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1

Achieving optimal growth: lessons from simple metabolic modules  

NASA Astrophysics Data System (ADS)

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

Goyal, Sidhartha; Chen, Thomas; Wingreen, Ned

2009-03-01

2

Optimism versus Pessimism and Academic Achievement Evaluation  

ERIC Educational Resources Information Center

|This article integrates three central theories of optimism-pessimism (OP). The combination of the shared components of these theories--outcome expectancies, emotions, and behavioral intention--may produce an integrative academic achievement evaluation. Little has been written regarding the differentiation between general and domain-specific OP, a…

Harpaz-Itay, Yifat; Kaniel, Shlomo

2012-01-01

3

Achieving Egyptian Export Growth. Final Report.  

National Technical Information Service (NTIS)

This study assesses Egypt's prospects for export growth, sets forth an 'export vision' in which Egypt will double its nontraditional merchandise exports in 4 years and triple them in 6, and proposes a strategy for achieving this vision. Introductory secti...

1995-01-01

4

Student Achievement and National Economic Growth  

ERIC Educational Resources Information Center

Educational policy around the world has increasingly focused on improving aggregate student achievement as a means to increase economic growth. In the last two decades, attention has focused especially on the importance of achievement in science and mathematics. Yet, the policy commitments involved have not been based on research evidence. The…

Ramirez, Francisco O.; Luo, Xiaowei; Schofer, Evan; Meyer, John W.

2006-01-01

5

Achievement Growth in Public and Catholic Schools.  

ERIC Educational Resources Information Center

|Catholic schools have a positive effect on verbal and mathematics achievement growth from the sophomore to senior year of high school. Catholic schools produce higher-achieving students in academic programs, require more semesters of academic coursework, and assign more homework. (Author/RM)|

Hoffer, Thomas; And Others

1985-01-01

6

Optimization of microorganisms growth processes.  

PubMed

Microorganisms growth processes are encountered in many biotechnological applications. For an increased economic benefit, optimizing their productivity is of great interest. Often the growth is inhibited by the presence in excess of other components. Inhibition determines the occurrence of multiple equilibrium points, which makes the optimal steady state reachable only from a small region of the system state space. Thus dynamic control is needed to drive the system from an initial state (characterized by a low concentration of microorganisms) to the optimal steady state. The strategy presented in this paper relies on the solutions of two optimization problems: the problem of optimal operation for maximum productivity in steady state (steady state optimization) and the problem of the start-up to the optimal steady state (transient optimization). Steady state optimization means determining the optimal equilibrium point (the amount of microorganisms harvested is maximum). The transient optimization is solved using the maximum principle of Pontryagin. The proposed control law, which drives the bioreactor from an initial state to the optimal steady state while maximizing the productivity, consists of switching the manipulated variable (dilution rate) from the minimum to the maximum value and then to the optimal value at well defined instants. This control law substantially increases the stability region of the optimal equilibrium point. Aside its efficiency, the strategy is also characterized by simplicity, being thus appropriate for implementation in real-life systems. Another important advantage is its generality: this technique may be applied to any microorganisms growth process which involves only one biochemical reaction. This means that the sequence of the control levels does not depend on the structure and parameters of the reaction kinetics, the values of the yield coefficients or the number of components in the bioreactor. PMID:20615574

Sbarciog, M; Loccufier, M; Noldus, E

2010-07-07

7

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

8

Knowledge Network Model of Scientific Research Achievement and its Optimization  

Microsoft Academic Search

In order to promote knowledge sharing and knowledge reuse of scientific research achievements, this paper proposes a knowledge network model which acts as a direct access to the knowledge existed in the achievements. As knowledge network can be treated with a kind of complex networks, this paper then optimizes the primitive knowledge network model by analyzing its network characteristics. Figures

Yang Yu; Yanzhong Dang

2008-01-01

9

Optimal conclusive discrimination of two states can be achieved locally  

SciTech Connect

This paper constructs a local operation and classical communication protocol that achieves the global optimality of conclusive discrimination of any two pure states with arbitrary a priori probability. This can be interpreted that there is no 'nonlocality' in the conclusive discrimination of two multipartite pure states.

Ji Zhengfeng; Cao Hongen; Ying Mingsheng [State Key Laboratory of Intelligent Technology and Systems, Department of Computer Science and Technology, Tsinghua University, Beijing 100084 (China)

2005-03-01

10

Academic optimism and student achievement in urban elementary schools  

Microsoft Academic Search

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 and multiple regression and factor analyses were used

Page A. Smith; Wayne K. Hoy

2007-01-01

11

Reading Achievement Growth in Children with Language Impairments  

ERIC Educational Resources Information Center

|Purpose: This study examined the reading achievement growth of children with language impairments (LI) across the school grades. The authors sought to determine whether children with LI demonstrate a delayed, deficit, or cumulative pattern of reading achievement growth when compared with children with typical language (TL). Method: A group of 225…

Catts, Hugh W.; Bridges, Mindy Sittner; Little, Todd D.; Tomblin, J. Bruce

2008-01-01

12

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

13

Optimal growth models as Economic Planning Tools  

Microsoft Academic Search

In the present paper, I have carried out an investigation into the form of models which would be suitable for economy-wide planning. Optimal growth models have usually been constructed in an abstract framework. Therefore, the economies for which optimal growth models would be suitable are not identified. I have shown that, because these models only embody purely physical constraints, they

Peter Murrell

1980-01-01

14

Optimal age of retirement and population growth  

Microsoft Academic Search

.   The purpose of this paper is to study intergenerational optimal resources sharing when the social planer can choose the retirement\\u000a age in addition to consumptions and investment. We use the extension of the Diamond analysis by Hu [1979] that incorporates\\u000a endogenous retirement age. We found that the optimal retirement age is an increasing function of the population growth rate

Bertrand Crettez; Patricia Le Maitre

2002-01-01

15

Optimal growth strategies under divergent predation pressure.  

PubMed

The conditions leading to gigantism in nine-spined sticklebacks Pungitius pungitius were analysed by modelling fish growth with the von Bertalanffy model searching for the optimal strategy when the model's growth constant and asymptotic fish size parameters are negatively related to each other. Predator-related mortality was modelled through the increased risk of death during active foraging. The model was parameterized with empirical growth data of fish from four different populations and analysed for optimal growth strategy at different mortality levels. The growth constant and asymptotic fish size were negatively related in most populations. Optimal fish size, fitness and life span decreased with predator-induced mortality. At low mortality, the fitness of pond populations was higher than that of sea populations. The differences disappeared at intermediate mortalities, and sea populations had slightly higher fitness at extremely high mortalities. In the scenario where all populations mature at the same age, the pond populations perform better at low mortalities and the sea populations at high mortalities. It is concluded that a trade-off between growth constant and asymptotic fish size, together with different mortality rates, can explain a significant proportion of body size differentiation between populations. In the present case, it is a sufficient explanation of gigantism in pond P. pungitius. PMID:23331153

Aikio, S; Herczeg, G; Kuparinen, A; Merilä, J

2012-12-17

16

Multidisciplinary optimization for engineering systems - Achievements and potential  

NASA Astrophysics Data System (ADS)

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

17

Multidisciplinary optimization for engineering systems: Achievements and potential  

NASA Astrophysics Data System (ADS)

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

1989-03-01

18

Oystercatchers use colour preference to achieve longer-term optimality.  

PubMed Central

The optimal diet model entails that foragers look beyond the individual prey encounter, to at least the level of intake rate across a bout of foraging, but optimization over a longer time remains controversial. In this paper, we show how oystercatchers increase their intake over the longer term using mussel colour as a cue. Wintering oystercatchers Haematopus ostralegus feed extensively on mussels Mytilus edulis in the estuaries of southern Britain. They show a marked preference for brown-shelled mussels over the commoner black-shelled morph, and we show that this enables them to maximize their rate of energy gain over a longer period than a single foraging bout. The brown and black mussels did not differ in ventral thickness and energy content, which are the main criteria for mussel selection and most important for short-term optimization. The brown mussels contained significantly less moisture, so by selecting them, oystercatchers could pack more mussel flesh into their limited oesophageal storage capacity. This enables them to increase their overall consumption during a feeding bout and increases their long-run energy gain rate, to an extent that is large enough to be significant for survival, especially during the short exposure of the mussel beds in winter.

Nagarajan, R; Goss-Custard, J D; Lea, S E G

2002-01-01

19

Optimal Growth with Robust Feedback Control.  

National Technical Information Service (NTIS)

Optimal control theory is no less important in economics today than welfare economics was twenty years ago. It is used to evaluate different growth paths; and it forms a crucial part of the long-run theory of the firm. It has been used to derive an aggreg...

E. F. Infante J. L. Stein

1972-01-01

20

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

21

Achieving the “Low Carbon, Green Growth” Vision in Korea  

Microsoft Academic Search

Korea, which has had the highest growth rate of greenhouse gas emissions in the OECD area since 1990, adopted an ambitious Green Growth Strategy in 2009. It aims at reducing emissions by 30% by 2020 relative to a “business as usual” scenario, implying a 4% cut from the 2005 level. The Strategy also includes a Five-Year Plan with public spending

Randall S. Jones; Byungseo Yoo

2012-01-01

22

The maximally achievable accuracy of linear optimal regulators and linear optimal filters  

Microsoft Academic Search

A linear system with a quadratic cost function, which is a weighted sum of the integral square regulation error and the integral square input, is considered. What happens to the integral square regulation error as the relative weight of the integral square input reduces to zero is investigated. In other words, what is the maximum accuracy one can achieve when

Huibert Kwakernaak; Raphael Sivan

1972-01-01

23

Growth optimal investment in horse race markets with costs  

Microsoft Academic Search

We formulate the problem of growth optimal investment in horse race markets with proportional costs and study growth optimal strategies both for stochastic horse races as well as races where one does not make any distributional assumptions. Our results extend all known results for frictionless horse race markets to their natural analog in markets with costs

Garud N. Iyengar; Thomas M. Cover

2000-01-01

24

Lattice Coding and Decoding Achieve the Optimal Diversity-Multiplexing Tradeoff of MIMO Channels  

Microsoft Academic Search

This paper considers communication over coherent multiple-input multiple-output (MIMO) flat fading channels where the channel is only known at the receiver. For this setting, we in- troduce the class of LAttice Space-Time (LAST) codes. We show that these codes achieve the optimal diversity-vs-multiplexing tradeoff defined by Zheng and Tse under generalized minimum Euclidean distance lattice decoding. Our scheme is based

Hesham El Gamal; Giuseppe Caire; Mohamed Oussama Damen

2004-01-01

25

Developing Countries: Achieving Poor Countries' Economic Growth and Debt Relief Targets Faces Significant Financing Challenges.  

National Technical Information Service (NTIS)

The Heavily Indebted Poor Countries (HIPC) Initiative, established in 1996, is a bilateral and multilateral effort to provide debt relief to poor countries to help them achieve economic growth and debt sustainability. Multilateral creditors are having dif...

2004-01-01

26

Optimization of the cooling profile to achieve crack-free Yb:S-FAP crystals  

SciTech Connect

Yb:S-FAP [Yb{sup 3+}:Sr{sub 5}(PO{sub 4}){sub 3}F] crystals are an important gain medium for diode-pumped laser applications. Growth of 7.0 cm diameter Yb:S-FAP crystals utilizing the Czochralski (CZ) method from SrF{sub 2}-rich melts often encounter cracks during the post growth cool down stage. To suppress cracking during cool down, a numerical simulation of the growth system was used to understand the correlation between the furnace power during cool down and the radial temperature differences within the crystal. The critical radial temperature difference, above which the crystal cracks, has been determined by benchmarking the simulation results against experimental observations. Based on this comparison, an optimal three-stage ramp-down profile was implemented and produced high quality, crack-free Yb:S-FAP crystals.

Fang, H; Qiu, S; Kheng, L; Schaffers, K; Tassano, J; Caird, J; Zhang, H

2007-08-20

27

Modeling Stability of Growth between Mathematics and Science Achievement During Middle and High School  

Microsoft Academic Search

In this study, the authors introduced a multivariate multilevel model to estimate the consistency among students and schools in the rates of growth between mathematics and science achievement during the entire middle and high school years with data from the Longitudinal Study of American Youth (LSAY). There was no evident consistency in the rates of growth between mathematics and science

Xin Ma; Lingling Ma

2004-01-01

28

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

29

Non-optimal codon usage is a mechanism to achieve circadian clock conditionality  

PubMed Central

Circadian rhythms are oscillations in biological processes that function as a key adaptation to the daily rhythms of most environments. In the model cyanobacterial circadian clock system, the core oscillator proteins are encoded by the gene cluster kaiABC1. Genes with high expression and functional importance like the kai genes are usually encoded by optimal codons, yet the codon usage bias of the kaiBC genes is not optimized for translational efficiency. We discovered a relationship between codon usage and a general property of circadian rhythms called conditionality; namely, that endogenous rhythmicity is robustly expressed under some environmental conditions but not under others2. Despite the generality of circadian conditionality, however, its molecular basis is unknown for any system. Here we show that non-optimal codon usage was selected as a post-transcriptional mechanism to switch between circadian and non-circadian regulation of gene expression as an adaptive response to environmental conditions. When the kaiBC sequence was experimentally optimized to enhance expression of the KaiB and KaiC proteins, intrinsic rhythmicity was enhanced at cool temperatures that are experienced by this organism in its natural habitat. However, fitness at those temperatures was highest in cells whose endogenous rhythms were suppressed at cool temperatures as compared with cells exhibiting high-amplitude rhythmicity. These results indicate natural selection against circadian systems in cyanobacteria that are intrinsically robust at cool temperatures. Modulation of circadian amplitude is therefore critical to its adaptive significance3. Moreover, these results show the direct effects of codon usage on a complex phenotype and organismal fitness. Our work also challenges the long-standing view of directional selection towards optimal codons4–7, and provides a key example of natural selection against optimal codon to achieve adaptive responses to environmental changes.

Xu, Yao; Ma, Peijun; Shah, Premal; Rokas, Antonis; Liu, Yi; Johnson, Carl Hirschie

2013-01-01

30

Bayesian D-optimal designs for the exponential growth model  

Microsoft Academic Search

Bayesian optimal designs for nonlinear regression models are of some interest and importance in the statistical literature. Numerical methods for their construction are well-established, but very few analytical studies have been reported. In this paper, we consider an exponential growth model used extensively in the modelling of simple organisms, and examine the explicit form of the Bayesian D-optimal designs. In

Saurabh Mukhopadhyay; Linda M. Haines

1995-01-01

31

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...

32

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

33

Flux Consumption Optimization and the Achievement of 1MA Discharge on NSTX  

SciTech Connect

The spherical tokamak (ST), because of its slender central column, has very limited volt-second capability relative to a standard aspect ratio tokamak of similar plasma cross-section. Recent experiments on the National Spherical Torus Experiment (NSTX) have begun to quantify and optimize the ohmic current drive efficiency in a MA-class ST device. Sustainable ramp-rates in excess of 5MA/sec during the current rise phase have been achieved on NSTX, while faster ramps generate significant MHD activity. Discharges with IP exceeding 1MA have been achieved in NSTX with nominal parameters: aspect ratio A=1.3-1.4, elongation k=2-2.2, triangularity d=0.4, internal inductance li=0.6, and Ejima coefficient CE =0.35. Flux consumption efficiency results, performance improvements associated with first boronization, and comparisons to neo-classical resistivity are described.

J. Menard; B. LeBlanc; S.A. Sabbagh; M. Bell; R. Bell; et al

2000-11-16

34

Optimal Growth with Robust Feedback Control.  

National Technical Information Service (NTIS)

The paper is divided into four parts. A brief discussion of the Pontraygin's Maximum Principle is contained in Part 1. A mathematical derivation of the Feedback Control law is the subject of Part 2. The optimal and suboptimal nature of the FC law is discu...

E. Infante J. L. Stein

1970-01-01

35

Reactor and growth process optimization for growth of thick GaN layers on sapphire substrates by HVPE  

Microsoft Academic Search

In total, 120?m thick GaN layers without cracks have been grown on 2in sapphire substrates by hydride vapor phase epitaxy. This has been achieved by optimization of the flow patterns in the reactor based on 3D process modelling, choice of the growth parameters especially the carrier gas composition and the usage of suitable GaN\\/sapphire templates. An important finding is that

E. Richter; Ch. Hennig; M. Weyers; F. Habel; J.-D. Tsay; W.-Y. Liu; P. Brückner; F. Scholz; Yu. Makarov; A. Segal; J. Kaeppeler

2005-01-01

36

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

Microsoft Academic Search

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 modeling (GCM). This study introduces a cross-classified multiple membership growth curve model (CCMM-GCM)

Matthew W. Grady; S. Natasha Beretvas

2010-01-01

37

Growth in Reading Achievement of Students with Disabilities, Ages 7 to 17  

ERIC Educational Resources Information Center

Using data from the Special Education Elementary Longitudinal Study (SRI International, 2002), this study estimated reading growth trajectories in a nationally representative sample of 3,421 students with disabilities ages 7 to 17 representing 11 federal disability categories. Reading achievement in all disability categories increased with age,…

Wei, Xin; Blackorby, Jose; Schiller, Ellen

2011-01-01

38

Growth in Reading Achievement of Students with Disabilities, Ages 7 to 17  

ERIC Educational Resources Information Center

|Using data from the Special Education Elementary Longitudinal Study (SRI International, 2002), this study estimated reading growth trajectories in a nationally representative sample of 3,421 students with disabilities ages 7 to 17 representing 11 federal disability categories. Reading achievement in all disability categories increased with age,…

Wei, Xin; Blackorby, Jose; Schiller, Ellen

2011-01-01

39

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

40

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

41

Growth without pain: the world can achieve sustained economic growth by reducing waste  

Microsoft Academic Search

The case is presented for eliminating America's wasteful methods of manufacturing, distributing, and consuming goods as a prerequisite for continuing world economic growth. While waste is difficult to define, there is a growing awareness that it is costly and that some external discipline is required to effect a change in lifestyles. A cost\\/benefit analysis of waste management would indicate the

van Dam

1978-01-01

42

Transaction fees and optimal rebalancing in the growth-optimal portfolio  

NASA Astrophysics Data System (ADS)

The growth-optimal portfolio optimization strategy pioneered by Kelly is based on constant portfolio rebalancing which makes it sensitive to transaction fees. We examine the effect of fees on an example of a risky asset with a binary return distribution and show that the fees may give rise to an optimal period of portfolio rebalancing. The optimal period is found analytically in the case of lognormal returns. This result is consequently generalized and numerically verified for broad return distributions and returns generated by a GARCH process. Finally we study the case when investment is rebalanced only partially and show that this strategy can improve the investment long-term growth rate more than optimization of the rebalancing period.

Feng, Yu; Medo, Matúš; Zhang, Liang; Zhang, Yi-Cheng

2011-05-01

43

DIGITAL DIVIDES AND CAPITAL CONVERSION: The optimal use of information and communication technology for youth reading achievement  

Microsoft Academic Search

Analysis of a nationally representative survey of 15-year-old Canadian youth indicates how capital can be converted from one form to another by examining the use of information and communication technology (ICT) and reading achievements. Overall there is a negligible linear relationship but a pronounced curvilinear one between these variables, suggesting an optimal level of ICT use. This optimal point varies

Victor Thiessen; E. Dianne Looker

2007-01-01

44

Optimization of nutritional requirements for mycelial growth and sporulation of entomogenous fungus Aschersonia aleyrodis Webber  

PubMed Central

The objective of the present study was to investigate the optimal nutritional requirements for mycelial growth and sporulation of entomopathogenic fungus Aschersonia aleyrodis Webber by orthogonal layout methods. Herein the order of effects of nutrient components on mycelial growth was tryptone > Ca2+ > soluble starch > folacin, corresponding to the following optimal concentrations: 1.58% Soluble Starch, 3.16% Tryptone, 0.2 mmol l-1 Ca2+ and 0.005% Folacin. The optimal concentration of each factors for sporulation was 1.16% lactose, 0.394% tryptone, 0.4 mmol l-1 Fe2+ and 0.00125% VB1, and the effects of medium components on sporulation were found to be in the order lactose > VB1 > Fe2+ > tryptone. Under the optimal culture conditions, the maximum production of mycelial growth achieved 20.05 g l-1 after 7 days of fermentation, while the maximum spore yield reached 5.23 ×1010 spores l-1 after 22 days of cultivation. This is the first report on optimization of nutritional requirements and design of simplified semi-synthetic media for mycelial growth and sporulation of A. aleyrodis.

Zhu, Yanping; Pan, Jieru; Qiu, Junzhi; Guan, Xiong

2008-01-01

45

Welfare-reducing growth despite individual and government optimization  

Microsoft Academic Search

.   In the presence of substantial relative-income effects and environmental disruption effects, economic growth may be welfare-reducing\\u000a even if each and all individuals are optimizing and eagerly trying to make more money and the government also maximizes the\\u000a welfare of individuals by the choice of income-tax rate and the ratio devoted to the abatement of environmental disruption.\\u000a Welfare-reducing growth may

Siang Ng; Yew-Kwang Ng

2001-01-01

46

A Study of the Effects of the Accelerated Reader Program on Fifth Grade Students' Reading Achievement Growth  

ERIC Educational Resources Information Center

|The purpose of this study was to compare the reading achievement growth of fifth grade students following a year of participation in the Accelerated Reader program with the reading achievement growth of fifth grade students who did not participate in the Accelerated Reader program. The Terra Nova standardized achievement test was used as the…

Melton, Cindy M.; Smothers, Bobbie C.; Anderson, Eugene; Fulton, Ray; Replogle, William H.; Thomas, Lisa

2004-01-01

47

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

PubMed

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

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

2009-07-01

48

OPTIMAL GROWTH AND SECONDARY METABOLITE PRODUCTION FROM COTTON HAIRY ROOTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

49

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.

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

2013-01-01

50

Development of 4H--SiC Epitaxial Growth Technique Achieving High Growth Rate and Large-Area Uniformity  

NASA Astrophysics Data System (ADS)

A vertical hot-wall epi-reactor that makes it possible to simultaneously achieve a high growth rate and large-area uniformity has been developed. A maximum growth rate of 250 ?m/h is achieved with a mirror-like morphology at 1650 ?. Under a modified epi-reactor setup, a thickness uniformity of 1.1% and a doping uniformity of 6.7% for a 65-mm-radius area are achieved while maintaining a high growth rate of 79 ?m/h. A low doping concentration of ˜1× 1013 cm-3 is obtained for a 50-mm-radius area. The low-temperature photoluminescence (LTPL) spectrum shows the predominance of free exciton peaks with only few impurity-related peaks and the L1 peak below detection limit. The deep level transient spectroscopy (DLTS) measurement for an epilayer grown at 80 ?m/h shows low trap concentrations of Z1/2: 1.2× 1012 and EH6/7: 6.3× 1011 cm-3. A 280-?m-thick epilayer with a RMS roughness of 0.2 nm and a carrier lifetime of ˜1 ?s is obtained.

Ito, Masahiko; Storasta, Liutauras; Tsuchida, Hidekazu

2008-01-01

51

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

Microsoft Academic Search

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

Patricia Ann Muller

1999-01-01

52

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

Microsoft Academic Search

The extremes of birth weight and preterm birth are known to result in a host of adverse outcomes, yet studies to date largely have used cross-sectional designs and variable-centered methods to understand long-term sequelae. Growth mixture modeling (GMM) that utilizes an integrated person- and variable-centered approach was applied to identify latent classes of achievement from a cohort of school-age children

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

2009-01-01

53

CROSS-GRADIENT GROWTH BENCH FOR THE OPTIMIZATION OF PLANT GROWTH CONDITIONS  

Microsoft Academic Search

TISCHNER T. and VEISZ O. Cross-gradient growth bench for the optimization of plant growth conditions. BIOTRONICS 25, 89-97, 1996. One of the most important criteria to be met by traditional climatic plant growth equipment is that the programmed environmental conditions should be completely homogeneous, i.e. all the experimental plants in the given phytotron unit should be exposed to identical environmental

T. TISCHNER; O. VEISZ

54

Optimal perturbation growth and bypass transition in mixing layers  

NASA Astrophysics Data System (ADS)

Hyperbolic mixing layers are strongly unstable to the normal-mode Kelvin-Helmholtz instability (KHI). At finite amplitude, KHI billows are unstable to the hyperbolic instability, which becomes streamwise-aligned braid-centred rib vortices that trigger turbulence transition. However, the underlying linear operator is non-normal, and so there may be transient non-normal-mode perturbations. We use numerically-calculated power iteration of the linear Navier-Stokes operator and its adjoint to identify perturbations whose energy grows most rapidly over finite times, and also investigate the nonlinear evolution of these perturbations using nonlinear direct numerical simulations. If the energy of the perturbation is optimized over sufficiently long times, the optimal perturbation is unsurprisingly closely related to the KHI normal mode, and the nonlinear evolution of this perturbation exhibits only a slightly enhanced transient growth compared to the KHI. Furthermore, the long-time optimal perturbation of a time-evolving KHI billow is essentially the hyperbolic instability. However, if the perturbation growth is optimized over short times, an inherently three-dimensional non-normal mode is identified, which in our nonlinear simulations can trigger `bypass' transition without any development of the primary KH instability. The growth mechanism and structure of this mode will be discussed.

Iams, Sarah M.; Caulfield, C. P.; Chomaz, J.-M.

2006-11-01

55

Optimal Culture Conditions for Mycelial Growth of Lignosus rhinocerus.  

PubMed

Lignosus rhinocerus is a macrofungus that belongs to Polyporaceae and is native to tropical regions. This highly priced mushroom has been used as folk medicine to treat diseases by indigenous people. As a preliminary study to develop a culture method for edible mushrooms, the cultural characteristics of L. rhinocerus were investigated in a range of culture media under different environmental conditions. Mycelial growth of this mushroom was compared on culture media composed of various carbon and nitrogen sources in addition to C/N ratios. The optimal conditions for mycelial growth were 30? at pH 6 and 7. Rapid mycelial growth of L. rhinocerus was observed on glucose-peptone and yeast extract peptone dextrose media. Carbon and nitrogen sources promoting mycelial growth of L. rhinocerus were glucose and potassium nitrate, respectively. The optimum C/N ratio was approximately 10 : 1 using 2% glucose supplemented as a carbon source in the basal media. PMID:22783083

Lai, W H; Siti Murni, M J; Fauzi, D; Abas Mazni, O; Saleh, N M

2011-06-16

56

Comparison of linear and nonlinear optimal perturbation transient growth in plane Couette flow  

NASA Astrophysics Data System (ADS)

Previous approaches to the question of transient growth have focused upon the study of linearised disturbances, with the assumption that it is the growth in the linear regime of linear optimal perturbations (LOPs) that nevertheless lead to a nonlinear regime and hence trigger the transition to turbulence. In this study we take a different approach by considering the full nonlinear problem. We look to extend the work considering pipe flow of Pringle (C. C. T. Pringle Ph.D. Bristol 2009) and use variational techniques to examine both the spatial structure and the normalised kinetic energy growth (gain) achieved by nonlinear optimal perturbations (NLOPs) in plane Couette flow. We show that in certain circumstances the gain achieved by the NLOP is significantly larger and has a noticeably different (and more complex) spatial structure from its counterpart LOP. We investigate the dependence on initial perturbation energy of the maximum predicted gain for selected Reynolds numbers and optimization times and propose that these inherently nonlinear structures may well be more significant in the transition to turbulence than LOPs.

Rabin, S. M. E.; Caulfield, C. P.; Kerswell, R. R.

2010-11-01

57

The Optimal Growth of Tropical Sea Surface Temperature Anomalies  

Microsoft Academic Search

It is argued from SST observations for the period 1950-90 that the tropical Indo-Pacific ocean-atmosphere system may be described as a stable linear dynamical system driven by spatially coherent Gaussian white noise. Evidence is presented that the predictable component of SST anomaly growth is associated with the constructive interference of several damped normal modes after an optimal initial structure is

Cécile Penland; Prashant D. Sardeshmukh

1995-01-01

58

Optimal growth when environmental quality is a research asset  

Microsoft Academic Search

We advance an original assumption whereby a good state of the environment positively affects labor productivity in R&D such that deteriorating environmental quality negatively impacts R&D. We study the implications of this assumption for the optimal solution in an R&D-based model of growth, where the use of a non-renewable resource generates pollution. We show that in such a case, it

Christian Groth; Francesco Ricci

2011-01-01

59

Environmental, Background, and Psychological Variables Related to Optimizing Achievement and Career Motivation for High School Girls.  

ERIC Educational Resources Information Center

High achievement motivation and career choice were related to perceived support from the school and community. Psychological variables had little effect. Findings support a social learning theory of achievement. (JAC)

Farmer, Helen S.

1980-01-01

60

Achieving profitable growth in E and P: New strategies, business model  

SciTech Connect

Major changes in the oil and gas environment during the last decade and a half have necessitated significant course corrections in upstream business strategies. Exogenous factors such as privatization and the opening of new opportunity areas have caused significant shifts in company strategies to drive growth, while lingering low commodity prices have applied continuous pressure to reduce costs. Successful upstream players have changed their strategies--from frontier exploration to development/production new ventures and on to gas and power plays--and built the capabilities necessary to achieve profitable growth. Moreover, these companies have adopted a new business model, an organization paradigm based on process-driven networks of business units, accountability and pay-for-performance, empowered multidisciplinary teams, and best practice sharing.

Cavoulacos, P. [Booz, Allen and Hamilton, Washington, DC (United States); Deffarges, E. [Booz, Allen and Hamilton, San Francisco, CA (United States)

1997-05-26

61

Modeling and Simulation of a Shock Absorbing Shell for Ballistic Vests and Helmets to Achieve Optimal Protection  

Microsoft Academic Search

This work deals with the modeling and simulation of shock absorbing shells for ballistic vests and helmets to achieve optimal protection. Shock absorbing shell is modeled as a circular membrane with clamped edge. Symmetrical loading patterns were considered as follows: uniformly distributed pressure over the entire surface of the shell, uniformly distributed pressure over a part of the shell's surface,

Claudiu Valentin Suciu; Shuuhei Fukui; Yuuta Kimura

2011-01-01

62

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

63

Optimizing amorphous indium zinc oxide film growth for low residual stress and high electrical conductivity  

NASA Astrophysics Data System (ADS)

With recent advances in flexible electronics, there is a growing need for transparent conductors with optimum conductivity tailored to the application and nearly zero residual stress to ensure mechanical reliability. Within amorphous transparent conducting oxide (TCO) systems, a variety of sputter growth parameters have been shown to separately impact film stress and optoelectronic properties due to the complex nature of the deposition process. We apply a statistical design of experiments (DOE) approach to identify growth parameter–material property relationships in amorphous indium zinc oxide (a-IZO) thin films and observed large, compressive residual stresses in films grown under conditions typically used for the deposition of highly conductive samples. Power, growth pressure, oxygen partial pressure, and RF power ratio (RF/(RF + DC)) were varied according to a full-factorial test matrix and each film was characterized. The resulting regression model and analysis of variance (ANOVA) revealed significant contributions to the residual stress from individual growth parameters as well as interactions of different growth parameters, but no conditions were found within the initial growth space that simultaneously produced low residual stress and high electrical conductivity. Extrapolation of the model results to lower oxygen partial pressures, combined with prior knowledge of conductivity–growth parameter relationships in the IZO system, allowed the selection of two promising growth conditions that were both empirically verified to achieve nearly zero residual stress and electrical conductivities >1480 S/cm. This work shows that a-IZO can be simultaneously optimized for high conductivity and low residual stress.

Kumar, Mukesh; Sigdel, A. K.; Gennett, T.; Berry, J. J.; Perkins, J. D.; Ginley, D. S.; Packard, C. E.

