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1

Regulating thrombus growth and stability to achieve an optimal response to injury.  

PubMed

An optimal platelet response to injury can be defined as one in which blood loss is restrained and haemostasis is achieved without the penalty of further tissue damage caused by unwarranted vascular occlusion. This brief review considers some of the ways in which thrombus growth and stability can be regulated so that an optimal platelet response can be achieved in vivo. Three related topics are considered. The first focuses on intracellular mechanisms that regulate the early events of platelet activation downstream of G protein coupled receptors for agonists such as thrombin, thromboxane A(2) and ADP. The second considers the ways in which signalling events that are dependent on stable contacts between platelets can influence the state of platelet activation and thus affect thrombus growth and stability. The third focuses on the changes that are experienced by platelets as they move from their normal environment in freely-flowing plasma to a very different environment within the growing haemostatic plug, an environment in which the narrowing gaps and junctions between platelets not only facilitate communication, but also increasingly limit both the penetration of plasma and the exodus of platelet-derived bioactive molecules. PMID:21781243

Brass, L F; Wannemacher, K M; Ma, P; Stalker, T J

2011-07-01

2

On achieving optimal throughput with network coding  

Microsoft Academic Search

With the constraints of network topologies and link capacities, achieving the optimal end-to-end throughput in data networks has been known as a fundamental but computationally hard problem. In this paper, we seek efficient solutions to the problem of achieving optimal throughput in data networks, with single or multiple unicast, multicast and broadcast sessions. Although previous approaches lead to solving NP-complete

Zongpeng Li; Baochun Li; Dan Jiang; Lap Chi Lau

2005-01-01

3

Mathematics Coursework Regulates Growth in Mathematics Achievement  

ERIC Educational Resources Information Center

Using data from the Longitudinal Study of American Youth (LSAY), we examined the extent to which students' mathematics coursework regulates (influences) the rate of growth in mathematics achievement during middle and high school. Graphical analysis showed that students who started middle school with higher achievement took individual mathematics…

Ma, Xin; Wilkins, Jesse L. M.

2007-01-01

4

LIFO-Backpressure Achieves Near Optimal Utility-Delay Tradeoff  

E-print Network

1 LIFO-Backpressure Achieves Near Optimal Utility-Delay Tradeoff Longbo Huang , Scott Moeller. In this paper, we show that the Backpressure algorithm, when combined with the LIFO queueing discipline (called LIFO-Backpressure), is able to achieve a utility that is within O(1/V ) of the optimal value, for any

Neely, Michael J.

5

Academic Optimism of Schools: A Force for Student Achievement  

ERIC Educational Resources Information Center

Researchers have been challenged to go beyond socioeconomic status in the search for school-level characteristics that make a difference in student achievement. The purpose of the present study was to identify a new construct, academic optimism, and then use it to explain student achievement while controlling for socioeconomic status, previous…

Hoy, Wayne K.; Tarter, John C.; Hoy, Anita Woolfolk

2006-01-01

6

The Effects of Academic Optimism on Elementary Reading Achievement  

ERIC Educational Resources Information Center

Purpose: The purpose of this paper is to explore the relationship between academic optimism (AO) and elementary reading achievement (RA). Design/methodology/approach: Using correlation and hierarchical linear regression, the authors examined school-level effects of AO on fifth grade reading achievement in 29 elementary schools in Alabama.…

Bevel, Raymona K.; Mitchell, Roxanne M.

2012-01-01

7

Insurance and Optimal Growth Frdric Gannon  

E-print Network

Insurance and Optimal Growth Frédéric Gannon (Université du Havre and EconomiX, France) Vincent connection be- tween insurance and economic growth. We develop a simple model to insert microeconomically founded optimal insurance with moral haz- ard in a standard macroeconomic framework of optimal growth. We

Paris-Sud XI, Université de

8

Parent involvement and science achievement: A latent growth curve analysis  

NASA Astrophysics Data System (ADS)

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 kindergarten class in 1998--1999. The present study's sample (N = 8,070) was based on students that had a sampling weight available from the public-use data file. Students were assessed in science achievement at third, fifth, and eighth grades and parents of the students were surveyed at the same time points. Analyses using latent growth curve modeling with time invariant and varying covariates in an SEM framework revealed a positive relationship between science achievement and parent involvement at eighth grade. Furthermore, there were gender and racial/ethnic differences in parents' school involvement as a predictor of science achievement. Findings indicated that students with lower initial science achievement scores had a faster rate of growth across time. The achievement gap between low and high achievers in earth, space and life sciences lessened from elementary to middle school. Parents' involvement with school usually tapers off after elementary school, but due to parent school involvement being a significant predictor of eighth grade science achievement, later school involvement may need to be supported and better implemented in secondary schooling.

Johnson, Ursula Yvette

9

PROC. WIOPT 2011. 1 LIFO-Backpressure Achieves Near Optimal  

E-print Network

PROC. WIOPT 2011. 1 LIFO-Backpressure Achieves Near Optimal Utility-Delay Tradeoff Longbo Huang work developing a new stochastic network utility maximization framework using Backpressure algorithms that are also delay efficient. In this paper, we show that the Backpressure algorithm, when combined

Huang, Longbo

10

Academic Optimism and Student Achievement in Urban Elementary Schools  

ERIC Educational Resources Information Center

Purpose: The aim of this study was two-fold: to demonstrate a general construct of schools called academic optimism and to show it was related to student achievement in urban elementary schools, even controlling for socioeconomic factors, and school size. Design/methodology/approach: Data were collected from 99 urban elementary schools in Texas…

Smith, Page A.; Hoy, Wayne K.

2007-01-01

11

LIFO-Backpressure Achieves Near Optimal Utility-Delay Tradeoff  

E-print Network

There has been considerable recent work developing a new stochastic network utility maximization framework using Backpressure algorithms, also known as MaxWeight. A key open problem has been the development of utility-optimal algorithms that are also delay efficient. In this paper, we show that the Backpressure algorithm, when combined with the LIFO queueing discipline (called LIFO-Backpressure), is able to achieve a utility that is within $O(1/V)$ of the optimal value, while maintaining an average delay of $O([\\log(V)]^2)$ for all but a tiny fraction of the network traffic. This result holds for general stochastic network optimization problems and general Markovian dynamics. Remarkably, the performance of LIFO-Backpressure can be achieved by simply changing the queueing discipline; it requires no other modifications of the original Backpressure algorithm. We validate the results through empirical measurements from a sensor network testbed, which show good match between theory and practice.

Huang, Longbo; Neely, Michael J; Krishnamachari, Bhaskar

2010-01-01

12

Postinfancy growth, schooling, and cognitive achievement: Young Lives1234  

PubMed Central

Background: Early life growth failure and resulting cognitive deficits are often assumed to be very difficult to reverse after infancy. Objective: We used data from Young Lives, which is an observational cohort of 8062 children in Ethiopia, India, Peru, and Vietnam, to determine whether changes in growth after infancy are associated with schooling and cognitive achievement at age 8 y. Design: We represented the growth by height-for-age z score at 1 y [HAZ(1)] and height-for-age z score at 8 y that was not predicted by the HAZ(1). We also characterized growth as recovered (stunted at age 1 y and not at age 8 y), faltered (not stunted at age 1 y and stunted at age 8 y), persistently stunted (stunted at ages 1 and 8 y), or never stunted (not stunted at ages 1 and 8 y). Outcome measures were assessed at age 8 y. Results: The HAZ(1) was inversely associated with overage for grade and positively associated with mathematics achievement, reading comprehension, and receptive vocabulary. Unpredicted growth from 1 to 8 y of age was also inversely associated with overage for grade (OR range across countries: 0.80–0.84) and positively associated with mathematics achievement (effect-size range: 0.05–0.10), reading comprehension (0.02–0.10), and receptive vocabulary (0.04–0.08). Children who recovered in linear growth had better outcomes than did children who were persistently stunted but were not generally different from children who experienced growth faltering. Conclusions: Improvements in child growth after early faltering might have significant benefits on schooling and cognitive achievement. Hence, although early interventions remain critical, interventions to improve the nutrition of preprimary and early primary school–age children also merit consideration. PMID:24067665

Schott, Whitney; Cueto, Santiago; Dearden, Kirk A; Engle, Patrice; Georgiadis, Andreas; Lundeen, Elizabeth A; Penny, Mary E; Stein, Aryeh D; Behrman, Jere R

2013-01-01

13

LIFO-Backpressure achieves near optimal utility-delay tradeoff  

Microsoft Academic Search

There has been considerable recent work developing a new stochastic network utility maximization framework using Backpressure algorithms, also known as MaxWeight. A key open problem has been the development of utility-optimal algorithms that are also delay efficient. In this paper, we show that the Backpressure algorithm, when combined with the LIFO queueing discipline (called LIFO-Backpressure), is able to achieve a

Longbo Huang; Scott Moeller; Michael J. Neely; Bhaskar Krishnamachari

2011-01-01

14

LIFO-Backpressure Achieves Near Optimal Utility-Delay Tradeoff  

Microsoft Academic Search

There has been considerable recent work developing a new stochastic network utility maximization framework using Backpressure algorithms, also known as MaxWeight. A key open problem has been the development of utility-optimal algorithms that are also delay efficient. In this paper, we show that the Backpressure algorithm, when combined with the LIFO queueing discipline (called LIFO-Backpressure), is able to achieve a

Longbo Huang; Scott Moeller; Michael J. Neely; Bhaskar Krishnamachari

2010-01-01

15

Optimized Delivery System Achieves Enhanced Endomyocardial Stem Cell Retention  

PubMed Central

Background Regenerative cell-based therapies are associated with limited myocardial retention of delivered stem cells. The objective of this study is to develop an endocardial delivery system for enhanced cell retention. Methods and Results Stem cell retention was simulated in silico using one and three-dimensional models of tissue distortion and compliance associated with delivery. Needle designs, predicted to be optimal, were accordingly engineered using nitinol – a nickel and titanium alloy displaying shape memory and super-elasticity. Biocompatibility was tested with human mesenchymal stem cells. Experimental validation was performed with species-matched cells directly delivered into Langendorff-perfused porcine hearts or administered percutaneously into the endocardium of infarcted pigs. Cell retention was quantified by flow cytometry and real time quantitative polymerase chain reaction methodology. Models, computing optimal distribution of distortion calibrated to favor tissue compliance, predicted that a 75°-curved needle featuring small-to-large graded side holes would ensure the highest cell retention profile. In isolated hearts, the nitinol curved needle catheter (C-Cath) design ensured 3-fold superior stem cell retention compared to a standard needle. In the setting of chronic infarction, percutaneous delivery of stem cells with C-Cath yielded a 37.7±7.1% versus 10.0±2.8% retention achieved with a traditional needle, without impact on biocompatibility or safety. Conclusions Modeling guided development of a nitinol-based curved needle delivery system with incremental side holes achieved enhanced myocardial stem cell retention. PMID:24326777

Behfar, Atta; Latere, Jean-Pierre; Bartunek, Jozef; Homsy, Christian; Daro, Dorothee; Crespo-Diaz, Ruben J.; Stalboerger, Paul G.; Steenwinckel, Valerie; Seron, Aymeric; Redfield, Margaret M.; Terzic, Andre

2014-01-01

16

Adaptation to Optimal Cell Growth through Self-Organized Criticality Chikara Furusawa  

E-print Network

that recursive cellular reproduction with opti- mal growth is achieved by controlling the flow rate is studied to show that cellular states are self-organized in a critical state for achieving optimal growth of cellular growth to reach a critical state depends only on the extent of environmental changes, while all

Kaneko, Kunihiko

17

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

PubMed Central

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

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

2013-01-01

18

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

ERIC Educational Resources Information Center

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…

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

2014-01-01

19

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

E-print Network

· Applying thermodynamics constraints to the model achieves higher growth rates and flux efficiency RHA1 that Accounts for Thermodynamics Constraints Timothy Cheung, Mohammad Tajparast, Dominic Frigon Optimize: Z=c.v Subject to: Flux Balance and i vi i Flux Balance Analysis (FBA) Thermodynamics

Barthelat, Francois

20

The optimal polarizations for achieving maximum contrast in radar images  

NASA Technical Reports Server (NTRS)

There is considerable interest in determining the optimal polarizations that maximize contrast between two scattering classes in polarimetric radar images. A systematic approach is presented for obtaining the optimal polarimetric matched filter, i.e., that filter which produces maximum contrast between two scattering classes. The maximization procedure involves solving an eigenvalue problem where the eigenvector corresponding to the maximum contrast ratio is an optimal polarimetric matched filter. To exhibit the physical significance of this filter, it is transformed into its associated transmitting and receiving polarization states, written in terms of horizontal and vertical vector components. For the special case where the transmitting polarization is fixed, the receiving polarization which maximizes the contrast ratio is also obtained. Polarimetric filtering is then applies to synthetic aperture radar images obtained from the Jet Propulsion Laboratory. It is shown, both numerically and through the use of radar imagery, that maximum image contrast can be realized when data is processed with the optimal polarimeter matched filter.

Swartz, A. A.; Yueh, H. A.; Kong, J. A.; Novak, L. M.; Shin, R. T.

1988-01-01

21

Achievement Gaps: An Examination of Differences in Student Achievement and Growth. The Full Report  

ERIC Educational Resources Information Center

The difference between the academic performance of poor students and wealthier students and between minority students and their non-minority peers is commonly known as the achievement gap. The current study examines the achievement gap using a large sample of students from a wide variety of school districts across the United States. It examines…

McCall, Martha S.; Hauser, Carl; Cronin, John; Kingsbury, G. Gage; Houser, Ronald

2006-01-01

22

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

Microsoft Academic Search

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

Xitao Fan

2001-01-01

23

Uncertain climate thresholds and optimal economic growth  

Microsoft Academic Search

We explore the combined effects of a climate threshold (a potential ocean thermohaline circulation collapse), parameter uncertainty, and learning in an optimal economic growth model. Our analysis shows that significantly reducing carbon dioxide ðCO2Þ emissions may be justified to avoid or delay even small (and arguably realistic) damages from an uncertain and irreversible climate change—even when future learning about the

Klaus Keller; Benjamin M. Bolker; David F. Bradfordc

2003-01-01

24

IEEE/ACM TRANS. ON NETWORKING, TO APPEAR 1 LIFO-Backpressure Achieves Near Optimal  

E-print Network

IEEE/ACM TRANS. ON NETWORKING, TO APPEAR 1 LIFO-Backpressure Achieves Near Optimal Utility-optimal algorithms that are also delay efficient. In this paper, we show that the Backpressure algorithm, when combined with the LIFO queueing discipline (called LIFO-Backpressure), is able to achieve a utility

Huang, Longbo

25

Aircraft optimization by a system approach: Achievements and trends  

NASA Technical Reports Server (NTRS)

Recently emerging methodology for optimal design of aircraft treated as a system of interacting physical phenomena and parts is examined. The methodology is found to coalesce into methods for hierarchic, non-hierarchic, and hybrid systems all dependent on sensitivity analysis. A separate category of methods has also evolved independent of sensitivity analysis, hence suitable for discrete problems. References and numerical applications are cited. Massively parallel computer processing is seen as enabling technology for practical implementation of the methodology.

Sobieszczanski-Sobieski, Jaroslaw

1992-01-01

26

Multidisciplinary optimization for engineering systems: Achievements and potential  

NASA Technical Reports Server (NTRS)

The currently common sequential design process for engineering systems is likely to lead to suboptimal designs. Recently developed decomposition methods offer an alternative for coming closer to optimum by breaking the large task of system optimization into smaller, concurrently executed and, yet, coupled tasks, identified with engineering disciplines or subsystems. The hierarchic and non-hierarchic decompositions are discussed and illustrated by examples. An organization of a design process centered on the non-hierarchic decomposition is proposed.

Sobieszczanski-Sobieski, Jaroslaw

1989-01-01

27

Achieving Optimal Privacy in Trust-Aware Social Recommender Systems  

NASA Astrophysics Data System (ADS)

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.

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

28

The Impact of Linking Distinct Achievement Test Scores on the Interpretation of Student Growth in Achievement  

ERIC Educational Resources Information Center

Changes to state tests impact the ability of State Education Agencies (SEAs) to monitor change in performance over time. The purpose of this study was to evaluate the Standardized Performance Growth Index (PGIz), a proposed statistical model for measuring change in student and school performance, across transitions in tests. The PGIz is a…

Airola, Denise Tobin

2011-01-01

29

Reading and Math Achievement Profiles and Longitudinal Growth Trajectories of Children with an Autism Spectrum Disorder  

ERIC Educational Resources Information Center

This study examined the reading and math achievement profiles and longitudinal growth trajectories of a nationally representative sample of children ages 6 through 9 with an autism spectrum disorder. Four distinct achievement profiles were identified: higher-achieving (39%), hyperlexia (9%), hypercalculia (20%) and lower-achieving (32%). Children…

Wei, Xin; Christiano, Elizabeth R. A.; Yu, Jennifer W.; Wagner, Mary; Spiker, Donna

2015-01-01

30

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

PubMed

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

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

2015-02-01

31

Exploring Gains in Reading and Mathematics Achievement among Regular and Exceptional Students Using Growth Curve Modeling  

ERIC Educational Resources Information Center

Using four-wave longitudinal reading and mathematics data (4th to 7th grades) from a large urban school district, growth curve modeling was used as a tool for examining three research questions: Are achievement gaps closing in reading and mathematics? What are the associations between prior-achievement and growth across the reading and mathematics…

Shin, Tacksoo; Davison, Mark L.; Long, Jeffrey D.; Chan, Chi-Keung; Heistad, David

2013-01-01

32

The Effects of Academic Optimism on Student Academic Achievement in Alabama  

ERIC Educational Resources Information Center

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…

Bevel, Raymona King

2010-01-01

33

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

ERIC Educational Resources Information Center

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…

Wu, Hsin-Chieh

2012-01-01

34

A tree-growth model to optimize silviculture Patrice Loisel  

E-print Network

the increase of its neighbors' growth, and cutting no tree limits individual growth. That shows how a forestA tree-growth model to optimize silviculture Patrice Loisel , Jean François Dhôte 2011 Abstract-aged forest. The model studied is a tree-growth model based on a system of two ordinary differential equations

Boyer, Edmond

35

Moderating Effects of Achievement Striving and Situational Optimism on the Relationship between Ability and Performance Outcomes of College Students.  

ERIC Educational Resources Information Center

Examined to what extent students' ability, achievement striving, and situational optimism influence performance outcomes and the interactive effects of ability and achievement striving, as well as ability and situational optimism, on student performance outcomes. Found that achievement striving and situational optimism may be as important as…

Nonis, Sarath A.; Wright, David

2003-01-01

36

Academic Achievement and Adolescent Drug Use: An Examination of Reciprocal Effects and Correlated Growth Trajectories  

ERIC Educational Resources Information Center

Background: The primary aim was to examine correlated growth trajectories and reciprocal effects between academic achievement and drug use over the course of junior high school. Methods: One hundred and three male and 98 female students from 3 rural junior high schools were surveyed 4 times over the course of 3 years. Dual trajectory latent growth

Henry, Kimberly L.

2010-01-01

37

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

ERIC Educational Resources Information Center

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…

Johnson, Ursula Y.; Hull, Darrell M.

2014-01-01

38

Reading and math achievement profiles and longitudinal growth trajectories of children with an autism spectrum disorder.  

PubMed

This study examined the reading and math achievement profiles and longitudinal growth trajectories of a nationally representative sample of children ages 6 through 9 with an autism spectrum disorder. Four distinct achievement profiles were identified: higher-achieving (39%), hyperlexia (9%), hypercalculia (20%) and lower-achieving (32%). Children with hypercalculia and lower-achieving profiles were more likely to be from low socioeconomic families and had lower functional cognitive skills than the higher-achieving profile. All four profiles lost ground in passage comprehension over time. Slower improvement occurred for the higher-achieving group on letter-word identification, the hyperlexia group on conversation abilities and the hypercalculia group on calculation and functional cognitive skills relative to the lower-achieving group. PMID:24449604

Wei, Xin; Christiano, Elizabeth Ra; Yu, Jennifer W; Wagner, Mary; Spiker, Donna

2015-02-01

39

Optimization of heating conditions during Cz BGO crystal growth  

NASA Astrophysics Data System (ADS)

We have studied the effect of geometrical and physical parameters of additional lower heater on thermal conditions during BGO growth by the Czochralski technique, in particular, on keeping flat melt/crystal interface during the whole growth process. Numerical simulation by CGSim software was used as an efficient tool for the analysis. After revealing optimal growth conditions and hot zone design by modeling, we have modified experimental growth setup and successfully improved crystal growth process in close agreement to modeling predictions.

Kolesnikov, A. V.; Galenin, E. P.; Sidletskiy, O. Ts.; Kalaev, V. V.

2014-12-01

40

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

PubMed Central

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

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

2014-01-01

41

Emergence of robust growth laws from optimal regulation of ribosome synthesis  

PubMed Central

Bacteria must constantly adapt their growth to changes in nutrient availability; yet despite large-scale changes in protein expression associated with sensing, adaptation, and processing different environmental nutrients, simple growth laws connect the ribosome abundance and the growth rate. Here, we investigate the origin of these growth laws by analyzing the features of ribosomal regulation that coordinate proteome-wide expression changes with cell growth in a variety of nutrient conditions in the model organism Escherichia coli. We identify supply-driven feedforward activation of ribosomal protein synthesis as the key regulatory motif maximizing amino acid flux, and autonomously guiding a cell to achieve optimal growth in different environments. The growth laws emerge naturally from the robust regulatory strategy underlying growth rate control, irrespective of the details of the molecular implementation. The study highlights the interplay between phenomenological modeling and molecular mechanisms in uncovering fundamental operating constraints, with implications for endogenous and synthetic design of microorganisms. PMID:25149558

Scott, Matthew; Klumpp, Stefan; Mateescu, Eduard M; Hwa, Terence

2014-01-01

42

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

ERIC Educational Resources Information Center

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…

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

2008-01-01

43

Abstract--Underactuated fingers have been extensively studied and optimized in order to achieve better grasp  

E-print Network

related to the coupling mechanisms between the fingers and their effects on grasp performance. This paper]. In this paper we describe how a simple friction-based mechanism can be applied to the transmission of cableAbstract--Underactuated fingers have been extensively studied and optimized in order to achieve

Dollar, Aaron M.

44

Academic Optimism of High School Teachers: Its Relationship to Organizational Citizenship Behaviors and Student Achievement  

ERIC Educational Resources Information Center

The purpose of this study is to build on an emergent research base for academic optimism by testing the construct and its relationship to student achievement and organizational citizenship behaviors in schools in a sample of public high schools. All participants in this study were full-time teachers, guidance counselors, and other full-time…

Wagner, Charles A.; DiPaola, Michael F.

2011-01-01

45

Relative importance of birth size and postnatal growth for women's educational achievement  

Microsoft Academic Search

Background: Child undernutrition, commonly measured by growth failure, is associated with functional disadvantages later in life. Aims: To assess relationships between child growth and women's educational achievement (EA). Study design and subjects: Women from four ladino Guatemalan villages were measured as children (1969–1977) and again at ages 20–29 years (1996–1999). The anthropometric measurements analyzed were weight, length, and head circumference

Haojie Li; Ann M. DiGirolamo; Huiman X. Barnhart; Aryeh D. Stein; Reynaldo Martorell

2004-01-01

46

Towards achieving a flattop crystal size distribution by continuous seeding and controlled growth  

E-print Network

Towards achieving a flattop crystal size distribution by continuous seeding and controlled growth a b s t r a c t A semi-continuous crystallizer configuration that combines continuous seeding using distribution is limited in industrial batch crystallizations, in which seed crystals are added near the start

Braatz, Richard D.

47

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

48

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

49

Optimization of a new mathematical model for bacterial growth  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objective of this research is to optimize a new mathematical equation as a primary model to describe the growth of bacteria under constant temperature conditions. An optimization algorithm was used in combination with a numerical (Runge-Kutta) method to solve the differential form of the new gr...

50

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

NASA Astrophysics Data System (ADS)

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.

Muller, Patricia Ann

51

Incorporating Student Mobility in Achievement Growth Modeling: A Cross-Classified Multiple Membership Growth Curve Model  

ERIC Educational Resources Information Center

Multiple membership random effects models (MMREMs) have been developed for use in situations where individuals are members of multiple higher level organizational units. Despite their availability and the frequency with which multiple membership structures are encountered, no studies have extended the MMREM approach to hierarchical growth curve…

Grady, Matthew W.; Beretvas, S. Natasha

2010-01-01

52

Commissioning, Operation, Real Time Monitoring and Evaluation of Pilot: Achieving Optimal Performance through Building Commissioning  

E-print Network

BUILDINGS ENERGY EFFICIENCY CONSORTIUM U.S. - CHINA CLEAN ENERGY RESEARCH CENTER (CERC-BEE) E3: Commissioning, Operation, Real Time Monitoring and Evaluation of Pilot Achieving Optimal Performance through Building Commissioning Xiufeng Pang... out the causes. • Provide technical support to demo projects to ensure that the CERC-BEE demonstrated technologies work properly and are integrated with the rest of the building systems • Review the Cx plans for the two demo projects, the CABR...

Pang,X.; Piette, M.A.; Hao,B.

2014-01-01

53

Cognitive predictors of achievement growth in mathematics: a 5-year longitudinal study.  

PubMed

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 intelligence and processing speed, and the central executive component of working memory predicted achievement or achievement growth in mathematics and, as a contrast domain, word reading. The phonological loop was uniquely predictive of word reading and the visuospatial sketch pad of mathematics. Early fluency in processing and manipulating numerical set size and Arabic numerals, accurate use of sophisticated counting procedures for solving addition problems, and accuracy in making placements on a mathematical number line were uniquely predictive of mathematics achievement. Use of memory-based processes to solve addition problems predicted mathematics and reading achievement but in different ways. The results identify the early quantitative competencies that uniquely contribute to mathematics learning. PMID:21942667

Geary, David C

2011-11-01

54

Optimal control analysis of the dynamic growth behavior of microorganisms.  

PubMed

Understanding the growth behavior of microorganisms using modeling and optimization techniques is an active area of research in the fields of biochemical engineering and systems biology. In this paper, we propose a general modeling framework, based on Monod model, to model the growth of microorganisms. Utilizing the general framework, we formulate an optimal control problem with the objective of maximizing a long-term cellular goal and solve it analytically under various constraints for the growth of microorganisms in a two substrate batch environment. We investigate the relation between long term and short term cellular goals and show that the objective of maximizing cellular concentration at a fixed final time is equivalent to maximization of instantaneous growth rate. We then establish the mathematical connection between the generalized framework and optimal and cybernetic modeling frameworks and derive generalized governing dynamic equations for optimal and cybernetic models. We finally illustrate the influence of various constraints in the cybernetic modeling framework on the optimal growth behavior of microorganisms by solving several dynamic optimization problems using genetic algorithms. PMID:25223235

Mandli, Aravinda R; Modak, Jayant M

2014-12-01

55

Preoperative treatment planning with intraoperative optimization can achieve consistent high-quality implants in prostate brachytherapy  

SciTech Connect

Advances in brachytherapy treatment planning systems have allowed the opportunity for brachytherapy to be planned intraoperatively as well as preoperatively. The relative advantages and disadvantages of each approach have been the subject of extensive debate, and some contend that the intraoperative approach is vital to the delivery of optimal therapy. The purpose of this study was to determine whether high-quality permanent prostate implants can be achieved consistently using a preoperative planning approach that allows for, but does not necessitate, intraoperative optimization. To achieve this purpose, we reviewed the records of 100 men with intermediate-risk prostate cancer who had been prospectively treated with brachytherapy monotherapy between 2006 and 2009 at our institution. All patients were treated with iodine-125 stranded seeds; the planned target dose was 145 Gy. Only 8 patients required adjustments to the plan on the basis of intraoperative findings. Consistency and quality were assessed by calculating the correlation coefficient between the planned and implanted amounts of radioactivity and by examining the mean values of the dosimetric parameters obtained on preoperative and 30 days postoperative treatment planning. The amount of radioactivity implanted was essentially identical to that planned (mean planned radioactivity, 41.27 U vs. mean delivered radioactivity, 41.36 U; R{sup 2} = 0.99). The mean planned and day 30 prostate V100 values were 99.9% and 98.6%, respectively. The mean planned and day 30 prostate D90 values were 186.3 and 185.1 Gy, respectively. Consistent, high-quality prostate brachytherapy treatment plans can be achieved using a preoperative planning approach, mostly without the need for intraoperative optimization. Good quality assurance measures during simulation, treatment planning, implantation, and postimplant evaluation are paramount for achieving a high level of quality and consistency.

Kudchadker, Rajat J., E-mail: rkudchad@mdanderson.org [Department of Radiation Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Pugh, Thomas J. [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Swanson, David A. [Department of Urology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Bruno, Teresa L.; Bolukbasi, Yasemin; Frank, Steven J. [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)

2012-01-01

56

Preoperative treatment planning with intraoperative optimization can achieve consistent high-quality implants in prostate brachytherapy.  

PubMed

Advances in brachytherapy treatment planning systems have allowed the opportunity for brachytherapy to be planned intraoperatively as well as preoperatively. The relative advantages and disadvantages of each approach have been the subject of extensive debate, and some contend that the intraoperative approach is vital to the delivery of optimal therapy. The purpose of this study was to determine whether high-quality permanent prostate implants can be achieved consistently using a preoperative planning approach that allows for, but does not necessitate, intraoperative optimization. To achieve this purpose, we reviewed the records of 100 men with intermediate-risk prostate cancer who had been prospectively treated with brachytherapy monotherapy between 2006 and 2009 at our institution. All patients were treated with iodine-125 stranded seeds; the planned target dose was 145 Gy. Only 8 patients required adjustments to the plan on the basis of intraoperative findings. Consistency and quality were assessed by calculating the correlation coefficient between the planned and implanted amounts of radioactivity and by examining the mean values of the dosimetric parameters obtained on preoperative and 30 days postoperative treatment planning. The amount of radioactivity implanted was essentially identical to that planned (mean planned radioactivity, 41.27 U vs. mean delivered radioactivity, 41.36 U; R(2) = 0.99). The mean planned and day 30 prostate V100 values were 99.9% and 98.6%, respectively. The mean planned and day 30 prostate D90 values were 186.3 and 185.1 Gy, respectively. Consistent, high-quality prostate brachytherapy treatment plans can be achieved using a preoperative planning approach, mostly without the need for intraoperative optimization. Good quality assurance measures during simulation, treatment planning, implantation, and postimplant evaluation are paramount for achieving a high level of quality and consistency. PMID:22560295

Kudchadker, Rajat J; Pugh, Thomas J; Swanson, David A; Bruno, Teresa L; Bolukbasi, Yasemin; Frank, Steven J

2012-01-01

57

On the Achievable Efficiency-Fairness Tradeoff in Utility-Optimal MAC Protocols  

NASA Astrophysics Data System (ADS)

We use the network utility maximization (NUM) framework to create an efficient and fair medium access control (MAC) protocol for wireless networks. By adjusting the parameters in the utility objective functions of NUM problems, we control the tradeoff between efficiency and fairness of radio resource allocation through a rigorous and systematic design. In this paper, we propose a scheduling-based MAC protocol. Since it provides an upper-bound on the achievable performance, it establishes the optimality benchmarks for comparison with other algorithms in related work.

Lee, Jang-Won; Chiang, Mung; Calderbank, A. Robert

58

Optimization of Dairy Sludge for Growth of Rhizobium Cells  

PubMed Central

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

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

2013-01-01

59

Optimal capacity in the Banking Sector and Economic Growth  

E-print Network

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

Paris-Sud XI, Université de

60

Predicting long-term growth in students' mathematics achievement: the unique contributions of motivation and cognitive strategies.  

PubMed

This research examined how motivation (perceived control, intrinsic motivation, and extrinsic motivation), cognitive learning strategies (deep and surface strategies), and intelligence jointly predict long-term growth in students' mathematics achievement over 5 years. Using longitudinal data from six annual waves (Grades 5 through 10; Mage  = 11.7 years at baseline; N = 3,530), latent growth curve modeling was employed to analyze growth in achievement. Results showed that the initial level of achievement was strongly related to intelligence, with motivation and cognitive strategies explaining additional variance. In contrast, intelligence had no relation with the growth of achievement over years, whereas motivation and learning strategies were predictors of growth. These findings highlight the importance of motivation and learning strategies in facilitating adolescents' development of mathematical competencies. PMID:23278807

Murayama, Kou; Pekrun, Reinhard; Lichtenfeld, Stephanie; Vom Hofe, Rudolf

2013-01-01

61

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

PubMed Central

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

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

2011-01-01

62

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

PubMed

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

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

2011-01-01

63

Birth Weight and Infant Growth: Optimal Infant Weight Gain versus Optimal Infant Weight  

Microsoft Academic Search

Objective: Infant growth assessment often focuses on “optimal” infant weights and lengths at specific ages, while de-emphasizing infant\\u000a weight gain. Objective of this study was to examine infant growth patterns by measuring infant weight gain relative to birth\\u000a weight. Methods: We conducted this study based on data collected in a prospective cohort study including 3,302 births with follow up examinations

Xu Xiong; Joan Wightkin; Jeanette H. Magnus; Gabriella Pridjian; Juan M. Acuna; Pierre Buekens

2007-01-01

64

Numerical Optimization of the Thermal Field in Bridgman Detached Growth  

NASA Technical Reports Server (NTRS)

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.

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

2009-01-01

65

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

PubMed

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

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

2014-04-01

66

Gender Differences in Growth in Mathematics Achievement: Three-Level Longitudinal and Multilevel Analyses of Individual, Home, and School Influences.  

ERIC Educational Resources Information Center

Focuses on gender differences in growth in mathematics achievement in relation to various social-psychological factors such as attitude towards mathematics, self-esteem, parents' academic encouragement, mathematics teachers' expectations, and peer influence. Results indicate that gender differences in growth in mathematics varied by the student's…

Ai, Xiaoxia

2002-01-01

67

Optimizing edible fungal growth and biodegradation of inedible crop residues using various cropping methods.  

PubMed

Long-term manned space flights to Mars require the development of an advanced life support (ALS) ecosystem including efficient food crop production, processing and recycling waste products thereof. Using edible white rot fungi (EWRF) to achieve effective biomass transformation in ALS requires optimal and rapid biodegradative activity on lignocellulosic wastes. We investigated the mycelial growth of Lentinula edodes and Pleurotus ostreatus on processed residues of various crops under various cropping patterns. In single cropping, mycelial growth and fruiting in all strains were significantly repressed on sweet potato and basil. However, growth of the strains was improved when sweet potato and basil residues were paired with rice or wheat straw. Oyster mushroom (Pleurotus) strains were better than shiitake (L. edodes) strains under single, paired, and mixed cropping patterns. Mixed cropping further eliminated the inherent inhibitory effect of sweet potato, basil, or lettuce on fungal growth. Co-cropping fungal species had a synergistic effect on rate of fungal growth, substrate colonization, and fruiting. Use of efficient cropping methods may enhance fungal growth, fruiting, biodegradation of crop residues, and efficiency of biomass recycling. PMID:18155518

Nyochembeng, Leopold M; Beyl, Caula A; Pacumbaba, R P

2008-09-01

68

Optimal conditions of mycelia growth of Laetiporus sulphureus sensu lato  

PubMed Central

Laetiporus sulphureus is an edible wood-rotting basidiomycete, growing on decaying logs, stumps, and trunks of many deciduous and coniferous tree species. This fungus produces relatively large striking yellowish or orange-coloured bracket-like fruitbodies. L. sulphureus is widely consumed as a nutritional food because of its fragrance and texture. In this study, two L. sulphureus strains, MFLUCC 12-0546 and MFLUCC 12-0547, isolated from Chiang Rai, Thailand, were investigated for optimal conditions of mycelia growth. Potato dextrose agar and malt extract agar were observed as the favourable medium for mycelia growth. The optimum pH and temperature for the mushroom mycelia were 6–8 and 25–30°C, respectively. PMID:25544934

Luangharn, Thatsanee; Karunarathna, Samantha C.; Hyde, Kevin D.; Chukeatirote, Ekachai

2014-01-01

69

Should Schools Be Optimistic? An Investigation of the Association between Academic Optimism of Schools and Student Achievement in Primary Education  

ERIC Educational Resources Information Center

Academic emphasis, collective efficacy, and faculty trust in students and parents (3 school characteristics positively associated with student achievement) are assumed to form a higher order latent construct, "academic optimism" (Hoy, Tarter, & Woolfolk Hoy, 2006a, 2006b). The aim of the present study is to corroborate the latent…

Boonen, Tinneke; Pinxten, Maarten; Van Damme, Jan; Onghena, Patrick

2014-01-01

70

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

ERIC Educational Resources Information Center

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…

Chang, I-Hua

2011-01-01

71

Robust Airfoil Optimization to Achieve Consistent Drag Reduction Over a Mach Range  

NASA Technical Reports Server (NTRS)

We prove mathematically that in order to avoid point-optimization at the sampled design points for multipoint airfoil optimization, the number of design points must be greater than the number of free-design variables. To overcome point-optimization at the sampled design points, a robust airfoil optimization method (called the profile optimization method) is developed and analyzed. This optimization method aims at a consistent drag reduction over a given Mach range and has three advantages: (a) it prevents severe degradation in the off-design performance by using a smart descent direction in each optimization iteration, (b) there is no random airfoil shape distortion for any iterate it generates, and (c) it allows a designer to make a trade-off between a truly optimized airfoil and the amount of computing time consumed. For illustration purposes, we use the profile optimization method to solve a lift-constrained drag minimization problem for 2-D airfoil in Euler flow with 20 free-design variables. A comparison with other airfoil optimization methods is also included.

