune mechanism. We compared some of the dynamical patterns in the model with different facets of MS. The success of the approach depends on a set of control parameters and their phase space was shown to have a smooth manifold separating the uncontrolled lesion growth region from the controlled. Here we show that an optimal set of parameter values exist in the model which minimizes system damage while, at once, achieving control of lesion growth.

  4. Policy, technology, and management strategies for achieving sustainable agricultural intensification

    Microsoft Academic Search

    David R. Lee; Christopher B. Barrett; John G. McPeak

    2006-01-01

    Considerable agreement exists among researchers, development practitioners, and policymakers regarding the goals of sustainable agricultural intensification (SAI). They include: achieving agricultural productivity growth, household food security, and improved rural livelihoods and employment, while simultaneously mitigating environmental degradation. However, the multiplicity of these objectives, as well as the choice of approaches to achieving them and the site- and context-specificity of specific

  5. Achievement Motivation Development Project. Final Report. Appendix IV, Part 2.

    ERIC Educational Resources Information Center

    McClelland, David C.; Alschuler, Alfred S.

    The Achievement Motivation Development Project is described. The Project has culminated in the development of course materials designed explicitly to promote aspects of psychological growth. As such, it is viewed as but one thrust in an emerging psychological education movement. Achievement motivation is defined as a way of planning, a set of…

  6. Adaptive node placement for Optimal Control

    Microsoft Academic Search

    Ho Ching; Pui-Hang Ko; Ching Kong; Ruxu Du

    2009-01-01

    Optimal control deals with the problem of finding a control law for a given system such that a certain optimality criterion is achieved. Most optimal control problems are sufficiently complex such that numerical methods are necessary to compute a solution. Some of the more prominent works on the numerical optimal control are the discrete mechanics and optimal control (DMOC) method

  7. Thermodynamic analysis and growth of ZnSe single crystals in Zn-Se-I2 system

    NASA Astrophysics Data System (ADS)

    Li, Huanyong; Gu, Zhi; Zhang, Haiyang; Li, Wenwei

    2015-04-01

    A modified chemical vapor transport system is developed to grow ZnSe single crystals from zinc-selenium source materials, where iodine serves as the chemical transport agent to avoid the kinetics limitations of the congruent sublimation conditions. ZnSe crystals with different crystalline quality are obtained under various growth conditions. The thermodynamic properties of Zn-Se-I2 system are studied by combining the mass conservation with the vapor-solid reactions related to crystal growth. The mass transport is analyzed by using the diffusion-convection mathematical model. Depending on initial iodine concentration and the designed temperature difference between source zone and growth zone, the optimum growth conditions can be predicted based on the calculated maximum growth rate. Comparing growth results with theoretical analysis indicates that Zn-Se-I2 system affords a feasible route to grow ZnSe crystals. High quality ZnSe crystal can be achieved under the theoretically optimized growth conditions.

  8. Optimal husbandry of hatchling Eastern Indigo Snakes (Drymarchon couperi) during a captive head-start program.

    PubMed

    Wines, Michael P; Johnson, Valerie M; Lock, Brad; Antonio, Fred; Godwin, James C; Rush, Elizabeth M; Guyer, Craig

    2015-05-01

    Optimal husbandry techniques are desirable for any headstart program, but frequently are unknown for rare species. Here we describe key reproductive variables and determine optimal incubation temperature and diet diversity for Eastern Indigo Snakes (Drymarchon couperi) grown in laboratory settings. Optimal incubation temperature was estimated from two variables dependent on temperature, shell dimpling, a surrogate for death from fungal infection, and deviation of an egg from an ovoid shape, a surrogate for death from developmental anomalies. Based on these relationships and size at hatching we determined optimal incubation temperature to be 26°C. Additionally, we used incubation data to assess the effect of temperature on duration of incubation and size of hatchlings. We also examined hatchling diets necessary to achieve optimal growth over a 21-month period. These snakes exhibited a positive linear relationship between total mass eaten and growth rate, when individuals were fed less than 1711?g of prey, and displayed constant growth for individuals exceeding 1711?g of prey. Similarly, growth rate increased linearly with increasing diet diversity up to a moderately diverse diet, followed by constant growth for higher levels of diet diversity. Of the two components of diet diversity, diet evenness played a stronger role than diet richness in explaining variance in hatchling growth. These patterns document that our goal of satiating snakes was achieved for some individuals but not others and that diets in which total grams consumed over the first 21 months of life is distributed equivalently among at least three prey genera yielded the fastest growth rates for hatchling snakes. Zoo Biol. 34:230-238, 2015. © 2015 Wiley Periodicals Inc. PMID:25866094

  9. ARMY VEHICLE DURABILITY OPTIMIZATION & RELIABILITY

    E-print Network

    Kusiak, Andrew

    ARMY VEHICLE DURABILITY OPTIMIZATION & RELIABILITY How to Optimize the Vehicle Design to Minimize/Reduce the Weight? Under These Uncertainties, How to Achieve Component Level Reliability? Under These Uncertainties, How to Achieve System Level Reliability? Dynamics Analysis FE Model System Model Dynamic Stress

  10. The Impact of Reading Achievement on Overall Academic Achievement

    ERIC Educational Resources Information Center

    Churchwell, Dawn Earheart

    2009-01-01

    This study examined the relationship between reading achievement and achievement in other subject areas. The purpose of this study was to determine if there was a correlation between reading scores as measured by the Standardized Test for the Assessment of Reading (STAR) and academic achievement in language arts, math, science, and social studies…

  11. Predicting Mathematics Achievement: The Influence of Prior Achievement and Attitudes

    ERIC Educational Resources Information Center

    Hemmings, Brian; Grootenboer, Peter; Kay, Russell

    2011-01-01

    Achievement in mathematics is inextricably linked to future career opportunities, and therefore, understanding those factors that influence achievement is important. This study sought to examine the relationships among attitude towards mathematics, ability and mathematical achievement. This examination was also supported by a focus on gender…

  12. Are Degree Achievements Really Achievements? College of Information Studies

    E-print Network

    Lin, Jimmy

    evidence from Mandarin Chinese, I argue that degree achievements without difference values denote punctual English and Mandarin; to explain the complex aspec- tual behavior of degree achievements, my account in a degree achievement and the telicity of the denoted event. While I agree with their basic claim

  13. Excitation-Wavelength Dependent and Time-Resolved Photoluminescence Studies of Europium Doped GaN Grown by Interrupted Growth Epitaxy (IGE)

    E-print Network

    Steckl, Andrew J.

    as a function of Ga shutter cycling time. The overall strongest red Eu3+ PL intensity was obtained from a sample-V compound semiconductors have received significant attention due to their applications in light emittingN thin films. To achieve this goal, the materials need to be optimized for several growth parameters: e

  14. Optimizing the Pattern of Essential Amino Acids as the Sole Source of Dietary Nitrogen Supports Near-Maximal Growth in Kittens1'2'3

    Microsoft Academic Search

    TIMOTHY P. TAYLOR; JAMES G. MORRIS; NEIL H. WILLITS; R. ROGERS

    Most experiments conducted to deter mine the optimal essential amino acid (EAA) nitrogen to total nitrogen (E:T) ratio in rats, chicks and other species have shown that weight gain and nitrogen re tention are optimal when the ratio is between 0.5 and 0.65. Two experiments were conducted to determine if weight gains of kittens fed EAA as a sole source

  15. Gear optimization

    NASA Technical Reports Server (NTRS)

    Vanderplaats, G. N.; Chen, Xiang; Zhang, Ning-Tian

    1988-01-01

    The use of formal numerical optimization methods for the design of gears is investigated. To achieve this, computer codes were developed for the analysis of spur gears and spiral bevel gears. These codes calculate the life, dynamic load, bending strength, surface durability, gear weight and size, and various geometric parameters. It is necessary to calculate all such important responses because they all represent competing requirements in the design process. The codes developed here were written in subroutine form and coupled to the COPES/ADS general purpose optimization program. This code allows the user to define the optimization problem at the time of program execution. Typical design variables include face width, number of teeth and diametral pitch. The user is free to choose any calculated response as the design objective to minimize or maximize and may impose lower and upper bounds on any calculated responses. Typical examples include life maximization with limits on dynamic load, stress, weight, etc. or minimization of weight subject to limits on life, dynamic load, etc. The research codes were written in modular form for easy expansion and so that they could be combined to create a multiple reduction optimization capability in future.

  16. The influence of growth conditions on the microstructure and critical currents of TFA-MOD YBa2Cu3O7 films

    Microsoft Academic Search

    T. Puig; J. C. González; A. Pomar; N. Mestres; O. Castaño; M. Coll; J. Gázquez; F. Sandiumenge; S. Piñol; X. Obradors

    2005-01-01

    The influence of three processing parameters, temperature, gas flow rate and water pressure, on the YBa2Cu3O7 film growth on LaAlO3 single-crystal substrates from trifluoroacetate precursors has been investigated and the optimal film processing conditions to achieve high critical currents have been determined. We have found that the growth conditions maximizing the critical current density are those where the nucleation of

  17. Achieving Developmental Synchrony in Young Children With Hearing Loss

    PubMed Central

    Mellon, Nancy K.; Ouellette, Meredith; Greer, Tracy; Gates-Ulanet, Patricia

    2009-01-01

    Children with hearing loss, with early and appropriate amplification and intervention, demonstrate gains in speech, language, and literacy skills. Despite these improvements many children continue to exhibit disturbances in cognitive, behavioral, and emotional control, self-regulation, and aspects of executive function. Given the complexity of developmental learning, educational settings should provide services that foster the growth of skills across multiple dimensions. Transdisciplinary intervention services that target the domains of language, communication, psychosocial functioning, motor, and cognitive development can promote academic and social success. Educational programs must provide children with access to the full range of basic skills necessary for academic and social achievement. In addition to an integrated curriculum that nurtures speech, language, and literacy development, innovations in the areas of auditory perception, social emotional learning, motor development, and vestibular function can enhance student outcomes. Through ongoing evaluation and modification, clearly articulated curricular approaches can serve as a model for early intervention and special education programs. The purpose of this article is to propose an intervention model that combines best practices from a variety of disciplines that affect developmental outcomes for young children with hearing loss, along with specific strategies and approaches that may help to promote optimal development across domains. Access to typically developing peers who model age-appropriate skills in language and behavior, small class sizes, a co-teaching model, and a social constructivist perspective of teaching and learning, are among the key elements of the model. PMID:20150187

  18. Optimal Contracts for Central Bankers

    Microsoft Academic Search

    Carl E Walsh

    1995-01-01

    This paper adopts a principal-agent framework to determine how a central banker's incentives should be structured to induce the socially optimal policy. In contrast to previous findings using ad hoc targeting rules, the inflation bias of discretionary policy is eliminated and an optimal response to shocks is achieved by the optimal incentive contract, even in the presence of private central-bank

  19. Growth optimization of InAs/GaAs quantum dots and performance enhancement of a GaAs tunnel diode by embedding quantum dots for solar cell application

    NASA Astrophysics Data System (ADS)

    Park, K. W.; Kang, S. J.; Ravindran, Sooraj; Min, J. W.; Lee, S. K.; Lee, Y. T.

    2015-07-01

    We report the performance enhancement of a molecular beam epitaxy grown GaAs tunnel diode embedded with InAs quantum dots (QDs) for tandem solar cell application, and characterization of tunnel diodes embedded with InAs QDs grown with different growth parameters. Prior to the growth and fabrication of the tunnel diode, InAs QDs were grown under different growth durations and temperatures. The InAs QD samples grown in a temperature range from 480 to 520 °C for a duration of 32 s showed the highest areal fill fraction by InAs QDs. Tunnel diodes embedded with InAs QDs that were grown at various growth conditions were fabricated and characterized. We found that the tunnel diode embedded with InAs QD grown at 520 °C showed the highest peak tunnel current density among all the samples. The enhanced performance of the InAs QD embedded tunnel diode is attributed to the large areal fill fraction produced by the presence of large InAs QDs having high density, which are formed at sufficiently high growth temperature and long growth duration.

  20. High Growth Rate Metal-Organic Molecular Beam Epitaxy for the Fabrication of GaAs Space Solar Cells

    NASA Technical Reports Server (NTRS)

    Freundlich, A.; Newman, F.; Monier, C.; Street, S.; Dargan, P.; Levy, M.

    2005-01-01

    In this work it is shown that high quality GaAs photovoltaic devices can be produced by Molecular Beam Epitaxy (MBE) with growth rates comparable to metal-organic chemical vapor deposition (MOCVD) through the subsitution of group III solid sources by metal-organic compounds. The influence the III/V flux-ratio and growth temperatures in maintaining a two dimensional layer by layer growth mode and achieving high growth rates with low residual background impurities is investigated. Finally subsequent to the study of the optimization of n- and p doping of such high growth rate epilayers, results from a preliminary attempt in the fabrication of GaAs photovoltaic devices such as tunnel diodes and solar cells using the proposed high growth rate approach are reported.

  1. Metalorganic chemical vapor deposition growth of high optical quality and high mobility GaN

    Microsoft Academic Search

    B. P. Keller; S. Keller; D. Kapolnek; W. N. Jiang; Y. F. Wu; H. Masui; X. Wu; B. Heying; J. S. Speck; U. K. Mishra; S. P. Denbaars

    1995-01-01

    Hall mobilities as high as 702 and 1230 cm2\\/Vs at 300 and 160K along with low dislocation densities of 4.0 ? 108 cm-2 have been achieved in GaN films grown on sapphire by metalorganic chemical vapor deposition. High growth temperatures have\\u000a been established to be crucial for optimal GaN film quality. Photoluminescence measurements revealed a low intensity of the\\u000a deep

  2. CCMR: Characterizing Growth of Single Cell Amoeba

    NSDL National Science Digital Library

    Yavitt, Ben

    2010-08-15

    This summer, I worked on developing methods and protocols for studying the vegetative growth cycle of the social amoeba Dictyostelium discoideum. With my collaborators, we conducted experiments that optimized our ability to monitor the amoeba’s different growth phases.

  3. Environmental optimal control strategies based on plant canopy photosynthesis responses and greenhouse climate model

    NASA Astrophysics Data System (ADS)

    Deng, Lujuan; Xie, Songhe; Cui, Jiantao; Liu, Tao

    2006-11-01

    It is the essential goal of intelligent greenhouse environment optimal control to enhance income of cropper and energy save. There were some characteristics such as uncertainty, imprecision, nonlinear, strong coupling, bigger inertia and different time scale in greenhouse environment control system. So greenhouse environment optimal control was not easy and especially model-based optimal control method was more difficult. So the optimal control problem of plant environment in intelligent greenhouse was researched. Hierarchical greenhouse environment control system was constructed. In the first level data measuring was carried out and executive machine was controlled. Optimal setting points of climate controlled variable in greenhouse was calculated and chosen in the second level. Market analysis and planning were completed in third level. The problem of the optimal setting point was discussed in this paper. Firstly the model of plant canopy photosynthesis responses and the model of greenhouse climate model were constructed. Afterwards according to experience of the planting expert, in daytime the optimal goals were decided according to the most maximal photosynthesis rate principle. In nighttime on plant better growth conditions the optimal goals were decided by energy saving principle. Whereafter environment optimal control setting points were computed by GA. Compared the optimal result and recording data in real system, the method is reasonable and can achieve energy saving and the maximal photosynthesis rate in intelligent greenhouse

  4. Affective Processes and Academic Achievement.

    ERIC Educational Resources Information Center

    Feshbach, Norma Deitch; Feshbach, Seymour

    1987-01-01

    Data indicate that for girls, affective dispositional factors (empathy, depressive affectivity, aggression, and self-concept) are intimately linked to cognitive development and academic achievement. (PCB)

  5. Taurine supplementation of plant derived protein 1 and n-3 fatty acids are critical for optimal growth and development of cobia, rachycentron canadum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We examined growth performance and lipid content in juvenile cobia, Rachycentron canadum, fed a taurine supplemented (1.5%), plant protein based diet with two fish oil replacements. The first fish oil replacement was a thraustochytrid meal (TM+SOY) plus soybean oil (~9% CL) and the second was a cano...

  6. Achieving Better Building Performance and Savings Using Optimal Control Strategies

    E-print Network

    Chen, H.; Deng, S.; Bruner, H.

    2003-01-01

    (DDC). This algorithm is based on mathematical models for the chillers, boilers, chilled and hot water pumps, and air handler fans that relate the power of these components as a function of the chilled water and hot water differential temperature...

  7. Optimizing Production of Hydroquinone Achieves Increased Yield and Energy Efficiency 

    E-print Network

    Gross, S.

    2010-01-01

    Recent experimental and simulation studies -conducted at the Department of Petroleum Engineering at Texas A&M University - confirm oil production is accelerated when propane is used as an additive during steam injection. ...

  8. Hybrid swarm intelligence optimization approach for optimal data storage position identification in wireless sensor networks.

    PubMed

    Mohanasundaram, Ranganathan; Periasamy, Pappampalayam Sanmugam

    2015-01-01

    The current high profile debate with regard to data storage and its growth have become strategic task in the world of networking. It mainly depends on the sensor nodes called producers, base stations, and also the consumers (users and sensor nodes) to retrieve and use the data. The main concern dealt here is to find an optimal data storage position in wireless sensor networks. The works that have been carried out earlier did not utilize swarm intelligence based optimization approaches to find the optimal data storage positions. To achieve this goal, an efficient swam intelligence approach is used to choose suitable positions for a storage node. Thus, hybrid particle swarm optimization algorithm has been used to find the suitable positions for storage nodes while the total energy cost of data transmission is minimized. Clustering-based distributed data storage is utilized to solve clustering problem using fuzzy-C-means algorithm. This research work also considers the data rates and locations of multiple producers and consumers to find optimal data storage positions. The algorithm is implemented in a network simulator and the experimental results show that the proposed clustering and swarm intelligence based ODS strategy is more effective than the earlier approaches. PMID:25734182

  9. Hybrid Swarm Intelligence Optimization Approach for Optimal Data Storage Position Identification in Wireless Sensor Networks

    PubMed Central

    Mohanasundaram, Ranganathan; Periasamy, Pappampalayam Sanmugam

    2015-01-01

    The current high profile debate with regard to data storage and its growth have become strategic task in the world of networking. It mainly depends on the sensor nodes called producers, base stations, and also the consumers (users and sensor nodes) to retrieve and use the data. The main concern dealt here is to find an optimal data storage position in wireless sensor networks. The works that have been carried out earlier did not utilize swarm intelligence based optimization approaches to find the optimal data storage positions. To achieve this goal, an efficient swam intelligence approach is used to choose suitable positions for a storage node. Thus, hybrid particle swarm optimization algorithm has been used to find the suitable positions for storage nodes while the total energy cost of data transmission is minimized. Clustering-based distributed data storage is utilized to solve clustering problem using fuzzy-C-means algorithm. This research work also considers the data rates and locations of multiple producers and consumers to find optimal data storage positions. The algorithm is implemented in a network simulator and the experimental results show that the proposed clustering and swarm intelligence based ODS strategy is more effective than the earlier approaches. PMID:25734182

  10. Optimal Operation of Cascade Hydropower Plants

    Microsoft Academic Search

    Shenglian Guo; Xiang Li; Pan Liu; Fuqiang Guo

    2009-01-01

    A new model is presented based on combined guide curves for optimizing hydropower production and for better storage distribution among cascade reservoirs. The model is optimized with the particle swarm optimization algorithm and storage distribution among cascade reservoirs is achieved by the storage effectiveness index method. The model is applied to the Qingjiang cascade hydropower plants and optimized combined reservoir

  11. OF ACHIEVEMENT Trends in International

    E-print Network

    Huang, Jianyu

    20YEARS OF ACHIEVEMENT TRENDS Trends in International Mathematics and Science Study TIMSS Advanced assessment framework covers algebra, calculus, and geometry in advanced mathematics. In physics, it covers achievement at the fourth and eighth grades. TIMSS 2015 will be the sixth assessment, resulting in a 20-year

  12. Asperger Syndrome and Academic Achievement.

    ERIC Educational Resources Information Center

    Griswold, Deborah E.; Barnhill, Gena P.; Myles, Brenda Smith; Hagiwara, Taku; Simpson, Richard L.