2013-10-01

64

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

2012-12-20

65

Inverse-optimized 3D conformal planning: Minimizing complexity while achieving equivalence with beamlet IMRT in multiple clinical sites  

PubMed Central

Purpose: Inverse planned intensity modulated radiation therapy (IMRT) has helped many centers implement highly conformal treatment planning with beamlet-based techniques. The many comparisons between IMRT and 3D conformal (3DCRT) plans, however, have been limited because most 3DCRT plans are forward-planned while IMRT plans utilize inverse planning, meaning both optimization and delivery techniques are different. This work avoids that problem by comparing 3D plans generated with a unique inverse planning method for 3DCRT called inverse-optimized 3D (IO-3D) conformal planning. Since IO-3D and the beamlet IMRT to which it is compared use the same optimization techniques, cost functions, and plan evaluation tools, direct comparisons between IMRT and simple, optimized IO-3D plans are possible. Though IO-3D has some similarity to direct aperture optimization (DAO), since it directly optimizes the apertures used, IO-3D is specifically designed for 3DCRT fields (i.e., 1–2 apertures per beam) rather than starting with IMRT-like modulation and then optimizing aperture shapes. The two algorithms are very different in design, implementation, and use. The goals of this work include using IO-3D to evaluate how close simple but optimized IO-3D plans come to nonconstrained beamlet IMRT, showing that optimization, rather than modulation, may be the most important aspect of IMRT (for some sites). Methods: The IO-3D dose calculation and optimization functionality is integrated in the in-house 3D planning/optimization system. New features include random point dose calculation distributions, costlet and cost function capabilities, fast dose volume histogram (DVH) and plan evaluation tools, optimization search strategies designed for IO-3D, and an improved, reimplemented edge/octree calculation algorithm. The IO-3D optimization, in distinction to DAO, is designed to optimize 3D conformal plans (one to two segments per beam) and optimizes MLC segment shapes and weights with various user-controllable search strategies which optimize plans without beamlet or pencil beam approximations. IO-3D allows comparisons of beamlet, multisegment, and conformal plans optimized using the same cost functions, dose points, and plan evaluation metrics, so quantitative comparisons are straightforward. Here, comparisons of IO-3D and beamlet IMRT techniques are presented for breast, brain, liver, and lung plans. Results: IO-3D achieves high quality results comparable to beamlet IMRT, for many situations. Though the IO-3D plans have many fewer degrees of freedom for the optimization, this work finds that IO-3D plans with only one to two segments per beam are dosimetrically equivalent (or nearly so) to the beamlet IMRT plans, for several sites. IO-3D also reduces plan complexity significantly. Here, monitor units per fraction (MU/Fx) for IO-3D plans were 22%–68% less than that for the 1 cm?×?1 cm beamlet IMRT plans and 72%–84% than the 0.5 cm?×?0.5 cm beamlet IMRT plans. Conclusions: The unique IO-3D algorithm illustrates that inverse planning can achieve high quality 3D conformal plans equivalent (or nearly so) to unconstrained beamlet IMRT plans, for many sites. IO-3D thus provides the potential to optimize flat or few-segment 3DCRT plans, creating less complex optimized plans which are efficient and simple to deliver. The less complex IO-3D plans have operational advantages for scenarios including adaptive replanning, cases with interfraction and intrafraction motion, and pediatric patients.

Fraass, Benedick A.; Steers, Jennifer M.; Matuszak, Martha M.; McShan, Daniel L.

2012-01-01

66

Optimization of biomass composition explains microbial growth-stoichiometry relationships.  

PubMed

Integrating microbial physiology and biomass stoichiometry opens far-reaching possibilities for linking microbial dynamics to ecosystem processes. For example, the growth-rate hypothesis (GRH) predicts positive correlations among growth rate, RNA content, and biomass phosphorus (P) content. Such relationships have been used to infer patterns of microbial activity, resource availability, and nutrient recycling in ecosystems. However, for microorganisms it is unclear under which resource conditions the GRH applies. We developed a model to test whether the response of microbial biomass stoichiometry to variable resource stoichiometry can be explained by a trade-off among cellular components that maximizes growth. The results show mechanistically why the GRH is valid under P limitation but not under N limitation. We also show why variability of growth rate-biomass stoichiometry relationships is lower under P limitation than under N or C limitation. These theoretical results are supported by experimental data on macromolecular composition (RNA, DNA, and protein) and biomass stoichiometry from two different bacteria. In addition, compared to a model with strictly homeostatic biomass, the optimization mechanism we suggest results in increased microbial N and P mineralization during organic-matter decomposition. Therefore, this mechanism may also have important implications for our understanding of nutrient cycling in ecosystems. PMID:21460549

Franklin, Oskar; Hall, Edward K; Kaiser, Christina; Battin, Tom J; Richter, Andreas

2011-02-01

67

Optimal growth strategies of larval helminths in their intermediate hosts.  

PubMed

We consider optimal growth of larval stages in complex parasite life cycles where there is no constraint because of host immune responses. Our model predicts an individual's asymptotic size in its intermediate host, with and without competition from conspecific larvae. We match observed variations in larval growth patterns in pseudophyllid cestodes with theoretical predictions of our model. If survival of the host is vital for transmission, larvae should reduce asymptotic size as intensity increases, to avoid killing the host. The life history strategy (LHS) model predicts a size reduction <1/intensity, thus increasing the parasite burden on the host. We discuss whether body size of competing parasites is an evolved LHS or simply reflects resource constraints (RC) on growth fixed by the host, leading to a constant total burden with intensity. Growth under competition appears comparable with "the tragedy of the commons", much analysed in social sciences. Our LHS prediction suggests that evolution generates a solution that seems cooperative but is actually selfish. PMID:14635879

Parker, G A; Chubb, J C; Roberts, G N; Michaud, M; Milinski, M

2003-01-01

68

Legionella pneumophilaRequires Polyamines for Optimal Intracellular Growth ?  

PubMed Central

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

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

2011-01-01

69

Fairness: How to Achieve It and How to Optimize in a Fair-Division Procedure  

ERIC Educational Resources Information Center

|A simple and practical application of mathematics is for fairly resolving the dispute of division of items for which two parties have equal claim. Basic properties of fair division are explained, which would enable students to learn concepts on optimization without introducing calculus.|

Jones, Michael A.; Cohen, Stanley F.

2004-01-01

70

Using optimization to achieve efficient quality of service in voice over IP networks  

Microsoft Academic Search

For Internet telephony to be a viable alternative to the public switch telephone network (PSTN), efficient and high quality communications are required. This paper proposes an optimization algorithm that selects parameters like the coding scheme, packet loss bound, and maximum link utilization level in a voice over IP (VoIP) network The goal is to deliver guaranteed quality of service (for

Michael Todd Gardner; Victor S. Frost; David W. Petr

2003-01-01

71

Academic achievement and psychological adjustment in short children. The National Cooperative Growth Study.  

PubMed

Limited information is available on the educational and behavioral functioning of short children. Through 27 participating medical centers, we administered a battery of psychologic tests to 166 children referred for growth hormone (GH) treatment (5 to 16 years) who were below the third percentile for height (mean height = -2.7 SD). The sample consisted of 86 children with isolated growth-hormone deficiency (GHD) and 80 children with idiopathic short stature (ISS). Despite average intelligence, absence of significant family dysfunction, and advantaged social background, a large number of children had academic underachievement. Both groups showed significant discrepancy (p < .01) between IQ and achievement scores in reading (6%), spelling (10%), and arithmetic (13%) and a higher-than-expected rate of behavior problems (GHD, 12%, p < .0001; ISS, 10%, p < .0001). Behavior problems included elevated rates of internalizing behavior (e.g., anxiety, somatic complaints) and externalizing behavior (e.g., impulsive, distractable, attention-seeking). Social competence was reduced in school-related activities for GHD patients (6%, p < .03). The high frequency of underachievement, behavior problems, and reduced social competency in these children suggests that short stature itself may predispose them to some of their difficulties. Alternately, parents of short, underachieving children may be more likely to seek help. In addition, some problems may be caused by factors related to specific diagnoses. PMID:8195431

Stabler, B; Clopper, R R; Siegel, P T; Stoppani, C; Compton, P G; Underwood, L E

1994-02-01

72

Combined expression of A1 and A20 achieves optimal protection of renal proximal tubular epithelial cells  

Microsoft Academic Search

Combined expression of A1 and A20 achieves optimal protection of renal proximal tubular epithelial cells.BackgroundApoptotic death of renal proximal tubular epithelial cells (RPTECs) is a feature of acute and chronic renal failure. RPTECs are directly damaged by ischemia, inflammatory, and cytotoxic mediators but also contribute to their own demise by up-regulating proinflammatory nuclear factor-kappaB (NF-?B)–dependent proteins. In endothelial cells, the

UTA KUNTER; SOIZIC DANIEL; MARIA B ARVELO; JEAN CHOI; TALA SHUKRI; VIRENDRA I PATEL; CHRISTOPHER R LONGO; SALVATORE T SCALI; GAUTAM SHRIKHANDE; EDUARDO ROCHA; EVA CZISMADIA; CHRISTINA MOTTLEY; SHANE T GREY; JÜRGEN FLOEGE; CHRISTIANE FERRAN

2005-01-01

73

Optimization of Composite Material System and Lay-up to Achieve Minimum Weight Pressure Vessel  

NASA Astrophysics Data System (ADS)

The use of composite pressure vessels particularly in the aerospace industry is escalating rapidly because of their superiority in directional strength and colossal weight advantage. The present work elucidates the procedure to optimize the lay-up for composite pressure vessel using finite element analysis and calculate the relative weight saving compared with the reference metallic pressure vessel. The determination of proper fiber orientation and laminate thickness is very important to decrease manufacturing difficulties and increase structural efficiency. In the present work different lay-up sequences for laminates including, cross-ply [ 0 m /90 n ] s , angle-ply [ ±?] ns , [ 90/±?] ns and [ 0/±?] ns , are analyzed. The lay-up sequence, orientation and laminate thickness (number of layers) are optimized for three candidate composite materials S-glass/epoxy, Kevlar/epoxy and Carbon/epoxy. Finite element analysis of composite pressure vessel is performed by using commercial finite element code ANSYS and utilizing the capabilities of ANSYS Parametric Design Language and Design Optimization module to automate the process of optimization. For verification, a code is developed in MATLAB based on classical lamination theory; incorporating Tsai-Wu failure criterion for first-ply failure (FPF). The results of the MATLAB code shows its effectiveness in theoretical prediction of first-ply failure strengths of laminated composite pressure vessels and close agreement with the FEA results. The optimization results shows that for all the composite material systems considered, the angle-ply [ ±?] ns is the optimum lay-up. For given fixed ply thickness the total thickness of laminate is obtained resulting in factor of safety slightly higher than two. Both Carbon/epoxy and Kevlar/Epoxy resulted in approximately same laminate thickness and considerable percentage of weight saving, but S-glass/epoxy resulted in weight increment.

Mian, Haris Hameed; Wang, Gang; Dar, Uzair Ahmed; Zhang, Weihong

2013-10-01

74

Optimization of Composite Material System and Lay-up to Achieve Minimum Weight Pressure Vessel  

NASA Astrophysics Data System (ADS)

The use of composite pressure vessels particularly in the aerospace industry is escalating rapidly because of their superiority in directional strength and colossal weight advantage. The present work elucidates the procedure to optimize the lay-up for composite pressure vessel using finite element analysis and calculate the relative weight saving compared with the reference metallic pressure vessel. The determination of proper fiber orientation and laminate thickness is very important to decrease manufacturing difficulties and increase structural efficiency. In the present work different lay-up sequences for laminates including, cross-ply [0 m /90 n ] s , angle-ply [±?] ns , [90/±?] ns and [0/±?] ns , are analyzed. The lay-up sequence, orientation and laminate thickness (number of layers) are optimized for three candidate composite materials S-glass/epoxy, Kevlar/epoxy and Carbon/epoxy. Finite element analysis of composite pressure vessel is performed by using commercial finite element code ANSYS and utilizing the capabilities of ANSYS Parametric Design Language and Design Optimization module to automate the process of optimization. For verification, a code is developed in MATLAB based on classical lamination theory; incorporating Tsai-Wu failure criterion for first-ply failure (FPF). The results of the MATLAB code shows its effectiveness in theoretical prediction of first-ply failure strengths of laminated composite pressure vessels and close agreement with the FEA results. The optimization results shows that for all the composite material systems considered, the angle-ply [±?] ns is the optimum lay-up. For given fixed ply thickness the total thickness of laminate is obtained resulting in factor of safety slightly higher than two. Both Carbon/epoxy and Kevlar/Epoxy resulted in approximately same laminate thickness and considerable percentage of weight saving, but S-glass/epoxy resulted in weight increment.

Mian, Haris Hameed; Wang, Gang; Dar, Uzair Ahmed; Zhang, Weihong

2013-01-01

75

Achievement growth in children with learning difficulties in mathematics: Findings of a two-year longitudinal study  

Microsoft Academic Search

The reading and mathematics growth of 180 children was examined over 4 points, spanning 2nd and 3rd grades. Initially, 4 achievement groups were identified: difficulties in mathematics but not in reading (MD only), difficulties in mathematics as well as in reading (MD-RD), difficulties in reading but not in mathematics (RD only), and normal achievement in mathematics and in reading. When

Nancy C. Jordon; David Kaplan; Laurie B. Hanich

2002-01-01

76

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

SciTech Connect

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

Knupp, P.M.

1999-01-18

77

Optimal control: its application to economic growth and natural resource depletion  

Microsoft Academic Search

The application of optimal control to economic growth and natural resource depletion is described in this paper. The basic equations of optimal control are introduced, and a simple model for economic growth is described. The optimal consumption path is then deteimined for this problem subject to the maximization of a welfare integral. The model is then generalized so that production

David N. Burghes; Robert Davison; George Yarrow

1977-01-01

78

How to Achieve Optimal Correction of Acidosis in End-Stage Renal Failure Patients  

Microsoft Academic Search

Metabolic acidosis appears to be responsible for a variety of detrimental clinical and biological effects in uremic subjects, making its correction with dialysis mandatory. By utilizing the kinetic approach, pre- and post-dialysis target levels to be achieved by dialysis can be defined. Although a clear-cut bicarbonate concentration threshold, below which deleterious effects appear, has not yet been defined, it seems

Pietro Zucchelli; Antonio Santoro

1995-01-01

79

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

Microsoft Academic Search

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

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

2011-01-01

80

Metal-binding sites are designed to achieve optimal mechanical and signaling properties  

PubMed Central

Many proteins require bound metals to achieve their function. We take advantage of increasing structural data on metal-binding proteins to elucidate three properties: the involvement of metal-binding sites in the global dynamics of the protein, predicted by elastic network models, their exposure/burial to solvent, and their signal-processing properties indicated by Markovian stochastics analysis. Systematic analysis of a dataset of 145 structures reveals that the residues that coordinate metal ions enjoy remarkably efficient and precise signal transduction properties. These properties are rationalized in terms of their physical properties: participation in hinge sites that control the softest modes collectively accessible to the protein and occupancy of central positions minimally exposed to solvent. Our observations suggest that metal-binding sites may have been evolutionary selected to achieve optimum allosteric communication. They also provide insights into basic principles for designing metal-binding sites, which are verified to be met by recently designed de novo metal-binding proteins.

Dutta, Anindita; Bahar, Ivet

2010-01-01

81

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

PubMed

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

2013-04-01

82

Optimizing the growth of vanadyl-phthalocyanine thin films for high-mobility organic thin-film transistors  

Microsoft Academic Search

To achieve high-mobility organic thin-film transistors (OTFTs), growth of vacuum-evaporated vanadyl-phthalocyanine (VOPc) thin films as the active layer was studied and optimized by varying the process conditions of the substrate temperature, deposition rate, and dielectric type. On the popularly used SiO2 gate dielectric, the surface morphology of the VOPc thin film exhibited closely packed terraced grains when the substrate temperature

X. J. Yu; J. B. Xu; W. Y. Cheung; N. Ke

2007-01-01

83

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

84

Axenization and optimization of in vitro growth of clonal cultures of Tetratrichomonas gallinarum and Trichomonas gallinae  

Microsoft Academic Search

A rapid and simple procedure was established to obtain clonal axenic cultures of Tetratrichomonas gallinarum and Trichomonas gallinae and to optimize their in vitro growth conditions. Medium 199 was used for axenization of two genetically different clones of T. gallinarum and T. gallinae. Six different media were used to optimize the growth behaviour of axenically grown parasites: Medium 199, TYM,

Aziza Amin; Claudia Neubauer; Dieter Liebhart; Elvira Grabensteiner; Michael Hess

2010-01-01

85

Potential relative increment (PRI): a new method to empirically derive optimal tree diameter growth  

Microsoft Academic Search

Potential relative increment (PRI) is a new method to derive optimal diameter growth equations using inventory information from a large public database. Optimal growth equations for 24 species were developed using plot and tree records from several states (Michigan, Minnesota, and Wisconsin) of the north central US. Most species were represented by thousands of individuals measured across an extensive geographic

Don C. Bragg

2001-01-01

86

Estimating Correlates of Growth between Mathematics and Science Achievement via a Multivariate Multilevel Design with Latent Variables  

ERIC Educational Resources Information Center

|The purpose of the present study was to improve a multivariate multilevel model in the research literature which estimates the consistency in the rates of growth between mathematics and science achievement among students and schools. We introduced a new multivariate multilevel model via a latent variable approach. Data from the Longitudinal Study…

Ma, Lingling; Ma, Xin

2005-01-01

87

The Relationship of Selected Measures of Proprioception to Physical Growth, Motor Performance, and Academic Achievement in Young Children.  

ERIC Educational Resources Information Center

|This study investigates the relationship of selected measures of proprioception to measures of physical growth, motor performance, and academic achievement in young children. Measures were obtained from 321 boys and girls attending kindergarten and first and second grade. Sample correlation matrices were computed on all variables at each grade…

Haubenstricker, John L.; Milne, D. Conrad

88

Growth Mixture Modeling: Application to Reading Achievement Data from a Large-Scale Assessment  

ERIC Educational Resources Information Center

|The popularity of growth modeling has increased in psychological and cognitive development research as a means to investigate patterns of changes and differences between observation units over time. Random coefficient modeling, such as multilevel modeling and latent growth curve modeling as a special application of structural equation modeling…

Bilir, Mustafa Kuzey; Binici, Salih; Kamata, Akihito

2008-01-01

89

Assessing the Contribution of Distributed Leadership to School Improvement and Growth in Math Achievement  

Microsoft Academic Search

Although there has been sizable growth in the number of empirical studies of shared forms of leadership over the past decade, the bulk of this research has been descriptive. Relatively few published studies have investigated the impact of shared leadership on school improvement. This longitudinal study examines the effects of distributed leadership on school improvement and growth in student math

Ronald H. Heck; Philip Hallinger

2009-01-01

90

Optimizations to achieve high-level expression of cytochrome P450 proteins using Escherichia coli expression systems.  

PubMed

Recombinant expression of membrane-bound cytochrome P450s in bacterial expression systems provide a well-established system capable of producing large yields of catalytically active protein. As the biochemical knowledge regarding cytochrome P450s increases, so does the efficiency of protein expression through various modifications that do not disrupt the functional properties of the protein of interest. Changes such as N-terminal modifications, reduction of secondary mRNA structure, bacterial codon usage, selection of vector and host strain, as well as varying external growth conditions all appear to influence protein expression. Several optimizations are often required for sufficient expression of cytochrome P450s at the desired cellular localization. This review aims to comprehensively summarize and update the significant advances made in membrane protein P450 expression in bacterial expression systems. PMID:23973802

Zelasko, Susan; Palaria, Amrita; Das, Aditi

2013-08-20

91

Relative growth rates and the grazing optimization hypothesis  

Microsoft Academic Search

A mathematical analysis of the changes in plant relative growth rates necessary to increase aboveground production following grazing was conducted. The equation derived gives an isoline where production of a grazed and ungrazed plant will be the same. The equation has four variables (mean shoot relative growth rate, change in relative growth rate after grazing, grazing intensity, and recovery time)

D. W. Hilbert; D. M. Swift; J. K. Detling; M. I. Dyer

1981-01-01

92

Optimization of culture conditions to improve Helicobacter pylori growth in Ham's F-12 medium by response surface methodology.  

PubMed

Helicobacter pylori is a gastroduodenal pathogen that colonizes the human stomach and is the causal agent of gastric diseases. From the clinical and epidemiological point of view, enhancing and improving the growth of this bacterium in liquid media is an important goal to achieve in order to allow the performance of accurate physiological studies. The aim of this work was to optimize three culture conditions that influence the growth of H. pylori in the defined medium Ham s F-12 supplemented with 5 percent fetal bovine serum by using response surface methodology as a statistical technique to obtain the optimal conditions. The factors studied in this experimental design (Box-Behnken design) were the pH of the medium, the shaking speed (rpm) and the percentage of atmospheric oxygen, in a total of 17 experiments. The biomass specific growth rate was the response measured. The model was validated for pH and shaking speed. The percentage of atmospheric oxygen did not influence the growth for the range of values studied. At the optimal values found for pH and shaking speed, 8 and 130 rpm, respectively, a specific growth rate value of 0.164 h-1, corresponding to a maximal concentration of approximately 1.5x108 CFU/ml, was reached after 8 h. The experimental design strategy allowed, for the first time, the optimization of H. pylori growth in a semi-synthetic medium, which may be important to improve physiological and metabolic studies of this fastidious bacterium. PMID:23298481

Bessa, L J; Correia, D M; Cellini, L; Azevedo, N F; Rocha, I

93

Outcomes Assessment Related to Professional Growth and Achievements of Baccalaureate Dental Hygiene Graduates  

Microsoft Academic Search

The goals of the entry-level baccalaureate dental hygiene (DH) program at the University of California, San Francisco, include the preparation of scholars who will pursue additional study and research and the development of DH educators and leaders in the field of DH. The objective of this study was to evaluate whether the goals of the program were being achieved by

Dorothy J. Rowe; Jane A. Weintraub; Sara Shain; Judy Yamamoto; Margaret M. Walsh

94

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

95

A Latent Growth Curve Analysis of Reading Achievement for an At-Risk Population  

ERIC Educational Resources Information Center

|The development of reading skills from age seven until age 19 was investigated for children who were referred for special education preschool intervention using latent growth curve analysis (n=206). Approximately one-third of the study sample did not require special education services after preschool, providing a natural comparison group. Reading…

Beecher, Constance C.

2011-01-01

96

Achieving Inclusive Growth and Sustainable Development - Role of Innovative and Benchmarked KOSM Practices - A Case Study  

Microsoft Academic Search

This Case Study discusses the Innovative & Benchmarked KOSM (Information & Knowledge Organisation, Sharing and Management) Practices designed and being implemented in L&T- the Indian MNC, for Competitive Advantage, thereby Inclusive Growth and Sustainable Development in the New Millennium. This paper also deals in general perspective highlighting about the Top 12 Technological Revolutions that changed the World in the recent

S Vaithiyanathan

2012-01-01

97

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

ERIC Educational Resources Information Center

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

Fegley, Alan D.

2010-01-01

98

Assessing the Contribution of Distributed Leadership to School Improvement and Growth in Math Achievement  

ERIC Educational Resources Information Center

|Although there has been sizable growth in the number of empirical studies of shared forms of leadership over the past decade, the bulk of this research has been descriptive. Relatively few published studies have investigated the impact of shared leadership on school improvement. This longitudinal study examines the effects of distributed…

Heck, Ronald H.; Hallinger, Philip

2009-01-01

99

DASEES: A Tripartite Decision Analysis Framework to Achieve Sustainable Environment, Economy & Society Growth and Management Goals  

EPA Science Inventory

Many of Societies management and growth decisions are often made without a balanced consideration of pertinent factors from environmental, economic and societal perspectives. All three of these areas are key players in many of the decisions facing societies as they strive to ope...

100

Growth optimization for p-n junction placement in the integration of heterojunction bipolar transistors and quantum well modulators on InP  

Microsoft Academic Search

We demonstrate the necessary conditions for successful metalorganic vapor phase epitaxy (MOVPE) growth of InGaAs-InP-based heterojunction bipolar transistor (HBT) layers on p-i-n InGaAsP-InGaAsP quantum-well electroabsorption modulators. Optimization of the doping profile in the uppermost p-cladding layer of the modulator stack was achieved to obtain suitable p-n junction placement after the final HBT growth. Photoluminescence, electron beam induced current traces, scanning

M. T. Camargo Silva; J. E. Zucker; L. R. Carrion; C. H. Joyner; A. G. Dentai

2000-01-01

101

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

102

The number of procedures required to achieve optimal competency with male circumcision: findings from a randomized trial in Rakai, Uganda  

PubMed Central

Objective To assess the number of procedures required to achieve optimal competency (time required for surgery with minimal adverse events) in Rakai, Uganda, and thus facilitate the development of guidelines for training providers, as male circumcision reduces the acquisition of human immunodeficiency virus (HIV) in men and is recommended for HIV prevention. Patients and methods In a randomized trial, 3011 men were circumcised, using the sleeve method, by six physicians who had completed training, which included 15–20 supervised procedures. The duration of surgery from local anaesthesia to wound closure, moderate or severe surgery-related adverse events (AEs), and wound healing were assessed in relation to the number of procedures done by each physician. Results The median age of the patients was 24 years. The number of procedures per surgeon was 20–981. The mean time required to complete surgery was ?40 min for the first 100 procedures and declined to 25 min for the subsequent 100 circumcisions. After controlling for the number of procedures there was no significant difference in duration of the surgery by patient HIV status or age. The rate of moderate and severe AEs was 8.8% (10/114) for the first 19 unsupervised procedures after training, 4.0% for the next 20–99 (13/328) and 2.0% for the last 100 (P for trend, 0.003). All AEs resolved with management. Conclusion The completion of more than 100 circumcisions was required before newly trained physicians achieved the optimum duration of surgery. AEs were higher immediately after training and additional supervision is needed for at least the first 20 procedures after completing training.

Kiggundu, Valerian; Watya, Stephen; Kigozi, Godfrey; Serwadda, David; Nalugoda, Fred; Buwembo, Denis; Settuba, Adrian; Anyokorit, Margaret; Nkale, James; Kighoma, Noah; Sempiija, Victor; Wawer, Maria; Gray, Ronald H.

2009-01-01

103

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

PubMed

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

Chambers, James Alan; Ray, Peter Damian

2009-11-01

104

Optimization of Network Configuration in Large Distribution Systems Using Plant Growth Simulation Algorithm  

Microsoft Academic Search

Optimization of network configuration involving the switch statuses is important for the operation in the distribution system. This paper presents a network configuration optimization approach based on the plant growth simulation algorithm (PGSA), which is specially suited to large-scale distribution systems. An elegant design method of the decision variables, which describes the radial feature of the distribution network and considerably

Chun Wang; Hao Zhong Cheng

2008-01-01

105

Selection of optimal measures of growth and reproduction for the sublethal Leptocheirus plumulosus sediment bioassay  

Microsoft Academic Search

This article describes the selection process used to identify optimal measures of growth and reproduction for the proposed 28-d sublethal sediment bioassay with the estuarine amphipod Leptocheirus plumulosus. The authors used four criteria (relevance of each measure to its respective endpoint, signal-to-noise ratio, redundancy relative to other measures of the same endpoint, and cost) to evaluate nine growth and seven

Brian R. Gray; R. B. Wright; B. M. Duke; J. D. Farrar; V. L. Jr. Emery; D. L. Brandon; David W. Moore

1998-01-01

106

The simple analytics of optimal growth with illegal migrants  

Microsoft Academic Search

This paper analyses the impact of illegal migration on the optimal path of domestic (resident) consumption. The analysis draws two important conclusions. First, if illegal migrants and domestic labour are perfect substitutes, illegal migration necessarily lowers the long-run per capita consumption of domestic residents. Second, if illegal migrants and domestic labour are imperfect substitutes, the effect on the long-run per

Bharat R. Hazari; Pasquale M. Sgro

2003-01-01

107

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

Microsoft Academic Search

We employed systematic mixture analysis to determine optimal levels of acetate, propionate, and butyrate for cell growth and\\u000a polyhydroxyalkanoate (PHA) production by Ralstonia eutropha H16. Butyrate was the preferred acid for robust cell growth and high PHA production. The 3-hydroxyvalerate content in the\\u000a resulting PHA depended on the proportion of propionate initially present in the growth medium. The proportion of

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

2010-01-01

108

Evaluating and optimizing horticultural regimes in space plant growth facilities  

Microsoft Academic Search

In designing innovative Space Plant Growth Facilities (SPGF) for long duration space f ightl various limitations must be addressed including onboard resources: volume, energy consumption, heat transfer and crew labor expenditure. The required accuracy in evaluating onboard resources by using the equivalent mass methodology and applying it to the design of such facilities is not precise. This is due to

Y. Berkovich; R. Chetirkin; R. Wheeler; J. Sager

2002-01-01

109

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

110

Selection of optimal measures of growth and reproduction for the sublethal Leptocheirus plumulosus sediment bioassay  

SciTech Connect

This article describes the selection process used to identify optimal measures of growth and reproduction for the proposed 28-d sublethal sediment bioassay with the estuarine amphipod Leptocheirus plumulosus. The authors used four criteria (relevance of each measure to its respective endpoint, signal-to-noise ratio, redundancy relative to other measures of the same endpoint, and cost) to evaluate nine growth and seven reproductive measures. Optimal endpoint measures were identified as those receiving relatively high scores for all or most criteria. Measures of growth scored similarly on all criteria, except for cost. The cost of the pooled (female plus male) growth measures was substantially lower than the cost of the female and male growth measures because the latter required more labor (by approx. 25 min per replicate). Pooled dry weight was identified as the optimal growth measure over pooled length because the latter required additional labor and nonstandard software and equipment. Embryo and neonate measures of reproduction exhibited wide differences in labor costs but yielded similar scores for other criteria. In contrast, brooding measures of reproduction scored relatively low on endpoint relevance, signal-to-noise ratio, and redundancy criteria. The authors recommend neonates/survivor as the optimal measure of L. plumulosus reproduction because it exhibited high endpoint relevance and signal-to-noise ratios, was redundant to other reproductive measures, and required minimal time.

Gray, B.R.; Wright, R.B.; Duke, B.M.; Farrar, J.D. [AScI Corp., Vicksburg, MS (United States); Emery, V.L. Jr.; Brandon, D.L.; Moore, D.W. [Army Corps of Engineers, Vicksburg, MS (United States). Waterways Experiment Station

1998-11-01

111

Application of Plackett-Burman Design and Box-Behnken Design to Achieve Process Optimization for Geniposide Submicron Emulsion  

Microsoft Academic Search

The objective of this study was to prepare and characterize geniposide submicron emulsion (GP-SME) loaded the geniposide phytosomes (GP-PS) geniposide and optimize the process variables. The physicochemical properties of GP-PS obtained were investigated by means of differential scanning calorimetry. A screening experiment with Plackett-Burman design (PBD) and response surface methodology (RSM) with Box-Behnken design (BBD) was used to optimize the

Peng-Fei Yue; Qin Zheng; Bin Wu; Peng-Yi Hu; Zhen-Feng Wu; Ming Yang

2011-01-01

112

Application of Plackett-Burman Design and Box-Behnken Design to Achieve Process Optimization for Geniposide Submicron Emulsion  

Microsoft Academic Search

The objective of this study was to prepare and characterize geniposide submicron emulsion (GP-SME) loaded the geniposide phytosomes (GP-PS) geniposide and optimize the process variables. The physicochemical properties of GP-PS obtained were investigated by means of differential scanning calorimetry. A screening experiment with Plackett-Burman design and response surface methodology with Box-Behnken design was used to optimize the process parameters of

Peng-Fei Yue; Qin Zheng; Bin Wu; Peng-Yi Hu; Zhen-Feng Wu; Ming Yang

2012-01-01

113

PARALLEL SCHEDULING OF MULTICLASS M\\/M\\/m QUEUES: APPROXIMATE AND HEAVY-TRAFFIC OPTIMIZATION OF ACHIEVABLE PERFORMANCE  

Microsoft Academic Search

We address the problem of scheduling a multiclass M\\/M\\/m queue with Bernoulli feedback on m parallel servers to minimize time-average linear holding costs. We analyze the performance of a heuristic priority-index rule, which extends Klimov's optimal solution to the single- server case: servers select preemptively customers with larger Klimov indices. We present closed-form suboptimality bounds (approximate optimality) for Klimov's rule,

KEVIN D. GLAZEBROOK; JOSÉ NIÑO-MORA

2001-01-01

114

Posttraumatic Growth and Optimism in Health-Related Trauma: A Systematic Review  

Microsoft Academic Search

Posttraumatic growth (PTG) research is an emerging area of empirical study, especially within the field of clinical health\\u000a psychology. Much of the research in this area has thus far focused on determining the correlates and predictors of PTG. This\\u000a systematic review aimed to evaluate the association between posttraumatic growth and dispositional optimism, specifically\\u000a in relation to health traumas. Empirical studies

Lucy Bostock; Alia I. Sheikh; Stephen Barton

2009-01-01

115

Optical spectroscopy and optimal crystal growth of some Cr4+-doped garnets  

Microsoft Academic Search

This paper describes the growth of single crystals of Cr4+ -doped Y3 Ga5 O12 (YGG) and Y3 Al5 O12 (YAG). Control of melt composition and post-growth annealing yields material that contains optimal concentrations of Cr4+ ions in distorted tetrahedral sites normally occupied by Ga3+ ions in YGG and Al3+ ions in YAG. Both Cr4+ -doped garnets exhibit strong visible and

B. Henderson; H. G. Gallagher; T. P. J. Han; M. A. Scott

2000-01-01

116

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

117

An Optimized Design of Anode Shape Based on Artificial Neural Network for Achieving Highest X-ray Yield in Plasma Focus Device  

NASA Astrophysics Data System (ADS)

In this paper, an optimized design of anode shape in order to achieve highest X-ray yield in a plasma focus device filled with nitrogen gas based on artificial neural networks (ANNs) is presented. Multi-layer perceptron neural network structure with the back-propagation algorithm is used for the training of the proposed model. The model has achieved good agreement with the training data and has yielded satisfactory generalization. This shows that the ANN model is an accurate and reliable approach to predict the highest X-ray yield in plasma focus devices.