Li, Wu; Huyse, Luc; Padula, Sharon; Bushnell, Dennis M. (Technical Monitor)

2001-01-01

72

Evaluating and optimizing horticultural regimes in space plant growth facilities  

NASA Technical Reports Server (NTRS)

In designing innovative space plant growth facilities (SPGF) for long duration space flight, various limitations must be addressed including onboard resources: volume, energy consumption, heat transfer and crew labor expenditure. The required accuracy in evaluating on board resources by using the equivalent mass methodology and applying it to the design of such facilities is not precise. This is due to the uncertainty of the structure and not completely understanding the properties of all associated hardware, including the technology in these systems. We present a simple criteria of optimization for horticultural regimes in SPGF: Qmax = max [M x (EBI)2/(V x E x T], where M is the crop harvest in terms of total dry biomass in the plant growth system; EBI is the edible biomass index (harvest index), V is volume occupied by the crop; E is the crop light energy supply during growth; T is the crop growth duration. The criterion reflects directly on the consumption of onboard resources for crop production. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

Berkovich, Y. A.; Chetirkin, P. V.; Wheeler, R. M.; Sager, J. C.

2004-01-01

73

Tumor Growth Prediction with Hyperelastic Biomechanical Model, Physiological Data Fusion, and Nonlinear Optimization  

PubMed Central

Tumor growth prediction is usually achieved by physiological modeling and model personalization from clinical measurements. Although image-based frameworks have been proposed with promising results, different issues such as infinitesimal strain assumption, complicated optimization procedures, and lack of functional information, may limit the prediction performance. Therefore, we propose a framework which comprises a hyperelastic biomechanical model for better physiological plausibility, gradient-free nonlinear optimization for more flexible choices of models and objective functions, and physiological data fusion of structural and functional images for better subject-specificity. Experiments were performed on synthetic and clinical data to verify parameter estimation capability and prediction performance of the framework. Comparisons of using different biomechanical models and objective functions were also performed. From the experimental results on eight patient data sets, the recall, precision, and relative volume difference (RVD) between predicted and measured tumor volumes are 84.85±6.15%, 87.08±7.83%, and 13.81±6.64% respectively. PMID:25485359

Wong, Ken C. L.; Summers, Ronald M.; Kebebew, Electron; Yao, Jianhua

2015-01-01

74

Growth and academic achievement in inner-city kindergarten children. The relationship of height, weight, cognitive ability, and neurodevelopmental level.  

PubMed

Measures of height, weight, nonverbal cognitive ability (Ravens progressive matrix), visual-motor-perceptual ability (Beery-Buktenica test of Visual Motor Integration [VMI]), the imitation-of-gestures technique, and academic achievement (Stanford Early Achievement) were obtained for a sample of 82 children from a poor inner-city community. In contrast to prior reports from the United States and about other developed countries, anthropometric measures were related both to academic achievement and to these measures of neurodevelopment. They were not consistently related to measures of nonverbal cognitive ability. Regression analyses revealed that general cognitive ability contributed more variance (39%) to predictions of achievement than all other variables, including weight for age (13%) and VMI (6%). Children with reduced somatic growth were likely to do poorly in school, but the data do not show that undernutrition causes learning failure. Rather, they suggest that environmental problems affecting the development of thought processes and nutrient intake precede both growth and learning failure. PMID:1628466

Karp, R; Martin, R; Sewell, T; Manni, J; Heller, A

1992-06-01

75

Academic Optimism and Collective Responsibility: An Organizational Model of the Dynamics of Student Achievement  

ERIC Educational Resources Information Center

This study was designed to examine the construct of academic optimism and its relationship with collective responsibility in a sample of Taiwan elementary schools. The construct of academic optimism was tested using confirmatory factor analysis, and the whole structural model was tested with a structural equation modeling analysis. The data were…

Wu, Jason H.

2013-01-01

76

Measuring Opportunity to Learn and Achievement Growth: Key Research Issues with Implications for the Effective Education of All Students  

ERIC Educational Resources Information Center

The related constructs of opportunity to learn (OTL) and achievement growth are fundamental aspects of the current large-scale assessment and accountability system in operation in the United States. For purposes of this article, OTL is defined as the degree to which a teacher dedicates instructional time and content coverage to the intended…

Elliott, Stephen N.

2015-01-01

77

Predicting Long-Term Growth in Students' Mathematics Achievement: The Unique Contributions of Motivation and Cognitive Strategies  

ERIC Educational Resources Information Center

This research examined how motivation (perceived control, intrinsic motivation, and extrinsic motivation), cognitive learning strategies (deep and surface strategies), and intelligence jointly predict long-term growth in students' mathematics achievement over 5 years. Using longitudinal data from six annual waves (Grades 5 through 10;…

Murayama, Kou; Pekrun, Reinhard; Lichtenfeld, Stephanie; vom Hofe, Rudolf

2013-01-01

78

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

PubMed Central

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

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

2013-01-01

79

High production in a herbaceous perennial plant achieved by continuous growth and synchronized population dynamics  

Microsoft Academic Search

Continuous changes in the population dynamics, above- and belowground biomass, growth rates, and production of the emergent rush Juncus effusus were evaluated over an annual period in a subtemperate riparian wetland. Extant and emerging individual photosynthetic culms (shoots) were labeled individually and their growth dynamics quantified in replicated plots. Lengths of living (chlorophyllous) portions and basal diameters of several thousand

Robert G Wetzel; Michael J Howe

1999-01-01

80

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

ERIC Educational Resources Information Center

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…

Riska, Patricia A.

2010-01-01

81

Growth and change in attention problems, disruptive behavior, and achievement from kindergarten to fifth grade.  

PubMed

Despite widespread interest in children's adjustment problems, existing research does not provide conclusive evidence regarding the direction of the associations of achievement with classroom attention problems and disruptive behavior over the course of elementary school. Using a nationally representative sample of 16,260 kindergarteners, this study examined the temporal sequence of achievement, classroom attention problems, and disruptive behavior, focusing on how changes in skills and problems unfold across key periods between kindergarten and fifth grade. Results indicate that improvements in attention during the earliest years of schooling predict achievement gains through third grade. However, changes in disruptive behavior do not predict subsequent changes in achievement. Evidence linking changes in achievement to changes in classroom attention problems and disruptive behavior was less consistent. These findings point to the need to develop and examine early interventions that can improve attention skills as a mechanism for improving children's academic trajectories in elementary school. PMID:25376191

Claessens, Amy; Dowsett, Chantelle

2014-12-01

82

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

NASA Astrophysics Data System (ADS)

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.

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

2006-12-01

83

On Achieving Fairness in the Allocation of Scarce Resources: Measurable Principles and Multiple Objective Optimization Approaches  

Microsoft Academic Search

Equity principles are embedded within a multiple objective framework for obtaining optimal solutions to a generic allocation problem, such as the fair distribution of water, energy, or other types of key resources among users in society. Because of the great import of fresh water as a scarce and diminishing resource within and among many nations of the world, the equity

Lizhong Wang; Liping Fang; Keith W. Hipel

2007-01-01

84

Study of optimal extraction conditions for achieving high yield and antioxidant activity of tomato seed oil  

Technology Transfer Automated Retrieval System (TEKTRAN)

Tomato seeds resulting from tomato processing by-product have not been effectively utilized as value-added products. This study investigated the kinetics of oil extraction from tomato seeds and sought to optimize the oil extraction conditions. The oil was extracted by using hexane as solvent for 0 t...

85

Optimal Experience and Reading Achievement in Virtual Environments among College Level Developmental Readers  

ERIC Educational Resources Information Center

In this mixed methods study the potential for developmental readers to experience optimal experience (flow) within the multi-user virtual environment, "Second Life," was examined. In an educational context, "Second Life" provided a space for constructivist learning, socialization, exploration, discovery and creativity. The communicative, social…

Burgess, Melissa L.

2010-01-01

86

Journal of Environmental Economics and Management 48 (2004) 723741 Uncertain climate thresholds and optimal economic growth  

E-print Network

thermohaline circulation collapse), parameter uncertainty, and learning in an optimal economic growth model; Climate thresholds; Abrupt climate change; North Atlantic thermohaline circulation; Optimal growth model thresholds such as a collapse of the ocean thermohaline circulation (e.g., [46,51]). In contrast, many

Keller, Klaus

87

Growth and the Optimal Carbon Tax: When to switch from exhaustible resources to renewables?  

Microsoft Academic Search

Optimal climate policy is studied in a Ramsey growth model. A developing economy weighs global warming less, hence is more likely to exhaust fossil fuel and exacerbate global warming. The optimal carbon tax is higher for a developed economy. We analyze the optimal time of transition from fossil fuel to renewables, amount of fossil fuel to leave in situ, and

Frederick van der Ploeg; Cees Withagen

2010-01-01

88

Growth and the Optimal Carbon Tax: When to Switch from Exhaustible Resources to Renewables?  

Microsoft Academic Search

Optimal climate policy is studied in a Ramsey growth model. A developing economy weighs global warming less, hence is more likely to exhaust fossil fuel and exacerbate global warming. The optimal carbon tax is higher for a developed economy. We analyze the optimal time of transition from fossil fuel to renewables, amount of fossil fuel to leave in situ, and

Frederick van der Ploeg; Cees Withagen

2011-01-01

89

Birth Weight, Math and Reading Achievement Growth: A Multilevel between-Sibling, between-Families Approach  

ERIC Educational Resources Information Center

We used multilevel covariance structure analysis to study the relationship between birth weight, family context and youth math and reading comprehension growth from approximately ages 5 through 14 within and between families. Using data from the National Longitudinal Survey of Youth Child Sample, we examined the relationship between birth weight…

Goosby, Bridget J.; Cheadle, Jacob E.

2009-01-01

90

A General Multivariate Latent Growth Model with Applications to Student Achievement  

ERIC Educational Resources Information Center

The evaluation of the formative process in the University system has been assuming an ever increasing importance in the European countries. Within this context, the analysis of student performance and capabilities plays a fundamental role. In this work, the authors propose a multivariate latent growth model for studying the performances of a…

Bianconcini, Silvia; Cagnone, Silvia

2012-01-01

91

Perceived Social Support and Academic Achievement: Cross-Lagged Panel and Bivariate Growth Curve Analyses  

ERIC Educational Resources Information Center

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…

Mackinnon, Sean P.

2012-01-01

92

Achieving high lipid productivity of a thermotolerant microalga Desmodesmus sp. F2 by optimizing environmental factors and nutrient conditions.  

PubMed

The optimal conditions for cultivating the thermotolerant lipid-rich microalga Desmodesmus sp. F2 to achieve maximal lipid productivity were determined in this study. The conditions were light intensity, 700?mol/m(2)s; temperature, 35°C; cultivation nitrogen source, nitrate; initial nitrogen level, 6.6mM nitrogen. Carbon dioxide (2.5%, 0.2 vvm) was pumped into the cultures continuously. In the pre-optimized conditions, the maximal lipid productivity of this microalga was 113mg/L/d, which was raised to 263mg/L/d in the optimized conditions. This level of lipid productivity of microalgae is the highest ever reported in the literature. Fatty acid composition of the lipid produced by Desmodesmus sp. F2 in the optimal conditions was determined, in which C16 and C18 species accounted for 95% of the fatty acids. Saturated, monounsaturated and polyunsaturated fatty acids accounted for 38.9%, 33.1% and 22.6%, respectively. Based on the analysis, this lipid quality makes it a good feedstock for biodiesel production. PMID:24491294

Ho, Shih-Hsin; Chang, Jo-Shu; Lai, Yen-Ying; Chen, Ching-Nen Nathan

2014-03-01

93

MOCVD optimized growth for laser diodes emitting at 980nm via photoluminescence  

NASA Astrophysics Data System (ADS)

We have investigated different growth conditions of AlGaAs and InGaAs quantum wells (QWs) by metal organic chemical vapor deposition (MOCVD) for applications in high-power laser diodes emitting at 980nm. According to different experimental results measured by Photoluminescence (PL), we optimized the growth conditions. Growth temperature, V/III ratio, growth interruption and spacer time have been studied in detail. We have found the optimal growth conditions for laser diodes emitting at 980nm grown by metal organic chemical vapor deposition (MOCVD). As for our experiments, the best suitable growth temperature of AlGaAs and InGaAs QWs was 700°C and 600°C, respectively. The growth procedure of laser diodes should include growth interruption and spacer layers surrounding QWs. V/III ratio was about 130 during the growth of QWs.

Li, Jianjun; He, Linjie; Lin, Shengjie; Han, Jun; Deng, Jun

2014-07-01

94

Health resource variability in the achievement of optimal performance and clinical outcome in ischemic heart disease.  

PubMed

A disparity between evidence and practice in the management of ischemic heart disease is frequently observed. Guideline adherence and clinical outcomes are influenced by system, provider, and patient factors. Recently, performance improvement measures for cardiovascular disease have gained a lot of popularity worldwide. These measures may facilitate the uptake of evidence-based recommendations and improve patient outcomes. While apparently valid as quality metrics, their impacts on clinical outcomes remain limited and are areas of further research. Several methods for optimizing performance have been instituted and essentially involve three different approaches-improvement in the reporting of data on guideline adherence, providing infrastructure and tools, and providing incentives to improve guideline adherence. Public reporting of quality metrics and "pay-for-performance" are some novel performance improvement tools. The impact of these approaches on patient outcomes will be pivotal in improving cardiovascular outcomes in the future. PMID:25612925

Sardar, Partha; Kundu, Amartya; Nairooz, Ramez; Chatterjee, Saurav; Ledley, Gary S; Aronow, Wilbert S

2015-02-01

95

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

PubMed

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

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

2014-11-01

96

Quantitative analysis in the characterization and optimization of protein crystal growth.  

PubMed

Protein crystal growth often depends on the combination of many different factors. Some affect protein solubility directly; others may act indirectly by causing conformational changes. Systematic characterization of these factors can be important for generating good crystals. It can also provide useful insight into the biochemical behavior of the protein being crystallized. Here we focus on statistical methods to achieve these two objectives. (1) Characterization of a protein system by analyzing patterns of crystal polymorphism under different levels of biochemical parameters, such as ligands and pH. Tests of the reproducibility of crystal growth experiments indicate that quantitative scales of crystal quality can be statistically significant. Analysis of variance for a replicated, full-factorial design in which four factors were tested at two levels has been used to demonstrate highly significant, biochemically relevant, two-factor interactions strongly implicating pH and ligand-dependent conformational changes. (2) Optimization of crystal growth via response-surface methods. 'Minimum predicted variance' designs provide for efficient response-surface experiments aimed at constructing quadratic models in several dimensions. We have used such models to improve crystal size and quality significantly for three forms of Bacillus stearothermophilus tryptophanyl-tRNA synthetase. In one case we can now avoid having to increase the size by repeated seeding, a difficult procedure that also produces unwanted growth of satellite crystals. Graphs of two-dimensional level surfaces reveal a number of ridges, where the same result is obtained for many combinations of the factors usually varied when trying to improve crystals. An important inference is that it may be better to sample simultaneously for the effects of protein concentration and supersaturation. For a system involving only one crystallizing agent, supersaturation can be approximated as the product of protein and precipitant concentrations. Use of this search direction significantly improves the performance of response-surface experiments. Advantages of growing crystals at stationary points of their response surfaces include better crystals and higher reproducibility, since crystal growth at stationary points is insulated from the deleterious effects of experimental fluctuations. This arises because the derivatives of the response are by definition zero with respect to the experimental variables. Quantitative analysis of appropriately designed crystal growth experiments can thus be a powerful way to characterize complex and interacting biochemical dependencies in macromolecular systems and optimize parameters important to the crystallography. PMID:15299421

Carter, C W; Yin, Y

1994-07-01

97

Perceived Social Support and Academic Achievement: Cross-Lagged Panel and Bivariate Growth Curve Analyses  

Microsoft Academic Search

As students transition to post-secondary education, they experience considerable stress and declines in academic performance.\\u000a Perceived social support is thought to improve academic achievement by reducing stress. Longitudinal designs with three or\\u000a more waves are needed in this area because they permit stronger causal inferences and help disentangle the direction of relationships.\\u000a This study uses a cross-lagged panel and a

Sean P. Mackinnon

98

Studying the Relationship between Children's Self-Control and Academic Achievement: An Application of Second-Order Growth Curve Model Analysis.  

ERIC Educational Resources Information Center

The functional relationships between developmental change in children's self-control and academic achievement were examined using longitudinal family data. Multivariate latent growth models (LGM) were specified to determine whether the rate of growth in academic achievement changes as a function of developmental change in self-control. Data came…

Kim, Sooyeon; Murry, Velma McBride; Brody, Gene H.

99

Mapped weighted essentially non-oscillatory schemes: Achieving optimal order near critical points  

NASA Astrophysics Data System (ADS)

In this paper, a new fifth-order weighted essentially non-oscillatory scheme is developed. Necessary and sufficient conditions on the weights for fifth-order convergence are derived; one more condition than previously published is found. A detailed analysis reveals that the version of this scheme implemented by Jiang and Shu [G.-S. Jiang, C.-W. Shu, Efficient implementation of weighted ENO schemes, J. Comput. Phys. 126 (1996) 202-228] is, in general, only third-order accurate at critical points. This result is verified in a simple example. The magnitude of ?, a parameter which keeps the weights bounded, and the level of grid resolution are shown to determine the order of the scheme in a non-trivial way. A simple modification of the original scheme is found to be sufficient to give optimal order convergence even near critical points. This is demonstrated using the one-dimensional linear advection equation. Also, four examples utilizing the compressible Euler equations are used to demonstrate the scheme's improved behavior for practical shock capturing problems.

Henrick, Andrew K.; Aslam, Tariq D.; Powers, Joseph M.

2005-08-01

100

Oligodendrocyte progenitors balance growth with self-repulsion to achieve homeostasis in the adult brain  

PubMed Central

The adult CNS contains an abundant population of oligodendrocyte precursor cells (NG2+ cells) that generate oligodendrocytes and repair myelin, but how these ubiquitous progenitors maintain their density is unknown. Here we generated NG2-mEGFP mice and used in vivo two-photon imaging to study their dynamics in the adult brain. Time-lapse imaging revealed that NG2+ cells in the cortex are highly dynamic; they survey their local environment with motile filopodia, extend growth cones, and continuously migrate. They maintain unique territories through self-avoidance, and NG2+ cell loss through death, differentiation, or ablation triggered rapid migration and proliferation of adjacent cells to restore their density. NG2+ cells recruited to sites of focal CNS injury were similarly replaced by a proliferative burst surrounding the injury site. Thus, homeostatic control of NG2+ cell density through a balance of active growth and self-repulsion ensures that these progenitors are available to replace oligodendrocytes and participate in tissue repair. PMID:23624515

Hughes, E. G.; Kang, S. H.; Fukaya, M.; Bergles, D. E.

2013-01-01

101

Patterned growth of carbon nanotubes over vertically aligned silicon nanowire bundles for achieving uniform field emission  

PubMed Central

A fabrication strategy is proposed to enable precise coverage of as-grown carbon nanotube (CNT) mats atop vertically aligned silicon nanowire (VA-SiNW) bundles in order to realize a uniform bundle array of CNT-SiNW heterojunctions over a large sample area. No obvious electrical degradation of as-fabricated SiNWs is observed according to the measured current-voltage characteristic of a two-terminal single-nanowire device. Bundle arrangement of CNT-SiNW heterojunctions is optimized to relax the electrostatic screening effect and to maximize the field enhancement factor. As a result, superior field emission performance and relatively stable emission current over 12 h is obtained. A bright and uniform fluorescent radiation is observed from CNT-SiNW-based field emitters regardless of its bundle periodicity, verifying the existence of high-density and efficient field emitters on the proposed CNT-SiNW bundle arrays. PMID:25298758

2014-01-01

102

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

E-print Network

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 ...

Yang, Yung-Hun

103

Numerical optimization of Ignition and Growth reactive flow modeling for PAX2A  

NASA Astrophysics Data System (ADS)

Variable metric nonlinear optimization has been successfully applied to the parameterization of unreacted and reacted products thermodynamic equations of state and reactive flow modeling of the HMX based high explosive PAX2A. The NLQPEB nonlinear optimization program has been recently coupled to the LLNL developed two-dimensional high rate continuum modeling programs DYNA2D and CALE. The resulting program has the ability to optimize initial modeling parameters. This new optimization capability was used to optimally parameterize the Ignition and Growth reactive flow model to experimental manganin gauge records. The optimization varied the Ignition and Growth reaction rate model parameters in order to minimize the difference between the calculated pressure histories and the experimental pressure histories.

Baker, E. L.; Schimel, B.; Grantham, W. J.

1996-05-01

104

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

E-print Network

. Introduction Large solid-state lasers, such as the National Igni- tion Facility (NIF) [1] and OMEGA EP [2 in the laser beam line. A general meth- od for optimizing spot shadowing in large, solid-state lasers is usefulSpot-shadowing optimization to mitigate damage growth in a high-energy-laser amplifier chain Seung

Fienup, James R.

105

Optimal Ablation Volumes Are Achieved at Submaximal Power Settings in a 2.45-GHz Microwave Ablation System.  

PubMed

Introduction. Local ablative therapies, including microwave ablation (MWA), are common treatment modalities for in situ tumor destruction. Currently, 2.45-GHz ablation systems are gaining prominence because of the shorter application times required. The aims of this study were to determine optimal power and time to ablation volume (AbV) ratios for a new 1.8-mm-2.45-GHz antenna using ex vivo tissue models. Methods. The 1.8-mm-2.45-GHz Accu2i MWA system was employed to perform ablations in bovine liver, porcine muscle, and porcine kidney ex vivo. Whole tissues were prewarmed (35°C) and multiple ablations performed at power settings of 60 to 180 W for 2- to 6-minute time intervals. Postablation, tissues were dissected, AbVs calculated, and correlations to power and time settings made. Results. Significant increases in AbV were measured between each of the time points for a constant power setting in all 3 tissues. Increasing power settings led to significant increases in AbV at power settings ?140 W. However, no significant increase in AbV was obtained at power settings >140 W. Conclusions. Optimal efficiency for MWA using a new 1.8-mm-2.45-GHz system is achieved at settings of ?140 W for 6 minutes in a range of ex vivo tissue and no additional benefit occurs by increasing the power setting to 180 W in these tissues. PMID:24899579

Niemeyer, David J; Simo, Kerri A; McMillan, Matthew T; Seshadri, Ramanathan M; Hanna, Erin M; Swet, Jacob H; Swan, Ryan Z; Sindram, David; Martinie, John B; McKillop, Iain H; Iannitti, David A

2015-02-01

106

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

PubMed Central

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

2013-01-01

107

Thermal Optimization of Growth and Quality in Protein Crystals  

NASA Technical Reports Server (NTRS)

Experimental evidence suggests that larger and higher quality crystals can be attained in the microgravity of space; however, the effect of growth rate on protein crystal quality is not well documented. This research is the first step towards providing strategies to grow crystals under constant rates of growth. Controlling growth rates at a constant value allows for direct one-to-one comparison of results obtained in microgravity and on earth. The overall goal of the project was to control supersaturation at a constant value during protein crystal growth by varying temperature in a predetermined manner. Applying appropriate theory requires knowledge of specific physicochemical properties of the protein solution including the effect of supersaturation on growth rates and the effect of temperature on protein solubility. Such measurements typically require gram quantities of protein and many months of data acquisition. A second goal of the project applied microcalorimetry for the rapid determination of these physicochemical properties using a minimum amount of protein. These two goals were successfully implemented on hen egg-white lysozyme. Results of these studies are described in the attached reprints.

Wiencek, John M.

1996-01-01

108

Optimizing control of Fe catalysts for carbon nanotube growth.  

PubMed

One must control the size distribution of catalyst Fe nano-particles (NPs) very carefully if one is to have any chance of growing "super-aligned" carbon nanotube (CNT) forests which can be spun directly into yarns and pulled directly into long sheets. Control of the Fe Nps size is important during all phases, including: the catalyst deposition, annealing and forest growth. As a result, it is important to understand how NPs are affected by various experimental factors as well as how those catalyst NPs then cause the growth of the forests. This paper focuses on two key experimental factors: The as-deposited thickness of the Fe catalyst film and the use of hydrogen gas (H2) during anneal and growth. We found that the sheet resistance (Rs) of as-deposited Fe films is directly related to the average film thickness and can be used to estimate whether the films can catalyze the growth of super-aligned forests. The height of the CNT forests decrease with decreasing Rs, but only slowly. More importantly, CNTs grown on the largest and the smallest Rs films are less aligned. Instead, they are more curled and wavy due to the Fe NP dynamics. The use of Hydrogen (H2) affects the formation of Fe NPs from the as-deposited film as well as their composition during the forest growth. We find that the addition of H2 to a CNT forest growth process at 680 degrees C (C2H2/He [30/600 sccm]) increases the CNT alignment substantially. H2 can also reduce iron-oxides which otherwise would impede the formation of NPs. As a result, H2 has multiple roles: besides its chemical reactivity, H2 is important for catalyst reconstruction into NPs having a proper size distribution as well as surface density. PMID:22966629

Jung, Dae Woong; Lee, Kyung H; Kim, Jae Hak; Burk, Dorothea; Overzet, Lawrence J; Lee, Gil Sik; Kong, Seong Ho

2012-07-01

109

Resonance effects on the dynamics of dense granular beds: achieving optimal energy transfer in vibrated granular systems  

NASA Astrophysics Data System (ADS)

Using a combination of experimental techniques and discrete particle method simulations, we investigate the resonant behaviour of a dense, vibrated granular system. We demonstrate that a bed of particles driven by a vibrating plate may exhibit marked differences in its internal energy dependent on the specific frequency at which it is driven, even if the energy corresponding to the oscillations driving the system is held constant and the acceleration provided by the base remains consistently significantly higher than the gravitational acceleration, g. We show that these differences in the efficiency of energy transfer to the granular system can be explained by the existence of resonances between the bed’s bulk motion and that of the oscillating plate driving the system. We systematically study the dependency of the observed resonant behaviour on the system’s main, controllable parameters and, based on the results obtained, propose a simple empirical model capable of determining, for a given system, the points in parameter space for which optimal energy transfer may be achieved.

Windows-Yule, C. R. K.; Rosato, A. D.; Thornton, A. R.; Parker, D. J.

2015-02-01

110

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

PubMed Central

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

2013-01-01

111

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

Microsoft Academic Search

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

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

2006-01-01

112

Optimization of the growth conditions of the extremely thermophilic microorganisms Thermococcus celer and Pyrococcus woesei.  

PubMed

Growth medium components and cultivation conditions for the extremely thermophilic Archaea Thermococcus celer and Pyrococcus woesei were optimized. A culture media based in marine water was formulated. Both Archaea demonstrated to be strictly anaerobic with optimal growth temperature of 85 degrees and 95 degrees C, respectively. Sodium sulfide, but not cysteine, was used as a sulfur and reductive capacity source. It was observed that hydrogen sulfide could be replaced by 30 microM titanium (III) nitrile acetate. The addition of elemental S(o) enhanced growth of both microorganisms, with T. celer far more sensitive than P. woesei to the absence of S(o). P. woesei utilized maltose as a carbon source, while T. celer was able to use only peptides from yeast extract, peptone and tryptone as its carbon source. Optimum carbon source concentrations were 1.25 g/L for T. celer and 5 g/L for P. woesei. Although both Archaea required peptides as a nitrogen source, the addition of ammonia chloride to a nitrogen-limited media did not stimulate growth, which suggests that neither Archaea appear to metabolize ammonia. The growth of P. woesei, but not T. celer, was stimulated considerably in the presence of iron. Co, Ni, Zn, Mo. Mn and Mg were essential trace elements needed for optimal growth of both bacteria. PMID:10520597

Blamey, J; Chiong, M; López, C; Smith, E

1999-10-01

113

An optimal strategy to model microbial growth in a multiple substrate environment.  

PubMed

A comprehensive model is developed based on an optimal strategy describing varied microbial growth phenomenon involving sequential and simultaneous utilization of substrate. The model mimics the complex regulatory process of a cell which results in diverse growth process with the help of simple multi-variable constrained optimization, which aims at maximizing the specific cell growth. The metabolic processes of a cell are represented by simple flux balance equations. The different growth phenomenon exhibited by a microorganism are attributed to different levels of control present inside the cell. Provision is made in the model for these controls, in the form of constraints in the optimization formulation. The model prediction matches well with the experimental data of simultaneous growth of E. coli K12 on a mixture of glucose and organic acids like lactate, pyruvate, and acetate. Moreover, the model predictions are well in agreement with earlier published experimental data for the growth of E. coli K12 on other organic acids like fumarate, alpha-ketoglutarate, and succinate. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 635-644, 1997. PMID:18642335

Venkatesh, K V; Doshi, P; Rengaswamy, R

1997-12-20

114

Optimal strategy in chemotherapy for a Gompertzian model of cancer growth.  

PubMed

The problem of optimal cancer chemotherapy is reconsidered. For the assumed result of the therapy the cumulative negative toxic effect of the drug is minimized. The unknown function to be optimized is the time-dependent dose of the drug. The Gompertzian model of cell population growth is employed. The formulated problem of the calculus of variations is solved using the method of Miele (the method of extremization of linear integrals via Green's theorem). The optimal solution is unique and of "bang-bang" type with one switching point. PMID:19032003

Maro?ski, Ryszard

2008-01-01

115

The roles of hope and optimism on posttraumatic growth in oral cavity cancer patients.  

PubMed

To investigate the association of the positive coping strategies, hope and optimism, on posttraumatic growth (PTG) in oral cavity (OC) cancer patients. A retrospective cross-sectional study was conducted and performed in the outpatient station of the Oral and Maxillofacial Surgery at the University of Hong Kong, Hong Kong SAR, PR China. Fifty patients successfully treated for OC cancer were recruited after their informed consents had been obtained during the review clinic. During their regular follow-up controls in the outpatient clinic, the patients compiled the posttraumatic growth inventory (PTGI) questionnaire, hope scale (HS) and the life orientation scale-revised (LOT-R). Hope and optimism correlated significantly positive with PTG and accounting together for a 25% variance of posttraumatic growth. Hope positively correlated with posttraumatic growth (r=.49, p<.001) as well as optimism (r=.31, p<.05). When compared to unmarried patients, married patients showed high levels of PTG and hope (married participants: mean=53.15, SD=11.04; unmarried participants: mean=41.00, SD=6.36; t (48)=2.403, p<.05). Hope and optimism represent important indicators for PTG in OC cancer patients. An intact dyad relationship seems to be important for hope and consecutive higher levels of PTG when compared to unmarried patients. Supportive psychological treatment strategies related to these two coping factors might be beneficial for OC cancer patients. PMID:21183398

Ho, Samuel; Rajandram, Rama Krsna; Chan, Natalie; Samman, Nabil; McGrath, Colman; Zwahlen, Roger Arthur

2011-02-01

116

Growth  

NASA Astrophysics Data System (ADS)

This chapter is devoted to the growth of ZnO. It starts with various techniques to grow bulk samples and presents in some detail the growth of epitaxial layers by metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and pulsed laser deposition (PLD). The last section is devoted to the growth of nanorods. Some properties of the resulting samples are also presented. If a comparison between GaN and ZnO is made, very often the huge variety of different growth techniques available to fabricate ZnO is said to be an advantage of this material system. Indeed, growth techniques range from low cost wet chemical growth at almost room temperature to high quality MOCVD growth at temperatures above 1, 000?C. In most cases, there is a very strong tendency of c-axis oriented growth, with a much higher growth rate in c-direction as compared to other crystal directions. This often leads to columnar structures, even at relatively low temperatures. However, it is, in general, not straight forward to fabricate smooth ZnO thin films with flat surfaces. Another advantage of a potential ZnO technology is said to be the possibility to grow thin films homoepitaxially on ZnO substrates. ZnO substrates are mostly fabricated by vapor phase transport (VPT) or hydrothermal growth. These techniques are enabling high volume manufacturing at reasonable cost, at least in principle. The availability of homoepitaxial substrates should be beneficial to the development of ZnO technology and devices and is in contrast to the situation of GaN. However, even though a number of companies are developing ZnO substrates, only recently good quality substrates have been demonstrated. However, these substrates are not yet widely available. Still, the situation concerning ZnO substrates seems to be far from low-cost, high-volume production. The fabrication of dense, single crystal thin films is, in general, surprisingly difficult, even when ZnO is grown on a ZnO substrate. However, molecular beam epitaxy (MBE) delivers high quality ZnMgO-ZnO quantum well structures. Other thin film techniques such as PLD or MOCVD are also widely used. The main problem at present is to consistently achieve reliable p-type doping. For this topic, see also Chap. 5. In the past years, there have been numerous publications on p-type doping of ZnO, as well as ZnO p-n junctions and light emitting diodes (LEDs). However, a lot of these reports are in one way or the other inconsistent or at least incomplete. It is quite clear from optical data that once a reliable hole injection can be achieved, high brightness ZnO LEDs should be possible. In contrast to that expectation, none of the LEDs reported so far shows efficient light emission, as would be expected from a reasonable quality ZnO-based LED. See also Chap. 13. As a matter of fact, there seems to be no generally accepted and reliable technique for p-type doping available at present. The reason for this is the unfavorable position of the band structure of ZnO relative to the vacuum level, with a very low lying valence band. See also Fig. 5.1. This makes the incorporation of electrically active acceptors difficult. Another difficulty is the huge defect density in ZnO. There are many indications that defects play a major role in transport and doping. In order to solve the doping problem, it is generally accepted that the quality of the ZnO material grown by the various techniques needs to be improved. Therefore, the optimization of ZnO epitaxy is thought to play a key role in the further development of this material system. Besides being used as an active material in optoelectronic devices, ZnO plays a major role as transparent contact material in thin film solar cells. Polycrystalline, heavily n-type doped ZnO is used for this, combining a high electrical conductivity with a good optical transparency. In this case, ZnO thin films are fabricated by large area growth techniques such as sputtering. For this and other applications, see also Chap. 13.

Waag, Andreas

117

Reducing the Academic Risks of Over-Optimism: The Longitudinal Effects of Attributional Retraining on Cognition and Achievement  

ERIC Educational Resources Information Center

Although optimism is generally regarded as a positive dispositional characteristic, unmitigated optimism can be problematic. The adaptiveness of overly optimistic expectations in novel or unfamiliar settings is questionable because individuals have little relevant experience on which to base such expectations. In this four-phase longitudinal…

Haynes, Tara L.; Ruthig, Joelle C.; Perry, Raymond P.; Stupnisky, Robert H.; Hall, Nathan C.

2006-01-01

118

A Study of the Growth Patterns in Language, Communication, and Educational Achievement in Six Residential Schools for Deaf Students.  

ERIC Educational Resources Information Center

Communication skills, language abilities, and educational achievement of 163 subjects from six residential schools for deaf students were studied. Subjects were tested yearly from 1963 to 1967 on speechreading, fingerspelling, speech intelligibility, reading achievement, arithmetic achievement, and written language. Both males and females and the…

Babbini, Barbara E.; Quigley, Stephen P.

119

Optimization of a thermal-CVD system for carbon nanotube growth  

NASA Astrophysics Data System (ADS)

We illustrate the optimization of the operation of a thermal chemical vapor deposition (CVD) system for the growth of carbon nanotubes (CNT). We have studied the deposition parameters using the Taguchi matrix robust design approach. The CVD system, which employs solid precursors (camphor and ferrocene) carried by nitrogen gas flow through a hot deposition zone, where the deposition of carbon nanostructures takes place, involves a large number of tunable parameters that have to be optimized. With the aim of getting the best configuration for the development of massive and well-oriented CNT carpets, the Taguchi method allowed us to improve our system leading to the growth of extremely long CNTs (few millimeters) at a high deposition rate (500 nm/s) and yield (30% in weight of the carbon precursors feedstock), which were characterized by electron microscopy. We found that the growth temperature had the most important influence on the CNT diameter, whereas the substrate tilt wit respect to gas flow did not influence their growth (i.e. CNTs grow on every side of the silicon wafer substrates, always normal to the substrate surface). The carrier gas flow and catalyst concentration both showed a secondary impact on CNT growth, though they showed a consistent correlation to the growth temperature.

Porro, S.; Musso, S.; Giorcelli, M.; Chiodoni, A.; Tagliaferro, A.

2007-03-01

120

Optimizing Performance on Linux Clusters Using Advanced Communication Protocols: Achieving Over 10 Teraflops on a 8.6 Teraflops Linpack-Rated Linux Cluster  

SciTech Connect

Advancements in high-performance networks (Quadrics, Infiniband or Myrinet) continue to improve the efficiency of modern clusters. However, the average application efficiency is as small fraction of the peak as the system’s efficiency. This paper describes techniques for optimizing application performance on Linux clusters using Remote Memory Access communication protocols. The effectiveness of these optimizations is presented in the context of an application kernel, dense matrix multiplication. The result was achieving over 10 teraflops on HP Linux cluster on which LINPACK performance is measured as 8.6 teraflops.