    2002-01-01

    A study focused on identifying the academic characteristics of 21 children and youth who have Asperger syndrome. Students had an extraordinary range of academic achievement scores, extending from significantly above average to far below grade level. Lowest achievement scores were shown for numerical operations, listening comprehension, and written…

  13. Teaming and Achievement. Research Brief

    ERIC Educational Resources Information Center

    Muir, Mike

    2003-01-01

    Teaming is certainly being pointed to as a strategy to improve learning for at risk students. Whether teaming is actually effective at improving student achievement seems to have mixed findings. Some studies find no significant differences for reading, math, science, and social studies achievement, where others state "evidence abounds suggesting…

  14. General Achievement Trends: Rhode Island

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  15. Stress Correlates and Academic Achievement.

    ERIC Educational Resources Information Center

    Bentley, Donna Anderson; And Others

    An ongoing concern for educators is the identification of factors that contribute to or are associated with academic achievement; one such group of variables that has received little attention are those involving stress. The relationship between perceived sources of stress and academic achievement was examined to determine if reactions to stress…

  16. Junior Achievement Middle Grades Program

    NSDL National Science Digital Library

    JA Worldwide

    Junior Achievement has several highly effective programs for middle grade and junior high school students that reinforce the value of education and teach students about the future economic benefits of staying in school. This part of the Junior Achievement site presents them along with lesson plans and suggestions for each of the program areas. There's a Spanish version too.

  17. Optimizing the water chemistry of the Novovoronezh NPP Units 3 and 4 to prevent growth of coolant pressure difference across the reactor

    NASA Astrophysics Data System (ADS)

    Kritskii, V. G.; Rodionov, Yu. A.; Berezina, I. G.; Zelenina, E. V.; Gavrilov, A. V.; Vitkovskii, S. L.; Shchedrin, M. G.; Galanin, A. V.; Gorburov, V. I.

    2014-02-01

    For a few fuel campaigns in the first years of their extended service life, the Novovoronezh NPP Units 3 and 4 had to operate with a limited reactor thermal power output due to constraints imposed on certain parameters of the reactor core. The decrease of thermal power output during a campaign was accompanied by a growth of pressure difference across the reactor caused by accumulation of deposits in the fuel assemblies, which in turn led to a growth in the number of leaky fuel rods. Compensating measures were implemented based on the results obtained from the performed investigations and modeling of corrosion product mass transfer processes, which in the final analysis made it possible to minimize the accumulation of deposits in fuel assemblies and loss of fuel rod tightness, and to exclude the need to limit the reactor thermal power as demanded by constraints imposed on the reactor core parameters.

  18. The htrA (degP) Gene of Listeria monocytogenes 10403S Is Essential for Optimal Growth under Stress Conditions

    Microsoft Academic Search

    Laura D. Wonderling; Brian J. Wilkinson; Darrell O. Bayles

    2004-01-01

    This report describes a mutant of Listeria monocytogenes strain 10403S (serotype 1\\/2a) with a defective response to conditions of high osmolarity, an environment that L. monocytogenes encounters in some ready- to-eat foods. A library of L. monocytogenes clones mutagenized with Tn917 was generated and scored for sensitivity to 4% NaCl in order to identify genes responsible for growth or survival

  19. Risk assessment of the use of sub-optimal levels of weak-acid preservatives in the control of mould growth on bakery products

    Microsoft Academic Search

    S Mar??n; M. E Guynot; P Neira; M Bernadó; V Sanchis; A. J Ramos

    2002-01-01

    The hurdle technology approach was used to prevent fungal growth of common contaminants of bakery products including isolates belonging to the genera Eurotium, Aspergillus and Penicillium. Several levels (0.003%, 0.03% and 0.3%) of calcium propionate, potassium sorbate and sodium benzoate were assayed on a model agar system in a full-factorial experimental design in which the other factors assayed were pH

  20. High volumetric yields of functional dimeric miniantibodies in Escherichia coli , using an optimized expression vector and high-cell-density fermentation under non-limited growth conditions

    Microsoft Academic Search

    U. Horn; W. Strittmatter; A. Krebber; U. Knüpfer; M. Kujau; R. Wenderoth; K. Müller; S. Matzku; A. Plückthun; D. Riesenberg

    1996-01-01

    Functional bivalent miniantibodies, directed against the epidermal growth factor receptor, accumulated to more than 3 gl?1 in high-cell-density cultures of Escherichia coli RV308(pHKK) on a pilot scale. The miniantibodies consist of scFv fragments with a C-termi-nal hinge followed by a helix-turn-helix\\u000a motif, which homodimerizes in vivo. The improved expression vector pHKK is characterized by the hok\\/sok suicide system, improving plasmid

  1. Optimization of growth inducing factors for colony forming and attachment of bone marrow-derived mesenchymal stem cells regarding bioengineering application

    PubMed Central

    Quan, Hongxuan; Kim, Seong-Kyun; Heo, Seong-Joo; Koak, Jai-Young

    2014-01-01

    PURPOSE These days, mesenchymal stem cells (MSCs) have received worldwide attention because of their potentiality in tissue engineering for implant dentistry. The purpose of this study was to evaluate various growth inducing factors in media for improvement of acquisition of bone marrow mesenchymal stem cells (BMMSCs) and colony forming unit-fibroblast (CFU-F). MATERIALS AND METHODS The mouse BMMSCs were freshly obtained from female C3H mouse femur and tibia. The cells seeded at the density of 106/dish in media supplemented with different density of fetal bovine serum (FBS), 1?, 25-dihydroxyvitamin (VD3) and recombinant human epidermal growth factor (rhEGF). After 14 days, CFU-F assay was conducted to analyze the cell attachment and proliferation, and moreover for VD3, the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay was additionally conducted. RESULTS The cell proliferation was increased with the increase of FBS concentration (P<.05). The cell proliferation was highest at the density of 20 ng/mL rhEGF compared with 0 ng/mL and 200 ng/mL rhEGF (P<.05). For VD3, although the colony number was increased with the increase of its concentration, the difference was not statistically significant (P>.05). CONCLUSION FBS played the main role in cell attachment and growth, and the growth factor like rhEGF played the additional effect. However, VD3 did not have much efficacy compare with the other two factors. Improvement of the conditions could be adopted to acquire more functional MSCs to apply into bony defect around implants easily. PMID:25352960

  2. Classroom Order and Student Learning in Late Elementary School: A Multilevel Transactional Model of Achievement Trajectories

    ERIC Educational Resources Information Center

    Gaskins, Clare S.; Herres, Joanna; Kobak, Roger

    2012-01-01

    This study examines the association between classroom order in 4th and 5th grades and student achievement growth over a school year. A three level transactional model tested the effects of classroom order on students' rates of growth in math and reading during the school year controlling for starting achievement levels, student risk factors, and…

  3. Behavioral Engagement in Learning and Math Achievement over Kindergarten: A Contextual Analysis

    ERIC Educational Resources Information Center

    Robinson, Keith; Mueller, Anna S.

    2014-01-01

    Using nationally representative data on 12,462 kindergarten children, this report examines the link between behavioral engagement and math achievement growth during kindergarten. Multilevel models show that students with higher individual engagement tend to experience larger math achievement growth over kindergarten, that classroom engagement…

  4. The Impact of Assessment for Learning: Benefits and Barriers to Student Achievement

    ERIC Educational Resources Information Center

    Collins, Natalie M.

    2012-01-01

    The purpose of this study was to compare growth in student achievement of students in a classroom where the assessment for learning process was either absent from or present in a teacher's practices, and to gather the teacher's and students' perceptions of the benefits and barriers related to growth in student achievement when the…

  5. Reliability growth modeling and optimal release policy under fuzzy environment of an N-version programming system incorporating the effect of fault removal efficiency

    Microsoft Academic Search

    P. K. Kapur; Anshu Gupta; P. C. Jha

    2007-01-01

    Failure of a safety critical system can lead to big losses. Very high software reliability is required for automating the\\u000a working of systems such as aircraft controller and nuclear reactor controller software systems. Fault-tolerant softwares are\\u000a used to increase the overall reliability of software systems. Fault tolerance is achieved using the fault-tolerant schemes\\u000a such as fault recovery (recovery block scheme),

  6. Understanding seedling growth relationships through specific leaf area and leaf nitrogen concentration: generalisations across growth forms and growth irradiance

    Microsoft Academic Search

    Ian J. Wright; Mark Westoby

    2001-01-01

    Seedling relative growth rate (RGR) achieved under favourable growth conditions can be thought of as a useful bioassay of the potential ability of species to take advantage of favourable growth opportunities; that is, of a species' growth strategy. The consistency of relationships between RGR and its component attributes leaf nitrogen productivity (LNP), leaf N per area (LNCa), specific leaf area

  7. [Optimization of oxytetracycline biosynthesis].

    PubMed

    Maksimova, E A; Falkov, N N; Izma?lov, N N; Romanchuk, N N

    1988-06-01

    It was shown that rising of temperature up to 30 degrees C at the stage of the oxytetracycline-producing organism growth promoted acceleration of the culture growth rate and increasing of the antibiotic concentration by the 114th hour of the biosynthetic process. For the apparatus used in the study optimal aeration and agitation conditions were developed. To provide optimal parameters during biosynthesis of oxytetracycline, it was recommended to use the aeration rate of 1 v/v.min and the specific mechanical power for mixing of not less than 1 kW/m3. PMID:3421763

  8. The arithmetic of achieving universal primary education

    NASA Astrophysics Data System (ADS)

    Fredrisken, Birger

    1983-06-01

    In spite of an enrolment growth during the past two decades unparalleled in history, the battle to reach universal primary education (UPE) is still far from won for most developing countries (DC). High population growth and persistent high levels of repetition and drop-out contribute to the elusiveness of this target. About half the 142% primary school enrolment increase achieved between 1960 and 1980 was required just to keep pace with population growth. Repetition consumes about 15% of the DC's primary school capacity and about 40% of those starting Grade 1 drop out prior to Grade 4. Net of repetition, the DC had in 1980 an enrolment capacity corresponding to about 3/4 of their children of primary school age. While the capacity for new admission almost equalled the size of the population of admission age, because of high drop-out and repetition, the number of non-repeaters enrolled in the final grade of the cycle was only about half that of the corresponding population age-group. Maintaining present levels of repetition, the DC would have to more than double their 1980 enrolment to attain UPE by the year 2000. Therefore, in view of the present economic crisis, it is likely that many DC will enter the 21st century without having reached this target.

  9. Entropy, environment, and endogenous economic growth

    Microsoft Academic Search

    Sjak Smulders

    1995-01-01

    This paper investigates the proper modeling of the interaction between economic growth and environmental problems, summarizes under which conditions unlimited economic growth with limited natural resources is feasible, and describes how sustainable growth can be achieved. It synthesizes the results from various environmental endogenous growth models.

  10. Optimized solar module design

    NASA Technical Reports Server (NTRS)

    Santala, T.; Sabol, R.; Carbajal, B. G.

    1978-01-01

    The minimum cost per unit of power output from flat plate solar modules can most likely be achieved through efficient packaging of higher efficiency solar cells. This paper outlines a module optimization method which is broadly applicable, and illustrates the potential results achievable from a specific high efficiency tandem junction (TJ) cell. A mathematical model is used to assess the impact of various factors influencing the encapsulated cell and packing efficiency. The optimization of the packing efficiency is demonstrated. The effect of encapsulated cell and packing efficiency on the module add-on cost is shown in a nomograph form.

  11. Growth after renal transplantation

    Microsoft Academic Search

    Jérôme Harambat; Pierre Cochat

    2009-01-01

    Growth may be severely impaired in children with chronic renal insufficiency. Since short stature can have major consequences\\u000a on quality of life and self-esteem, achieving a ‘normal’ height is a crucial issue for renal transplant recipients. However,\\u000a despite successful renal transplantation, the final height attained by most recipients is not the calculated target height.\\u000a Catch-up growth spurts post-transplantation are usually

  12. Deploying wireless sensors to achieve both coverage and connectivity

    Microsoft Academic Search

    Xiaole Bai; Santosh Kumar; Dong Xuan; Ziqiu Yun; Ten-hwang Lai

    2006-01-01

    It is well-known that placing disks in the triangular lattice pat- tern is optimal for achieving full coverage on a plane. With the emergence of wireless sensor networks, however, it is now no longer enough to consider coverage alone when deploy- ing a wireless sensor network; connectivity must also be con- sidered. While moderate loss in coverage can be tolerated

  13. Revision of Achievement Goal Theory: Necessary and Illuminating.

    ERIC Educational Resources Information Center

    Harackiewicz, Judith M.; Barron, Kenneth E.; Pintrich, Paul R.; Elliot, Andrew J.; Thrash, Todd M.

    2002-01-01

    Discusses three reasons to revise achievement goal theory: the importance of separating approach from avoidance strivings, the positive potential of performance-approach goals, and identification of the ways performance-approach goals can combine with mastery approach goals to promote optimal motivation. Reviews theory and research to substantiate…

  14. Visual Arts and Academic Achievement

    E-print Network

    Gibson, Marcia A.; Larson, Meredith A

    2007-01-01

    Learn Style Intrinsic Intelligences Emotional InstrumentalTheory Intelligences Learn style Emotional Parent --intelligence (Gardner, 1999) and need to be able to develop their skills in that domain to achieve self-confidence, emotional

  15. Class, Race, and Educational Achievement

    Microsoft Academic Search

    Brenda X. Mejia-Smith; Edmund W. Gordon

    \\u000a The relationship between class, race, and educational achievement has been a focus of considerable research attention and\\u000a debate concerning educational policy and practice for most of the past century. The literature, however, has generally neglected\\u000a to discuss how race, class, and educational achievement are intertwined. The related issues have been difficult to untwine\\u000a and understand because of their embeddedness in

  16. Plant phototropic growth.

    PubMed

    Fankhauser, Christian; Christie, John M

    2015-05-01

    Plants are photoautotrophic sessile organisms that use environmental cues to optimize multiple facets of growth and development. A classic example is phototropism - in shoots this is typically positive, leading to growth towards the light, while roots frequently show negative phototropism triggering growth away from the light. Shoot phototropism optimizes light capture of leaves in low light environments and hence increases photosynthetic productivity. Phototropins are plasma-membrane-associated UV-A/blue-light activated kinases that trigger phototropic growth. Light perception liberates their protein kinase domain from the inhibitory action of the amino-terminal photosensory portion of the photoreceptor. Following a series of still poorly understood events, phototropin activation leads to the formation of a gradient of the growth hormone auxin across the photo-stimulated stem. The greater auxin concentration on the shaded compared with the lit side of the stem enables growth reorientation towards the light. In this Minireview, we briefly summarize the signaling steps starting from photoreceptor activation until the establishment of a lateral auxin gradient, ultimately leading to phototropic growth in shoots. PMID:25942556

  17. Optimization of the Growth Conditions for Molecular Beam Epitaxy of MgxZn1-xO (0?x?0.12) Films on Zn-Polar ZnO Substrates

    NASA Astrophysics Data System (ADS)

    Yuji, Hiroyuki; Nakahara, Ken; Tamura, Kentaro; Akasaka, Shunsuke; Nishimoto, Yoshio; Takamizu, Daiju; Onuma, Takeyoshi; Chichibu, Shigefusa F.; Tsukazaki, Atsushi; Ohtomo, Akira; Kawasaki, Masashi

    2010-07-01

    We report on optimization of the growth conditions for MgxZn1-xO (x=0,0.04,0.05,0.12) thin films grown on c-plane Zn-polar ZnO single crystal substrates by using plasma-assisted molecular beam epitaxy (PAMBE). A normal vector to the ZnO substrate surfaces was angled at 0.5±0.1° off from the [0001] c-axis toward the [1100] direction, leading to a stable step-and-terrace structure. A growth temperature (Tg) higher than 800 °C led to the ZnO films presenting the first excited state luminescence of A-free excitons in photoluminescence (PL) spectra at 12 K. A Tg higher than 800 °C enhanced optical attributes of a MgxZn1-xO film. The longest PL lifetime of fast-decay components reached 3.5 ns in time-resolved PL measurement for an Mg0.12Zn0.88O film grown at 900 °C, indicating a concentration of nonradiative recombination centers is substantially eliminated compared to the previously reported PL lifetime of 60 ps for an Mg0.11Zn0.89O film grown by pulsed laser deposition.

  18. Plant-atmosphere interactions and effects of elevated carbon dioxide on growth and photosynthesis of black cottonwood at ambient and optimal nutrient supply

    SciTech Connect

    Thorgeirsson, H.; Sigurdsson, B.D. [Agricultural Research Institute, Reykjavik (Iceland)

    1995-06-01

    In 1990 a 14 ha stand of black cottonwood was planted on an exposed site in Gunnarsholt in south Iceland to investigate the long-term modification of microclimate as tree canopy develops on an exposed site and the effects of microclimate on tree physiology and growth. The homogenous treeless surroundings of the site provide excellent fetch and meet the most stringent criteria of energy balance models. Site energy balance is partitioned using the Bowen ratio approach based on data from both a reversing temperature difference measurement system and a fixed profile system. Key characteristics of the site energy balance and microclimate will be presented. In the beginning of the 1994 growing season a five-year study of the interaction between nutrient supply and elevated carbon dioxide was initiated using sixteen trees enclosed individually in chambers and given either 350 or 700 ppm carbon dioxide and either ambient or optimum nutrition in a randomized block design. Reference trees are used to determine the effect of the chambers which is significant on exposed sites due to sheltering effects. Growth of the trees was monitored non-destructively. Photosynthetic rates, light response and A/C{sub i} curves were determined on selected leaves. Examples of results from the first growing season will be presented.

  19. Conserved histidine of metal transporter AtNRAMP1 is crucial for optimal plant growth under manganese deficiency at chilling temperatures.