Hayati, M.; Roshani, G. H.; Abdi, H.; Rezaei, A.; Mahtab, M.

2013-08-01

118

Optimized Conditions for the Growth of Human Epidermal Cells in Culture  

Microsoft Academic Search

Methods have been optimized for the isolation, growth and passage of differentiating human epidermal cells in dispersed cell culture. Human neonatal foreskin epidermis was separated from dermis after floating the skin on trypsin. Keratinocytes were isolated by dissociation of epidermal sheets in calcium, magnesium-free phosphate buffered saline. Under culture conditions established for mouse keratinocytes, human epidermal cells retained epithelial morphology

Pamela Hawley-Nelson; James E. Sullivan; Margaret Kung; Henry Hennings; Stuart H. Yuspa

1980-01-01

119

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

Microsoft Academic Search

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

T. LECHIANCOLE; A. RICCIARDI; E. PARENTE

120

Nonmodal energy growth and optimal perturbations in compressible plane Couette flow  

Microsoft Academic Search

Nonmodal transient growth studies and an estimation of optimal perturbations have been made for the compressible plane Couette flow with three-dimensional disturbances. The steady mean flow is characterized by a nonuniform shear rate and a varying temperature across the wall-normal direction for an appropriate perfect gas model. The maximum amplification of perturbation energy over time, Gmax, is found to increase

M. Malik; Meheboob Alam; J. Dey

2006-01-01

121

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

122

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

Microsoft Academic Search

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

Wayne Penrod

2006-01-01

123

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

Microsoft Academic Search

The objective of this project is to demonstrate the use of an Integrated Combustion Optimization System to achieve NOâ 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-NOâ burners and advanced overfire air technology with various process measurement and control devices on the Holcomb Station

Wayne Penrod; David Moyeda

2003-01-01

124

Optimization of speed control algorithm to achieve minimum torque ripple for a switched reluctance motor drive via GA  

Microsoft Academic Search

This study presents a speed controller design for a switched reluctance (SR) motor in order to achieve minimum torque ripple and high control performance. First of all, SR motor convertor designed for soft chopping is chosen. This converter as well as producing less torque ripple, provides more degrees of freedom for SR motor drive controller. A PID controller and a

Hanif Tahersima; Mohammadjafar Kazemsaleh; Mohammadhossein Tahersima; Navid Hamedi

2011-01-01

125

Optimization of selection for growth in Menz Sheep while minimizing inbreeding depression in fitness traits  

PubMed Central

The genetic trends in fitness (inbreeding, fertility and survival) of a closed nucleus flock of Menz sheep under selection during ten years for increased body weight were investigated to evaluate the consequences of selection for body weight on fitness. A mate selection tool was used to optimize in retrospect the actual selection and matings conducted over the project period to assess if the observed genetic gains in body weight could have been achieved with a reduced level of inbreeding. In the actual selection, the genetic trends for yearling weight, fertility of ewes and survival of lambs were 0.81 kg, –0.00026% and 0.016% per generation. The average inbreeding coefficient remained zero for the first few generations and then tended to increase over generations. The genetic gains achieved with the optimized retrospective selection and matings were highly comparable with the observed values, the correlation between the average breeding values of lambs born from the actual and optimized matings over the years being 0.99. However, the level of inbreeding with the optimized mate selections remained zero until late in the years of selection. Our results suggest that an optimal selection strategy that considers both genetic merits and coancestry of mates should be adopted to sustain the Menz sheep breeding program.

2013-01-01

126

Optimal fetal growth for the Caucasian singleton and assessment of appropriateness of fetal growth: an analysis of a total population perinatal database  

Microsoft Academic Search

BACKGROUND: The appropriateness of an individual's intra uterine growth is now considered an important determinant of both short and long term outcomes, yet currently used measures have several shortcomings. This study demonstrates a method of assessing appropriateness of intrauterine growth based on the estimation of each individual's optimal newborn dimensions from routinely available perinatal data. Appropriateness of growth can then

Eve M Blair; Yingxin Liu; Nicholas H de Klerk; David M Lawrence

2005-01-01

127

The optimization of the growth on (111) gallium arsenide and (111) indium phosphide substrates by molecular beam epitaxy  

NASA Astrophysics Data System (ADS)

Growing on (111) oriented substrate has been long attracted much attentions due to the presence of piezoelectric field when the material is under strain. However, growing on this orientation still poses a great challenge to crystal grower due to the tendency of forming pyramidal facets along the <110> directions. This dissertation covers the optimization of the growth on (111) GaAs and (111) InP substrates using molecular beam epitaxy. The enhancement of the material performance due to the piezoelectric effects was also investigated in this dissertation. Growing on (111)A surface is very difficult due to the fact that the surface is terminated with group III atoms. On this surface, Si can either occupy the group III site, becomes a donor, or the group V site, becomes an acceptor, depending on the growth condition. Also, the group III terminated surface makes the epi-layer grown on (111)A substrates metal-rich under most of the growth conditions. Therefore, a high quality material is hard to obtain on (111)A surface. Whereas, growing on (111)B surface, Si always acts as a donor. High quality epi-layer can be achieved by employing high growth temperature, low V/III ratio and misoriented substrate. High quality AlGaAs/GaAs heterostructure has been grown on (111)B GaAs substrates. Two-dimensional electron gas (2DEG) Hall mobility of 7,200 cm 2/Vs with sheet density of 7.7 x 1011 cm -2 with a 134 A spacer layer at room temperature, and 90,000 cm2/Vs with sheet density of 6.2 x 1011 cm-2 at 77K have been achieved on (111)B GaAs. Excellent material has also been grown on (111)B InP. InAlAs/InGaAs heterostructure grown on (111)B InP gave a room temperature 2DEG Hall mobility of 11,200 cm 2/VS with sheet density of 3.0 x 1012 cm -2 with a 40 A spacer layer. At 77K, the 2DEG Hall mobility was 42,800 cm2/Vs with sheet density of 2.3 x 1012 cm-2. This heterostructure showed a 30% enhancement in 2DEG sheet density due to the piezoelectric effects. Excellent material has been grown on (111) surface using molecular beam epitaxy. This dissertation covers the optimal growth condition of (111)B GaAs and (111)B InP. With electrostatic analysis plus semiempirical approach, a simple equation for estimating the 2DEG sheet density is also presented in this dissertation.

Yeo, Hock Huat

128

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

2013-05-31

129

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

NASA Astrophysics Data System (ADS)

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

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

1992-03-01

130

A Surgical Option for Multilevel Anterior Lumbar Interbody Fusion with Ponte Osteotomy to Achieve Optimal Lumbar Lordosis and Sagittal Balance  

PubMed Central

Objective To document lumbar lordosis (LL) of the spine and its change during surgeries with the different height but the same angle setting of the anterior cage. Additionally, we attempted to determine if sufficient LL is achieved at different cage heights and to quantify the change in LL during multi-level anterior lumbar interbody fusion (ALIF). Methods The medical records and radiographs of 42 patients who underwent more than 2 level ALIFs between 2008 and 2009 were retrospectively reviewed. We evaluated 3 parameters seen on lateral whole spine radiographs : LL, pelvic incidence (PI), and sagittal vertical axis (SVA). The mean follow-up time was 28.1 months and the final follow-up radiographs of all patients were reviewed at least 2 years after surgery. Statistical analysis was performed using the paired t-tests. Results Lumbar lordosis had changed up to 30 degrees immediately and 2 years after surgery (preoperative mean LL, SVA : 22.45 degrees, 112.31 mm; immediate postoperative mean LL, SVA : 54.45 degrees, 37.36 mm; final follow-up mean LL, SVA : 49.56 degrees, 26.95 mm). Our goal of LL is to obtain as much PI as possible, preoperative mean PI value was 55.38±3.35. The pre-operative and two year post-surgery follow-up mean of the Japanese Orthopedic Association score were 9.2±0.6 and 13.2±0.6 (favorable outcome rate : 95%), respectively. In addition, we were able to obtain good clinical outcomes and sagittal balance with a subsidence rate of 22.7%. Conclusion We were able to achieve sufficient LL, such that it was similar to the PI, utilizing multi-level ALIF with the use of a tall cage with the same angle setting of the cage. We have found out that achieving sufficient lumbar lordosis and sagittal balance require an anterior lumbar cage with high angle and height.

Suh, Loo-Ree; Kim, Sung-Min; Lim, Young-Jin

2012-01-01

131

Optimize Flue Gas Settings to Promote Microalgae Growth in Photobioreactors via Computer Simulations.  

PubMed

Flue gas from power plants can promote algal cultivation and reduce greenhouse gas emissions(1). Microalgae not only capture solar energy more efficiently than plants(3), but also synthesize advanced biofuels(2-4). Generally, atmospheric CO2 is not a sufficient source for supporting maximal algal growth(5). On the other hand, the high concentrations of CO2 in industrial exhaust gases have adverse effects on algal physiology. Consequently, both cultivation conditions (such as nutrients and light) and the control of the flue gas flow into the photo-bioreactors are important to develop an efficient "flue gas to algae" system. Researchers have proposed different photobioreactor configurations(4,6) and cultivation strategies(7,8) with flue gas. Here, we present a protocol that demonstrates how to use models to predict the microalgal growth in response to flue gas settings. We perform both experimental illustration and model simulations to determine the favorable conditions for algal growth with flue gas. We develop a Monod-based model coupled with mass transfer and light intensity equations to simulate the microalgal growth in a homogenous photo-bioreactor. The model simulation compares algal growth and flue gas consumptions under different flue-gas settings. The model illustrates: 1) how algal growth is influenced by different volumetric mass transfer coefficients of CO2; 2) how we can find optimal CO2 concentration for algal growth via the dynamic optimization approach (DOA); 3) how we can design a rectangular on-off flue gas pulse to promote algal biomass growth and to reduce the usage of flue gas. On the experimental side, we present a protocol for growing Chlorella under the flue gas (generated by natural gas combustion). The experimental results qualitatively validate the model predictions that the high frequency flue gas pulses can significantly improve algal cultivation. PMID:24121788

He, Lian; Chen, Amelia B; Yu, Yi; Kucera, Leah; Tang, Yinjie

2013-10-01

132

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

133

Accurate estimation of cardinal growth temperatures of Escherichia coli from optimal dynamic experiments.  

PubMed

Prediction of the microbial growth rate as a response to changing temperatures is an important aspect in the control of food safety and food spoilage. Accurate model predictions of the microbial evolution ask for correct model structures and reliable parameter values with good statistical quality. Given the widely accepted validity of the Cardinal Temperature Model with Inflection (CTMI) [Rosso, L., Lobry, J. R., Bajard, S. and Flandrois, J. P., 1995. Convenient model to describe the combined effects of temperature and pH on microbial growth, Applied and Environmental Microbiology, 61: 610-616], this paper focuses on the accurate estimation of its four parameters (T(min), T(opt), T(max) and micro(opt)) by applying the technique of optimal experiment design for parameter estimation (OED/PE). This secondary model describes the influence of temperature on the microbial specific growth rate from the minimum to the maximum temperature for growth. Dynamic temperature profiles are optimized within two temperature regions ([15 degrees C, 43 degrees C] and [15 degrees C, 45 degrees C]), focusing on the minimization of the parameter estimation (co)variance (D-optimal design). The optimal temperature profiles are implemented in a computer controlled bioreactor, and the CTMI parameters are identified from the resulting experimental data. Approximately equal CTMI parameter values were derived irrespective of the temperature region, except for T(max). The latter could only be estimated accurately from the optimal experiments within [15 degrees C, 45 degrees C]. This observation underlines the importance of selecting the upper temperature constraint for OED/PE as close as possible to the true T(max). Cardinal temperature estimates resulting from designs within [15 degrees C, 45 degrees C] correspond with values found in literature, are characterized by a small uncertainty error and yield a good result during validation. As compared to estimates from non-optimized dynamic experiments, more reliable CTMI parameter values were obtained from the optimal experiments within [15 degrees C, 45 degrees C]. PMID:18835500

Van Derlinden, E; Bernaerts, K; Van Impe, J F

2008-07-11

134

Optimal experimental design in an epidermal growth factor receptor signalling and down-regulation model  

Microsoft Academic Search

We apply the methods of optimal experimental design to a differential equation model for epidermal growth factor receptor signalling, trafficking and down-regulation. The model incor- porates the role of a recently discovered protein complex made up of the E3 ubiquitin ligase, Cbl, the guanine exchange factor (GEF), Cool-1 (b-Pix) and the Rho family G protein Cdc42. The complex has been

F. P. Casey; D. Baird; Q. Feng; R. N. Gutenkunst; J. J. Waterfall; C. R. Myers; K. S. Brown; R. A. Cerione; J. P. Sethna

2007-01-01

135

The importance of growth and mortality costs in the evolution of the optimal life history.  

PubMed

A central assumption of life history theory is that the evolution of the component traits is determined in part by trade-offs between these traits. Whereas the existence of such trade-offs has been well demonstrated, the relative importance of these remains unclear. In this paper we use optimality theory to test the hypothesis that the trade-off between present and future fecundity induced by the costs of continued growth is a sufficient explanation for the optimal age at first reproduction, alpha, and the optimal allocation to reproduction, G, in 38 populations of perch and Arctic char. This hypothesis is rejected for both traits and we conclude that this trade-off, by itself, is an insufficient explanation for the observed values of alpha and G. Similarly, a fitness function that assumes a mortality cost to reproduction but no growth cost cannot account for the observed values of alpha. In contrast, under the assumption that fitness is maximized, the observed life histories can be accounted for by the joint action of trade-offs between growth and reproductive allocation and between mortality and reproductive allocation (Individual Juvenile Mortality model). Although the ability of the growth/mortality model to fit the data does not prove that this is the mechanism driving the evolution of the optimal age at first reproduction and allocation to reproduction, the fit does demonstrate that the hypothesis is consistent with the data and hence cannot at this time be rejected. We also examine two simpler versions of this model, one in which adult mortality is a constant proportion of juvenile mortality [Proportional Juvenile Mortality (PJM) model] and one in which the proportionality is constant within but not necessarily between species [Specific Juvenile Mortality (SSJM) model]. We find that the PJM model is unacceptable but that the SSJM model produces fits suggesting that, within the two species studied, juvenile mortality is proportional to adult mortality but the value differs between the two species. PMID:17040389

Roff, D A; Heibo, E; Vøllestad, L A

2006-11-01

136

Ronald W. Jones and Two-Sector Growth: Ramsey Optimality in the RSS and Leontief Cases  

Microsoft Academic Search

In this essay, we interpret the value-loss line, familiar in models of undiscounted optimal growth, as delineating the cone of diversification, familiar in models of international trade. This interpretation allows an embedding of the 2-sector Robinson-Solow-Srinivasan (RSS) model in the 2-sector Leontief model, and clarifies situations when the Leontief case offers additional insights into transition dynamics. The geometry underlying this

Minako Fujio; M. Ali Khan

2006-01-01

137

Optimization of vascular-targeting drugs in a computational model of tumor growth  

NASA Astrophysics Data System (ADS)

A biophysical tool is introduced that seeks to provide a theoretical basis for helping drug design teams assess the most promising drug targets and design optimal treatment strategies. The tool is grounded in a previously validated computational model of the feedback that occurs between a growing tumor and the evolving vasculature. In this paper, the model is particularly used to explore the therapeutic effectiveness of two drugs that target the tumor vasculature: angiogenesis inhibitors (AIs) and vascular disrupting agents (VDAs). Using sensitivity analyses, the impact of VDA dosing parameters is explored, as is the effects of administering a VDA with an AI. Further, a stochastic optimization scheme is utilized to identify an optimal dosing schedule for treatment with an AI and a chemotherapeutic. The treatment regimen identified can successfully halt simulated tumor growth, even after the cessation of therapy.

Gevertz, Jana

2012-04-01

138

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

139

Multifactorial optimization of endothelial cell growth using modular synthetic extracellular matrices  

PubMed Central

Extracellular matrices (ECMs) are complex materials, containing dozens of macromolecules that are assembled together, thus complicating their optimization towards applications in 3D cell culture or tissue engineering. The natural complexity of ECMs has limited cell-matrix investigations predominantly to experiments where only one matrix component is adjusted at a time, making it difficult to uncover interactions between different matrix components or to efficiently determine optimal matrix compositions for specific desired biological responses. Here we have developed modular synthetic ECMs based on peptide self-assembly whose incorporation of multiple different peptide ligands can be adjusted. The peptides can co-assemble in a wide range of combinations to form hydrogels of uniform morphology and consistent mechanical properties, but with precisely varied mixtures of peptide ligands. The modularity of this system in turn enabled multi-factorial experimental designs for investigating interactions between these ligands and for determining a multi-peptide matrix formulation that maximized endothelial cell growth. In cultures of HUVECs, we observed a previously unknown antagonistic interaction between the laminin-derived peptide YIGSR and RGDS-mediated cell attachment and growth. We also identified an optimized combination of self-assembled peptides bearing the ligands RGDS and IKVAV that led to endothelial cell growth equivalent to that on native full-length fibronectin. Both of these findings would have been challenging to uncover using more traditional one-factor-at-a-time analyses.

Jung, Jangwook P.; Moyano, Jose V.; Collier, Joel H.

2012-01-01

140

Optimization of endothelial cell growth in a murine in vitro blood-brain barrier model  

PubMed Central

In vitro cell culture models of the blood–brain barrier (BBB) are important tools used to study cellular physiology and brain disease therapeutics. Although the number of model configurations is expanding across neuroscience laboratories, it is not clear that any have been effectively optimized. A sequential screening study to identify optimal primary mouse endothelial cell parameter set points, grown alone and in combination with common model enhancements, including co-culturing with primary mouse or rat astrocytes and addition of biochemical agents in the media, was performed. A range of endothelial cell-seeding densities (1–8 × 105 cells/cm2) and astrocyte-seeding densities (2–8 × 104 cells/cm2) were studied over seven days in the system, and three distinct media-feeding strategies were compared to optimize biochemical agent exposure time. Implementation of all optimal set points increased transendothelial electrical resistance by over 200% compared to an initial model and established a suitable in vitro model for brain disease application studies. These results demonstrate the importance of optimizing cell culture growth, which is the most important parameter in creating an in vitro BBB model as it directly relates the model to the in vivo arrangement.

Wuest, Diane M; Lee, Kelvin H

2012-01-01

141

High-density spore production of Piriformospora indica, a plant growth-promoting endophyte, by optimization of nutritional and cultural parameters.  

PubMed

Piriformospora indica is an axenically cultivable root endophytic fungus which exerts plant growth promoting effects on its host plants. To enable commercial production of its spores, the medium composition and culture conditions have been optimized in a 14 L bioreactor such that they result in maximum biomass during growth phase and in maximum spore yield during subsequent sporulation phase. Maximum spore yields were obtained with modified Kaefer medium using a glucose deprivation strategy. An enhancement of 100% in overall biomass productivity (0.18 g L(-1) h(-1)) and reduction of about 70% in the time (60 h) required to achieve the maximum spore yield (9.25×10(7) spores/mL) was achieved in comparison to the original Kaefer medium. The high spore yield obtained in the present study seems to be economical for commercial production of P. indica. PMID:21095631

Kumar, Vinod; Sahai, Vikram; Bisaria, V S

2010-10-30

142

Monitoring Plasmodium falciparum Growth and Development by UV Flow Cytometry Using an Optimized Hoechst-Thiazole Orange Staining Strategy  

PubMed Central

The complex life cycle of Plasmodium falciparum (Pf) makes it difficult to limit infections and reduce the risk of severe malaria. Improved understanding of Pf blood-stage growth and development would provide new opportunities to evaluate and interfere with successful completion of the parasite’s life cycle. Cultured blood stage Pf was incubated with Hoechst 33342 (HO) and thiazole orange (TO) to stain DNA and total nucleic acids, respectively. Correlated HO and TO fluorescence emissions were then measured by flow cytometry. Complex bivariate data patterns were analyzed by manual cluster gating to quantify parasite life cycle stages. The permutations of viable staining with both reagents were tested for optimal detection of parasitized RBC (pRBC). Pf cultures were exposed to HO and TO simultaneously to achieve optimal staining of pRBC and consistent quantification of early and late stages of the replicative cycle (rings through schizonts). Staining of Pf nucleic acids allows for analysis of parasite development in the absence of fixatives, lysis, or radioactivity to enable examination of erythrocytes from parasite invasion through schizont rupture using sensitive and rapid assay procedures. Investigation of the mechanisms by which anti-malarial drugs and antibodies act against different Pf lifecycle stages will be aided by this cytometric strategy.

Grimberg, Brian T.; Erickson, John J.; Sramkoski, R. Michael; Jacobberger, James W.; Zimmerman, Peter A.

2012-01-01

143

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

ERIC Educational Resources Information Center

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

Baldridge, Mary Caufield

2010-01-01

144

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

145

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  

Microsoft Academic Search

This study introduces three growth modeling techniques: latent growth modeling (LGM), hierarchical linear modeling (HLM),\\u000a and longitudinal profile analysis via multidimensional scaling (LPAMS). It compares the multilevel growth parameter estimates\\u000a and potential predictor effects obtained using LGM, HLM, and LPAMS. The purpose of this multilevel growth analysis is to alert\\u000a applied researchers to selected analytical issues that are required for

Tacksoo Shin

2007-01-01

146

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

PubMed Central

After hundreds of generations of adaptive evolution at exponential growth, Escherichia coli grows as predicted using flux balance analysis (FBA) on genome-scale metabolic models (GEMs). However, it is not known whether the predicted pathway usage in FBA solutions is consistent with gene and protein expression in the wild-type and evolved strains. Here, we report that >98% of active reactions from FBA optimal growth solutions are supported by transcriptomic and proteomic data. Moreover, when E. coli adapts to growth rate selective pressure, the evolved strains upregulate genes within the optimal growth predictions, and downregulate genes outside of the optimal growth solutions. In addition, bottlenecks from dosage limitations of computationally predicted essential genes are overcome in the evolved strains. We also identify regulatory processes that may contribute to the development of the optimal growth phenotype in the evolved strains, such as the downregulation of known regulons and stringent response suppression. Thus, differential gene and protein expression from wild-type and adaptively evolved strains supports observed growth phenotype changes, and 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 ?

2010-01-01

147

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

2013-06-10

148

Targeting public investments by agro-ecological zone to achieve growth and poverty alleviation goals in rural India  

Microsoft Academic Search

This paper shows that improved technology and rural infrastructure have made important contributions to agricultural growth and poverty reduction in India. However, these effects have varied widely across agro-ecological zones. In the past, the government has devoted more resources to irrigated areas, and this has led to significant production growth and poverty reduction in those areas. However, as investments in

Shenngen Fan; Peter Hazell; T. Haque

2000-01-01

149

Bacillus subtilis endospores at high purity and recovery yields: optimization of growth conditions and purification method.  

PubMed

Bacillus subtilis endospores have applications in different fields including their use as probiotics and antigen delivery vectors. Such specialized applications frequently require highly purified spore preparations. Nonetheless, quantitative data regarding both yields and purity of B. subtilis endospores after application of different growth conditions and purification methods are scarce or poorly reported. In the present study, we conducted several quantitative and qualitative analyses of growth conditions and purification procedures aiming generation of purified B. subtilis spores. Based on two growth media and different incubations conditions, sporulation frequencies up to 74.2 % and spore concentrations up to 7 × 10(9) spores/ml were achieved. Application of a simplified spore isolation method, in which samples were incubated with lysozyme and a detergent, resulted in preparations with highly purified spores at the highest yields. The present study represents, therefore, an important contribution for those working with B. subtilis endospores for different biotechnological purposes. PMID:23183956

Tavares, Milene B; Souza, Renata D; Luiz, Wilson B; Cavalcante, Rafael C M; Casaroli, Caroline; Martins, Eduardo G; Ferreira, Rita C C; Ferreira, Luís C S

2012-11-27

150

Optimal concentration of ammonium ion in a minimal synthetic medium for the growth of Candida albicans.  

PubMed

Candida albicans strain B 311-10 with and without starvation was cultivated in the minimal synthetic medium of Shepherd et al., modified without biotin, amino acids, low glucose concentration and with decreasing amounts of (NH4)2SO4, to determine the optimal growth requirement for this strain. All the experiments were carried out under sterile conditions at 25 degrees C in a thermostat with initial O.D.s (675 nm) of 0.500 and 0.100. Cell growth was generally monitored everyday for six days with a spectrophotometer by determining the absorbance of the cultures at 675 nm. All the experiments were repeated three times and a statistical analysis of the data with a probability of 99% and 1% of error was performed to confirm the validity of the results. Best growth was obtained with starved cells at an initial O.D. of 0.100 and with a 0.1 g/L concentration of (NH4)2SO4. At this concentration, the growth of C. albicans B 311-10 was best between the first and the fourth day with the maximum at the third day. With (NH4)2SO4 concentrations of 0.05 and 0.5 g/L, cell growth was the same. PMID:2067560

Vidotto, V; Ochoa, L G; Cortes, J M; Bruatto, M

1991-03-01

151

Optimized growth and dielectric properties of barium titanate thin films on polycrystalline Ni foils  

NASA Astrophysics Data System (ADS)

Barium titanate (BTO) thin films were deposited on polycrystalline Ni foils by using the polymer assisted deposition (PAD) technique. The growth conditions including ambient and annealing temperatures were carefully optimized based on thermal dynamic analysis to control the oxidation processing and interdiffusion. Crystal structures, surface morphologies, and dielectric performance were examined and compared for BTO thin films annealed under different temperatures. Correlations between the fabrication conditions, microstructures, and dielectric properties were discussed. BTO thin films fabricated under the optimized conditions show good crystalline structure and promising dielectric properties with inr ~ 400 and tan ? < 0.025 at 100 kHz. The data demonstrate that BTO films grown on polycrystalline Ni substrates by PAD are promising in device applications.

Liang, Wei-Zheng; Ji, Yan-Da; Nan, Tian-Xiang; Huang, Jiang; Zeng, Hui-Zhong; Du, Hui; Chen, Chong-Lin; Lin, Yuan

2012-06-01

152

Optimal experimental design in an epidermal growth factor receptor signalling and down-regulation model.  

PubMed

We apply the methods of optimal experimental design to a differential equation model for epidermal growth factor receptor signalling, trafficking and down-regulation. The model incorporates the role of a recently discovered protein complex made up of the E3 ubiquitin ligase, Cbl, the guanine exchange factor (GEF), Cool-1 (beta -Pix) and the Rho family G protein Cdc42. The complex has been suggested to be important in disrupting receptor down-regulation. We demonstrate that the model interactions can accurately reproduce the experimental observations, that they can be used to make predictions with accompanying uncertainties, and that we can apply ideas of optimal experimental design to suggest new experiments that reduce the uncertainty on unmeasurable components of the system. PMID:17591178

Casey, F P; Baird, D; Feng, Q; Gutenkunst, R N; Waterfall, J J; Myers, C R; Brown, K S; Cerione, R A; Sethna, J P

2007-05-01

153

Academic achievement of homeless and highly mobile children in an urban school district: Longitudinal evidence on risk, growth, and resilience  

Microsoft Academic Search

Abstract Longitudinalgrowthtrajectoriesofreadingandmathachievementwerestudiedinfourprimaryschoolgradecohorts(GCs)of a large urban district to examine academic risk and resilience in homeless and highly mobile (H\\/HM) students. Initial achievement was assessed when student cohorts were in the second, third, fourth, and fifth grades, and again 12 and 18 monthslater.AchievementtrajectoriesofH\\/HMstudentswerecomparedtolow-incomebutnonmobilestudentsandallother tested students in the district, controlling for four well-established covariates of achievement: sex, ethnicity, attendance, and English language skills.

Jelena Obradovi?; Jeffrey D. Long; J. J. Cutuli; Chi-Keung Chan; Elizabeth Hinz; David Heistad; Ann S. Masten

2009-01-01

154

Agro-Exports and the Rural Resource Poor in Latin America: Policy Options for Achieving Broadly Based Growth  

Microsoft Academic Search

Concentrating on fundamental sector-level impacts that shape the nature of agro-export growth, this paper indicates how intrahousehold impacts fit into the analysis. Section 1 is introductory. Section 2 puts forward the conceptual framework needed to understand sectoral impacts of agro-export growth on the rural resource poor, impacts that can be divided into a small-farm adoption effect, a land-access effect, and

Michael R. Carter; Bradford L. Barham; Dina Mesbah; Denise Stanley

1995-01-01

155

Optical spectroscopy and optimal crystal growth of some Cr4+-doped garnets  

NASA Astrophysics Data System (ADS)

This paper describes the growth of single crystals of Cr4+ -doped Y3 Ga5 O12 (YGG) and Y3 Al5 O12 (YAG). Control of melt composition and post-growth annealing yields material that contains optimal concentrations of Cr4+ ions in distorted tetrahedral sites normally occupied by Ga3+ ions in YGG and Al3+ ions in YAG. Both Cr4+ -doped garnets exhibit strong visible and near-infrared absorption bands with peak cross sections of order 10-18 -10-19 cm2 and emit into vibronically broadened but weakly allowed 3 B2 (3 T2 )icons/Journals/Common/to" ALT="to" ALIGN="TOP"/> 3 B1 (3 A2 ) transitions. Nonradiative decay is more efficient in YGG than in YAG as a consequence of the slightly reduced energy gap against radiative decay in the Ga-based garnet.

Henderson, B.; Gallagher, H. G.; Han, T. P. J.; Scott, M. A.

2000-02-01

156

AlGaN based Tunable Hyperspectral Detector: Growth and Device Structure Optimization  

NASA Astrophysics Data System (ADS)

We report on fabrication and growth optimization of an AlGaN/GaN based tunable hyperspectral detector. III-Nitride based detectors possess the potential to detect a large portion, from UV to IR, of the electromagnetic spectrum. Control over the detection wavelength with applied bias across an AlInGaN heterostructure can provide a compact tunable hyperspectral detector eliminating use of filters and gratings which make current tunable detectors bulky. Challenges involved in the development of the device include controlled deposition and characterization of thin layers of AlxGa1-xN with Al composition varying from 0% to 100% and back to 0%. Performance of such detector is greatly affected by the thickness and quality of the thin heteroepitaxially grown layers which control the dark current and operating voltage of the device. We will present the effect of growth conditions and heterostructure parameters such as composition and thickness on the device performance.

Tripathi, Neeraj; Grandusky, James R.; Jindal, Vibhu; Shahedipour-Sandvik, Fatemeh; Bell, L. Douglas

2007-03-01

157

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

158

Super-optimal CO2 reduces wheat yield in growth chamber and greenhouse environments  

NASA Astrophysics Data System (ADS)

Seven growth chamber trials (six replicate trials using 0.035, 0.12, and 0.25 % CO_2 in air and one trial using 0.12, 0.80, and 2.0% CO_2 in air) and three replicate greenhouse trials (0.035, 0.10, 0.18, 0.26, 0.50, and 1.0% CO_2 in air) compare the effects of super-optimal CO_2 on the seed yield, harvest index, and vegetative growth rate of wheat (Triticum aestivum L. cvs. USU-Apogee and Veery-10). Plants in the growth chamber trials were grown hydroponically under fluorescent lamps, while the greenhouse trials were grown under sunlight and high pressure sodium lamps and in soilless media. Plants in the greenhouse trials responded similarly to those in the growth chamber trials; maximum yields occurred near 0.10 and 0.12 % CO_2 and decreased significantly thereafter. This research indicates that the toxic effects of elevated CO_2 are not specific to only one environment and has important implications for the design of bio-regenerative life support systems in space, and for the future of terrestrial agriculture.

Grotenhuis, T.; Reuveni, J.; Bugbee, B.