Krishnan, Manoj Kumar; Nieplocha, Jarek

2005-04-26

121

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

PubMed

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

Ketseoglou, Irene; Bouwer, Gustav

2013-08-10

122

Branched-Chain Amino Acid Biosynthesis Is Essential for Optimal Growth of Streptococcus thermophilus in Milk  

PubMed Central

Lactic acid bacteria are nutritionally demanding bacteria which need, among other things, amino acids for optimal growth. We identified the branched-chain amino acid (BCAA) biosynthesis pathway as an essential pathway for optimal growth of Streptococcus thermophilus in milk. Through random insertional mutagenesis, we isolated and characterized two mutants for which growth in milk is affected as a consequence of ilvB and ilvC gene interruptions. This situation demonstrates that the BCAA biosynthesis pathway is active in S. thermophilus. BCAA biosynthesis is necessary but not sufficient for optimal growth of S. thermophilus and is subject to retro-inhibition processes. The specificity of the BCAA biosynthesis pathway in S. thermophilus lies in the independent transcription of the ilvC gene encoding a keto acid reductoisomerase acting on acetolactate at the junction of the BCAA and acetoin biosynthesis pathways. The possible advantages for S. thermophilus of keeping this biosynthesis pathway active could be linked either to adaptation of the organism to milk, which is different than that of other dairy bacteria, or to the role of the pathway in maintaining the internal pH. PMID:11097879

Garault, P.; Letort, C.; Juillard, V.; Monnet, V.

2000-01-01

123

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

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…

Shin, Tacksoo

2007-01-01

124

Late Immersion and Language of Instruction in Hong Kong High Schools: Achievement Growth in Language and Nonlanguage Subjects.  

ERIC Educational Resources Information Center

For Hong Kong high school students (n=12,784), late immersion in English as the language of instruction had large negative effects on science, geography, and history achievement. English immersion had small positive effects on English and Chinese achievement. Effects of language of instruction did not vary substantially over the first 3 years of…

Marsh, Herbert W.; Hau, Kit-Tai; Kong, Chit-Kwong

2000-01-01

125

Optimized clinical performance of growth hormone with an expanded genetic code  

PubMed Central

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

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

126

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

PubMed

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

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

2010-06-01

127

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

Microsoft Academic Search

.   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;

Nicolas Galtier; J. R. Lobry

1997-01-01

128

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

Microsoft Academic Search

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

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

2006-01-01

129

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

Microsoft Academic Search

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

John Darrell Bess

2008-01-01

130

Forced sustained swimming exercise at optimal speed enhances growth of juvenile yellowtail kingfish (Seriola lalandi)  

PubMed Central

Swimming exercise at optimal speed may optimize growth performance of yellowtail kingfish in a recirculating aquaculture system. Therefore, optimal swimming speeds (Uopt in m s?1 or body lengths s?1, BL s?1) were assessed and then applied to determine the effects of long-term forced and sustained swimming at Uopt on growth performance of juvenile yellowtail kingfish. Uopt was quantified in Blazka-type swim-tunnels for 145, 206, and 311 mm juveniles resulting in values of: (1) 0.70 m s?1 or 4.83 BL s?1, (2) 0.82 m s?1 or 3.25 BL s?1, and (3) 0.85 m s?1 or 2.73 BL s?1. Combined with literature data from larger fish, a relation of Uopt (BL s?1) = 234.07(BL)?0.779 (R2 = 0.9909) was established for this species. Yellowtail kingfish, either forced to perform sustained swimming exercise at an optimal speed of 2.46 BL s?1 (“swimmers”) or allowed to perform spontaneous activity at low water flow (“resters”) in a newly designed 3600 L oval flume (with flow created by an impeller driven by an electric motor), were then compared. At the start of the experiment, ten fish were sampled representing the initial condition. After 18 days, swimmers (n = 23) showed a 92% greater increase in BL and 46% greater increase in BW as compared to resters (n = 23). As both groups were fed equal rations, feed conversion ratio (FCR) for swimmers was 1.21 vs. 1.74 for resters. Doppler ultrasound imaging showed a statistically significant higher blood flow (31%) in the ventral aorta of swimmers vs. resters (44 ± 3 vs. 34 ± 3 mL min?1, respectively, under anesthesia). Thus, growth performance can be rapidly improved by optimal swimming, without larger feed investments. PMID:25620933

Palstra, Arjan P.; Mes, Daan; Kusters, Kasper; Roques, Jonathan A. C.; Flik, Gert; Kloet, Kees; Blonk, Robbert J. W.

2015-01-01

131

Cement-retained versus screw-retained implant restorations: Achieving optimal occlusion and esthetics in implant dentistry  

Microsoft Academic Search

Statement of problem. Optimal occlusion and esthetics are goals in prosthetic treatment. Implant dentistry is no exception.Purpose of article. The purpose of this article is to discuss how the choice to use screw-retained or cement-retained implants dramatically influences the occlusion and esthetics. (J Prosthet Dent 1997;77:28-35.)

Kenneth S. Hebel; Reena C. Gajjar

1997-01-01

132

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

ERIC Educational Resources Information Center

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…

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

133

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

SciTech Connect

After hundreds of generations of mid log phase growth, Escherichia coli acquires a higher growth rate as predicted using flux balance analysis (FBA) on genome-scale metabolic models (GEMs). FBA solutions contain hundreds of variables that can be examined using omics methods. We report that 99% of active reactions from FBA optimal growth solutions are supported by transcriptomic and proteomic data. Moreover, when E. coli adapts to growth rate selective pressure, the resulting evolved strains reinforce the optimal growth predictions. Specifically, through constraint-based analysis of the proteomic and transcriptomic data, we find: 1) selective pressure for the predicted optimal growth states and a minimization of network flux; 2) suppression of genes outside of the optimal growth solutions; and 3) a trend towards usage of more efficient metabolic pathways. For processes not in GEMs, we find 4) an increase in the transcription/translation machinery and stringent response suppression, and 5) that established regulons are significantly down-regulated. Thus, differential expression supports observed growth phenotype changes, and observed expression in evolved strains is consistent with GEM computed optimal growth states.

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

2010-07-27

134

Academic Abilities in Children and Adolescents with a History of Autism Spectrum Disorders Who Have Achieved Optimal Outcomes  

ERIC Educational Resources Information Center

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…

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

2014-01-01

135

Optimal Culture Conditions for Mycelial Growth and Exo-polymer Production of Ganoderma applanatum  

PubMed Central

The effect of fermentation parameters and medium composition on the simultaneous mycelial growth and exo-polymer production from submerged cultures of Ganoderma applanatum was investigated in shake-flask cultures. The optimum initial pH for mycelial growth and exo-polymer production was 5.0 and 6.0, respectively. The optimum temperature was 25? and the optimum inoculum content was 3.0% (v/v). The optimal carbon and nitrogen sources were glucose and corn steep powder, respectively. After 12 days fermentation under these conditions, the highest mycelial growth was 18.0 g/l and the highest exo-polymer production was 3.9 g/l. PMID:23983515

Jeong, Yong-Tae; Jeong, Sang-Chul; Yang, Byung-Keun; Islam, Rezuanul

2009-01-01

136

Optimal photosynthetic use of light by tropical tree crowns achieved by adjustment of individual leaf angles and nitrogen content  

PubMed Central

Background and Aims Theory for optimal allocation of foliar nitrogen (ONA) predicts that both nitrogen concentration and photosynthetic capacity will scale linearly with gradients of insolation within plant canopies. ONA is expected to allow plants to efficiently use both light and nitrogen. However, empirical data generally do not exhibit perfect ONA, and light-use optimization per se is little explored. The aim was to examine to what degree partitioning of nitrogen or light is optimized in the crowns of three tropical canopy tree species. Methods Instantaneous photosynthetic photon flux density (PPFD) incident on the adaxial surface of individual leaves was measured along vertical PPFD gradients in tree canopies at a frequency of 0·5 Hz over 9–17 d, and summed to obtain the average daily integral of PPFD for each leaf to characterize its insolation regime. Also measured were leaf N per area (Narea), leaf mass per area (LMA), the cosine of leaf inclination and the parameters of the photosynthetic light response curve [photosynthetic capacity (Amax), dark respiration (Rd), apparent quantum yield (?) and curvature (?)]. The instantaneous PPFD measurements and light response curves were used to estimate leaf daily photosynthesis (Adaily) for each leaf. Key Results Leaf Narea and Amax changed as a hyperbolic asymptotic function of the PPFD regime, not the linear relationship predicted by ONA. Despite this suboptimal nitrogen partitioning among leaves, Adaily did increase linearly with PPFD regime through co-ordinated adjustments in both leaf angle and physiology along canopy gradients in insolation, exhibiting a strong convergence among the three species. Conclusions The results suggest that canopy tree leaves in this tropical forest optimize photosynthetic use of PPFD rather than N per se. Tropical tree canopies then can be considered simple ‘big-leaves’ in which all constituent ‘small leaves’ use PPFD with the same photosynthetic efficiency. PMID:19151040

Posada, Juan M.; Lechowicz, Martin J.; Kitajima, Kaoru

2009-01-01

137

Thermal Preference of Juvenile Dover Sole (Solea solea) in Relation to Thermal Acclimation and Optimal Growth Temperature  

PubMed Central

Dover sole (Solea solea) is an obligate ectotherm with a natural thermal habitat ranging from approximately 5 to 27°C. Thermal optima for growth lie in the range of 20 to 25°C. More precise information on thermal optima for growth is needed for cost-effective Dover sole aquaculture. The main objective of this study was to determine the optimal growth temperature of juvenile Dover sole (Solea solea) and in addition to test the hypothesis that the final preferendum equals the optimal growth temperature. Temperature preference was measured in a circular preference chamber for Dover sole acclimated to 18, 22 and 28°C. Optimal growth temperature was measured by rearing Dover sole at 19, 22, 25 and 28°C. The optimal growth temperature resulting from this growth experiment was 22.7°C for Dover sole with a size between 30 to 50 g. The temperature preferred by juvenile Dover sole increases with acclimation temperature and exceeds the optimal temperature for growth. A final preferendum could not be detected. Although a confounding effect of behavioural fever on temperature preference could not be entirely excluded, thermal preference and thermal optima for physiological processes seem to be unrelated in Dover sole. PMID:23613837

Schram, Edward; Bierman, Stijn; Teal, Lorna R.; Haenen, Olga; van de Vis, Hans; Rijnsdorp, Adriaan D.

2013-01-01

138

Regeneration of viable oil palm plants from protoplasts by optimizing media components, growth regulators and cultivation procedures.  

PubMed

Oil palm protoplasts are suitable as a starting material for the production of oil palm plants with new traits using approaches such as somatic hybridization, but attempts to regenerate viable plants from protoplasts have failed thus far. Here we demonstrate, for the first time, the regeneration of viable plants from protoplasts isolated from cell suspension cultures. We achieved a protoplast yield of 1.14×10(6) per gram fresh weight with a viability of 82% by incubating the callus in a digestion solution comprising 2% cellulase, 1% pectinase, 0.5% cellulase onuzuka R10, 0.1% pectolyase Y23, 3% KCl, 0.5% CaCl2 and 3.6% mannitol. The regeneration of protoplasts into viable plants required media optimization, the inclusion of plant growth regulators and the correct culture technique. Microcalli derived from protoplasts were obtained by establishing agarose bead cultures using Y3A medium supplemented with 10?M naphthalene acetic acid, 2?M 2,4-dichlorophenoxyacetic acid, 2?M indole-3-butyric acid, 2?M gibberellic acid and 2?M 2-?-dimethylallylaminopurine. Small plantlets were regenerated from microcalli by somatic embryogenesis after successive subculturing steps in medium with limiting amounts of growth regulators supplemented with 200mg/l ascorbic acid. PMID:23849119

Masani, Mat Yunus Abdul; Noll, Gundula; Parveez, Ghulam Kadir Ahmad; Sambanthamurthi, Ravigadevi; Prüfer, Dirk

2013-09-01

139

Growth dominant co-precipitation process to achieve high coercivity at room temperature in CoFe2O4 nanoparticles  

Microsoft Academic Search

Applications of CoFe2O4 are limited due to the lack of synthesis technique to produce monodispersed, single domain and high coercivity (Hc) nanoparticles. Here, we describe the growth dominant co-precipitation process to achieve high Hc, with moderate magnetization at room temperature (RT) in CoFe2O4 nanoparticles. It is well known that the particle size is closely related to the relative interdependence between

C. N. Chinnasamy; B. Jeyadevan; O. Perales-Perez; K. Shinoda; K. Tohji; A. Kasuya

2002-01-01

140

The study of growth between academic self-concept, nonacademic self-concept, and academic achievement of ninth-grade students: a multiple group analysis  

Microsoft Academic Search

The two purposes of this research were to develop and validate latent growth curve model between academic self-concept, nonacademic self-concept, and academic achievement and to test invariance of model form and parameters in the model between boy and girl groups of students. The research samples were 820 nine-grade students. The research instruments consisted of Self-descriptive Questionnaire and The student academic

Suntonrapot Damrongpanit

141

Methodology, morphology, and optimization of carbon nanotube growth for improved energy storage in a double layer capacitor  

E-print Network

The goal of this thesis is to optimize the growth of carbon nanotubes (CNTs) on a conducting substrate for use as an electrode to improve energy density in a double-layer capacitor. The focus has been on several areas, ...

Ku, Daniel C. (Daniel Chung-Ming), 1985-

2009-01-01

142

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

ERIC Educational Resources Information Center

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…

Robinson, Joseph P.

2008-01-01

143

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

PubMed

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. Biotechnol. Bioeng. 2015;112: 288-296. © 2014 Wiley Periodicals, Inc. PMID:25182602

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

2015-02-01

144

Maximizing and Optimizing the Large Scale Deployment of Renewable Energy: Achieving the U.S. Government's Goal of 20% by 2030  

NASA Astrophysics Data System (ADS)

The United States Government has an ambitious goal of growing renewable energy from 1% to 20% by 2030. Two key challenges exist in order to realize this target: Creating system-level approaches to overall generation capacity expansion and integration, including difficult policy changes, and addressing the variability issues of wind and solar generation. These challenges are addressed using MORE Power (Maximizing and Optimizing Renewable Energy), a system level planning tool designed to optimize the placement of wind and solar sites to maximize high quality, useable power. This planning tool uses historical, high resolution, measurements of wind and solar parameters along with a unique, non-linear, optimization algorithm to optimize the placement of sites given a set of user specified input parameters. MORE Power is quantifying the real value of transmission as an enabler to aggregate diverse variable resources which in turn is incentivizing transmission developers to expand the grid. In addition, the issue of grid stability becomes even more critical as larger deployment of renewable resources come online. MORE Power is identifying the benefits of larger balancing areas as an enabler for greater stability and therefore a reduced need to keep transmission capacity in reserve. In the end, by addressing and minimizing the impacts of the natural variability of wind and solar, a reduction in price volatility results which favorably impacts the consumer. This presentation will show examples of how MORE Power is being used to address the variability issue of renewables in order to achieve the 20% deployment target by 2030.

Alliss, R.; Apling, D.; Kiley, H.; Mason, M.

2011-12-01

145

Optimizing the charge balance of fluorescent organic light-emitting devices to achieve high external quantum efficiency beyond the conventional upper limit.  

PubMed

The external quantum efficiencies (EQEs) of fluorescent light emitting devices are drastically improved by optimizing the charge balance. When N,N'-di(naphthalene-1-yl)- N,N'-diphenylbenzidine (NPD) is used as a hole-transporting layer (HTL) and Alq(3) as an electron-transporting layer (ETL) with the green dopant 2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-10-(2-benzothiazolyl)quinolizino-[9,9a,1gh]coumarin (C545T), the EQE is observed to be approximately 3%. However, when the HTL and ETL materials are optimized, a 7.5% external quantum efficiency (EQE) in a green-emitting device and an 8.2% EQE in a blue-emitting device are achieved at 100 cd m(-2) . PMID:22407953

Pu, Yong-Jin; Nakata, Go; Satoh, Fumiya; Sasabe, Hisahiro; Yokoyama, Daisuke; Kido, Junji

2012-04-01

146

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

E-print Network

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

Paris-Sud XI, Université de

147

ACHIEVING NEW SOURCE PERFORMANCE STANDARDS (NSPS) EMISSION STANDARDS THROUGH INTEGRATION OF LOW-NOx BURNERS WITH AN OPTIMIZATION PLAN FOR BOILER COMBUSTION  

SciTech Connect

The objective of this project is to demonstrate the use of an Integrated Combustion Optimization System to achieve NO{sub x} emissions levels in the range of 0.15 to 0.22 lb/MMBtu while simultaneously enabling increased power output. The project consists of the integration of low-NO{sub x} burners and advanced overfire air technology with various process measurement and control devices on the Holcomb Station Unit 1 boiler. The project includes the use of sophisticated neural networks or other artificial intelligence technologies and complex software that can optimize several operating parameters, including NO{sub x} emissions, boiler efficiency, and CO emissions. The program is being performed in three phases. In Phase I, the boiler is being equipped with sensors that can be used to monitor furnace conditions and coal flow to permit improvements in boiler operation. In Phase II, the boiler will be equipped with burner modifications designed to reduce NO{sub x} emissions and automated coal flow dampers to permit on-line fuel balancing. In Phase III, the boiler will be equipped with an overfire air system to permit deep reductions in NO{sub x} emissions to be achieved. Integration of the overfire air system with the improvements made in Phases I and II will permit optimization of the boiler performance, output, and emissions. During this reporting period, efforts were focused on completion of Phase I and Phase II activities. The low-NO{sub x} burner modifications, the coal flow dampers, and the coal flow monitoring system were procured and installed during a boiler outage in March 2003. During this reporting period, optimization tests were performed to evaluate system performance and identify optimum operating conditions for the installed equipment. The overfire air system process design activities and preliminary engineering design were completed.

Wayne Penrod; David Moyeda

2003-07-01

148

Optimal growth temperature of prokaryotes correlates with class II amino acid composition.  

PubMed

Partitioning of aminoacyl-tRNA synthetases and their associated amino acids into two classes allows us to distinguish between thermophilic and mesophilic species based only on amino acids composition. The CLASSDB program has been developed for amino acid content analysis in organisms treated individually or pooled together to form a pattern of characteristic properties. A strong correlation has been observed between optimal growth temperature (OGT) of organisms and class II amino acids content. Amino acid composition in organisms closely related phylogenetically but dissimilar in their OGT testifies that thermo-adaptation happens rather rapidly on the time scale of evolution. PMID:16497302

Klipcan, Liron; Safro, Ilya; Temkin, Boris; Safro, Mark

2006-03-01

149

Combinatorial Optimization of Heterogeneous Catalysts Used in the Growth of Carbon Nanotubes  

NASA Technical Reports Server (NTRS)

Libraries of liquid-phase catalyst precursor solutions were printed onto iridium-coated silicon substrates and evaluated for their effectiveness in catalyzing the growth of multi-walled carbon nanotubes (MWNTs) by chemical vapor deposition (CVD). The catalyst precursor solutions were composed of inorganic salts and a removable tri-block copolymer (EO)20(PO)70(EO)20 (EO = ethylene oxide, PO = propylene oxide) structure-directing agent (SDA), dissolved in ethanol/methanol mixtures. Sample libraries were quickly assayed using scanning electron microscopy after CVD growth to identify active catalysts and CVD conditions. Composition libraries and focus libraries were then constructed around the active spots identified in the discovery libraries to understand how catalyst precursor composition affects the yield, density, and quality of the nanotubes. Successful implementation of combinatorial optimization methods in the development of highly active, carbon nanotube catalysts is demonstrated, as well as the identification of catalyst formulations that lead to varying densities and shapes of aligned nanotube towers.

Cassell, Alan M.; Verma, Sunita; Delzeit, Lance; Meyyappan, M.; Han, Jie

2000-01-01

150

Technology for monitoring shot-level light source performance data to achieve high-optimization of lithography processes  

NASA Astrophysics Data System (ADS)

Gigaphoton has developed a new monitoring system that provides shot-level light source performance data to FDC systems during exposure time. The system provides basic monitoring data (e.g. Energy, Wavelength, Bandwidth, etc.) and beam performance data, such as Beam Profile, Pointing, Divergence, Polarization can also be monitored using a new metrology tool called the Beam Performance Monitor (BPM) module. During exposure time the system automatically identifies the start and end timing of the wafer and each shot based on the burst of firing signals from the scanner, and stores the measured data in sequence. The stored data is sorted by wafer or by shot, and sent to REDeeM Piece which in turn converts the data to the user's protocol and send it to the FDC system. The user also has the option to directly view or download the stored data using a GUI. Through this monitoring system, users can manage light sources data at the shot or reticle level to facilitate optimization of performance and running cost of the light source for each process. This monitoring system can be easily retrofitted to Gigaphoton's current ArF laser light sources. The beam splitter of the BPM was specially designed to bend only a small fraction of the source beam, so we are able to simply install the BPM without the need for special optical alignment.

Moriya, Masato; Ochiai, Hideyuki; Watabe, Yoshinobu; Ishida, Keisuke; Masuda, Hiroyuki; Sasaki, Youichi; Kumazaki, Takahito; Kurosu, Akihiko; Ohta, Takeshi; Kakizaki, Kouji; Matsunaga, Takashi; Mizoguchi, Hakaru

2014-03-01

151

Rod visual pigment optimizes active state to achieve efficient G protein activation as compared with cone visual pigments.  

PubMed

Most vertebrate retinas contain two types of photoreceptor cells, rods and cones, which show different photoresponses to mediate scotopic and photopic vision, respectively. These cells contain different types of visual pigments, rhodopsin and cone visual pigments, respectively, but little is known about the molecular properties of cone visual pigments under physiological conditions, making it difficult to link the molecular properties of rhodopsin and cone visual pigments with the differences in photoresponse between rods and cones. Here we prepared bovine and mouse rhodopsin (bvRh and mRh) and chicken and mouse green-sensitive cone visual pigments (cG and mG) embedded in nanodiscs and applied time-resolved fluorescence spectroscopy to compare their Gt activation efficiencies. Rhodopsin exhibited greater Gt activation efficiencies than cone visual pigments. Especially, the Gt activation efficiency of mRh was about 2.5-fold greater than that of mG at 37 °C, which is consistent with our previous electrophysiological data of knock-in mice. Although the active state (Meta-II) was in equilibrium with inactive states (Meta-I and Meta-III), quantitative determination of Meta-II in the equilibrium showed that the Gt activation efficiency per Meta-II of bvRh was also greater than those of cG and mG. These results indicated that efficient Gt activation by rhodopsin, resulting from an optimized active state of rhodopsin, is one of the causes of the high amplification efficiency of rods. PMID:24375403

Kojima, Keiichi; Imamoto, Yasushi; Maeda, Ryo; Yamashita, Takahiro; Shichida, Yoshinori

2014-02-21

152

ACHIEVING NEW SOURCE PERFORMANCE STANDARDS (NSPS) EMISSION STANDARDS THROUGH INTEGRATION OF LOW-NOx BURNERS WITH AN OPTIMIZATION PLAN FOR BOILER COMBUSTION  

SciTech Connect

The objective of this project is to demonstrate the use of an Integrated Combustion Optimization System to achieve NO{sub x} emissions levels in the range of 0.15 to 0.22 lb/MMBtu while simultaneously enabling increased power output. The project consists of the integration of low-NO{sub x} burners and advanced overfire air technology with various process measurement and control devices on the Holcomb Station Unit 1 boiler. The project includes the use of sophisticated neural networks or other artificial intelligence technologies and complex software that can optimize several operating parameters, including NO{sub x} emissions, boiler efficiency, and CO emissions. The program is being performed in three phases. In Phase I, the boiler is being equipped with sensors that can be used to monitor furnace conditions and coal flow to permit improvements in boiler operation. In Phase II, the boiler will be equipped with burner modifications designed to reduce NO{sub x} emissions and automated coal flow dampers to permit on-line fuel balancing. In Phase III, the boiler will be equipped with an overfire air system to permit deep reductions in NO{sub x} emissions to be achieved. Integration of the overfire air system with the improvements made in Phases I and II will permit optimization of the boiler performance, output, and emissions. During this reporting period, efforts were focused on Phase I and Phase II activities. The furnace sensors were procured and installed in February 2003. Baseline testing was performed following the sensor installation. The low-NO{sub x} burner modifications, the coal flow dampers, and the coal flow monitoring system were procured and installed during a boiler outage in March 2003. Process design activities were performed to support design of the equipment installed and to develop specifications for the overfire air system. The overfire air system preliminary engineering design was initiated.

Wayne Penrod; David Moyeda

2003-04-01

153

Optimization of the purification methods for recovery of recombinant growth hormone from Paralichthys olivaceus  

NASA Astrophysics Data System (ADS)

This study aimed to optimize the purification of recombinant growth hormone from Paralichthys olivaceus. Recombinant flounder growth hormone (r-fGH) was expressed by Escherichia coli in form of inclusion body or as soluble protein under different inducing conditions. The inclusion body was renatured using two recovery methods, i.e., dilution and dialysis. Thereafter, the refolded protein was purified by Glutathione Sepharase 4B affinity chromatography and r-fGH was obtained by cleavage of thrombin. For soluble products, r-fGH was directly purified from the lysates by Glutathione Sepharase 4B affinity chromatography. ELISA-receptor assay demonstrated that despite its low receptor binding activity, the r-fGH purified from refolded inclusion body had a higher yield (2.605 mg L-1) than that from soluble protein (1.964 mg L-1). Of the tested recovery methods, addition of renaturing buffer (pH 8.5) into denatured inclusion body yielded the best recovery rate (17.9%). This work provided an optimized purification method for high recovery of r-fGH, thus contributing to the application of r-fGH to aquaculture.

Zang, Xiaonan; Zhang, Xuecheng; Mu, Xiaosheng; Liu, Bin

2013-03-01

154

Transient Growth Theory Prediction of Optimal Placing of Passive and Active Flow Control Devices for Separation Delay in LPT Airfoils  

NASA Technical Reports Server (NTRS)

An analysis of the non-modal growth of perturbations in a boundary layer in the presence of a streamwise pressure gradient is presented. The analysis is based on PSE equations for an incompressible fluid. Examples with Falkner-Skan profiles indicate that a favorable pressure gradient decreases the non-modal growth while an unfavorable pressure gradient leads to an increase of the amplification. It is suggested that the transient growth mechanism be utilized to choose optimal parameters of tripping elements on a low-pressure turbine (LPT) airfoil. As an example, a boundary layer flow with a streamwise pressure gradient corresponding to the pressure distribution over a LPT airfoil is considered. It is shown that there is an optimal spacing of the tripping elements and that the transient growth effect depends on the starting point. At very low Reynolds numbers, there is a possibility to enhance the transient energy growth by means of wall cooling.

Tumin, Anatoli; Ashpis, David E.

2003-01-01

155

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

PubMed

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

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

2006-01-01

156

An Axenic Plant Culture System for Optimal Growth in Long-Term Studies: Design and Maintenance  

NASA Technical Reports Server (NTRS)

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. DII) 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 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 micro-g/d. Fumaric, malic, malonic, oxalic, and succinic acids were measured as components of the root exudates.

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

2006-01-01

157

Optimized invertase expression and secretion cassette for improving Yarrowia lipolytica growth on sucrose for industrial applications.  

PubMed

Yarrowia lipolytica requires the expression of a heterologous invertase to grow on a sucrose-based substrate. This work reports the construction of an optimized invertase expression cassette composed of Saccharomyces cerevisiae Suc2p secretion signal sequence followed by the SUC2 sequence and under the control of the strong Y. lipolytica pTEF promoter. This new construction allows a fast and optimal cleavage of sucrose into glucose and fructose and allows cells to reach the maximum growth rate. Contrary to pre-existing constructions, the expression of SUC2 is not sensitive to medium composition in this context. The strain JMY2593, expressing this new cassette with an optimized secretion signal sequence and a strong promoter, produces 4,519 U/l of extracellular invertase in bioreactor experiments compared to 597 U/l in a strain expressing the former invertase construction. The expression of this cassette strongly improved production of invertase and is suitable for simultaneously high production level of citric acid from sucrose-based media. PMID:24061566

Lazar, Zbigniew; Rossignol, Tristan; Verbeke, Jonathan; Crutz-Le Coq, Anne-Marie; Nicaud, Jean-Marc; Robak, Ma?gorzata

2013-11-01

158

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

SciTech Connect

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.

David Shropshire

2009-09-01

159

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

PubMed

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

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

160

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

NASA Astrophysics Data System (ADS)

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".

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

2008-04-01

161

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

NASA Technical Reports Server (NTRS)

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.

Tiller, Michael M.

1995-01-01

162

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

NASA Astrophysics Data System (ADS)

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.

Jeganathan, K.; Shimizu, M.

2014-09-01

163

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

SciTech Connect

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.

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

164

Growth optimization of Zataria multiflora Boiss. tissue cultures and rosmarinic acid production improvement.  

PubMed

In order to improve the growth of Zataria multiflora tissues in vitro experiments in different hormonal treatments and culture media were carried out. Shoot cultures, established from plantlets shoot apex, were treated by different levels of 6-benzylaminopurine and 1-naphtalen acetic acid added to Murashige and Skoog medium with two conditions of active charcoal. The highest proliferation rate was obtained with 1 mg L(-1) 6-benzylaminopurine, without charcoal. Callus cultures of Zataria multiflora were established from plantlets shoot nodes on MS supplemented with 1 mg L(-1) kinetin and 0.5 mg L(-1) 2, 4-dichlorophenoxyacetic acid. Callus growth rate on three different media (MS salts and vitamins, MS salts with Gamborg vitamins and Gamborg salts and vitamins) was evaluated. The best growth was recorded on Gamborg medium (salts and vitamins) with 0.75 mg L(-1) 6-benzylaminopurine and this medium was retained for rosmarinic acid production optimization experimentation. Sucrose and glucose were tested at different doses to compare the effect of carbohydrates on the growing rate and the production ofrosmarinic acid in shoot cultures and callus cultures. Experiments also were done at two light exposures (total obscurity or 16 h light/8 h dark). Very high level of rosmarinic acid was detected in callus tissues (158.26 mg g(-1) dry weight) as compared with propagated shoots (12.28 mg g(-1) dry weight). The dose of carbohydrate had a direct effect on the production of rosmarinic acid dependent of the type of tissues. The best ratio production/growth was obtained in callus cultures treated with glucose 75 g L(-1) under light exposure. These results indicate that, in Zataria multiflora, the undifferentiated state of tissues appears particularly more efficient for metabolic production in vitro, such as rosmarinic acid, in comparison to differentiated shoots. PMID:19090157

Françoise, Bernard; Hossein, Shaker; Halimeh, Hassanpoor; Zahra, Nejad Fallah

2007-10-01

165

A Novel Hybridization of Applied Mathematical, Operations Research and Risk-based Methods to Achieve an Optimal Solution to a Challenging Subsurface Contamination Problem  

NASA Astrophysics Data System (ADS)

The objective of the project is the creation of a new, computationally based, approach to the collection, evaluation and use of data for the purpose of determining optimal strategies for investment in the solution of remediation of contaminant source areas and similar environmental problems. The research focuses on the use of existing mathematical tools assembled in a unique fashion. The area of application of this new capability is optimal (least-cost) groundwater contamination source identification; we wish to identify the physical environments wherein it may be cost-prohibitive to identify a contaminant source, the optimal strategy to protect the environment from additional insult and formulate strategies for cost-effective environmental restoration. The computational underpinnings of the proposed approach encompass the integration into a unique of several known applied-mathematical tools. The resulting tool integration achieves the following: 1) simulate groundwater flow and contaminant transport under uncertainty, that is when the physical parameters such as hydraulic conductivity are known to be described by a random field; 2) define such a random field from available field data or be able to provide insight into the sampling strategy needed to create such a field; 3) incorporate subjective information, such as the opinions of experts on the importance of factors such as locations of waste landfills; 4) optimize a search strategy for finding a potential source location and to optimally combine field information with model results to provide the best possible representation of the mean contaminant field and its geostatistics. Our approach combines in a symbiotic manner methodologies found in numerical simulation, random field analysis, Kalman filtering, fuzzy set theory and search theory. Testing the algorithm for this stage of the work, we will focus on fabricated field situations wherein we can a priori specify the degree of uncertainty associated with the target locations and the field parameters. We will vary the uncertainty in these two factors to establish the relationship between the degree of uncertainty associated with them and the overall project costs. Of particular interest to us will be the sensitivity of the final determination of 'unidentifiable' and the various forms of uncertainty we enter into the experiments. By examining these test problems the algorithm can be refined and verified. The results of this research will show the accuracy and use of uncertainty in determining the source. The proposed research will seek to develop a new, computationally based, approach to the collection, evaluation and use of data for the purpose of determining optimal strategies for investment in the search for groundwater contamination sources. More specifically it will focus on those circumstances where it is economically infeasible to find a source or sources due to lack of know and field parameter uncertainty. The research will focus on the integration of several applied mathematical tools to achieve this objective. The resulting algorithm will be tested using fabricated, yet realistic field situations. The metric of success is whether the critical source of uncertainty in determining whether or not a source can be found is identifiable and its sensitivity.

Johnson, K. D.; Pinder, G. F.

2013-12-01

166

Expert meeting on Child Growth and Micronutrient Deficiencies--New Initiatives for Developing Countries to Achieve Millennium Development Goals: executive summary report.  

PubMed

Undernutrition in early childhood has long-term physical and intellectual consequences. Improving child growth should start before the age of two years and be an integrated effort between all sectors, covering all aspects such as diet and nutrient intake, disease reduction, optimum child care, and improved environmental sanitation. To discuss these issues, the Indonesian Danone Institute Foundation organized an expert meeting on Child Growth and Micronutrient Deficiencies: New Initiatives for Developing Countries to Achieve Millennium Development Goals. The objective of the meeting was to have a retrospective view on child growth: lessons learned from programs to overcome under-nutrition in the developed countries and to relate the situation to the Indonesian context, as well as to discuss implications for future programs. Recommendations derived from the meeting include focus intervention on the window of opportunity group, re-activation of the Integrated Health Post at the village level, improvement of infant and young child feeding, expand food fortification intervention programs, strengthen supplementation programs with multi-micronutrient, and strengthening public and private partnership on food related programs. PMID:19786396

Usfar, Avita A; Achadi, Endang L; Martorell, Reynaldo; Hadi, Hamam; Thaha, Razak; Jus'at, Idrus; Atmarita; Martianto, Drajat; Ridwan, Hardinsyah; Soekirman

2009-01-01

167

Achieving New Source Performance Standards (NSPS) Emission Standards Through Integration of Low-NOx Burners with an Optimization Plan for Boiler Combustion  

SciTech Connect

The objective of this project was to demonstrate the use of an Integrated Combustion Optimization System to achieve NO{sub X} emission levels in the range of 0.15 to 0.22 lb/MMBtu while simultaneously enabling increased power output. The project plan consisted of the integration of low-NO{sub X} burners and advanced overfire air technology with various process measurement and control devices on the Holcomb Station Unit 1 boiler. The plan included the use of sophisticated neural networks or other artificial intelligence technologies and complex software to optimize several operating parameters, including NO{sub X} emissions, boiler efficiency, and CO emissions. The program was set up in three phases. In Phase I, the boiler was equipped with sensors that can be used to monitor furnace conditions and coal flow to permit improvements in boiler operation. In Phase II, the boiler was equipped with burner modifications designed to reduce NO{sub X} emissions and automated coal flow dampers to permit on-line fuel balancing. In Phase III, the boiler was to be equipped with an overfire air system to permit deep reductions in NO{sub X} emissions. Integration of the overfire air system with the improvements made in Phases I and II would permit optimization of boiler performance, output, and emissions. This report summarizes the overall results from Phases I and II of the project. A significant amount of data was collected from the combustion sensors, coal flow monitoring equipment, and other existing boiler instrumentation to monitor performance of the burner modifications and the coal flow balancing equipment.

Wayne Penrod

2006-12-31

168

Post-traumatic growth and optimism as outcomes of an internet-based intervention for complicated grief.  