    PubMed

    Ihnatowicz, Anna; Siwinska, Joanna; Meharg, Andrew A; Carey, Manus; Koornneef, Maarten; Reymond, Matthieu

    2014-06-01

    Manganese (Mn) is an essential nutrient required for plant growth, in particular in the process of photosynthesis. Plant performance is influenced by various environmental stresses including contrasting temperatures, light or nutrient deficiencies. The molecular responses of plants exposed to such stress factors in combination are largely unknown. Screening of 108 Arabidopsis thaliana (Arabidopsis) accessions for reduced photosynthetic performance at chilling temperatures was performed and one accession (Hog) was isolated. Using genetic and molecular approaches, the molecular basis of this particular response to temperature (G × E interaction) was identified. Hog showed an induction of a severe leaf chlorosis and impaired growth after transfer to lower temperatures. We demonstrated that this response was dependent on the nutrient content of the soil. Genetic mapping and complementation identified NRAMP1 as the causal gene. Chlorotic phenotype was associated with a histidine to tyrosine (H239Y) substitution in the allele of Hog NRAMP1. This led to lethality when Hog seedlings were directly grown at 4°C. Chemical complementation and hydroponic culture experiments showed that Mn deficiency was the major cause of this G × E interaction. For the first time, the NRAMP-specific highly conserved histidine was shown to be crucial for plant performance. PMID:24571269

  20. Metabolic efficiency underpins performance trade-offs in growth of Arabidopsis thaliana.

    PubMed

    Kleessen, Sabrina; Laitinen, Roosa; Fusari, Corina M; Antonio, Carla; Sulpice, Ronan; Fernie, Alisdair R; Stitt, Mark; Nikoloski, Zoran

    2014-01-01

    Growth often involves a trade-off between the performance of contending tasks; metabolic plasticity can play an important role. Here we grow 97 Arabidopsis thaliana accessions in three conditions with a differing supply of carbon and nitrogen and identify a trade-off between two tasks required for rosette growth: increasing the physical size and increasing the protein concentration. We employ the Pareto performance frontier concept to rank accessions based on their multitask performance; only a few accessions achieve a good trade-off under all three growth conditions. We determine metabolic efficiency in each accession and condition by using metabolite levels and activities of enzymes involved in growth and protein synthesis. We demonstrate that accessions with high metabolic efficiency lie closer to the performance frontier and show increased metabolic plasticity. We illustrate how public domain data can be used to search for additional contending tasks, which may underlie the sub-optimality in some accessions. PMID:24675291

  1. Sociodemographic Moderators of Middle School Transition Effects on Academic Achievement

    ERIC Educational Resources Information Center

    Akos, Patrick; Rose, Roderick A.; Orthner, Dennis

    2015-01-01

    The academic impact of the transition from elementary to middle school has significant consequences for many early adolescents. This study examines academic growth across the transition, as well as sociodemographic moderators. Rather than defining the transition effect as a decline in student achievement between fifth and sixth grade, these data…

  2. Hall of Black Achievement Gallery

    NSDL National Science Digital Library

    A project of Bridgewater State College, the Hall of Black Achievement (HOBA). is a repository of the significant achievements and contributions of African Americans, Cape Verdeans, and Hispanics of African descent. The mission of the HOBA is to "discover, detail, and disclose the significant achievements and contributions of people of color." HOBA also serves as a forum for research, discussion, and analysis of the significant contributions that people of color continue to make to this country and beyond. The Web site now features a gallery of the historical figures inducted into the HOBA and chronicles their lives, contributions, and the period of history in which they lived. Audio narratives can be heard with RealPlayer.

  3. The Effects of Temperature and Nutritional Conditions on Mycelium Growth of Two Oyster Mushrooms (Pleurotus ostreatus and Pleurotus cystidiosus)

    PubMed Central

    Hoa, Ha Thi

    2015-01-01

    The influences of temperature and nutritional conditions on the mycelium growth of oyster mushroom Pleurotus ostreatus (PO) and Pleurotus cystidiosus (PC) were investigated in laboratory experiment during the summer season of 2014. The results of the experiment indicated that potato dextrose agar (PDA) and yam dextrose agar (YDA) were the most suitable media for the mycelium growth of oyster mushroom PO while four media (PDA, YDA, sweet potato dextrose agar, and malt extract agar medium) were not significantly different in supporting mycelium growth of oyster mushroom PC. The optimal temperature for mycelium growth of both oyster mushroom species was obtained at 28?. Mycelium growth of oyster mushroom PO was improved by carbon sources such as glucose, molasses, and at 1~5% sucrose concentration, mycelium colony diameter of mushroom PO was achieved the highest value. Whereas glucose, dextrose, and sucrose as carbon sources gave the good mycelium growth of oyster mushroom PC, and at 1~3% sucrose concentration, mycelium colony diameter of PC was achieved the maximum value. Ammonium chloride concentrations at 0.03~0.09% and 0.03~0.05% also gave the greatest values in mycelium colony diameter of mushroom PO and PC. Brown rice was found to be the most favourable for mycelium growth of two oyster mushroom species. In addition, sugarcane residue, acasia sawdust and corn cob were selected as favourable lignocellulosic substrate sources for mycelium growth of both oyster mushrooms. PMID:25892910

  4. Greenhouse gas growth rates

    Microsoft Academic Search

    James Hansen; Makiko Sato

    2004-01-01

    We posit that feasible reversal of the growth of atmospheric CH4 and other trace gases would provide a vital contribution toward averting dangerous anthropogenic interference with global climate. Such trace gas reductions may allow stabilization of atmospheric CO2 at an achievable level of anthropogenic CO2 emissions, even if the added global warming constituting dangerous anthropogenic interference is as small as

  5. Growth and characterization of group iiinitrides by migration-enhanced afterglow epitaxy

    NASA Astrophysics Data System (ADS)

    Gergova, Rositsa

    The work presented in this thesis investigates the growth and properties of group III- nitride semiconductors that were grown using the Migration Enhanced Afterglow Epitaxy (MEAglow) method. This work was to enhance the understanding of the MEAglow growth process towards the improvement of quality of the layers grown using this technique. The MEAglow technique applies the migration enhanced epitaxy method in a low pressure plasma-based CVD reactor, which has a potential of producing high quality epitaxial group III-nitride layers at relatively low growth temperatures on large deposition areas. The low temperature pulse growth in metal-rich regime, comprising the MME method was employed under growth pressures between 500 mTorr and 3000 mTorr. As the MME method up to this point has been used only for MBE systems, study of the impact of the growth pressure on the materials properties was necessary. In this work the pressure dependence was mapped to an existing surface phase diagram for MBE systems by calculating the number of nitrogen gas phase collisions and the metalorganic bombardment rate, for the specific to the prototype reactor parameters, to a first approximation. This was done in order to achieve an intermediate regime free of metal droplets for growth in metal-rich regime. High quality epitaxial InN layers were accomplished on extremely thin and smooth Ga2O3 buffer layers. These results indicate a potential for the application of Ga2O3 buffers in InN growth. The MEAglow InN layers were further optimized for growth on commercially available GaN buffer layers and excellent two-dimensional growth was achieved for layers grown under metal-rich conditions at 512 °C. Post-growth annealing studies were carried out for InN layers grown at temperatures below 400 °C to study the limiting processes of the removal of excess nitrogen, believed to be a dominant defect in InN films grown in plasma-based systems at very low temperatures. Variations in GaN stoichiometry under certain growth conditions and the effect of similar growth conditions on MEAglow grown InGaN were also examined. The growth of MEAglow InGaN samples on sapphire substrates was optimized to reduce the indium surface segregation and phase separation of the material.

  6. Teachers, Schools, and Academic Achievement

    Microsoft Academic Search

    Steven G. Rivkin; Eric A. Hanushek; John F. Kain

    2005-01-01

    This paper disentangles the impact of schools and teachers in influencing achievement with special attention given to the potential problems of omitted or mismeasured variables and of student and school selection. Unique matched panel data from the UTD Texas Schools Project permit the identification of teacher quality based on student performance along with the impact of specific, measured components of

  7. Teachers, Schools, and Academic Achievement

    Microsoft Academic Search

    Steven G. Rivkin; Eric A. Hanushek; John F. Kain

    2002-01-01

    This paper disentangles the impact of schools and teachers in influencing achievement with special attention given to the potential problems of omitted or mismeasured variables and of student and school selection. Unique matched panel data from the UTD Texas Schools Project permit the identification of teacher quality based on student performance along with the impact of specific, measured components of

  8. The Achievement-Assessment Link

    ERIC Educational Resources Information Center

    Wallace, Virginia; Husid, Whitney

    2011-01-01

    The recent recession, school budget cuts, and predictions of school libraries' demise because of technology advances put pressure on school librarians to prove the utility, relevance, and value of school libraries to student learning. While national studies document that school libraries increase student achievement, school librarians must…

  9. Teacher Anxiety and Student Achievement.

    ERIC Educational Resources Information Center

    Galbo, Joseph J.

    1983-01-01

    This review focuses on the influence of teacher anxiety on student achievement and suggests directions for further inquiry. Research has determined no mutually acceptable definition of teacher anxiety, therefore a variety of its aspects are examined, including teacher effectiveness and influence upon classroom climate.

  10. Attribution Theory in Science Achievement

    ERIC Educational Resources Information Center

    Craig, Martin

    2013-01-01

    Recent research reveals consistent lags in American students' science achievement scores. Not only are the scores lower in the United States compared to other developed nations, but even within the United States, too many students are well below science proficiency scores for their grade levels. The current research addresses this problem by…

  11. Academic Achievement in Effective Schools

    ERIC Educational Resources Information Center

    Basque, Marc; Bouchamma, Yamina

    2013-01-01

    Purpose: The purpose of this study is to identify predictors of achievement in mathematics in elementary schools in New Brunswick (Canada). Data Collection: Both teachers and school leaders (N = 111) completed a questionnaire on their practices and on school functioning. Findings: Multiple regression analyses revealed that the students'…

  12. Steps toward Promoting Cognitive Achievements.

    ERIC Educational Resources Information Center

    Winne, Philip H.

    This paper contends that efforts at educational reform must focus, above all, on the instructional encounter between teachers and students. The argument is presented in triadic sequence: three basic assumptions about learning, three interrelated models of the instructional process, and three practical approaches to promoting cognitive achievement.…

  13. Achieving NTRU with Montgomery Multiplication

    E-print Network

    Achieving NTRU with Montgomery Multiplication Colleen O'Rourke and Berk Sunar, Member, IEEE Abstract--In this paper, we propose a new unified architecture that utilizes the Montgomery Multiplication algorithm to perform a modular multiplication for both integers and binary polynomials and NTRU's polynomial

  14. Student Achievement, 1986-87.

    ERIC Educational Resources Information Center

    Mangino, Evangelina

    This report summarizes results of student achievement in the Austin (Texas) Independent School District (AISD) on the Texas Educational Assessment of Minimum Skills (TEAMS) tests in 1986-87. Major findings indicate the following: (1) 99.4% of AISD seniors to graduate in May 1987 passed the Exit-Level TEAMS tests, with only 17 denied diplomas in…

  15. INSTRUCTIONAL MATERIALS FOR LOW ACHIEVERS.

    ERIC Educational Resources Information Center

    BRAZZIEL, WILLIAM F.

    CULTURALLY DISADVANTAGED CHILDREN CAN LEARN WELL WHEN THEY ARE OFFERED A REALISTIC CURRICULUM AND REALISTIC MATERIALS OF INSTRUCTION. EDUCATIONAL DEMANDS FROM PRESCHOOL THROUGH ADULT EDUCATION REQUIRE DIFFERENT INSTRUCTIONAL MATERIALS TO PROPERLY EDUCATE LOW ACHIEVERS REGARDLESS OF THEIR BACKGROUNDS. PUBLISHERS SHOULD AID THE COMMUNITY IN THEIR…

  16. School Desegregation and Black Achievement.

    ERIC Educational Resources Information Center

    Cook, Thomas; And Others

    Seven papers commissioned by the National Institute of Education in order to clarify the state of recent knowledge about the effects of school desegregation on the academic achievement of black students are contained in this report. The papers, which analyze 19 "core" empirical studies on this topic, include: (1) "What Have Black Children Gained…

  17. Socioeconomic Determinants of Academic Achievement

    ERIC Educational Resources Information Center

    Tomul, Ekber; Savasci, Havva Sebile

    2012-01-01

    This study aims to investigate the relationship between academic achievement and the socioeconomic characteristics of elementary school 7th grade students in Burdur. The population of the study are 7th grade students who had education at elementary schools in Burdur in the 2007-2008 academic year. Two staged sampling was chosen as suitable for the…

  18. Teacher Dispositions and Student Achievement

    ERIC Educational Resources Information Center

    Vaughn, Kathleen Adams

    2012-01-01

    In an effort to close the achievement gap between students of minority and majority populations and between students in higher and lower economic circumstances, the National Council for the Accreditation of Teacher Education (NCATE) added instruction and evaluation of teacher dispositions to its requirements for credentialing prospective teachers.…

  19. Birth weight and academic achievement in childhood.

    PubMed

    Chatterji, Pinka; Kim, Dohyung; Lahiri, Kajal

    2014-09-01

    Research has shown that birth weight has a lasting impact on later-life outcomes such as educational attainment and earnings. This paper examines the role of health at birth in determining academic achievement in childhood, which may provide the link between birth weight and adult outcomes. Using three waves of the Child Development Supplement of the Panel Study of Income Dynamics data over 1997-2007, we build on the literature by employing the fetal growth rate as a proxy for net nutritional intake in utero and propose a nested error-component two-stage least squares estimator that draws on internal instruments from alternative dimensions of the multilevel panel data set. In particular, this alternative estimator allows us to exploit the information on children with no siblings in the sample, which comprise over 40% of the observations in our sample, as well as to obtain coefficient estimates for the time-invariant variables such as race and maternal education. This would not be feasible with the usual mother fixed effects estimation. We obtain modest but significant effects of both birth weight and the fetal growth rate on math and reading scores, with the effects concentrated in the low birth weight range. Infant health measures appear to explain little of the well-documented racial disparity in test scores. PMID:25044537

  20. Journal of Crystal Growth 266 (2004) 552567 Three-dimensional crystal growth--II: nonlinear simulation

    E-print Network

    Lowengrub, John

    2004-01-01

    Journal of Crystal Growth 266 (2004) 552­567 Three-dimensional crystal growth--II: nonlinear previous analysis (J Crystal Growth 240 (2002) 267) of the linear evolution of non-spherical growing to be carried out in a laboratory in which a desired shape of a crystal is achieved and maintained during growth

  1. Optimizing an algebraic perceptron solution

    Microsoft Academic Search

    Thomas Hanselmann; Lyle Noakes

    2001-01-01

    In this paper ways of optimizing a solution achieved by the perceptron algorithm are investigated. The perceptron algorithm was successfully applied to polynomial inner-product kernels equivalent to those of support vector machines (SVM). Therefore, the algebraic perceptron can achieve a polynomial separation in the input data space by doing a linear separation in a high-dimensional feature space. Unlike the solution

  2. Purification, growth, fabrication and characterization of wide bandgap materials. Final technical report

    SciTech Connect

    Chen, K.T.; Chen, H.; Burger, A.

    1998-05-01

    Wide bandgap semiconductor single crystals, such as heavy metal halide compounds, have been grown by physical vapor transport and Bridgman methods. Zone-refining and vacuum sublimation techniques were used to purify and adjust the stoichiometric composition of the starting material, and were proven to be effective. Several spectroscopic, microscopic and thermodynamic analytical techniques were employed to investigate the optical, electrical and structural properties of crystals. These results revealed information regarding micro- and macroscopic defects, impurities and modifications resulting from source material, growth process, post-growth treatment and device fabrication. Crystal growth and processing conditions have been correlated with this information and were optimized to achieve the purest and highest quality materials for practical device applications. Future works will involve optimization of material purification and crystal growth processes to produce high purity and low defect crystals, development of sensitive material characterization tools allowing a better understanding of defects formation and their correlation with processing conditions. Developments in bulk crystal growth research for detector devices in the Center for Photonic Materials and Devices since its establishment have been reviewed. Purification processes and single crystal growth systems employing physical vapor transport and Bridgman methods were assembled and used to produce high purity and superior quality wide bandgap materials based on heavy metal halides semiconductors. Comprehensive material characterization techniques have been employed to reveal the optical, electrical and thermodynamic properties of crystals, and the results were used to establish improved material processing procedures.

  3. Quantitative analysis of compensatory and catch-up growth in diverse taxa.

    PubMed

    Hector, Katie L; Nakagawa, Shinichi

    2012-05-01

    1.?'Compensatory growth' and 'catch-up growth' are often used interchangeably to describe the faster than optimal growth that occurs following a period of dietary restriction in the development of many animals. Concerns about the statistical analysis of these studies have drawn attention to the risk of false detection in reports of compensatory and catch-up growth. 2.?This study aims to quantify the degree to which these compensatory responses occur across the animal kingdom. In addition, this study distinguishes the two terms, 'compensatory growth' and 'catch-up growth', to clarify the fitness consequences of rapid growth. Compensatory growth refers to a faster than usual growth rate, while catch-up growth implies attainment of control size. 3.?Eight meta-analyses and meta-regression analyses were conducted on data extracted from 88 papers, including 11 taxonomic classes. The results confirmed that both growth tactics (i.e. compensatory and catch-up growth) occur across a wide range of taxa and result in decreased direct fitness components. 4.?Importantly, the meta-analytic methods used made it possible to identify the specific experimental techniques that most successfully promoted rapid growth after restriction and key differences in the responses of the four major groups (mammals, birds, fish and arthropods) to dietary restriction. Endotherms are more likely to show a compensatory growth response because of their determinate growth; in contrast, the indeterminate and saltatory growth tactics of fish and arthropods reduce the pressure to rapidly achieve a large size. 5.?Among the first meta-analyses to be conducted in this field, this study provides valuable support for the premises of compensatory and catch-up growth and also discusses weaknesses in experimental design, and possible solutions, in compensatory growth research. For example, we recommend conducting the experiment within the most linear phase of an animal's growth to avoid analytical complications arising from size-dependent growth, and our results indicate that dietary dilution more closely resembles quantitative restriction than clutch size and intermittent feeding restriction methods when normal quantitative restriction is not possible. PMID:22269070

  4. School Readiness and Later Achievement

    Microsoft Academic Search

    Greg J. Duncan; Chantelle J. Dowsett; Amy Claessens; Katherine Magnuson; Aletha C. Huston; Pamela Klebanov; Linda S. Pagani; Leon Feinstein; Mimi Engel; Jeanne Brooks-Gunn; Holly Sexton; Kathryn Duckworth; Crista Japel

    2007-01-01

    Using 6 longitudinal data sets, the authors estimate links between three key elements of school readiness—school-entry academic, attention, and socioemotional skills—and later school reading and math achievement. In an effort to isolate the effects of these school-entry skills, the authors ensured that most of their regression models control for cognitive, attention, and socioemotional skills measured prior to school entry, as

  5. The Effects of Chronic Achievement Motivation and Achievement Primes on the Activation of Achievement and Fun Goals

    Microsoft Academic Search

    William Hart; Dolores Albarracín

    2009-01-01

    This research examined the hypothesis that situational achievement cues can elicit achievement or fun goals depending on chronic differences in achievement motivation. In 4 studies, chronic differences in achievement motivation were measured, and achievement-denoting words were used to influence behavior. The effects of these variables were assessed on self-report inventories, task performance, task resumption following an interruption, and the pursuit

  6. Role of Prism Decussation on Fatigue Crack Growth and Fracture of Human Enamel

    PubMed Central

    Bajaj, Devendra; Arola, Dwayne

    2009-01-01

    The role of prism decussation on the crack growth resistance of human enamel is evaluated. Miniature inset Compact Tension (CT) specimens embodying a section of cuspal enamel were subjected to Mode I cyclic or monotonic loads. Cracks were grown in either the forward (from outer enamel inwards) or reverse (from inner enamel outwards) direction and the responses were compared quantitatively. Results showed that the outer enamel exhibits lower resistance to the inception and growth of cracks. Regardless of the growth direction, the near threshold region of cyclic extension was typical of ‘short crack’ behavior (i.e. deceleration of growth with an increase in crack length). Cyclic crack growth was more stable in the forward direction and occurred over twice the spatial distance achieved in the reverse direction. In response to the monotonic loads, a rising R-curve response was exhibited by growth in the forward direction only. The total energy absorbed in fracture for the forward direction was more than three times that in the reverse. The rise in crack growth resistance was largely attributed to a combination of mechanisms that included crack bridging, crack bifurcation and crack curving, which were induced by decussation in the inner enamel. An analysis of the responses distinguished that the microstructure of enamel appears optimized for resisting crack growth initiating from damage at the tooth’s surface. PMID:19433137

  7. Trajectory Optimization for Unpowered Gliding Submissile

    Microsoft Academic Search

    Shi Jiao; Tang Shengjing; Yang Chun-lei

    2009-01-01

    Longer range and larger impact angle are the requirements of modern anti-armor missiles being studied. In order to achieve this goal, a method for trajectory optimization is introduced by transferring the design of trajectory optimization to solving nonlinear programming problems, and the gliding trajectory as well as the terminal guidance trajectory is optimized. The improved flight model of the unpowered

  8. Optimal fuzzy controller design: local concept approach

    Microsoft Academic Search

    Shinq-Jen Wu; Chin-Teng Lin

    2000-01-01

    In this paper, we present a global optimal and stable fuzzy controller design method for both continuous- and discrete-time fuzzy systems under both finite and infinite horizons. First, a sufficient condition is proposed which indicates that the global optimal effect can be achieved by the fuzzily combined local optimal controllers. Based on this sufficient condition, we derive a local concept

  9. Adaptive Growth Decisions in Butterflies

    NSDL National Science Digital Library

    Karl Gotthard (Stockholm University; )

    2008-03-01

    Caterpillars have a great capacity for rapid weight gain, but to reap the benefits of this capacity, larvae must be able to survive in a hostile environment and emerge as adults at the right time of year. In this article, I review examples of growth decisions in butterfly larvae that can be viewed as adaptations for optimized growth performance. These include sex-specific growth decisions that lead to protandry and sexual size dimorphism, fine-tuning of growth in response to photoperiod and temperature, development of alternative larval morphs that mimic the plant structures they feed on, and the peculiar growth patterns of lycenid butterflies that manipulate ants and grow as cuckoos inside ant nests. I conclude that growth of an individual can be seen as the sum of several environmentally dependent decisions, which may influence the growth trajectory by changes in physiology, behavior, and morphology.