1997-01-01

159

The Role of Maternal Smoking in Effect of Fetal Growth Restriction on Poor Scholastic Achievement in Elementary School  

PubMed Central

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

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

2012-01-01

160

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

161

Optimal growth of Ge-rich dots on Si(001) substrates with hexagonal packed pit patterns  

NASA Astrophysics Data System (ADS)

This paper reports a three-step method to fabricate hexagonal ordered Ge dots on Si with controllable size and spacing. After the introduction of a thin Si dioxide layer on the Si substrate, porous alumina turns out to be a good candidate for pattern transferring, which is rapid and simple to implement. A density-temperature relation for Ge dots has been discovered in this work; the Arrhenius relation with a slope of 0.33 is proved to be applicable for predicting the optimal temperature for a certain density of patterns. Different widths of pits are also studied to discover the dependence of the dot distribution on the pit morphology. The optimal pit width for ordered Ge dots is around 30 nm, while four aligned Ge dots can be achieved in a 70 nm pit. Extremely high Ge content (>0.92) in capped Ge dots is discovered by Raman characterization because the high density of pits leads to a low enough optimal temperature of 430?°C. The photoluminescence spectra of the capped dots also prove the high purity and quality of the Ge dots.

Huangfu, Yourui; Zhan, Wenbo; Hong, Xia; Fang, Xu; Ding, Guqiao; Ye, Hui

2013-01-01

162

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

163

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

ERIC Educational Resources Information Center

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

Ready, Douglas; Tindal, Gerald

2006-01-01

164

Math and Science Achievement in English Language Learners: Multivariate Latent Growth Modeling of Predictors, Mediators, and Moderators  

ERIC Educational Resources Information Center

The effectiveness of various strategies for educating the growing U.S. population of English language learners (ELLs) has attracted a great deal of controversy. Bilingual education theory posits that retention and continued development of native language (L1) skills facilitate academic achievement through two mediating mechanisms. First, L1…

Guglielmi, R. Sergio

2012-01-01

165

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

ERIC Educational Resources Information Center

The present study on the influence of parental involvement on students' academic achievement overcame limitations in current research by including simultaneous considerations of multidimensional, longitudinal, mediational, and ethnic factors. Results indicated (a) significant ethnic differences in the direct effects of parental involvement on…

Hong, Sehee; Ho, Hsiu-Zu

2005-01-01

166

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

ERIC Educational Resources Information Center

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

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

2013-01-01

167

Simulation Optimization of the Heat Transfer Conditions in Hfcvd Diamond Film Growth Inside Holes  

NASA Astrophysics Data System (ADS)

Finite volume method (FVM) is adopted in the present investigation to simulate the temperature and reactant gas velocity distributions in hot filament chemical vapor deposition (HFCVD) diamond film growth inside holes, using a detailed 3D computational model well in accordance with the actual reactor. The influences of the heat transfer characteristic of the substrate and the auxiliary heat transfer conditions are firstly studied by control variable method (CVM), including the thermal conductivity of the substrate k, the size of the red bronze support block V(x × y × z), the cooling water flux Qw, the reactant gas flux Qg, the arrangement of the gas outlets Aout and the emissivities of the different solid surfaces ?. Thereafter, the substrate temperature data measured in the actual HFCVD reactor with three chosen groups of parameters are compared with those obtained from the simulations, presenting similar trends and small deviations less than 5%. Moreover, the auxiliary heat transfer conditions are optimized for both the WC-Co and SiC substrates based on the simulation and measurement results, and corresponding deposition parameters are also determined. Furthermore, HFCVD diamond films are deposited on the inner surfaces of both the substrates under the optimized conditions. The characterization results show that high-quality diamond films with uniform thickness and fine-faceted crystals are obtained, indicating that this optimization method focusing on the heat transfer conditions is feasible and correct.

Wang, Xinchang; Zhang, Jianguo; Zhang, Tao; Shen, Bin; Sun, Fanghong

2013-08-01

168

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

2013-09-06

169

Cyclic autotrophic\\/heterotrophic cultivation of photosynthetic cells: A method of achieving continuous cell growth under light\\/dark cycles  

Microsoft Academic Search

Due to diurnal changes in light intensity and light\\/dark cycles, the number of hours in a day when the intensity of solar light energy is high enough to support photosynthetic cell growth can be very short depending on the location and season. The night biomass loss greatly reduces the productivities of photobioreactors. As a solution to this problem, cyclic autotrophic\\/heterotrophic

James C. Ogbonna; Hideo Tanaka

1998-01-01

170

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

Microsoft Academic Search

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

David Shropshire

2009-01-01

171

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

172

Aconitase B is required for optimal growth of Xanthomonas campestris pv. vesicatoria in pepper plants.  

PubMed

The aerobic plant pathogenic bacterium Xanthomonas campestris pv. vesicatoria (Xcv) colonizes the intercellular spaces of pepper and tomato. One enzyme that might contribute to the successful proliferation of Xcv in the host is the iron-sulfur protein aconitase, which catalyzes the conversion of citrate to isocitrate in the tricarboxylic acid (TCA) cycle and might also sense reactive oxygen species (ROS) and changes in cellular iron levels. Xcv contains three putative aconitases, two of which, acnA and acnB, are encoded by a single chromosomal locus. The focus of this study is aconitase B (AcnB). acnB is co-transcribed with two genes, XCV1925 and XCV1926, encoding putative nucleic acid-binding proteins. In vitro growth of acnB mutants was like wild type, whereas in planta growth and symptom formation in pepper plants were impaired. While acnA, XCV1925 or XCV1926 mutants showed a wild-type phenotype with respect to bacterial growth and in planta symptom formation, proliferation of the acnB mutant in susceptible pepper plants was significantly impaired. Furthermore, the deletion of acnB led to reduced HR induction in resistant pepper plants and an increased susceptibility to the superoxide-generating compound menadione. As AcnB complemented the growth deficiency of an Escherichia coli aconitase mutant, it is likely to be an active aconitase. We therefore propose that optimal growth and survival of Xcv in pepper plants depends on AcnB, which might be required for the utilization of citrate as carbon source and could also help protect the bacterium against oxidative stress. PMID:22493725

Kirchberg, Janine; Büttner, Daniela; Thiemer, Barbara; Sawers, R Gary

2012-04-06

173

Aconitase B Is Required for Optimal Growth of Xanthomonas campestris pv. vesicatoria in Pepper Plants  

PubMed Central

The aerobic plant pathogenic bacterium Xanthomonas campestris pv. vesicatoria (Xcv) colonizes the intercellular spaces of pepper and tomato. One enzyme that might contribute to the successful proliferation of Xcv in the host is the iron-sulfur protein aconitase, which catalyzes the conversion of citrate to isocitrate in the tricarboxylic acid (TCA) cycle and might also sense reactive oxygen species (ROS) and changes in cellular iron levels. Xcv contains three putative aconitases, two of which, acnA and acnB, are encoded by a single chromosomal locus. The focus of this study is aconitase B (AcnB). acnB is co-transcribed with two genes, XCV1925 and XCV1926, encoding putative nucleic acid-binding proteins. In vitro growth of acnB mutants was like wild type, whereas in planta growth and symptom formation in pepper plants were impaired. While acnA, XCV1925 or XCV1926 mutants showed a wild-type phenotype with respect to bacterial growth and in planta symptom formation, proliferation of the acnB mutant in susceptible pepper plants was significantly impaired. Furthermore, the deletion of acnB led to reduced HR induction in resistant pepper plants and an increased susceptibility to the superoxide-generating compound menadione. As AcnB complemented the growth deficiency of an Escherichia coli aconitase mutant, it is likely to be an active aconitase. We therefore propose that optimal growth and survival of Xcv in pepper plants depends on AcnB, which might be required for the utilization of citrate as carbon source and could also help protect the bacterium against oxidative stress.

Kirchberg, Janine; Buttner, Daniela; Thiemer, Barbara; Sawers, R. Gary

2012-01-01

174

Optimal Energies for Ion-Assisted Growth of IVA Thin Films  

NASA Astrophysics Data System (ADS)

Based on a modified interaction potential and experimental results, an extensive study of ion-energy-correlative thin film growth is presented, As a result, an analytical model for ion energy dissipation into top surface layers is proposed. The proposed model extends previously published models and includes analytical expressions for lattice damage by atomic displacement in surface and subsurface layers. Theoretical calculation indicated that there were three distinctive ion energy regimes within which the different processes occur to the condensed adatoms. The medium energy region (in tens of eV) is a favorite "energy window" from which the pre-deposited atoms or atomic clusters on the substrate can be stimulated further to be rearranged by absorbing the effective energy from an energetic ion beam, leading to uniform film growth. However, over the energy region, the ion can penetrate deeply into the film, and more damage will be caused in the subsurface layer or bulk in this case, which results in the growth of poor-quality or amorphous films. When the ion energy is lower than the "energy window", there is no driving effect for adatoms in both surface and subsurface layers. The molecular dynamic simulations and experimental results have verified the validity of the proposed analytical model and optimal ion energy regimes.

Ma, Z. Q.

175

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

NASA Astrophysics Data System (ADS)

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

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

2011-07-01

176

Screening and optimization of indole-3-acetic acid production and phosphate solubilization from rhizobacteria aimed at improving plant growth.  

PubMed

A total of 216 bacterial strains were isolated from rice rhizospheric soils in Northern Thailand. The bacterial strains were initially tested for solubilization of inorganic phosphate, indole acetic acid (IAA) production, selected strains were then tested for optimized conditions for IAA production and whether these caused stimulatory effects on bean and maize seedling growth. It was found that all strains had solubilized inorganic phosphate (P), but only 18.05% produced IAA. The best IAA producer was identified by biochemical testing and 16S rDNA sequence analysis as Klebsiella SN 1.1. In addition to being the best IAA producer, this strain was a high P-solubilizer and produced the highest amount of IAA (291.97 ± 0.19 ppm) in culture media supplemented with L-tryptophan. The maximum production of IAA was achieved after 9 days of incubation. The culture requirements were optimized for maximum IAA production. The tested of IAA production by selected isolates was studied in a medium with 0, 0.1, 0.2, 0.5, 0.7, and 0.9% (v/v) L-tryptophan. Low levels (12.6 ppm) of IAA production was recorded without tryptophan addition. Production of IAA in Klebsiella SN 1.1 increased with an increase to 0.2% (v/v) tryptophan concentration. The production of IAA was further confirmed by extraction of crude IAA from this isolate and subsequent Thin Layer Chromatography (TLC) analysis. A specific spot from the extracted IAA production was found to correspond with a standard spot of IAA with the same R (f) value. The Klebsiella strain SN 1.1 also demonstrated stimulatory effects on bean seedlings in vivo. PMID:20552360

Chaiharn, Mathurot; Lumyong, Saisamorn

2010-06-16

177

High quality p-type Ag-doped ZnO thin films achieved under elevated growth temperatures.  

PubMed

By correlating the effects of substrate temperature, oxygen pressure and laser energy on the electrical and microstructural properties of Ag-doped ZnO films grown on a sapphire (0001) substrate, p-type conductivity is achieved under various substrate temperatures in the wide range of 250-750?°C. All of the samples were deposited by pulsed-laser deposition under various designed conditions. Hall measurements indicate that the best conductivity is achieved in Ag-ZnO films under a substrate temperature of 500?°C, a partial oxygen pressure of 250-300 mTorr and laser energy between 330 and 345 mJ. The hole-carrier concentration is 2.29 × 10(18) cm(-3), the resistivity is 0.9 ? cm and the mobility is 3.03 cm(2) V(-1) s(-1). Transmission-electron microscopy (TEM) studies on the p-type films reveal similar microstructural properties to one another, but different properties to that of the n-type films deposited at the same temperatures with different deposition parameters. PMID:22417979

Myers, Michelle A; Lee, Joon Hwan; Bi, Zhenxing; Wang, Haiyan

2012-03-15

178

Optimization of culture conditions to obtain maximal growth of penicillin-resistant Streptococcus pneumoniae  

PubMed Central

Background Streptococcus pneumoniae, particularly penicillin-resistant strains (PRSP), constitute one of the most important causes of serious infections worldwide. It is a fastidious microorganism with exquisite nutritional and environmental requirements to grow, a characteristic that prevents the development of useful animal models to study the biology of the microorganism. This study was designed to determine optimal conditions for culture and growth of PRSP. Results We developed a simple and reproducible method for culture of diverse strains of PRSP representing several invasive serotypes of clinical and epidemiological importance in Colombia. Application of this 3-step culture protocol consistently produced more than 9 log10 CFU/ml of viable cells in the middle part of the logarithmic phase of their growth curve. Conclusion A controlled inoculum size grown in 3 successive steps in supplemented agar and broth under 5% CO2 atmosphere, with pH adjustment and specific incubation times, allowed production of great numbers of PRSP without untimely activation of autolysis mechanisms.

Restrepo, Andrea V; Salazar, Beatriz E; Agudelo, Maria; Rodriguez, Carlos A; Zuluaga, Andres F; Vesga, Omar

2005-01-01

179

Optimization of submerged culture conditions for mycelial growth and exo-biopolymer production by Paecilomyces tenuipes C240  

Microsoft Academic Search

This paper is concerned with optimization of submerged culture conditions for mycelial growth and exo-biopolymer production by Paecilomyces tenuipes C240 by one-factor-at-a-time and orthogonal matrix methods. The one-factor-at-a-time method was adopted to investigate the effects of medium components (i.e. carbon, nitrogen, and mineral sources) and environmental factors (i.e. initial pH and temperature) on mycelial growth and exo-biopolymer production. Among these

Chun-Ping Xu; Sang-Woo Kim; Hye-Jin Hwang; Jang-Won Choi; Jong-Won Yun

2003-01-01

180

Growth and ligninolytic system production dynamics of the Phanerochaete chrysosporium fungus A modelling and optimization approach.  

PubMed

The well-documented ability to degrade lignin and a variety of complex chemicals showed by the white-rot fungus Phanerochaete chrysosporium has made it the subject of many studies in areas of environmental concern, including pulp bioleaching and bioremediation technologies. However, until now, most of the work in this field has been focused on the ligninolytic sub-system but, due to the great complexity of the involved processes, less progress has been made in understanding the biochemical regulatory structure that could explain growth dynamics, the substrate utilization and the ligninolytic system production itself. In this work we want to tackle this problem from the perspectives and approaches of systems biology, which have been shown to be effective in the case of complex systems. We will use a top-down approach to the construction of this model aiming to identify the cellular sub-systems that play a major role in the whole process. We have investigated growth dynamics, substrate consumption and lignin peroxidase production of the P. chrysosporium wild type under a set of definite culture conditions. Based on data gathered from different authors and in our own experimental determinations, we built a model using a GMA power-law representation, which was used as platform to make predictive simulations. Thereby, we could assess the consistency of some current assumptions about the regulatory structure of the overall process. The model parameters were estimated from a time series experimental measurements by means of an algorithm previously adapted and optimized for power-law models. The model was subsequently checked for quality by comparing its predictions with the experimental behavior observed in new, different experimental settings and through perturbation analysis aimed to test the robustness of the model. Hence, the model showed to be able to predict the dynamics of two critical variables such as biomass and lignin peroxidase activity when in conditions of nutrient deprivation and after pulses of veratryl alcohol. Moreover, it successfully predicts the evolution of the variables during both, the active growth phase and after the deprivation shock. The close agreement between the predicted and observed behavior and the advanced understanding of its kinetic structure and regulatory features provides the necessary background for the design of a biotechnological set-up designed for the continuous production of the ligninolityc system and its optimization. PMID:18694789

Hormiga, J A; Vera, J; Frías, I; Torres Darias, N V

2008-07-22

181

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

182

Optimal \\  

Microsoft Academic Search

This article describes optimal bankruptcy laws in a framework with asymmetric information. The key idea is that the financial distress of a firm is not observed by its lenders for quite a while. As early rescues are much cheaper than late rescues, it may pay if the creditors are forgiving in bankruptcy, thereby inducing the revelation of difficulties as early

Paul Povel

1999-01-01

183

Towards a monolithically integrated III–V laser on silicon: optimization of multi-quantum well growth on InP on Si  

NASA Astrophysics Data System (ADS)

High-quality InGaAsP/InP multi-quantum wells (MQWs) on the isolated areas of indium phosphide on silicon necessary for realizing a monolithically integrated silicon laser is achieved. Indium phosphide layer on silicon, the pre-requisite for the growth of quantum wells is achieved via nano-epitaxial lateral overgrowth (NELOG) technique from a defective seed indium phosphide layer on silicon. This technique makes use of epitaxial lateral overgrowth (ELOG) from closely spaced (1 µm) e-beam lithography-patterned nano-sized openings (?300?nm) by low-pressure hydride vapor phase epitaxy. A silicon dioxide mask with carefully designed opening patterns and thickness with respect to the opening width is used to block the defects propagating from the indium phosphide seed layer by the so-called necking effect. Growth conditions are optimized to obtain smooth surface morphology even after coalescence of laterally grown indium phosphide from adjacent openings. Surface morphology and optical properties of the NELOG indium phosphide layer are studied using atomic force microscopy, cathodoluminescence and room temperature µ-photoluminescence (µ-PL) measurements. Metal organic vapor phase epitaxial growth of InGaAsP/InP MQWs on the NELOG indium phosphide is conducted. The mask patterns to avoid loading effect that can cause excessive well/barrier thickness and composition change with respect to the targeted values is optimized. Cross-sectional transmission electron microscope studies show that the coalesced NELOG InP on Si is defect-free. PL measurement results indicate the good material quality of the grown MQWs. Microdisk (MD) cavities are fabricated from the MQWs on ELOG layer. PL spectra reveal the existence of resonant modes arising out of these MD cavities. A mode solver using finite difference method indicates the pertinent steps that should be adopted to realize lasing.

Kataria, H.; Junesand, C.; Wang, Z.; Metaferia, W.; Sun, Y. T.; Lourdudoss, S.; Patriarche, G.; Bazin, A.; Raineri, F.; Mages, P.; Julian, N.; Bowers, J. E.

2013-09-01

184

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

PubMed

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

2009-08-01

185

Development and Optimization of High-Throughput Methods To Measure Plasmodium falciparum-Specific Growth Inhibitory Antibodies  

Microsoft Academic Search

Antibodies that inhibit replication of Plasmodium falciparum in erythrocytes are thought to be important both in acquired immunity to malaria and as mediators of immunity generated by candidate blood-stage vaccines. However, several constraints have limited the study of these functional antibodies in population studies and vaccine trials. We report the development and optimization of high-throughput growth inhibition assays with improved

Kristina E. M. Persson; Chee T. Lee; Kevin Marsh; James G. Beeson

186

Development and Optimization of High-Throughput Methods To Measure Plasmodium falciparum-Specific Growth Inhibitory Antibodies  

Microsoft Academic Search

Antibodies that inhibit replication of Plasmodium falciparum in erythrocytes are thought to be important both in acquired immunity to malaria and as mediators of immunity generated by candidate blood-stage vaccines. However, several constraints have limited the study of these functional antibodies in population studies and vaccine trials. We report the development and optimization of high-throughput growth inhibition assays with improved

Kristina E. M. Persson; Chee T. Lee; Kevin Marsh; James G. Beeson

2006-01-01

187

Oxygen levels that optimize TSC culture are identified by maximizing growth rates and minimizing stress.  

PubMed

Accumulating data suggest that 20% O(2) causes human and mouse placental trophoblast stem cell (TSC) differentiation and suppresses proliferation. We tested the hypotheses that phosphorylated stress-activated protein kinase (pSAPK) levels report the optimal O(2) level for TSC culture, and that pSAPK responds to contradictory signals. We tested the dose range of 0-20% O(2) (0, 0.5, 2, and 20%) on five effects in cultured TSC. The results showed 1) TSC accumulation rates were highest at 2% O(2), lower at 20% and lowest at 0-0.5%; 2) pSAPK protein levels were lowest at 2% O(2), higher at 20%, and highest at 0-0.5%; 3) Cleaved caspase 3, an apoptosis marker, increased at 0.5% O(2), and was highest at 0% O(2); 4) Three markers for multipotency were highest at 2 and 20% and significantly decreased at 0.5%-0%; 5) In contrast three differentiation markers were lowest at 2% and highest at 0.5%-0%. Thus, 2% O(2) is the optimum as defined by lowest pSAPK and differentiation markers and highest growth rate and multipotency markers, without appreciable apoptosis. In addition, two lines of evidence suggest that fibroblast growth factor (FGF)4 does not directly activate SAPK. SAPK activity increases transiently with FGF4 removal at 2% O(2), but SAPK activity decreases when O(2) is switched from 20% to 2% with FGF4 present. Thus, SAPK is activated by contradictory signals, but activity decreases when either signal is removed. Taken together, the findings suggest that pSAPK senses suboptimal signals during TSC culture and probably in vivo. PMID:21511332

Zhou, S; Xie, Y; Puscheck, E E; Rappolee, D A

2011-04-21

188

Oxygen levels that optimize TSC culture are identified by maximizing growth rates and minimizing stress  

PubMed Central

Accumulating data suggest that 20% O2 causes human and mouse placental trophoblast stem cell (TSC) differentiation and suppresses proliferation. We tested the hypotheses that phosphorylated stress-activated protein kinase (pSAPK) levels report the optimal O2 level for TSC culture, and that pSAPK responds to contradictory signals. We tested the dose range of 0–20% O2 (0, 0.5, 2, and 20%) on five effects in cultured TSC. The results showed 1) TSC accumulation rates were highest at 2% O2, lower at 20% and lowest at 0–0.5%; 2) pSAPK protein levels were lowest at 2% O2, higher at 20%, and highest at 0–0.5%; 3) Cleaved caspase 3, an apoptosis marker, increased at 0.5% O2, and was highest at 0% O2. 4) Three markers for multipotency were highest at 2 and 20% and significantly decreased at 0.5%–0%. 5) In contrast three differentiation markers were lowest at 2% and highest at 0.5%–0%. Thus, 2% O2 is the optimum as defined by lowest pSAPK and differentiation markers and highest growth rate and multipotency markers, without appreciable apoptosis. In addition, two lines of evidence suggest that fibroblast growth factor (FGF)4 does not directly activate SAPK. SAPK activity increases transiently with FGF4 removal at 2% O2, but SAPK activity decreases when O2 is switched from 20% to 2% with FGF4 present. Thus, SAPK is activated by contradictory signals, but activity decreases when either signal is removed. Taken together, the findings suggest that pSAPK senses suboptimal signals during TSC culture and probably in vivo.

Zhou, S; Xie, Y; Puscheck, EE; Rappolee, DA

2011-01-01

189

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.

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

2013-01-01

190

Modeling dynamic urban growth using hybrid cellular automata and particle swarm optimization  

NASA Astrophysics Data System (ADS)

Conventional raster-based cellular automata (CA) confront many difficulties because of cell size and neighborhood sensitivity. Alternatively, vector CA-based models are very complex and difficult to implement. We present a hybrid cellular automata (HCA) model as a combination of cellular structure and vector concept. The space is still defined by a set of cells, but rasterized spatial objects are also utilized in the structure of transition rules. Particle swarm optimization (PSO) is also used to calculate the urbanization probability of cells based on their distance from the development parameters. The proposed model is applied to Landsat satellite imagery of the city of Tehran, Iran with 28.5-m spatial resolution to simulate the urban growth from 1988 to 2010. Statistical comparison of the ground truth and the simulated image using a kappa coefficient shows an accuracy of 83.42% in comparison to the 81.13% accuracy for the conventional Geo-CA model. Moreover, decreasing the spatial resolution by a factor of one-fourth has reduced the accuracy of the HCA and Geo-CA models by 1.19% and 3.04%, respectively, which shows the lower scale sensitivity of the proposed model. The HCA model is developed to have the simplicity of cellular structure together with optimum features of vector models.

Rabbani, Amirhosein; Aghababaee, Hossein; Rajabi, Mohammad A.

2012-01-01

191

Differential stability of TATA box binding proteins from archaea with different optimal growth temperatures  

NASA Astrophysics Data System (ADS)

The TATA box binding protein (TBP) is involved in promoter recognition, the first step of transcription initiation. TBP is universally conserved and essential in archaea and eukaryotes. In archaea, TBPs have to be stable and to function in species that cover an extremely wide range of optimal growth temperatures (OGTs), from below 0 °C to more than 100 °C. Thus, the archaeal TBP family is ideally suited to study the evolutionary adaptation of proteins to an extremely wide range of temperatures. We characterized the thermostability of one mesophilic and one thermophilic TBP by infrared spectroscopy. Transition temperatures ( Tms) of thermal unfolding have been determined using TBPs from Methanosarcina mazei (OGT 37 °C) and from Methanothermobacter thermautotrophicus (OGT 65 °C). Furthermore, the influence of protein and salt concentration on thermostability has been characterized. Together with previous studies, our results reveal that the Tms of archaeal TBPs are closely correlated with the OGTs of the respective species. Noteworthy, this is also true for the TBP from M. mazei representing the first characterized TBP from a mesophilic archaeon. In contrast, the only characterized eukaryotic TBP of the mesophilic plant Arabidopsis thaliana has a Tm more than 40 °C above the OGT.

Kopitz, Annette; Soppa, Jörg; Krejtschi, Carsten; Hauser, Karin

2009-09-01

192

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

193

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

NASA Astrophysics Data System (ADS)

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 10-8 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 Co40Fe40B20 and 1 Ta/20 conetic (Ni77Fe14Cu5Mo4)/1.5 Co40Fe40B20 (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; Lee, Chan-Gyu; Shapiro, Alexander J.; Egelhoff, William F.; Vaudin, Mark D.; Ruglovsky, Jennifer L.; Mallett, Jonathan; Pong, Philip W. T.

2008-04-01

194

Exploring How Technology Growth Limits Impact Optimal Carbon dioxide Mitigation Pathways  

EPA Science Inventory

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

195

CdSe/ZnSe Quantum Dots Formed by Low Temperature Epitaxy and In-Situ Annealing: Properties and Growth Optimization  

NASA Astrophysics Data System (ADS)

The formation of CdSe/ZnSe quantum dots by a method combining a low temperature MBE growth of a CdSe layer and its subsequent in-situ annealing at temperatures between 280-340ºC has been studied. The thermal treatment results in a re-organization of the surface from a nearly two-dimensional layer to an ensemble of three-dimensional dot-like features. In this work we optimized the different growth and annealing parameters of this process and compared the properties of the resultant dots with those of dots grown by conventional MBE at 300ºC. It is demonstrated that the luminescence properties of the dots for both growth techniques are comparable but the areal density achieved by the in-situ annealing technique is an order of magnitude lower. From high resolution X-ray diffraction results, it could be established that no desorption takes place despite significantly long annealing duration. Beyond a nominal coverage of 3.5 ML CdSe, stacking faults are generated, leading to a gradual decrease in luminescence intensities and an overlap of pendellösung fringes in X-ray diffractograms.

Mahapatra, S.; Schumacher, C.; Kiessling, T.; Astakhov, G. V.; Bass, U.; Ossau, W.; Geurts, J.; Brunner, K.

2006-11-01

196

Season-dependent dynamics of nonlinear optimal error growth and El Niño-Southern Oscillation predictability in a theoretical model  

Microsoft Academic Search

Most state-of-the-art climate models have difficulty in the prediction of El Niño-Southern Oscillation (ENSO) starting from preboreal spring seasons. The causes of this spring predictability barrier (SPB) remain elusive. With a theoretical ENSO system model, we investigate this controversial issue by tracing the evolution of conditional nonlinear optimal perturbation (CNOP) and by analyzing the behavior of initial error growth. The

Mu Mu; Wansuo Duan; Bin Wang

2007-01-01

197

Appraising Reading Achievement.  

ERIC Educational Resources Information Center

To determine quality sequence in pupil progress, evaluation approaches need to be used which guide the teacher to assist learners to attain optimally. Teachers must use a variety of procedures to appraise student achievement in reading, because no one approach is adequate. Appraisal approaches might include: (1) observation and subsequent…

Ediger, Marlow

198

Optimal and adaptive testing for software reliability assessment  

Microsoft Academic Search

Optimal software testing is concerned with how to test software such that the underlying testing goal is achieved in an optimal manner. Our previous work shows that the optimal testing problem for software reliability growth can be treated as closed-loop or feedback control problem, where the software under test serves as a controlled object and the software testing strategy serves

Kai-Yuan Caia; Yong-Chao Li; Ke Liu

199

Optimal growth windows of multiferroic BiFeO 3 films and characteristics of ferroelectric domain structures  

Microsoft Academic Search

Multiferroic BiFeO3 films of smooth surface and fully-saturated ferroelectric hysteresis loops have been grown by RF magnetron sputtering. The (001)-oriented epitaxial films showed a large remanent polarisation of 61 µC\\/cm2. A strategy to grow BiFeO3 films of good ferroelectric property was demonstrated, that was using fast growth rate to achieve accurate stoichiometry for the BiFeO3 phase and at the same time

Xiaoding Qi; Po-Chou Tsai; Yi-Chun Chen; Qi-Rui Lin; Jung-Chun-Andrew Huang; Wen-Chih Chang; In-Gann Chen

2009-01-01

200

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

2013-03-21

201

Design of line\\/motor side capacitors for PWM CSR-CSI drives to achieve optimal power factor in high power fan\\/pump applications  

Microsoft Academic Search

The input power factor of GTO PWM current source rectifiers using a delay angle control scheme is investigated. It is discovered that with an optimal design of line and motor side capacitors for CSR-CSI induction motor drives having fan\\/pump loads, the input power factor is close to unity (over 0.95 for 30% to 100% of rated load). The concept of

Y. Xiao; B. Wu; N. R. Zargari; R. Sotudeh

1997-01-01

202

High-Performance n-type Organic Semiconductors: Incorporating Specific Electron-Withdrawing Motifs to Achieve Tight Molecular Stacking and Optimized Energy Levels  

SciTech Connect

Novel {pi}-conjugated cyanostilbene-based semiconductors (Hex-3,5-TFPTA and Hex-4-TFPTA) with tight molecular stacking and optimized energy levels are synthesized. Hex-4-TFPTA exhibits high-performance n-type organic field-effect transistor (OFET) properties with electron mobilities as high as 2.14 cm{sup 2} V{sup -1}s{sup -1} and on-off current ratios >10{sup 6}.

Park S. Y.; Yang L.; Yun, S.W.; Kim, J.H.; Shin, S.; Yang, H.; An B.

2012-01-16

203

Assessment of Optimal Virus-Mediated Growth Factor Gene Delivery for Human Cutaneous Wound Healing Enhancement  

Microsoft Academic Search

Using a recently described skin-humanized model based on the engraftment of human bioengineered skin equivalents onto immunodeficient mice, we compared the efficacy of different in vivo gene transfer strategies aimed at delivering growth factors to promote skin wound healing. The approaches involving transient delivery of keratinocyte growth factor (KGF) to wounds performed in the engrafted human skin included (1) KGF

María J Escámez; Marta Carretero; Marta García; Lucía Martínez-Santamaría; Isabel Mirones; Blanca Duarte; Almudena Holguín; Eva García; Verónica García; Alvaro Meana; José L Jorcano; Fernando Larcher; Marcela Del Río

2008-01-01

204

On the role of plant mitochondrial metabolism and its impact on photosynthesis in both optimal and sub-optimal growth conditions.  

PubMed

Given that the pathways of photosynthesis and respiration catalyze partially opposing processes, it follows that their relative activities must be carefully regulated within plant cells. Recent evidence has shown that the components of the mitochondrial electron transport chain are essential for the proper maintenance of intracellular redox gradients, to allow considerable rates of photorespiration and in turn efficient photosynthesis. Thus considerable advances have been made in understanding the interaction between respiration and photosynthesis during the last decades and the potential mechanisms linking mitochondrial function and photosynthetic efficiency will be reviewed. Despite the fact that manipulation of various steps of mitochondrial metabolism has been demonstrated to alter photosynthesis under optimal growth conditions, it is likely that these changes will, by and large, not be maintained under sub-optimal situations. Therefore producing plants to meet this aim remains a critical challenge. It is clear, however, that although there have been a range of studies analysing changes in respiratory and photosynthetic rates in response to light, temperature and CO2, our knowledge of the environmental impact on these processes and its linkage still remains fragmented. We will also discuss the metabolic changes associated to plant respiration and photosynthesis as important components of the survival strategy as they considerably extend the period that a plant can withstand to a stress situation. PMID:23456269

Araújo, Wagner L; Nunes-Nesi, Adriano; Fernie, Alisdair R

2013-02-28

205

Optimization of production of recombinant human growth hormone in Escherichia coli  

PubMed Central

Background: Human growth hormone (hGH) is a single-chain polypeptide that participates in a wide range of biological functions such as metabolism of proteins, carbohydrates and lipids as well as in growth, development and immunity. Growth hormone deficiency in human occurs both in children and adults. The routine treatment for this condition is administration of recombinant human growth hormone (rhGH) made by prokaryotes. Since nonglycosylated human growth hormone is a biologically active protein, prokaryotic expression systems are preferred for its production. Materials and Methods: Different strains of E.coli were transformed by plasmid containing human growth hormone gene and cultured in different conditions. After induction by IPTG, recombinant human growth hormone production was assessed using ELISA, dot blotting and western blotting techniques. Results: High levels of rhGH were produced using E.coli prokaryotic protein production system. Conclusion: This simple and cost effective production process could be recruited for large scale production of rhGH.