PubMed

This explorative study examines the effects of an internet-based cognitive-behavioural therapy for complicated grief on post-traumatic growth and optimism. The study is part of a larger randomized controlled trial described in Wagner, Knaevelsrud, and Maercker (2006). The patients were randomly assigned to either a treatment group (n = 26) or a waiting list control condition (n = 25). The internet-based intervention consisted of exposure to bereavement cues, cognitive reappraisal exercises, and a module on integration and restoration. A short form of the Post-traumatic Growth Inventory (PTGI), the Life Orientation Test-Revised (LOT-R), and measures of complicated grief and psychopathological outcomes were administered. Results indicate that post-traumatic growth increased in the treatment group. No treatment effect was found for optimism. These findings contribute to the growing literature on personal growth in psychotherapy. PMID:17852173

Wagner, Birgit; Knaevelsrud, Christine; Maercker, Andreas

2007-01-01

169

Growth Optimization of Metal-polar III-Nitride High-electron-mobility Transistor Structures by Molecular Beam Epitaxy  

NASA Astrophysics Data System (ADS)

GaN-based high-electron-mobility transistors (HEMTs) will play an important role in the next generation of high-frequency amplifiers and power-switching devices. Since parasitic conduction (leakage) through the GaN buffer layer and (Al,Ga,In)N barrier reduces the efficiency of operation, HEMT performance hinges on the epitaxial quality of these layers. Increasing the sheet charge density and mobility of the two-dimensional electron gas (2DEG) is also essential for reducing the channel resistance and improving output. The growth conditions applied in plasma-assisted molecular beam epitaxy (PAMBE) and ammonia-based molecular beam epitaxy (NH3-MBE) that result in high-quality metal-polar HEMT structures are described. The effects of threading dislocations on the gate leakage and channel conductivity of AlGaN/GaN HEMTs were studied in detail. For this purpose, a series of HEMT structures were grown on GaN templates with threading dislocation densities (TDDs) that spanned three orders of magnitude. There was a clear trend of reduced gate leakage with reduced TDD for HEMTs grown by Ga-rich PAMBE; however, a reduction in TDD also entailed an increase in buffer leakage. By reducing the unintentionally doped (UID) GaN buffer thickness and including an AlGaN back barrier, a HEMT regrown by Ga-rich PAMBE on low-TDD free-standing (FS) GaN (~5 x 107 cm-2 TDD) yielded a three-terminal breakdown voltage greater than 50 V and a power output (power-added efficiency) of 6.7 W/mm (50 %) at 4 GHz with a 40 V drain bias. High TDD was then shown to severely degrade the 2DEG mobility of AlxGa1-xN/GaN (x = 0.24, 0.12, 0.06) and AlGaN/AlN/GaN heterostructures grown by Ga-rich PAMBE. By regrowing on low-TDD FS GaN and including a 2.5 nm AlN interlayer, an Al0.24Ga0.76N/AlN/GaN heterostructure achieved a room temperature (RT) 2DEG sheet resistance of 169 ?/?. As evidenced by atom probe tomography, the AlN interlayer grown by Ga-rich PAMBE was pure with abrupt interfaces. The pure AlN interlayer greatly reduced alloy-related scattering. When AlGaN/AlN/GaN heterostructures were grown by NH3-MBE at 820 °C, the 2DEG sheet density was lower than expected. These AlN interlayers were shown to have a significant concentration of Ga impurities by atom probe tomography. The source of these impurities was most likely the decomposition of the underlying GaN layers, as reduction of the growth temperature below 750 °C yielded a much lower concentration of Ga impurities. Flux optimization and application of an In surfactant was necessary to reduce the interface roughness in AlGaN/AlN/GaN heterostructures grown by NH3-MBE at low temperature, yielding sheet resistances below 300 ?/?. The growth of InAlN/(GaN)/(AlN)/GaN heterostructures with lattice-matched In0.17Al0.83N barriers by N-rich PAMBE is also described. Through flux optimization, the columnar microstructure previously observed in N-rich PAMBE-grown InAlN layers was eliminated. By including a 3 nm AlN interlayer and 2 nm GaN interlayer, an In0.17Al0.83N/GaN/AlN/GaN heterostructure regrown on low-TDD FS GaN achieved an exceptionally low RT 2DEG sheet resistance of 145 ?/?.

Kaun, Stephen William

170

In situ growth optimization in focused electron-beam induced deposition  

PubMed Central

Summary We present the application of an evolutionary genetic algorithm for the in situ optimization of nanostructures that are prepared by focused electron-beam-induced deposition (FEBID). It allows us to tune the properties of the deposits towards the highest conductivity by using the time gradient of the measured in situ rate of change of conductance as the fitness parameter for the algorithm. The effectiveness of the procedure is presented for the precursor W(CO)6 as well as for post-treatment of Pt–C deposits, which were obtained by the dissociation of MeCpPt(Me)3. For W(CO)6-based structures an increase of conductivity by one order of magnitude can be achieved, whereas the effect for MeCpPt(Me)3 is largely suppressed. The presented technique can be applied to all beam-induced deposition processes and has great potential for a further optimization or tuning of parameters for nanostructures that are prepared by FEBID or related techniques. PMID:24367761

Weirich, Paul M; Winhold, Marcel; Huth, Michael

2013-01-01

171

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

172

Optimization of microencapsulated recombinant CHO cell growth, endostatin production, and stability of microcapsule in vivo.  

PubMed

Microencapsulation of recombinant cells secreting endostatin offers a promising approach to tumor gene therapy in which therapeutic protein is delivered in a sustainable and long-term fashion by encapsulated recombinant cells. However, the studies of cell growth and protein production in vivo are very limited. In this study, the effects of microencapsulation parameters on in vivo cell growth, endostatin production, and microcapsule stability after implantation in the peritoneal cavity of mice were for the first time investigated. Microcapsules with liquid core reached higher cell density and endostatin production at day 18 than microcapsules with solid core. There was no significant difference in stability whether the core of the microcapsule was solid or liquid. Decrease in microcapsule size increased the stability of microcapsule. The microcapsules kept intact in the peritoneal cavity of mice after 36 days of implantation when the microcapsules size was 240 microm in diameter, which gave rise to high endostatin production as well. The optimized microencapsulation conditions for in vivo implantation are liquid core and 240 microm in diameter. This study provides useful information for antiangiogenic gene therapy to tumors using microencapsulated recombinant cells. PMID:17497679

Zhang, Ying; Wang, Wei; Xie, Yubing; Yu, Weiting; Lv, Guojun; Guo, Xin; Xiong, Ying; Ma, Xiaojun

2008-01-01

173

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

PubMed Central

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

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

2009-01-01

174

GEOPHYSICAL RESEARCH LETTERS, VOL. ???, XXXX, DOI:10.1029/, Optimal Growth of Central and East Pacific ENSO Events1  

E-print Network

GEOPHYSICAL RESEARCH LETTERS, VOL. ???, XXXX, DOI:10.1029/, Optimal Growth of Central and East of Wisconsin - Madison, Madison, Wisconsin, USA. 2 Nelson Institute Center for Climatic Research, University of Wisconsin - Madison, Madison, Wisconsin, USA. 3 Physical Sciences Division, Earth System Research Laboratory

Newman, Matthew

175

Optimization of source-sink dynamics in plant growth for ideotype breeding: a case1 study on maize2  

E-print Network

of source-sink dynamics in plant growth for ideotype breeding: a case1 study on maize2 3 Rui QI ab* , Yuntao strategies3 with optimization guidance. As a test case, maize (Zea mays L., DEA cultivar), which4 is one-yield maize, especially in the current21 agricultural context and the increasing importance of co

Boyer, Edmond

176

Optimization of Magnetosome Production and Growth by the Magnetotactic Vibrio Magnetovibrio blakemorei Strain MV-1 through a Statistics-Based Experimental Design  

PubMed Central

The growth and magnetosome production of the marine magnetotactic vibrio Magnetovibrio blakemorei strain MV-1 were optimized through a statistics-based experimental factorial design. In the optimized growth medium, maximum magnetite yields of 64.3 mg/liter in batch cultures and 26 mg/liter in a bioreactor were obtained. PMID:23396329

Silva, Karen T.; Leão, Pedro E.; Abreu, Fernanda; López, Jimmy A.; Gutarra, Melissa L.; Farina, Marcos; Bazylinski, Dennis A.; Freire, Denise M. G.

2013-01-01

177

X-ray diffraction study of the optimization of MgO growth conditions for magnetic tunnel junctions  

SciTech Connect

We have carried out a systematic study optimizing the MgO growth via preparation and sputtering conditions and underlayer structures. It was found that to prevent water vapor which is detrimental to MgO (200) growth, the chamber pressure needs to be reduced below 10{sup -8} Torr. Simple underlayers such as 5 nm CoFeB tend to give better MgO, but we have also succeeded in growing MgO on more complicated underlayers such as 1 Ta/20 Au/5 Co{sub 40}Fe{sub 40}B{sub 20} and 1 Ta/20 conetic (Ni{sub 77}Fe{sub 14}Cu{sub 5}Mo{sub 4})/1.5 Co{sub 40}Fe{sub 40}B{sub 20} (units in nanometers). We accomplished this by extensive baking of the deposition chamber and use of Ti-getter films. Short sputtering distance and high sputtering power were found to optimize MgO deposition. We found that both preparation and sputtering conditions have important effects on the MgO growth. X-ray diffraction analysis was used as the characterization tool for optimizing the MgO growth conditions.

O, Se Young [Magnetic Materials Group, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); School of Nano and Advanced Materials Engineering, Changwon National University, 9 Sarim-dong, Changwon, Gyeongnam 641-773 (Korea, Republic of); Lee, Chan-Gyu [School of Nano and Advanced Materials Engineering, Changwon National University, 9 Sarim-dong, Changwon, Gyeongnam 641-773 (Korea, Republic of); Shapiro, Alexander J.; Egelhoff, William F. Jr.; Mallett, Jonathan; Pong, Philip W. T. [Magnetic Materials Group, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Vaudin, Mark D.; Ruglovsky, Jennifer L. [Ceramic Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

2008-04-01

178

Enhanced growth and lipid accumulation by a new Ettlia texensis isolate under optimized photoheterotrophic condition.  

PubMed

A green microalgae, named as Ettlia texensis was obtained from local freshwater in Turkey. The effects of autotrophic, photoheterotrophic and heterotrophic cultivations on biomass and lipid production were studied. Searching the preferences of the carbon and nitrogen source revealed that this strain could grow photoheterotrophically well with glucose and yeast extract. In the optimized medium, the highest biomass productivity and total lipid content achieved were 0.97 g/L d and 26% of dry weight basis, respectively. Moreover, the major fatty acid methyl esters were C16:0; C18:1; C18:2 and C18:3. In a scale-up attempt, productions were accomplished in a 3 L stirred tank bioreactor. The final biomass and lipid productivities obtained in bioreactor with 250 rpm agitation rate were 0.92 g/L d and 322 mg/L d, respectively. The biochemical compositions were monitored simultaneously by the FTIR spectroscopy during the production in bioreactor. E. texensis could be potent candidate for commercial production in the bioreactor photoheterotrophically. PMID:23353038

Isleten-Hosoglu, Muge; Ayy?ld?z-Tamis, Duygu; Zengin, Gokhan; Elibol, Murat

2013-03-01

179

A Novel Liquid Medium for the Efficient Growth of the Salmonid Pathogen Piscirickettsia salmonis and Optimization of Culture Conditions  

PubMed Central

Piscirickettsia salmonis is the bacterium that causes Piscirickettsiosis, a systemic disease of salmonid fish responsible for significant economic losses within the aquaculture industry worldwide. The growth of the bacterium for vaccine formulation has been traditionally accomplished by infecting eukaryotic cell lines, a process that involves high production costs and is time-consuming. Recent research has demonstrated that it is possible to culture pure P. salmonis in a blood containing (cell-free) medium. In the present work we demonstrate the growth of P. salmonis in a liquid medium free from blood and serum components, thus establishing a novel and simplified bacteriological medium. Additionally, the new media reported provides improved growth conditions for P. salmonis, where biomass concentrations of approximately 800 mg cell dry weight L?1 were obtained, about eight times higher than those reported for the blood containing medium. A 2- level full factorial design was employed to evaluate the significance of the main medium components on cell growth and an optimal temperature range of 23–27°C was determined for the microorganism to grow in the novel liquid media. Therefore, these results represent a breakthrough regarding P. salmonis research in order to optimize pure P. salmonis growth in liquid blood and serum free medium. PMID:24039723

Marshall, Sergio H.; Henríquez, Vitalia; Gómez, Fernando A.; Martínez, Irene; Altamirano, Claudia

2013-01-01

180

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

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…

Shin, Tacksoo

2012-01-01

181

Screening and Optimization of Indole3Acetic Acid Production and Phosphate Solubilization from Rhizobacteria Aimed at Improving Plant Growth  

Microsoft Academic Search

A total of 216 bacterial strains were isolated from rice rhizospheric soils in Northern Thailand. The bacterial strains were\\u000a initially tested for solubilization of inorganic phosphate, indole acetic acid (IAA) production, selected strains were then\\u000a tested for optimized conditions for IAA production and whether these caused stimulatory effects on bean and maize seedling\\u000a growth. It was found that all strains

Mathurot Chaiharn; Saisamorn Lumyong

2011-01-01

182

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

PubMed Central

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

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

2014-01-01

183

Growth of fully doped Hg1-xCdxTe heterostructures using a novel iodine doping source to achieve improved device performance at elevated temperatures  

NASA Astrophysics Data System (ADS)

Band gap engineered Hg1-xCdxTe (MCT) heterostructures should lead to detectors with improved electro-optic and radiometric performance at elevated operating temperatures. Growth of such structures was accomplished using metalorganic vapor phase epitaxy (MOVPE). Acceptor doping with arsenic (As), using phenylarsine (PhAsH2), demonstrated 100% activation and reproducible control over a wide range of concentrations (1 × 1015 to 3.5 × 1017 cm-3). Although vapor from elemental iodine showed the suitability of iodine as a donor in MC.T, problems arose while controlling low donor concentrations. Initial studies using ethyliodide (EtI) demonstrated that this source could be used successfully to dope MCT, yielding the properties required for stable heterostructure devices, i.e. ?100% activation, no memory problems and low diffusion coefficient. Cryogenic alkyl cooling or very high dilution factors were required to achieve the concentrations needed for donor doping below ?1016cm-3 due to the high vapor pressure of the alkyl. A study of an alternative organic iodide source, 2-methylpropyliodide (2 MePrI), which has a much lower vapor pressure, improved control of low donor concentrations. 2 MePrI demonstrated the same donor source suitability as EtI and was used to control iodine concentrations from ? 1 × 1015 to 5 × 1017cm-3. The iodine from both sources only incorporated during the CdTe cycles of the interdiffused multilayer process (IMP) in a similar manner to both elemental iodine and As from PhAsH2. High resolution secondary ion mass spectroscopy analysis showed that IMP scale modulations can still be identified after growth. The magnitude of these oscillations is consistent with a diffusion coefficient of?7 × 10-16cm2s-1 for iodine in MC.T at 365°C. Extrinsically doped device heterostructures, grown using 2 MePrI, have been intended to operate at elevated temperatures either for long wavelength (8 12 smm) equilibrium operation at 145K or nonequilibrium operation at 190 and 295K in both the 3 5 µ and 8 12 µ wavelength ranges. Characterization of such device structures will be discussed. Linear arrays of mesa devices have been fabricated in these layers. Medium wave nonequilibrium device structures have demonstrated high quantum efficiencies and R0A = 37 ?cm2 for ?co = 4.9 µ at 190K.

Maxey, C. D.; Jones, C. L.; Metcalfe, N. E.; Catchpole, R.; Houlton, M. R.; White, A. M.; Gordon, N. T.; Elliott, C. T.

1996-08-01

184

Utilizing of protein splicing phenomenon for optimization of obtaining and purification of the recombinant human growth hormone  

E-print Network

Protein splicing is a post-translational autocatalystic excision of internal protein sequence (intein) with the subsequent ligation of the flanking polypeptides (exteins). The high specificity of excision ensured by intein makes it possible to use a phenomenon of protein splicing for the biotechnology purposes. The aim of this work was optimization of obtaining and purification of the recombinant human growth hormone using the protein splicing. It was experimentally demonstrated that the use of modified intein as auto-removal affine marker makes it possible to perform the rapid and cheap isolation of the recombinant protein Hgh. Furthermore, this approach allows to obtain the human growth hormone with native N-terminus, without formyl-metionine. Key words: intein, human growth hormone, protein splicing

P. L. Starokadomskyy; O. V. Okunev; L. V. Dubey

2006-12-05

185

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

NASA Astrophysics Data System (ADS)

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 lunar regolith to form a critical reactor assembly. The regolith would not just provide radiation shielding, but serve as neutron-reflector material as well. The reactor subunits are to be manufactured using proven and tested materials for use in radiation environments, such as uranium-dioxide fuel, stainless-steel cladding and structural support, and liquid-sodium heatpipes. The LEGO Reactor system promotes reliability, safety, and ease of manufacture and testing at the cost of an increase in launch mass per overall rated power level and a reduction in neutron economy when compared to a single-reactor system. A single unshielded LEGO Reactor subunit has an estimated mass of approximately 448 kg and provides 5 kWe using a free-piston Stirling space converter. The overall envelope for a single unit with fully extended radiator panels has a height of 8.77 m and a diameter of 0.50 m. The subunits can be placed with centerline distances of approximately 0.6 m in a hexagonal-lattice pattern to provide sufficient neutronic coupling while allowing room for heat rejection and interstitial control. A lattice of six subunits could provide sufficient power generation throughout the initial stages of establishing a lunar outpost. Portions of the reactor may be neutronically decoupled to allow for reduced power production during unmanned periods of base operations. During later stages of lunar-base development, additional subunits may be emplaced and coupled into the existing LEGO Reactor network Future improvements include advances in reactor control methods, fuel form and matrix, determination of shielding requirements, as well as power conversion and heat rejection techniques to generate an even more competitive LEGO Reactor design. Further modifications in the design could provide power generative opportunities for use on other extraterrestrial surfaces such as Mars, other moons, and asteroids.

Bess, John Darrell

186

Optimization of growth conditions of Lentinus edodes mycelium on corn processing waste using response surface analysis.  

PubMed

This research was conducted to evaluate the use of corn processing waste as an alternative growth medium for the cultivation of Lentinus edodes mycelium and to determine the optimum growth conditions under solid-state cultivation. The substrate concentration, pH, and temperature for maximizing the growth rate of L. edodes mycelium, 9.3+/-0.6 mm/d, were 44.3 g/l, 4.7, and 24.7 degrees C, respectively. Therefore, the results suggest that corn processing waste can be utilized as a growth substrate for cultivating L. edodes mycelium. PMID:18343345

Lee, Seungyong; Bae, Hyokwan; Kim, Nakyung; Hwang, Seokhwan

2008-02-01

187

CHANGE DETECTION -CELLULAR AUTOMATA METHOD FOR URBAN GROWTH MODELING  

E-print Network

CHANGE DETECTION - CELLULAR AUTOMATA METHOD FOR URBAN GROWTH MODELING Sharaf Alkheder, Jun Wang in the algorithm drive the urban growth over time. Calibration is introduced in the cellular automata model the optimal values for the transition rules to achieve accurate urban growth modeling. The paper discusses

Shan, Jie

188

The optimal level of balanced protein for growth in females between 20 and 50 kg body weight could not be determined due to a linear straight relationship between growth perfor-  

E-print Network

The optimal level of balanced protein for growth in females between 20 and 50 kg body weight could not be determined due to a linear straight relationship between growth perfor- mance and protein level, after supplementation with lysine (13 and 15 p. 100 protein). Any way it may be excepted that this level is slightly

Paris-Sud XI, Université de

189

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

Microsoft Academic Search

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

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

2009-01-01

190

Ecological Optimism in the Social Sciences: The Question of Limits to Growth.  

ERIC Educational Resources Information Center

Reviews various social science models of man designed to explain the issue of limits to growth for human societies. Presents arguments often advanced by proponents of pessimistic and optimistic schools of thought regarding whether society will be successfully able to deal with the limits to growth controversy. (Author/DB)

Luten, Daniel B.

1980-01-01

191

Optimization of Computational Neural Network for Its Application in the Prediction of Microbial Growth in Foods  

Microsoft Academic Search

The power of computational neural networks (CNN) for microbiological growth prediction was evaluated. The training set consisted of growth responses data from a combination of three strains of Salmonella in a laboratory medium as affected by pH level, sodium chloride concentration and storage temperature. The architecture of CNN was designed to contain three input parameters in the input layer and

C. Hervs; G. Zurera; R. M. Garcfa; J. A. Martinez

2001-01-01

192

Achieving Sustainable Growth through the Adoption of Integrated Business and Information Solutions: A Case Study of Nigerian Small & Medium Sized Enterprises  

Microsoft Academic Search

The economic growth of any country depends, to a certain degree, on the ability of the country's business community to maximize their growth potential. One of the biggest contributors from the business community of any nation, to the nation's economic development, is the small and medium sized enterprise (SME) sector. Studies have shown that SMEs and indeed, large and multi-national

193

Low high-density lipoprotein cholesterol is a residual risk factor associated with long-term clinical outcomes in diabetic patients with stable coronary artery disease who achieve optimal control of low-density lipoprotein cholesterol.  

PubMed

Diabetes mellitus is recognized an independent risk factor for coronary artery disease (CAD) and mortality. Clinical trials have shown that statins significantly reduce cardiovascular events in diabetic patients. However, residual cardiovascular risk persists despite the achievement of target low-density lipoprotein cholesterol (LDL-C) levels with statin. High-density lipoprotein cholesterol (HDL-C) is an established coronary risk factor that is independent of LDL-C levels. We evaluated the impact of HDL-C on long-term mortality in diabetic patients with stable CAD who achieved optimal LDL-C. We enrolled 438 consecutive diabetic patients who were scheduled for percutaneous coronary intervention between 2004 and 2007 at our institution. We identified 165 patients who achieved target LDL-C <100 mg/dl. Patients were stratified into two groups according to HDL-C levels (low HDL-C group, baseline HDL-C <40 mg/dl; high HDL-C group, ?40 mg/dl). Major adverse cardiac events (MACE) that included all-cause death, acute coronary syndrome, and target lesion revascularization were evaluated between the two groups. The median follow-up period was 946 days. The rate of MACE was significantly higher in diabetic patients with low-HDL-C who achieved optimal LDL-C (6.9 vs 17.9 %, log-rank P = 0.030). Multivariate Cox regression analysis showed that HDL-C is significantly associated with clinical outcomes (adjusted hazard ratio for MACE 1.33, 95 % confidence interval 1.01-1.75, P = 0.042). Low HDL-C is a residual risk factor that is significantly associated with long-term clinical outcomes among diabetic patients with stable CAD who achieve optimal LDL-C levels. PMID:23516028

Ogita, Manabu; Miyauchi, Katsumi; Miyazaki, Tadashi; Naito, Ryo; Konishi, Hirokazu; Tsuboi, Shuta; Dohi, Tomotaka; Kasai, Takatoshi; Yokoyama, Takayuki; Okazaki, Shinya; Kurata, Takeshi; Daida, Hiroyuki

2014-01-01

194

Optimizing Epitaxial Cu and Ni Films on Al2O3(0001) for Uniform Graphene Growth  

NASA Astrophysics Data System (ADS)

Copper and nickel are the most commonly used substrates for the growth of graphene by chemical vapor deposition. While cold-rolled polycrystalline foils are most often selected for their commercial availability and ability to withstand the high temperatures required for graphene growth, (111) crystal faces have been shown to offer better growth characteristics on both materials. We deposited Cu and Ni films onto single crystal Al2O3(0001) using magnetron sputtering at temperatures between 250 ^oC and 700 ^oC. This gave films with pure (111) texture but with two epitaxial in-plane orientations as measured by x-ray diffraction and electron backscatter diffraction. Upon heating to graphene CVD temperatures (900 ^oC to 1000 ^oC), the grain boundaries widen and deepen into trenches that prevent the growth of uniform graphene over large areas. Reactive sputtering of a thin layer of Al2O3 before depositing the metal results in a single in-plane orientation over >90% of the film for Ni. In addition, gradually increasing the temperature during metal deposition suppresses the formation of deep trenches under graphene CVD conditions. We compare CVD graphene grown on the optimized films with that grown on commercial foils.

Miller, David L.; Keller, Mark W.; Keller, Robert R.; Shaw, Justin M.; Chiaramonti, Ann N.

2012-02-01

195

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

E-print Network

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 ...

Steiner, Stephen Alan, III

2006-01-01

196

Influence of hydrodynamic conditions on growth and geometry of anodic TiO 2 nanotubes and their use towards optimized DSSCs  

Microsoft Academic Search

In the present work we grow anodic TiO 2 nanotube layers under defined hydrodynamic conditions using a rotating Ti anode. We show that hydrodynamic control can be beneficially used to achieve two main effects. First, under conditions where tube growth is controlled by diffusion (for low concentration of fluoride ions in the electrolyte), growth can significantly be accelerated (or even

R. a c Sánchez-Tovar; I. b Paramasivam; K. b Lee; P.b Schmuki

2012-01-01

197

Modeling of Fusarium redolens Dzf2 mycelial growth kinetics and optimal fed-batch fermentation for beauvericin production.  

PubMed

Beauvericin (BEA) is a cyclic hexadepsipeptide mycotoxin with notable phytotoxic and insecticidal activities. Fusarium redolens Dzf2 is a highly BEA-producing fungus isolated from a medicinal plant. The aim of the current study was to develop a simple and valid kinetic model for F. redolens Dzf2 mycelial growth and the optimal fed-batch operation for efficient BEA production. A modified Monod model with substrate (glucose) and product (BEA) inhibition was constructed based on the culture characteristics of F. redolens Dzf2 mycelia in a liquid medium. Model parameters were derived by simulation of the experimental data from batch culture. The model fitted closely with the experimental data over 20-50 g l(-1) glucose concentration range in batch fermentation. The kinetic model together with the stoichiometric relationships for biomass, substrate and product was applied to predict the optimal feeding scheme for fed-batch fermentation, leading to 54% higher BEA yield (299 mg l(-1)) than in the batch culture (194 mg l(-1)). The modified Monod model incorporating substrate and product inhibition was proven adequate for describing the growth kinetics of F. redolens Dzf2 mycelial culture at suitable but not excessive initial glucose levels in batch and fed-batch cultures. PMID:21082211

Xu, Li-Jian; Liu, Yuan-Shuai; Zhou, Li-Gang; Wu, Jian-Yong

2011-09-01

198

Optimization of acidic fibroblast growth factor (FGF-1) and its delivery through a modified degradable fibrin scaffold  

NASA Astrophysics Data System (ADS)

The aim of this investigation was to develop a degradable fibrin wound dressing that can deliver an optimized dose of acidic fibroblast growth factor (FGF-1). This aim led to three distinct phases of study. In the first phase, a structurally modified fibrin degradable scaffold was developed and tested in a rabbit ear ulcer model. A significant increase in the angiogenic and fibroblastic response with a corresponding decrease in healing time was seen in the modified fibrin-treated ulcers as compared with untreated ulcers and ulcers treated with non-modified fibrin systems. In the second phase of the study, a biochemical factor, FGF-1, was added to this scaffold. An optimal dose of 8 mug of FGF-1 was determined to be required to initiate a desired wound-healing response in a rabbit ear ulcer model, based on an enhanced angiogenic and fibroblastic response and an increased epithelialization rate. The objective of the last phase was to investigate the efficacy of a modified scaffold as a vehicle for FGF-1. In vivo testing was conducted in a full-thickness defect model in a rabbit. Improvements were seen in the angiogenic and fibroblastic responses in the FGF-1/modified fibrin treatment group and, hence, FGF-1/modified fibrin was the preferred treatment. In conclusion, the modified fibrin/FGF-1 matrix served as a suitable vehicle for the growth factor, providing a desired healing response and a desirable release rate and, thus, was determined to be an effective scaffold.

Pandit, Abhay Smashikant

199

Platelet-rich plasma preparation for regenerative medicine: optimization and quantification of cytokines and growth factors  

PubMed Central

Introduction Platelet-rich plasma (PRP) is nowadays widely applied in different clinical scenarios, such as orthopedics, ophthalmology and healing therapies, as a growth factor pool for improving tissue regeneration. Studies into its clinical efficiency are not conclusive and one of the main reasons for this is that different PRP preparations are used, eliciting different responses that cannot be compared. Platelet quantification and the growth factor content definition must be defined in order to understand molecular mechanisms behind PRP regenerative strength. Standardization of PRP preparations is thus urgently needed. Methods PRP was prepared by centrifugation varying the relative centrifugal force, temperature, and time. Having quantified platelet recovery and yield, the two-step procedure that rendered the highest output was chosen and further analyzed. Cytokine content was determined in different fractions obtained throughout the whole centrifugation procedure. Results Our method showed reproducibility when applied to different blood donors. We recovered 46.9 to 69.5% of total initial platelets and the procedure resulted in a 5.4-fold to 7.3-fold increase in platelet concentration (1.4 × 106 to 1.9 × 106 platelets/?l). Platelets were highly purified, because only <0.3% from the initial red blood cells and leukocytes was present in the final PRP preparation. We also quantified growth factors, cytokines and chemokines secreted by the concentrated platelets after activation with calcium and calcium/thrombin. High concentrations of platelet-derived growth factor, endothelial growth factor and transforming growth factor (TGF) were secreted, together with the anti-inflammatory and proinflammatory cytokines interleukin (IL)-4, IL-8, IL-13, IL-17, tumor necrosis factor (TNF)-? and interferon (IFN)-?. No cytokines were secreted before platelet activation. TGF-?3 and IFN? were not detected in any studied fraction. Clots obtained after platelet coagulation retained a high concentration of several growth factors, including platelet-derived growth factor and TGF. Conclusions Our study resulted in a consistent PRP preparation method that yielded a cytokine and growth factor pool from different donors with high reproducibility. These findings support the use of PRP in therapies aiming for tissue regeneration, and its content characterization will allow us to understand and improve the clinical outcomes. PMID:23759113

2013-01-01

200

Growth in serum-free medium of human colonic adenocarcinoma cell lines on microcarriers: a two-step method allowing optimal cell spreading and growth.  

PubMed

Human colonic adenocarcinoma cells have been successfully grown on polystyrene microcarriers by modifying the culture conditions used in monolayer culture. The method can be divided into two culture phases: a) a phase of spreading, wherein cells were seeded in presence of serum-supplemented medium; b) a phase of active growth wherein spread cells on the beads were allowed to grow in a serum-free medium. Under these conditions, optimal spreading and growth of HT 29 and HRT 18 cells on the microcarriers were obtained. A differential propagation was observed between HT 29-D4 and HT 29-D9 cells (both clonal populations derived from HT 29 cells) on the microcarriers that is tentatively related to the discrepancy observed in the spreading efficiency of these clonal cells on serum-coated culture flasks. An index of spreading efficiency (IS index) has been defined to quantify the efficiency of spreading of each cell line on microcarriers. These data gave the opportunity to develop serum-free, scale-up methods to culture cells like HT 29 which release potentially useful products. PMID:3654483

Fantini, J; Galons, J P; Abadie, B; Canioni, P; Cozzone, P J; Marvaldi, J; Tirard, A

1987-09-01

201

Modeling within-season sugarcane growth for optimal harvest system selection  

Microsoft Academic Search

The recent switch from wholestalk to combine sugarcane harvesters has raised questions concerning which harvester is more profitable. Combine harvesters recovery more of the sugarcane in the field than wholestalk harvesters, but also have higher trash levels reducing sucrose recovery. The objective of the research presented in this article is to determine the optimal sugarcane harvest system selection for sugarcane

M. E. Salassi; J. B. Breaux; C. J. Naquin

2002-01-01

202

Growth condition optimization for docosahexaenoic acid (DHA) production by Moritella marina MP-1.  

PubMed

The marine organism Moritella marina MP-1 produces the polyunsaturated fatty acid docosahexaenoic acid (DHA). While the basic metabolic pathway for DHA production in this organism has been identified, the impact of growth conditions on DHA production is largely unknown. This study examines the effect of supplemental carbon, nitrogen and salts, growth temperature and media composition and pH on DHA and biomass production and the fatty acid profile. The addition of supplemental nitrogen significantly increased the overall DHA titer via an increase in biomass production. Supplemental glucose or glycerol increased biomass production, but decreased the amount of DHA per biomass, resulting in no net change in the DHA titer. Acidification of the baseline media pH to 6.0 increased DHA per biomass. Changes in growth temperature or provision of supplemental sodium or magnesium chloride did not increase DHA titer. This organism was also shown to grow on defined minimal media. For both media types, glycerol enabled more DHA production per biomass than glucose. Combination of these growth findings into marine broth supplemented with glycerol, yeast extract, and tryptone at pH?6.0 resulted in a final titer of 82±5 mg/L, a nearly eightfold increase relative to the titer of 11±1 mg/L seen in the unsupplemented marine broth. The relative distribution of other fatty acids was relatively robust to growth condition, but the presence of glycerol resulted in a significant increase in myristic acid (C14:0) and decrease in palmitic acid (C16:0). In summary, DHA production by M. marina MP-1 can be increased more than fivefold by changing the growth media. Metabolic engineering of this organism to increase the amount of DHA produced per biomass could result in additional increases in titer. PMID:23111600

Kautharapu, Kumar B; Rathmacher, John; Jarboe, Laura R

2013-04-01

203

Enhancement of lipid productivity in oleaginous Colletotrichum fungus through genetic transformation using the yeast CtDGAT2b gene under model-optimized growth condition.  

PubMed

Oleaginous fungi are of special interest among microorganisms for the production of lipid feedstocks as they can be cultured on a variety of substrates, particularly waste lingocellulosic materials, and few fungal strains are reported to accumulate inherently higher neutral lipid than bacteria or microalgae. Previously, we have characterized an endophytic filamentous fungus Colletotrichum sp. DM06 that can produce total lipid ranging from 34% to 49% of its dry cell weight (DCW) upon growing with various carbon sources and nutrient-stress conditions. In the present study, we report on the genetic transformation of this fungal strain with the CtDGAT2b gene, which encodes for a catalytically efficient isozyme of type-2 diacylglycerol acyltransferase (DGAT) from oleaginous yeast Candida troplicalis SY005. Besides the increase in size of lipid bodies, total lipid titer by the transformed Colletotrichum (lipid content ?73% DCW) was found to be ?1.7-fold more than the wild type (lipid content ?38% DCW) due to functional activity of the CtDGAT2b transgene when grown under standard condition of growth without imposition of any nutrient-stress. Analysis of lipid fractionation revealed that the neutral lipid titer in transformants increased up to 1.8-, 1.6- and 1.5-fold compared to the wild type when grown under standard, nitrogen stress and phosphorus stress conditions, respectively. Lipid titer of transformed cells was further increased to 1.7-fold following model-based optimization of culture conditions. Taken together, ?2.9-fold higher lipid titer was achieved in Colletotrichum fungus due to overexpression of a rate-limiting crucial enzyme of lipid biosynthesis coupled with prediction-based bioprocess optimization. PMID:25375973

Dey, Prabuddha; Mall, Nikunj; Chattopadhyay, Atrayee; Chakraborty, Monami; Maiti, Mrinal K

2014-01-01

204

Optimization of power control in the reduction of basal plane dislocations during PVT growth of 4H-SiC single crystals  

NASA Astrophysics Data System (ADS)

The influence of power control on the multiplication of basal plane dislocations (BPDs) during PVT growth of 4H-SiC single crystals was studied by numerical modeling. Three sets of different power histories during growth were tested: continuously increasing power, continuously decreasing power, and constant power. The results show that optimization of the power history control is crucial for the reduction of basal plane dislocations during growth. If only low BPD density is concerned, then constant low power is the best choice. However, if both low BPD density and high growth rate are desirable, then concave continuously increasing power is the best choice.

Gao, B.; Kakimoto, K.

2014-04-01

205

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

Microsoft Academic Search

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

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

2005-01-01

206

Private Incentives versus Class Interests: A Theory of Optimal Institutions with An Application to Growth  

Microsoft Academic Search

We build a dynamic political economy model with a two-class society: workers and the elite. A key feature of the model is that the formation of the elite, the rate of innovation, taxes and public spending are endogenous. Differently from most of the literature on institutions and growth which emphasizes the conflict between different classes, we focus on the tension

Ani Guerdjikova; Levon Barseghyan

2008-01-01

207

Different levels of catabolite repression optimize growth in stable and variable environments.  

PubMed

Organisms respond to environmental changes by adapting the expression of key genes. However, such transcriptional reprogramming requires time and energy, and may also leave the organism ill-adapted when the original environment returns. Here, we study the dynamics of transcriptional reprogramming and fitness in the model eukaryote Saccharomyces cerevisiae in response to changing carbon environments. Population and single-cell analyses reveal that some wild yeast strains rapidly and uniformly adapt gene expression and growth to changing carbon sources, whereas other strains respond more slowly, resulting in long periods of slow growth (the so-called "lag phase") and large differences between individual cells within the population. We exploit this natural heterogeneity to evolve a set of mutants that demonstrate how the frequency and duration of changes in carbon source can favor different carbon catabolite repression strategies. At one end of this spectrum are "specialist" strategies that display high rates of growth in stable environments, with more stringent catabolite repression and slower transcriptional reprogramming. The other mutants display less stringent catabolite repression, resulting in leaky expression of genes that are not required for growth in glucose. This "generalist" strategy reduces fitness in glucose, but allows faster transcriptional reprogramming and shorter lag phases when the cells need to shift to alternative carbon sources. Whole-genome sequencing of these mutants reveals that mutations in key regulatory genes such as HXK2 and STD1 adjust the regulation and transcriptional noise of metabolic genes, with some mutations leading to alternative gene regulatory strategies that allow "stochastic sensing" of the environment. Together, our study unmasks how variable and stable environments favor distinct strategies of transcriptional reprogramming and growth. PMID:24453942

New, Aaron M; Cerulus, Bram; Govers, Sander K; Perez-Samper, Gemma; Zhu, Bo; Boogmans, Sarah; Xavier, Joao B; Verstrepen, Kevin J

2014-01-01

208

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

PubMed Central

Organisms respond to environmental changes by adapting the expression of key genes. However, such transcriptional reprogramming requires time and energy, and may also leave the organism ill-adapted when the original environment returns. Here, we study the dynamics of transcriptional reprogramming and fitness in the model eukaryote Saccharomyces cerevisiae in response to changing carbon environments. Population and single-cell analyses reveal that some wild yeast strains rapidly and uniformly adapt gene expression and growth to changing carbon sources, whereas other strains respond more slowly, resulting in long periods of slow growth (the so-called “lag phase”) and large differences between individual cells within the population. We exploit this natural heterogeneity to evolve a set of mutants that demonstrate how the frequency and duration of changes in carbon source can favor different carbon catabolite repression strategies. At one end of this spectrum are “specialist” strategies that display high rates of growth in stable environments, with more stringent catabolite repression and slower transcriptional reprogramming. The other mutants display less stringent catabolite repression, resulting in leaky expression of genes that are not required for growth in glucose. This “generalist” strategy reduces fitness in glucose, but allows faster transcriptional reprogramming and shorter lag phases when the cells need to shift to alternative carbon sources. Whole-genome sequencing of these mutants reveals that mutations in key regulatory genes such as HXK2 and STD1 adjust the regulation and transcriptional noise of metabolic genes, with some mutations leading to alternative gene regulatory strategies that allow “stochastic sensing” of the environment. Together, our study unmasks how variable and stable environments favor distinct strategies of transcriptional reprogramming and growth. PMID:24453942

New, Aaron M.; Cerulus, Bram; Govers, Sander K.; Perez-Samper, Gemma; Zhu, Bo; Boogmans, Sarah; Xavier, Joao B.; Verstrepen, Kevin J.