  10. The Optimal Swimming Sheet

    E-print Network

    Montenegro-Johnson, Thomas D

    2014-01-01

    Propulsion at microscopic scales is often achieved through propagating traveling waves along hair-like organelles called flagella. Taylor's two-dimensional swimming sheet model is frequently used to provide insight into problems of flagellar propulsion. We derive numerically the large-amplitude waveform of the two-dimensional swimming sheet that yields optimum hydrodynamic efficiency; the ratio of the squared swimming speed to the rate-of-working of the sheet against the fluid. Using the boundary element method, we show the optimal waveform is a front-back symmetric regularized cusp that is 25% more efficient than the optimal sine-wave. This optimal two-dimensional shape is smooth, qualitatively different from the kinked form of Lighthill's optimal three-dimensional flagellum, not predicted by small-amplitude theory, and different from the smooth circular-arc-like shape of active elastic filaments.

  11. RF Gun Optimization Study

    SciTech Connect

    A. S. Hofler; P. Evtushenko; M. Krasilnikov

    2007-08-01

    Injector gun design is an iterative process where the designer optimizes a few nonlinearly interdependent beam parameters to achieve the required beam quality for a particle accelerator. Few tools exist to automate the optimization process and thoroughly explore the parameter space. The challenging beam requirements of new accelerator applications such as light sources and electron cooling devices drive the development of RF and SRF photo injectors. RF and SRF gun design is further complicated because the bunches are space charge dominated and require additional emittance compensation. A genetic algorithm has been successfully used to optimize DC photo injector designs for Cornell* and Jefferson Lab**, and we propose studying how the genetic algorithm techniques can be applied to the design of RF and SRF gun injectors. In this paper, we report on the initial phase of the study where we model and optimize gun designs that have been benchmarked with beam measurements and simulation.

  12. Crystal Growth Control

    NASA Technical Reports Server (NTRS)

    Duval, Walter M. B.; Batur, Celal; Bennett, Robert J.

    1997-01-01

    We present an innovative design of a vertical transparent multizone furnace which can operate in the temperature range of 25 C to 750 C and deliver thermal gradients of 2 C/cm to 45 C/cm for the commercial applications to crystal growth. The operation of the eight zone furnace is based on a self-tuning temperature control system with a DC power supply for optimal thermal stability. We show that the desired thermal profile over the entire length of the furnace consists of a functional combination of the fundamental thermal profiles for each individual zone obtained by setting the set-point temperature for that zone. The self-tuning system accounts for the zone to zone thermal interactions. The control system operates such that the thermal profile is maintained under thermal load, thus boundary conditions on crystal growth ampoules can be predetermined prior to crystal growth. Temperature profiles for the growth of crystals via directional solidification, vapor transport techniques, and multiple gradient applications are shown to be easily implemented. The unique feature of its transparency and ease of programming thermal profiles make the furnace useful for scientific and commercial applications for the determination of process parameters to optimize crystal growth conditions.

  13. Achievement Motivation as a Function of Assimilation and Differentiation Needs

    Microsoft Academic Search

    DeLeon L. Gray; Kimberly Rios

    2012-01-01

    Building upon Optimal Distinctiveness Theory (Brewer, 1991), we propose that students will exhibit increased self-regulatory persistence and performance to satisfy their needs for assimilation and differentiation. In Study 1, undergraduates rated the importance of 16 achievement-related tasks (e.g., studying for examinations, class participation). A within-persons hierarchical linear model revealed that the more students perceived enacting these behaviors as satisfying their

  14. Achieving MAC layer fairness in wireless packet networks

    Microsoft Academic Search

    Thyagarajan Nandagopal; Tae-Eun Kim; Xia Gao; Vaduvur Bharghavan

    2000-01-01

    Link-layer fairness models that have been proposed for wireline and packet cellular networks cannot be generalized for shared channel wireless networks because of the unique characteristics of the wireless channel, such as location-dependent contention, inherent conflict between optimizing channel utilization and achieving fairness, and the absence of any centralized control.In this paper, we propose a general analytical framework that captures

  15. Achieving true sustainability of zoo populations.

    PubMed

    Lacy, Robert C

    2013-01-01

    For the last 30 years, cooperative management of irreplaceable animal populations in zoos and aquariums has focused primarily on the goal of minimizing genetic decay within defined time frames, and large advances have been made in technologies to optimize genetic management of closed populations. However, recent analyses have shown that most zoo programs are not projected to meet their stated goals. This has been described as a lack of achieving "sustainability" of the populations, yet by definition a goal of managed decay is not a plan for sustainability. True sustainability requires management of the resource in manner that does not deplete its value for the future. Achieving such sustainability for many managed populations may require changing from managing isolated populations to managing populations that are part of a broader metapopulation, with carefully considered exchange between populations across a spectrum of ex situ to in situ. Managing zoo populations as components of comprehensive conservation strategies for the species will require research on determinants of various kinds of genetic, physiological, behavioral, and morphological variation and their roles in population viability, development of an array of management techniques and tools, training of population managers in metapopulation management and integrated conservation planning, and projections of impacts of management strategies on the viability of the captive populations and all populations that are interactively managed or affected. Such a shift in goals and methods would result in zoo population management being an ongoing part of species conservation rather than short-term or isolated from species conservation. Zoo Biol. 32:19-26, 2013. © 2012 Wiley Periodicals, Inc. PMID:22753040

  16. Centre for Academic Achievement `Aiming High'

    E-print Network

    Humphrys, Mark

    Centre for Academic Achievement `Aiming High' Background The Centre for Academic Achievement (CAA Somewhat dissatisfied Very Dissatisfied %ofparents March May Achievements The Centre for Academic teachers involved. There were major academic benefits for the students participating including an increase

  17. Achieving permanency for LGBTQ youth.

    PubMed

    Jacobs, Jill; Freundlich, Madelyn

    2006-01-01

    This article brings together two significant efforts in the child welfare field: achieving permanence for youth in out-of-home care and meeting the needs of lesbian, gay, bisexual, transgender and questioning (LGBTQ) youth. During the past several years, a national movement has taken place to assure all children and youth have a permanent family connection before leaving the child welfare system; however, LGBTQ youth are not routinely included in the permanency discussions. At the same time, efforts in addressing the needs of LGBTQ youth have increased, but permanency is rarely mentioned as a need. This article offers models of permanence and practices to facilitate permanence with LGBTQ youth and their families. It also offers a youth-driven, individualized process, using youth development principles to achieve relational, physical, and legal permanence. Reunification efforts are discussed, including services, supports, and education required for youth to return to their family of origin. For those who cannot return home, other family resources are explored. The article also discusses cultural issues as they affect permanence for LGBTQ youth, and, finally, addresses the need for ongoing support services to sustain and support permanency. PMID:16846117

  18. The Effects of Chronic Achievement Motivation and Achievement Primes on the Activation of Achievement and Fun Goals

    PubMed Central

    Hart, William; Albarracín, Dolores

    2013-01-01

    This research examined the hypothesis that situational achievement cues can elicit achievement or fun goals depending on chronic differences in achievement motivation. In 4 studies, chronic differences in achievement motivation were measured, and achievement-denoting words were used to influence behavior. The effects of these variables were assessed on self-report inventories, task performance, task resumption following an interruption, and the pursuit of means relevant to achieving or having fun. Findings indicated that achievement priming (vs. control priming) activated a goal to achieve and inhibited a goal to have fun in individuals with chronically high-achievement motivation but activated a goal to have fun and inhibited a goal to achieve in individuals with chronically low-achievement motivation. PMID:19968423

  19. Polite Water-filling for the Boundary of the Capacity/Achievable Regions of MIMO

    E-print Network

    Liu, Youjian "Eugene"

    Polite Water-filling for the Boundary of the Capacity/Achievable Regions of MIMO MAC of water-filling that is optimal for all boundary points of the capac- ity regions of MIMO multiaccess polite water-filling, that is optimal for all boundary points of the capacity regions of MAC and BC

  20. Development of the vertical Bridgman technique for 6-inch diameter c-axis sapphire growth supported by numerical simulation

    NASA Astrophysics Data System (ADS)

    Miyagawa, Chihiro; Kobayashi, Takumi; Taishi, Toshinori; Hoshikawa, Keigo

    2014-09-01

    Based on the growth of 3-inch diameter c-axis sapphire using the vertical Bridgman (VB) technique, numerical simulations were made and used to guide the growth of a 6-inch diameter sapphire. A 2D model of the VB hot-zone was constructed, the seeding interface shape of the 3-inch diameter sapphire as revealed by green laser scattering was estimated numerically, and the temperature distributions of two VB hot-zone models designed for 6-inch diameter sapphire growth were numerically simulated to achieve the optimal growth of large crystals. The hot-zone model with one heater was selected and prepared, and 6-inch diameter c-axis sapphire boules were actually grown, as predicted by the numerical results.

  1. Effect of calcium, phosphate and nitrogen on cell growth and biosynthesis of cell wall polysaccharides by Silene vulgaris cell culture.

    PubMed

    Günter, Elena A; Ovodov, Yury S

    2005-06-29

    Medium nutrients such as calcium, phosphorus, nitrogen and nitrate to ammonium ratio have significant influence on the growth, biosynthetic and biochemical characteristics of polysaccharides produced by Silene vulgaris (M.) G. cell culture. Cell growth and production of polysaccharides was limited by an absence of any of these components in the medium. Optimal growth of the callus and production of arabinogalactan were achieved at 1.5-4.5 microM calcium while the optimal production of pectin named silenan was observed at 3.0-4.5 microM. The phosphate contents in the medium in the range of 0.63-3.75 microM were favorable for callus growth. Production of silenan was maximal at 1.25-3.75 microM phosphate. Optimal growth of the callus was achieved at 30-90 microM nitrogen. Maximal production of silenan was observed at 60 microM nitrogen while the optimal production of arabinogalactan was at 90 microM nitrogen (at ratio of NH(4)(+):NO(3)(-) as 1:2). A presence both of nitrate and ammonium is needed for the silenan biosynthesis (the NH(4)(+):NO(3)(-) ratio as 1:1 and 1:2). Yields and volumetric production of arabinogalactan were maximal at deletion of ammonium from the nutrient medium (ratio 0:1). Absence of calcium or nitrogen in the medium leads to a decrease of the galacturonic acid residues in silenan. The galactose residues contents in arabinogalactan were decreased in the absence of nitrogen and calcium in the medium. PMID:15878212

  2. Rapid optimization of drug combinations for the optimal angiostatic treatment of cancer.

    PubMed

    Weiss, Andrea; Ding, Xianting; van Beijnum, Judy R; Wong, Ieong; Wong, Tse J; Berndsen, Robert H; Dormond, Olivier; Dallinga, Marchien; Shen, Li; Schlingemann, Reinier O; Pili, Roberto; Ho, Chih-Ming; Dyson, Paul J; van den Bergh, Hubert; Griffioen, Arjan W; Nowak-Sliwinska, Patrycja

    2015-07-01

    Drug combinations can improve angiostatic cancer treatment efficacy and enable the reduction of side effects and drug resistance. Combining drugs is non-trivial due to the high number of possibilities. We applied a feedback system control (FSC) technique with a population-based stochastic search algorithm to navigate through the large parametric space of nine angiostatic drugs at four concentrations to identify optimal low-dose drug combinations. This implied an iterative approach of in vitro testing of endothelial cell viability and algorithm-based analysis. The optimal synergistic drug combination, containing erlotinib, BEZ-235 and RAPTA-C, was reached in a small number of iterations. Final drug combinations showed enhanced endothelial cell specificity and synergistically inhibited proliferation (p < 0.001), but not migration of endothelial cells, and forced enhanced numbers of endothelial cells to undergo apoptosis (p < 0.01). Successful translation of this drug combination was achieved in two preclinical in vivo tumor models. Tumor growth was inhibited synergistically and significantly (p < 0.05 and p < 0.01, respectively) using reduced drug doses as compared to optimal single-drug concentrations. At the applied conditions, single-drug monotherapies had no or negligible activity in these models. We suggest that FSC can be used for rapid identification of effective, reduced dose, multi-drug combinations for the treatment of cancer and other diseases. PMID:25824484

  3. A Low-Complexity Near-ML Performance Achieving Algorithm for Large MIMO Detection

    E-print Network

    Kumar, Anurag

    per- bit complexity linear in number of users, while achieving near-optimal performance in largeA Low-Complexity Near-ML Performance Achieving Algorithm for Large MIMO Detection Saif K. Mohammed 560012, INDIA Abstract--In this paper, we present a low-complexity, near maxi- mum-likelihood (ML

  4. How Group Composition Influenced the Achievement of Sixth-Grade Mathematics Students.

    ERIC Educational Resources Information Center

    Leonard, Jacqueline

    2001-01-01

    Reports on the achievement of 177 sixth grade mathematics students who were studied over two consecutive years. The purpose of the study was to determine whether learning and achievement were optimal in heterogeneous or homogeneous ability groups. Results show a significant difference between posttest scores of the 1995-1996 heterogeneous cohort…

  5. Using Correlational and Prediction Data to Enhance Student Achievement in K-12 Schools: A Practical Application for School Counselors

    ERIC Educational Resources Information Center

    Ware, William B.; Galassi, John P.

    2006-01-01

    Correlational data and regression analysis provide the school counselor with a method to describe growth in achievement test scores from elementary to high school. Using Microsoft Excel, this article shows the reader in a step-by-step manner how to describe this growth pattern and how to evaluate interventions that attempt to enhance achievement

  6. Selecting and Using Plant Growth Regulators on Floricultural Crops

    E-print Network

    Liskiewicz, Maciej

    #12;Selecting and Using Plant Growth Regulators on Floricultural Crops Joyce Latimer, Extension Specialist, Greenhouse Crops, Virginia Tech Brian Whipker, Extension Specialist, Floriculture Crops, North Carolina State University #12;Selecting and Using Plant Growth Regulators on Floricultural Crops Optimizing

  7. Achieving Quality in Occupational Health

    NASA Technical Reports Server (NTRS)

    O'Donnell, Michele (Editor); Hoffler, G. Wyckliffe (Editor)

    1997-01-01

    The conference convened approximately 100 registered participants of invited guest speakers, NASA presenters, and a broad spectrum of the Occupational Health disciplines representing NASA Headquarters and all NASA Field Centers. Centered on the theme, "Achieving Quality in Occupational Health," conferees heard presentations from award winning occupational health program professionals within the Agency and from private industry; updates on ISO 9000 status, quality assurance, and information technologies; workshops on ergonomics and respiratory protection; an overview from the newly commissioned NASA Occupational Health Assessment Team; and a keynote speech on improving women's health. In addition, NASA occupational health specialists presented 24 poster sessions and oral deliveries on various aspects of current practice at their field centers.

  8. Achieving the Benefits of Safeguards by Design

    SciTech Connect

    Trond Bjornard; Robert Bean; David Hebditch; Jim Morgan; Bruce Meppen; Scott DeMuth; Michael Ehinger; John Hockert

    2008-07-01

    The overarching driver for developing a formalized process to achieve safeguards by design is to support the global growth of nuclear power while reducing ‘nuclear security’ risks. This paper discusses an institutional approach to the design process for a nuclear facility, for designing proliferation resistance, international safeguards and U.S. national safeguards and security into new nuclear facilities. In the United States, the need exists to develop a simple, concise, formalized, and integrated approach for incorporating international safeguards and other non-proliferation considerations into the facility design process. An effective and efficient design process is one which clearly defines the functional requirements at the beginning of the project and provides for the execution of the project to achieve a reasonable balance among competing objectives in a cost effective manner. Safeguards by Design is defined as “the integration of international and national safeguards, physical security and non-proliferation features as full and equal partners in the design process of a nuclear energy system or facility,” with the objective to achieve facilities that are intrinsically more robust while being less expensive to safeguard and protect. This Safeguards by Design process has been developed such that it: • Provides improved safeguards, security, and stronger proliferation barriers, while reducing the life cycle costs to the operator and regulatory agencies, • Can be translated to any international context as a model for nuclear facility design, • Fosters a culture change to ensure the treatment of ‘nuclear security’ considerations as “full and equal” partners in the design process, • Provides a useful tool for the project manager responsible for the design, construction, and start-up of nuclear facilities, and • Addresses the key integration activities necessary to efficiently incorporate International Atomic Energy Agency safeguards into the design of nuclear facilities. This paper describes the work that has been completed in the development of a Safeguards by Design process for a project, illustrated by flow diagrams based upon the project phases described in U.S. Department of Energy Order 413.3A, Program and Project Management for the Acquisition of Capital Assets. The institutionalization of the Safeguards by Design process directly supports the goals of the Next Generation Safeguards Initiative and also aligns with goals and objectives of the International Atomic Energy Agency. Other benefits from institutionalizing this Safeguards by Design process are discussed within this paper.