Rezaei, Marzieh; Zarkesh-Esfahani, Sayyed H.

2012-01-01

206

Optimation growth of platinum and palladium nanoparticles on stainless steel 316L and activated carbon pellet substrates  

NASA Astrophysics Data System (ADS)

In this study, an optimation growth of platinum (PtNs) and palladium (PdNs) nanoparticles has successfully grown on stainless steel 316L and activated carbon pellet as substrates. PtNs and PdNs were grown on the substrates by wet chemical method. The effect of concentration of ascorbic acid and multi-growth step had shown the significantly in density and particle size distribution on the both substrates. The morphology and the structure of PtNs and PdNs were characterized by a field-emission scanning electron microscope (FESEM), X-ray diffraction (XRD), respectively. Homogenous particles size and high density of PtNs and PdNs on the substrates were also successfully grown with current method.

Iwantono; Taer, E.; Umar, A. A.

2012-06-01

207

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

National Technical Information Service (NTIS)

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 cata...

A. M. Cassell S. Verma L. Delzeit M. Meyyappan J. Han

2000-01-01

208

Optimizing tubal epithelial cell growth promotes mouse embryo hatching in coculture  

Microsoft Academic Search

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

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

1996-01-01

209

Use of response surface methodology in a fed-batch process for optimization of tricarboxylic acid cycle intermediates to achieve high levels of canthaxanthin from Dietzia natronolimnaea HS-1.  

PubMed

In this work, we applied statistical experimental design to a fed-batch process for optimization of tricarboxylic acid cycle (TCA) intermediates in order to achieve high-level production of canthaxanthin from Dietzia natronolimnaea HS-1 cultured in beet molasses. A fractional factorial design (screening test) was first conducted on five TCA cycle intermediates. Out of the five TCA cycle intermediates investigated via screening tests, alfaketoglutarate, oxaloacetate and succinate were selected based on their statistically significant (P<0.05) and positive effects on canthaxanthin production. These significant factors were optimized by means of response surface methodology (RSM) in order to achieve high-level production of canthaxanthin. The experimental results of the RSM were fitted with a second-order polynomial equation by means of a multiple regression technique to identify the relationship between canthaxanthin production and the three TCA cycle intermediates. By means of this statistical design under a fed-batch process, the optimum conditions required to achieve the highest level of canthaxanthin (13172 + or - 25 microg l(-1)) were determined as follows: alfaketoglutarate, 9.69 mM; oxaloacetate, 8.68 mM; succinate, 8.51 mM. PMID:20226378

Nasri Nasrabadi, Mohammad Reza; Razavi, Seyed Hadi

2009-11-08

210

Optimal capacitor placement in a radial distribution system using Plant Growth Simulation Algorithm  

Microsoft Academic Search

This paper presents a new and efficient approach for capacitor placement in radial distribution systems that determine the optimal locations and size of capacitor with an objective of improving the voltage profile and reduction of power loss. The solution methodology has two parts: in part one the loss sensitivity factors are used to select the candidate locations for the capacitor

R. Srinivasas Rao; S. V. L. Narasimham; M. Ramalingaraju

2011-01-01

211

Long term growth responses of loblolly pine to optimal nutrient and ...  

Treesearch

Source: Forest Ecology and Management 192 (2004) 3-19. Description: A factorial combination of four treatments (control (CW), optimal growing season water availability (IW), optimum nutrient availability ... Irrigation effects were also positive for these parameters but the increases were much smaller than those found with ...

212

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

Microsoft Academic Search

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

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

213

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.

2013-01-01

214

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

215

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

2012-10-31

216

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

2008-11-25

217

Oxygen levels that optimize TSC culture are identified by maximizing growth rates and minimizing stress  

Microsoft Academic Search

Accumulating data suggest that 20% O2 causes human and mouse placental trophoblast stem cell (TSC) differentiation and suppresses proliferation. We tested the hypotheses that phosphorylated stress-activated protein kinase (pSAPK) levels report the optimal O2 level for TSC culture, and that pSAPK responds to contradictory signals. We tested the dose range of 0–20% O2 (0, 0.5, 2, and 20%) on five

S. Zhou; Y. Xie; E. E. Puscheck; D. A. Rappolee

2011-01-01

218

Long term growth responses of loblolly pine to optimal nutrient and water resource availability  

Microsoft Academic Search

A factorial combination of four treatments (control (CW), optimal growing season water availability (IW), optimum nutrient availability (FW), and combined optimum water and nutrient availability (FIW)) in four replications were initiated in an 8-year-old Pinus taeda stand growing on a droughty, nutrient-poor, sandy site in Scotland County, NC and maintained for 9 years. Results for the first 4 years after

Timothy J. Albaugh; H. Lee Allen; Phillip M. Dougherty; Kurt H. Johnsen

2004-01-01

219

Optimal Induced Innovation and Growth with Congestion of a Limited Natural Resource  

Microsoft Academic Search

In a simple Neoclassical Growth Model with endogenous technical change, I expand on the hypothesis of Induced Innovation including a production externality from a xed input, called `land', which represents the carrying capacity of the earth's atmosphere. Land is assumed to be congested by the use of labor and capital in production. A market economy where land is free will

Daniele Tavani

2008-01-01

220

Predicting spacing effects on growth and optimal rotations of tropical multipurpose trees  

Microsoft Academic Search

In order to improve our ability to analyze growth of tropical fast-growing trees, we developed a simple model (MPTGro) to predict development of even-aged stands from allometric equations of leaf area and total biomass. and a competition index based on wood production per unit leaf area, or net assimilation rate (E). In this study we (1) tested te model assumption

Robin A. Harrington; James H. Fownes

1996-01-01

221

Maximin-optimal sustainable growth in a resource-based imperfect economy  

Microsoft Academic Search

I offer an approach linking a welfare criterion to the opportunities for sustainable development in an imperfect economy. The approach implies a dependence of the criterion on the economy's current state. The economy-linked criterion is constructed using an example with the maximin principle applied to a hybrid level-growth measure. This measure includes as special cases the conventional measures of consumption

Andrei V. Bazhanova

2008-01-01

222

Optimization of Inclusion Body Solubilization and Renaturation of Recombinant Human Growth Hormone from Escherichia coli  

Microsoft Academic Search

Recombinant human growth hormone (r-hGH) was expressed in Escherichia coli as inclusion bodies. In 10 h of fed-batch fermentation, 1.6 g\\/L of r-hGH was produced at a cell concentration of 25 g dry cell weight\\/L. Inclusion bodies from the cells were isolated and purified to homogeneity. Various buffers with and without reducing agents were used to solubilize r-hGH from the

Ashok K Patra; R Mukhopadhyay; R Mukhija; Anuja Krishnan; L. C Garg; Amulya K Panda

2000-01-01

223

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

SciTech Connect

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

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

2010-01-01

224

Theory-guided growth of aluminum antimonide single crystals with optimal properties for radiation detection  

NASA Astrophysics Data System (ADS)

First-principles calculations are used to study the thermodynamic and electronic properties of a large set of intrinsic and extrinsic defects in AlSb. The results are employed in conjunction with experimental impurity data to devise an improved growth process for mitigating the detrimental effects of native defects and impurities. A codoping strategy using Te is demonstrated that leads to a significant increase in both mobility and resistivity without introducing lifetime-limiting deep levels. The resulting material exhibits an order of magnitude improvement in mobility-lifetime product and allows spectroscopic detection of ? particles with AlSb.

Erhart, Paul; A?Berg, Daniel; Sturm, Benjamin W.; Wu, Kuang-Jen; Lordi, Vincenzo

2010-10-01

225

Macro-level optimized deployment of an electrolyser-based hydrogen refuelling infrastructure with demand growth  

NASA Astrophysics Data System (ADS)

Hydrogen-powered vehicles are receiving a significant amount of attention due to their potential for reduced greenhouse gas emissions, increased production pathways, and the higher efficiencies of fuel cells as compared to internal combustion engines. A major obstacle to the commercialization of hydrogen vehicles is the lack of a developed hydrogen refuelling infrastructure. A cost-effective infrastructure requires a significant number of hydrogen-powered vehicles in use. A plausible solution to the 'chicken and egg' dilemma requires the development of an infrastructure prior to competitive economic viability. This article employs optimization techniques to design a public-policy-supported infrastructure at minimum cost as the number of hydrogen vehicles increases from 10 to 100,000. The specific case used is the development of an infrastructure across a major Canadian highway spanning South Ontario and Western Quebec.

Stevens, M. B.; Fowler, M. W.; Elkamel, A.; Elhedhli, S.

2008-10-01

226

Increasing Costs Due to Ocean Acidification Drives Phytoplankton to Be More Heavily Calcified: Optimal Growth Strategy of Coccolithophores  

PubMed Central

Ocean acidification is potentially one of the greatest threats to marine ecosystems and global carbon cycling. Amongst calcifying organisms, coccolithophores have received special attention because their calcite precipitation plays a significant role in alkalinity flux to the deep ocean (i.e., inorganic carbon pump). Currently, empirical effort is devoted to evaluating the plastic responses to acidification, but evolutionary considerations are missing from this approach. We thus constructed an optimality model to evaluate the evolutionary response of coccolithophorid life history, assuming that their exoskeleton (coccolith) serves to reduce the instantaneous mortality rates. Our model predicted that natural selection favors constructing more heavily calcified exoskeleton in response to increased acidification-driven costs. This counter-intuitive response occurs because the fitness benefit of choosing a better-defended, slower growth strategy in more acidic conditions, outweighs that of accelerating the cell cycle, as this occurs by producing less calcified exoskeleton. Contrary to the widely held belief, the evolutionarily optimized population can precipitate larger amounts of CaCO3 during the bloom in more acidified seawater, depending on parameter values. These findings suggest that ocean acidification may enhance the calcification rates of marine organisms as an adaptive response, possibly accompanied by higher carbon fixation ability. Our theory also provides a compelling explanation for the multispecific fossil time-series record from ?200 years ago to present, in which mean coccolith size has increased along with rising atmospheric CO2 concentration.

Irie, Takahiro; Bessho, Kazuhiro; Findlay, Helen S.; Calosi, Piero

2010-01-01

227

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).…

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

2010-01-01

228

Tumor Growth Rate Determines the Timing of Optimal Chronomodulated Treatment Schedules  

PubMed Central

In host and cancer tissues, drug metabolism and susceptibility to drugs vary in a circadian (24 h) manner. In particular, the efficacy of a cell cycle specific (CCS) cytotoxic agent is affected by the daily modulation of cell cycle activity in the target tissues. Anti-cancer chronotherapy, in which treatments are administered at a particular time each day, aims at exploiting these biological rhythms to reduce toxicity and improve efficacy of the treatment. The circadian status, which is the timing of physiological and behavioral activity relative to daily environmental cues, largely determines the best timing of treatments. However, the influence of variations in tumor kinetics has not been considered in determining appropriate treatment schedules. We used a simple model for cell populations under chronomodulated treatment to identify which biological parameters are important for the successful design of a chronotherapy strategy. We show that the duration of the phase of the cell cycle targeted by the treatment and the cell proliferation rate are crucial in determining the best times to administer CCS drugs. Thus, optimal treatment times depend not only on the circadian status of the patient but also on the cell cycle kinetics of the tumor. Then, we developed a theoretical analysis of treatment outcome (TATO) to relate the circadian status and cell cycle kinetic parameters to the treatment outcomes. We show that the best and the worst CCS drug administration schedules are those with 24 h intervals, implying that 24 h chronomodulated treatments can be ineffective or even harmful if administered at wrong circadian times. We show that for certain tumors, administration times at intervals different from 24 h may reduce these risks without compromising overall efficacy.

Bernard, Samuel; Cajavec Bernard, Branka; Levi, Francis; Herzel, Hanspeter

2010-01-01

229

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

230

Application of GA in optimization of pore network models generated by multi-cellular growth algorithms  

NASA Astrophysics Data System (ADS)

In pore network modeling, the void space of a rock sample is represented at the microscopic scale by a network of pores connected by throats. Construction of a reasonable representation of the geometry and topology of the pore space will lead to a reliable prediction of the properties of porous media. Recently, the theory of multi-cellular growth (or L-systems) has been used as a flexible tool for generation of pore network models which do not require any special information such as 2D SEM or 3D pore space images. In general, the networks generated by this method are irregular pore network models which are inherently closer to the complicated nature of the porous media rather than regular lattice networks. In this approach, the construction process is controlled only by the production rules that govern the development process of the network. In this study, genetic algorithm has been used to obtain the optimum values of the uncertain parameters of these production rules to build an appropriate irregular lattice network capable of the prediction of both static and hydraulic information of the target porous medium.

Jamshidi, Saeid; Boozarjomehry, Ramin Bozorgmehry; Pishvaie, Mahmoud Reza

2009-10-01

231

Polluting NonRenewable Resources and Growth  

Microsoft Academic Search

In an endogenous growth model with human capital accumulation, we introduce non-renewable resources which cause flow pollution problems. In this set-up the negative external effect of pollution on productivity does not cause any distortions in the economy: The market economy will achieve the optimal extraction and growth rates. Consequently, emission taxes are unnecessary and, when introduced, will have no effect

Poul Schou

2000-01-01

232

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

233

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

PubMed

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

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

2013-01-01

234

Optimized processing of growth factor mobilized peripheral blood CD34+ products by counterflow centrifugal elutriation.  

PubMed

Cell separation by counterflow centrifugal elutriation has been described for the preparation of monocytes for vaccine applications, but its use in other current good manufacturing practice (cGMP) operations has been limited. In this study, growth factor-mobilized peripheral blood progenitor cell products were collected from healthy donors and processed by elutriation using a commercial cell washing device. Fractions were collected for each product as per the manufacturer's instructions or using a modified protocol developed in our laboratory. Each fraction was analyzed for cell count, viability, and blood cell differential. Our data demonstrate that, using standard elutriation procedures, >99% of red blood cells and platelets were removed from apheresis products with high recoveries of total white blood cells and enrichment of CD34+ cells in two of five fractions. With modification of the basic protocol, we were able to collect all of the CD34+ cells in a single fraction. The CD34-enriched fractions were formulated, labeled with a ferromagnetic antibody to CD34, washed using the Elutra device, and transferred directly to a magnetic bead selection device for further purification. CD34+ cell purities from the column were extremely high (98.7 ± 0.9%), and yields were typical for the device (55.7 ± 12.3%). The processes were highly automated and closed from receipt of the apheresis product through formulation of target-enriched cell fractions. Thus, elutriation is a feasible method for the initial manipulations associated with primary blood cell therapy products and supports cGMP and current good tissue practice-compliant cell processing. PMID:23197821

Tran, Chy-Anh; Torres-Coronado, Monica; Gardner, Agnes; Gu, Angel; Vu, Hieu; Rao, Anitha; Cao, Lan-Feng; Ahmed, Amira; Digiusto, David

2012-05-08

235

Optimization of a coupled hydrology–crop growth model through the assimilation of observed soil moisture and leaf area index values using an ensemble Kalman filter  

Microsoft Academic Search

It is well known that the presence and development stage of vegetation largely influences the soil moisture content. In its turn, soil moisture availability is of major importance for the development of vegetation. The objective of this paper is to assess to what extent the results of a fully coupled hydrology–crop growth model can be optimized through the assimilation of

Valentijn R. N. Pauwels; Niko E. C. Verhoest; Gabriëlle J. M. De Lannoy; Vincent Guissard; Cozmin Lucau; Pierre Defourny

2007-01-01

236

Optimizing Fungicide Timing for the Control of Rhizoctonia Crown and Root Rot of Sugar Beet Using Soil Temperature and Plant Growth Stages  

Microsoft Academic Search

Kirk, W. W., Wharton, P. S., Schafer, R. L., Tumbalam, P., Poindexter, S., Guza, C., Fogg, R., Schlatter, T., Stewart, J., Hubbell, L., and Ruppal, D. 2008. Optimizing fungicide timing for the control of Rhizoctonia crown and root rot of sugar beet using soil temperature and plant growth stages. Plant Dis. 92:1091-1098. Azoxystrobin is applied early in the sugar beet

W. W. Kirk; P. S. Wharton; R. L. Schafer; P. Tumbalam; S. Poindexter; C. Guza; R. Fogg; T. Schlatter; J. Stewart; L. Hubbell; D. Ruppal

2008-01-01

237

Interfacial conditions between a press-fit acetabular cup and bone during daily activities: implications for achieving bone in-growth  

Microsoft Academic Search

Interfacial gaps and relative micromotions during activities are widely believed to restrict the boney in-growth process of non-cemented acetabular cups. Using finite element modeling of the cup–bone system, relative micromotions and interfacial gaps are calculated for walking slow, normal and fast and for climbing upstairs, downstairs and standing up from a chair. A 2mm press-fit is simulated and interfacial conditions

Iain R Spears; Martin Pfleiderer; Erich Schneider; Ekkehard Hille; Georg Bergmann; Michael M Morlock

2000-01-01

238

Radiolabeled cetuximab: dose optimization for epidermal growth factor receptor imaging in a head-and-neck squamous cell carcinoma model.  

PubMed

Noninvasive imaging of the epidermal growth factor receptor (EGFR) in head-and-neck squamous cell carcinoma could be of value to select patients for EGFR-targeted therapy. We assessed dose optimization of (111) Indium-DTPA-cetuximab ((111) In-cetuximab) for EGFR imaging in a head-and-neck squamous cell carcinoma xenograft model. (111) In-cetuximab slowly internalized into FaDu cells in vitro, amounting to 1.0 × 10(4) molecules cetuximab per cell after 24 hr (15.8% of added activity). In nude mice with subcutaneous FaDu xenograft tumors, a protein dose escalation study with (111) In-cetuximab showed highest specific accumulation in tumors at protein doses between 1 and 30 ?g per mouse (mean tumor uptake 33.1 ± 3.1%ID/g, 3 days postinjection (p.i.)). The biodistribution of (111) In-cetuximab and (125) I-cetuximab was determined at 1, 3 and 7 days p.i. at optimal protein dose. Tumor uptake was favorable for (111) In-cetuximab compared to (125) I-cetuximab. With pixel-by-pixel analysis, good correlations were found between intratumoral distribution of (111) In-cetuximab as determined by autoradiography and EGFR expression in the same tumor sections as determined immunohistochemically (mean r = 0.74 ± 0.14; all correlations p < 0.0001). Micro Single Photon Emission Computed Tomography (MicroSPECT) scans clearly visualized FaDu tumors from 1 day p.i. onward and tumor-to-background contrast increased until 7 days p.i. (tumor-to-liver ratios 0.58 ± 0.24, 3.42 ± 0.66, 8.99 ± 4.66 and 16.33 ± 11.56, at day 0, day 1, day 3 and day 7 p.i., respectively). Our study suggests that, at optimal cetuximab imaging dose, (111) In-cetuximab can be used for visualization of EGFR expression in head-and-neck squamous cell carcinoma using SPECT. PMID:20957635

Hoeben, Bianca A W; Molkenboer-Kuenen, Janneke D M; Oyen, Wim J G; Peeters, Wenny J M; Kaanders, Johannes H A M; Bussink, Johan; Boerman, Otto C

2010-12-01

239

Preparation and optimization of epitaxial growth of transparent ZnO nanotip thin films by hydrothermal method.  

PubMed

Zinc oxide (ZnO) nanotip thin films were prepared on ZnO coated nanocrystalline ITO/glass substrates by hydrothermal method. In order to obtain the ZnO nanotip arrays with high aspect ratio, the experimental conditions were optimized. The scanning electron microscope images showed that the surface morphology of ZnO thin films could be easily manipulated by changing the seed layer thickness and growth time. The ZnO nanotip thin films were grown epitaxially on ZnO seed layer coated ITO/glass substrates. The surface morphology of ZnO thin films on ITO/glass substrate changed from nanorods with a flat-top end to nanotips as the growth time was increased from 3 to 15 h. The ZnO thin films prepared under these deposition conditions were highly oriented along (002) direction. The as-prepared sample (15 h) was annealed at different temperatures (30, 100, 150, and 270 degrees C). The surface morphologies of annealed ZnO thin films did not show any remarkable change and the best crystallinity was observed at 100 degrees C. The photoluminescence spectra showed that the near band edge emission shifted to shorter wavelength as the annealing temperature was increased from 30 to 270 degrees C, it was due to the intrinsic stress in the films. This was confirmed by X-ray diffraction analyses. NPB thin films were prepared on ITO/clay and ITO/glass substrates by thermal evaporation method. The electrical properties of Ag/NPB/ITO/Clay showed the Ohmic characteristics (J proportional V(1.0)). The J-V characteristic of Ag/NPB/PMMA/ZnO/ITO/Glass showed good rectification behaviour with a diode-ideality factor of 1.36. PMID:22852303

Venkatachalm, S; Hayashi, H; Ebina, T; Kawasaki, K; Nakamura, T; Nanjo, H

2012-05-01

240

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

PubMed

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

Ercan, Duygu; Demirci, Ali

2013-05-09

241

Growth  

Microsoft Academic Search

\\u000a This chapter is devoted to the growth of ZnO. It starts with various techniques to grow bulk samples and presents in some\\u000a detail the growth of epitaxial layers by metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and\\u000a pulsed laser deposition (PLD). The last section is devoted to the growth of nanorods. Some properties of the resulting samples

Andreas Waag

2010-01-01

242

Optimal and adaptive testing for software reliability assessment  

Microsoft Academic Search

Abstract Optimal software testing is concerned with how to test software such that the underlying testing goal is achieved in an optimal manner. Our previous work shows,that the optimal testing problem,for software reliability growth can be treated as closed-loop or feedback,control problem, where the software under test serves as a controlled object and the software testing strategy serves as the

Kai-yuan Cai; Yong-chao Li; Ke Liu

2004-01-01

243

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

244

Statistical optimization of the growth factors for Chaetoceros neogracile using fractional factorial design and central composite design.  

PubMed

Statistical experimental designs; involving (i) a fractional factorial design (FFD) and (ii) a central composite design (CCD) were applied to optimize the culture medium constituents for production of a unique antifreeze protein by the Antartic microalgae Chaetoceros neogracile. The results of the FFD suggested that NaCl, KCl, MgCl2, and Na2SiO3 were significant variables that highly influenced the growth rate and biomass production. The optimum culture medium for the production of an antifreeze protein from C. neogracile was found to be Kalleampersandrsquor;s artificial seawater, pH of 7.0ampersandplusmn;0.5, consisting of 28.566 g/l of NaCl, 3.887 g/l of MgCl2, 1.787 g/l of MgSO4, 1.308 g/l of CaSO4, 0.832 g/l of K2SO4, 0.124 g/l of CaCO3, 0.103 g/l of KBr, 0.0288 g/l of SrSO4, and 0.0282 g/l of H3BO3. The antifreeze activity significantly increased after cells were treated with cold shock (at -5oC) for 14 h. To the best of our knowledge, this is the first report demonstrating an antifreeze-like protein of C. neogracile. PMID:19131694

Jeong, Sung-Eun; Park, Jae-Kweon; Kim, Jeong-Dong; Chang, In-Jeong; Hong, Seong-Joo; Kang, Sung-Ho; Lee, Choul-Gyun

2008-12-01

245

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

PubMed

The goal of this study was to examine factors that contribute to energy balance in female GHR -/- mice. We measured energy intake, energy expenditure (EE), fuel utilization, body mass (M(b)) changes and physical activity in 17month-old female GHR -/- mice and their age-matched wild type littermates. The GHR -/- mice were smaller, consumed more food per unit M(b), had greater EE per unit M(b) and had an increase in 24-h EE/M(b) that was similar to the increase in their surface-area-to-volume ratio. Locomotor activity (LMA) was reduced in the GHR -/- mice, but the energetic cost associated with their LMA was greater than in wild type controls. Furthermore, M(b) and LMA were independent explanatory covariates of most of the variance in EE, and when adjusted for M(b) and LMA, the GHR -/- mice had higher EE during both the light and dark phases of the daily cycle. Respiratory quotient was lower in GHR -/- mice during the light phase, which indicated a greater utilization of lipid relative to carbohydrate in these mice. Additionally, GHR -/- mice had higher ratios of caloric intake to EE at several intervals during the dark phase, and this effect was greater and more sustained in the final 3h of the dark phase. Therefore, we conclude that GHR -/- mice are able to overcome the substantial energetic challenges of dwarfism through several mechanisms that promote stable M(b). Relative to wild type mice, the GHR -/- mice consumed more calories per unit M(b), which offset the disproportionate increase in their daily energy expenditure. While GHR -/- mice oxidized a greater proportion of lipid during the light phase in order to meet their energy requirements, they achieved greater energy efficiency and storage during the dark phase through a combination of higher energy consumption and lower LMA. PMID:19747867

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

2009-09-10

246

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

PubMed Central

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

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

2009-01-01

247

CdSe\\/ZnSe Quantum Dots Formed by Low Temperature Epitaxy and In-Situ Annealing: Properties and Growth Optimization  

Microsoft Academic Search

The formation of CdSe\\/ZnSe quantum dots by a method combining a low temperature MBE growth of a CdSe layer and its subsequent in-situ annealing at temperatures between 280-340ºC has been studied. The thermal treatment results in a re-organization of the surface from a nearly two-dimensional layer to an ensemble of three-dimensional dot-like features. In this work we optimized the different

S. Mahapatra; C. Schumacher; T. Kiessling; G. V. Astakhov; U. Bass; W. Ossau; J. Geurts; K. Brunner

2006-01-01

248

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

Microsoft Academic Search

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

Tsutomu Muranaka; Chao Jiang; Akira Ito; Hideki Hasegawa

2001-01-01

249

Simultaneous versus sequential optimal experiment design for the identification of multi-parameter microbial growth kinetics as a function of temperature.  

PubMed

Optimal experiment design for parameter estimation (OED/PE) has become a popular tool for efficient and accurate estimation of kinetic model parameters. When the kinetic model under study encloses multiple parameters, different optimization strategies can be constructed. The most straightforward approach is to estimate all parameters simultaneously from one optimal experiment (single OED/PE strategy). However, due to the complexity of the optimization problem or the stringent limitations on the system's dynamics, the experimental information can be limited and parameter estimation convergence problems can arise. As an alternative, we propose to reduce the optimization problem to a series of two-parameter estimation problems, i.e., an optimal experiment is designed for a combination of two parameters while presuming the other parameters known. Two different approaches can be followed: (i) all two-parameter optimal experiments are designed based on identical initial parameter estimates and parameters are estimated simultaneously from all resulting experimental data (global OED/PE strategy), and (ii) optimal experiments are calculated and implemented sequentially whereby the parameter values are updated intermediately (sequential OED/PE strategy). This work exploits OED/PE for the identification of the Cardinal Temperature Model with Inflection (CTMI) (Rosso et al., 1993). This kinetic model describes the effect of temperature on the microbial growth rate and encloses four parameters. The three OED/PE strategies are considered and the impact of the OED/PE design strategy on the accuracy of the CTMI parameter estimation is evaluated. Based on a simulation study, it is observed that the parameter values derived from the sequential approach deviate more from the true parameters than the single and global strategy estimates. The single and global OED/PE strategies are further compared based on experimental data obtained from design implementation in a bioreactor. Comparable estimates are obtained, but global OED/PE estimates are, in general, more accurate and reliable. PMID:20064532

Van Derlinden, E; Bernaerts, K; Van Impe, J F

2010-01-11

250

Growth optimization and characterization of lattice-matched Al0.82In0.18N optical confinement layer for edge emitting nitride laser diodes  

NASA Astrophysics Data System (ADS)

We present the growth optimization and the doping by the metal organic chemical vapor deposition of lattice-matched Al0.82In0.18N bottom optical confinement layers for edge emitting laser diodes. Due to the increasing size and density of V-shaped defects in Al1-xInxN with increasing thickness, we have designed an Al1-xInxN/GaN multilayer structure by optimizing the growth and thickness of the GaN interlayer. The Al1-xInxN and GaN interlayers in the multilayer structure were both doped using the same SiH4 flow, while the Si levels in both layers were found to be significantly different by SIMS. The optimized 8×(Al0.82In0.18N/GaN=54/6 nm) multilayer structures grown on free-standing GaN substrates were characterized by high resolution X-ray diffraction, atomic force microscopy and transmission electron microscopy, along with the in-situ measurements of stress evolution during growth. Finally, lasing was obtained from the UV (394 nm) to blue (436 nm) wavelengths, in electrically injected, edge-emitting, cleaved-facet laser diodes with 480 nm thick Si-doped Al1-xInxN/GaN multilayers as bottom waveguide claddings.

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

2012-01-01

251

Generating growth alternatives  

US Patent & Trademark Office Database

The present invention is an apparatus and method for determining when a living animal reaches its optimum rate of growth. This information is then used to calculate the optimal parameters for achieving the maximum Return On Investment. The computer determines the optimal number of birds for a flock, type and amount of feed, length of time between hatching and sale to food processor, etc. The computer consists of a microprocessor, random access memory, a storage device, a keyboard, a computer screen, a printer, a math co-processor.

2000-09-05

252

Achieving high Curie temperature in (Ga,Mn)As  

SciTech Connect

We study the effects of growth temperature, Ga:As ratio, and postgrowth annealing procedure on the Curie temperature T{sub C} of (Ga,Mn)As layers grown by molecular beam epitaxy. We achieve the highest T{sub C} values for growth temperatures very close to the two-dimensional-three-dimensional phase boundary. The increase in T{sub C}, due to the removal of interstitial Mn by postgrowth annealing, is counteracted by a second process, which reduces T{sub C} and which is more effective at higher annealing temperatures. Our results show that it is necessary to optimize the growth parameters and postgrowth annealing procedure to obtain the highest T{sub C}.

Wang, M.; Campion, R. P.; Rushforth, A. W.; Edmonds, K. W.; Foxon, C. T.; Gallagher, B. L. [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

2008-09-29

253

Accelerated Head and Body Growth in Infants Later Diagnosed With Autism Spectrum Disorders: A Comparative Study of Optimal Outcome Children  

Microsoft Academic Search

Previous research has demonstrated accelerated head and body growth during infancy in children with autism spectrum disorders. No study has yet examined head growth in children who lose their autism spectrum disorder diagnoses. Head circumference, length, and weight growth during infancy for 24 children who maintained their diagnoses were compared with 15 children who lost their diagnoses, and to 37

Krista D. Mraz; James Dixon; Thyde Dumont-Mathieu; Deborah Fein

2009-01-01

254

Enhanced heteroepitaxial growth of CoCrPt-SiO{sub 2} perpendicular magnetic recording media on optimized Ru intermediate layers  

SciTech Connect

The crystallographic growth, interfacial roughness, and magnetic properties of CoCrPt-SiO{sub 2} perpendicular magnetic recording media prepared on various types of Ru intermediate growth layers were systematically investigated based on high angle and omega offset x-ray diffraction scans, rocking curve scans, synchrotron radiation based grazing incidence reflectivity scans, and magneto-optical Kerr hysteresis loops. For samples that make use of one Ru growth layer, voltage bias applied on the Ru layer was seen to have two observable effects: (1) the dispersion in the Ru(00{center_dot}2) perpendicular texture increased, but that of the Co(00{center_dot}2) remained unchanged, leading to identical layered growth and (2) the in-plane a-lattice parameter of the Ru decreased leading to enhanced heteroepitaxy with the Co. There was no significant change in the Ru-Co interfacial roughness with changing the bias on the Ru layer. The bias effect can be used to optimize the design of the Ru intermediate layers. A scheme that makes use of two Ru growth layers consisting of a bottom Ru layer prepared under zero bias, which is inserted below a second Ru layer prepared under biased conditions, is shown to lead to significant benefits such as improved texture without affecting the magnetic properties. This is due to the different functional roles ascribed to each of the Ru growth layers.