2014-01-01

209

New and Expanded Concepts in Neurophysiology, Psychology, and Sociology Complementary to Llorens' Developmental Theory: Achieving Growth and Development through Occupation for Neonatal Infants and their Families  

Microsoft Academic Search

Introduction: This issue expands the Llorens’ Developmental Theory of Occupational Therapy. Llorens drew from multiple theorists from the disciplines of sociology, neurophysiology, biology, ecology, psychology, occupational science, and psychodynamics to provide the profession of occupational therapy with a unified theory to facilitate growth and development for people of all ages—from infancy to old age.Purpose: The purpose of this issue is

Lynne F. La Corte

2008-01-01

210

Where Have All the Good Men Gone?: An Analysis of Gender Differences in Achievement Growth in Eighth and Ninth Grade Math  

ERIC Educational Resources Information Center

The growing epidemic of male underachievement has spawned a great deal of research in the recent past. This body of research has been inconclusive in determining the causes of the problem. This Capstone Project looked at six factors to determine if any of them had a significant effect on the math achievement of either gender. This study was…

Plue, Kevin Eric

2011-01-01

211

Family and Contextual Socioeconomic Effects across Seasons: When Do They Matter for the Achievement Growth of Young Children? WCER Working Paper No. 2007-5, August 2007  

ERIC Educational Resources Information Center

Researchers have disagreed about the extent to which differences in achievement based on socioeconomic status (SES) accumulate during the school year as compared to the summer, and the literature has not fully assessed the contributions of social contexts--in the form of both school and neighborhood poverty concentration and racial and ethnic…

Benson, James G.; Borman, Geoffrey D.

2007-01-01

212

Late Immersion and Language of Instruction (English vs. Chinese) in Hong Kong High Schools: Achievement Growth in Language and Nonlanguage Subjects.  

ERIC Educational Resources Information Center

This study examines how instruction in the first language (L1), Chinese, and in the second language (L2), English, affects a large sample of students' academic achievement in L1, L2, and content, nonlanguage school subjects, including mathematics, science, geography, and history, in their first 3 years of high school. For all four content area…

Hau, Kit-Tai; Marsh, Herbert W.; Kong, Chit-Kwong; Poon, Andrew Chung-Shing

213

Reading Achievement across Three Language Groups: Growth Estimates for Overall Reading and Reading Subskills Obtained with the Early Childhood Longitudinal Survey  

ERIC Educational Resources Information Center

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…

Roberts, Greg; Mohammed, Sarojani S.; Vaughn, Sharon

2010-01-01

214

The role of thermophysics in the design, optimization and understanding of semiconductor crystal growth in space  

NASA Technical Reports Server (NTRS)

The compound semiconductor material PbSnTe has been investigated by NASA Langley Research Center as part of the Material Processing in Space (MPS) experiment in the framework of the Space Shuttle program. The long-range goal of the research is the improving of the performance of infrared detectors for use in remote sensing experiments. Three distinct techniques will be used in the low-g environment of space: two techniques involving bulk growth from melt and a vapor growth technique. In order to establish realistic estimates of the required time for experiments and to determine the thermal gradients that will be required to avoid constitutional supercooling, the diffusion coefficients must be accurately measured, however more data especially in the vapor-solid phase relations are needed.

Crouch, R. K.; Fripp, A. L.; Debnam, W. J.; Clark, I. O.

1979-01-01

215

Optimization of flow assisted entrapment of pollen grains in a microfluidic platform for tip growth analysis.  

PubMed

A biocompatible polydimethylsiloxane (PDMS) biomicrofluidic platform is designed, fabricated and tested to study protuberance growth of single plant cells in a micro-vitro environment. The design consists of an inlet to introduce the cell suspension into the chip, three outlets to conduct the medium or cells out of the chip, a main distribution chamber and eight microchannels connected to the main chamber to guide the growth of tip growing plant cells. The test cells used here were pollen grains which produce cylindrical protrusions called pollen tubes. The goal was to adjust the design of the microfluidic network with the aim to enhance the uniformly distributed positioning of pollen grains at the entrances of the microchannels and to provide identical fluid flow conditions for growing pollen tubes along each microchannel. Computational fluid analysis and experimental testing were carried out to estimate the trapping efficiencies of the different designs. PMID:24013680

Sanati Nezhad, Amir; Ghanbari, Mahmood; Agudelo, Carlos G; Naghavi, Mahsa; Packirisamy, Muthukumaran; Bhat, Rama B; Geitmann, Anja

2014-02-01

216

Optimization of plant mineral nutrition under growth-limiting conditions in a lunar greenhouse  

NASA Astrophysics Data System (ADS)

It may be assumed that the first plants in a lunar base will play a main role in forming a protosoil of acceptable fertility needed for purposively growing second generation plants like wheat, rice, tulips, etc. The residues of the first-generation plants could be composted and transformed by microorganisms into a soil-like substrate within a loop of regenerative life support system. The lunar regolith may be used as a substrate for plant growth at the very beginning of a mission to reduce its cost. The use of microbial communities for priming plants will allow one to facilitate adaption to stressful conditions and to support the plant development under growth limiting conditions. Well-defined plant-associated bacteria were used for growing three cultivars to colonize French marigold (Tagetes patula L.) in anorthosite, a substrate of low bioavailability, analogous to a lunar rock. The consortium was composed of plant growth promoting rhizobacteria and the bacterium Paenibacillus sp. IMBG156 which stimulated seed germination, better plant development, and finally, the flowering of inoculated tagetes. In contrast, control plants grew poorly in the anorthosite and practically did not survive until flowering. Analysis of bacterial community composition showed that all species colonized plant roots, however, the rate of colonization depended on the allelopatic characteristics of marigold varieties. Bacteria of consortium were able to liberate some elements (Ca, Fe, Mn, Si, Ni, Cu, Zn) from substrate anorthosite. Plant colonization by mixed culture of bacterial strains resulted in the increase of accumulation of K, Mg, Mn by the plant and in the lowering of the level of toxic metal accumulation. It was assumed that a rationally assembled consortium of bacterial strains promoted germination of marygold seeds and supported the plant development under growth limiting conditions by means of bioleaching plant essential nutritional elements and by protecting the plant against hyperaccumulation of some toxic metals.

Zaets, I.; Voznyuk, T.; Kovalchuk, M.; Rogutskyy, I.; Lukashov, D.; Mytrokhyn, O.; Mashkovska, S.; Foing, B.; Kozyrovska, N.

217

Physiological optimization underlies growth rate-independent chlorophyll-specific gross and net primary production.  

PubMed

Characterization of physiological variability in phytoplankton photosynthetic efficiencies is one of the greatest challenges in assessing ocean net primary production (NPP) from remote sensing of surface chlorophyll (Chl). Nutrient limitation strongly influences phytoplankton intracellular pigmentation, but its impact on Chl-specific NPP (NPP(*)) is debated. We monitored six indices of photosynthetic activity in steady-state Dunaliella tertiolecta cultures over a range of nitrate-limited growth rates (?), including photosynthetic efficiency of PSII (F(v)/F(m)), O(2)-based gross and net production, 20 min and 24 h carbon assimilation, and carbon- and ?-based NPP. Across all growth rates, O(2)-based Chl-specific gross primary production (GPP(*)(O(2))), NPP(*), and F(v)/F(m) were constant. GPP(*)(O(2)) was 3.3 times greater than NPP(*). In stark contrast, Chl-specific short-term C fixation showed clear linear dependence on ?, reflecting differential allocation of photosynthate between short-lived C products and longer-term storage products. Indeed, (14)C incorporation into carbohydrates was five times greater in cells growing at 1.2 day(-1) than 0.12 day(-1). These storage products are catabolized for ATP and reductant generation within the period of a cell cycle. The relationship between Chl-specific gross and net O(2) production, short-term (14)C-uptake, NPP(*), and growth rate reflects cellular-level regulation of fundamental metabolic pathways in response to nutrient limitation. We conclude that growth rate-dependent photosynthate metabolism bridges the gap between gross and net production and resolves a controversial question regarding nutrient limitation effects on primary production measures. PMID:20066494

Halsey, Kimberly H; Milligan, Allen J; Behrenfeld, Michael J

2010-02-01

218

Optimal Control of Film Growth in Lithium-Ion Battery Packs via Relay Switches  

Microsoft Academic Search

Recent advances in lithium-ion battery modeling suggest unequal but controlled and carefully timed charging of individual cells by reduce degradation. This paper compares anode-side film formation for a standard equalization scheme versus unequal charging through switches that are controlled by deterministic dynamic programming (DDP) and DDP-inspired heuristic algorithms. A static map for film growth rate is derived from a first-principles

Scott J. Moura; Joel C. Forman; Saeid Bashash; Jeffrey L. Stein; Hosam K. Fathy

2011-01-01

219

Growth optimization and optical properties of AlGaNAs alloys  

SciTech Connect

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.

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

220

Inhibition of growth of nonproteolytic Clostridium botulinum type B in sous vide cooked meat products is achieved by using thermal processing but not nisin.  

PubMed

The safety of refrigerated processed foods of extended durability (REPFEDs) with respect to nonproteolytic Clostridium botulinum is under continuous evaluation. In the present study, mild (P7.0(85.0) values 0 to 2 min [P, pasteurization value; z-value 7.0 degrees C; reference temperature 85.0 degrees C]) and increased (P7.0(85.0) values 67 to 515 min) heat treatments were evaluated in relation to survival of nonproteolytic C. botulinum type B spores in sous vide processed ground beef and pork cubes. The use of two concentrations of nisin in inhibition of growth and toxin production by nonproteolytic C. botulinum in the same products was also evaluated. A total of 96 samples were heat processed and analyzed for C. botulinum by BoNT/B gene-specific polmerase chain reaction and for botulinum toxin by a mouse bioassay after storage of 14 to 28 days at 4 and 8 degrees C. Predictably, after mild processing all samples of both products showed botulinal growth, and one ground beef sample became toxic at 8 degrees C. The increased heat processing, equivalent to 67 min at 85 degrees C. resulted in growth but not toxin production of C. botulinum in one ground beef sample in 21 days at 8 degrees C: in the pork cube samples no growth was detected. The increased heating of both products resulted in higher sensory quality than the milder heat treatment. Nisin did not inhibit the growth of nonproteolytic C. botulinum in either product; growth was detected in both products at 4 and 8 degrees C, and ground beef became toxic with all nisin levels within 21 to 28 days at 8 degrees C. Aerobic and lactic acid bacterial counts were reduced by the addition of nisin at 4 degrees C. The study demonstrates that the mild processing temperatures commonly employed in sous vide technology do not eliminate nonproteolytic C. botulinum type B spores. The intensity of each heat treatment needs to be carefully evaluated individually for each product to ensure product safety in relation to nonproteolytic C. botulinum. PMID:11403135

Lindström, M; Mokkila, M; Skyttä, E; Hyytiä-Trees, E; Lähteenmäki, L; Hielm, S; Ahvenainen, R; Korkeala, H

2001-06-01

221

Effect of Preform Compaction Pressure on the Final Microstructures and Superconducting Properties of YBa2Cu3O7- ? Superconductors Fabricated by Directionally Solidified Preform Optimized Infiltration Growth Process  

NASA Astrophysics Data System (ADS)

Bulk YBa2Cu3O7- ? (YBCO, Y-123) superconductors with reasonable critical current densities J c are successfully fabricated in relatively short-time durations employing Directionally Solidified Preform Optimized Infiltration Growth Process (DS-POIGP). The effect of preform compaction pressure, applied to Y2BaCuO5 (Y-211) preform prior to the infiltration of liquid phases, on the end microstructures and current densities is investigated. It is found that a preform compaction pressure of 460 MPa resulted in samples with superior microstructures and superconducting properties. YBCO sample fabricated by DS-POIGP under optimized conditions revealed presence of fine-sized Y-211 particles distributed uniformly in the matrix of Y-123 causing large interfacial defect density (Y-211/Y-123). Extensive twinning on a nano-scale with twins in the size range of 40-100 nm is observed in the optimized sample. These microstructural parameters enabled a considerable improvement in the field dependence of J c . Irreversibility fields greater than 5.5 Tesla even at 77 K are achieved in the optimized sample fabricated by DS-POIGP.

Devendra Kumar, N.; Missak Swarup Raju, P.; Pavan Kumar Naik, S.; Rajasekharan, T.; Seshubai, V.

2014-02-01

222

Computational Model Identifies Optimal Combinations of Targeted Therapeutics | Physical Sciences in Oncology  

Cancer.gov

As cancer researchers continue to develop powerful targeted therapeutics, it is becoming clear that these newer agents will need to be used in combination with one another to achieve optimal, long-lasting effects on tumor growth.

223

Optimization of Potent DFG-in Inhibitors of Platelet Derived Growth Factor Receptor? (PDGF-R?) Guided by Water Thermodynamics.  

PubMed

In this study we report on the hit optimization of substituted 3,5-diaryl-pyrazin-2(1H)-ones toward potent and effective platelet-derived growth factor receptor (PDGF-R) ?-inhibitors. Originally, the 3,5-diaryl-pyrazin-2-one core was derived from the marine sponge alkaloid family of hamacanthins. In our first series compound 2 was discovered as a promising hit showing strong activity against PDGF-R? in the kinase assay (IC50 = 0.5 ?M). Furthermore, 2 was shown to be selective for PDGF-R? in a panel of 24 therapeutically relevant protein kinases. Molecular modeling studies on a PDGF-R? homology model using prediction of water thermodynamics suggested an optimization strategy for the 3,5-diaryl-pyrazin-2-ones as DFG-in binders by using a phenolic OH function to replace a structural water molecule in the ATP binding site. Indeed, we identified compound 38 as a highly potent inhibitor with an IC50 value of 0.02 ?M in a PDGF-R? enzymatic assay also showing activity against PDGF-R dependent cancer cells. PMID:25007344

Horbert, Rebecca; Pinchuk, Boris; Johannes, Eugen; Schlosser, Joachim; Schmidt, Dorian; Cappel, Daniel; Totzke, Frank; Schächtele, Christoph; Peifer, Christian

2015-01-01

224

The content of African diets is adequate to achieve optimal efficacy with fixed-dose artemether-lumefantrine: a review of the evidence.  

PubMed

A fixed-dose combination of artemether-lumefantrine (AL, Coartem(R)) has shown high efficacy, good tolerability and cost-effectiveness in adults and children with uncomplicated malaria caused by Plasmodium falciparum. Lumefantrine bioavailability is enhanced by food, particularly fat.As the fat content of sub-Saharan African meals is approximately a third that of Western countries, it raises the question of whether fat consumption by African patients is sufficient for good efficacy. Data from healthy volunteers have indicated that drinking 36 mL soya milk (containing only 1.2 g of fat) results in 90% of the lumefantrine absorption obtained with 500 mL milk (16 g fat). African diets are typically based on a carbohydrate staple (starchy root vegetables, fruit [plantain] or cereals) supplemented by soups, relishes and sauces derived from vegetables, pulses, nuts or fish. The most important sources of dietary fat in African countries are oil crops (e.g. peanuts, soya beans) and cooking oils as red palm, peanut, coconut and sesame oils. Total fat intake in the majority of subSaharan countries is estimated to be in the range 30-60 g/person/day across the whole population (average 43 g/person/day). Breast-feeding of infants up to two years of age is standard, with one study estimating a fat intake of 15-30 g fat/day from breast milk up to the age of 18 months. Weaning foods typically contain low levels of fat, and the transition from breast milk to complete weaning is associated with a marked reduction in dietary fat. Nevertheless, fat intake >10 g/day has been reported in young children post-weaning. A randomized trial in Uganda reported no difference in the efficacy of AL between patients receiving supervised meals with a fixed fat content (~23 g fat) or taking AL unsupervised, suggesting that fat intake at home was sufficient for optimal efficacy. Moreover, randomized trials in African children aged 5-59 months have shown similar high cure rates to those observed in older populations, indicating that food consumption is adequate post-weaning. In conclusion, it appears that only a very small amount of dietary fat is necessary to ensure optimal efficacy with AL and that the fat content of standard meals or breast milk in sub-Saharan Africa is adequate. PMID:19032767

Premji, Zulfiqarali G; Abdulla, Salim; Ogutu, Bernhards; Ndong, Alice; Falade, Catherine O; Sagara, Issaka; Mulure, Nathan; Nwaiwu, Obiyo; Kokwaro, Gilbert

2008-01-01

225

Achievement of optimal average relative dose intensity and correlation with survival in diffuse large B-cell lymphoma patients treated with CHOP.  

PubMed

The treatment of diffuse large B-cell lymphoma with chemotherapy was retrospectively evaluated in 348 patients who had received at least three cycles of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone)-like, ACVBP (doxorubicin, cyclophosphamide, vindesine, bleomycin, and prednisone)-like or CHVmP-BV (cyclophosphamide, hydroxorubicin, Vm-26, prednisone, vincristine and bleomycin) treatment in Belgium between 1995 and 2000. In our sample, the proportion who received each of the three regimens was 78.4, 16.4, and 5.2%, respectively. Of those prescribed CHOP-like regimens, 15% received <80% average relative dose intensity (ARDI). In 210 patients treated with CHOP-21 (77% of the CHOP-like group), median survival was 7.08 years in those who received >90% of the ARDI, significantly longer than in those who received < or = 90% of the ARDI (p = 0.002). Dose reductions and/or delays, mainly due to hematological toxicities, resulted in a reduction in treatment intensity. These data indicate that patient outcome is improved when the intensity of chemotherapy treatment is optimal. PMID:17952688

Bosly, A; Bron, D; Van Hoof, A; De Bock, R; Berneman, Z; Ferrant, A; Kaufman, L; Dauwe, M; Verhoef, G

2008-04-01

226

Effect of optimal daily fertigation on migration of water and salt in soil, root growth and fruit yield of cucumber (Cucumis sativus L.) in solar-greenhouse.  

PubMed

Inappropriate and excessive irrigation and fertilization have led to the predominant decline of crop yields, and water and fertilizer use efficiency in intensive vegetable production systems in China. For many vegetables, fertigation can be applied daily according to the actual water and nutrient requirement of crops. A greenhouse study was therefore conducted to investigate the effect of daily fertigation on migration of water and salt in soil, and root growth and fruit yield of cucumber. The treatments included conventional interval fertigation, optimal interval fertigation and optimal daily fertigation. Generally, although soil under the treatment optimal interval fertigation received much lower fertilizers than soil under conventional interval fertigation, the treatment optimal interval fertigation did not statistically decrease the economic yield and fruit nutrition quality of cucumber when compare to conventional interval fertigation. In addition, the treatment optimal interval fertigation effectively avoided inorganic nitrogen accumulation in soil and significantly (P<0.05) increased the partial factor productivity of applied nitrogen by 88% and 209% in the early-spring and autumn-winter seasons, respectively, when compared to conventional interval fertigation. Although soils under the treatments optimal interval fertigation and optimal daily fertigation received the same amount of fertilizers, the treatment optimal daily fertigation maintained the relatively stable water, electrical conductivity and mineral nitrogen levels in surface soils, promoted fine root (<1.5 mm diameter) growth of cucumber, and eventually increased cucumber economic yield by 6.2% and 8.3% and partial factor productivity of applied nitrogen by 55% and 75% in the early-spring and autumn-winter seasons, respectively, when compared to the treatment optimal interval fertigation. These results suggested that optimal daily fertigation is a beneficial practice for improving crop yield and the water and fertilizers use efficiency in solar greenhouse. PMID:24475204

Liang, Xinshu; Gao, Yinan; Zhang, Xiaoying; Tian, Yongqiang; Zhang, Zhenxian; Gao, Lihong

2014-01-01

227

Effect of Optimal Daily Fertigation on Migration of Water and Salt in Soil, Root Growth and Fruit Yield of Cucumber (Cucumis sativus L.) in Solar-Greenhouse  

PubMed Central

Inappropriate and excessive irrigation and fertilization have led to the predominant decline of crop yields, and water and fertilizer use efficiency in intensive vegetable production systems in China. For many vegetables, fertigation can be applied daily according to the actual water and nutrient requirement of crops. A greenhouse study was therefore conducted to investigate the effect of daily fertigation on migration of water and salt in soil, and root growth and fruit yield of cucumber. The treatments included conventional interval fertigation, optimal interval fertigation and optimal daily fertigation. Generally, although soil under the treatment optimal interval fertigation received much lower fertilizers than soil under conventional interval fertigation, the treatment optimal interval fertigation did not statistically decrease the economic yield and fruit nutrition quality of cucumber when compare to conventional interval fertigation. In addition, the treatment optimal interval fertigation effectively avoided inorganic nitrogen accumulation in soil and significantly (P<0.05) increased the partial factor productivity of applied nitrogen by 88% and 209% in the early-spring and autumn-winter seasons, respectively, when compared to conventional interval fertigation. Although soils under the treatments optimal interval fertigation and optimal daily fertigation received the same amount of fertilizers, the treatment optimal daily fertigation maintained the relatively stable water, electrical conductivity and mineral nitrogen levels in surface soils, promoted fine root (<1.5 mm diameter) growth of cucumber, and eventually increased cucumber economic yield by 6.2% and 8.3% and partial factor productivity of applied nitrogen by 55% and 75% in the early-spring and autumn-winter seasons, respectively, when compared to the treatment optimal interval fertigation. These results suggested that optimal daily fertigation is a beneficial practice for improving crop yield and the water and fertilizers use efficiency in solar greenhouse. PMID:24475204

Liang, Xinshu; Gao, Yinan; Zhang, Xiaoying; Tian, Yongqiang; Zhang, Zhenxian; Gao, Lihong

2014-01-01

228

In vitro and in vivo evaluation of a novel collagen/cellulose nanocrystals scaffold for achieving the sustained release of basic fibroblast growth factor.  

PubMed

Tissue-engineered dermis is thought to be the best treatment for skin defects; however, slow vascularization of these biomaterial scaffolds limits their clinical application. Exogenous administration of angiogenic growth factors is highly desirable for tissue regeneration. In this study, biodegradable gelatin microspheres (GMs) containing basic fibroblast growth factor (bFGF) were fabricated and incorporated into a porous collagen/cellulose nanocrystals (CNCs) scaffold, as a platform for long-term release and consequent angiogenic boosting. The physicochemical properties of these scaffolds were examined and the in vitro release pattern of bFGF from scaffolds was measured by ELISA. Collagen/CNCs scaffolds with and without bFGF-GMs were incubated with human umbilical vein endothelial cells for 1 week, results showed that the scaffolds with bFGF-GMs significantly augmented cell proliferation. Then, four different groups of scaffolds were implanted subcutaneously into Sprague-Dawley rats to study angiogenesis in vivo via macroscopic observation, and hematoxylin and eosin and immunohistochemical staining. The results suggested that the collagen/CNCs/bFGF-GMs scaffolds had a significantly higher number of newly formed and mature blood vessels, and the fastest degradation rate. This study demonstrated that collagen/CNCs/bFGF-GMs scaffolds have great potential in skin tissue engineering. PMID:25114196

Li, Weichang; Lan, Yong; Guo, Rui; Zhang, Yi; Xue, Wei; Zhang, Yuanming

2015-01-01

229

Sharing Leadership Responsibilities Results in Achievement Gains  

ERIC Educational Resources Information Center

Collective, not individual, leadership in schools has a greater impact on student achievement; when principals and teachers share leadership responsibilities, student achievement is higher; and schools having high student achievement also display a vision for student achievement and teacher growth. Those are just a few of the insights into school…

Armistead, Lew

2010-01-01

230

Optimization of treatment parameters for the use of FLYASH amended composts for plant growth  

SciTech Connect

In continuation of the authors efforts to utilize coal fly ash as an amendment to organic manure for vegetation, four parameters such as the nature of the manure, plant-type, ash to manure and soil to amended compost ratios were investigated. a high grade organic manure, Gotta Grow, and a low grade manure, compost-manure, compost-toast, (Bricko Farm products) along with a home-made composed were used to make fly ash-amended composts. Four plants, collard green, mustard green, corn and sorghum were selected for study under greenhouse conditions. Keeping other variables constant, the fly ash to manure ratio was changed from 0 to 60% FA, and compost to soil ratio from 0 to 25%. The plants were grown for approximately 8 weeks and harvested. The plant yield was measured both before and after drying. It was found that out of four plants, yield from corn is the highest when fly ash-amended compost-toast (20% FA) was used at a compost to soil ratio of 1:3. The plant samples are being analyzed for major and minor elements including boron which is detrimental to the growth of plants.

Bacon, B.B.; Menon, M.P.; Ghuman, G.S.; James, J.; Adriano, D.C.; Chandra, K. (Savannah State College, GA (USA))

1990-01-01

231

11 Goals and achievements Goals and achievements  

E-print Network

11 Goals and achievements Goals and achievements Meteorological research at KNMI primarily aims and Schiphol airport. #12;12 Goals and achievements · Improving the efficiency of operational systems In order achievements in 2001 and 2002 for each of these areas are described. Observations One of the main goals has

Haak, Hein

232

Dyar's Rule and the Investment Principle: optimal moulting strategies if feeding rate is size-dependent and growth is discontinuous  

PubMed Central

We consider animals whose feeding rate depends on the size of structures that grow only by moulting (e.g. spiders' legs). Our Investment Principle predicts optimum size increases at each moult; under simplifying assumptions these are a function of the scaling of feeding rate with size, the efficiency of moulting and the optimum size increase at the preceding moult. We show how to test this quantitatively, and make the qualitative prediction that size increases and instar durations change monotonically through development. Thus, this version of the model does not predict that proportional size increases necessarily remain constant, which is the pattern described by Dyar's Rule. A literature survey shows that in nature size increases tend to decline and instar durations to increase, but exceptions to monotonicity occur frequently: we consider how relaxing certain assumptions of the model could explain this. Having specified various functions relating fitness to adult size and time of emergence, we calculate (using dynamic programming) the effect of manipulating food availability, time of hatching and size of the initial (or some intermediate) instar. The associated norms of reaction depend on the fitness function and differ from those when growth follows Dyar's Rule or is continuous. We go on to consider optimization of the number of instars. The Investment Principle then predicts upper and lower limits to observed size increases and explains why increases usually change little or decline through development. This is thus a new adaptive explanation for Dyar's Rule and for the most common deviation from the Rule.

Hutchinson, J. M. C.; McNamara, J. M.; Houston, A. I.; Vollrath, F.

1997-01-01

233

The Activity of Nodules of the Supernodulating Mutant Mtsunn Is not Limited by Photosynthesis under Optimal Growth Conditions  

PubMed Central

Legumes match the nodule number to the N demand of the plant. When a mutation in the regulatory mechanism deprives the plant of that ability, an excessive number of nodules are formed. These mutants show low productivity in the fields, mainly due to the high carbon burden caused through the necessity to supply numerous nodules. The objective of this study was to clarify whether through optimal conditions for growth and CO2 assimilation a higher nodule activity of a supernodulating mutant of Medicago truncatula (M. truncatula) can be induced. Several experimental approaches reveal that under the conditions of our experiments, the nitrogen fixation of the supernodulating mutant, designated as sunn (super numeric nodules), was not limited by photosynthesis. Higher specific nitrogen fixation activity could not be induced through short- or long-term increases in CO2 assimilation around shoots. Furthermore, a whole plant P depletion induced a decline in nitrogen fixation, however this decline did not occur significantly earlier in sunn plants, nor was it more intense compared to the wild-type. However, a distinctly different pattern of nitrogen fixation during the day/night cycles of the experiment indicates that the control of N2 fixing activity of the large number of nodules is an additional problem for the productivity of supernodulating mutants. PMID:24727372

Cabeza, Ricardo A.; Lingner, Annika; Liese, Rebecca; Sulieman, Saad; Senbayram, Mehmet; Tränkner, Merle; Dittert, Klaus; Schulze, Joachim

2014-01-01

234

Self-Beliefs and Student Goal Achievement  

ERIC Educational Resources Information Center

Two preliminary studies are presented investigating the self-beliefs that may affect goal achievement in a student population. In Study 1, goal achievement on an abstract task, where goals are externally set by others, is considered in relation to students' levels of optimism. In Study 2, goal achievement on academic performance, where goals are…

Wesson, Caroline J.; Derrer-Rendall, Nicola M.

2011-01-01

235

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

Microsoft Academic Search

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

Hendrik Poorter; Carlo Remkes

1990-01-01

236

Preform optimization in infiltration growth process: An efficient method to improve the superconducting properties of YBa2Cu3O7-?  

NASA Astrophysics Data System (ADS)

The effect of compaction pressure applied to the Y2BaCuO5 (Y-211) preform during its fabrication, on the final microstructures and current densities (Jc) is investigated. The necessity for optimizing the sintering conditions in order to provide mechanical stability to the preform prior to the infiltration of liquid phases is demonstrated. The sample fabricated under optimized conditions showed Jc values better than 103 A cm-2 up to applied magnetic fields of 6.5 Tesla at 77 K. The microstructural factors influencing the field dependence of Jc ‘Jc(H)’ at low and high fields are investigated. Extensive nano-twinning with large number of crossing twins observed in the optimized sample and the associated high defect densities are correlated to be the source of flux pinning to high fields. The fact that YBa2Cu3O7-? (YBCO, Y-123) superconductor obtained employing the present Preform Optimized Infiltration and Growth Process (POIGP) yields a homogenous and dense distribution of fine Y-211 particles, that creates suitable twin/defect densities to provide flux pinning at high fields, is of technical importance.

Devendra Kumar, N.; Rajasekharan, T.; Seshubai, V.

2013-12-01

237

Effect of Ag addition on the microstructures and superconducting properties of bulk YBCO fabricated by Directionally Solidified Preform Optimized Infiltration Growth Process  

NASA Astrophysics Data System (ADS)

A bulk YBa2Cu3O7-? (YBCO)/Ag superconducting composite with a homogenous distribution of fine and spherical particles of metallic Ag and Y2BaCuO5 (Y-211) has been fabricated by employing Directionally Solidified Preform Optimized Infiltration Growth Process (DS-POIGP). The effect of adding Ag into the liquid phase source (YBa2Cu3O7-?) placed above the Y-211 preform on the microstructures and current densities is investigated. The addition of Ag led to a significant refinement of Y-211 particle size and, hence, enabled the enhancement of current densities at low fields.

Devendra Kumar, N.; Missak Swarup Raju, P.; Pavan Kumar Naik, S.; Rajasekharan, T.; Seshubai, V.

2014-01-01

238

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

SciTech Connect

We present results on optimized growth temperatures and layer structure design of high mobility photoconductive Terahertz (THz) emitters based on molecular beam epitaxy grown In{sub 0.53}Ga{sub 0.47}As/In{sub 0.52}Al{sub 0.48}As 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{sup ?3}.

Dietz, Roman J. B.; Globisch, Björn; Stanze, Dennis; Roehle, Helmut; Göbel, Thorsten; Schell, Martin [Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institute, Einsteinufer 37, 10587 Berlin (Germany)] [Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institute, Einsteinufer 37, 10587 Berlin (Germany); Gerhard, Marina; Velauthapillai, Ajanthkrishna; Koch, Martin [Department of Physics, Philipps-Universität Marburg, Renthof 5, 35032 Marburg (Germany)] [Department of Physics, Philipps-Universität Marburg, Renthof 5, 35032 Marburg (Germany)

2013-08-05

239

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

NASA Astrophysics Data System (ADS)

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.

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

2013-08-01

240

NADH-regulated metabolic model for growth of Methylosinus trichosporium OB3b. Cometabolic degradation of trichloroethene and optimization of bioreactor system performance  

SciTech Connect

A metabolic model describing growth of Methylosinus trichosporium OB3b and cometabolic contaminant conversion is used to optimize trichloroethene (TCE) conversion in a bioreactor system. Different process configurations are compared: a growing culture and a nongrowing culture to which TCE is added at both constant and pulsed levels. The growth part of the model, presented in the preceding article, gives a detailed description of the NADH regeneration required for continued TCE conversion. It is based on the metabolic pathways, includes Michaelis--Menten type enzyme kinetics, and uses NADH as an integrating and controlling factor. Here the model is extended to include TCE transformation, incorporating the kinetics of contaminant conversion, the related NADH consumption, toxic effects, and competitive inhibition between TCE and methane. The model realistically describes the experimentally observed negative effects of the TCE conversion products, both on soluble methane monooxygenase through the explicit incorporation of the activity of this enzyme and on cell viability through the distinction between dividing and nondividing cells. In growth-based systems, the toxicity of the TCE conversion products causes rapid cell death, which leads to wash-out of suspended cultures at low TCE loads. Enzyme activity, which is less sensitive, is hardly affected by the toxicity of the TCE conversion products and ensures high conversions (>95%) up to the point of wash-out. Pulsed addition of TCE leads to a complete loss of viability. However, the remaining enzyme activity can still almost completely covert the subsequently added large TCE pulses. This emphasizes the inefficient use of enzyme activity in growth-based systems. A comparison of growth-based and similar non-growth-based systems reveals that the highest TCE conversions per amount of cells grown can be obtained in the latter. Using small amounts of methane, NADH limitation in the second step of this two-step system can be eliminated. This results in complete utilization of enzyme activity and thus in a very effective treatment system.

Sipkema, E.M.; Koning, W. de; Ganzeveld, K.J.; Janssen, D.B.; Beenackers, A.A.C.M.

2000-04-01

241

Trade-offs between drug toxicity and benefit in the multi-antibiotic resistance system underlie optimal growth of E. coli  

PubMed Central

Background Efflux is a widespread mechanism of reversible drug resistance in bacteria that can be triggered by environmental stressors, including many classes of drugs. While such chemicals when used alone are typically toxic to the cell, they can also induce the efflux of a broad range of agents and may therefore prove beneficial to cells in the presence of multiple stressors. The cellular response to a combination of such chemical stressors may be governed by a trade-off between the fitness costs due to drug toxicity and benefits mediated by inducible systems. Unfortunately, disentangling the cost-benefit interplay using measurements of bacterial growth in response to the competing effects of the drugs is not possible without the support of a theoretical framework. Results Here, we use the well-studied multiple antibiotic resistance (MAR) system in E. coli to experimentally characterize the trade-off between drug toxicity (“cost”) and drug-induced resistance (“benefit”) mediated by efflux pumps. Specifically, we show that the combined effects of a MAR-inducing drug and an antibiotic are governed by a superposition of cost and benefit functions that govern these trade-offs. We find that this superposition holds for all drug concentrations, and it therefore allows us to describe the full dose–response diagram for a drug pair using simpler cost and benefit functions. Moreover, this framework predicts the existence of optimal growth at a non-trivial concentration of inducer. We demonstrate that optimal growth does not coincide with maximum induction of the mar promoter, but instead results from the interplay between drug toxicity and mar induction. Finally, we derived and experimentally validated a general phase diagram highlighting the role of these opposing effects in shaping the interaction between two drugs. Conclusions Our analysis provides a quantitative description of the MAR system and highlights the trade-off between inducible resistance and the toxicity of the inducing agent in a multi-component environment. The results provide a predictive framework for the combined effects of drug toxicity and induction of the MAR system that are usually masked by bulk measurements of bacterial growth. The framework may also be useful for identifying optimal growth conditions in more general systems where combinations of environmental cues contribute to both transient resistance and toxicity. PMID:22631053

2012-01-01

242

Embryonic pig liver, pancreas, and lung as a source for transplantation: Optimal organogenesis without teratoma depends on distinct time windows  

Microsoft Academic Search

Pig embryonic tissues represent an attractive option for organ transplantation. However, the achievement of optimal organogenesis after transplantation, namely, maximal organ growth and function without teratoma development, represents a major challenge. In this study, we determined distinct gestational time windows for the growth of pig embryonic liver, pancreas, and lung precursors. Transplantation of embryonic-tissue precursors at various gestational ages [from

Smadar Eventov-Friedman; Helena Katchman; Elias Shezen; Anna Aronovich; Dalit Tchorsh; Benjamin Dekel; Enrique Freud; Yair Reisner

2005-01-01

243

Enhanced growth of influenza vaccine seed viruses in vero cells mediated by broadening the optimal pH range for virus membrane fusion.  

PubMed

Vaccination is one of the most effective preventive measures to combat influenza. Prospectively, cell culture-based influenza vaccines play an important role for robust vaccine production in both normal settings and urgent situations, such as during the 2009 pandemic. African green monkey Vero cells are recommended by the World Health Organization as a safe substrate for influenza vaccine production for human use. However, the growth of influenza vaccine seed viruses is occasionally suboptimal in Vero cells, which places limitations on their usefulness for enhanced vaccine production. Here, we present a strategy for the development of vaccine seed viruses with enhanced growth in Vero cells by changing an amino acid residue in the stem region of the HA2 subunit of the hemagglutinin (HA) molecule. This mutation optimized the pH for HA-mediated membrane fusion in Vero cells and enhanced virus growth 100 to 1,000 times in the cell line, providing a promising strategy for cell culture-based influenza vaccines. PMID:22090129

Murakami, Shin; Horimoto, Taisuke; Ito, Mutsumi; Takano, Ryo; Katsura, Hiroaki; Shimojima, Masayuki; Kawaoka, Yoshihiro

2012-02-01

244

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

E-print Network

1 Abstract -- The growth of non-conventional renewable energies involves a new challenge allocation method used in the electrical system in Chile. We present the method of distribution factors used in Chile and propose a bargaining method to reallocate the percentage of payment of transmission assets

Catholic University of Chile (Universidad Católica de Chile)

245

Osmoregulated Periplasmic Glucans (OPGs) of Salmonella enterica serovars Typhimurium are needed for optimal growth under nutrient limiting- hypoosmotic conditions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Osmoregulated periplasmic glucans (OPGs) are major periplasmic constituents of gram negative bacteria. Synthesis of OPGs is regulated by the osmolarity of the growth medium. The role of OPGs has been postulated in plant-symbiotic as well as pathogenic microorganisms. On the other hand, opg mutant...