  9. Autocrine Hepatocyte Growth Factor Provides a Local Mechanism for Promoting Axonal Growth

    Microsoft Academic Search

    Xiu-Ming Yang; Jean G. Toma; Shernaz X. Bamji; Daniel J. Belliveau; Judi Kohn; Morag Park; Freda D. Miller

    1998-01-01

    In this report, we describe a novel local mechanism necessary for optimal axonal growth that involves hepatocyte growth factor (HGF). Sympathetic neurons of the superior cervical ganglion coexpress bioactive HGF and its receptor, the Met tyrosine kinase, both in vivo and in vitro. Exogenous HGF selectively promotes the growth but not survival of cultured sympathetic neurons; the magnitude of this

  10. Toward integrated strategies for achieving environmental quality

    SciTech Connect

    Kuusinen, T.; Lesperance, A.; Bilyard, G. (Pacific Northwest Lab., Richland, WA (United States))

    1994-03-01

    In the United States, environmentalists are constantly jumping from one environmental crisis of the day'' to another without any sense of what is important and what is trivial. Moreover, when designing fixes to the environmental problems one tries to resolve, one often comes up short. This country urgently needs a national environmental strategy that will approach environmental issues proactively and logically. Without such a strategy, the authors believe that long-term, sustainable economic growth cannot be achieved in the United States. This paper outlines a participatory process by which the framework for a national environmental strategy might be developed. It also proposes that such a strategy will likely include two fundamental components: (1) consensus principles for conducting risk assessments to decide what environmental problems are most important, and (2) a generalized, market-oriented model for resolving these problems. A viable national consensus will be required for such a strategy to succeed and will need to include industry, labor, legislators, regulators, national environmental advocacy groups, local grass roots organizations, and other interested parties.

  11. Medical Biotechnology Trends and Achievements in Iran

    PubMed Central

    Mahboudi, Fereidoun; Hamedifar, Haleh; Aghajani, Hamideh

    2012-01-01

    A healthcare system has been the most important priority for all governments worldwide. Biotechnology products have affected the promotion of health care over the last thirty years. During the last several decades, Iran has achieved significant success in extending healthcare to the rural areas and in reducing the rates of infant mortality and increasing population growth. Biomedical technology as a converging technology is considered a helpful tool to fulfill the Iranian healthcare missions. The number of biotechnology products has reached 148 in 2012. The total sales have increased to 98 billion USD without considering vaccines and plasma derived proteins in 2012. Iran is one of the leading countries in the Middle East and North Africa in the area of Medical biotechnology. The number of biotechnology medicines launched in Iran is 13 products until 2012. More than 15 products are in pipelines now. Manufacturers are expecting to receive the market release for more than 8 products by the end of 2012. Considering this information, Iran will lead the biotechnology products especially in area of biosimilars in Asia after India in next three years. The present review will discuss leading policy, decision makers’ role, human resource developing system and industry development in medical biotechnology. PMID:23407888

  12. Enhanced thermal conductivity of polycrystalline aluminum nitride thin films by optimizing the interface structure

    SciTech Connect

    Pan, T. S.; Zhang, Y.; Huang, J.; Zeng, B.; Hong, D. H.; Zeng, H. Z.; Gao, M.; Huang, W.; Lin, Y. [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Wang, S. L. [Analytical and Testing Center, Sichuan University, Chengdu 610065 (China)

    2012-08-15

    The growth-temperature dependency and interface structure effects on the thermal conductivity of the highly textured AlN thin films on (001) Si substrates were systematically studied by characterizing the crystal structures, surface morphologies, interface structures, chemical compositions, and thermal conductivity using x-ray diffraction analysis, atomic force microscopy, high resolution transmission electron microscopy, x-ray photoelectron spectroscopy, and 3-omega method, respectively. By optimizing the interface microstructure and the growth temperature, thermal conductivity of polycrystalline AlN thin films can be greatly enhanced from 9.9 to 26.7 W/mK, when the growth temperature increases from 330 to 560 Degree-Sign C. This achievement is considered to be associated with the diminishment of the amorphous and disordered layer at the AlN/Si interface.

  13. Optimal Pitch, Speed and Fuel Control at Sea Thomas Hellstrom

    E-print Network

    Hellström, Thomas

    fuel oil per day. The saving is achieved by optimizing control at three levels: 1. Pitch optimizationOptimal Pitch, Speed and Fuel Control at Sea Thomas Hellstr¨om Associate Professor, Department of Computing Science, Ume°a University, Sweden. email: thomash@cs.umu.se Keywords: Fuel optimization, Pitch

  14. Relationships among Four Measures of Achievement Motivation

    ERIC Educational Resources Information Center

    Wotruba, Thomas R.; Price, Karl F.

    1975-01-01

    Two new paper-and-pencil tests of achievement motivation were compared to two older measures, McClelland's Thematic Apperception Test (TAT) Need Achievement and the Edwards Personal Preference Schedule achievement scale. The results lend support to past findings; namely, that the various achievement measures would appear to be measuring dissimilar…

  15. Affiliation Motivation and Hawaiian-American Achievement

    ERIC Educational Resources Information Center

    Gallimore, Ronald

    1974-01-01

    Fantasy "n" affiliation (nAff) was correlated with reading achievement test scores, but not math achievement test scores, for a sample of 67 Hawaiian-American high school students. There was no relationship between "n" Ach and achievement test scores. The process linking "n" Aff and Hawaiian American achievement was suggested to involve…

  16. Simultaneous optimization of controlled structures

    NASA Astrophysics Data System (ADS)

    Salama, M.; Garba, J.; Demsetz, L.; Udwadia, F.

    1988-07-01

    A formulation is presented for finding the combined optimal design of a structural system and its control by defining a composite objective function as a linear combination of two components; a structural objective and a control objective. When the structural objective is a function of the structural design variables only, and when the control objective is represented by the quadratic functional of the response and control energy, it is possible to analytically express the optimal control in terms of any set of “admissible” structural design variables. Such expression for the optimal control is used recursively in an iterative Newton-Raphson search scheme, the goal of which is to determine the corresponding optimal set of structural design variables that minimize the combined objective function. A numerical example is given to illustrate the computational procedure. The results indicate that significant improvement of the combined optimal design can be achieved over the traditional separate optimization.

  17. Reduced burst speed is a cost of rapid growth in anuran tadpoles: problems of autocorrelation and inferences about growth rates

    Microsoft Academic Search

    J. D. Arendt

    2003-01-01

    Summary 1. It is becoming clear that individual growth rates are optimized to suit local condi- tions rather than maximized to be as fast as possible. To understand this adaptive variation in growth rates, we need to understand the costs of rapid growth. 2. Recent work in teleost fish suggests that a trade-off between growth rate and critical swimming speed

  18. Achievement Motivation as a Case of Re-Socialization in Developing Countries.

    ERIC Educational Resources Information Center

    Ghosh, Ratna

    The question of achievement motivation in relation to developing countries is explored. A foundation for the study is achieved through discussion of the socialization processes as they are affected by education and economic growth. It is suggested that the societal system determines motivation and values which in turn cause and determine the…

  19. Academic Achievement Trajectories of Adolescents from Mexican and East Asian Immigrant Families in the United States

    ERIC Educational Resources Information Center

    Jeong, Yu-Jin; Acock, Alan C.

    2014-01-01

    Drawing on the National Educational Longitudinal Survey 1988 (NELS:88), this study identified (1) the growth pattern of academic achievement of adolescent children from Mexican and East Asian immigrant families; (2) investigated to what extent ethnicity and family capital influenced the trajectories in the academic achievement of children from…

  20. The Forms of Capital and the Developed Achievement of Black Males

    ERIC Educational Resources Information Center

    Dixon-Román, Ezekiel J.

    2013-01-01

    This study sought to examine the association of the various forms of capital on the developed achievement of Black males. As one of the richest longitudinal family economic data sets, the Child Development Supplement to the Panel Study of Income Dynamics is used to estimate multilevel growth models of the math and reading achievement of Black…

  1. Thermoacoustic Refrigerator's Stack Optimization

    NASA Astrophysics Data System (ADS)

    El-Fawal, Mawahib Hassan; Mohd-Ghazali, Normah; Yaacob, Mohd. Shafik; Darus, Amer Nordin

    2010-06-01

    The standing wave thermoacoustic refrigerator, which uses sound generation to transfer heat, was developed rapidly during the past four decades. It was regarded as a new, promising and environmentally benign alternative to conventional compression vapor refrigerators, although it was not competitive regarding the coefficient of performance (COP) yet. Thus the aim of this paper is to enhance thermoacoustic refrigerator's stack performance through optimization. A computational optimization procedure of thermoacoustic stack design was fully developed. The procedure was designed to achieve optimal coefficient of performance based on most of the design and operating parameters. Cooling load and acoustic power governing equations were set assuming the linear thermoacoustic theory. Lagrange multipliers method was used as an optimization technique tool to solve the governing equations. Numerical analyses results of the developed design procedure are presented. The results showed that the stack design parameters are the most significant parameters for the optimal overall performance. The coefficient of performance obtained increases by about 48.8% from the published experimental optimization methods. The results are in good agreement with past established studies.

  2. Competency-Based Achievement System

    PubMed Central

    Ross, Shelley; Poth, Cheryl N.; Donoff, Michel; Humphries, Paul; Steiner, Ivan; Schipper, Shirley; Janke, Fred; Nichols, Darren

    2011-01-01

    Abstract Problem addressed Family medicine residency programs require innovative means to assess residents’ competence in “soft” skills (eg, patient-centred care, communication, and professionalism) and to identify residents who are having difficulty early enough in their residency to provide remedial training. Objective of program To develop a method to assess residents’ competence in various skills and to identify residents who are having difficulty. Program description The Competency-Based Achievement System (CBAS) was designed to measure competence using 3 main principles: formative feedback, guided self-assessment, and regular face-to-face meetings. The CBAS is resident driven and provides a framework for meaningful interactions between residents and advisors. Residents use the CBAS to organize and review their feedback, to guide their own assessment of their progress, and to discern their future learning needs. Advisors use the CBAS to monitor, guide, and verify residents’ knowledge of and competence in important skills. Conclusion By focusing on specific skills and behaviour, the CBAS enables residents and advisors to make formative assessments and to communicate their findings. Feedback indicates that the CBAS is a user-friendly and helpful system to assess competence. PMID:21918129

  3. Biodiesel surrogates: achieving performance demands.

    PubMed

    Sarin, Rakesh; Kumar, Ravindra; Srivastav, Bhawana; Puri, S K; Tuli, D K; Malhotra, R K; Kumar, Anand

    2009-06-01

    Synthesis of surrogate molecules is particularly useful for generating in sight of structural-activity relationships, understanding processes and improving the performance. In order to improve upon the physico-chemical properties of biodiesel, methyl, ethyl, isopropyl and n-butyl esters of beta-branched fatty acid have been synthesized, initiating from beta-branched alcohols. Beta-branched alcohols upon oxidation gave corresponding acids, which were converted to their esters. The synthesized esters have substantially better oxidative stability, exhibited by Rancimat oxidation induction period of more than 24 h. The cloud point of synthesized esters is < -36 degrees C, pour point is < -42 degrees C and CFPP is < -21 degrees C, which is substantially better than fatty acid methyl esters. Besides achieving the objective of better oxidative stability and improved low temperature properties, the synthesized surrogate esters have viscosity in the range of 4.2-4.6 cSt at 40 degrees C, meeting the international diesel and biodiesel standards. The cetane number of synthesized esters is 62-69, which is much better than diesel and biodiesel. The blends of the synthesized esters in diesel at 5% and 10% meet Indian standards of diesel. PMID:19243934

  4. Academic Achievement Among Juvenile Detainees.

    PubMed

    Grigorenko, Elena L; Macomber, Donna; Hart, Lesley; Naples, Adam; Chapman, John; Geib, Catherine F; Chart, Hilary; Tan, Mei; Wolhendler, Baruch; Wagner, Richard

    2015-07-01

    The literature has long pointed to heightened frequencies of learning disabilities (LD) within the population of law offenders; however, a systematic appraisal of these observations, careful estimation of these frequencies, and investigation of their correlates and causes have been lacking. Here we present data collected from all youth (1,337 unique admissions, mean age 14.81, 20.3% females) placed in detention in Connecticut (January 1, 2010-July 1, 2011). All youth completed a computerized educational screener designed to test a range of performance in reading (word and text levels) and mathematics. A subsample (n = 410) received the Wide Range Achievement Test, in addition to the educational screener. Quantitative (scale-based) and qualitative (grade-equivalence-based) indicators were then analyzed for both assessments. Results established the range of LD in this sample from 13% to 40%, averaging 24.9%. This work provides a systematic exploration of the type and severity of word and text reading and mathematics skill deficiencies among juvenile detainees and builds the foundation for subsequent efforts that may link these deficiencies to both more formal, structured, and variable definitions and classifications of LD, and to other types of disabilities (e.g., intellectual disability) and developmental disorders (e.g., ADHD) that need to be conducted in future research. PMID:24064502

  5. Prasugrel development - claims and achievements.

    PubMed

    Serebruany, Victor; Shalito, Inna; Kopyleva, Olga

    2009-01-01

    The priority task to develop better and safer antiplatelet agents is difficult to overestimate. In fact, oral antiplatelet agents, such as aspirin in ISIS-2 study, and clopidogrel in COMMIT mega trial in moderate doses are among the very few classes of drugs, which lead to the absolute mortality reduction benefit in patients after acute vascular thrombotic events. Prasugrel is an experimental thienopyridine, and irreversible antagonist of ADP P2Y(12) receptor leading to inhibition of platelet activation and aggregation. The recent TRITON trial, assessing head-to-head prasugrel versus standard of care clopidogrel, both on top of aspirin, reveals numerous controversies with regard to the trial design, definition of events, interpretation of the results, and suitability of the high maintenance prasugrel dose for chronic preventive human use. We critically review various aspects of prasugrel development, focusing on the discrepancies between claims and achievements. We conclude that the benefits of prasugrel are overestimated, and the risks, especially during chronic use are underestimated. Very careful maintenance-dose selection with the main focus on long-term safety profile for the new agents will become a key to success for the future oral antiplatelet drug development. PMID:19132184

  6. CIAS: achieving interoperability using CORBA

    NASA Astrophysics Data System (ADS)

    Moreno, Ramon A.; Fiales, Vivian R.; Furuie, Sergio S.

    2002-05-01

    This paper presents one of the efforts of the Heart Institute of Sao Paulo for the development of a distributed system for retrieving and research of medical images and medical information. The objective is the implementation of an open architecture based on the Clinical Image Access Service (CIAS) specification, defined by Object Management Group, which allows the recover of meta-data and relevant information for general practitioners and clinical specialists in a multi-platform, distributed environment. The CIAS-InCor was developed in Java language, to achieve multi-platform capability, together with CORBA. The images are received in DICOM format, being stored into relational database for the recover of meta-information through the CIAS specification. A prototype of a CIAS server and client were designed and implemented. It has been possible to recover images and clinical information from the CIAS server in a distributed, non-homogenous environment with success. Through the use of standards and new technologies the Heart Institute of Sao Paulo is reaching a high level of integration between systems and equipments and going towards the development of a complete electronic medical record. The CIAS is still an unfinished specification with good points like interoperability and weaknesses like the lack of semantics between exchanged data.

  7. Optimal Implementation of Intervention Strategies for Elderly People with Ludomania

    PubMed Central

    Kim, Byul Nim; Masud, M.A.; Kim, Yongkuk

    2014-01-01

    Objectives Now-a-days gambling is growing especially fast among older adults. To control the gratuitous growth of gambling, well-analyzed scientific strategies are necessary. We tried to analyze the adequacy of the health of society mathematically through immediate treatment of patients with early prevention. Methods The model from Lee and Do was modified and control parameters were introduced. Pontryagin's Maximum Principle was used to obtain an optimal control strategy. Results Optimal control can be achieved through simultaneous use of the control parameters, though it varies from society to society. The control corresponding to prevention needed to be implemented in full almost all the time for all types of societies. In the case of the other two controls, the scenario was greatly affected depending on the types of societies. Conclusion Prevention and treatment for elderly people with ludomania are the main intervention strategies. We found that optimal timely implementation of the intervention strategies was more effective. The optimal control strategy varied with the initial number of gamblers. However, three intervention strategies were considered, among which, preventing people from engaging in all types of gambling proved to be the most crucial. PMID:25389512

  8. Growth Hormone Receptor in Growth

    Microsoft Academic Search

    Vivian Hwa

    \\u000a It has been approximately 20 years since the cloning and characterization of the human growth hormone (GH) receptor, GHR, gene. Cell-surface GHR binds circulating GH, which promotes postnatal growth by regulating the expression of insulin-like\\u000a growth factor (IGF)-I. Mutations in the GHR gene cause GH insensitivity (GHI) syndrome, also known as Laron syndrome, a syndrome characterized by severe postnatal growth

  9. Optimal quantum cloning via spin networks

    SciTech Connect

    Chen Qing [Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China); Cheng Jianhua; Wang Kelin [Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China); Du Jiangfeng [Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China); Fachbereich Physik, Universitaet Dortmund, 44221 Dortmund (Germany)

    2006-09-15

    In this paper we demonstrate that optimal 1{yields}M phase-covariant cloning quantum cloning is available via free dynamical evolution of spin networks. By properly designing the network and the couplings between spins, we show that optimal 1{yields}M phase-covariant cloning can be achieved if the initial state is prepared as a specific symmetric state. Especially, when M is an odd number, the optimal phase-covariant cloning can be achieved without ancillas. Moreover, we demonstrate that the same framework is capable for optimal 1{yields}2 universal cloning.

  10. Effect of Growth Interruption on Surface Recombination Velocity in GaInAsSb/AlGaAsSb Heterostructures Grown by Organometallic Vapor Phase Epitaxy

    SciTech Connect

    CA Wang; DA Shiau; D Donetsky; S Anikeev; G Belenky; S Luryi

    2004-04-29

    The effects of growth interruption on the quality of GaInAsSb/AlGaAsSb heterostructures grown by organometallic vapor phase epitaxy are reported. In-situ reflectance monitoring and ex-situ characterization by high-resolution x-ray diffraction, 4K photoluminescence (PL), and time-resolved PL indicate that GaInAsSb is extremely sensitive to growth interruption time as well as the ambient atmosphere during interruption. By optimizing the interruption sequence, surface recombination velocity as low as 20 cm/s was achieved for GaInAsSb/AlGaAsSb double heterostructures.

  11. State Growth Models for School Accountability: Progress on Development and Reporting Measures of Student Growth

    ERIC Educational Resources Information Center

    Blank, Rolf K.

    2010-01-01

    The Council of Chief State School Officers (CCSSO) is working to respond to increased interest in the use of growth models for school accountability. Growth models are based on tracking change in individual student achievement scores over multiple years. While growth models have been used for decades in academic research and program evaluation, a…

  12. Recombinant collagen production optimization in Escherichia coli

    E-print Network

    Whittemore, Brett A

    2005-01-01

    An Escherichia coli-based collagen-production process was used to investigate several process optimization objectives for use at the industrial scale. The effect of cooling on fermentation growth kinetics was studied, with ...

  13. Combining Genotype Improvement and Statistical Media Optimization for Isoprenoid Production in E. coli

    PubMed Central

    Zhang, Congqiang; Chen, Xixian; Zou, Ruiyang; Zhou, Kang; Stephanopoulos, Gregory; Too, Heng-Phon

    2013-01-01

    Isoprenoids are a large and diverse class of compounds that includes many high value natural products and are thus in great demand. To meet the increasing demand for isoprenoid compounds, metabolic engineering of microbes has been used to produce isoprenoids in an economical and sustainable manner. To achieve high isoprenoid yields using this technology, the availability of metabolic precursors feeding the deoxyxylulose phosphate (DXP) pathway, responsible for isoprenoid biosynthesis, has to be optimized. In this study, phosphoenolpyruvate, a vital DXP pathway precursor, was enriched by deleting the genes encoding the carbohydrate phosphotransferase system (PTS) in E. coli. Production of lycopene (a C40 isoprenoid) was maximized by optimizing growth medium and culture conditions. In optimized conditions, the lycopene yield from PTS mutant was seven fold higher than that obtained from the wild type strain. This resulted in the highest reported specific yield of lycopene produced from the DXP pathway in E. coli to date (20,000 µg/g dry cell weight). Both the copy number of the plasmid encoding the lycopene biosynthetic genes and the expression were found to be increased in the optimized media. Deletion of PTS together with a similar optimization strategy was also successful in enhancing the production of amorpha-1,4-diene, a distinct C15 isoprenoid, suggesting that the approaches developed herein can be generally applied to optimize production of other isoprenoids. PMID:24124471

  14. [Assessment of rice achievable productivity and its application in rice production management division: a case study in Fuyang County of Zhejiang Province, East China].