Srinivasan, Kumar; Piramanayagam, S. N. [Data Storage Institute, A-STAR, 5 Engineering Drive 1, Singapore 117608 (Singapore)

2008-01-15

255

Growth of wildtype and mutant E. coli strains in minimal media for optimal production of nucleic acids for preparing labeled nucleotides  

PubMed Central

Since RNAs lie at the center of most cellular processes, there is a need for synthesizing large amounts of RNAs made from stable isotope-labeled nucleotides to advance the study of their structure and dynamics by nuclear magnetic resonance (NMR) spectroscopy. A particularly effective means of obtaining labeled nucleotides is to harvest these nucleotides from bacteria grown in defined minimal media supplemented with 15NH4Cl and various carbon sources. Given the high cost of carbon precursors required for labeling nucleic acids for NMR studies, it becomes important to evaluate the optimal growth for commonly used strains under standard minimal media conditions. Such information is lacking. In this study, we characterize the growth for Escherichia coli strains K12, K10zwf, and DL323 in three minimal media with isotopic-labeled carbon sources of acetate, glycerol, and glycerol combined with formate. Of the three media, the LeMaster-Richards and the Studier media outperform the commonly used M9 media and both support optimal growth of E. coli for the production of nucleotides. However, the growth of all three E. coli strains in acetate is reduced almost twofold compared to growth in glycerol. Analysis of the metabolic pathway and previous gene array studies help to explain this differential growth in glycerol and acetate. These studies should benefit efforts to make selective 13C-15N isotopic-labeled nucleotides for synthesizing biologically important RNAs. Electronic supplementary material The online version of this article (doi:10.1007/s00253-010-2813-y) contains supplementary material, which is available to authorized users.

Thakur, Chandar S.; Brown, Margaret E.; Sama, Jacob N.; Jackson, Melantha E.

2010-01-01

256

The Future of Optimism  

Microsoft Academic Search

Recent theoretical discussions of optimism as an inherent aspect of human nature converge with empirical investigations of optimism as an individual difference to show that optimism can be a highly beneficial psychological characteristic linked to good mood, perseverance, achievement, and physical health. Questions remain about optimism as a research topic and more generally as a societal value. Is the meaning

Christopher Peterson

2000-01-01

257

Seasonal Variation in Frequency of Isolation of Ophiosphaerella korrae from Bermudagrass Roots in Mississippi and Pathogenicity and Optimal Growth of Selected Isolates.  

PubMed

Isolation frequency of Ophiosphaerella korrae (spring dead spot pathogen) from Cynodon dactylon (bermudagrass) roots at a golf course near West Point, Mississippi, was monitored over a 3-year investigation. Laboratory and greenhouse experiments were conducted to determine optimal temperatures for the growth of selected O. korrae isolates collected from the field study and to evaluate those isolates for pathogenicity potential. Isolation frequencies of the pathogen from naturally infested root samples were significantly higher in the winter and spring and lowest in the fall regardless of cultural, nutrient, and chemical treatments. Annual soil temperatures ranged between 8 and 29 degrees C, and no correlation was observed between temperature and percent isolation of O. korrae. Optimal in vitro growth of selected O. korrae isolates ranged from 21 to 25 degrees C. Root discoloration was significantly greater in the presence of O. korrae compared to non-inoculated roots in greenhouse studies. Results of this study confirm and are the first to document that O. korrae naturally infests roots throughout the bermudagrass growth cycle, but factors other than temperature and management practices may influence O. korrae in situ. PMID:20119850

Perry, D Hunter; Tomaso-Peterson, Maria; Baird, Richard

2010-02-02

258

Suppressing void defects in long wavelength semipolar (2021) InGaN quantum wells by growth rate optimization  

NASA Astrophysics Data System (ADS)

We report on void defect formation in (2021) semipolar InGaN quantum wells (QWs) emitting in the green spectral region. Fluorescence and transmission electron microscopy studies indicate that this type of defect is associated with voids with {1011}, {1010}, and {0001} side facets in the QW region. Systematic growth studies show that this defect can be effectively suppressed by reducing the growth rate for the active region. Green light-emitting diodes (LEDs) with reduced active region growth rate showed enhanced power and wavelength performance. The improved LED performance is attributed to the absence of void defects in the active region.

Zhao, Yuji; Wu, Feng; Huang, Chia-Yen; Kawaguchi, Yoshinobu; Tanaka, Shinichi; Fujito, Kenji; Speck, James S.; DenBaars, Steven P.; Nakamura, Shuji

2013-03-01

259

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

260

Improved isolated microspore culture efficiency in medium with maltose and optimized growth regulator combination in japonica rice (Oryza sativa)  

Microsoft Academic Search

The influence of maltose and growth regulators on microspore culture response was investigated in japonica rice. High frequency of callus induction of isolated microspores was obtained with liquid medium containing MS salts, 100 mg l-1 myo-inositol, 1 mg l-1 thiamine-HCl, 500 mg l-1 glutamine, 60 g l-1 maltose, and several growth regulators. The effect of maltose on promoting callus formation

Jiahua Xie; Mingwei Gao; Qihua Cai; Xiongying Cheng; Yuwei Shen; Zhuqing Liang

1995-01-01

261

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.

2012-01-01

262

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

263

Achieving the Benefits of Safeguards by Design.  

National Technical Information Service (NTIS)

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 n...

B. Meppen J. Hocker J. Morgan R. Bean T. Biornard

2008-01-01

264

Increased plasma vascular endothelial growth factor (VEGF) as a surrogate marker for optimal therapeutic dosing of VEGF receptor-2 monoclonal antibodies.  

PubMed

A major obstacle compromising the successful application of many of the new targeted anticancer drugs, including angiogenesis inhibitors, is the empiricism associated with determining an effective biological/therapeutic dose because many of these drugs express optimum therapeutic activity below the maximum tolerated dose, if such a dose can be defined. Hence, surrogate markers are needed to help determine optimal dosing. Here we describe such a molecular marker, increased plasma levels of vascular endothelial growth factor (VEGF), in normal or tumor-bearing mice that received injections of an anti-VEGF receptor (VEGFR)-2 monoclonal antibody, such as DC101. Rapid increases of mouse VEGF (e.g., within 24 hours) up to 1 order of magnitude were observed after single injections of DC101 in non-tumor-bearing severe combined immunodeficient or nude mice; similar increases in human plasma VEGF were detected in human tumor-bearing mice. RAFL-1, another anti-VEGFR-2 antibody, also caused a significant increase in plasma VEGF. In contrast, increases in mouse VEGF levels were not seen when small molecule VEGFR-2 inhibitors were tested in normal mice. Most importantly, the increases in plasma VEGF were induced in a dose-dependent manner, with the maximum values peaking when doses previously determined to be optimally therapeutic were used. Plasma VEGF should be considered as a possible surrogate pharmacodynamic marker for determining the optimal biological dose of antibody drugs that block VEGFR-2 (KDR) activity in a clinical setting. PMID:15374976

Bocci, Guido; Man, Shan; Green, Shane K; Francia, Giulio; Ebos, John M L; du Manoir, Jeanne M; Weinerman, Adina; Emmenegger, Urban; Ma, Li; Thorpe, Philip; Davidoff, Andrew; Huber, James; Hicklin, Daniel J; Kerbel, Robert S

2004-09-15

265

Optimization of abiotic factors for improved growth and extracellular production of recombinant fungal phytase in sesame hairy root cultures  

Microsoft Academic Search

The effects of various abiotic factors, including polyethylene glycol (PEG), silver nitrate (AgNO3) and potassium phosphate (KH2PO4) on biomass growth, extracellular production of recombinant fungal phytase and its transcription activity by realtime RT-PCR\\u000a were examined with transformed sesame hairy roots. The PEG treatments decreased both biomass growth (80.5?82.3%) and phytase\\u000a production (82.1?96.4%) at all concentrations tested, except 1.0 g\\/L PEG,

Jae-An Chun; Woo-Hyup Lee; Mi-Ok Han; Jin-Woo Lee; Young-Byung Yi; Gun-Yong Park; Chung-Han Chung

2007-01-01

266

Lowering Bone Mineral Affinity of Bisphosphonates as a Therapeutic Strategy to Optimize Skeletal Tumor Growth Inhibition In vivo  

Microsoft Academic Search

Bisphosphonates bind avidly to bone mineral and are potent inhibitors of osteoclast-mediated bone destruction. They also exhibit antitumor activity in vitro. Here, we used a mouse model of human breast cancer bone metastasis to examine the effects of risedronate and NE-10790, a phosphonocarboxylate analogue of the bisphosphonate risedronate, on osteolysis and tumor growth. Osteolysis was measured by radiography and histomorphometry.

Pierrick G. J. Fournier; Florence Daubine; Mark W. Lundy; Michael J. Rogers; Frank H. Ebetino; Philippe Clezardin

2008-01-01

267

Enhanced Growth of Influenza Vaccine Seed Viruses in Vero Cells Mediated by Broadening the Optimal pH Range for Virus Membrane Fusion  

PubMed Central

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.

Murakami, Shin; Ito, Mutsumi; Takano, Ryo; Katsura, Hiroaki; Shimojima, Masayuki

2012-01-01

268

The study of optimizing growth conditions for improving field emission property of W18O49 nanorod arrays  

NASA Astrophysics Data System (ADS)

Large-area tungsten oxide nanorod arrays were synthesized by the catalyst-free tungsten hot-filament thermal vapor method. The diameter, height, interval and alignment of the nanorods were all found to be sensitive to the distance between hot filament and substrates. And the field emission property of the nanorod arrays prepared at various distances was shown to be significantly different. This demonstrates that optimal conditions can be found for preparing W18O49 nanorod arrays of better field emission property.

Chi, L. F.; Deng, S. Z.; Xu, N. S.; Chen, J.; She, J. C.; Liang, X. H.

2009-09-01

269

Optimization of the Growth Culture Medium with Traditional Chinese Herbs and Conditions of Bacillus Licheniformis SH003  

Microsoft Academic Search

In order to enhance cell and spore concertration of Bacillus Licheniformis SH003, the optimum fermentation conditions of Bacillus Licheniformis SH003 were studied by single-factor test in shake flasks conditions. The results indicated that culture conditions were: agar volume 40mL, inoculum concentration 10%, initial pH 6.5, growth temperature 35°C, fermentation time 36h and shaker rotating speed 220r\\/min. According to the nutritional

Wenbin Dong; Dawei Zhang; Jie Zhang; Huidong Li; Yuanchang Jin

2010-01-01

270

Optimal Control over the InAs Nanowire Growth for System Integration and their Structural and Transport Properties  

Microsoft Academic Search

We present new fundamental insights into the nucleation and evolution of InAs nanowires (NWs) grown using organo-metallic vapor-phase epitaxy (OMVPE), the correlation of their room temperature transport behavior with their structural properties, and a novel scheme for their integration to Si substrates. We experimentally distinguish, for the first time, two NW growth regimes defined by the direction of In adatom

Shadi A. Dayeh; Darija Susac; Peng Chen; Yi Jing; K. L. Kavanagh; S. S. Lau; E. T. Yu; Deli Wang

2008-01-01

271

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

Microsoft Academic Search

The influence of environmental parameters on mycelial linear growth ofPleurotus ostreatus, P. eryngii, P. pulmonarius, Agrocybe aegerita, Lentinula edodes, Volvariella volvacea andAuricularia auricula-judae was determined in two different nutrient media in a wide range of temperature, forming the basis for the assessment of their\\u000a temperature optimaV. volvacea grew faster at 35°C,P. eryngii at 25°C,P. ostreatus andP. pulmonarius at 30°C,A. aegerita

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

2001-01-01

272

Optimization of director antennas  

Microsoft Academic Search

The optimization of director antennas is considered in the rigorous electrodynamic formulation, and numerical results on such optimization are presented. A software package has been created which makes it possible to optimize (with acceptable machine time) the antenna geometry to achieve a maximum directive gain with a number of directors up to 20. An appropriate selection of vibrator lengths and

A. F. Chaplin; M. D. Buchatskii; M. Iu. Mikhailov

1983-01-01

273

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

274

Gate leakage in AlGaN/GaN HEMTs and its suppression by optimization of MOCVD growth  

NASA Astrophysics Data System (ADS)

Gate-drain current-voltage characteristics in unpassivated AlGaN/GaN high electron mobility transistors (HEMTs) grown by metal-organic chemical vapor deposition (MOCVD) on sapphire substrates were investigated. Under a fixed V/III ratio for AlGaN layer growth, the growth window for getting low gate leakage and good two-dimensional electron gas mobility is narrow. We designed a multi-step growth of the AlGaN for HEMTs, i.e., high-V/III-ratio AlGaN layer starting from the AlGaN/GaN interface, then low-V/III-ratio AlGaN layer, which yielded the best 2DEG mobility and also reduced gate leakage. It was also found that the forward current and reverse current before pinch off can be explained by the thin surface barrier (TSB) model, and the AlGaN layer grown under lower effective V/III ratio shows a larger surface donor density but smaller leaky area.

Zhou, Yugang; Chu, Rongming; Liu, Jie; Chen, Kevin J.; Lau, Kei May

2005-05-01

275

Low-angle silicon-sheet growth. Final technical report, July 1, 1980June 30, 1981  

Microsoft Academic Search

During this period, 48 experimental crystal growth runs were performed to optimize the LASS growth process. Continuous growth of a 9.02 meter long ribbon at an average rate of 20cm\\/min was achieved. This ribbon was 2.5cm wide on the average. Wider ribbon was produced at faster growth rates. The best overall result was a 3.9 meter long ribbon that was

Locher J. W; Bates H. E

1981-01-01

276

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.

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

2011-01-01

277

Confronting the Achievement Gap  

ERIC Educational Resources Information Center

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

Gardner, David

2007-01-01

278

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…

Abowitz, Kathleen Knight

2011-01-01

279

Achieved IPC Performance  

Microsoft Academic Search

Abstract Extensibility can be based on cross - address - space com - munication or on grafting application - speci c modules into the operating system For comparing both ap - proaches, we need to explore the best achievable perfor - mance for both models This paper reports the achieved performance of cross - address - space communication for the

Jochen Liedtke; Kevin Elphinstone; Sebastian Schönberg; Hermann Härtig; Gernot Heiser; Nayeem Islam; Trent Jaeger

1997-01-01

280

General Achievement Trends: Alaska  

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

281

General Achievement Trends: Missouri  

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

282

General Achievement Trends: Arizona  

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

283

General Achievement Trends: Delaware  

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

284

General Achievement Trends: Illinois  

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

285

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

286

General Achievement Trends: Wisconsin  

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

287

General Achievement Trends: Kentucky  

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

288

General Achievement Trends: Oregon  

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

289

General Achievement Trends: Maine  

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

290

General Achievement Trends: Georgia  

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

291

General Achievement Trends: Ohio  

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

292

General Achievement Trends: Colorado  

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

293

General Achievement Trends: Connecticut  

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

294

General Achievement Trends: Hawaii  

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

295

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

296

Experimental study of the kinetically-limited decomposition of ZnGeAs2 and its role in determining optimal conditions for thin film growth  

NASA Astrophysics Data System (ADS)

To understand the thermochemistry and determine the rate limiting steps of ZnGeAs2 thin-film synthesis, experiments were performed to measure the (a) thermal decomposition rate and (b) elemental composition and deposition rate of films produced with pulsed laser deposition (PLD). The decomposition rate is kinetically limited with an activation energy of 1.08±0.05 eV and an evaporation coefficient of ˜10-3. We show that ZnGeAs2 thin film synthesis is a metastable process with the kinetically-limited decomposition rate playing a dominant role at the elevated temperatures needed to attain epitaxy. Our conclusions are in contrast to those of earlier reports that assumed the growth rate is limited by desorption and the resulting low reactant sticking coefficient. The thermochemical analysis presented here can be used to predict optimal conditions for ZnGeAs2 film physical vapor deposition and thermal processing.

Vahidi, M.; Tang, Z. Z.; Tucker, J.; Peshek, T. J.; Zhang, L.; Kopas, C.; Singh, R. K.; van Schilfgaarde, M.; Newman, N.

2012-01-01

297

Optimization of Ligninolytic Enzyme Activity and Production Rate with Ceriporiopsis subvermispora for Application in Bioremediation by Varying Submerged Media Composition and Growth Immobilization Support  

PubMed Central

Response surface methodology (central composite design of experiments) was employed to simultaneously optimize enzyme production and productivities of two ligninolytic enzymes produced by Ceriporiopsis subvermispora. Concentrations of glucose, ammonium tartrate and Polysorbate 80 were varied to establish the optimal composition of liquid media (OLM), where the highest experimentally obtained activities and productivities were 41 U L?1 and 16 U L?1 day?1 for laccase (Lac), and 193 U L?1 and 80 U L?1 day?1 for manganese peroxidase (MnP). Considering culture growth in OLM on various types of immobilization support, the best results were obtained with 1 cm beech wood cubes (BWCM). Enzyme activities in culture filtrate were 152 U L?1 for Lac and 58 U L?1 for MnP, since the chemical composition of this immobilization material induced higher Lac activity. Lower enzyme activities were obtained with polyurethane foam. Culture filtrates of OLM and BWCM were applied for dye decolorization. Remazol Brilliant Blue R (RBBR) was decolorized faster and more efficiently than Copper(II)phthalocyanine (CuP) with BWCM (80% and 60%), since Lac played a crucial role. Decolorization of CuP was initially faster than that of RBBR, due to higher MnP activities in OLM. The extent of decolorization after 14 h was 60% for both dyes.

Babic, Janja; Likozar, Blaz; Pavko, Aleksander

2012-01-01

298

B Cells Are Required for Optimal CD4+ and CD8+ T Cell Tumor Immunity: Therapeutic B Cell Depletion Enhances B16 Melanoma Growth in Mice1  

PubMed Central

B lymphocytes can both positively and negatively regulate cellular immune responses. Previous studies have demonstrated augmented T cell-mediated tumor immunity in genetically B cell-deficient mice, suggesting that therapeutic B cell depletion would enhance tumor immunity. To test this hypothesis and quantify B cell contributions to T cell-mediated anti-tumor immune responses, mature B cells were depleted from wild type adult mice using CD20 mAb prior to syngeneic B16 melanoma tumor transfers. Remarkably, subcutaneous tumor volume and lung metastasis were increased two-fold in B cell-depleted mice. Effector-memory and IFN? or TNF?-secreting CD4+ and CD8+ T cell induction was significantly impaired in B cell-depleted mice with tumors. Tumor Ag-specific CD8+ T cell proliferation was also impaired in tumor-bearing mice that lacked B cells. Thus, B cells were required for optimal T cell activation and cellular immunity in this in vivo non-lymphoid tumor model. While B cells may not have direct effector roles in tumor immunity, impaired T cell activation and enhanced tumor growth in the absence of B cells argues against previous proposals to augment tumor immunity through B cell depletion. Rather, targeting tumor Ags to B cells in addition to dendritic cells is likely to optimize tumor-directed vaccines and immunotherapies.

DiLillo, David J.; Yanaba, Koichi; Tedder, Thomas F.

2013-01-01

299

ACHIEVING SUPERIOR INTERNATIONALIZATION THROUGH STRATEGIC AMBIDEXTERITY  

Microsoft Academic Search

In this paper, I examine the optimal approach to internationalization. Drawing from the ambidexterity literature, I build on the concept of structural ambidexterity and suggest that the optimal approach occurs when firms pursue 'strategic ambidexterity,' which is characterized by simultaneously executing paradoxical strategies of pro-profit and pro-growth. I examine this approach through empirical study based on in-depth field research of

MARY HAN

2007-01-01

300

Hot-Wall MOCVD for Highly Efficient and Uniform Growth of AlN  

Microsoft Academic Search

We demonstrated successful growth of AlN at a temperature of 1200 °C in a set of hot-wall MOCVD systems with the possibility of straightforward scaling up the process on larger wafer areas to meet the demand of device technologies. We outlined several aspects of the carefully optimized design and process parameters with relevance to achievement of a high overall growth

A. Kakanakova-Georgieva; R. R. Ciechonski; U. Forsberg; A. Lundskog; E. Janze?n

2009-01-01

301

Optimization of tetracycline-responsive recombinant protein production and effect on cell growth and ER stress in mammalian cells.  

PubMed

The inducible T-REx system and other inducible expression systems have been developed in order to control the expression levels of recombinant protein in mammalian cells. In order to study the effects of heterologous protein expression on mammalian host behavior, the gene for recombinant Human transferrin (hTf) was integrated into HEK-293 cells and expressed under the control of the T-REx inducible technology (293-TetR-Hyg-hTf) or using a constitutive promoter (293-CMV-hTf). A number of inducible clones with variable expression levels were identified for the T-REx system with levels of hTf for the high expressing clones nearly double those obtained using the constitutive cytomegalovirus (CMV) promoter. The level of transferrin produced was found to increase proportionately with tetracycline concentration between 0 and 1 mug/mL with no significant increases in transferrin production above 1 mug/mL. As a result, the optimal induction time and tetracycline concentrations were determined to be the day of plating and 1 mug/mL, respectively. Interestingly, the cells induced to express transferrin, 293-TetR-Hyg-hTf, exhibited lower viable cell densities and percent viabilities than the uninduced cultures for multiple clonal isolates. In addition, the induction of transferrin expression was found to cause an increase in the expression of the ER-stress gene, BiP, that was not observed in the uninduced cells. However, both uninduced and induced cell lines containing the hTf gene exhibited longer survival in culture than the control cells, possibly as a result of the positive effects of hTf on cell survival. Taken together, these results suggest that the high level expression of complex proteins in mammalian cells can limit the viable cell densities of cells in culture as a result of cellular stresses caused by generating proteins that may be difficult to fold or are otherwise toxic to cells. The application of inducible systems such as the T-REx technology will allow us to optimize protein production while limiting the negative effects that result from these cellular stresses. PMID:15981277

Jones, Jullian; Nivitchanyong, Tarangsri; Giblin, Christina; Ciccarone, Valentina; Judd, David; Gorfien, Stephen; Krag, Sharon S; Betenbaugh, Michael J

2005-09-20

302

Predicting Achievement and Motivation.  

ERIC Educational Resources Information Center

Motivation and nine other factors were measured for 970 students in grades five through eight in a study of factors predicting achievement and predicting motivation. Results are discussed. (Author/MT)

Uguroglu, Margaret; Walberg, Herbert J.

1986-01-01

303

Intelligence and educational achievement  

Microsoft Academic Search

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 achievement (GCSE scores) was 0.81. General intelligence contributed to success on

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

2007-01-01

304

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

305

Optimization of chemical vapor deposition diamond films growth on steel: correlation between mechanical properties, structure, and composition.  

PubMed

In the present work we perform optimization of mechanical and crystalline properties of CVD microcrystalline diamond films grown on steel substrates. A chromium-nitride (Cr-N) interlayer had been previously proposed to serve as a buffer for carbon and iron inter-diffusion and as a matching layer for the widely differing expansion coefficients of diamond and steel. However, adhesion and wear as well as crystalline perfection of diamond films are strongly affected by conditions of both Cr-N interlayer preparation and CVD diamond deposition. In this work we assess the effects of two parameters. The first one is the temperature of the Cr-N interlayer preparation: temperatures in the range of 500 degrees C-800 degrees C were used. The second one is diamond film thickness in the 0.5 microm-2 microm range monitored through variation of the deposition time from approximately 30 min to 2 hours. The mechanical properties of so deposited diamond films were investigated. For this purpose, scratch tests were performed at different indentation loads. The friction coefficient and wear loss were assessed. The mechanical and tribological properties were related to structure, composition, and crystalline perfection of diamond films which were extensively analyzed using different microscopic and spectroscopic techniques. It was found that relatively thick diamond film deposited on the Cr-N interlayer prepared at the temperature similar to that of the CVD process has the best mechanical and adhesion strength. This film was stable without visible cracks around the wear track during all scratch tests with different indentation loads. In other cases, cracking and delamination of the films took place at low to moderate indentation loads. PMID:22097564

Laikhtman, A; Rapoport, L; Perfilyev, V; Moshkovich, A; Akhvlediani, R; Hoffman, A

2011-09-01

306

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

PubMed

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

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

2009-07-01

307

Time Perspective and Causal Attributions for Achievement  

Microsoft Academic Search

This study examines the relation between adolescents' time perspective and attributions for achievement. Temporal aspects of attributions were conceptually linked to individual differences in time perspective. Measures of time perspective (continuity, optimism, pessimism, and utilization) and attributions (ability, effort, context, and luck) independently assessed for success and failure were administered to 215 tenth graders. A canonical analysis extracted one significant

Fredric M. Wolf; Mark L. Savickas

1985-01-01

308

Overcoming the hurdles to achieving glycemic control  

Microsoft Academic Search

Several factors influence diabetes control, and many of these can adversely affect endeavors to obtain optimal glycemic management. For many patients with type 2 diabetes mellitus, the passage of time often results in a loss of responsiveness to medication and a greater difficulty in achieving desired target levels. Although these observations in part reflect a natural progression of diabetes, irrespective

Kenneth M. Shaw

2006-01-01

309

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.

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

2009-01-01

310

The importance of optimal nutrition How an unhealthy and unbalanced diet in the first years of life can have profound effects on growth and development of body and mind - and how to avoid them  

Microsoft Academic Search

9.6 million children die every year from hunger and malnutrition. Malnutrition hinders fetal development, weakens the immune system, impairs physical and mental health, slows thinking, saps energy, stunts growth and leads to infectious disease: optimal nutrition - especially in the early years of life - is of literally vital importance. This book provides concise information to doctors seeking quick guidance

S. Karger AG; Manuela Obrist

2008-01-01

311

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

2012-08-20

312

Achieving IP routing stability with optical bypass  

Microsoft Academic Search

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

Mohit Chamania; Marcel Caria; Admela Jukan

2010-01-01

313

Back to the Basics: In Defense of Achievement (and Achievement Tests) in College Admissions  

ERIC Educational Resources Information Center

|In this article, the author describes the growth and acceptance of achievement tests, such as the Scholastic Aptitude Test (SAT), over the past century, advocating that many SAT claims of equity, uniformity, technical reliability, and prediction, over traditional measures of academic achievement have been found to be illusory. Summarizing a…

Geiser, Saul

2009-01-01

314

Back to the Basics: In Defense of Achievement (and Achievement Tests) in College Admissions  

ERIC Educational Resources Information Center

In this article, the author describes the growth and acceptance of achievement tests, such as the Scholastic Aptitude Test (SAT), over the past century, advocating that many SAT claims of equity, uniformity, technical reliability, and prediction, over traditional measures of academic achievement have been found to be illusory. Summarizing a series…

Geiser, Saul

2009-01-01

315

Minorities Achieving in Nursing.  

ERIC Educational Resources Information Center

|Describes Minorities Achieving in Nursing program, developed at one college to provide a systematic, organized effort specifically targeting the two major minority groups in the Midwest, African Americans and Hispanics. Describes the on-campus recruitment programs for minority students, community outreach activities, results of the recruitment…

Byrd, Carol Y.; Thomas, Marsha J.

1993-01-01

316

Schools Achieving Gender Equity.  

ERIC Educational Resources Information Center

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

Revis, Emma

317

Cognitive Processes and Achievement.  

ERIC Educational Resources Information Center

|For a group of 165 fourth- and fifth-grade students, four achievement test scores were correlated with success on nine tests designed to measure three cognitive functions: sustained attention, successive processing, and simultaneous processing. This experiment was designed in accordance with Luria's model of the three functional units of the…

Hunt, Dennis; Randhawa, Bikkar S.

318

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

319

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

320

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

321

INTELLIGENCE, PERSONALITY AND ACHIEVEMENT.  

ERIC Educational Resources Information Center

|A LONGITUDINAL DEVELOPMENTAL STUDY OF A GROUP OF MIDDLE CLASS CHILDREN IS DESCRIBED, WITH EMPHASIS ON A SEGMENT OF THE RESEARCH INVESTIGATING THE RELATIONSHIP OF ACHIEVEMENT, INTELLIGENCE, AND EMOTIONAL DISTURBANCE. THE SUBJECTS WERE 105 CHILDREN AGED FIVE TO 6.3 ATTENDING TWO SCHOOLS IN MONTREAL. EACH CHILD WAS ASSESSED IN THE AREAS OF…

MUIR, R.C.; AND OTHERS

322

CRCHD - SPN Program Achievements  

Cancer.gov

The most significant achievement of the SPN Program is the establishment of a follow-on program - the Community Networks Program for another 5 years at a commitment of $95 million. With 25 grantees, the CNP is building on the accomplishments of the SPN to reduce cancer health disparities at the community level.

323

Jump Starting Latino Achievement  

ERIC Educational Resources Information Center

Lawmakers have made the closing of racial and ethnic academic achievement gaps an acknowledged priority of the federal No Child Left Behind Act. So far the research has largely explored common factors explaining why Black and Latino students generally lag behind Whites and Asian Americans. Lorretta Chavez, a public school teacher and a doctoral…

Roach, Ronald

2006-01-01

324

Achievements or Disasters?  

ERIC Educational Resources Information Center

|Focuses on policy issues that have affected arts education in the twentieth century, such as: interest in discipline-based arts education, influence of national arts associations, and national standards and coordinated assessment. States that whether the policy decisions are viewed as achievements or disasters are for future determination. (CMK)|

Goodwin, MacArthur

2000-01-01

325

Equalizing Expectations, Achieving Equity.  

ERIC Educational Resources Information Center

|This paper proposes that equity--including gender equity--is an integral part of the agenda of the mathematics standards, and the standards provide an important means of achieving equity. Conventional wisdom on the subject is elaborated upon and professional analysis on equal education in mathematics is provided. Issues in learning and teaching…

Steen, Lynn Arthur

326

Achievable behavior by composition  

Microsoft Academic Search

A fundamental question in systems and control theory concerns the characterization of the set of achievable closed-loop systems for a given plant system and a controller system to be designed. This problem, for example, shows up in assessing the 'limits of performance' of a controlled system. Similar problems have been studied by researchers in automata theory and discrete event systems

A. J. van der Schaft; A. A. Julius

2002-01-01

327

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

328

Minority Achievement Report.  

ERIC Educational Resources Information Center

|This report summarizes the achievements of Prince George's Community College (PGCC) with regard to minority outcomes. Table 1 summarizes the undergraduate enrollment trends for African Americans as well as total minorities from fall 1994 through fall 1998. Both the headcount number of African American students and the proportion of African…

Prince George's Community Coll., Largo, MD. Office of Institutional Research and Analysis.

329

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

330

CEBAF Accelerator Achievements  

NASA Astrophysics Data System (ADS)

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

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

2011-05-01

331

A new optimization based approach to experimental combination chemotherapy.  

PubMed

A new approach towards the design of optimal multiple drug experimental cancer chemotherapy is presented. Once an adequate model is specified, an optimization procedure is used in order to achieve an optimal compromise between after treatment tumor size and toxic effects on healthy tissues. In our approach we consider a model including cancer cell population growth and pharmacokinetic dynamics. These elements of the model are essential in order to allow less empirical relationships between multiple drug delivery policies, and their effects on cancer and normal cells. The desired multiple drug dosage schedule is computed by minimizing a customizable cost function subject to dynamic constraints expressed by the model. However, this additional dynamic wealth increases the complexity of the problem which, in general, cannot be solved in a closed form. Therefore, we propose an iterative optimization algorithm of the projected gradient type where the Maximum Principle of Pontryagin is used to select the optimal control policy. PMID:7612501

Pereira, F L; Pedreira, C E; de Sousa, J B

1995-01-01

332

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.

333

Optimal growth conditions for GdBa2Cu3O7 thin-film coated conductors characterized by polarized Raman scattering spectroscopy  

NASA Astrophysics Data System (ADS)

High temperature superconducting GdBa2Cu3O7 (GdBCO) thin films were grown by pulsed laser ablation. Textured MgO on metal substrates was used as a template for second generation wire applications. Growth conditions of GdBCO thin films were investigated for substrate temperature (Ts) and oxygen partial pressure (PO2) during deposition. Superconducting critical currents of the films were obtained in the films grown at 790-810 °C of Ts and at 100-700 mTorr of PO2. Scanning electron micrographs of the films revealed uniform and well-connected grains with some outgrown structures. X-ray ?-2? scans of the films grown at 810 °C and 300-500 mTorr exhibited c-axis oriented texture. In-plane alignment and c-axis mosaic spread of the films were determined from X-ray ? scans and rocking curves, respectively. Polarized Raman scattering spectroscopy was used to characterize optical phonon modes, oxygen content, cation disorder, and some possible second phases of the films. The Raman spectra of the films with large critical current density showed modes at 326-329 cm-1, 444-447 cm-1, 500-503 cm-1 related to vibration of oxygen atoms. Origin of small peaks near 600 cm-1 will be discussed as well. The information obtained from Raman scattering measurements will be useful for quality control of the conductors as well as optimization of the process conditions.