246

Communicating to Diverse Audiences to Achieve Your Goals  

E-print Network

·1 Communicating to Diverse Audiences to Achieve Your Goals Charlie MacPherson Tetra Tech, Inc? Monitoring results Progress achieved Trends Legislative accomplishments Growth in the organization Kudos WHO

247

Optimizing reproductive phenology in a two-resource world: a dynamic allocation model of plant growth predicts later reproduction in phosphorus-limited plants  

PubMed Central

Background and Aims Timing of reproduction is a key life-history trait that is regulated by resource availability. Delayed reproduction in soils with low phosphorus availability is common among annuals, in contrast to the accelerated reproduction typical of other low-nutrient environments. It is hypothesized that this anomalous response arises from the high marginal value of additional allocation to root growth caused by the low mobility of phosphorus in soils. Methods To better understand the benefits and costs of such delayed reproduction, a two-resource dynamic allocation model of plant growth and reproduction is presented. The model incorporates growth, respiration, and carbon and phosphorus acquisition of both root and shoot tissue, and considers the reallocation of resources from senescent leaves. The model is parameterized with data from Arabidopsis and the optimal reproductive phenology is explored in a range of environments. Key Results The model predicts delayed reproduction in low-phosphorus environments. Reproductive timing in low-phosphorus environments is quite sensitive to phosphorus mobility, but is less sensitive to the temporal distribution of mortality risks. In low-phosphorus environments, the relative metabolic cost of roots was greater, and reproductive allocation reduced, compared with high-phosphorus conditions. The model suggests that delayed reproduction in response to low phosphorus availability may be reduced in plants adapted to environments where phosphorus mobility is greater. Conclusions Delayed reproduction in low-phosphorus soils can be a beneficial response allowing for increased acquisition and utilization of phosphorus. This finding has implications both for efforts to breed crops for low-phosphorus soils, and for efforts to understand how climate change may impact plant growth and productivity in low-phosphorus environments. PMID:21712299

Nord, Eric A.; Shea, Katriona; Lynch, Jonathan P.

2011-01-01

248

Optimal conditions for mycelial growth of Schizosaccharomyces japonicus cells in liquid medium: it enables the molecular investigation of dimorphism.  

PubMed

The non-pathogenic dimorphic fission yeast, Schizosaccharomyces japonicus, could be a suitable model organism for investigation of the genetic background of mycelial growth, as it has a haploid chromosome set and its genome is sequenced. Since earlier results have suggested that its morphological transition required solid substrates, but molecular biological experiments would require hyphae production in a liquid medium, we wanted to find circumstances which would enable hyphae production in liquid media. Several external conditions were investigated, but the strongest inducer was fetal bovine serum (FBS). Its positive effect could be hampered by heat and was dependent on pH, temperature and concentration of the serum. Other protein-containing compounds, such as peptone and bovine serum albumin or amino acids, proved to be ineffective or weak. Generally, the uninduced and induced mycelial growth of Sz. japonicus could be improved by lower external pH and higher temperature. PMID:25308606

Papp, László; Sipiczki, Matthias; Holb, Imre J; Miklós, Ida

2014-12-01

249

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

USGS Publications Warehouse

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.

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

250

Optimal water temperature and pH for development of eggs and growth of spawn of common carp (Cyprinus carpio)  

Microsoft Academic Search

The objective of the present study was to determine the influence of water temperatures (26, 28 and 30 C) and pH (5.5, 6.5, 7.5 and 8.5) variations on the hatchability of eggs and growth of spawn of common carp, Cyprinus carpio. The present results indicated that percentage of hatchability of eggs and incubation period decreased with increase in temperatures from

P. H. Sapkale; R. K. Singh

2011-01-01

251

Chlamydia pneumoniae harness host NLRP3 inflammasome-mediated caspase-1 activation for optimal intracellular growth in murine macrophages.  

PubMed

Chlamydia pneumoniae is an obligate intracellular pathogen that replicates within a vacuole and acquires host cell nutrients. We show that C. pneumoniae utilizes host innate immune signaling NLRP3/ASC/caspase-1 inflammasome for intracellular growth. Bone marrow-derived macrophages (BMMs) secreted mature interleukin-1? upon infection with C. pneumoniae depending on the NLRP3 inflammasome activation. Intracellular growth of C. pneumoniae was severely impaired in BMMs from Nlrp3(-/-), Asc(-/-), and Casp1(-/-) mice but not wild type or Nlrc4(-/-) mice. Furthermore defective NLRP3 inflammasome components led to accumulation of lipid droplets inside the infected BMMs, suggesting that uptake and/or utilization of lipids is disturbed in the absence of NLRP3 inflammasome activation. These results suggest C. pneumoniae has evolved to harness both host innate immune response and NLRP3 inflammasome activation, for the acquisition of essential nutrients necessary for intracellular growth. This unique property of C. pneumoniae may shed a new light on how C. pneumoniae increase the risk of atherosclerosis and metabolic syndrome. PMID:25193701

Itoh, Ryota; Murakami, Issaku; Chou, Bin; Ishii, Kazunari; Soejima, Toshinori; Suzuki, Toshihiko; Hiromatsu, Kenji

2014-09-26

252

Mycelium growth kinetics and optimal temperature conditions for the cultivation of edible mushroom species on lignocellulosic substrates.  

PubMed

The influence of environmental parameters on mycelial linear growth of Pleurotus ostreatus, P. eryngii, P. pulmonarius, Agrocybe aegerita, Lentinula edodes, Volvariella volvacea and Auricularia auricula-judae was determined in two different nutrient media in a wide range of temperature, forming the basis for the assessment of their temperature optima. V. volvacea grew faster at 35 degrees C, P. eryngii at 25 degrees C, P. ostreatus and P. pulmonarius at 30 degrees C, A. aegerita at 25 or 30 degrees C and A. auricula-judae at 20 or 25 degrees C depending on the nutrient medium used and L. edodes at 20 or 30 degrees C depending on the strain examined. The mycelium extension rates were evaluated on seven mushroom cultivation substrates: wheat straw, cotton gin-trash, peanut shells, poplar sawdust, oak sawdust, corn cobs and olive press-cake. The mycelium extension rates (linear growth and colonization rates) were determined by the 'race-tube' technique, and were found to be the highest on cotton gin-trash, peanut shells and poplar sawdust for Pleurotus spp. and A. aegerita. Wheat straw, peanut shells and particularly cotton gin-trash supported fast growth of V. volvacea, whereas wheat straw was the most suitable substrate for L. edodes and A. auricula-judae. Supplemented oak sawdust and olive press-cake were poor substrates for most species examined, while almost all strains performed adequately on corn cobs. PMID:11702409

Zervakis, G; Philippoussis, A; Ioannidou, S; Diamantopoulou, P

2001-01-01

253

Achieving Public Schools  

ERIC Educational Resources Information Center

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…

Abowitz, Kathleen Knight

2011-01-01

254

Assessing Handwriting Achievement.  

ERIC Educational Resources Information Center

Notes that handwriting achievement can be assessed in degrees from being legible to being illegible. Suggests that a rubric, carefully developed and designed, may well be used to ascertain the quality of handwriting achievement. Gives a brief history of handwriting instruction. Presents 10 points for teachers to follow when teaching handwriting.…

Ediger, Marlow

2002-01-01

255

Profiling High Numeracy Achievement  

ERIC Educational Resources Information Center

Profiling high numeracy achievement is the South Australian Department of Education and Children's Services component of the Australian Government funded Strategic Numeracy Research and Development Initiative. This article presents the Profiling High Numeracy Achievement Project Team report on the South Australian Department of Education and…

Australian Primary Mathematics Classroom, 2004

2004-01-01

256

General Achievement Trends: Vermont  

ERIC Educational Resources Information Center

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…

Center on Education Policy, 2009

2009-01-01

257

Achievement Test Program.  

ERIC Educational Resources Information Center

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…

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

258

AMT1;1 transgenic rice plants with enhanced NH4 + permeability show superior growth and higher yield under optimal and suboptimal NH4 + conditions  

PubMed Central

The major source of nitrogen for rice (Oryza sativa L.) is ammonium (NH4 +). The NH4 + uptake of roots is mainly governed by membrane transporters, with OsAMT1;1 being a prominent member of the OsAMT1 gene family that is known to be involved in NH4 + transport in rice plants. However, little is known about its involvement in NH4 + uptake in rice roots and subsequent effects on NH4 + assimilation. This study shows that OsAMT1;1 is a constitutively expressed, nitrogen-responsive gene, and its protein product is localized in the plasma membrane. Its expression level is under the control of circadian rhythm. Transgenic rice lines (L-2 and L-3) overexpressing the OsAMT1;1 gene had the same root structure as the wild type (WT). However, they had 2-fold greater NH4 + permeability than the WT, whereas OsAMT1;1 gene expression was 20-fold higher than in the WT. Analogous to the expression, transgenic lines had a higher NH4 + content in the shoots and roots than the WT. Direct NH4 + fluxes in the xylem showed that the transgenic lines had significantly greater uptake rates than the WT. Higher NH4 + contents also promoted higher expression levels of genes in the nitrogen assimilation pathway, resulting in greater nitrogen assimilates, chlorophyll, starch, sugars, and grain yield in transgenic lines than in the WT under suboptimal and optimal nitrogen conditions. OsAMT1;1 also enhanced overall plant growth, especially under suboptimal NH4 + levels. These results suggest that OsAMT1;1 has the potential for improving nitrogen use efficiency, plant growth, and grain yield under both suboptimal and optimal nitrogen fertilizer conditions. PMID:24420570

Rothstein, Steven J.

2014-01-01

259

Using School-Level Student Achievement to Engage in Formative Evaluation: Comparative School-Level Rates of Oral Reading Fluency Growth Conditioned by Initial Skill for Second Grade Students  

ERIC Educational Resources Information Center

We present a method for data-based decision making at the school level using student achievement data. We demonstrate the potential of a national assessment database [i.e., the University of Oregon DIBELS Data System (DDS)] to provide comparative levels of school-level data on average student achievement gains. Through the DDS as a data source,…

Cummings, Kelli D.; Stoolmiller, Michael L.; Baker, Scott K.; Fien, Hank; Kame'enui, Edward J.

2015-01-01

260

[Achievement of therapeutic objectives].  

PubMed

Therapeutic objectives for patients with atherogenic dyslipidemia are achieved by improving patient compliance and adherence. Clinical practice guidelines address the importance of treatment compliance for achieving objectives. The combination of a fixed dose of pravastatin and fenofibrate increases the adherence by simplifying the drug regimen and reducing the number of daily doses. The good tolerance, the cost of the combination and the possibility of adjusting the administration to the patient's lifestyle helps achieve the objectives for these patients with high cardiovascular risk. PMID:25043543

Mantilla, Teresa

2014-07-01

261

Achievement goals and emotions.  

PubMed

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

Puente-Díaz, Rogelio

2013-01-01

262

Manipulating Crystallographic Texture of Sn Coatings by Optimization of Electrodeposition Process Conditions to Suppress Growth of Whiskers  

NASA Astrophysics Data System (ADS)

The effects of two major electrodeposition process conditions, electrolyte bath temperature and current density, on the microstructure and crystallographic texture of pure tin coatings on brass and, ultimately, on the extent of whisker formation have been examined. The grain size of the deposited coatings increased with increasing electrolyte bath temperature and current density, which significantly affected the dominant texture: (211) or (420) was the dominant texture at low current densities whereas, depending on deposition temperature, (200) or (220) became the dominant texture at high current densities. After deposition, coatings were subjected to different environmental conditions, for example isothermal aging (room temperature, 50°C, or 150°C) for up to 90 days and thermal cycling between -25°C and 85°C for 100 cycles, and whisker growth was studied. The Sn coatings with low Miller index planes, for example (200) and (220), and with moderate aging temperature were more prone to whiskering than coating with high Miller index planes, for example (420), and high aging temperature. A processing route involving the optimum combination of current density and deposition temperature is proposed for suppressing whisker growth.

Jagtap, Piyush; Kumar, Praveen

2015-01-01

263

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

PubMed Central

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

2012-01-01

264

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

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%.

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

265

Genome-Wide Mutant Fitness Profiling Identifies Nutritional Requirements for Optimal Growth of Yersinia pestis in Deep Tissue  

PubMed Central

ABSTRACT Rapid growth in deep tissue is essential to the high virulence of Yersinia pestis, causative agent of plague. To better understand the mechanisms underlying this unusual ability, we used transposon mutagenesis and high-throughput sequencing (Tn-seq) to systematically probe the Y. pestis genome for elements contributing to fitness during infection. More than a million independent insertion mutants representing nearly 200,000 unique genotypes were generated in fully virulent Y. pestis. Each mutant in the library was assayed for its ability to proliferate in vitro on rich medium and in mice following intravenous injection. Virtually all genes previously established to contribute to virulence following intravenous infection showed significant fitness defects, with the exception of genes for yersiniabactin biosynthesis, which were masked by strong intercellular complementation effects. We also identified more than 30 genes with roles in nutrient acquisition and metabolism as experiencing strong selection during infection. Many of these genes had not previously been implicated in Y. pestis virulence. We further examined the fitness defects of strains carrying mutations in two such genes—encoding a branched-chain amino acid importer (brnQ) and a glucose importer (ptsG)—both in vivo and in a novel defined synthetic growth medium with nutrient concentrations matching those in serum. Our findings suggest that diverse nutrient limitations in deep tissue play a more important role in controlling bacterial infection than has heretofore been appreciated. Because much is known about Y. pestis pathogenesis, this study also serves as a test case that assesses the ability of Tn-seq to detect virulence genes. PMID:25139902

Palace, Samantha G.; Proulx, Megan K.; Lu, Shan; Baker, Richard E.

2014-01-01

266

Optimization of codon composition and regulatory elements for expression of human insulin like growth factor-1 in transgenic chloroplasts and evaluation of structural identity and function  

PubMed Central

Background Transgenic chloroplasts are potential bioreactors for recombinant protein production, especially for achievement of high levels of protein expression and proper folding. Production of therapeutic proteins in leaves provides transgene containment by elimination of reproductive structures. Therefore, in this study, human Insulin like Growth Factor-1 is expressed in transgenic chloroplasts for evaluation of structural identity and function. Results Expression of the synthetic Insulin like Growth Factor 1 gene (IGF-1s, 60% AT) was observed in transformed E. coli. However, no native IGF-1 gene (IGF-1n, 41% AT) product was detected in the western blots in E. coli. Site-specific integration of the transgenes into the tobacco chloroplast genome was confirmed after transformation using PCR. Southern blot analysis confirmed that the transgenic lines were homoplasmic. The transgenic plant lines had IGF-1s expression levels of 11.3% of total soluble protein (TSP). The IGF-1n plants contained 9.5% TSP as IGF-1n, suggesting that the chloroplast translation machinery is more flexible than E. coli in codon preference and usage. The expression of IGF-1 was increased up to 32% TSP under continuous illumination by the chloroplast light regulatory elements. IgG-Sepharose affinity column chromatographic separation of Z domain containing chloroplast derived IGF-1 protein, single and two dimensional electrophoresis methods and mass spectrometer analysis confirmed the identity of human IGF-1 in transgenic chloroplasts. Two spots analyzed from 2-D focusing/phoresis acrylamide gel showed the correct amino acid sequence of human IGF-1 and the S. aureus Z-tag. Cell proliferation assays in human HU-3 cells demonstrated the biological activity of chloroplast derived IGF-1 even in the presence of the S. aureus Z tag. Conclusion This study demonstrates that the human Insulin like Growth Factor-1 expressed in transgenic chloroplasts is identical to the native protein and is fully functional. The ability to use plant chloroplasts as bioreactors to generate proteins of great economic value that retain their biological activity is an exciting and achievable goal that appears to be within our grasp. PMID:19344517

Daniell, Henry; Ruiz, Gricel; Denes, Bela; Sandberg, Laurence; Langridge, William

2009-01-01

267

Posttraumatic growth in former Vietnam prisoners of war.  

PubMed

This study examined posttraumatic growth in 30 male veterans captured and held as prisoners of war during the Vietnam War. Participants were assessed with structured diagnostic interviews administered by trained clinicians as well as with the Posttraumatic Growth Inventory (PTGI) and other questionnaires measuring dispositional optimism, religious coping, social supports, and purpose in life. Mean age (standard deviation-SD) of participants was 66.7 (6.0) years. Mean total PTGI score (SD) was 66.3 (17.5), indicating a moderate degree of posttraumatic growth. The most strongly endorsed items corresponded to the Appreciation of Life and Personal Strength factors. The group as a whole was optimistic and reported moderate use of positive religious coping. Posttraumatic growth did not significantly differ in repatriates with and without psychopathology, but it was significantly positively correlated with dispositional optimism. In the final regression model, length of captivity and optimism were significant predictors of posttraumatic growth. Our findings confirm that it is possible to achieve long-lasting personal growth even in the face of prolonged extreme adversity. Prospective studies are needed to further evaluate whether pre-existing traits such as optimism can predict growth after trauma. PMID:19152285

Feder, Adriana; Southwick, Steven M; Goetz, Raymond R; Wang, Yanping; Alonso, Angelique; Smith, Bruce W; Buchholz, Katherine R; Waldeck, Tracy; Ameli, Rezvan; Moore, Jeffrey; Hain, Robert; Charney, Dennis S; Vythilingam, Meena

2008-01-01

268

Entropy production of a steady-growth cell with catalytic reactions  

NASA Astrophysics Data System (ADS)

Cells generally convert external nutrient resources to support metabolism and growth. Understanding the thermodynamic efficiency of this conversion is essential to determine the general characteristics of cellular growth. Using a simple protocell model with catalytic reaction dynamics to synthesize the necessary enzyme and membrane components from nutrients, the entropy production per unit-cell-volume growth is calculated analytically and numerically based on the rate equation for chemical kinetics and linear nonequilibrium thermodynamics. The minimal entropy production per unit-cell growth is found to be achieved at a nonzero nutrient uptake rate rather than at a quasistatic limit as in the standard Carnot engine. This difference appears because the equilibration mediated by the enzyme exists only within cells that grow through enzyme and membrane synthesis. Optimal nutrient uptake is also confirmed by protocell models with many chemical components synthesized through a catalytic reaction network. The possible relevance of the identified optimal uptake to optimal yield for cellular growth is also discussed.

Himeoka, Yusuke; Kaneko, Kunihiko

2014-10-01

269

Achieving yield gains in wheat.  

PubMed

Wheat provides 20% of calories and protein consumed by humans. Recent genetic gains are <1% per annum (p.a.), insufficient to meet future demand. The Wheat Yield Consortium brings expertise in photosynthesis, crop adaptation and genetics to a common breeding platform. Theory suggest radiation use efficiency (RUE) of wheat could be increased ~50%; strategies include modifying specificity, catalytic rate and regulation of Rubisco, up-regulating Calvin cycle enzymes, introducing chloroplast CO(2) concentrating mechanisms, optimizing light and N distribution of canopies while minimizing photoinhibition, and increasing spike photosynthesis. Maximum yield expression will also require dynamic optimization of source: sink so that dry matter partitioning to reproductive structures is not at the cost of the roots, stems and leaves needed to maintain physiological and structural integrity. Crop development should favour spike fertility to maximize harvest index so phenology must be tailored to different photoperiods, and sensitivity to unpredictable weather must be modulated to reduce conservative responses that reduce harvest index. Strategic crossing of complementary physiological traits will be augmented with wide crossing, while genome-wide selection and high throughput phenotyping and genotyping will increase efficiency of progeny screening. To ensure investment in breeding achieves agronomic impact, sustainable crop management must also be promoted through crop improvement networks. PMID:22860982

Reynolds, Matthew; Foulkes, John; Furbank, Robert; Griffiths, Simon; King, Julie; Murchie, Erik; Parry, Martin; Slafer, Gustavo

2012-10-01

270

Student Achievement, Personal Achievement Goal Orientations, and Perceptions of Classroom Goal Structures in a Standards-Based Reporting System  

ERIC Educational Resources Information Center

The purpose of this study was to analyze student achievement growth and motivational goal orientations in a standards-based reporting environment in a rural SC school district. More specifically, this study sought to determine if student achievement growth is related to the number of years students received standards-based reports in middle…

Ballard, Amy Copeland

2010-01-01

271

Achieving Zero Net Migration.  

ERIC Educational Resources Information Center

Unemployment in the United States can only be made worse by continued high levels of legal immigration. Especially serious is the threat from Latin America. We must help developing countries halt their population growth and impose a ceiling of 100,000 a year for total immigration to the United States. (RM)

Mann, Donald

1984-01-01

272

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

PubMed

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?

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

2014-03-01

273

Achieving Peace through Education.  

ERIC Educational Resources Information Center

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…

Clarken, Rodney H.

274

The Achievement Club  

ERIC Educational Resources Information Center

When Gabrielle Carpenter became a guidance counselor in Northern Virginia nine years ago, she focused on the academic achievement gap and furiously tried to close it. At first, she was compelled by tremendous professional interest. However, after seeing her son lose his zeal for school, Carpenter joined forces with other parents to form an…

Rogers, Ibram

2009-01-01

275

Explorations in achievement motivation  

NASA Technical Reports Server (NTRS)

Recent research on the nature of achievement motivation is reviewed. A three-factor model of intrinsic motives is presented and related to various criteria of performance, job satisfaction and leisure activities. The relationships between intrinsic and extrinsic motives are discussed. Needed areas for future research are described.

Helmreich, Robert L.

1982-01-01

276

Iowa Women of Achievement.  

ERIC Educational Resources Information Center

This issue of the Goldfinch highlights some of Iowa's 20th century women of achievement. These women have devoted their lives to working for human rights, education, equality, and individual rights. They come from the worlds of politics, art, music, education, sports, business, entertainment, and social work. They represent Native Americans,…

Ohrn, Deborah Gore, Ed.

1993-01-01

277

Culture and achievement motivation  

Microsoft Academic Search

Analyzes 3 strategies for determining when and under what conditions persistence, choice, and variation in performance occur in the study of motivation. The 1st strategy relates to the role of personality in motivation. The 2nd strategy suggests that situational variables play a major role in achievement motivation, and the 3rd strategy specifically identifies both personality and situation as simultaneously critical

Martin L. Maehr

1974-01-01

278

Learning to Achieve Goals  

Microsoft Academic Search

Temporal difference methods solve the temporalcredit assignment problem for reinforcementlearning. An important subproblem ofgeneral reinforcement learning is learning toachieve dynamic goals. Although existing temporaldifference methods, such as Q learning,can be applied to this problem, they do nottake advantage of its special structure. This paperpresents the DG-learning algorithm, whichlearns efficiently to achieve dynamically changinggoals and exhibits good knowledge transfer...

Leslie Pack Kaelbling

1993-01-01

279

Assessing Handwriting Achievement.  

ERIC Educational Resources Information Center

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.…

Ediger, Marlow

280

NCLB: Achievement Robin Hood?  

ERIC Educational Resources Information Center

In his "Wall Street Journal" op-ed on the 25th of anniversary of "A Nation At Risk", former assistant secretary of education Chester E. Finn Jr. applauded the report for turning U.S. education away from equality and toward achievement. It was not surprising, then, that in mid-2008, Finn arranged a conference to examine the potential "Robin Hood…

Bracey, Gerald W.

2008-01-01

281

Achieving Sustainability Cindy Carlsson  

E-print Network

Achieving Sustainability Cindy Carlsson Mn/DOT Office of Policy Analysis, Research and Innovation April 21, 2011 #12;Sustainability Is Not New Mn/DOT has long been a leader in CSS and environmental excellence. . . . . . so we're well along on the path to sustainability! #12;Today Sustainability is More

Minnesota, University of

282

Achieving Sustainability Cindy Carlsson  

E-print Network

Achieving Sustainability at MnDOT Cindy Carlsson MnDOT Office of Policy Analysis, Research and Innovation 22nd Annual Transportation Research Conference May 24, 2011 #12;Sustainable practices respect Sustainability #12;Environmental Sustainability Sustainable practices · Are compatible with and may enhance

Minnesota, University of

283

Schooling and Social Achievement.  

ERIC Educational Resources Information Center

Until the 1960s schooling in Korea was looked upon quite favorably as a means of achieving equal social and economic opportunities. In the 1970s, however, many began to raise the question of whether the expansion of educational opportunities really did reduce social inequalities. This report discusses research that analyzes available evidence…

Kim, Byong-sung; And Others

284

Achieving All Our Ambitions  

ERIC Educational Resources Information Center

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…

Hartley, Tricia

2009-01-01

285

The Fifth Achievement  

ERIC Educational Resources Information Center

The authors foresee a fifth achievement by which men will ultimately be able to work out their differences. Here presented is the Conflict Grid for use in evaluating good or bad ways of ending disputes as a vehicle for creative problem solving in the future. (Author)

Blake, Robert R.; Mouton, Jane Srygley

1970-01-01

286

Leadership Issues: Raising Achievement.  

ERIC Educational Resources Information Center

This document contains five papers examining the meaning and operation of leadership as a variable affecting student achievement in further education colleges in the United Kingdom. "Introduction" (Chris Horsfall) discusses school effectiveness studies' findings regarding the relationship between leadership and effective schools, distinguishes…

Horsfall, Chris, Ed.

287

Intelligence and Educational Achievement  

ERIC Educational Resources Information Center

This 5-year prospective longitudinal study of 70,000+ English children examined the association between psychometric intelligence at age 11 years and educational achievement in national examinations in 25 academic subjects at age 16. The correlation between a latent intelligence trait (Spearman's "g"from CAT2E) and a latent trait of educational…

Deary, Ian J.; Strand, Steve; Smith, Pauline; Fernandes, Cres

2007-01-01

288

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

PubMed Central

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

Pérez, Natalie Marie; Ramakrishnan, Girija

2014-01-01

289

Sustaining School Achievement in California's Elementary Schools after State Monitoring  

ERIC Educational Resources Information Center

This study examined the Academic Performance Index (API) and Adequate Yearly Progress (AYP) achievement trends between 2004 and 2006 of 58 California public elementary schools after exiting state monitoring and investigated practices for sustaining consistent achievement growth. Statistical methods were used to analyze statewide achievement trends…

McCabe, Molly

2010-01-01

290

Junior Achievement Student Center  

NSDL National Science Digital Library

Junior Achievement is an organization that is more than 90 years old and "dedicated to educating students about workforce readiness, entrepreneurship and financial literacy through experiential, hands-on programs." The Junior Achievement Student Center website focuses on "money management", "work readiness", and "business ownership". Visitors can play online "Games", such as "JA Titan", "JA Banks in Action", "JA Money Might", and JA Count on It". "JA Titan" promotes the visitor to CEO of a business, and tests the skills needed to defeat competitors; "JA Money Might" tests financial skills in an online simulation of real life situations. The "Learn" tab teaches visitors about "Money", "Work", "Business", and "The Economy". There is also an "Ethics" section in the "Learn" tab, and it includes 40 downloadable classroom activities, a case study, and an essay contest.

291

Cannabis and educational achievement  

Microsoft Academic Search

Aims To examine the relationship between cannabis use in adolescence\\/young adulthood and levels of educational attainment. Design Data were gathered over the course of a 25-year longitudinal study of a birth cohort of 1265 New Zealand children. Measurements Measures analysed included (a) frequency of cannabis use in adolescence and young adulthood (15-25 years); (b) levels of educational achievement to age

David M. Fergusson; L. John Horwood; Annette L. Beautrais

2003-01-01

292

Optimization of Reliability Allocation and Testing Schedule for Software Systems Michael R. Lyu  

E-print Network

, subject to some testing sched- ule and resource constraints. The system testing activity can be formulated as a combinatorial optimization prob- lem with known cost, reliability, effort, and other attributes of the system to the testing cost through various types of reliability growth curves. We achieve closed-form solutions

Newcastle upon Tyne, University of

293

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

E-print Network

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

Mountziaris, T. J.

294

Does achievement motivation mediate the semantic achievement priming effect?  

PubMed

The aim of our research was to understand the processes of the prime-to-behavior effects with semantic achievement primes. We extended existing models with a perspective from achievement motivation theory and additionally used achievement primes embedded in the running text of excerpts of school textbooks to simulate a more natural priming condition. Specifically, we proposed that achievement primes affect implicit achievement motivation and conducted pilot experiments and 3 main experiments to explore this proposition. We found no reliable positive effect of achievement primes on implicit achievement motivation. In light of these findings, we tested whether explicit (instead of implicit) achievement motivation is affected by achievement primes and found this to be the case. In the final experiment, we found support for the assumption that higher explicit achievement motivation implies that achievement priming affects the outcome expectations. The implications of the results are discussed, and we conclude that primes affect achievement behavior by heightening explicit achievement motivation and outcome expectancies. PMID:24820250

Engeser, Stefan; Baumann, Nicola

2014-10-01

295

Achievement Goals and Achievement Emotions: A Meta-analysis  

Microsoft Academic Search

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.\\u000a Achievement goals were meaningfully associated with different achievement emotions. The correlations of mastery and mastery\\u000a approach goals with positive achievement emotions and those between performance avoidance goals and negative achievement emotions\\u000a were large based on Cohen’s guidelines.

Chiungjung Huang

296

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)

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.

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

2014-05-01

297

Achievement Goals and the Hierarchical Model of Achievement Motivation  

Microsoft Academic Search

The achievement goal approach has attained prominence in the achievement motivation literature and has produced a valuable empirical yield. However, the precise nature of the achievement goal construct is in need of scrutiny, as is the issue of how achievement goals and their antecedents combine to produce competence-based self-regulation. In this article, we address these important conceptual issues in the

Andrew J. Elliot; Todd M. Thrash

2001-01-01

298

Prospective Optimization.  

PubMed

Human performance approaches that of an ideal observer and optimal actor in some perceptual and motor tasks. These optimal abilities depend on the capacity of the cerebral cortex to store an immense amount of information and to flexibly make rapid decisions. However, behavior only approaches these limits after a long period of learning while the cerebral cortex interacts with the basal ganglia, an ancient part of the vertebrate brain that is responsible for learning sequences of actions directed toward achieving goals. Progress has been made in understanding the algorithms used by the brain during reinforcement learning, which is an online approximation of dynamic programming. Humans also make plans that depend on past experience by simulating different scenarios, which is called prospective optimization. The same brain structures in the cortex and basal ganglia that are active online during optimal behavior are also active offline during prospective optimization. The emergence of general principles and algorithms for goal-directed behavior has consequences for the development of autonomous devices in engineering applications. PMID:25328167

Sejnowski, Terrence J; Poizner, Howard; Lynch, Gary; Gepshtein, Sergei; Greenspan, Ralph J

2014-05-01

299

Prospective Optimization  

PubMed Central

Human performance approaches that of an ideal observer and optimal actor in some perceptual and motor tasks. These optimal abilities depend on the capacity of the cerebral cortex to store an immense amount of information and to flexibly make rapid decisions. However, behavior only approaches these limits after a long period of learning while the cerebral cortex interacts with the basal ganglia, an ancient part of the vertebrate brain that is responsible for learning sequences of actions directed toward achieving goals. Progress has been made in understanding the algorithms used by the brain during reinforcement learning, which is an online approximation of dynamic programming. Humans also make plans that depend on past experience by simulating different scenarios, which is called prospective optimization. The same brain structures in the cortex and basal ganglia that are active online during optimal behavior are also active offline during prospective optimization. The emergence of general principles and algorithms for goal-directed behavior has consequences for the development of autonomous devices in engineering applications. PMID:25328167

Sejnowski, Terrence J.; Poizner, Howard; Lynch, Gary; Gepshtein, Sergei; Greenspan, Ralph J.

2014-01-01

300

Polyethylene fiber drawing optimization  

E-print Network

Polymer fiber drawing creates fibers with enhanced thermal conductivity and strength compared to bulk polymer because drawing aligns the molecular chains. I optimize the polymer fiber drawing method in order to achieve ...

Chiloyan, Vazrik

2011-01-01

301

Students' Goal Achievement: Exploring Individual and Situational Factors  

ERIC Educational Resources Information Center

Introduction: This paper reports a preliminary investigation of the individual and situational factors affecting goal achievement in a psychology student population. The impact of normative information on goal achievement is considered in relation to goal commitment, optimism, gender and academic setting. Method: Psychology students (n=121) from…

Derrer-Rendall, Nicola; Wesson, Caroline; Anderson, Lindsey; Bould, Emma

2009-01-01

302

Assisting Pupils in Mathematics Achievement (The Common Core Standards)  

ERIC Educational Resources Information Center

Mathematics teachers must expect reasonably high standards of achievement from pupils. Too frequently, pupils attain at a substandard level and more optimal achievement is necessary. Thus, pupils should have self esteem needs met in the school and classroom setting. Thus, learners feel that mathematics is worthwhile and effort must be put forth to…

Ediger, Marlow

2011-01-01

303

HEPEX - achievements and challenges!  

NASA Astrophysics Data System (ADS)

HEPEX is an international initiative bringing together hydrologists, meteorologists, researchers and end-users to develop advanced probabilistic hydrological forecast techniques for improved flood, drought and water management. HEPEX was launched in 2004 as an independent, cooperative international scientific activity. During the first meeting, the overarching goal was defined as: "to develop and test procedures to produce reliable hydrological ensemble forecasts, and to demonstrate their utility in decision making related to the water, environmental and emergency management sectors." The applications of hydrological ensemble predictions span across large spatio-temporal scales, ranging from short-term and localized predictions to global climate change and regional modeling. Within the HEPEX community, information is shared through its blog (www.hepex.org), meetings, testbeds and intercompaison experiments, as well as project reportings. Key questions of HEPEX are: * What adaptations are required for meteorological ensemble systems to be coupled with hydrological ensemble systems? * How should the existing hydrological ensemble prediction systems be modified to account for all sources of uncertainty within a forecast? * What is the best way for the user community to take advantage of ensemble forecasts and to make better decisions based on them? This year HEPEX celebrates its 10th year anniversary and this poster will present a review of the main operational and research achievements and challenges prepared by Hepex contributors on data assimilation, post-processing of hydrologic predictions, forecast verification, communication and use of probabilistic forecasts in decision-making. Additionally, we will present the most recent activities implemented by Hepex and illustrate how everyone can join the community and participate to the development of new approaches in hydrologic ensemble prediction.

Pappenberger, Florian; Ramos, Maria-Helena; Thielen, Jutta; Wood, Andy; Wang, Qj; Duan, Qingyun; Collischonn, Walter; Verkade, Jan; Voisin, Nathalie; Wetterhall, Fredrik; Vuillaume, Jean-Francois Emmanuel; Lucatero Villasenor, Diana; Cloke, Hannah L.; Schaake, John; van Andel, Schalk-Jan

2014-05-01

304

Expert system for controlling plant growth in a contained environment  

NASA Technical Reports Server (NTRS)

In a system for optimizing crop growth, vegetation is cultivated in a contained environment, such as a greenhouse, an underground cavern or other enclosed space. Imaging equipment is positioned within or about the contained environment, to acquire spatially distributed crop growth information, and environmental sensors are provided to acquire data regarding multiple environmental conditions that can affect crop development. Illumination within the contained environment, and the addition of essential nutrients and chemicals are in turn controlled in response to data acquired by the imaging apparatus and environmental sensors, by an ''expert system'' which is trained to analyze and evaluate crop conditions. The expert system controls the spatial and temporal lighting pattern within the contained area, and the timing and allocation of nutrients and chemicals to achieve optimized crop development. A user can access the ''expert system'' remotely, to assess activity within the growth chamber, and can override the ''expert system''.

May, George A. (Inventor); Lanoue, Mark Allen (Inventor); Bethel, Matthew (Inventor); Ryan, Robert E. (Inventor)

2009-01-01

305

Expert system for controlling plant growth in a contained environment  

NASA Technical Reports Server (NTRS)

In a system for optimizing crop growth, vegetation is cultivated in a contained environment, such as a greenhouse, an underground cavern or other enclosed space. Imaging equipment is positioned within or about the contained environment, to acquire spatially distributed crop growth information, and environmental sensors are provided to acquire data regarding multiple environmental conditions that can affect crop development. Illumination within the contained environment, and the addition of essential nutrients and chemicals are in turn controlled in response to data acquired by the imaging apparatus and environmental sensors, by an "expert system" which is trained to analyze and evaluate crop conditions. The expert system controls the spatial and temporal lighting pattern within the contained area, and the timing and allocation of nutrients and chemicals to achieve optimized crop development. A user can access the "expert system" remotely, to assess activity within the growth chamber, and can override the "expert system".

May, George A. (Inventor); Lanoue, Mark Allen (Inventor); Bethel, Matthew (Inventor); Ryan, Robert E. (Inventor)

2011-01-01

306

Distributive Politics and Economic Growth  

Microsoft Academic Search

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

Alberto Alesina

1994-01-01

307

Achievement Motivation: An Investigation of Adolescents' Achievement Patterns.  

ERIC Educational Resources Information Center

Levels of general and area-specific achievement motivation for adolescents of varying backgrounds were assessed. General measures of achievement motivation revealed significant differences by race, sex, and social class. These factors exercised great influence on specific types of achievement behavior. (Author/DWH)

Castenell, Louis A.