    PubMed

    Wu, Hao-Xiang; Jiang, Yu-Gen; Chen, Jian-Ming; Dai, Yong-Yi; He, Xu-Hua; Qiu, Xi-Ya

    2011-11-01

    Rice productivity is the key factor affecting rice production and its sustainable development. Based on the gradation of cultivated land quality at county-level, this paper evaluated the rice productivity in Fuyang County of Zhejiang Province, and, through selected sampling field investigation and according to the land productivity index of paddy field quality, a model for assessing rice achievable productivity was established, aimed to analyze the regional rice productivity and its achievable productivity. In the study area, there was a positive correlation between the land productivity index and rice yield. For single cropping rice, its achievable productivity was 1.70 x 10(5) t, being 1.6 times of its realistic productivity (1.04 x 10(5) t). In 2009, the realistic rice productivity per unit area was 7676 kg x hm(-2), and the achievable productivity was 8831 kg x hm(-2), with a production potentiality of +15%, a big potential of rice production capacity in the county. Through the analyses of rice productivity, relative superiority of rice production scale, and its growth potential index in the villages and towns, the rice production of Fuyang County was divided into three regions, i. e., key enhancement region, optimization construction region, and development protection region. PMID:22303662

  15. Metabolism at Evolutionary Optimal States

    PubMed Central

    Rabbers, Iraes; van Heerden, Johan H.; Nordholt, Niclas; Bachmann, Herwig; Teusink, Bas; Bruggeman, Frank J.

    2015-01-01

    Metabolism is generally required for cellular maintenance and for the generation of offspring under conditions that support growth. The rates, yields (efficiencies), adaptation time and robustness of metabolism are therefore key determinants of cellular fitness. For biotechnological applications and our understanding of the evolution of metabolism, it is necessary to figure out how the functional system properties of metabolism can be optimized, via adjustments of the kinetics and expression of enzymes, and by rewiring metabolism. The trade-offs that can occur during such optimizations then indicate fundamental limits to evolutionary innovations and bioengineering. In this paper, we review several theoretical and experimental findings about mechanisms for metabolic optimization. PMID:26042723

  16. Metabolism at evolutionary optimal States.

    PubMed

    Rabbers, Iraes; van Heerden, Johan H; Nordholt, Niclas; Bachmann, Herwig; Teusink, Bas; Bruggeman, Frank J

    2015-01-01

    Metabolism is generally required for cellular maintenance and for the generation of offspring under conditions that support growth. The rates, yields (efficiencies), adaptation time and robustness of metabolism are therefore key determinants of cellular fitness. For biotechnological applications and our understanding of the evolution of metabolism, it is necessary to figure out how the functional system properties of metabolism can be optimized, via adjustments of the kinetics and expression of enzymes, and by rewiring metabolism. The trade-offs that can occur during such optimizations then indicate fundamental limits to evolutionary innovations and bioengineering. In this paper, we review several theoretical and experimental findings about mechanisms for metabolic optimization. PMID:26042723

  17. Source optimization using particle swarm optimization algorithm in photolithography

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Li, Sikun; Wang, Xiangzhao; Yan, Guanyong; Yang, Chaoxing

    2015-03-01

    In recent years, with the availability of freeform sources, source optimization has emerged as one of the key techniques for achieving higher resolution without increasing the complexity of mask design. In this paper, an efficient source optimization approach using particle swarm optimization algorithm is proposed. The sources are represented by pixels and encoded into particles. The pattern fidelity is adopted as the fitness function to evaluate these particles. The source optimization approach is implemented by updating the velocities and positions of these particles. The approach is demonstrated by using two typical mask patterns, including a periodic array of contact holes and a vertical line/space design. The pattern errors are reduced by 66.1% and 39.3% respectively. Compared with the source optimization approach using genetic algorithm, the proposed approach leads to faster convergence while improving the image quality at the same time. The robustness of the proposed approach to initial sources is also verified.

  18. Academic Plan Year One: Progress and Achievements

    E-print Network

    Academic Plan ­ Year One: Progress and Achievements Faculty of Applied Science & Engineering University of Toronto December 2012 #12; Faculty of Applied Science & Engineering Academic Plan -- Year One: Progress and Achievements 2 of 21 Table of Contents Executive Summary

  19. High School Homework: Increasing Student Achievement.

    ERIC Educational Resources Information Center

    Foyle, Harvey C.; Bailey, Gerald D.

    1986-01-01

    Examines research pertaining to homework and student achievement and concludes that assigning and managing homework do increase achievment. Recommends that schools developing homework policies refer to this research as the basis of their policies.(FL)

  20. Stochastic models for tumoral growth

    NASA Astrophysics Data System (ADS)

    Escudero, Carlos

    2006-02-01

    Strong experimental evidence has indicated that tumor growth belongs to the molecular beam epitaxy universality class. This type of growth is characterized by the constraint of cell proliferation to the tumor border and the surface diffusion of cells at the growing edge. Tumor growth is thus conceived as a competition for space between the tumor and the host, and cell diffusion at the tumor border is an optimal strategy adopted for minimizing the pressure and helping tumor development. Two stochastic partial differential equations are reported in this paper in order to correctly model the physical properties of tumoral growth in (1+1) and (2+1) dimensions. The advantage of these models is that they reproduce the correct geometry of the tumor and are defined in terms of polar variables. An analysis of these models allows us to quantitatively estimate the response of the tumor to an unfavorable perturbation during growth.

  1. Probabilistic methods in combinatorial and stochastic optimization

    E-print Network

    Vondrák, Jan, 1974-

    2005-01-01

    (cont.) Packing/Covering problems, we prove upper and lower bounds on the adaptivity gap depending on the dimension. We also design polynomial-time algorithms achieving near-optimal approximation guarantees with respect ...

  2. A Combined Modeling and Experimental Approach for Achieving a Simplified Closed Ecosystem

    NASA Astrophysics Data System (ADS)

    Turc, H. A.; Pintena, J.; Bagarri, P.; Gibiat, F.; Fabreguettes, V.

    1999-01-01

    In CELSS both biological and physico-chemical processes have to be used to support the main needs of the crews and to minimize the re-supply of food and air from Earth. The basic idea is to create a complete food chain (an artificial ecosystem), beginning from the crew, with its wastes, and returning to the crew to supply it with food and air. Two main other steps of this food chain are a waste treatment process and a biomass production including higher plants. We set up the connection of these key modules, which we called ECLAS (Ecosystème Clos Artificiel Simplifié). A growth chamber containing higher plants is connected to a continuous supercritical water oxidation reactor, that converts the harvested biomass into carbon dioxide and enables the photosynthesis of the canopy. To achieve a stable coupling through optimized regulations between the modules, we programmed a modular numerical simulation of the system, in order to assess the involved fluxes and to constrain the last degrees of freedom of the experimental system already built. Simulation results and the first experimental results are here compared.

  3. Understanding the DNA damage response in order to achieve desired gene editing outcomes in mosquitoes.

    PubMed

    Overcash, Justin M; Aryan, Azadeh; Myles, Kevin M; Adelman, Zach N

    2015-02-01

    Mosquitoes are high-impact disease vectors with the capacity to transmit pathogenic agents that cause diseases such as malaria, yellow fever, chikungunya, and dengue. Continued growth in knowledge of genetic, molecular, and physiological pathways in mosquitoes allows for the development of novel control methods and for the continued optimization of existing ones. The emergence of site-specific nucleases as genomic engineering tools promises to expedite research of crucial biological pathways in these disease vectors. The utilization of these nucleases in a more precise and efficient manner is dependent upon knowledge and manipulation of the DNA repair pathways utilized by the mosquito. While progress has been made in deciphering DNA repair pathways in some model systems, research into the nature of the hierarchy of mosquito DNA repair pathways, as well as in mechanistic differences that may exist, is needed. In this review, we will describe progress in the use of site-specific nucleases in mosquitoes, along with the hierarchy of DNA repair in the context of mosquito chromosomal organization and structure, and how this knowledge may be manipulated to achieve precise chromosomal engineering in mosquitoes. PMID:25596822

  4. Subgroup Achievement and Gap Trends: Oklahoma, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Oklahoma for 2010. Oklahoma made progress in narrowing achievement gaps for most major subgroups on the End-of-Instruction (EOI) test in Algebra I. Trends in achievement gaps could not be determined for other grades in math, or for any grades in reading, because the state…

  5. The Intersection of Culture and Achievement Motivation

    ERIC Educational Resources Information Center

    Trumbull, Elise; Rothstein-Fisch, Carrie

    2011-01-01

    Achievement motivation is something that all members of the school community want to support in students, however few may recognize that it is influenced by culture. The very meaning of "achievement" is culturally variable, and the motives that students have for achieving may be quite different, depending upon their cultural background. The…

  6. Predicting academic achievement with cognitive ability

    Microsoft Academic Search

    Treena Eileen Rohde; Lee Anne Thompson

    2007-01-01

    The purpose of the present study is to explain variation in academic achievement with general cognitive ability and specific cognitive abilities. Grade point average, Wide Range Achievement Test III scores, and SAT scores represented academic achievement. The specific cognitive abilities of interest were: working memory, processing speed, and spatial ability. General cognitive ability was measured with the Raven's Advanced Progressive

  7. Identifying the preferred subset of enzymatic profiles in nonlinear kinetic metabolic models via multiobjective global optimization and Pareto filters.

    PubMed

    Pozo, Carlos; Guillén-Gosálbez, Gonzalo; Sorribas, Albert; Jiménez, Laureano

    2012-01-01

    Optimization models in metabolic engineering and systems biology focus typically on optimizing a unique criterion, usually the synthesis rate of a metabolite of interest or the rate of growth. Connectivity and non-linear regulatory effects, however, make it necessary to consider multiple objectives in order to identify useful strategies that balance out different metabolic issues. This is a fundamental aspect, as optimization of maximum yield in a given condition may involve unrealistic values in other key processes. Due to the difficulties associated with detailed non-linear models, analysis using stoichiometric descriptions and linear optimization methods have become rather popular in systems biology. However, despite being useful, these approaches fail in capturing the intrinsic nonlinear nature of the underlying metabolic systems and the regulatory signals involved. Targeting more complex biological systems requires the application of global optimization methods to non-linear representations. In this work we address the multi-objective global optimization of metabolic networks that are described by a special class of models based on the power-law formalism: the generalized mass action (GMA) representation. Our goal is to develop global optimization methods capable of efficiently dealing with several biological criteria simultaneously. In order to overcome the numerical difficulties of dealing with multiple criteria in the optimization, we propose a heuristic approach based on the epsilon constraint method that reduces the computational burden of generating a set of Pareto optimal alternatives, each achieving a unique combination of objectives values. To facilitate the post-optimal analysis of these solutions and narrow down their number prior to being tested in the laboratory, we explore the use of Pareto filters that identify the preferred subset of enzymatic profiles. We demonstrate the usefulness of our approach by means of a case study that optimizes the ethanol production in the fermentation of Saccharomyces cerevisiae. PMID:23028457

  8. Identifying the Preferred Subset of Enzymatic Profiles in Nonlinear Kinetic Metabolic Models via Multiobjective Global Optimization and Pareto Filters

    PubMed Central

    Pozo, Carlos; Guillén-Gosálbez, Gonzalo; Sorribas, Albert; Jiménez, Laureano

    2012-01-01

    Optimization models in metabolic engineering and systems biology focus typically on optimizing a unique criterion, usually the synthesis rate of a metabolite of interest or the rate of growth. Connectivity and non-linear regulatory effects, however, make it necessary to consider multiple objectives in order to identify useful strategies that balance out different metabolic issues. This is a fundamental aspect, as optimization of maximum yield in a given condition may involve unrealistic values in other key processes. Due to the difficulties associated with detailed non-linear models, analysis using stoichiometric descriptions and linear optimization methods have become rather popular in systems biology. However, despite being useful, these approaches fail in capturing the intrinsic nonlinear nature of the underlying metabolic systems and the regulatory signals involved. Targeting more complex biological systems requires the application of global optimization methods to non-linear representations. In this work we address the multi-objective global optimization of metabolic networks that are described by a special class of models based on the power-law formalism: the generalized mass action (GMA) representation. Our goal is to develop global optimization methods capable of efficiently dealing with several biological criteria simultaneously. In order to overcome the numerical difficulties of dealing with multiple criteria in the optimization, we propose a heuristic approach based on the epsilon constraint method that reduces the computational burden of generating a set of Pareto optimal alternatives, each achieving a unique combination of objectives values. To facilitate the post-optimal analysis of these solutions and narrow down their number prior to being tested in the laboratory, we explore the use of Pareto filters that identify the preferred subset of enzymatic profiles. We demonstrate the usefulness of our approach by means of a case study that optimizes the ethanol production in the fermentation of Saccharomyces cerevisiae. PMID:23028457

  9. Suitable Conditions for Mycelial Growth of Phellinus spp.

    PubMed Central

    Hur, Hyun; Imtiaj, Ahmed; Lee, Min Woong

    2008-01-01

    The fungus Phellinus is a mushroom that is widely used medicinally. The optimal conditions for mycelial growth of 13 strains of the fungus were investigated. Mycelial growth was optimal at 25? and was uniformly minimal at 15? and 35?. Growth was optimal at pH 6~7. The mycelial phenotype was best promoted by growth using Potato Dextrose agar, Hamada, Glucose peptone, and Yeast-Malt media, whereas Czapek Dox, Hennerberg, and Lilly media were the most unfavorable for the mycelial growth of Phellinus spp. Glucose, sucrose, fructose, and dextrin were the most suitable carbon sources for mycelial growth, while lactose, maltose, and galactose were unsuitable. Among tested nitrogen sources, ammonium phosphate, potassium nitrate, and arginine best promoted mycelial growth, while alanine, urea, and histidine least promoted mycelial growth. PMID:23997616

  10. Shape-preserving computation in economic growth models

    Microsoft Academic Search

    Sheng-pen Wang

    2001-01-01

    We point out the shape characteristics — monotonicity and concavity — of the value functions of optimal economic growth problems. We introduce the concept of shape preservation in approximating the value functions. We also present a shape-preserving algorithm to compute the solutions of continuous-state optimal economic growth problems. Numerical results show that shape-preserving interpolation methods are superior to others with

  11. Biphasic growth in fish I: theoretical foundations.

    PubMed

    Quince, Christopher; Abrams, Peter A; Shuter, Brian J; Lester, Nigel P

    2008-09-21

    We develop the theory of biphasic somatic growth in fish using models based on the distinction between pre- and post-maturation growth and an explicit description of energy allocation within a growing season. We define a 'generic biphasic' (GB) model that assumes post-maturation growth has a von Bertalanffy (vB) form. For this model we derive an explicit expression for the gonad weight/somatic weight ratio (g) which may either remain fixed or vary with size. Optimal biphasic models are then developed with reproductive strategies that maximise lifetime reproductive output. We consider two optimal growth models. In the first (fixed g optimal), gonad weight is constrained to be proportional to somatic weight. In the second (variable g optimal) model, allocation to reproduction is unconstrained and g increases with size. For the first of these two models, adult growth in a scaled measure of length has the exact vB form. When there are no constraints on allocation, growth is vB to a very good approximation. In both models, pre-maturation growth is linear. In a companion paper we use growth data from lake trout (Salvelinus namaycush) to test the bioenergetics assumptions used to develop these models, and demonstrate that they have advantages over the vB model, both in quality of fit, and in the information contained in the fitted parameters. PMID:18606423

  12. Environmental policy, pollution, unemployment, and endogenous growth

    Microsoft Academic Search

    Søren Bo Nielsen; Lars Haagen Pedersen; Peter Birch Sørensen

    1995-01-01

    The paper develops a model of endogenous economic growth with pollution externalities and a labor market distorted by union monopoly power and by taxes and transfers. We study the optimal second-best pollution tax and abatement policy and find that a shift toward greener preferences will tend to reduce unemployment, although it will hamper growth. We also find that greater labor-market

  13. Protandry, sexual size dimorphism, and adaptive growth.

    PubMed

    Morbey, Yolanda E

    2013-12-21

    Adaptive growth refers to the strategic adjustment of growth rate by individuals to maximize some component of fitness. The concept of adaptive growth proliferated in the 1990s, in part due to an influential theoretical paper by Peter Abrams and colleagues. In their 1996 paper, Abrams et al. explored the effects of time stress on optimal growth rate, development time, and adult size in seasonal organisms. In this review, I explore how the concept of adaptive growth informs our understanding of protandry (the earlier arrival of males to sites of reproduction than females) and sexual size dimorphism in seasonal organisms. I conclude that growth rate variation is an important mechanism that helps to conserve optimal levels of protandry and sexual size dimorphism in changing environments. PMID:23688825

  14. Integrated multidisciplinary design optimization of rotorcraft

    NASA Technical Reports Server (NTRS)

    Adelman, Howard M.; Mantay, Wayne R.

    1989-01-01

    The NASA/Army research plan for developing the logic elements for helicopter rotor design optimization by integrating appropriate disciplines and accounting for important interactions among the disciplines is discussed. The optimization formulation is described in terms of the objective function, design variables, and constraints. The analysis aspects are discussed, and an initial effort at defining the interdisciplinary coupling is summarized. Results are presented on the achievements made in the rotor dynamic optimization for vibration reduction, rotor structural optimization for minimum weight, and integrated aerodynamic load/dynamics optimization for minimum vibration and weight.

  15. Growth Mindset

    NSDL National Science Digital Library

    2012-01-01

    This page from Character Lab presents information about what a growth mindset is, why it is important and how to develop it. Included is a 3-minute video of Drs. Carol Dweck and Greg Walton of Stanford University discussing how a growth mindset compares to a fixed mindset.

  16. Capacity achieving modulation format for high-speed optical networks

    NASA Astrophysics Data System (ADS)

    Batshon, Hussam G.; Djordjevic, Ivan B.; Xu, Lei; Wang, Ting

    2010-01-01

    In recent years, we have witnessed an increased demand on optical-networks transmission-capacities due to the growing popularity of the Internet and multimedia in everyday life. According to industry expert estimates, 1Tb/s-Ethernet should be standardized by the year 2012-2013. To this end, we propose a non-uniform modulation format that achieves the channel capacity for SNRs of up to 25dB. The proposed modulation format is optimized for ASE-noise-dominated channels and can achieve 400Gb/s data rate per polarization utilizing the currently-available components operating at 50-GSymbols/s. One major benefit of the current scheme is that it is an affordable upgrade to the current systems.

  17. Transmitter optimization and optimality of beamforming for multiple antenna systems

    Microsoft Academic Search

    Syed Ali Jafar; Andrea J. Goldsmith

    2004-01-01

    Abstract: We solve the transmitter optimization problem and determine a necessary and sucient condition underwhich beamforming achieves Shannon capacity in a narrowband point to point communication system employingmultiple transmit and receive antennas. We assume perfect channel state information at the receiver(CSIR) and imperfect channel state feedback from the receiver to the transmitter. We consider the cases ofmean and covariance feedback.

  18. Web-dendritic ribbon growth

    NASA Technical Reports Server (NTRS)

    Hilborn, R. B., Jr.; Faust, J. W., Jr.