Kim, G.; Jeong, A. R.; Jo, W.; Park, D. Y.; Cheong, H.; Shin, G. M.; Yoo, S. I.

2010-11-01

334

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

335

Project planning through optimization  

Microsoft Academic Search

Summary form only given as follows. Projects exposed to an uncertain environment must deal with effective integration of various planning elements and optimization of project parameters. Time cost and quality are the prime objectives of a project that are to be optimized to fulfil the objective of project achievement. Moreover, in uncertain environments, there exists a lot of other conflicting

P. K. Dey; S. Mukherjee; A. Bhattacharya

1997-01-01

336

Use of culture geometry to control hypoxia-induced vascular endothelial growth factor secretion from adipose-derived stem cells: optimizing a cell-based approach to drive vascular growth.  

PubMed

Adipose-derived stem cells (ADSCs) possess potent angiogenic properties and represent a source for cell-based approaches to delivery of bioactive factors to drive vascularization of tissues. Hypoxic signaling appears to be largely responsible for triggering release of these angiogenic cytokines, including vascular endothelial growth factor (VEGF). Three-dimensional (3D) culture may promote activation of hypoxia-induced pathways, and has furthermore been shown to enhance cell survival by promoting cell-cell interactions while increasing angiogenic potential. However, the development of hypoxia within ADSC spheroids is difficult to characterize. In the present study, we investigated the impact of spheroid size on hypoxia-inducible transcription factor (HIF)-1 activity in spheroid cultures under atmospheric and physiological oxygen conditions using a fluorescent marker. Hypoxia could be induced and modulated by controlling the size of the spheroid; HIF-1 activity increased with spheroid size and with decreasing external oxygen concentration. Furthermore, VEGF secretion was impacted by the hypoxic status of the culture, increasing with elevated HIF-1 activity, up to the point at which viability was compromised. Together, these results suggest the ability to use 3D culture geometry as a means to control output of angiogenic factors from ADSCs, and imply that at a particular environmental oxygen concentration an optimal culture size for cytokine production exists. Consideration of culture geometry and microenvironmental conditions at the implantation site will be important for successful realization of ADSCs as a pro-angiogenic therapy. PMID:23668629

Skiles, Matthew L; Sahai, Suchit; Rucker, Lindsay; Blanchette, James O

2013-06-26

337

Achieving closure at Fernald  

SciTech Connect

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

Bradburne, John; Patton, Tisha C.

2001-02-25

338

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…

McCabe, Molly

2010-01-01

339

Growth of Al x Ga 1? x N (0 < = x < = 0.2) and fabrication of AlGaN\\/GaN superlattice by RF-source MBE  

Microsoft Academic Search

Based on the two-step growth, GaN and AlGaN on sapphire (0001) were grown by MBE using an RF-source. We have attained a very flat growing surface by optimizing growth conditions both for the buffer layer and the main growth. We also grew AlGaN\\/GaN superlattices to demonstrate the flatness achieved on the growth surface. From X-ray diffraction and transmission electron microscopy

Kazuhiko Nozawa; Narihiko Maeda; Yoshiro Hirayama; Naoki Kobayashi

1998-01-01

340

Achievement Goals and Achievement Emotions: A Meta-Analysis  

ERIC Educational Resources Information Center

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

Huang, Chiungjung

2011-01-01

341

Entrepreneur achievement. Liaoning province.  

PubMed

This paper reports the successful entrepreneurial endeavors of members of a 20-person women's group in Liaoning Province, China. Jing Yuhong, a member of the Family Planning Association at Shileizi Village, Dalian City, provided the basis for their achievements by first building an entertainment/study room in her home to encourage married women to learn family planning. Once stocked with books, magazines, pamphlets, and other materials on family planning and agricultural technology, dozens of married women in the neighborhood flocked voluntarily to the room. Yuhong also set out to give these women a way to earn their own income as a means of helping then gain greater equality with their husbands and exert greater control over their personal reproductive and social lives. She gave a section of her farming land to the women's group, loaned approximately US$5200 to group members to help them generate income from small business initiatives, built a livestock shed in her garden for the group to raise marmots, and erected an awning behind her house under which mushrooms could be grown. The investment yielded $12,000 in the first year, allowing each woman to keep more than $520 in dividends. Members then soon began going to fairs in the capital and other places to learn about the outside world, and have successfully ventured out on their own to generate individual incomes. Ten out of twenty women engaged in these income-generating activities asked for and got the one-child certificate. PMID:12287775

Zhao, R

1994-03-01

342

Academy of Achievement  

NSDL National Science Digital Library

LetÂs face it: economia to those great heroes of the past are nothing new, and some might believe that there are too many out there in the first place. The Academy of Achievement website disproves this idea with its well-thought out tributes to those truly unique individuals who have made substantive contributions in the arts, the sciences, and a number of other areas of human endeavor. As its site notes, it is a Âmuseum of living historyÂ, and a cursory glance over those they have honored would seem to bear witness to this statement. First-time visitors will definitely want to take a look at the ÂAchiever GalleryÂ, where they can view profiles and biographies of such personages as Jonas Salk, Rosa Parks, and Willie Mays. The real icing on the cake here is the interview section for each profiled member, as it truly allows for a number of interesting and evocative insights into their motivations and life trajectories. The site is rounded out with a ÂFor Teachers section, which offers a number of pedagogical tools specifically aimed towards those in the teaching profession.

343

Achieving Energy Efficiency via Drowsy Transmission in Cognitive Radio  

Microsoft Academic Search

Energy efficiency is increasingly important for wireless communication systems. An optimization policy for cognitive radio communication systems is derived by employing dynamic programming, thus improving the energy efficiency via drowsy transmission. An alternative Q-learning approach is introduced when the environment model is unknown. Numerical simulation results demonstrate that our proposed optimization is effective. Significant performance gain is achieved especially when

Kun Zheng; Husheng Li

2010-01-01

344

Earning the Stamp of Approval: How To Achieve Optimal Usability.  

ERIC Educational Resources Information Center

Describes the redesign of the Web site at the virtual library of the NIST (National Institute of Standards and Technology). Discusses usability problems with the original site, including navigation difficulties; focus groups to determine user needs; usability testing for the new Web site; and the importance of customer input. (LRW)

Makar, Susan

2003-01-01

345

Using Knowledge to Optimally Achieve Coordination in Distributed Systems  

Microsoft Academic Search

Abstract Fundamental,to many,disciplines is the problem,of coordinating,the actions of a group,of independent agents. Researchers,in distributed computing systems have long endeavored,to find efficient solutions to a variety of problems involving coordination among the processors in such a system. Recently, processor knowledge has been used to characterize such solution and to derive more,efficient ones.,Most this work,has concentrated,on the relationship between,common,knowledge and simultaneous

Gil Neiger; Rida A. Bazzi

1992-01-01

346

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

347

Denver airport pumping systems achieve optimal [Delta] T's  

SciTech Connect

This article describes how the pumping and generating systems at the new Denver Airport operate efficiently with the user loops in the buildings producing design temperature rise at all load levels. Fifteen miles east of Denver's Stapleton International Airport lies the newly completed Denver International Airport (DIA)--the world's largest and most high-tech airport. Besides being one of the largest construction projects in the works, it has many of the latest technical innovations available. Of particular interest to the HVAC industry is the design of the heating and cooling water systems. These systems provide environmental cooling and heating water to the three concourses, the airport office building, and the main terminal. The mechanical engineers for the project were all from the Denver area. The central plant design was the work of Behrent Engineering Co.; the three concourses were designed by Swanson-Rink Associates; and the main terminal and administrative office building were designed by Abeyta Engineering Consultants. The overall system concept was developed during the initial design phase by engineers from these firms, members of the DIA staff, and application engineers from several manufacturers.

Mannion, G.F.; Krist, G.D. (BRDG-TNDR Corp., Fort Lauderdale, FL (United States))

1994-07-01

348

Using scheduler information to achieve optimal barrier synchronization performance  

Microsoft Academic Search

Parallel programs frequently use barriers to synchronize successive steps in an algorithm. In the presence of multiprogramming the choice of spinning versus blocking barriers can have a significant impact on performance. We demonstrate how competitive spinning techniques previously designed for locks can be extended to barriers, and we evaluate their performance. We design an additional competitive spinning technique that adapts

Leonidas Kontothanassis; Robert W. Wisniewski

1993-01-01

349

NUMERICAL OPTIMIZATION OF CRUSIFORM SPECIMENS GEOMETRY FOR PERFORMED THROUGH AND SEMI - ELLIPTICAL FATIGUE CRACKS UNDER BIAXIAL CICLIC LOADS AND CRACK GROWTH SIMULATION  

Microsoft Academic Search

Several variants for the stress -state calculation were considered on the basis of the FEM analysis to optimize the cruciform specimens sizes for tests under biaxial cyclic loads for through an d semi - elliptical cracks. The optimization was performed to locate in the center part of the specimen uniform biaxial stress-state for the specimen thickness 2mm, 5mm, and 10mm.

A. A. Shaniavski

350

Fine-tuning the lipogenic/lipolytic balance to optimize the metabolic requirements of cancer cell growth: molecular mechanisms and therapeutic perspectives.  

PubMed

Evolving evidence suggest that metabolic requirements for cell proliferation are identical in all normal and cancer cells. HER2 oncogene-overexpressors, a highly aggressive subtype of human cancer cells, constitute one of the best examples of how malignant cells maximize their ability to acquire and metabolize nutrients in a manner conductive to proliferation rather than efficient ATP production. HER2-overexpressors optimize their requirements of rapid cancer cell growth by fine-tuning a double [lipogenic/lipolytic]-edged metabolic sword. On the one edge, HER2 oncogene overexpression triggers redundant signaling cascades to ensure that all the major enzymes involved in de novo fatty acid (FA) synthesis will facilitate aerobic glycolysis instead of oxidative phosphorylation for energy production (Warburg effect). HER2 also establishes a positive bidirectional relationship with the key lipogenic enzyme Fatty Acid Synthase (FASN) that rapidly senses and respond to any disturbance in the flux of lipogenic substrates (e.g. NADPH and acetyl-CoA) and lipogenesis end-products (i.e. palmitate). On the other edge, HER2 overexpression arranges detoxifying mechanisms by upregulating PPARgamma, a well established positive regulator role of adipogenesis and lipid storage in cell types with active lipid metabolism. PPARgamma establishes a lipogenesis/lipolysis joining-point that enables HER2-positive cancer cells to avoid endogenous palmitate toxicity while securing palmitate into fat stores to avoid palmitate feedback on FASN functioning. The ability of HER2 to supercharge lipogenesis (by activating regulatory circuits that activate and fuel the lipogenic enzyme FASN) while averting lipotoxicity (by promoting conversion and storage of excess FAs to triglycerides in a PPARgamma-dependent manner) supports the notion that best adapted cancer phenotypes are addicted to oncogenic lipid metabolism for cell proliferation and survival. It is conceptually attractive to assume that we can crash HER2-driven rapid cell proliferation by inhibiting "motor refueling" (upon blockade of lipogenic enzymes), by losing the "lipolytic brake" (upon blockade of PPARgamma) and/or by sticking the "lipogenic gas pedal" (upon supplementation with dietary FAs). PMID:19782152

Menendez, Javier A

2009-09-24

351

Achievable Transmission Capacity of Secondary System in Cognitive Radio Networks  

Microsoft Academic Search

This paper evaluates the achievable transmission capacity of the secondary system in cognitive radio networks, defined by the spatial density of successful transmissions while guaranteeing the target outage probabilities of the secondary and the primary systems. By using stochastic geometry, the effects of the spatial densities and the transmission powers on the achievable transmission capacity is presented. Subsequently, the optimal

Jemin Lee; Sungmook Lim; Jeffrey G. Andrews; Daesik Hong

2010-01-01

352

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

353

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…

Ediger, Marlow

2011-01-01

354

The Development of Science Achievement in Middle and High SchoolrIndividual Differences and School Effects  

Microsoft Academic Search

Using data from the Longitudinal Study of American Youth (LSAY), hierarchical linear models (HLMs) were used to model the growth of student science achievement in three areas (biology, physical science, and environmental science) during middle and high school. Results showed significant growth in science achievement across all areas. The growth was quadratic across all areas, with rapid growth at the

Xin Ma; Jesse L. M. Wilkins

2002-01-01

355

Longitudinal effects of educational expectations and achievement attributions on adolescents' academic achievements.  

PubMed

This study used nationwide data from the Taiwan Education Panel Survey (TEPS) to examine the longitudinal effects of educational expectations and achievement attributions on the academic achievements of adolescents. The sample included 2,000 Taiwanese secondary school students, each of whom completed three waves of questionnaires and cognitive tests: the first in grade 7 (in 2001), the second in grade 9 (in 2003), and the third in grade 11 (in 2005). Through multilevel longitudinal analysis, the results showed: (1) educational expectations accounted for a moderate amount of the variance in academic achievements; (2) students with high educational expectations and effort attribution exhibited higher growth rates in their academic achievements; and (3) studentswith lower educational expectations and those attributing success to others showed significantly fewer academic achievements and significantly lower growth rates in such achievements. The results demonstrated that adolescents' educational expectations and achievement attributions play crucial roles in the long-term course of academic accomplishments. Implications for educational practice and further studies are also discussed. PMID:20432607

Liu, Kun-Shia; Cheng, Ying-Yao; Chen, Yi-Ling; Wu, Yuh-Yih

2009-01-01

356

Achievement goals and intrinsic motivation: Coherence, concordance, and achievement orientation  

Microsoft Academic Search

Two studies examined the effects on intrinsic motivation of pursuing lower-order target goals in an achievement context emphasizing a performance purpose goal. The purpose goal was theorized to be concordant with intrinsic needs for individuals high in achievement motivation (HAMs), but not for individuals low in achievement motivation (LAMs). Target goals that were coherent with the overall purpose goal were

Amanda M. Durik; Judith M. Harackiewicz

2003-01-01

357

Influence of pesticides on the growth of cyanobacteria.  

PubMed

Two unicellular and two filamentous cyanobacteria (blue-green algae) were exposed under conditions optimal for photoautotrophic growth to eleven pesticides. Low concentrations (0.01 to 5 ppm) of diuron, atrazine, and paraquat inhibited growth. With MCPA, MCPP, 2,4-D, milstem and ethrel, marked inhibitory effects were achieved only at concentrations above 100 ppm. Growth was inhibited by glyphosate, DDT, and thiram at intermediate concentrations. In some cases, the effective concentration of the pesticide varied considerably with the organism tested. PMID:120640

Hutber, G N; Rogers, L J; Smith, A J

1979-01-01

358

Improvement of autohydrogenotrophic nitrite reduction rate through optimization of pH and sodium bicarbonate dose in batch experiments  

Microsoft Academic Search

Accumulation of nitrite intermediate in autohydrogenotrophic denitrification process has been a challenging difficulty to tackle. This study showed that further growth of “true denitrifying” bacteria and adaptation to nitrite led to a faster reduction of nitrite than nitrate as a solution to circumvent nitrite accumulation. Moreover, two effective parameters namely pH and bicarbonate dose were optimized in order to achieve

Shahin Ghafari; Masitah Hasan; Mohamed Kheireddine Aroua

2009-01-01

359

Optimization of Campylobacter growth conditions for further identification by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).  

PubMed

Growth conditions - including growth medium and incubation temperature - may influence the identification of Campylobacter by MALDI-TOF MS. For each bacterial species, medical microbiologists should be aware of such potential influences on spectral data before analyzing and interpreting MALDI-TOF MS results. PMID:23811211

Martiny, Delphine; Visscher, Alain; Catry, Boudewijn; Chatellier, Sonia; Vandenberg, Olivier

2013-06-26

360

Model based optimization of high cell density cultivation of nitrogen-fixing cyanobacteria.  

PubMed

In the present study, fed-batch cultivation of Cyanothece sp. ATCC 51142, a known hydrogen producer, was optimized for maximizing biomass production. Decline in growth of this organism in dense cultures was attributed to increased substrate consumption for maintenance and respiration, and photolimitation due to self shading. A model incorporating these aspects was developed, and by using control vector parameterization (CVP), substrate feeding recipe was optimized to achieve 12-fold higher biomass concentration. The optimization results were verified experimentally on shake flask and bioreactor. The latter resulted in greater exponential growth rate possibly by overcoming photolimitation by simulating flashing light effect. Such a strategy can be readily applied for mixotrophic cultivation of cyanobacterial cultures in the first stage followed by photoautotrophic growth at the production stage. PMID:24047683

Alagesan, Swathi; Gaudana, Sandeep B; Krishnakumar, S; Wangikar, Pramod P

2013-08-31

361

Learning optimal embedded cascades.  

PubMed

The problem of automatic and optimal design of embedded object detector cascades is considered. Two main challenges are identified: optimization of the cascade configuration and optimization of individual cascade stages, so as to achieve the best tradeoff between classification accuracy and speed, under a detection rate constraint. Two novel boosting algorithms are proposed to address these problems. The first, RCBoost, formulates boosting as a constrained optimization problem which is solved with a barrier penalty method. The constraint is the target detection rate, which is met at all iterations of the boosting process. This enables the design of embedded cascades of known configuration without extensive cross validation or heuristics. The second, ECBoost, searches over cascade configurations to achieve the optimal tradeoff between classification risk and speed. The two algorithms are combined into an overall boosting procedure, RCECBoost, which optimizes both the cascade configuration and its stages under a detection rate constraint, in a fully automated manner. Extensive experiments in face, car, pedestrian, and panda detection show that the resulting detectors achieve an accuracy versus speed tradeoff superior to those of previous methods. PMID:22213762

Saberian, Mohammad Javad; Vasconcelos, Nuno

2012-10-01

362

Optimization of air-assisted CVD growth of vertically-aligned ZnO nanowires, guided by structural analysis using X-ray scattering  

NASA Astrophysics Data System (ADS)

ZnO nanowires (ZNWs) are of significant interest for applications ranging from optical sensors to vibrational energy harvesters, due to properties including UV photoluminescence and piezoelectricity. We have studied low-pressure growth of ZNWs using a vapor transport method in air flowing within a tube furnace, giving vertically-aligned ZNW arrays on sapphire substrates seeded by Au catalysts. The growth rate and the average length of ZNWs depend on the flow rate of air and the total growth time, while multiple parameters such as catalyst thickness, pressure, and temperature also interdependently affect the ZNW characteristics. Grazing incidence small-angle X-ray scattering (GI-SAXS) measurements enable non-destructive quantification of ZNW diameter and alignment. By fitting GI-SAXS images using analytical models of the array as a population of solid cylinders having a Gaussian diameter distribution, we establish precise relationships between the structural characteristics and the growth conditions; for example, we determine rates of radial growth and size distribution broadening in comparison to axial growth. Control of the temperature gradient within the furnace also enables growth of well-aligned arrays at substrate temperatures as low as 600 ^oC.

Ok, Jong G.; Hart, A. John

2009-03-01

363

Use of a D-optimal design with constrains to quantify the effects of the mixture of sodium, potassium, calcium and magnesium chloride salts on the growth parameters of Saccharomyces cerevisiae  

Microsoft Academic Search

The combined effect of NaCl, KCl, CaCl2, and MgCl2 on the water activity (a\\u000a w) and the growth parameters of Saccharomyces cerevisiae was studied by means of a D-optimal mixture design with constrains (total salt concentrations ? 9.0%, w\\/v). The a\\u000a w was linearly related to the concentrations of the diverse salts; its decrease, by similar concentrations of salts, followed\\u000a the order

J. Bautista-Gallego; F. N. Arroyo-López; A. Chiesa; M. C. Durán-Quintana; A. Garrido-Fernández

2008-01-01

364

Oocyte growth in vitro: potential model for studies of oocyte–granulosa cell interactions  

Microsoft Academic Search

Various factors such as gonadotrophins, growth factors, and steroid hormones play important roles in the regulation of oocyte\\/follicular\\u000a growth in mammalian ovaries. In addition to these factors, there is a bidirectional interaction between oocytes and granulosa\\u000a cells that is essential for achieving optimal oocyte developmental competence. Oocytes play a key role in this interaction\\u000a by secreting paracrine factors that alter

Yuji Hirao

365

Achieving \\  

Microsoft Academic Search

Science education in the Australian primary school curriculum is a relatively rare event. Several studies over the past twenty five years have all reported disappointingly low amounts of science being taught and the reluctance of primary school teachers to make science a priority in their teaching. Similar outcomes have been reported for environmental education. Even though primary aged children are

Annette Gough

2004-01-01

366

Perspectives on Middle Level Student Achievement. Rethinking Student Achievement.  

ERIC Educational Resources Information Center

|Discusses the trend toward increased standardization in examining student learning and achievement. Maintains that the crux of middle-level curriculum reform involves a contextual notion of achievement. Asserts that working out conceptions of middle-level student learning and the work of teachers making professional judgments about what…

Arhar, Joanne M.

2003-01-01

367

Achievement Performance Related to Achievement Motivation and Test Anxiety  

ERIC Educational Resources Information Center

Achievement motivation. test anxiety, and performance on a standardized reading test were assessed among males and females in the seventh and eighth grades. For both male and female Ss, reading performance was positively related to achievement motivation and negatively related to test anxiety. (Author)

Kestenbaum, Joel M.; Weiner, Bernard

1970-01-01

368

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

369

Content-specific achievement motives  

Microsoft Academic Search

The assessment of achievement motives has mostly been realised in a broad manner, disregarding potential differences between content-specific achievement motives (e.g., regarding different school subjects). A sample of N=1084 German high-school students (grades 9 and 10, mean age: 15years) responded to a questionnaire in which the achievement motives “hope of success” and “fear of failure” were assessed (a) in general

Jörn R. Sparfeldt; Detlef H. Rost

2011-01-01

370

Increased Plasma Vascular Endothelial Growth Factor (VEGF) as a Surrogate Marker for Optimal Therapeutic Dosing of VEGF Receptor2 Monoclonal Antibodies  

Microsoft Academic Search

A major obstacle compromising the successful application of many of the new targeted anticancer drugs, including angiogenesis inhibitors, is the em- piricism associated with determining an effective biological\\/therapeutic dose because many of these drugs express optimum therapeutic activity below the maximum tolerated dose, if such a dose can be defined. Hence, surrogate markers are needed to help determine optimal dosing.

Guido Bocci; Shan Man; Shane K. Green; Giulio Francia; John M. L. Ebos; Jeanne M. du Manoir; Adina Weinerman; Urban Emmenegger; Li Ma; Philip Thorpe; Andrew Davidoff; James Huber; Daniel J. Hicklin; Robert S. Kerbel

2004-01-01

371

Evaluation of BacT/Alert 3D automated unit for detection of nontuberculous mycobacteria requiring incubation at 30 degrees C for optimal growth.  

PubMed

The reliability of the BacT/Alert 3D unit for automated detection of nontuberculous mycobacteria (NTM) that grow optimally at 30 °C was assessed. This system reliably maintained a temperature of 30 °C and detected 50% of the clinical NTM strains (5 Mycobacterium marinum and 3 Mycobacterium gordonae strains) faster than 37 °C culture. PMID:21543566

Alfa, Michelle J; Manickam, Kanchana; Sepehri, Shadi; Sitter, Denise; Lenton, Pat

2011-05-04

372

Evaluation of BacT/Alert 3D Automated Unit for Detection of Nontuberculous Mycobacteria Requiring Incubation at 30?C for Optimal Growth ?  

PubMed Central

The reliability of the BacT/Alert 3D unit for automated detection of nontuberculous mycobacteria (NTM) that grow optimally at 30°C was assessed. This system reliably maintained a temperature of 30°C and detected 50% of the clinical NTM strains (5 Mycobacterium marinum and 3 Mycobacterium gordonae strains) faster than 37°C culture.

Alfa, Michelle J.; Manickam, Kanchana; Sepehri, Shadi; Sitter, Denise; Lenton, Pat

2011-01-01

373

Achieving developmental synchrony in young children with hearing loss.  

PubMed

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

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

2009-12-01

374

Transmission line optimization  

Microsoft Academic Search

Transmission line designs have been optimized for many years through comparative estimates of the present worth of revenue required (PWRR), in order to achieve design performance at minimum cost. The method has most commonly been used for conductor selection, but can obviously be applied to other parameters as well, although the economic returns from these other parameters are largely unknown.

Ian S. Grant; Roger E. Clayton

1987-01-01

375

Achievement Goals and Intrinsic Motivation  

Microsoft Academic Search

Two experiments investigated the effects of achievement goals on intrinsic motivation for an enjoyable pinball game. Study 1 manipulated Ss' performance (demonstrating ability) and mastery (developing one's skills) achievement goals and contrasted them with a neutral control group. Study 2 replicated Study 1 and extended it by additionally providing (or not) Ss with positive, goal-relevant feedback. Results were consistent across

Judith M. Harackiewicz; Andrew J. Elliot

1993-01-01

376

Family Status and School Achievement.  

ERIC Educational Resources Information Center

This study tested the hypothesis that there is no significant difference in reading achievement among children in grades 2 through 5 related to family structure. Researchers administered the Stanford Achievement Test to 119 students in an Alabama city suburban school system. Of the sample, 69 children lived in intact families and 50 lived in…

Chalker, Rhoda N.; Horns, Virginia

377

Raising Boys' Achievement in Schools.  

ERIC Educational Resources Information Center

This book offers insights into the range of strategies and good practice being used to raise the achievement of boys. Case studies by school-based practitioners suggest ideas and measures to address the issue of achievement by boys. The contributions are: (1) "Why the Likely Lads Lag Behind" (Kevan Bleach); (2) "Helping Boys Do Better in Their…

Bleach, Kevan, Ed.

378

General Achievement Trends: West Virginia  

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

379

General Achievement Trends: New Mexico  

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

380

General Achievement Trends: North Dakota  

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

381

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

382

Achievement in Writing Geometry Proofs.  

ERIC Educational Resources Information Center

|In 1981 a nationwide assessment of achievement in writing geometry proofs was conducted by the Cognitive Development and Achievement in Secondary School Geometry project. Over 1,500 students in 11 schools in 5 states participated. This paper describes the sample, instruments, grading procedures, and selected results. Results include: (1) at the…

Senk, Sharon L.

383

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

384

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

385

Television Viewing and School Achievement.  

ERIC Educational Resources Information Center

|Examined effects of amount of television viewing, socioeconomic status, study habits, and home environment on sixth-graders' achievement in reading, mathematics, and written expression. Found, among other results, that students who viewed more than six hours of television per day had sharply lower achievement scores in all three content areas.…

Fetler, Mark

1984-01-01

386

Optimization study of metal-organic chemical vapor deposition of ZnO on sapphire substrate  

NASA Astrophysics Data System (ADS)

Metal-organic chemical vapor deposition (MOCVD) of ZnO with dimethylzinc (DMZn) and tert-butanol (t-BuOH) as Zn and oxygen precursors has been investigated and optimized in this work. Growth experiments show hydrogen addition, usually used to suppress carbon incorporation, should be kept at a low concentration due to its strong etching effect on ZnO. We found that reduction of hydrogen concentration also results in smoother films. Growth at a reactor pressure of 4-8 kPa resulted in smoother films as compared to growth at 2 kPa, and growth temperature of 470 °C is also observed to result in smoother films, while fully suppressing gas phase pre-reactions. A low growth rate also helps to obtain smooth surface morphology, which is helpful to achieve improved crystal quality of the subsequent high temperature epilayer. The optimized growth parameters provided by this work are helpful for achieving high quality ZnO epilayer growth on sapphire substrates.

Zhu, Guangyao; Gu, Shulin; Zhu, Shunming; Huang, Shimin; Gu, Ran; Ye, Jiandong; Zheng, Youdou

2012-06-01

387

How much detail and accuracy is required in plant growth sub-models to address questions about optimal management strategies in agricultural systems?  

PubMed Central

Background and aims Simulations that integrate sub-models of important biological processes can be used to ask questions about optimal management strategies in agricultural and ecological systems. Building sub-models with more detail and aiming for greater accuracy and realism may seem attractive, but is likely to be more expensive and time-consuming and result in more complicated models that lack transparency. This paper illustrates a general integrated approach for constructing models of agricultural and ecological systems that is based on the principle of starting simple and then directly testing for the need to add additional detail and complexity. Methodology The approach is demonstrated using LUSO (Land Use Sequence Optimizer), an agricultural system analysis framework based on simulation and optimization. A simple sensitivity analysis and functional perturbation analysis is used to test to what extent LUSO's crop–weed competition sub-model affects the answers to a number of questions at the scale of the whole farming system regarding optimal land-use sequencing strategies and resulting profitability. Principal results The need for accuracy in the crop–weed competition sub-model within LUSO depended to a small extent on the parameter being varied, but more importantly and interestingly on the type of question being addressed with the model. Only a small part of the crop–weed competition model actually affects the answers to these questions. Conclusions This study illustrates an example application of the proposed integrated approach for constructing models of agricultural and ecological systems based on testing whether complexity needs to be added to address particular questions of interest. We conclude that this example clearly demonstrates the potential value of the general approach. Advantages of this approach include minimizing costs and resources required for model construction, keeping models transparent and easy to analyse, and ensuring the model is well suited to address the question of interest.

Renton, Michael

2011-01-01

388

Achieving Balance in Reading Assessment  

Microsoft Academic Search

his is an era of great promise and great challenge for reading assessment. Our evolving knowledge of reading and reading assessment helps us conceptualize students' reading growth and determine appropriate assessments to measure and describe that growth. An array of reading assessment materials and procedures, including teacher questioning, performance assessment, portfolio assessment, checklists, reading inventories, and quizzes and tests, can

389

Dextrous hand grasping force optimization  

Microsoft Academic Search

A key goal in dextrous robotic hand grasping is to balance external forces and at the same time achieve grasp stability and minimum grasping energy by choosing an appropriate set of internal grasping forces. Since it appears that there is no direct algebraic optimization approach, a recursive optimization, which is adaptive for application in a dynamic environment, is required. One

Martin BUSS; Hideki Hashimoto; John B. Moore

1996-01-01

390

The Achievement Ideology and Whiteness: "Achieving Whiteness" or "Achieving Middle Class?"  

ERIC Educational Resources Information Center

|Over the past few decades, social reproduction theorists have criticized achievement ideology as a dominant and dominating myth that hides the true nature of class immobility. Social reproductionists' primary criticism of achievement ideology is that it blinds the working class, regardless of race or gender, to the possibilities of collective…

Allen, Ricky Lee

391

Mathematics anxiety and mathematics achievement  

NASA Astrophysics Data System (ADS)

This paper is a distillation of the major result from the 1998 Ph.D. thesis of the late David Wither. It details a longitudinal study over five years of the relationship between mathematics anxiety and mathematics achievement. It starts from the already well documented negative correlation between the two, and seeks to establish one of the three hypotheses—that mathematics anxiety causes an impairment of mathematics achievement; that lack of mathematics achievement causes mathematics anxiety; or that there is a third underlying cause of the two.

Sherman, Brian F.; Wither (Post.), David P.

2003-09-01

392

Optimizing influenza vaccine distribution.  

PubMed

The criteria to assess public health policies are fundamental to policy optimization. Using a model parametrized with survey-based contact data and mortality data from influenza pandemics, we determined optimal vaccine allocation for five outcome measures: deaths, infections, years of life lost, contingent valuation, and economic costs. We find that optimal vaccination is achieved by prioritization of schoolchildren and adults aged 30 to 39 years. Schoolchildren are most responsible for transmission, and their parents serve as bridges to the rest of the population. Our results indicate that consideration of age-specific transmission dynamics is paramount to the optimal allocation of influenza vaccines. We also found that previous and new recommendations from the U.S. Centers for Disease Control and Prevention both for the novel swine-origin influenza and, particularly, for seasonal influenza, are suboptimal for all outcome measures. PMID:19696313

Medlock, Jan; Galvani, Alison P

2009-08-20

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

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

2013-06-27

395

Student Health and Academic Achievement  

MedlinePLUS

... The Association Between School-Based Physical Activity, Including Physical Education, and Academic Performance [pdf 2.5M] (Full report) ... M, Drown DR, Kohl III HW, Dietz WH. Physical education and academic achievement in elementary school: data from ...

396

Achievement Motivation in Welfare Youth.  

National Technical Information Service (NTIS)

The aim of this project was to investigate achievement motivation in youth participating in the Aid to Families with Dependent Children (AFDC) program. Three interrelated issues were studied: (1) the relationship between length of time on public assistanc...