1983-01-01

308

Development and optimization of a secure injection CVD process to grow aligned carbon nanotubes on large substrates  

NASA Astrophysics Data System (ADS)

Growth of aligned carbon nanotubes (CNT) by a secure injection CVD process on large quartz substrates and carbon fiber (CF) cloths has been reported in this study. Adjustments of CVD setup and synthesis parameters have been achieved to control the CNT growth in terms of homogeneous covering of the substrates and to tailor the length of CNT. Two parameters have been optimized such as the precursor feeding rate per reactor surface unit and the carrier gas flow rate.

Patel, S.; Magga, Y.; Belkady, L.; Hibert, E.; Porterat, D.; Boulanger, P.; Pinault, M.; Mayne-L'Hermite, M.

2013-04-01

309

Structural, Optical and Electrical Characterization of Nano-Structured ZnO Thin Films Deposited by Solution Growth Technique  

Microsoft Academic Search

Successive ionic layer adsorption and reaction technique (SILAR) and solution growth technique have been applied to deposit thin films on amorphous glass substrates. Various parameters, like concentration of complexing agent, pH of the solution, deposition temperature, time, have been optimized to achieve good quality films. Films grown by SILAR method have been found to be non-uniform as confirmed by SEM,

A. K. Singh; S. B. Patil; V. C. Janu

2008-01-01

310

Gear optimization  

NASA Technical Reports Server (NTRS)

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.

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

1988-01-01

311

PHYSICAL FITNESS AND ACADEMIC ACHIEVEMENT  

Microsoft Academic Search

Grissom JB. Physical Fitness And Academic Achievement. JEPonline 2005;8(1):11-25 . The purpose of this study was to evaluate the relationship between physical fitness and academic achievement. To do so, scores on the FITNESSGRAM®, a physical fitness test, were compared to reading and mathematics scores on the Stanford Achievement Test 9th edition, a standardized norm-referenced achievement test. Subjects were all 5th,

Robert Robergs; Grissom JB

312

Proving Goal Achievability Fangzhen Lin  

E-print Network

Proving Goal Achievability Fangzhen Lin Department of Computer Science and Engineering Hong Kong subsets, then the problem is equivalent to checking whether the goal is achievable in every initial state that this result provides an effective way of proving goal achievability, and illustrate it through some ex- amples

Wu, Dekai

313

[Research Reports on Academic Achievement.  

ERIC Educational Resources Information Center

Four counselors studied the relation between achievement and choice of major, achievement and motivation, counseling and motivation, and achievement and employment. To see if those with definite majors or career choices in mind did better than those without, 300 students were tested according to the certainty of their choice. No significant…

Latts, Sander; And Others

1969-01-01

314

Optimal Contracts for Central Bankers  

Microsoft Academic Search

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

Carl E Walsh

1995-01-01

315

Congestion Control to Achieve Optimal Broadcast Efficiency in VANETs  

E-print Network

efficiency has also been studied ex- tensively in wireless local area networks [12]­[15]. While@u.washington.edu Abstract--In a vehicular network, every vehicle broadcasts update messages that contain location and speed ad hoc network (VANET) is a promising form of mobile ad hoc network, in which vehicles are equipped

Roy, Sumit

316

Integrating Psychosocial and Behavioral Interventions to Achieve Optimal Rehabilitation Outcomes  

Microsoft Academic Search

Introduction: Psychosocial factors are important contributors to work disability associated with musculoskeletal conditions. The primary objectives of this paper were 1) to describe different psychosocial interventions that have been developed to prevent prolonged work disability, and 2) to identify future research directions that might enhance the impact of programs targeting psychosocial risk factors for work disability. Methods: Selective review of

Michael Jl Sullivan; Michael Feuerstein; Robert Gatchel; Steven J. Linton; Glenn Pransky

2005-01-01

317

Achieving Better Building Performance and Savings Using Optimal Control Strategies  

E-print Network

The Continuous Commissioning (CCSM) process has become a very important energy conservation topic for new and existing commercial buildings. This process can yield substantial operating savings, improved indoor air quality, and enhanced occupant...

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

2003-01-01

318

Multiphase NanoComposite Coatings for Achieving Energy Optimization  

Microsoft Academic Search

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

Jose Nainaparampil

2012-01-01

319

Optimizing Production of Hydroquinone Achieves Increased Yield and Energy Efficiency  

E-print Network

definition ? Risk assessment ? In order to move past the cultural barriers, a detailed risk assessment was essential for stakeholder buy-in. ? The Failure Modes and Effects Analysis (FMEA) tool was used to document and evaluate potential risks.... ? Reliable supply at high level of p-DIPB ? Peroxides degradation at higher temperatures ? Inventory management ? Labor ? operations and packaging (contractors) ? FMEA promoted understanding of the risks. Project definition ? Risk management ? Performed...

Gross, S.

320

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

E-print Network

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.

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

2012-01-01

321

Autoimmune control of lesion growth in CNS with minimal damage  

NASA Astrophysics Data System (ADS)

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.

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

2013-07-01

322

Affective Processes and Academic Achievement.  

ERIC Educational Resources Information Center

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)

Feshbach, Norma Deitch; Feshbach, Seymour

1987-01-01

323

Development of intelligent robots - Achievements and issues  

NASA Astrophysics Data System (ADS)

A flexible, intelligent robot is regarded as a general purpose machine system that may include effectors, sensors, computers, and auxiliary equipment and, like a human, can perform a variety of tasks under unpredictable conditions. Development of intelligent robots is essential for increasing the growth rate of today's robot population in industry and elsewhere. Robotics research and development topics include manipulation, end effectors, mobility, sensing (noncontact and contact), adaptive control, robot programming languages, and manufacturing process planning. Past achievements and current issues related to each of these topics are described briefly.

Nitzan, D.

1985-03-01

324

Time use and change in academic achievement: A longitudinal follow-up  

Microsoft Academic Search

As a follow-up of the research of Smith in 1990, academic achievement results from two years later are added to the data for 1208 of the 1584 seventh and ninth graders for whom Smith studied relationships between achievement and time use. Growth in academic achievement over two years, like contemporaneous achievement, is not positively related to time spent on homework

Thomas Ewin Smith

1992-01-01

325

Poor Results for High Achievers  

ERIC Educational Resources Information Center

Three million students in the United States are classified as gifted, yet little is known about the effectiveness of traditional gifted and talented (G&T) programs. In theory, G&T programs might help high-achieving students because they group them with other high achievers and typically offer specially trained teachers and a more advanced…

Bui, Sa; Imberman, Scott; Craig, Steven

2012-01-01

326

Junior Achievement Middle Grades Program  

NSDL National Science Digital Library

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.

JA Worldwide

327

VEHICLE NETWORKS: ACHIEVING REGULAR FORMATION  

E-print Network

VEHICLE NETWORKS: ACHIEVING REGULAR FORMATION MADALENA CHAVES, ROBERT DAY, LUCIA GOMEZ a network of vehicles exchanging information among themselves with the intention of achieving a specified the performance of the vehicle network. A stochastic model for information flow is also considered, allowing

328

Some characteristics of achievement motivation  

Microsoft Academic Search

An independent measure of motivation and a performance test were given under three different verbally created conditions of achievement motivation: relaxed, task motivated, and extrinsically motivated. Found an increase in achievement motivation as a function of both previous motivational level and the experimental conditions, and that performance scores were more closely related to motivation scores than to the experimental conditions.

Elizabeth G. French

1955-01-01

329

Teaming and Achievement. Research Brief  

ERIC Educational Resources Information Center

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…

Muir, Mike

2003-01-01

330

General Achievement Trends: New Jersey  

ERIC Educational Resources Information Center

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…

Center on Education Policy, 2009

2009-01-01

331

Teaching the Low Level Achiever.  

ERIC Educational Resources Information Center

Intended for teachers of the English language arts, the articles in this issue offer suggestions and techniques for teaching the low level achiever. Titles and authors of the articles are as follows: (1) "A Point to Ponder" (Rachel Martin); (2) "Tracking: A Self-Fulfilling Prophecy of Failure for the Low Level Achiever" (James Christopher Davis);…

Salomone, Ronald E., Ed.

1986-01-01

332

Understanding and Fostering Achievement Motivation  

ERIC Educational Resources Information Center

Fostering achievement motivation in students is a primary objective of school administrators. A good deal of focus goes to promoting motivation when creating school climate, structuring grading systems, and designing awards programs and policies that recognize effort and achievement. It is also a primary issue in counseling and interventions for…

Klose, Laurie McGarry

2008-01-01

333

Superintendent Tenure and Student Achievement  

ERIC Educational Resources Information Center

A correlational research design was used to examine the influence of superintendent tenure on student achievement in rural Appalachian Kentucky school districts. Superintendent tenure was compared to aggregated student achievement scores for 2011 and to changes in students' learning outcomes over the course of the superintendents' tenure. The…

Simpson, Jennifer

2013-01-01

334

General Achievement Trends: North Carolina  

ERIC Educational Resources Information Center

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…

Center on Education Policy, 2009

2009-01-01

335

Stress Correlates and Academic Achievement.  

ERIC Educational Resources Information Center

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…

Bentley, Donna Anderson; And Others

336

APS Topical Conference on Shock Compression of Condensed Matter, 13-18 August 1995, Seattle, WA. NUMERICAL OPTIMIZATION OF IGNITION AND GROWTH  

E-print Network

), and explosively formed projectile (EFP) modeling (3,4,5). These efforts not only demonstrated the utility explosive PAX2A. The NLQPEB nonlinear optimization program has been recently coupled to the LLNL developed to explosives products equation of state parameterization (1), shaped charge analytic design (2

Grantham, Walter J.

337

Treatment of Escherichia coli O157:H7 with lactic acid, neutralized electrolyzed oxidizing water and chlorine dioxide followed by growth under sub-optimal conditions of temperature, pH and modified atmosphere.  

PubMed

The utilization of sub-lethal decontamination treatments gains more and more interest due to the increased consumers' demand for fresh, minimally processed and convenient food products. These products rely on cold chain and hurdle (combination) technology to provide microbiological safety and quality during their shelf life. To investigate the ability of surviving cells to resuscitate and grow in a food simulating environment, sub-lethal decontamination treatments were coupled with subsequent storage under sub-optimal growth conditions. For this purpose chlorine dioxide (ClO2) and neutralized electrolyzed oxidizing water (NEW)-treated cultures of Escherichia coli O157:H7 were inoculated in TSB-YE of pH 5.8 and aw 0.99, and stored at 10 degrees C, 12.5 degrees C and 15 degrees C, under four different atmospheres (0%, 30% and 60% CO2 balanced with N2, and air). Due to the severity of injury, lactic acid-treated cells were inoculated in TSB-YE pH 7.0. Data obtained reveal that the fraction of sub-lethally injured E. coli O157:H7 undergoes an additional inhibitory effect during the storage period under of sub-optimal conditions. Observed extension in the lag growth phase was a direct consequence prior sub-lethal injury. The effects of liquid ClO2 and NEW were less pronounced in comparison to lactic acid. The current study signifies the potential utilization of appropriate combination of different extrinsic and intrinsic factors in the elimination or growth inhibition of food-borne pathogens. PMID:19527839

Smigic, Nada; Rajkovic, Andreja; Antal, Eszter; Medic, Helga; Lipnicka, Barbara; Uyttendaele, Mieke; Devlieghere, Frank

2009-09-01

338

Gender Difference in Insulin-Like Growth Factor I Response to Growth Hormone (GH) Treatment in GH-Deficient Adults: Role of Sex Hormone Replacement  

Microsoft Academic Search

GH production in healthy women is about thrice that in men. Yet insulin-like growth factor I (IGF-I) levels are similar, suggesting a lower responsivity to GH in women. In untreated GH-deficient adults, basal IGF-I levels are reportedly lower in females than in males, and the therapeutic recombinant human GH (rhGH) dose required to achieve optimal IGF-I levels is higher in

A. G. H. SMALS

339

Growth Kinetics in Epitaxial Growth  

NASA Astrophysics Data System (ADS)

Growth kinetics in heteroepitaxial growth are related to the nucleation and growth of atomic-height islands during the deposition of a material on a dissimilar substrate. Experimental measurements of the initial morphology of CaF_2 films deposited on Si(111) substrates were performed. These measurements consisted of photoemission spectroscopy and diffraction, which give sub-nanometer scale information averaged over the entire sample, and plan-view transmission electron microscopy, which gives localized information on a scale of several nanometers. These results, combined with others in the literature, revealed four distinct growth morphologies dependent on the deposition rate, substrate temperature and spacing between atomic-height steps on the surface, two of which had not been previously explained. A model based on two extant theories of homoepitaxial growth kinetics was developed to explain the different observed growth morphologies for the heteroepitaxial system CaF_2/Si(111). The first theory deals with whether the initial nucleation will occur at substrate steps or through adatom collisions on flat terraces, while the second deals with the nucleation of subsequent layers as these initial atomic islands increase in size. In extending these theories to heteroepitaxy, very different rates of upper-layer nucleation for the different size islands that nucleated at steps and on terraces are predicted. By applying this theory to CaF_2/Si(111), the diffusion barriers for CaF_2 molecule migration both on the reacted Si-Ca-F interface layer and on subsequent CaF_2 layers was extracted. The four different growth morphologies are explained within a common framework. The theory is quite general, and should apply to most heteroepitaxial systems. These theories were extended to predict a means by which the upper-layer nucleation may be inhibited while the underlying layer is completed. This method involves initiating the growth at conditions favoring many, small islands on atomic terraces, and then completing the growth at conditions inhibiting upper-layer nucleation (lower flux and/or higher temperature). A general formula for either homoepitaxy or heteroepitaxy was developed for the optimal flux and temperature variation during each monolayer to fabricate a flat film in the minimum amount of time.

Hessinger, Uwe

340

Optimization of experimental and modelling parameters for the differentiation of beverage spoiling yeasts by Matrix-Assisted-Laser-Desorption/Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF MS) in response to varying growth conditions.  

PubMed

The growth of spoiling yeasts in beverages results in reduced quality, economic and image losses. Therefore, biochemical and DNA-based identification methods have been developed but are mostly time-consuming and laborious. Matrix-Assisted-Laser-Desorption/Ionization-Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) could deliver discriminative peptide mass fingerprints within minutes and could thus be a rapid and reliable tool for identification and differentiation. However, routine analysis of yeasts by MALDI-TOF MS is yet impaired by low reproducibility and effects of different physiological states of organisms on the reliability of the identification method are still controversial. The aim of this study was to optimize sample preparation and measurement parameterization using three spoilage yeasts (Saccharomyces cerevisiae var. diastaticus, Wickerhamomyces anomalus and Debaryomyces hansenii). The influence of environmental or physiological parameters including oxygen availability, different nutrients, cell density and growth phase were analysed and revealed small differences in mass fingerprints. Yeasts grown in the presence or absence of oxygen were precisely differentiated along these differences in mass fingerprints and a crude classification of growth phase was possible. Cell concentration did not affect the spectra distinctly, neither qualitatively nor quantitatively, and an influence of available nutrients could not be measured in each case. However, core mass peaks remained constant under all tested conditions enabling reliable identification. PMID:24010620

Usbeck, Julia C; Kern, Carola C; Vogel, Rudi F; Behr, Jürgen

2013-12-01

341

An integrated microalgal growth model and its application to optimize the biomass production of Scenedesmus sp. LX1 in open pond under the nutrient level of domestic secondary effluent.  

PubMed

Microalgal growth is the key to the coupled system of wastewater treatment and microalgal biomass production. In this study, Monod model, Droop model and Steele model were incorporated to obtain an integrated growth model describing the combined effects of nitrogen, phosphorus and light intensity on the growth rate of Scenedesmus sp. LX1. The model parameters were obtained via fitting experimental data to these classical models. Furthermore, the biomass production of Scenedesmus sp. LX1 in open pond under nutrient level of secondary effluent was analyzed based on the integrated model, predicting a maximal microalgal biomass production rate about 20 g m(-2) d(-1). In order to optimize the biomass production of open pond the microalgal biomass concentration, light intensity on the surface of open pond, total depth of culture medium and hydraulic retention time should be 500 g m(-3), 16,000 lx, 0.2 m and 5.2 d in the conditions of this study, respectively. PMID:23891148

Wu, Yin-Hu; Li, Xin; Yu, Yin; Hu, Hong-Ying; Zhang, Tian-Yuan; Li, Feng-Min

2013-09-01

342

Using Design To Achieve Sustainability  

EPA Science Inventory

Sustainability is defined as meeting the needs of this generation without compromising the ability of future generations to meet their needs. This is a conditional statement that places the responsibility for achieving sustainability squarely in hands of designers and planners....

343

Optimized solar module design  

NASA Technical Reports Server (NTRS)

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.

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

1978-01-01

344

Optimal Weight Gain  

Microsoft Academic Search

Optimal birth weight and outcome are influenced by maternal weight gain. Low gestational weight gain is associated with poor\\u000a fetal growth and risk of preterm delivery. Excessive weight gain affects infant growth, body fatness in childhood, and the\\u000a potential for postpartum weight retention and future obesity. Guidelines from the Institute of Medicine recommend that a woman\\u000a with a normal body

Grace A. Falciglia; Kristin H. Coppage

345

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

PubMed Central

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

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

2014-01-01

346

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

Microsoft Academic Search

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

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

2004-01-01

347

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

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

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

1996-01-01

348

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

ERIC Educational Resources Information Center

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…

Collins, Natalie M.

2012-01-01

349

Reading Achievement Trajectories for Students with Learning Disabilities during the Elementary School Years  

ERIC Educational Resources Information Center

Using hierarchical linear modeling and longitudinal data from the first 6 waves of the Early Childhood Longitudinal Study-Kindergarten cohort, the authors examined reading achievement and growth rates by learning disability (LD) subgroup. The 2-level (time-student) growth curve model indicated that lower levels of reading achievement were already…

Judge, Sharon; Bell, Sherry Mee

2011-01-01

350

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

ERIC Educational Resources Information Center

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…

Robinson, Keith; Mueller, Anna S.

2014-01-01

351

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

ERIC Educational Resources Information Center

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…

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

2012-01-01

352

Growth Problems  

MedlinePLUS

... a more normal growth pattern. Continue What Are Growth Disorders? Teens may have growth problems for other ... Most cases of dwarfism are genetic. Back Continue Growth Hormone Deficiency One growth disorder that is specific ...

353

Reading Achievement in 1979 vs. Achievement in the Fifties.  

ERIC Educational Resources Information Center

A study of the reading achievement of sixth-grade students in the Tampa Bay area of Florida shows average and above average students doing better on 1978 standardized reading tests than on tests from the 1950s, while below average students do better on the earlier tests. (PGD)

Elligett, Jane; Tocco, Thomas S.

1980-01-01

354

Lags in Minority Achievement Defy Traditional Explanations. The Achievement Gap.  

ERIC Educational Resources Information Center

This second in a four-part series on why academic achievement gaps exist notes that standard explanations for why minority students trail behind non-Hispanic whites are not good enough, suggesting that no single explanation for the gap exists, but instead a multitude of factors are influential. Poverty, though not the single most important cause,…

Viadero, Debra; Johnston, Robert C.

2000-01-01

355

Pinch technology/process optimization  

SciTech Connect

Improved process efficiency is of great importance to electric utilities and their industrial customers. It enhances company profitability, thereby fostering load retention and strategic load growth. Moreover, the technical means of achieving improved efficiency can significantly impact utility load shapes. By understanding the energy use patterns and options in an industrial facility, the utility and industrial user can work together to define mutually beneficial investment and operating decisions and to clarify how the decisions might be impacted by existing or alternative energy prices. Efforts to achieve such understanding are facilitated by using pinch technology, an innovative and highly effective methodology for systematically analyzing total industrial sites. This report documents a series of twelve industrial process optimization case studies. The studies were carried out using pinch technology. '' Each study was cosponsored by the industrial site's local electric utility. The twelve studies are follows: (1) pulp and paper, (2) refinery, (3) refinery, (4) yeast, (5) soups/sauces, (6) cellulose- acetate, (7) refinery, (8) chemicals, (9) gelatin-capsules, (10) refinery, (11) brewery, (12) cereal grains.

Not Available

1992-12-01

356

SMART GROWTH TOOLS FOR TRANSPORTATION  

Microsoft Academic Search

Smart growth has become popular in recent years as a way to improve quality of life and efficient use of available resources. Many communities have embarked on efforts to pursue smart growth. However, implementation of smart growth has been harder to achieve. This feature provides descriptions of a number of tools that can help to implement the transportation components (and

Brian S Bochner

2000-01-01

357

Porous plant growth media design considerations for Lunar and Martian habitats  

Microsoft Academic Search

Lunarand Martian-based plant growth facilities pose novel challenges to the design and management of porous medium-based root-zone environments. An optimized 10 cm tall root zone on earth would require 60 cm to achieve the same relative water content distribution in a lunar greenhouse. For adapting lunar gravity to the desired size (e.g., 10 cm), one could theoretically scale the water

Scott Jones; Robert Heinse; Bruce Bugbee; Dani; Gail Bingham

2008-01-01

358

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.

359

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

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

360

CCMR: Characterizing Growth of Single Cell Amoeba  

NSDL National Science Digital Library

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 amoebaâs different growth phases.

Yavitt, Ben

2010-08-15

361

Achieving Biologically Stable Drinking Water  

Microsoft Academic Search

Biologically stable water does not promote the growth of microorganisms during its distribution. This article combines microbiological theory and European practice to demonstrate how biological processes within a water treatment plant can remove the organic and inorganic substrates that cause or contribute to biological instability. Theory and practice indicate that ammonium and manganese ions and biodegradable organic compounds can be

Bruce E. Rittmann; Vernon L. Snoeyink

1984-01-01

362

Goal Setting to Achieve Results  

ERIC Educational Resources Information Center

Both districts and individual schools have a very clear set of goals and skills for their students to achieve and master. In fact, except in rare cases, districts and schools develop very detailed goals they wish to pursue. In most cases, unfortunately, only the teachers and staff at a particular school or district-level office are aware of the…

Newman, Rich

2012-01-01

363

The Achievement-Assessment Link  

ERIC Educational Resources Information Center

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…

Wallace, Virginia; Husid, Whitney

2011-01-01

364

Can Judges Improve Academic Achievement?  

ERIC Educational Resources Information Center

Over the last 3 decades student achievement has remained essentially unchanged in the United States, but not for a lack of spending. Over the same period a myriad of education reforms have been suggested and per-pupil spending has more than doubled. Since the 1990s the education reform attempts have frequently included judicial decisions to revise…

Greene, Jay P.; Trivitt, Julie R.

2008-01-01

365

Helping Rural Schools Achieve Success.  

ERIC Educational Resources Information Center

Senator Collins of Maine plans to fight for proper federal funding of the Rural Education Achievement Program (REAP) that allows rural schools to combine federal funding sources. Collins, and Senator Dianne Feinstein, will soon introduce legislation that will eliminate inequities in the current Social Security law that penalize teachers and other…

Collins, Susan

2003-01-01

366

Sociocultural Variation in Literacy Achievement  

ERIC Educational Resources Information Center

The purpose of this study was to describe the variations in literacy achievement among native and non-native upper primary school children (grades three to six) in the Netherlands. Various measures of word decoding, reading literacy and writing skill were collected from 1091 native Dutch children, 753 children with a former Dutch colonial…

Verhoeven, Ludo

2006-01-01

367

Meeting a Math Achievement Crisis  

ERIC Educational Resources Information Center

An urban community spotlighted declining mathematics achievement and took some measures, in which the students' performance increased substantially. The Benjamin Banneker Charter Public School in Cambridge, Massachusetts, engaged the entire community and launched the campaign called "Math Everywhere", which changed Benjamin Banneker's culture as…

Jennings, Lenora; Likis, Lori

2005-01-01

368

School Desegregation and Black Achievement.  

ERIC Educational Resources Information Center

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…

Cook, Thomas; And Others

369

Socioeconomic Determinants of Academic Achievement  

ERIC Educational Resources Information Center

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…

Tomul, Ekber; Savasci, Havva Sebile

2012-01-01

370

Teacher Dispositions and Student Achievement  

ERIC Educational Resources Information Center

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.…

Vaughn, Kathleen Adams

2012-01-01

371

Academic Achievement in Effective Schools  

ERIC Educational Resources Information Center

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'…

Basque, Marc; Bouchamma, Yamina

2013-01-01

372

Teachers, Schools, and Academic Achievement  

Microsoft Academic Search

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

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

2002-01-01

373

Achieving Results in MBA Communication.  

ERIC Educational Resources Information Center

Describes how Rice University's Jones Graduate School of Management achieves their mission for the communication program. Discusses three keys to the success of the program: individual coaching, integrated team instruction, and constant assessment of the students and the program. Presents an overview of the program. (SG)

Barrett, Deborah J.

2002-01-01

374

ACHIEVING DEXTEROUS MANIPULATION FOR MINIMALLY  

E-print Network

ACHIEVING DEXTEROUS MANIPULATION FOR MINIMALLY INVASIVE SURGICAL ROBOTS THROUGH THE USE;Hydraulics offers advantages for surgical manipulators. 5 #12;6 #12;The components are housed within the manipulator itself. 7 #12;8 #12;The backbone is assumed to take the lowest energy shape. 9 #12;The backbone

Wu, Mingshen

375

Do Teachers Favor High Achievers?  

ERIC Educational Resources Information Center

The study found that teachers of seventh grade mathematics classes interacted less frequently and for less time with the best students. At the grade 10 level teachers also spent less time interacting with high achievers but called on them more frequently in some situations. Sex differences were not observed. (Author/DB)

Leder, Gilah C.

1988-01-01

376

Sociodemographic Moderators of Middle School Transition Effects on Academic Achievement  

ERIC Educational Resources Information Center

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…

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

2015-01-01

377

Growth and maturation of oocytes in vitro.  

PubMed

The development of technologies to grow and mature oocytes from the most abundant primordial follicles holds many attractions for clinical practice, animal production technology and research. However, despite much research attention, it has proved difficult to grow follicles from early stages to maturity in vitro, as relatively little is known about the biology of oogenesis. It is clear that throughout oocyte development in vivo, follicle cell support is fundamental to provide the germ cell with nutrients and growth regulators to ensure progression through the protracted growth phase. Conversely, the oocyte actively promotes growth and differentiation of the follicular cells. Both of these characteristics must be mimicked in vitro. Replication of the normal follicular growth span from the primordial to Graafian follicle stages and the changes in the trophic requirements of the cells, cellular interactions, morphogenesis and the sheer increase in bulk as the antrum forms present major challenges for follicle culture technology. These observations could explain why methods that have proved successful for the culture of isolated rodent follicles are unable to support the growth of larger human and ruminant follicles in vitro and are incompatible with the requirements for primordial follicle growth activation. At present, the best option available for the complete growth and maturation of oocytes in vitro is to develop an extended multistage culture strategy which will provide a complex support system that closely resembles the ovary in vivo. In an attempt to achieve this goal primordial follicle growth is first initiated and maintained to the preantral stages through the culture of thin slices of ovarian cortex. The isolation and continued culture of these preantral follicles will support antral cavity formation and the induction of differentiated function in the somatic cell compartment. Finally, after exposure to an appropriate steroid milieu in vitro it should be possible to induce nuclear and cytoplasmic maturation in the fully grown oocytes. The prospects of succeeding at each stage, and of finally producing a fertile gamete, are likely to be increased by preserving cellular interactions and the phenotype of follicle cells as these provide the physiological environment in which oocytes develop. Although the technology for the in vitro maturation (IVM) of fully grown oocytes has been exploited successfully in ruminants, in human assisted reproduction IVM is still experimental as the efficiency of IVM is low and only a small number of pregnancies and live births have been reported. Thus, although complete in vitro growth and maturation may be achieved eventually, immediate goals must include the optimization of methods for isolating and culturing oocytes at both ends of the size spectrum and the full evaluation of the normality of the oocytes grown for extended periods in vitro. PMID:14635954

Picton, H M; Danfour, M A; Harris, S E; Chambers, E L; Huntriss, J

2003-01-01

378

Supply-Chain Optimization Template  

NASA Technical Reports Server (NTRS)

The Supply-Chain Optimization Template (SCOT) is an instructional guide for identifying, evaluating, and optimizing (including re-engineering) aerospace- oriented supply chains. The SCOT was derived from the Supply Chain Council s Supply-Chain Operations Reference (SCC SCOR) Model, which is more generic and more oriented toward achieving a competitive advantage in business.

Quiett, William F.; Sealing, Scott L.

2009-01-01

379

Utility Theory for Evaluation of Optimal Process Condition of SAW: A Multi-Response Optimization Approach  

NASA Astrophysics Data System (ADS)

Multi-objective optimization problem has been solved in order to estimate an optimal process environment consisting of optimal parametric combination to achieve desired quality indicators (related to bead geometry) of submerged arc weld of mild steel. The quality indicators selected in the study were bead height, penetration depth, bead width and percentage dilution. Taguchi method followed by utility concept has been adopted to evaluate the optimal process condition achieving multiple objective requirements of the desired quality weld.

Datta, Saurav; Biswas, Ajay; Bhaumik, Swapan; Majumdar, Gautam

2011-01-01

380

Utility Theory for Evaluation of Optimal Process Condition of SAW: A Multi-Response Optimization Approach  

SciTech Connect

Multi-objective optimization problem has been solved in order to estimate an optimal process environment consisting of optimal parametric combination to achieve desired quality indicators (related to bead geometry) of submerged arc weld of mild steel. The quality indicators selected in the study were bead height, penetration depth, bead width and percentage dilution. Taguchi method followed by utility concept has been adopted to evaluate the optimal process condition achieving multiple objective requirements of the desired quality weld.

Datta, Saurav [Department of Mechanical Engineering, National Institute of Technology, Rourkela, Orissa-769008 (India); Biswas, Ajay; Bhaumik, Swapan [Department of Mechanical Engineering, National Institute of Technology, Agartala, Barjala, Tripura (W), Pin-799055 (India); Majumdar, Gautam [Department of Mechanical Engineering, Jadavpur University, Raja S. C. Mallik Road, Kolkata-700032 (India)

2011-01-17

381

Design issues for population growth models  

PubMed Central

We briefly review and discuss design issues for population growth and decline models. We then use a flexible growth and decline model as an illustrative example and apply optimal design theory to find optimal sampling times for estimating model parameters, specific parameters and interesting functions of the model parameters for the model with two real applications. Robustness properties of the optimal designs are investigated when nominal values or the model is mis-specified, and also under a different optimality criterion. To facilitate use of optimal design ideas in practice, we also introduce a website for generating a variety of optimal designs for popular models from different disciplines. PMID:21647244

López Fidalgo, J.; Ortiz Rodríguez, I.M.

2010-01-01

382

Birth weight and academic achievement in childhood.  

PubMed

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

Chatterji, Pinka; Kim, Dohyung; Lahiri, Kajal

2014-09-01

383

Mathematics, Engineering, Science Achievement (MESA)  

NSDL National Science Digital Library

California's Mathematics, Engineering, Science Achievement (MESA), founded in 1970, assists students to become highly trained technological professionals by serving educationally disadvantaged students and, to the extent possible by law, emphasizes participation by students from groups with low eligibility rates for four-year colleges. Learn about MESA initiatives such as its Schools Program (MSP), Success Through Collaboration (MESA STC), California Community College Program (CCCP), and Engineering Program (MEP).

2007-09-05

384

Leading Change for Student Achievement  

Microsoft Academic Search

This article argues that in order to meet the heightened expectations now placed on schools in a knowledge society, avoid\\u000a cultural resistance to positive change by those in schools and achieve improved student outcomes (attitudinal, behavioural\\u000a and academic), we need to not only engage multiple forms of leadership but also have a more complex understanding of relationships\\u000a between these leaderships

Bill Mulford

2006-01-01

385

Achievement motivation and risk preference  

Microsoft Academic Search

Determined relationships among 8 measures of the need for achievement (n Ach) and 12 measures of risk preference, and empirically tested the J. W. Atkinson (see 33:2) risk-taking model involving relationships between the measures. 198 undergraduate males were administered a battery of measures over a 4-wk period. Analysis of the data revealed: (1) low nonsignificant correlations among n Ach measures,

Malcolm S. Weinstein

1969-01-01

386

Probability to Achieve TSC Goal  

Microsoft Academic Search

We propose a probabilistic measure for self-checking (SC) circuits that is analogous to reliability of fault-tolerant systems. This measure is defined as the probability to achieve totally self-checking (TSC) goal at the lth cycle: TSCG(t). TSCG provides insight to the worst case dynamic behavior of SC circuits with respect to the application environment and component failure rates. TSCG surpasses the

Jien-chung Lo; Eiji Fujiwara

1996-01-01

387

School Readiness and Later Achievement  

Microsoft Academic Search

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

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

388

Mouth Growths  

MedlinePLUS

... Symptoms of Oral and Dental Disorders 4 Mouth Growths Growths can originate in any type of tissue ... be Noncancerous (benign) Precancerous (dysplastic) Cancerous (malignant) Noncancerous growths: Most mouth growths are noncancerous. A variety of ...

389

Growth Disorders  

MedlinePLUS

... today's doctors have learned about growth. What's a Growth Disorder? Everyone grows and matures differently. You may ... than other kids the same age. What's Normal Growth? If growth isn't the same for all ...

390

MPQC: Performance Analysis and Optimization  

SciTech Connect

MPQC (Massively Parallel Quantum Chemistry) is a widely used computational quantum chemistry code. It is capable of performing a number of computations commonly occurring in quantum chemistry. In order to achieve better performance of MPQC, in this report we present a detailed performance analysis of this code. We then perform loop and memory access optimizations, and measure performance improvements by comparing the performance of the optimized code with that of the original MPQC code. We observe that the optimized MPQC code achieves a significant improvement in the performance through a better utilization of vector processing and memory hierarchies.

Sarje, Abhinav; Williams, Samuel; Bailey, David

2012-11-30

391

Parametric Design Optimization By Integrating CAD Systems And Optimization Tools  

NASA Astrophysics Data System (ADS)

Designing a cost effective product in minimum time is a complex process. In order to achieve this goal the requirement of optimum designs are becoming more important. One of the time consuming factor in the design optimization cycle is the modifications of Computer Aided Design (CAD) model after optimization. In conventional design optimization techniques the design engineer has to update the CAD model after receiving optimum design from optimization tools. It is worthwhile using parametric design optimization process to minimize the optimization cycle time. This paper presents a comprehensive study to integrate the optimization parameters between CAD system and optimization tools which were driven from a single user environment. Finally, design optimization of a Compressed Natural Gas (CNG) cylinder was implemented as case study. In this case study the optimization tools were fully integrated with CAD system, therefore, all the deliverables including; part design, drawings and assembly can be automatically updated after achieving the optimum geometry having minimum volume and satisfying all imposed constraints.

Rehan, M.; Olabi, A. G.

2009-11-01

392

RF Gun Optimization Study  

SciTech Connect

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.

A. S. Hofler; P. Evtushenko; M. Krasilnikov

2007-08-01

393

RF Gun Optimization Study  

SciTech Connect

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. A genetic algorithm (GA) has been successfully used to optimize DC photo injector designs at Cornell University [1] and Jefferson Lab [2]. We propose to apply GA techniques 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 a system that has been benchmarked with beam measurements and simulation.

Alicia Hofler; Pavel Evtushenko

2007-07-03

394

Achieving Magnet recognition: the process.  

PubMed

Awareness of the Magnet Recognition Program is increasing as health care organizations struggle with the challenges of recruiting and retaining professional nurses and benchmarking nursing-sensitive patient outcomes. Steps in the Magnet process include application, written documentation and evaluation, site visit, decision, and award. These steps are outlined in this article to inform and assist staff nurses in health care organizations that may consider seeking this designation. The more staff nurses know about the elements and process of the Magnet program, the more they can contribute to achieving this prestigious award for quality nursing care. PMID:15916275

Munroe, Donna J; Lash, Ayhan Aytekin

2005-04-01

395

Entrepreneurship and Economic Growth: Some Empirical Studies.  

E-print Network

??abstractThe importance of entrepreneurship for achieving economic growth in contemporary economies is widely recognized, both by policy makers and economists. However, empirical evidence linking entrepreneurship… (more)

A.J. van Stel (André)

2005-01-01

396

General achievable bound of extractable work under feedback control  

NASA Astrophysics Data System (ADS)

A general achievable upper bound of extractable work under feedback control is given, where nonequilibrium equalities are generalized so as to be applicable to error-free measurements. The upper bound involves a term which arises from the part of the process whose information becomes unavailable and is related to the weight of the singular part of the reference probability measure. The obtained upper bound of extractable work is more stringent than the hitherto known one and sets a general achievable bound for a given feedback protocol. Guiding principles of designing the optimal protocol are also suggested. Examples are presented to illustrate our general results.

Ashida, Yuto; Funo, Ken; Murashita, Yûto; Ueda, Masahito

2014-11-01

397

Stripping accumulation and optimization of HIMM synchrotron  

NASA Astrophysics Data System (ADS)

The design of an injection system for a dedicated carbon-ion therapy synchrotron is presented. Improvements to the particle tracking code ACCSIM are developed to support interactions between heavy ions and stripping foil. The three main improvements are concerned with (a) charge exchange between carbon ions and stripping foil; (b) multiple Coulomb scattering of incident heavy ions on stripping foil; and (c) energy loss in particles passing through the foil, and energy-loss straggling. The accumulation process is then simulated, and the parameters related to the injection system are optimized. A gain of about 140 in the number of particles is achieved, and the emittance and momentum spread growth is obtained, together with a central momentum shift. Finally, the superacceptance of the synchrotron, ?-?p/p, is tracked. According to the simulation, 1.35×109 actual particles are stored successfully in the synchrotron.