    1976-01-01

    A web furnace was constructed for pulling dendritic-web samples. The effect of changes in the furnace thermal geometry on the growth of dendritic-web was studied. Several attempts were made to grow primitive dendrites for use as the dendritic seed crystals for web growth and to determine the optimum twin spacing in the dendritic seed crystal for web growth. Mathematical models and computer programs were used to determine the thermal geometries in the susceptor, crucible melt, meniscus, and web. Several geometries were determined for particular furnace geometries and growth conditions. The information obtained was used in conjunction with results from the experimental growth investigations in order to achieve proper conditions for sustained pulling of two dendrite web ribbons. In addition, the facilities for obtaining the following data were constructed: twin spacing, dislocation density, web geometry, resistivity, majority charge carrier type, and minority carrier lifetime.

  19. The limits of technological optimism

    Microsoft Academic Search

    Andrew D. Basiago

    1994-01-01

    Summary ‘Technological optimism’ is the doctrine that a growing number of technological improvements in such areas as food production, environmental quality and energy will sustain life as human population soars. It evolved as a response to the Malthusian study The Limits to Growth (The Club of Rome, 1972). Like population biologist Paul Ehrlich, Professor James Krier of the University of

  20. Comprehensive Evaluation of Biological Growth Control by Chlorine-Based Biocides in Power Plant Cooling Systems Using Tertiary Effluent

    PubMed Central

    Chien, Shih-Hsiang; Dzombak, David A.; Vidic, Radisav D.

    2013-01-01

    Abstract Recent studies have shown that treated municipal wastewater can be a reliable cooling water alternative to fresh water. However, elevated nutrient concentration and microbial population in wastewater lead to aggressive biological proliferation in the cooling system. Three chlorine-based biocides were evaluated for the control of biological growth in cooling systems using tertiary treated wastewater as makeup, based on their biocidal efficiency and cost-effectiveness. Optimal chemical regimens for achieving successful biological growth control were elucidated based on batch-, bench-, and pilot-scale experiments. Biocide usage and biological activity in planktonic and sessile phases were carefully monitored to understand biological growth potential and biocidal efficiency of the three disinfectants in this particular environment. Water parameters, such as temperature, cycles of concentration, and ammonia concentration in recirculating water, critically affected the biocide performance in recirculating cooling systems. Bench-scale recirculating tests were shown to adequately predict the biocide residual required for a pilot-scale cooling system. Optimal residuals needed for proper biological growth control were 1, 2–3, and 0.5–1?mg/L as Cl2 for NaOCl, preformed NH2Cl, and ClO2, respectively. Pilot-scale tests also revealed that Legionella pneumophila was absent from these cooling systems when using the disinfectants evaluated in this study. Cost analysis showed that NaOCl is the most cost-effective for controlling biological growth in power plant recirculating cooling systems using tertiary-treated wastewater as makeup. PMID:23781129

  1. Comprehensive Evaluation of Biological Growth Control by Chlorine-Based Biocides in Power Plant Cooling Systems Using Tertiary Effluent.

    PubMed

    Chien, Shih-Hsiang; Dzombak, David A; Vidic, Radisav D

    2013-06-01

    Recent studies have shown that treated municipal wastewater can be a reliable cooling water alternative to fresh water. However, elevated nutrient concentration and microbial population in wastewater lead to aggressive biological proliferation in the cooling system. Three chlorine-based biocides were evaluated for the control of biological growth in cooling systems using tertiary treated wastewater as makeup, based on their biocidal efficiency and cost-effectiveness. Optimal chemical regimens for achieving successful biological growth control were elucidated based on batch-, bench-, and pilot-scale experiments. Biocide usage and biological activity in planktonic and sessile phases were carefully monitored to understand biological growth potential and biocidal efficiency of the three disinfectants in this particular environment. Water parameters, such as temperature, cycles of concentration, and ammonia concentration in recirculating water, critically affected the biocide performance in recirculating cooling systems. Bench-scale recirculating tests were shown to adequately predict the biocide residual required for a pilot-scale cooling system. Optimal residuals needed for proper biological growth control were 1, 2-3, and 0.5-1?mg/L as Cl2 for NaOCl, preformed NH2Cl, and ClO2, respectively. Pilot-scale tests also revealed that Legionella pneumophila was absent from these cooling systems when using the disinfectants evaluated in this study. Cost analysis showed that NaOCl is the most cost-effective for controlling biological growth in power plant recirculating cooling systems using tertiary-treated wastewater as makeup. PMID:23781129

  2. A variable scale ant colony algorithm to the optimization of beer recipe

    Microsoft Academic Search

    Song Zheng; Ming Ge; Chunli Wang; Rutian Sun

    2010-01-01

    The optimization of beer recipe is a powerful approach to improve the efficiency of beer company. But for recipe optimization problems, the traditional mathematical optimization methods achieve more complex and lack the robust search for the optimal solution. Ant colony algorithm (ACA) is fit to solve the combinatorial optimization problems, but it has disadvantage of slow convergence and time-consuming in

  3. A novel growth strategy and characterization of fully relaxed un-tilted FCC GaAs on Si(1 0 0)

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Partha; Kumar, Rahul; Ghosh, Saptarsi; Chakraborty, Apurba; Bag, Ankush; Kabi, Sanjib; Banerji, Pallab; Biswas, Dhrubes

    2015-05-01

    A novel growth strategy for GaAs epilayer on Si(1 0 0) has been developed with AlAs/GaAs strained layer superlattice to achieve high crystalline quality for device applications. Emphasis has been given on understanding the inconclusive crystalline morphology of the initial layers by comprehensive material characterization. The influence of growth conditions have been studied by varying the growth temperatures, rates and V/III flux ratios. In-situ RHEED observations throughout the growth guided us to recognize the impact of individual growth parameters on the crystalline morphology. All the four stages of growth have been carried out by molecular beam epitaxy. The optimization of growth parameters at every stage initiates the formation of GaAs face centered cubic crystal from the very beginning. Material characterizations include AFM, HRTEM and HRXRD. The latter one, for the first time witnessed the intensity of superlattice satellite peaks in the fourth order. Low values of threading dislocation propagating to the top surface have been seen in HRTEM with absence of anti-phase boundaries (APB). Results for extended dislocations and surface roughness have been observed to be in the order of 106 cm-2 and 2 nm, respectively which is among the best reported values till date. Significant reduction of extended dislocations has been observed under strain fields in the superlattice. Notably, lower alloy mixing due to the optimized growth of AlAs/GaAs resulted in a suitable thermal behavioral platform as required for device applications. Fully relaxed, un-tilted, APB free, single domain and smooth GaAs epilayers have been achieved which paves the pathway to on-wafer integration of high performance III-Arsenide devices with Si logic circuits.

  4. Assessing ODE models of tumor growth

    NASA Astrophysics Data System (ADS)

    Dobrovolny, Hana; Jaafari, Hana; Ellis, Michael

    2014-03-01

    Mathematical models are often used to study and optimize treatment of cancer. In order to accurately predict the efficacy of a particular treatment, the model must correctly describe tumor growth. Over the years, several differential equation models of tumor growth have been proposed and independently fit to experimental data sets. While all the models provide reasonable fits to tumor growth data, the models have never been confronted with the same experimental data to determine whether any of the models provides a more accurate description of tumor growth. We collected tumor growth data from the literature and fit the various tumor growth models to the data to determine which model best describes tumor growth. Our results indicate that no single model can capture the variety of growth behavior captured in experiments.

  5. Optimal ecosystem management with structural dynamics

    Microsoft Academic Search

    Rui Pedro Mota; Tiago Domingos

    2004-01-01

    We address the problem of optimal management of a self organizing ecosystem along ecological succession. A dynamic carrying capacity is interpreted as depicting the dynamics of habitat creation and occupation along ecological succession. The ecosystem may have three growth modes: pure compensation (concave ecosystem regeneration function), depensation (convex-concave regeneration function) and critical depensation (additionally having negative growth rates for low

  6. Marmot: an optimizing compiler for Java

    Microsoft Academic Search

    Robert P. Fitzgerald; Todd B. Knoblock; Erik Ruf; Bjarne Steensgaard; David Tarditi

    2000-01-01

    The Marmot system is a research platform for studying the implementation of high level programming languages. It currently comprises an optimizing native code compiler, runtime system, and libraries for a large subset of Java. Marmot integrates well-known representation, optimization, code generation, and runtime techniques with a few Java-specific features to achieve competitive performance. This paper contains a description of the

  7. Optimal Carbon Capture and Storage Policies

    Microsoft Academic Search

    Alain Ayong Le Kama; Mouez Fodha; Gilles Lafforgue

    2009-01-01

    Following the IPCC's report (2005), which recommended the development and the use of carbon capture and sequestration (CCS) technologies in order to achieve the environmental goals, defined by the Kyoto Protocol, the issue addressed in this paper concerns the optimal strategy regarding the long-term use of CCS technologies. The aim of this paper is to study the optimal carbon capture

  8. Dynamics of Achievement: Differential Growth of Achievement for Negro and White Students by SMSA/non-SMSA and Region.

    ERIC Educational Resources Information Center

    Okada, Tetsuo; Stoller, David S.

    When comparisons of average test score results or grade level equivalents are made in terms of Negro and white students by standard metropolitan statistical areas (SMSA), non-SMSA, and within regions, white students in every region, regardless whether metropolitan or nonmetropolitan, have higher average scores in every type of test at every grade…

  9. van der Waals epitaxial growth of graphene on sapphire by chemical vapor deposition without a metal catalyst.

    PubMed

    Hwang, Jeonghyun; Kim, Moonkyung; Campbell, Dorr; Alsalman, Hussain A; Kwak, Joon Young; Shivaraman, Shriram; Woll, Arthur R; Singh, Arunima K; Hennig, Richard G; Gorantla, Sandeep; Rümmeli, Mark H; Spencer, Michael G

    2013-01-22

    van der Waals epitaxial growth of graphene on c-plane (0001) sapphire by CVD without a metal catalyst is presented. The effects of CH(4) partial pressure, growth temperature, and H(2)/CH(4) ratio were investigated and growth conditions optimized. The formation of monolayer graphene was shown by Raman spectroscopy, optical transmission, grazing incidence X-ray diffraction (GIXRD), and low voltage transmission electron microscopy (LVTEM). Electrical analysis revealed that a room temperature Hall mobility above 2000 cm(2)/V·s was achieved, and the mobility and carrier type were correlated to growth conditions. Both GIXRD and LVTEM studies confirm a dominant crystal orientation (principally graphene [10-10] || sapphire [11-20]) for about 80-90% of the material concomitant with epitaxial growth. The initial phase of the nucleation and the lateral growth from the nucleation seeds were observed using atomic force microscopy. The initial nuclei density was ~24 ?m(-2), and a lateral growth rate of ~82 nm/min was determined. Density functional theory calculations reveal that the binding between graphene and sapphire is dominated by weak dispersion interactions and indicate that the epitaxial relation as observed by GIXRD is due to preferential binding of small molecules on sapphire during early stages of graphene formation. PMID:23244231

  10. Growth and the Premature Baby

    Microsoft Academic Search

    A. Gibson; S. Carney; J. K. H. Wales

    2006-01-01

    There is considerable evidence to show that babies born prematurely have poor postnatal growth, and the more premature the baby, the greater the impairment is likely to be and the longer it will persist. Nutrition has been shown to play an important part in this, but adequate nutrition is difficult, if not impossible, to achieve in these infants. In the

  11. Optimal Quantum Cloning via Stimulated Emission

    NASA Astrophysics Data System (ADS)

    Simon, Christoph; Weihs, Gregor; Zeilinger, Anton

    2000-03-01

    We show that optimal universal quantum cloning can be realized via stimulated emission. Universality of the cloning procedure is achieved by choosing systems that have appropriate symmetries. We first discuss a scheme based on stimulated emission in certain three-level systems, e.g., atoms in a cavity. Then we present a way of realizing optimal universal cloning based on stimulated parametric down-conversion. This scheme also implements the optimal universal NOT operation.

  12. Dispositional Optimism

    PubMed Central

    Carver, Charles S.; Scheier, Michael F.

    2014-01-01

    Optimism is a cognitive construct (expectancies regarding future outcomes) that also relates to motivation: optimistic people exert effort, whereas pessimistic people disengage from effort. Study of optimism began largely in health contexts, finding positive associations between optimism and markers of better psychological and physical health. Physical health effects likely occur through differences in both health-promoting behaviors and physiological concomitants of coping. Recently, the scientific study of optimism has extended to the realm of social relations: new evidence indicates that optimists have better social connections, partly because they work harder at them. In this review, we examine the myriad ways this trait can benefit an individual, and our current understanding of the biological basis of optimism. PMID:24630971

  13. Linear theory for optimal control of molecular wave packets

    Microsoft Academic Search

    Jianshu Cao; Kent R. Wilson

    1997-01-01

    A linear theory for optimizing optical fields to achieve a molecular configuration at a chosen time is formulated with an emphasis on the symmetric transformation between time domain and space domain representations. Based on two different measures of control, the yield and achievement functions, two parallel but distinct optimization schemes are derived in a unified algebraic format. Connections are then

  14. Advanced Optimization Strategies in the Rice dHPF Compiler

    Microsoft Academic Search

    J. Mellor-Crummey; V. Adve; B. Broom; Chavarr ´ õa-Miranda; R. Fowler; G. Jin; K. Kennedy; Q. Yi

    2001-01-01

    SUMMARY High Performance Fortran (HPF) was envisioned as a vehicle for modernizing legacy Fortran codes to achieve scalable parallel performance. To a large extent, today's commercially available HPF compilers have failed to deliver scalable parallel performance for a broad spectrum of applications because of insufficiently powerful compiler analysis and optimization. Substantial restructuring and hand- optimization can be required to achieve

  15. Optimal flux weakening in surface PM machines using concentrated windings

    Microsoft Academic Search

    Ayman M. EL-Refaie; Thomas M. Jahns

    2004-01-01

    A design approach is presented for achieving optimal flux weakening operation in surface PM synchronous machines by properly designing the machine's stator windings using concentrated, fractional-slot stator windings. This technique makes it possible to significantly increase the machine inductance in order to achieve the critical condition for providing wide speed ranges of constant-power operation. The conditions for optimal flux weakening

  16. Optimal energy management and recovery for FEV

    Microsoft Academic Search

    Kosmas Knoedler; Jochen Steinmann; Sylvain Laversanne; Stephen Jones; Arno Huss; Emre Kural; David Sanchez; Oliver Bringmann; Jochen Zimmermann

    2012-01-01

    This paper briefly describes the latest achievements of a new functional vehicle system to overcome the range anxiety problem of Fully Electric Vehicles (FEV). This is primarily achieved by integrated control and operation strategies to optimize the driving range. The main focus of these control strategies is cooperated electric drivetrain and regenerative braking system. The diverse source of information with

  17. Portugal's Growth Paradox, 1870-1950

    Microsoft Academic Search

    Pedro Lains

    2003-01-01

    From 1870 to 1913, the Portuguese economy expanded slowly and diverged from the European core. Contrarily, in the interwar period, Portugal achieved higher growth and partially caught-up to the levels of productivity of Western Europe. Higher growth in Portugal after World War I occurred in a framework of protection, increasing state intervention, and capital deepening. Agriculture responded more positively than

  18. Antecedents of students' achievement in statistics

    NASA Astrophysics Data System (ADS)

    Awaludin, Izyan Syazana; Razak, Ruzanna Ab; Harris, Hezlin; Selamat, Zarehan

    2015-02-01

    The applications of statistics in most fields have been vast. Many degree programmes at local universities require students to enroll in at least one statistics course. The standard of these courses varies across different degree programmes. This is because of students' diverse academic backgrounds in which some comes far from the field of statistics. The high failure rate in statistics courses for non-science stream students had been concerning every year. The purpose of this research is to investigate the antecedents of students' achievement in statistics. A total of 272 students participated in the survey. Multiple linear regression was applied to examine the relationship between the factors and achievement. We found that statistics anxiety was a significant predictor of students' achievement. We also found that students' age has significant effect to achievement. Older students are more likely to achieve lowers scores in statistics. Student's level of study also has a significant impact on their achievement in statistics.

  19. Identification of components to optimize improvement in system reliability

    SciTech Connect

    Painton, L. [Carnegie-Mellon Univ., Pittsburgh, PA (United States). Dept. of Engineering and Public Policy; Campbell, J. [Sandia National Labs., Albuquerque, NM (United States)

    1993-10-01

    The fields of reliability analysis and risk assessment have grown dramatically since the 1970s. There are now bodies of literature and standard practices which cover quantitative aspects of system analysis such as failure rate and repair models, fault and event tree generation, minimal cut sets, classical and Bayesian analysis of reliability, component and system testing techniques, decomposition methods, etc. In spite of the growth in the sophistication of reliability models, however, little has been done to integrate optimization models within a reliability analysis framework. That is, often reliability models focus on characterization of system structure in terms of topology and failure/availability characteristics of components. A number of approaches have been proposed to help identify the components of a system that have the largest influence on overall system reliability. While this may help rank order the components, it does not necessarily help a system design team identify which components they should improve to optimize overall reliability (it may be cheaper and more effective to focus on improving two or three components of smaller importance than one component of larger importance). In this paper, we present an optimization model that identifies the components to be improved to maximize the increase in system MTBF, subject to a fixed budget constraint. A dual formulation of the model is to minimize cost, subject to achieving a certain level of system reliability.

  20. Elementary Mathematics Specialists: Influencing Student Achievement

    NSDL National Science Digital Library

    Patricia F. Campbell

    This 8-page article (PDF) details a three-year research study on the impact of math specialists on student achievement in grades 3-5. While the article reports that student achievement did not immediately improve in the first year, student achievement did improve significantly in subsequent years. The article includes a description of the preparation the math specialists had and their role once placed in their schools.

  1. Student achievement in science: A longitudinal look at individual and school differences

    NASA Astrophysics Data System (ADS)

    Martinez, Alina

    The importance of science in today's technological society necessitates continued attention to students' experiences in science and specifically their achievement in science. There is a need to look at gender and race/ethnicity simultaneously when studying students' experiences in science and to explore factors related to higher achievement among students. Using data from the Longitudinal Study of American Youth, this study contributes to existing literature on student achievement in science by simultaneously exploring the effects of race/ethnicity and gender. Capitalizing on the availability of yearly science achievement scores, I present trajectories of student achievement from 7th to 12th grade. This study also includes an exploration of school effects. Overall, student achievement in science increases from 7th to 12th grade, although some leveling is seen in later grades. Growth in achievement differs by both gender and race/ethnicity, but racial/ethnic differences are larger than gender differences. Hispanic, Black, Asian, and White males score higher, on average, throughout the secondary grades than their female counterparts. Achievement scores of Asian students are consistently higher than White students, who in turn score higher than Hispanic and finally Black students. Both background and science-related factors help explain variation in achievement status and growth in achievement. Parental education is positively associated with achievement status among all groups except Black students for whom there is no effect of parental education. Science related resources in the home are positively associated with student achievement and the effect of these resources increases in later grades. Student achievement in science is also positively related to student course taking and attitude toward science. Furthermore, both the negative effect of viewing science as a male domain, which exists for males and females, and the positive effect of parental support for science increase in magnitude in later grades. Thirteen percent of the variation in achievement was found to occur between schools. At the school level, student/teacher ratio is positively related to student achievement in 7th grade and the percent of students who receive free lunch in a school is negatively related to achievement, but neither of these is related to growth in achievement over time.