E. V. Mech

1977-01-01

397

Accounting for China's Growth  

Microsoft Academic Search

China has achieved impressive growth over the last three decades. However, there has been debate over the sources of the growth, and the role of the intensive versus extensive margin. Growth accounting exercises at the aggregate level (Rawski and Perkins, 2008; Bosworth and Collins, 2008) suggest an equal role for both. For the non-agricultural sector, there have been doubts about

Loren Brandt; Xiaodong Zhu

2009-01-01

398

Privatization in Education: A Growth Curve Analysis of Achievement.  

ERIC Educational Resources Information Center

The purpose of this study was to determine whether the students who attended one elementary school in Miami-Dade County, Florida, run by The Edison Project (Edison Schools, Inc.) made greater academic progress than comparable students who attended other district schools. The paper provides a longitudinal examination of the students' academic…

Shay, Sally A.; Gomez, Joseph J.

399

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

400

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

401

The celA Gene, Encoding a Glycosyl Hydrolase Family 3 ?-Glucosidase in Azospirillum irakense, Is Required for Optimal Growth on Cellobiosides  

PubMed Central

The CelA ?-glucosidase of Azospirillum irakense, belonging to glycosyl hydrolase family 3 (GHF3), preferentially hydrolyzes cellobiose and releases glucose units from the C3, C4, and C5 oligosaccharides. The growth of a ?celA mutant on these cellobiosides was affected. In A. irakense, the GHF3 ?-glucosidases appear to be functional alternatives for the GHF1 ?-glucosidases in the assimilation of ?-glucosides by other bacteria.

Faure, Denis; Henrissat, Bernard; Ptacek, David; Bekri, My Ali; Vanderleyden, Jos

2001-01-01

402

Optimal pollination environment of tetraploid ginger ( Zingiber officinale Roscoe) evaluated by in vitro pollen germination and pollen tube growth in styles  

Microsoft Academic Search

Pollen germination percentages in vitro of a tetraploid ginger (Zingiber officinale Roscoe), ‘4×Sanshu’, tended to be highest at around 20°C. Pollen tube growth in the styles was greatly enhanced at 17°C, i.e., pollen tubes penetrated into the entire stylar length in 66.7% of the styles used. Pollen stored for at least 3h under 40–80% relative humidity (RH) almost completely lost

Shinichi Adaniya

2001-01-01

403

Optimizing Conditions for the Growth ofLactobacillus casei YIT 9018 in Tryptone-Yeast Extract-Glucose Medium by Using Response Surface Methodology  

Microsoft Academic Search

This study was undertaken to find optimum conditions of tryptone, yeast extract, glucose, Tween 80, and incubation temperature for the growth ofLactobacillus caseiYIT 9018 and to assess the effects of these factors by use of response surface methodology. A central composite design was used as an experimental design for allocation of treatment combinations. A second-order polynomial regression model, which was

SEJONG OH; SUNGSUE RHEEM; JAEHUN SIM; SANGKYO KIM; ANDYOUNGJIN BAEK

1995-01-01

404

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

405

The method of p -harmonic approximation and optimal interior partial regularity for energy minimizing p -harmonic maps under the controllable growth condition  

Microsoft Academic Search

In this paper, we are concerned with the partial regularity for the weak solutions of energy minimizing p-harmonic maps under the controllable growth condition. We get the interior partial regularity by the p-harmonic approximation method together with the technique used to get the decay estimation on some Degenerate elliptic equations\\u000a and the obstacle problem by Tan and Yan. In particular,

Shu-Hong Chen; Zhong Tan

2007-01-01

406

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

407

Growth inhibitory activity of gutta-percha points containing root canal medications on common endodontic bacterial pathogens as determined by an optimized quantitative in vitro assay.  

PubMed

Gutta-percha points containing calcium hydroxide, zinc oxide (ZnO), a mixture of ZnO and chlorhexidine (ZnO/CHX), iodine-polyvinylpyrrolidone (ZnO/J-PVP), or a mixture of CHX and J-PVP and ZnO (ZnO/CHX/J-PVP) were tested for their ability to inhibit growth of pure cultures of bacterial species commonly involved in endodontic infections (Peptostreptococcus micros, Streptococcus intermedius, Enterococcus faecalis, and Porphyromonas gingivalis). To quantitate growth inhibition, an in vitro assay was established that controlled for important parameters of root canal infection. Approximately 10(7) bacteria per assay were suspended in diluted human serum and co-incubated with the gutta-percha points in an anaerobic atmosphere for up to 2 wk. Aliquots used for determination of colony counts were taken on days 0, 1, 2, 4, 7, and 14 of incubation. As judged by colony-forming unit reduction kinetics and final counts, calcium hydroxide had better growth inhibitory activity than ZnO/CHX, ZnO/J-PVP, and ZnO alone for all bacteria tested except Peptostreptococcus micros. The combination of CHX and J-PVP with ZnO did not render results different from those of ZnO/CHX or ZnO/J-PVP. The results of this study support the introduction of standardized assays for testing antibacterial properties of root canal medications under conditions that more closely resemble those encountered in endodontal infections. PMID:11199764

Podbielski, A; Boeckh, C; Haller, B

2000-07-01

408

Optimizing conditions for the growth of Lactobacillus casei YIT 9018 in tryptone-yeast extract-glucose medium by using response surface methodology.  

PubMed Central

This study was undertaken to find optimum conditions of tryptone, yeast extract, glucose, Tween 80, and incubation temperature for the growth of Lactobacillus casei YIT 9018 and to assess the effects of these factors by use of response surface methodology. A central composite design was used as an experimental design for allocation of treatment combinations. A second-order polynomial regression model, which was used at first for analysis of the experiment, had a significant lack of fit. Therefore, cubic and quartic terms were incorporated into the regression model through variable selection procedures. Effects involving incubation temperature, yeast extract, glucose, and tryptone were significant, whereas the only significant effect involving Tween 80 was the interaction effect between temperature and Tween 80. It turned out that growth of L. casei YIT 9018 was most strongly affected by the incubation temperature. Estimated optimum conditions of the factors for growth of L. casei YIT 9018 are as follows: tryptone, 3.04%; yeast extract, 0.892%; glucose, 1.58%; Tween 80, 0%; incubation temperature, 35 degrees C.

Oh, S; Rheem, S; Sim, J; Kim, S; Baek, Y

1995-01-01

409

A feedback-based implementation scheme for batch process optimization  

Microsoft Academic Search

The terminal-cost optimization of a control–affine nonlinear system leads to a discontinuous solution that can be characterized in a piecewise manner. To implement such an optimal trajectory despite disturbances and parametric uncertainty, a cascade optimization scheme is proposed in this paper, where optimal reference signals are tracked. Optimality is achieved by the appropriate definition of reference signals (input bounds, state

E. Visser; B. Srinivasan; S. Palanki; D. Bonvin

2000-01-01

410

Optimal conditions for genetic transformations of the cyanobacterium Anacystis nidulans R2  

Microsoft Academic Search

Under optimal conditions, the cyanobacterium Anacystis nidulans R2 was transformed to ampicillin resistance at frequencies of >10⁷ transformants per ..mu..g of plasmid (pCH1) donor DNA. No stringent period of competency was detected, and high frequencies of transformation were achieved with cultures at various growth stages. Transformation increased with time after addition of donor DNA up to 15 to 18 h.

S. S. Golden; L. A. Sherman

1984-01-01

411

MOVPE growth of AlGaN\\/GaN superlattices on ZnO substrates for green emitter applications  

Microsoft Academic Search

AlGaN\\/GaN superlattice structures have been deposited on (0001) ZnO substrates by metalorganic vapor phase epitaxy. The growth conditions were first optimized on GaN templates using N2 as carrier gas at relatively low temperature (<800°C), which is suitable for GaN growth on a ZnO substrate. Experimental results show that high interfacial quality can be achieved in the superlattice by using TMIn

Hongbo Yu; Shenjie Wang; Nola Li; William Fenwick; Andrew Melton; B. Klein; Ian Ferguson

2008-01-01

412

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

413

Achieving Tobacco Cessation: Current Status, Current Problems, Future Possibilities  

Microsoft Academic Search

Assisting smokers to achieve tobacco cessation has always been difficult. The development of pharmacological approaches to the attainment of abstinence from tobacco usage has been very helpful, although our understanding of optimal clinical use is still incomplete and imperfect. Bupropion and nicotine therapy (NT) will help reduce the severity of nicotine withdrawal symptoms, whether used separately or in combination. Effectiveness

Laszlo T. Vaszar; Priscilla S. A. Sarinas; Glen A. Lillington

2002-01-01

414

Achieving Professional Community in Schools: The Administrator Challenge  

ERIC Educational Resources Information Center

|Teachers, administrators and policy makers at all levels of public education remain challenged to devise more effective ways to optimize teacher performance and, thereby, student achievement. Numerous professional organizations and teacher training agencies have long been advocates of high levels of teacher interaction and have formally adopted…

Leonard, Lawrence J.; Leonard, Pauline E.

2005-01-01

415

Alkaline lipase from a novel strain Burkholderia multivorans: Statistical medium optimization and production in a bioreactor  

Microsoft Academic Search

An alkaline lipase from Burkholderia multivorans was produced within 15h of growth in a 14L bioreactor. An overall 12-fold enhanced production (58UmL?1 and 36Umg?1 protein) was achieved after medium optimization following the “one-variable-at-a-time” and the statistical approaches. The optimal composition of the lipase production medium was determined to be (% w\\/v or v\\/v): KH2PO4 0.1; K2HPO4 0.3; NH4Cl 0.5; MgSO4·7H2O

Namita Gupta; Vikram Sahai; Rani Gupta

2007-01-01

416

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

NASA Astrophysics Data System (ADS)

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 °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 °C and solution concentration of 0.03 M possess highest aspect ratio of ˜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 abstractThe ZnO nanorod arrays demonstrate well-alignment, high aspect ratio (L/D˜21) and excellent optical transmittance by low-temperature chemical bath deposition (CBD). Display Omitted

Lee, Yi-Mu; Yang, Hsi-Wen

2011-03-01

417

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

SciTech Connect

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

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

1995-06-01

418

Combined optimization model for sustainable energization strategy  

NASA Astrophysics Data System (ADS)

Access to energy is a foundation to establish a positive impact on multiple aspects of human development. Both developed and developing countries have a common concern of achieving a sustainable energy supply to fuel economic growth and improve the quality of life with minimal environmental impacts. The Least Developing Countries (LDCs), however, have different economic, social, and energy systems. Prevalence of power outage, lack of access to electricity, structural dissimilarity between rural and urban regions, and traditional fuel dominance for cooking and the resultant health and environmental hazards are some of the distinguishing characteristics of these nations. Most energy planning models have been designed for developed countries' socio-economic demographics and have missed the opportunity to address special features of the poor countries. An improved mixed-integer programming energy-source optimization model is developed to address limitations associated with using current energy optimization models for LDCs, tackle development of the sustainable energization strategies, and ensure diversification and risk management provisions in the selected energy mix. The Model predicted a shift from traditional fuels reliant and weather vulnerable energy source mix to a least cost and reliable modern clean energy sources portfolio, a climb on the energy ladder, and scored multifaceted economic, social, and environmental benefits. At the same time, it represented a transition strategy that evolves to increasingly cleaner energy technologies with growth as opposed to an expensive solution that leapfrogs immediately to the cleanest possible, overreaching technologies.

Abtew, Mohammed Seid

419

Achieving Permanency for LGBTQ Youth  

Microsoft Academic Search

The Adoption and Safe Families Act (ASFA) of 1997 requires states to assure the permanency, safety and well being for all children and youth in the foster care system. Although there has been considerable progress in achieving permanency for many children and youth, some youth in foster care - particularly lesbian, gay, bisexual, transgender, and questioning (LGBTQ) youth - have

Madelyn Freundlich

420

Scheduling and Achievement. Research Brief  

ERIC Educational Resources Information Center

To use a block schedule or a traditional schedule? Which structure will produce the best and highest achievement rates for students? The research is mixed on this due to numerous variables such as: (1) socioeconomic levels; (2) academic levels; (3) length of time a given schedule has been in operation; (4) strategies being used in the classrooms;…

Walker, Karen

2006-01-01

421

Institutional Climate and Minority Achievement.  

ERIC Educational Resources Information Center

|This paper discusses ways that institutions can change the higher education system and environment to accommodate more minority students. The first section, "Institutional Climate and Minority Achievement," presents an overview of the problems facing colleges and universities with respect to recruiting and retaining minority students. In the…

Richardson, Richard C.

422

Achieving a sustainable service advantage.  

PubMed

Many managers believe that superior service should play little or no role in competitive strategy; they maintain that service innovations are inherently copiable. However, the author states that this view is too narrow. For a company to achieve a lasting service advantage, it must base a new service on a capability gap that competitors cannot or will not copy. PMID:10123422

Coyne, K P

423

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…

Tomul, Ekber; Savasci, Havva Sebile

2012-01-01

424

Teacher Influences on Student Achievement  

Microsoft Academic Search

Research spanning two decades indicates that effective teaching demands the orchestration of a wide array of skills that must be adapted to specific contexts. Brophy reviews research that indicates that students achieve more when their teachers emphasize academic objectives in establishing expectations and allocating time, use effective management strategies to ensure that academic learning time is maximized, pace students through

Jere Brophy

1986-01-01

425

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

426

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

427

Achieving urinary continence in children  

Microsoft Academic Search

Achievement of urinary continence is an important developmental step that most children attain with the assistance of their parents and caregivers. Debate continues as to the best time to toilet train; in some Asian and African cultures children are trained as infants, while training at age 2–3 years is more typical in Western cultures. Infant voiding is not merely a

Hsi-Yang Wu

2010-01-01

428

Achieving Transaction Scaleup on Unix  

Microsoft Academic Search

Constructing scalable high-performance applications on commodity hardware running the Unix operating system is a problem that must be addressed in several application domains. We relate our experience in achieving transaction scaleup on Unix for a high-performance OLTP system intended for Service Control Points (SCPs) in a telephone switching network. SCPs are but one example from a class of applications whose

Marie-anne Neimat; Donovan A. Schneider

1994-01-01

429

Models for Evaluating Individual Achievement.  

ERIC Educational Resources Information Center

|Evaluation of nontraditional educational programs and individual achievement is discussed in terms of three components: process-environment, objectives, and evaluation. The combinations of these components in traditional and nontraditional orientations are each presented and examined as possible models for measurement of educational outcomes.…

Dressel, Paul L.

1980-01-01

430

Educational Achievement and Sex Discrimination.  

ERIC Educational Resources Information Center

|In the past years the National Assessment of Educational Progress (NAEP) has released results from a variety of learning areas. The purpose of this paper is to point out male-female differences in achievement across several learning areas. Hopefully, the results discussed here will be used as a basis for examining the possible existence of social…

Mullis, Ina V. S.

431

Hispanic Student Achievement. Research Brief  

ERIC Educational Resources Information Center

|What are the factors affecting the achievement of Hispanic high school youth? Hispanic Americans are the largest growing population in the United States. Currently, Hispanic students make up more than 20% of the U.S. school population and, in 23 of the 50 states, Hispanic students outnumber African American and Asian students. During the 1970s…

Hansen, Angela L.

2005-01-01

432

Washington State's Student Achievement Initiative  

ERIC Educational Resources Information Center

|This article describes Washington State's Student Achievement Initiative, an accountability system implemented in 2005-06 that measures students' gains in college readiness, college credits earned, and degree or certificate completion. The goal of the initiative is to increase educational attainment by focusing on the critical momentum points…

Pettitt, Maureen; Prince, David

2010-01-01

433

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

434

Literacy Achievement in Nongraded Classrooms  

ERIC Educational Resources Information Center

This longitudinal quantitative study compared literacy achievement of students from second through sixth grade based on two organizational systems: graded (traditional) and nongraded (multiage) classrooms. The California Standards Test (CST) scaled and proficiency scores for English-Language Arts (ELA) were used as the study's independent variable…

Kreide, Anita Therese

2011-01-01

435

Achieving Permanency for LGBTQ Youth  

ERIC Educational Resources Information Center

|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…

Jacobs, Jill; Freundlich, Madelyn

2006-01-01

436

Achieving world class maintenance status  

SciTech Connect

The article written by a management consultant, discusses the art of successful planning and operation of maintenance in mines considering factors such as benchmaking, key performance indices (KPIs) and frequency of procedures which can help achieve 'world class maintenance'. 1 fig.

Tomlingson, P.D. [Paul D. Tomingson Associates (United States)

2007-08-15

437

Primary Mental Abilities and Metropolitan Readiness Tests as Predictors of Achievement in the First Primary Year.  

ERIC Educational Resources Information Center

|The prediction of achievement provides teachers with necessary information to help children attain optimal achievement. If some skill prerequistites to learning which are not fully developed can be identified and strengthened, higher levels of achievement may result. The Metropolitan Readiness Tests (MRT) are routinely given to all University…

University City School District, MO.

438

Optimization Online  

NSDL National Science Digital Library

Optimization Online is one of the best sources for current research papers and reports on the topic of optimization. This repository receives numerous submissions each month, and papers can be browsed by data added or category. In addition to searching for articles on the site, visitors can also subscribe to the Optimization Online monthly digest and receive updates on all of the new titles and reports submitted during that month.

2008-05-19

439

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

440

Optimal Centroid Position Estimation  

SciTech Connect

The alignment of high energy laser beams for potential fusion experiments demand high precision and accuracy by the underlying positioning algorithms. This paper discusses the feasibility of employing online optimal position estimators in the form of model-based processors to achieve the desired results. Here we discuss the modeling, development, implementation and processing of model-based processors applied to both simulated and actual beam line data.

Candy, J V; McClay, W A; Awwal, A S; Ferguson, S W

2004-07-23

441

Metacognition, Achievement Goals, Study Strategies and Academic Achievement: Pathways to Achievement  

ERIC Educational Resources Information Center

The purpose of this research was to develop and test a model of effective self-regulated learning. Based on effort expenditure we discerned effective self-regulators and less effective self-regulators. The model comprised achievement goals (mastery, performance-approach and -avoidance goals), metacognition (metacognitive knowledge, regulation and…

Vrugt, Anneke; Oort, Frans J.

2008-01-01

442

Invented Spelling and Reading Achievement  

Microsoft Academic Search

The purpose of this study was to determine if first graders, invented spelling and Marie Clay’s Concepts of Print test, used together and separately, are significant predictors of future reading achievement. The study also compared the prediction ability of an invented spelling stage to the prediction ability of the Concepts of Print test.\\u000aThe subjects of this study comprised 39

Laurie Chaplen Lopez

1991-01-01

443

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

444

Otitis media and academic achievements  

Microsoft Academic Search

Objective: This is a study of whether there are any long-term differences in academic achievements between children with and without observed or treated middle ear disease in a population with a stable long-standing treatment policy. Methods: A birth cohort of 2156 children was previously studied through a questionnaire to the parents at 4 years of age, follow-up after audiometric screening

Ingrid Augustsson; Ingemar Engstand

2001-01-01

445

Beam cooling: Principles and achievements  

SciTech Connect

After a discussion of Liouville's theorem, and its implications for beam cooling, a brief description is given of each of the various methods of beam cooling: stochastic, electron, radiation, laser, ionization, etc. For each, we present the type of particle for which it is appropriate, its range of applicability, and the currently achieved degree of cooling. For each method we also discuss the present applications and, also, possible future developments and further applications.

Mohl, Dieter; Sessler, Andrew M.

2003-05-18

446

Development of a novel direct bioautography-thin-layer chromatography test: optimization of growth conditions for gram-positive bacteria, Bacillus subtilis.  

PubMed

A TLC-direct bioautography (DB) assay using Bacillus subtilis as test bacteria was developed. Various factors affecting the microorganism's viability on the TLC plates were studied and verified for the flumequine standards. The Dhenasar's method called "direct sample determination" was used for TLC; the antibiotic samples were spotted on the TLC plates and subjected to bioautography without developing with a mobile phase. The best preincubation and incubation times of bacterial broth were found to be 1 h at 37 degrees C and 6 h at 37 degrees C. The optimal viscosity of broth was obtained by the addition of agarose to obtain a 0.05% solution in the Mueller-Hinton broth. The best incubation time of seeded TLC plates was 17 h at 37 degrees C. The plates were visualized by spraying with 0.2% aqueous 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide solution and incubated again for 0.5 h at 37 degrees C. The method was validated by determination of linearity, interday and intraday precision, LOD, and LOQ. The calibration curves showed good linearity in the range 0.005-0.5 microg (0.5-50.0 microg/mL). The regression coefficients were 0.9970 and 0.9955 for intraday and interday plots, respectively. The LOD of flumequine equalled 0.5 microg/mL, i.e., 5 ng of the antibiotic in the spot. The sensitivity of the developed TLC-DB test was compared with that of the two most commonly used standard antimicrobial susceptibility assays: agar disc diffusion and agar cylinder diffusion. The obtained minimum inhibitory concentration values clearly indicate much higher sensitivity of the TLC-DB method compared to the standard antimicrobial susceptibility assays. PMID:23767364

Grzelak, Edyta M; Majer-Dziedzic, Barbara; Choma, Irena M; Pilorz, Karol M

447

Population growth and economic growth.  

PubMed

This discussion of the issues relating to the problem posed by population explosion in the developing countries and economic growth in the contemporary world covers the following: predictions of economic and social trends; the Malthusian theory of population; the classical or stationary theory of population; the medical triage model; ecological disaster; the Global 2000 study; the limits to growth; critiques of the Limits to Growth model; nonrenewable resources; food and agriculture; population explosion and stabilization; space and ocean colonization; and the limits perspective. The Limits to Growth model, a general equilibrium anti-growth model, is the gloomiest economic model ever constructed. None of the doomsday models, the Malthusian theory, the classical stationary state, the neo-Malthusian medical triage model, the Global 2000 study, are so far reaching in their consequences. The course of events that followed the publication of the "Limits to Growth" in 1972 in the form of 2 oil shocks, food shock, pollution shock, and price shock seemed to bear out formally the gloomy predictions of the thesis with a remarkable speed. The 12 years of economic experience and the knowledge of resource trends postulate that even if the economic pressures visualized by the model are at work they are neither far reaching nor so drastic. Appropriate action can solve them. There are several limitations to the Limits to Growth model. The central theme of the model, which is overshoot and collapse, is unlikely to be the course of events. The model is too aggregative to be realistic. It exaggerates the ecological disaster arising out of the exponential growth of population and industry. The gross underestimation of renewable resources is a basic flaw of the model. The most critical weakness of the model is its gross underestimation of the historical trend of technological progress and the technological possiblities within industry and agriculture. The model does correctly emphasize the exponential growth of population as the source of several complications for economic growth and human welfare. Stabilization of population by reducing fertility is conducive for improving the quality of population and also advances the longterm management of the population growth and work force utilization. The perspective of longterm economic management involves populatio n planning, control of environmental pollution, conservation of scarce resources, exploration of resources, realization of technological possibilities in agriculture and industry and in farm and factory, and achievement of economic growth and its equitable distribution. PMID:12314595

Narayana, D L

448

Ejector optimization  

Microsoft Academic Search

The ejector optimization process has been amended to include supersonic mixing. Several examples of ejector optimization have been calculated. Two of these examples have been checked experimentally. In one case for a pressure ratio of 3.1 and a mass flow ratio of 2.2 with air as operating media, experiment and analysis are in good agreement. For the other case with

S. H. Hasinger

1978-01-01

449

Optimizing TCP Forwarding  

Microsoft Academic Search

The continued growth of the web places ever increasing performance demands on web site front-end appliances. In many cases, these appliances have to forward network traffic to and from web servers at transport and application levels utilizing complete TCP\\/IP stack processing, which could easily make the front-end appliance a bottleneck for a web site. This paper describes four novel optimizations

Vsevolod V. Panteleenko; Vincent W. Freeh

450

Optimizing development projects in mature basins  

SciTech Connect

BP Exploration wishes to grow its gas business substantially and the Southern North Sea area expects to be a significant contributor to this growth. The Southern North Sea gas basin is characterised by a relatively large number of small prospects and discoveries lying within the catchment areas of existing pipeline systems serving larger fields currently in production. This growth will be achieved through expansion of production from existing large mature fields and new satellite developments, connected to existing pipeline systems. Significant modification to existing infrastructure will be required to bring the new production on stream. The low materiality of many of these new developments means that, based on current cost paradigms, they are sub-economic or do not offer returns commensurate with the risk. Also, implementation based on classical approaches tends to be resource-intensive in terms of key skills. Critical areas of concern in delivering growth objectives therefore relate to management of cost, implementation time and productivity of key human resources. The general approach adopted in pursuit of high performance includes a number of features: Innovative approaches to the service industries; simplification of equipment; streamlining of methodologies; application of novel technology; alignment of motivation of all contributors to overall objectives; and shifting the paradigm of risk. BP believes that this approach is a major breakthrough in extending and expanding the life of its assets in the Southern North Sea and is representative of the trend of optimization in the extended life of the Basin in general.

Swan, P.J. [BP Exploration, Aberdeen (United Kingdom)

1995-08-01

451

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

2013-09-25

452

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

2010-02-24

453

A Unified Approach to QoS-Guaranteed Scheduling for Channel-Adaptive Wireless Networks Terminals wirelessly-linked to an access point should be able to achieve near-optimal data rates, while maintaining required quality of service, by using simple scheduling algorithms  

Microsoft Academic Search

Scheduling amounts to allocating optimally channel, rate and power resources to multiple connections with diverse quality-of-service (QoS) requirements. It consti- tutes a throughput-critical task at the medium access control layer of today's wireless networks that has been tackled by seemingly unrelated information-theoretic and protocol design approaches. Capitalizing on convex optimization and stochastic approximation tools, the present paper develops a unified

Xin Wang; Georgios B. Giannakis; Antonio G. Marques

454

Achievement motivation and small business success in Transkei  

Microsoft Academic Search

The success of small firms is crucial for the creation and expansion of employment opportunities. Success in business often relies on entrepreneurial skills and attributes. This article examines the effect of one of these attributes, need achievement (n?Ach), on entrepreneurial success as measured by asset, sales and labour growth. N?Ach was found to be a significant predictor of success for

D. Mahadea

1994-01-01

455

Devolution, sustainability and GDP convergence: Is the Welsh agenda achievable?  

Microsoft Academic Search

Mainwaring L., Jones R. and Blackaby D. (2006) Devolution, sustainability and GDP convergence: is the Welsh agenda achievable?, Regional Studies40, 679–689. The Welsh Assembly Government has a constitutional duty to promote sustainable development. The devolution settlement does not, however, empower the Assembly to deviate from UK tax rates, while the Assembly Government has itself adopted ambitious gross domestic product growth

Lynn Mainwaring; Richard Jones; David Blackaby

2006-01-01

456

Model based optimization of some growth process parameters of a Nd:YVO4 cylindrical bar grown by edge-defined film-fed growth (EFG) method in the presence of the pressure  

NASA Astrophysics Data System (ADS)

The purpose of this paper is to find those values of the radius r0e of the outer edge of the die, pulling rate v, melt temperature T0 at the meniscus basis and pressure p in the furnace, which assure the growth of a Nd:YVO4 monocrystal cylindrical bar with prescribed radius rf and for which the surface non-uniformity of the bar, due to small uncontrollable oscillations of v and T0, is minimum. Numerical results are given for a Nd:YVO4 cylindrical bar of 2.5 (mm) radius, grown in a furnace in which the vertical temperature gradient is k = 33 (K/mm) for four type of uncontrollable oscillations: O1 = (?v = ±0.001 (mm/s) and ?T = ±1 (K)), O2 = (?v = ±0.01 (mm/s) and ?T = ±10 (K)), O3 = (?v = ±0.02 (mm/s) and ?T = ±20 (K)), O4 = (?v = ±0.001 (mm/s) and ?T = ±30 (K)), respectively. For a smooth surface, the parameters r0e, v and T0 has to be chosen as follows:r0e = 2.6 (mm), p = 0.002 (atm), v = 0.0011 (mm/s), T0 = 2102 (K) in the case O1;r0e = 2.6 (mm), p = 0.002 (atm), v = 0.0101 (mm/s), T0 = 2100 (K) in the case O2;r0e = 2.7 (mm), p = 0.002 (atm), v = 0.0201 (mm/s), T0 = 2111 (K) in the case O3;r0e = 2.7 (mm), p = 0.002 (atm), v = 0.0011 (mm/s), T0 = 2118 (K) in the case O4.

Braescu, L.; Balint, A. M.; Szabo, R.; Balint, St.

2006-05-01

457

Mathematical Optimization  

NSDL National Science Digital Library

Some of the most fundamental problems in engineering, science, and mathematics would take the most powerful computer in the world several lifetimes to find an optimal solution. However, near-optimal solutions to many of these problems have been discovered thanks to various methods of mathematical optimization. This Topic in Depth looks at some optimization techniques and the areas to which they have been applied.Argonne National Laboratory hosts an online guide (1) to some of the most well known optimization problems and algorithms. People who are new to the subject can find a wealth of introductory material in the Optimization Tree section, and several applications are illustrated with interactive demonstrations in the Case Studies section. Optimization has roots in operations research, and this tutorial (2) covers many topics within OR. A fun applet requires the user to place as many queens on a chess board as possible without any two being in direct line-of-sight, and an accompanying discussion shows how linear programming can be used to solve this problem; this is one of many resources contained within the tutorial. Two chemical engineering professors at Carnegie Mellon University are the authors of Retrospective on Optimization (3), a fairly comprehensive paper chronicling the history of optimization problems and the development of solution methods. The 51-page document is divided into two main parts; the first outlines some of the most significant advances in the field, and the second looks ahead toward key areas of research needed to evolve optimization further. Highway planning and development is the focus of this paper (4), which proposes using, among other things, genetic algorithms to optimize highway alignment. The authors state that this technique could be used to avoid delays and added costs due to changing plans later in the construction process. Another use of genetic algorithms in optimization is highlighted in this document from the German Aerospace Center (5). The document describes how a novel method for robot design, which involves formulating mathematical representations of robotic constraints and kinematics. These figures can then be used as parameters in a genetic algorithm that would optimize component placement while maintaining the desired functionality. A joint effort between architecture and mechanical engineering researchers at the University of Michigan (6) applied geometrical and topological optimization techniques to building floorplan layout. In the course of their research, they developed an optimization tool that is briefly described and can be downloaded from a Web site given in the paper. The Mathematical Programming Glossary (7) contains short discussions of hundreds of terms related to optimization theory. Each entry includes a clear definition and hyperlinks to other terms, and some of the entries are accompanied by a more in-depth supplement. One of the best sources for current research papers and reports is Optimization Online (8). This repository receives numerous submissions each month, and papers can be browsed by data added or category.

Leske, Cavin.

458

Erbium concentration control and optimization in erbium yttrium chloride silicate single crystal nanowires as a high gain material  

NASA Astrophysics Data System (ADS)

Increasing erbium concentration while minimizing the reduction of photoluminescence is an important task for achieving erbium-based high-gain materials for integrated photonics applications. Here, we demonstrate a strategy of controlled variation of Erbium density in the growth of erbium yttrium chloride silicate (EYCS) ((ErxY1-x)3(SiO4)2Cl)) single crystal nanowires by systematically varying x between 0 and 1. We show that, as a trade-off between high Er density and suppressed upconversion, Er composition x = 0.3 provides the best compromise with the strongest photoluminescence. This optimized Er-composition corresponds to an Er density of 5×1021 cm-3, five times larger than the optimized Er density demonstrated previously for other thin film materials. We estimate that this optimized EYCS is promising in achieving optical gain exceeding 100 dB/cm.

Yin, Leijun; Shelhammer, David; Zhao, Gejian; Liu, Zhicheng; Ning, C. Z.

2013-09-01

459

Modernizing China's Growth Paradigm  

Microsoft Academic Search

China has achieved tremendous economic progress in the last three decades, but there is much work to be done to make the economy resilient to large shocks, ensure the sustainability of its growth, and translate this growth into corresponding improvements in the economic welfare of its citizens. We discuss the complex challenges that Chinese policymakers face in striking the right

Eswar S. Prasad; Raghuram G. Rajan

2006-01-01

460

Achieving outcomes through organizational redesign.  

PubMed

The current health care environment demands delivery of high quality health services within increasingly restricted cost parameters. To meet these demands health care organizations are seeking performance improvement at every level within the organization. Delivering care is the core business of health care organizations. It is a complex process composed of multiple, interfacing processes and subprocesses. Successful redesign does not seek to make incremental improvement, but to create a new organizational framework in which processes enable achievement of quality, service, and cost outcomes. This article examines drivers for redesign, presents a process for redesigning health care organizations, describes successful management of organizational change, and presents a case study of a successful redesign initiative. PMID:9254643

Strong, A; Yarde, H

1997-09-01