Chai, Weiping; Yang, Jiancheng; Xia, Jiawen; Yuan, Youjin; Shi, Jian; Yin, Dayu; Li, Peng; Shen, Guodong; Qu, Guofeng; Gao, Xiang

2014-11-01

398

Optimal quantum cloning via spin networks  

E-print Network

In this paper we present an approach to quantum cloning via free dynamical evolution of spin networks. By properly designing the network and the couplings between spins, we show that optimal 1->M phase covariant cloning can be achieved without any external control. 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->2 universal cloning.

Qing Chen; Jianhua Cheng; Ke-Lin Wang; Jiangfeng Du

2005-10-19

399

Methods for true energy-performance optimization  

Microsoft Academic Search

This paper presents methods for efficient energy-performance optimization at the circuit and micro-architectural levels. The optimal balance between energy and performance is achieved when the sensitivity of energy to a change in performance is equal for all the design variables. The sensitivity-based optimizations minimize energy subject to a delay constraint. Energy savings of about 65% can be achieved without delay

Dejan Markovic; Vladimir Stojanovic; Borivoje Nikolic ´; Mark A. Horowitz; Robert W. Brodersen

2004-01-01

400

Achieving permanency for LGBTQ youth.  

PubMed

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

Jacobs, Jill; Freundlich, Madelyn

2006-01-01

401

Export of vacuolar manganese by AtNRAMP3 and AtNRAMP4 is required for optimal photosynthesis and growth under manganese deficiency.  

PubMed

Manganese (Mn) is an essential element, acting as cofactor in numerous enzymes. In particular, a Mn cluster is indispensable for the function of the oxygen-evolving complex of photosystem II. Metal transporters of the Natural Resistance-Associated Macrophage Protein (NRAMP) family have the ability to transport both iron and Mn. AtNRAMP3 and AtNRAMP4 are required for iron mobilization in germinating seeds. The results reported here show that, in adult Arabidopsis (Arabidopsis thaliana) plants, AtNRAMP3 and AtNRAMP4 have an important role in Mn homeostasis. Vacuolar Mn accumulation in mesophyll cells of rosette leaves of adult nramp3nramp4 double mutant plants was dramatically increased when compared with the wild type. This suggests that a considerable proportion of the cellular Mn pool passes through the vacuole and is retrieved in an AtNRAMP3/AtNRAMP4-dependent manner. The impaired Mn release from mesophyll vacuoles of nramp3nramp4 double mutant plants is associated with reduced growth under Mn deficiency. However, leaf AtNRAMP3 and AtNRAMP4 protein levels are unaffected by Mn supply. Under Mn deficiency, nramp3nramp4 plants contain less functional photosystem II than the wild type. These data are consistent with a shortage of Mn to produce functional photosystem II, whereas mitochondrial Mn-dependent superoxide dismutase activity is maintained under Mn deficiency in both genotypes. The results presented here suggest an important role for AtNRAMP3/AtNRAMP4-dependent Mn transit through the vacuole prior to the import into chloroplasts of mesophyll cells. PMID:20181755

Lanquar, Viviane; Ramos, Magali Schnell; Lelièvre, Françoise; Barbier-Brygoo, Hélène; Krieger-Liszkay, Anja; Krämer, Ute; Thomine, Sébastien

2010-04-01

402

Validation and workflow optimization of human epidermal growth factor receptor 2 testing using INFORM HER2 dual-color in situ hybridization.  

PubMed

Human epidermal growth factor receptor 2 (HER2) status is useful for predicting response to trastuzumab. Fluorescence in situ hybridization (FISH) for HER2 gene amplification is accurate but limited because of cost, the need for fluorescence microscopy, the limited assessment of histology, and the fading of its signal over time. Dual-color in situ hybridization (Dual ISH) is fully automated, is viewable by bright-field microscopy, has a stable signal, and has separate colors for HER2 and chromosome 17 signals. HER2 immunohistochemistry (IHC), FISH, and Dual ISH were performed on 101 breast cancer cases. Sixteen of 17 cases with 3+ HER2 by IHC showed gene amplification by FISH, and 15 showed amplification by Dual ISH. Three of the 2+ IHC cases were either amplified or equivocal by Dual ISH. None of the IHC-negative cases were amplified by either FISH or Dual ISH. Dual ISH agreed with FISH in 93% of cases. Among the 6 discrepancies, 4 were for an equivocal result for 1 test compared with either a positive or a negative result for the other test. The average differences in readings between Dual ISH and FISH in the discrepant cases were only 0.02, with a range of -1.37 to 1.85. Turnaround time for FISH as a send-out test from test ordering to reporting averaged 8.27 workdays, whereas the turnaround time for Dual ISH performed in-house averaged 4.94 workdays (P < .0000001). Our results indicated that automated Dual ISH is a useful method for evaluating HER2 status in a clinical setting. PMID:24075600

Lim, Sung-Jig; Cantillep, Alegria; Carpenter, Philip M

2013-11-01

403

Harming the Best: How Schools Affect the Black-White Achievement Gap. NBER Working Paper No. 14211  

ERIC Educational Resources Information Center

Sizeable achievement differences by race appear in early grades, but substantial uncertainty exists about the impact of school quality on the black-white achievement gap and particularly about its evolution across different parts of the achievement distribution. Texas administrative data show that the overall growth in the achievement gap between…

Hanushek, Eric A.; Rivkin, Steven G.

2008-01-01

404

Achieving true sustainability of zoo populations.  

PubMed

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

Lacy, Robert C

2013-01-01

405

Sequential growth and monitoring of a polypyrrole actuator system  

NASA Astrophysics Data System (ADS)

Electroactive polymers (EAPs) have emerged as viable materials in sensing and actuating applications, but the capability to mimic the structure and function of natural muscle is increased due to their ability to permit additional, sequential synthesis steps between stages of actuation. Current work is improving upon the mechanical performance in terms of achievable stresses, strains, and strain rates, but issues still remain with actuator lifetime and adaptability. This work seeks to create a bioinspired polymer actuation system that can be monitored using state estimation and adjusted in vivo during operation. The novel, time-saving process of sequential growth was applied to polymer actuator systems for the initial growth, as well as additional growth steps after actuation cycles. Synthesis of conducting polymers on a helical metal electrode directs polymer shape change during actuation, assists in charge distribution along the polymer for actuation, and as is described in this work, constructs a constant working electrode/polymer connection during operation which allows sequential polymer growth based on a performance need. The polymer system is monitored by means of a reduced-order, state estimation model that works between growth and actuation cycles. In this case, actuator stress is improved between growth cycles. The ability for additional synthesis of the polymer actuator not only creates an actuator system that can be optimized based on demand, but creates a dynamic actuator system that more closely mimics natural muscle capability.

Sarrazin, J. C.; Mascaro, Stephen A.

2014-03-01

406

Entropy production of a steady-growth cell with catalytic reactions  

E-print Network

Cells generally convert external nutrient resources to support metabolismand growth. Understanding the thermodynamic efficiency of this conversion is essential to determine the general characteristics of cellular growth. Using a simple protocell model with catalytic reaction dynamics to synthesize the necessary enzyme and membrane components from nutrients, the entropy production per unit cell-volume growth is calculated analytically and numerically based on the rate equation for chemical kinetics and linear non-equilibrium thermodynamics. The minimal entropy production per unit cell growth is found to be achieved at a non-zero nutrient uptake rate, rather than at a quasi-static limit as in the standard Carnot engine. This difference appears because the equilibration mediated by the enzyme exists only within cells that grow through enzyme and membrane synthesis. Optimal nutrient uptake is also confirmed by protocell models with many chemical components synthesized through a catalytic reaction network. The possible relevance of the identified optimal uptake to optimal yield for cellular growth is also discussed.

Yusuke Himeoka; Kunihiko Kaneko

2014-03-15

407

Money, taxes, and endogenous growth  

Microsoft Academic Search

This paper studies the positive and normative consequences of distortionary taxation in a monetary endogenous growth model with technological externalities. It is shown that the policy implications obtained from non-monetary growth models may significantly understate the actual effects. In addition, some policies that are optimal in non-monetary models may not be sustainable when money has a role in the economy.

R. Todd Smith

1996-01-01

408

USF Firsts, Facts, Honors, and Achievements,  

E-print Network

USF Firsts, Facts, Honors, and Achievements, 1855­2012 Alan Ziajka Associate Vice Provost, Facts, Honors, and Achievements.................................................................1 Jesuit........................................................................................................................................................................................................ 7 USF College of Arts and Sciences: Firsts, Facts, Honors, and Achievements

Galles, David

409

Protein metabolism in preterm infants with particular reference to intrauterine growth restriction  

PubMed Central

There is growing evidence that neonatal and long?term morbidity in preterm infants, particularly those born before 32?weeks' gestation, can be modified by attained growth rate in the neonatal period. Guidelines for optimal growth and the nutritional intakes, particular of protein, required to achieve this are not well defined. Due to delays in postnatal feeding and a lack of energy stores developed in the last trimester of pregnancy, preterm infants often suffer early postnatal catabolism until feeding is established. There are indications that infants born with intrauterine growth restriction have perturbations in protein metabolism. Therefore, they may have different protein requirements than appropriate for gestational age infants. This review summarises what is known about protein requirements and metabolism in the fetus and preterm infant, with particular emphasis on the distinct requirements of the growth?restricted infant. PMID:17585098

de Boo, H A; Harding, J E

2007-01-01

410

Achieving MAC layer fairness in wireless packet networks  

Microsoft Academic Search

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

Thyagarajan Nandagopal; Tae-Eun Kim; Xia Gao; Vaduvur Bharghavan

2000-01-01

411

Unsaturated fatty acids from food and in the growth medium improve growth of Bacillus cereus under cold and anaerobic conditions.  

PubMed

In a chemically defined medium and in Luria broth, cold strongly reduced maximal population density of Bacillus cereus ATCC 14579 in anaerobiosis and caused formation of filaments. In cooked spinach, maximal population density of B. cereus in anaerobiosis was the same at cold and optimal temperatures, with normal cell divisions. The lipid containing fraction of spinach, but not the hydrophilic fraction, restored growth of B. cereus under cold and anaerobiosis when added to the chemically defined medium. This fraction was rich in unsaturated, low melting point fatty acids. Addition of phosphatidylcholine containing unsaturated, low melting point, fatty acids similarly improved B. cereus anaerobic growth at cold temperature. Addition of hydrogenated phosphatidylcholine containing saturated, high melting point, fatty acids did not modify growth. Fatty acids from phospholipids, from spinach and from hydrogenated phosphatidylcholine, although normally very rare in B. cereus, were inserted in the bacterium membrane. Addition of phospholipids rich in unsaturated fatty acids to cold and anaerobic cultures, increased fluidity of B. cereus membrane lipids, to the same level as those from B. cereus normally cold adapted, i.e. grown aerobically at 15 °C. B. cereus is therefore able to use external fatty acids from foods or from the growth medium to adapt its membrane to cold temperature under anaerobiosis, and to recover the maximal population density achieved at optimal temperature. PMID:24010589

de Sarrau, Benoît; Clavel, Thierry; Zwickel, Nicolas; Despres, Jordane; Dupont, Sébastien; Beney, Laurent; Tourdot-Maréchal, Raphaëlle; Nguyen-The, Christophe

2013-12-01

412

Rapid optimization and prototyping for therapeutic antibody-like molecules  

PubMed Central

Multispecific antibody-like molecules have the potential to advance the standard-of-care in many human diseases. The design of therapeutic molecules in this class, however, has proven to be difficult and, despite significant successes in preclinical research, only one trivalent antibody, catumaxomab, has demonstrated clinical utility. The challenge originates from the complexity of the design space where multiple parameters such as affinity, avidity, effector functions, and pharmaceutical properties need to be engineered in concurrent fashion to achieve the desired therapeutic efficacy. Here, we present a rapid prototyping approach that allows us to successfully optimize these parameters within one campaign cycle that includes modular design, yeast display of structure focused antibody libraries and high throughput biophysical profiling. We delineate this approach by presenting a design case study of MM-141, a tetravalent bispecific antibody targeting two compensatory signaling growth factor receptors: insulin-like growth factor 1 receptor (IGF-1R) and v-erb-b2 erythroblastic leukemia viral oncogene homolog 3 (ErbB3). A MM-141 proof-of-concept (POC) parent molecule did not meet initial design criteria due to modest bioactivity and poor stability properties. Using a combination of yeast display, structured-guided antibody design and library-scale thermal challenge assay, we discovered a diverse set of stable and active anti-IGF-1R and anti-ErbB3 single-chain variable fragments (scFvs). These optimized modules were reformatted to create a diverse set of full-length tetravalent bispecific antibodies. These re-engineered molecules achieved complete blockade of growth factor induced pro-survival signaling, were stable in serum, and had adequate activity and pharmaceutical properties for clinical development. We believe this approach can be readily applied to the optimization of other classes of bispecific or even multispecific antibody-like molecules. PMID:23392215

Xu, Lihui; Kohli, Neeraj; Rennard, Rachel; Jiao, Yang; Razlog, Maja; Zhang, Kathy; Baum, Jason; Johnson, Bryan; Tang, Jian; Schoeberl, Birgit; Fitzgerald, Jonathan; Nielsen, Ulrik; Lugovskoy, Alexey A.

2013-01-01

413

Purine metabolite and energy charge analysis of Trypanosoma brucei cells in different growth phases using an optimized ion-pair RP-HPLC/UV for the quantification of adenine and guanine pools.  

PubMed

Human African Trypanosomiasis (HAT) is caused by the protozoan parasite Trypanosoma brucei. Although trypanosomes are well-studied model organisms, only little is known about their adenine and guanine nucleotide pools. Besides being building blocks of RNA and DNA, these nucleotides are also important modulators of diverse biochemical cellular processes. Adenine nucleotides also play an important role in the regulation of metabolic energy. The energetic state of cells is evaluated by the energy charge which gives information about how much energy is available in form of high energy phosphate bonds of adenine nucleotides. A sensitive and reproducible ion-pair RP-HPLC/UV method was developed and optimized, allowing the quantification of guanine and adenine nucleosides/nucleotides in T. brucei. With this method, the purine levels and their respective ratios were investigated in trypanosomes during logarithmic, stationary and senescent growth phases. Results of this study showed that all adenine and guanine purines under investigation were in the low mM range. The energy charge was found to decrease from logarithmic to static and to senescent phase whereas AMP/ATP, ADP/ATP and GDP/GTP ratios increased in the same order. In addition, the AMP/ATP ratio varied as the square of the ADP/ATP ratio, indicating AMP to be the key energy sensor molecule in trypanosomes. PMID:24657574

Graven, Patricia; Tambalo, Margherita; Scapozza, Leonardo; Perozzo, Remo

2014-06-01

414

Theoretical optimization of multi-layer InAs/GaAs quantum dots subject to post-growth thermal annealing for tailoring the photoluminescence emission beyond 1.3 ?m  

NASA Astrophysics Data System (ADS)

In this paper, we present theoretical analysis and computation for tuning the ground state (GS) photoluminescence (PL) emission of InAs/GaAs quantum dots (QDs) at telecommunication window of 1.3-1.55 ?m by optimizing its height and base dimensions through quantum mechanical concepts. For this purpose, numerical modelling is carried out to calculate the quantized energy states of finite dimensional QDs so as to obtain the GS PL emission at or beyond 1.3 ?m. Here, we also explored strain field altering the QD size distribution in multilayer heterostructure along with the changes in the PL spectra, simulation on post growth thermal annealing process which blueshifts the operating wavelength away from the vicinity of 1.3 ?m and improvement of optical properties by varying the thickness of GaAs spacing. The results are discussed in detail which will serve as an important information tool for device scientist fabricating high quality semiconductor quantum structures with reduced defects at telecommunication wavelengths.

Ghosh, K.; Naresh, Y.; Srichakradhar Reddy, N.

2012-07-01

415

Achieving the Benefits of Safeguards by Design  

SciTech Connect

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.

Trond Bjornard; Robert Bean; David Hebditch; Jim Morgan; Bruce Meppen; Scott DeMuth; Michael Ehinger; John Hockert

2008-07-01

416

Biodiesel surrogates: achieving performance demands.  

PubMed

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

Sarin, Rakesh; Kumar, Ravindra; Srivastav, Bhawana; Puri, S K; Tuli, D K; Malhotra, R K; Kumar, Anand

2009-06-01

417

Achieving a polio free world  

PubMed Central

Recently, the World Health Organization (WHO) declared that the spread of polio is an international public health emergency, and a coordinated international response is sought. Although the importance of such a response is recognized, there are challenges to stopping the spread of polio and achieving a polio free world. The most important issue is directing limited national resources to the specific areas where polio is endemic. In an article published in BMC Medicine, Upfill-Brown and his colleagues recognized this problem and successfully identified the potential risk areas in Nigeria using a validated spatial predictive model of wild poliovirus circulation. They also showed that a lower vaccine-derived population immunity is associated with the probability of a higher number of wild poliovirus cases within a district. Identification of the potential risk areas and understanding the magnitude of risk may help direct limited resources of the endemic countries to areas most at risk to maximize the impact of interventions and motivate the people to participate in the intervention program. These efforts are crucial if these endemic countries hope to eradicate polio. Please see related research article: http://www.biomedcentral.com/1741-7015/12/92.

2014-01-01

418

Extreme Vacua: Achievements and Expectations  

NASA Astrophysics Data System (ADS)

Obtaining pressures between 10-12 and 10-14 Torr inside vacuum systems operating at room temperature imposes severe limitations on the choice of materials and pumps. If the proper choice is made and the proper procedures are followed, the main obstacle to achieving such low pressure results from the hydrogen outgassing of the metal walls of the vacuum system. However, at the lower end of this range and for pumping systems based on getter pumps (both titanium sublimation and non-evaporable getter pumps), methane may become the main component of the residual gas pressure. Although a large effort has been devoted to developing suitable gauges, only a few of them have been actually tested at the extreme vacuum for which they were designed. Furthermore, none of the commercially available instruments is adequate for pressures below 10-12 Torr. The basic physical phenomena which contribute to defining the vacuum condition inside a system operating in this pressure range are reviewed. Guidelines to the selection of materials and pumps are given and discussed with the help of some examples.

Benvenuti, C.

1988-01-01

419

Academic Achievement Among Juvenile Detainees.  

PubMed

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

Grigorenko, Elena L; Macomber, Donna; Hart, Lesley; Naples, Adam; Chapman, John; Geib, Catherine F; Chart, Hilary; Tan, Mei; Wolhendler, Baruch; Wagner, Richard

2013-09-24

420

Closing the Achievement Gap: Challenges and Opportunities  

ERIC Educational Resources Information Center

Closing the achievement gap between low- and high-achieving public school students is an important goal of public education. This article explores background information and research and discusses examples of best practices to close the achievement gap. Several plans have been proposed as ways to enhance the achievement of under-represented…

Robards, Shirley N.

2008-01-01

421

Eyelid Growths  

MedlinePLUS

... Eye Disorders > Eyelid and Tearing Disorders 4 Eyelid Growths Noncancerous (benign) and cancerous (malignant) growths can form ... a microscope (biopsied) to exclude cancer. Other cancerous growths of the eyelids: Although less common, squamous cell ...

422

Growth Disorders  

MedlinePLUS

... because their parents are. But some children have growth disorders. Growth disorders are problems that prevent children from developing ... or other features. Very slow or very fast growth can sometimes signal a gland problem or disease. ...

423

Students' Motivational Profiles and Achievement 1 Running Head: STUDENTS' MOTIVATIONAL PROFILES AND ACHIEVEMENT  

E-print Network

Students' Motivational Profiles and Achievement 1 Running Head: STUDENTS' MOTIVATIONAL PROFILES AND ACHIEVEMENT Students' Motivational Profiles and Achievement Outcomes in Physical Education: A Self (2008) 688-701" #12;Students' Motivational Profiles and Achievement 2 Abstract Previous studies

Paris-Sud XI, Université de

424

Integrated multidisciplinary design optimization of rotorcraft  

NASA Technical Reports Server (NTRS)

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 paper describes the optimization formulation 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 aerodynamic performance optimization for minimum hover horsepower, rotor dynamic optimization for vibration reduction, rotor structural optimization for minimum weight, and integrated aerodynamic load/dynamics optimization for minimum vibration and weight.

Adelman, Howard M.; Mantay, Wayne R.

1989-01-01

425

Thermoacoustic Refrigerator's Stack Optimization  

NASA Astrophysics Data System (ADS)

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.

El-Fawal, Mawahib Hassan; Mohd-Ghazali, Normah; Yaacob, Mohd. Shafik; Darus, Amer Nordin

2010-06-01

426

Growth and study of nonlinear optical materials for frequency conversion devices with applications in defence and security  

NASA Astrophysics Data System (ADS)

A series of nonlinear materials including GaAs, GaP, and ZnSe have been examined to determine their suitability for non-linear frequency conversion devices (FCD) and more specifically their use as high power, compact and broadly tunable IR and THz sources for defense and security applications. The more mature GaAs was investigated to reveal the causes for the optical losses that restrict achievement of higher conversion efficiency in quasi-phasematched FCD, while the efforts with GaP were oriented in developing simple, cost effective techniques for fabrication of orientation patterned (OP) templates and optimizing the subsequent thick HVPE growth on these templates. Thus, average growth rates of 50- 70 ?m/h were achieved in up to 8-hour long experiments. High optical layer quality was achieved by suitable control of the process parameters. The optimal orientation of the pattern was determined and used as essential feedback aiming to improve the template preparation. This led to the production of the first 300-400 ?m thick device quality OPGaP. Efforts to suppress the parasitic nucleation during growths with longer duration or to achieve thicker layers by a 2 step growth process were also made. The main challenge with the newer candidate, OPZnSe, was to establish suitable regimes for hydrothermal growth on plain (001) ZnSe seeds grown by chemical vapor deposition. Two different temperature ranges, 330-350 °C and 290-330 °C, were investigated. The mineralized concentration was also manipulated to accelerate the growth in (111) direction and, thus, to improve the growth in (001) direction. The next material in the line is GaN. The traditional HVPE approach will be combined with a growth at low reactor pressure. Growths will be performed in the next sequence: growth on thin GaN layers grown by MOCVD on sapphire wafers, growth on half-patterned GaN templates with different orientations and, finally, growth on OPGaN templates.

Tassev, V.; Snure, M.; Vangala, S.; Kimani, M.; Peterson, R.; Schunemann, P.

2014-10-01

427

Search Engine Optimization 1  

E-print Network

Search Engine Optimization (SEO) is an Internet marketing strategy and a process, widely used now-a-days for improving the volume or quality of traffic to a website through search engines. The results generated by search engines can be natural (organic or algorithmic) and/or paid search. In the present study, different techniques were used for achieving better optimization for Web 2.0 based websites. Different techniques related to SEO like keyword discovery, crawling, on-page and off-page optimization and different Google tools are discussed in this paper. The present study also study also describes the impact of SEO on Internet marketing. The results of the investigation help webmasters to gain a deep insight about SEO and also to guide them in making better decisions regarding their online advertising and marketing campaign.

Karthikeyan K; Sangeetha M

428

Isoflavone Augmentation in Soybean Cell Cultures Is Optimized Using Response Surface Methodology.  

PubMed

Glycine max contains potential therapeutic isoflavones, and its productivity in plants is considerably influenced worldwide by several biotic and abiotic factors. Optimization of soybean cell suspension cultures (Indian variety, JS 335) to maximize the cell growth and isoflavone production in the present study was performed using response surface methodology (RSM) with three independent variables of plant growth regulators, 2,4-dichlorophenoxyacetic acid (2,4-D), 1-naphthalene acetic acid (?-NAA), and kinetin (Kn). The maximum biomass achieved was 70.62 g/L dry weight (dw) using the optimized medium of 2.10 mg/L 2,4-D, 5.52 mg/L ?-NAA, and 0.35 mg/L Kn supplemented in the Murashige and Skoog (MS) basal medium. The total isoflavone content of 38.59 mg/g of dw was obtained in the medium with optimized conditions of 1.33 mg/L 2,4-D, 1.76 mg/L ?-NAA, and 0.15 mg/L Kn. In comparison to field-grown soybean seeds, the cell suspension cultures profoundly augmented isoflavone concentrations. The optimized conditions for both biomass and total isoflavone content were evaluated by superimposing the contour plots. The results suggested that the optimized medium of cell suspension cultures possibly be used for scale-up studies in bioreactors to offer a high content of bioactive isoflavones. PMID:24678665

Akitha Devi, M K; Giridhar, P

2014-03-31

429

Optimal quantum cloning via spin networks  

SciTech Connect

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.

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

430

Adaptive Growth Decisions in Butterflies  

NSDL National Science Digital Library

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.

Karl Gotthard (Stockholm University; )

2008-03-01

431

Crystal Growth Control  

NASA Technical Reports Server (NTRS)

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.

Duval, Walter M. B.; Batur, Celal; Bennett, Robert J.

1997-01-01

432

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

ERIC Educational Resources Information Center

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

Edwards, Anthony C.

2012-01-01

433

The Relationship among Achievement Motivation Orientations, Achievement Goals, and Academic Achievement and Interest: A Multiple Mediation Analysis  

ERIC Educational Resources Information Center

The aim of the present study is to examine the relationships among achievement motivation orientations and academic achievement and interest and whether achievement goals mediate these relationships. A sample of 503 students aged 14-16 years from 8 secondary schools in two Australia cities responded to a questionnaire package, comprising measures…

Abd-El-Fattah, Sabry M.; Patrick, Rosan R.

2011-01-01

434

Optimal Implementation of Intervention Strategies for Elderly People with Ludomania  

PubMed Central

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

Kim, Byul Nim; Masud, M.A.; Kim, Yongkuk

2014-01-01

435

Variability-Aware Optimization of Nano-CMOS Active Pixel Sensors  

E-print Network

is optimized using a design and analysis of Monte Carlo experiments based optimization. We achieve 21 using Design and Analysis of Monte Carlo Experiments Dhruva Ghai , Saraju P. Mohanty and Elias Kougianos is optimized using a design and analysis of Monte Carlo experiments based optimization. · We achieve 21

Mohanty, Saraju P.

436

Achieving Maximal Speed of Solution Exchange for Patch Clamp Experiments  

PubMed Central

Background Resolving the kinetics of agonist binding events separately from the subsequent channel gating processes requires the ability of applying and removing the agonist before channel gating occurs. No reported system has yet achieved pulses shorter than 100 µs, necessary to study nicotinic ACh receptor or AMPA receptor activation. Methodology/Principal Findings Solution exchange systems deliver short agonist pulses by moving a sharp interface between a control and an experimental solution across a channel preparation. We achieved shorter pulses by means of an exchange system that combines a faster flow velocity, narrower partition between the two streams, and increased velocity and bandwidth of the movement of the interface. The measured response of the entire system was fed back to optimize the voltage signal applied to the piezoelectric actuator overcoming the spurious oscillations arising from the mechanical resonances when a high bandwidth driving function was applied. Optimization was accomplished by analyzing the transfer function of the solution exchange system. When driven by optimized command pulses the enhanced system provided pulses lasting 26 ± 1 µs and exchanging 93 ± 1% of the solution, as measured in the open tip of a patch pipette. Conclusions/Significance Pulses of this duration open the experimental study of the molecular events that occur between the agonist binding and the opening of the channel. PMID:22879927

Auzmendi, Jerónimo; Fernández Do Porto, Darío; Pallavicini, Carla; Moffatt, Luciano

2012-01-01

437

Improving Education Achievement and Attainment in Luxembourg. OECD Economics Department Working Papers, No. 508  

ERIC Educational Resources Information Center

Improving education achievement in Luxembourg is a priority for strengthening productivity growth and enhancing residents' employment prospects in the private sector, where employers mainly hire cross-border workers. Student achievement in Luxembourg is below the OECD average according to the 2003 OECD PISA study, with the performance gap between…

Carey, David; Ernst, Ekkehard

2006-01-01

438

Academic Achievement Trajectories of Adolescents from Mexican and East Asian Immigrant Families in the United States  

ERIC Educational Resources Information Center

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…

Jeong, Yu-Jin; Acock, Alan C.

2014-01-01

439

Changes in Self-Esteem across the First Year in College: The Role of Achievement Goals  

ERIC Educational Resources Information Center

This longitudinal study examined the effects of achievement goals on the growth trajectories of self-esteem during the first-year at a comprehensive public university. College freshmen (N = 311) were followed for one academic year with three time points. Between-individual differences and within-individual change in achievement goals were…

Shim, Sungok Serena; Ryan, Allison M.; Cassady, Jerrell

2012-01-01

440

Health Risk Behaviors and Academic Achievement  

MedlinePLUS

... and Academic Achievement What is the relationship between health-risk behaviors and academic achievement? Data presented below from ... Percentage of high school students who engaged in health-risk behaviors, by type of grades earned (mostly A’s, ...

441

Academic Achievement And Work In West  

E-print Network

Academic Achievement And Work In West Virginia 2007 Results By ACT Score And College Grade Point.......................................................................................................15 #12;#12;Academic Achievement And Work In West Virginia 2007 1 Executive Summary Public

Mohaghegh, Shahab

442

Multivariate Prediction of Early School Achievement.  

ERIC Educational Resources Information Center

While many studies have predicted elementary school achievement, few have investigated both cognitive and biographical predictors simultaneously in a multiple regression format. The present study used both types of variables in predicting achievement over a 20 month span. Criterion variables consisted of Stanford Achievement Test subscores, and a…

Shack, David M.; Owen, Steven V.

443

Instrument Achievement Goal for Chinese Students  

Microsoft Academic Search

What kind of achievement goals do Chinese students choose and pursue? The current study demonstrated a culture-specific achievement goal, i.e., instrument goal, and investigated its relationship with learning strategy and academic achievement. 536 students from a middle school in northeast China participated in the current investigation. The findings provided a further support that instrument goal could be seen as a

Chang-Jiang Liu; Xiao-Ping Sun; Li-Yan Guo; Bao-Cai Han

2008-01-01

444

Age and Achievement: A Dissenting View.  

ERIC Educational Resources Information Center

A study of intellectual and creative achievers in two periods of significant intellectual and creative achievement, 18th century Scotland and 15th century Florence, found that one of the most significant variables was longevity. Achievement was more or less continuous over the whole life span. (Author)

Bullough, Vern; And Others

1978-01-01

445

School District Organization and Student Achievement  

ERIC Educational Resources Information Center

Study examines determinants of organizational effectiveness. Results indicate that pupil-teacher ratio and administrative intensity depress median levels of achievement; whereas, staff qualifications foster student achievement. The percentage of non-whites is said to have a consistently significant direct effect on median achievement level.…

Bidwell, Charles E.; Kasarda, John D.

1975-01-01

446

Avoidance achievement motivation: A personal goals analysis  

Microsoft Academic Search

The present research investigated one antecedent and various consequences of pursuing avoidance personal achievement goals over the course of a semester. The authors assessed participants' achieve- ment-relevant goals using the newly devised Achievement Goals Questionnaire. The motive to avoid failure, assessed with self-report and projective measures, was established as an antecedent of avoid- ance goal pursuit. Avoidance regulation was shown

Andrew J. Elliot; Kennon M. Sheldon

1997-01-01

447

Assessment of Achievement Motives: Comments and Suggestions  

Microsoft Academic Search

Nygård, R. & Gjesme, T. 1973. Assessment of Achievement Motives: Comments and Suggestions. Scand. J. educ. Res. 17, 39?46. Measuring instruments usually employed in achievement motivation research are reviewed and appraised. The following conclusions are drawn; (a) the validity of the need for achievement tests, especially when used among females, is questionable; (b) the objective tests assumed to indicate the

Roald Nygård; Torgrim Gjesme

1973-01-01

448

Fantasy need achievement as a motivational construct  

Microsoft Academic Search

The McClelland-Atkinson theory that arousal of achievement fantasy depends upon arousal of the achievement motive is examined critically in light of accrued empirical evidence. The effects of achievement-arousal conditions on fantasy n Ach are shown to be probably nonmotivational. n Ach scores are shown to be correlated with performance measures in about ½ of the studies reported, but the pattern

Eric Klinger

1966-01-01

449

The Intersection of Culture and Achievement Motivation  

ERIC Educational Resources Information Center

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…

Trumbull, Elise; Rothstein-Fisch, Carrie

2011-01-01

450

Achievement Goals of Students with ADHD  

ERIC Educational Resources Information Center

Although achievement goal theory is currently one of the dominant theoretical frameworks used to understand and improve student motivation (Brophy, 2004), little work has been done to evaluate the achievement goals of students with ADHD. After an initial review of achievement goal theory, the current study begins to address four research…

Barron, Kenneth E.; Evans, Steven W.; Baranik, Lisa E.; Serpell, Zewelanji N.; Buvinger, Elizabeth

2006-01-01

451

Examining the Stability of Achievement Goal Orientation  

ERIC Educational Resources Information Center

We examined stability and change in students' achievement goal orientations over varying tasks. Two naturalistic longitudinal studies were conducted in undergraduate courses. Students completed self-reports designed to measure their achievement goals. Achievement goals were measured four times: prior to two assignments and two exams. Four…

Muis, Krista R.; Edwards, Ordene

2009-01-01

452

Subgroup Achievement and Gap Trends: Vermont, 2010  

ERIC Educational Resources Information Center

This paper profiles the student subgroup achievement and gap trends in Vermont for 2010. Vermont's demographic profile is such that achievement trends could only be determined for white, male and female, and low-income student subgroups. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), the white, low-income,…

Center on Education Policy, 2010

2010-01-01

453

Subgroup Achievement and Gap Trends: Oklahoma, 2010  

ERIC Educational Resources Information Center

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…

Center on Education Policy, 2010

2010-01-01

454

The Influence of Poverty on Achievement  

ERIC Educational Resources Information Center

Without a doubt, poverty has a negative influence on student achievement, especially when achievement is measured by state-mandated standardized tests. However, some bureaucrats, such as state commissioners of education and even state governors, continue to downplay the influence of poverty on student achievement. New Jersey's Governor Chris…

Tienken, Christopher H.

2012-01-01

455

Student Achievement: A Factor in Classroom Dynamics?  

ERIC Educational Resources Information Center

Differences in interaction patterns between teachers and high/low achieving and high/low expectation students were examined in four grade 3 and six grade 6 classes, involving 237 students. Teachers interacted most frequently with high achieving/expectancy students, but spent more time waiting for and interacting with low achieving/expectancy…

Leder, Gilah C.

1987-01-01

456

Examination of growth rate during hydride vapor phase epitaxy of GaN on ammonothermal GaN seeds  

NASA Astrophysics Data System (ADS)

One of the main advantages of the hydride vapor phase epitaxy (HVPE) method for crystallizing bulk gallium nitride is the crystallization of GaN with a relatively high growth rate (>100 ?m/h). In this paper various growth rates in the c-direction during crystallization of GaN by HVPE on ammonothermally grown GaN crystals are determined and examined. The influence of the highest (380 ?m/h) and the lowest (40 ?m/h) growth rate on the structural quality and purity of the HVPE-GaN crystals is analyzed. The optimal macroscopically stable growth rate (without cracks and pits) and the way of achieving it are presented and discussed.

Sochacki, T.; Amilusik, M.; Fijalkowski, M.; Lucznik, B.; Weyher, J. L.; Grzegory, I.; Kucharski, R.; Iwinska, M.; Bockowski, M.

2014-12-01

457

Development of the vertical Bridgman technique for 6-inch diameter c-axis sapphire growth supported by numerical simulation  

NASA Astrophysics Data System (ADS)

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.

Miyagawa, Chihiro; Kobayashi, Takumi; Taishi, Toshinori; Hoshikawa, Keigo

2014-09-01

458

Enriching the Hierarchical Model of Achievement Motivation: Autonomous and Controlling Reasons Underlying Achievement Goals  

ERIC Educational Resources Information Center

Background: The hierarchical model of achievement motivation presumes that achievement goals channel the achievement motives of need for achievement and fear of failure towards motivational outcomes. Yet, less is known whether autonomous and controlling reasons underlying the pursuit of achievement goals can serve as additional pathways between…

Michou, Aikaterini; Vansteenkiste, Maarten; Mouratidis, Athanasios; Lens, Willy

2014-01-01

459

Effect of calcium, phosphate and nitrogen on cell growth and biosynthesis of cell wall polysaccharides by Silene vulgaris cell culture.  

PubMed

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

Günter, Elena A; Ovodov, Yury S

2005-06-29

460

Recombinant collagen production optimization in Escherichia coli  

E-print Network

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 ...

Whittemore, Brett A

2005-01-01

461

Wastewater treatment benchmark: what can be achieved with simple control?  

PubMed

In this paper a simple control strategy is applied to and assessed on the wastewater treatment benchmark. The controllers used in the presented control strategy are PI controllers, feedforward control and a step-feed procedure. The controlled variables are not directly the effluent concentrations but other process variables which have an effect on the effluent. The setting of set-points is also analyzed to select the values with the best performance. Set-point analysis has shown that with an optimal setting of set-points under stormy influent conditions, the achieved plant performance is also retained for rainy and dry influent conditions. The evaluation of plant performance indicates that with the proposed control strategy, a lower number of effluent violations has been achieved, as well as lower energy consumption and lower sludge production, when compared to results published up to now. Only the effluent quality criterion deteriorated. PMID:11936625

Vrecko, D; Hvala, N; Kocijan, J

2002-01-01

462

Autocrine Hepatocyte Growth Factor Provides a Local Mechanism for Promoting Axonal Growth  

Microsoft Academic Search

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