  2. Growth chart

    MedlinePLUS

    Height and weight chart ... Growth charts are used to compare your child's height, weight, and head size against children of the ... From these numbers, the national average weight and height for each age and gender were established. The ...

  3. USF Firsts, Facts, Honors, and Achievements,

    E-print Network

    Galles, David

    ................................................................................................................................................................................. 4 Diversity....................................................................................................................................26 USF School of Nursing and Health Professions: Firsts, Facts, Honors, and Achievements­2012....................................................................................................................................................................................................................28 School of Nursing and Health Professions: Prominent Alumni..............................................................................

  4. Brandeis Academic Achievement Award What is the Brandeis Academic Achievement Award?

    E-print Network

    Snider, Barry B.

    Brandeis Academic Achievement Award What is the Brandeis Academic Achievement Award? The Brandeis Academic Achievement Award (BAAA) was developed by the Office of Students and Enrollment, in conjunction is to recognize outstanding scholarship and academic achievement as evidenced by grades, faculty recommendations

  5. The effect of CAS calculator usage on the Algebra Achievement of Low Mathematics achievement students

    Microsoft Academic Search

    Hee-Chan Lew

    This paper observed the effect of CAS calculator usage while studying algebra on the achievement of low- achievement students in mathematics, here in referred to as low-achievement students. Participants were composed of 70 low-achievement tenth graders from a high school located in a metropolitan city that had never used a mathematics educational calculator before. Target participants were divided into two

  6. Need for achievement and cortisol 1 Running head: NEED FOR ACHIEVEMENT AND CORTISOL

    E-print Network

    Schultheiss, Oliver C.

    Need for achievement and cortisol 1 Running head: NEED FOR ACHIEVEMENT AND CORTISOL Implicit need for achievement predicts attenuated cortisol responses to difficult tasks Oliver C. Schultheiss Friedrich, Germany, email: oliver.schultheiss@psy.phil.uni-erlangen.de #12;Need for achievement and cortisol 2

  7. Trajectories of Math and Reading Achievement in Low-Achieving Children in Elementary School: Effects of Early and Later Retention in Grade

    ERIC Educational Resources Information Center

    Moser, Stephanie E.; West, Stephen G.; Hughes, Jan N.

    2012-01-01

    This study investigated the effects of retention or promotion in 1st grade on growth trajectories in mathematics and reading achievement over the elementary school years (Grades 1-5). From a large multiethnic sample (n = 784) of children who were below the median in literacy at school entrance, 363 children who were either promoted (n = 251) or…

  8. Enhanced Cellulase Production from Bacillus subtilis by Optimizing Physical Parameters for Bioethanol Production.

    PubMed

    Deka, Deepmoni; Das, Saprativ P; Sahoo, Naresh; Das, Debasish; Jawed, Mohammad; Goyal, Dinesh; Goyal, Arun

    2013-01-01

    Effect of physical parameters such as initial pH, agitation (rpm), and temperature (°C) for cellulase production from Bacillus subtilis AS3 was investigated. Central composite design of experiments followed by multiple desirability function was applied for the optimization of cellulase activity and cell growth. The effect of the temperature and agitation was found to be significant among the three independent variables. The optimum levels of initial pH, temperature, and agitation for alkaline carboxymethylcellulase (CMCase) production predicted by the model were 7.2, 39°C, and 121?rpm, respectively. The CMCase activity with unoptimized physical parameters and previously optimized medium composition was 0.43?U/mL. The maximum activity (0.56?U/mL) and cell growth (2.01?mg/mL) predicted by the model were in consensus with values (0.57?U/mL, 2.1?mg/mL) obtained using optimized medium and optimal values of physical parameters. After optimization, 33% enhancement in CMCase activity (0.57?U/mL) was recorded. On scale-up of cellulase production process in bioreactor with all the optimized conditions, an activity of 0.75?U/mL was achieved. Consequently, the bacterial cellulase employed for bioethanol production expending (5%, w/v) NaOH-pretreated wild grass with Zymomonas mobilis yielded an utmost ethanol titre of 7.56?g/L and 11.65?g/L at shake flask and bioreactor level, respectively. PMID:25937985

  9. Real-Time Utility System Optimization 

    E-print Network

    Fernandez-Polanco, D.; Eastwood, A.; Knight, N.

    2004-01-01

    utility models for customers in all sectors of process industry. These models were originally developed as simulators to verify the actual cost savings in imported energy that would be achieved from our recommended energy saving projects within...% of energy costs over and above those achieved by an earlier, in- house optimizer. This saving amounts to millions of dollars per year at that facility. We have also completed models for large companies in the US and Canada, all of which are achieving...

  10. The characteristics and strategies of high growth SMEs

    Microsoft Academic Search

    David Smallbone; Roger Leig; David North

    1995-01-01

    Based on an empirical investigation of the development of a group of manufacturing SMEs comparing the characteristics and strategies of firms achieving high growth between 1979-90 with the weaker performing companies. Shows that high growth can be achieved by firms with a variety of size, sector and age characteristics; such firms are distinguished more by the strategies and actions of

  11. Microrobotic Streak Seeding For Protein Crystal Growth CUCS04104

    E-print Network

    Microrobotic Streak Seeding For Protein Crystal Growth CUCS­041­04 Atanas Georgiev 1 Peter Allen 1 that consists of picking individual protein crystal from growth solution the purpose X­ray data collection) transferred protein solution that optimized their growth. building high­throughput protein crystal production

  12. The role of phytochelates in plant growth and productivity

    Microsoft Academic Search

    A. M. Kinnersley

    1993-01-01

    Plants require minimal amounts of certain metals (Zn,Fe,Cu,etc) for optimal growth and productivity, but excess of these metals leads to cell death. When growth is limited by metal excess or metal deficiency plants respond by synthesizing nonproteinogenic chelating substances. Phytosiderophores are secreted by roots of iron deficient grasses and are important in providing sufficient Fe for normal growth. In response

  13. Mathematical Optimization

    NSDL National Science Digital Library

    Leske, Cavin.

    Some of the most fundamental problems in engineering, science, and mathematics would take the most powerful computer in the world several lifetimes to find an optimal solution. However, near-optimal solutions to many of these problems have been discovered thanks to various methods of mathematical optimization. This Topic in Depth looks at some optimization techniques and the areas to which they have been applied.Argonne National Laboratory hosts an online guide (1) to some of the most well known optimization problems and algorithms. People who are new to the subject can find a wealth of introductory material in the Optimization Tree section, and several applications are illustrated with interactive demonstrations in the Case Studies section. Optimization has roots in operations research, and this tutorial (2) covers many topics within OR. A fun applet requires the user to place as many queens on a chess board as possible without any two being in direct line-of-sight, and an accompanying discussion shows how linear programming can be used to solve this problem; this is one of many resources contained within the tutorial. Two chemical engineering professors at Carnegie Mellon University are the authors of Retrospective on Optimization (3), a fairly comprehensive paper chronicling the history of optimization problems and the development of solution methods. The 51-page document is divided into two main parts; the first outlines some of the most significant advances in the field, and the second looks ahead toward key areas of research needed to evolve optimization further. Highway planning and development is the focus of this paper (4), which proposes using, among other things, genetic algorithms to optimize highway alignment. The authors state that this technique could be used to avoid delays and added costs due to changing plans later in the construction process. Another use of genetic algorithms in optimization is highlighted in this document from the German Aerospace Center (5). The document describes how a novel method for robot design, which involves formulating mathematical representations of robotic constraints and kinematics. These figures can then be used as parameters in a genetic algorithm that would optimize component placement while maintaining the desired functionality. A joint effort between architecture and mechanical engineering researchers at the University of Michigan (6) applied geometrical and topological optimization techniques to building floorplan layout. In the course of their research, they developed an optimization tool that is briefly described and can be downloaded from a Web site given in the paper. The Mathematical Programming Glossary (7) contains short discussions of hundreds of terms related to optimization theory. Each entry includes a clear definition and hyperlinks to other terms, and some of the entries are accompanied by a more in-depth supplement. One of the best sources for current research papers and reports is Optimization Online (8). This repository receives numerous submissions each month, and papers can be browsed by data added or category.

  14. Achievement incentives determine the effects of achievement-motive incongruence on flow experience

    Microsoft Academic Search

    Julia Schüler

    2010-01-01

    Previous research has shown that incongruence between implicit and explicit achievement motives impairs flow experience. We\\u000a examined this relationship in a more differentiated manner by arguing that achievement-motive incongruence only exerts negative\\u000a effects when individuals act in situations in which achievement incentives are present and arouse conflict between the two\\u000a motives. In non-achievement situations, no negative effects of achievement-motive incongruence

  15. Numerical Simulation of Nanostructure Growth

    NASA Technical Reports Server (NTRS)

    Hwang, Helen H.; Bose, Deepak; Govindan, T. R.; Meyyappan, M.

    2004-01-01

    Nanoscale structures, such as nanowires and carbon nanotubes (CNTs), are often grown in gaseous or plasma environments. Successful growth of these structures is defined by achieving a specified crystallinity or chirality, size or diameter, alignment, etc., which in turn depend on gas mixture ratios. pressure, flow rate, substrate temperature, and other operating conditions. To date, there has not been a rigorous growth model that addresses the specific concerns of crystalline nanowire growth, while demonstrating the correct trends of the processing conditions on growth rates. Most crystal growth models are based on the Burton, Cabrera, and Frank (BCF) method, where adatoms are incorporated into a growing crystal at surface steps or spirals. When the supersaturation of the vapor is high, islands nucleate to form steps, and these steps subsequently spread (grow). The overall bulk growth rate is determined by solving for the evolving motion of the steps. Our approach is to use a phase field model to simulate the growth of finite sized nanowire crystals, linking the free energy equation with the diffusion equation of the adatoms. The phase field method solves for an order parameter that defines the evolving steps in a concentration field. This eliminates the need for explicit front tracking/location, or complicated shadowing routines, both of which can be computationally expensive, particularly in higher dimensions. We will present results demonstrating the effect of process conditions, such as substrate temperature, vapor supersaturation, etc. on the evolving morphologies and overall growth rates of the nanostructures.

  16. Optimal Shape Design of microfluidic devices for viscoelastic fluid flow

    Microsoft Academic Search

    Manuel A. Alves

    In this work we describe an integrated algorithm for optimal shape design of viscoelastic fluid flow. For this purpose we couple a finite-volume viscoelastic code (1) with the CONDOR optimizer (2) and a fully automated mesh generation and adaptation procedure. The main goal is to find the shape of a given flow geometry, in order to achieve optimal performance. We

  17. Near-optimal control of linear multiparameter singularly perturbed systems

    Microsoft Academic Search

    Hiroaki Mukaidani; Tetsu Shimomura; Hua Xu

    2002-01-01

    In this note, the linear quadratic optimal control for multipa- rameter singularly perturbed systems is studied. The attention is focused on the design of a new near-optimal controller. The resulting controller achieves approximation of the optimal cost. The proposed algorithm has been numerically tested on a real physical example and pro- duced useful results.

  18. Optimal load distribution in series–parallel systems

    Microsoft Academic Search

    Gregory Levitin; Suprasad V. Amari

    2009-01-01

    This paper presents an algorithm for determining an optimal loading of elements in series–parallel systems. The optimal loading is aimed at achieving the greatest possible expected system performance subject to repair resource constraint. The model takes into account the dependence of elements’ failure rates on their load. The optimization algorithm uses a universal generating function technique for evaluating the expected

  19. Summary of Chancellor Denton's Academic Career Achievements

    E-print Network

    Agogino, Alice M.

    1 Summary of Chancellor Denton's Academic Career Achievements Chancellor Denice D. Denton exemplified the ideal academic, with strengths in all areas of academic achievement: disciplinary research Academic Senate I am honored to present a tribute to Chancellor Denton's academic accomplishments. I have

  20. Subgroup Achievement and Gap Trends: Ohio, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Ohio for 2010. In grade 8 math (the only grade in which subgroup trends were analyzed by achievement level), Ohio showed a clear trend of gains for all major subgroups at the basic-and-above, proficient-and-above, and advanced levels, with one exception. In grade 8 reading,…

  1. Reading Achievement, Birth Order and Family Size.

    ERIC Educational Resources Information Center

    Hatzitheologou, E.

    1997-01-01

    Examined the relationship between reading achievement and birth order in 503 Greek children. Found that birth order was not related to vocabulary knowledge or reading comprehension at second grade, but total reading achievement and reading comprehension were higher for first- and second-born sixth graders than for later-born sixth graders. (KB)

  2. Subgroup Achievement and Gap Trends: Maryland, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Maryland for 2010. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Maryland had data for racial/ethnic subgroups, low income students, and boys and girls at the proficient and advanced levels. The percentage of students reaching the…

  3. NATIONAL PLAN TO ACHIEVE MARITIME DOMAIN AWARENESS

    E-print Network

    Acton, Scott

    NATIONAL PLAN TO ACHIEVE MARITIME DOMAIN AWARENESS FOR THE NATIONAL STRATEGY FOR MARITIME SECURITY OCTOBER 2005 #12;National Strategy for Maritime Security: National Plan to Achieve Maritime Domain Directive-13 (NSPD-41/HSPD-13) (Maritime Security Policy, December 21, 2004) President Bush underscored

  4. Stability and Change in Achievement Goals

    ERIC Educational Resources Information Center

    Fryer, James W.; Elliot, Andrew J.

    2007-01-01

    The present research examined the nature of stability and change in achievement goal endorsement over time, using 4 complementary data-analytic approaches (differential continuity, mean-level change, individual-level change, and ipsative continuity). Three longitudinal studies were conducted in college classrooms; in each study, achievement goals…

  5. Vicarious and Direct Achievement Patterns in Adulthood

    ERIC Educational Resources Information Center

    Lipman-Blumen, Jean; Leavitt, Harold J.

    1976-01-01

    This paper presents a typology of direct and vicarious achievement orientations relevant to adult problems. Direct and vicarious achievement patterns are related to sex role socialization and sex-linked occupational choice. Recommendations are developed for reevaluating and redesigning adult occupational and interpersonal roles which would take…

  6. Attitudes and Achievement of Bruneian Science Students.

    ERIC Educational Resources Information Center

    Dhindsa, Harkirat S.; Chung, Gilbert

    2003-01-01

    Evaluates attitudes towards and achievement in science of Form 3 students studying in single-sex and coeducational schools in Brunei. Results demonstrated significant differences in attitudes towards and achievement in science of male and female students in single-sex schools and students in coeducational schools. (Contains 46 references.)…

  7. Family and Community Involvement: Achievement Effects

    Microsoft Academic Search

    Joyce L. Epstein; Mavis G. Sanders; Steven B. Sheldon

    The No Child Left Behind Act (NCLBA) requires schools to help every student achieve a high level of proficiency in math, reading, and science by 2014. It also requires districts and schools to involve families in ways that will boost student achievement. Yet, most districts and schools are struggling with how to implement effective partnership programs and how to measure

  8. Correlates of Achievement in an IPI School.

    ERIC Educational Resources Information Center

    Rookey, T. Jerome

    An attempt was made to determine what factors relate to achievement in language arts, mathematics, and certain attitudes in an individualized programmed instruction school. A total of 87 fifth grade pupils were tested both in the Fall and Spring using the Commonwealth of Pennsylvania's Pennsylvania Questionnaire and the Stanford Achievement Test.…

  9. Relationships among Piagetian, IQ, and Achievement Assessments.

    ERIC Educational Resources Information Center

    DeVries, Rheta

    Relationships between school achievement and two theoretically different measures of intelligence, Piagetian and psychometric, are explored in 143 bright, average, and retarded elementary school students. Factor analyses of the California Test of Mental Maturity, the Metropolitan Achievement Test, the Stanford-Binet, and fifteen Piaget-type tasks…

  10. Academic Motivation and Achievement among Urban Adolescents

    ERIC Educational Resources Information Center

    Long, Joyce F.; Monoi, Shinichi; Harper, Brian; Knoblauch, Dee; Murphy, P. Karen

    2007-01-01

    Although researchers report that motivational variables, such as interest and self-efficacy, positively relate to forms of achievement (e.g., standardized test scores, grades, number of problems solved correctly), other studies indicate that motivation's contribution to achievement is not consistent. Fewer studies, however, have examined these…

  11. Teacher Evaluation Practices and Student Achievement

    ERIC Educational Resources Information Center

    Lyon, Lucy Kay

    2010-01-01

    Extensive research has been conducted on improving student academic achievement and techniques to improve student learning. There has been little research that addresses the relationship between student achievement and teacher performance. The purpose of this study was to determine the relationship between performance-based teacher evaluation…

  12. Subgroup Achievement and Gap Trends: New York

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), New York showed a clear trend of gains in reading and math at the basic-and-above, proficient-and-above, and advanced levels for all major subgroups with just a few exceptions. Achievement gaps in reading and math also narrowed at grades 4 and 8 for most…

  13. Program for Area Concentration Achievement Testing.

    ERIC Educational Resources Information Center

    Golden, Anthony J.

    The Program for Area Concentration Achievement Testing (PACAT) produces the cooperative assessment instrument known as the Area Concentration Achievement Test (ACAT). The ACAT uses a model designed specifically to measure curricular strengths and weaknesses and to provide this information at the departmental level. PACAT has developed 57…

  14. Black Students: Psychosocial Issues and Academic Achievement.

    ERIC Educational Resources Information Center

    Berry, Gordon LaVern, Ed.; Asamen, Joy Keiko, Ed.

    This collection examines the history and current status of the economic, political, social, and psychological factors that influence the academic achievement of low-income African Americans. The introduction, "Afro-American Students and Academic Achievement" (J. K. Asamen), outlines the historical development of black education and previews the…

  15. Subgroup Achievement and Gap Trends: New Mexico

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), New Mexico showed across-the-board gains--improvements in reading and math at the basic-and-above, proficient-and-above, and advanced levels for all major racial/ethnic subgroups and low-income students. Progress in narrowing achievement gaps at grades 4, 8,…

  16. Academic Achievement Survey and Educational Assessment Research

    ERIC Educational Resources Information Center

    Tanaka, Koji

    2009-01-01

    The recent "Nationwide academic achievement and study situation survey" was clearly influenced by the idea of "authentic assessment", an educational assessment perspective focused on "quality" and "engagement". However, when "performance assessment", the assessment method corresponding to this focus, is adopted in academic achievement surveys, it…

  17. Subgroup Achievement and Gap Trends: Rhode Island

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Rhode Island showed gains--improvements in reading and math at the basic, proficient, and advanced levels for most racial/ethnic subgroups, low-income students, and boys and girls. Achievement gaps between students narrowed in most cases at grades 4 and 8.…

  18. Subgroup Achievement and Gap Trends: Rhode Island

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This year the Center on Education Policy analyzed data on the achievement of different groups of students in two distinct ways. First, it looked at grade 4 test results to determine whether the performance of various groups improved at three achievement levels--basic and above, proficient and above, and advanced. Second, it looked at gaps between…

  19. Subgroup Achievement and Gap Trends: Wisconsin, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Wisconsin for 2010. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Wisconsin showed across-the-board gains--improvements in reading and math at the basic-and-above, proficient-and-above, and advanced levels for all racial/ethnic…

  20. A Better Way to Motivate Achievement

    ERIC Educational Resources Information Center

    Parker, Dennis

    2012-01-01

    Many low income, minority schools in California are within 100 points of closing the achievement gap, a prize worth working for no matter how inconvenient, uncomfortable, or risky. In this article, the author describes a better way to motivate educators to try new things that will accelerate student learning and close the achievement gap. The…