Optimizing the Galileo space communication link

NASA Technical Reports Server (NTRS)

Statman, J. I.

1994-01-01

The Galileo mission was originally designed to investigate Jupiter and its moons utilizing a high-rate, X-band (8415 MHz) communication downlink with a maximum rate of 134.4 kb/sec. However, following the failure of the high-gain antenna (HGA) to fully deploy, a completely new communication link design was established that is based on Galileo's S-band (2295 MHz), low-gain antenna (LGA). The new link relies on data compression, local and intercontinental arraying of antennas, a (14,1/4) convolutional code, a (255,M) variable-redundancy Reed-Solomon code, decoding feedback, and techniques to reprocess recorded data to greatly reduce data losses during signal acquisition. The combination of these techniques will enable return of significant science data from the mission.

The SYSGEN user package

NASA Technical Reports Server (NTRS)

Carlson, C. R.

1981-01-01

The user documentation of the SYSGEN model and its links with other simulations is described. The SYSGEN is a production costing and reliability model of electric utility systems. Hydroelectric, storage, and time dependent generating units are modeled in addition to conventional generating plants. Input variables, modeling options, output variables, and reports formats are explained. SYSGEN also can be run interactively by using a program called FEPS (Front End Program for SYSGEN). A format for SYSGEN input variables which is designed for use with FEPS is presented.

Multidisciplinary design optimization of aircraft wing structures with aeroelastic and aeroservoelastic constraints

NASA Astrophysics Data System (ADS)

Jung, Sang-Young

Design procedures for aircraft wing structures with control surfaces are presented using multidisciplinary design optimization. Several disciplines such as stress analysis, structural vibration, aerodynamics, and controls are considered simultaneously and combined for design optimization. Vibration data and aerodynamic data including those in the transonic regime are calculated by existing codes. Flutter analyses are performed using those data. A flutter suppression method is studied using control laws in the closed-loop flutter equation. For the design optimization, optimization techniques such as approximation, design variable linking, temporary constraint deletion, and optimality criteria are used. Sensitivity derivatives of stresses and displacements for static loads, natural frequency, flutter characteristics, and control characteristics with respect to design variables are calculated for an approximate optimization. The objective function is the structural weight. The design variables are the section properties of the structural elements and the control gain factors. Existing multidisciplinary optimization codes (ASTROS* and MSC/NASTRAN) are used to perform single and multiple constraint optimizations of fully built up finite element wing structures. Three benchmark wing models are developed and/or modified for this purpose. The models are tested extensively.

On implementation of the extended interior penalty function. [optimum structural design

NASA Technical Reports Server (NTRS)

Cassis, J. H.; Schmit, L. A., Jr.

1976-01-01

The extended interior penalty function formulation is implemented. A rational method for determining the transition between the interior and extended parts is set forth. The formulation includes a straightforward method for avoiding design points with some negative components, which are physically meaningless in structural analysis. The technique, when extended to problems involving parametric constraints, can facilitate closed form integration of the penalty terms over the most important parts of the parameter interval. The method lends itself well to the use of approximation concepts, such as design variable linking, constraint deletion and Taylor series expansions of response quantities in terms of design variables. Examples demonstrating the algorithm, in the context of planar orthogonal frames subjected to ground motion, are included.

Numerical analysis of right-half plane zeros for a single-link manipulator. M.S. Thesis

NASA Technical Reports Server (NTRS)

Girvin, Douglas Lynn

1992-01-01

The purpose of this research is to further develop an understanding of how nonminimum phase zero location is affected by structural link design. As the demand for light-weight robots that can operate in a large workspace increases, the structural flexibility of the links become more of an issue in controls problems. When the objective is to accurately position the tip while the robot is actuated at the base, the system is nonminimum phase. One important characteristic of nonminimum phase systems is system zeros in the right half of the Laplace plane. The ability to pick the location of these nonminimum phase zeros would give the designer a new freedom similar to pole placement. The research targets a single-link manipulator operating in the horizontal plane and modeled as a Euler-Bernoulli beam with pinned-free end conditions. Using transfer matrix theory, one can consider link designs that have variable cross-sections along the length of the beam. A FORTRAN program was developed to determine the location of poles and zeros given the system model. The program was used to confirm previous research on nonminimum phase systems, and develop a relationship for designing linearly tapered links. The method allows the designer to choose the location of the first pole and zero and then defines the appropriate taper to match the desired locations. With the pole and zero location fixes, the designer can independently change the link's moment of inertia about its axis of rotation by adjusting the height of the beam. These results can be applied to inverse dynamic algorithms currently under development at Georgia Tech.

Mixed Transportation Network Design under a Sustainable Development Perspective

PubMed Central

Qin, Jin; Ni, Ling-lin; Shi, Feng

2013-01-01

A mixed transportation network design problem considering sustainable development was studied in this paper. Based on the discretization of continuous link-grade decision variables, a bilevel programming model was proposed to describe the problem, in which sustainability factors, including vehicle exhaust emissions, land-use scale, link load, and financial budget, are considered. The objective of the model is to minimize the total amount of resources exploited under the premise of meeting all the construction goals. A heuristic algorithm, which combined the simulated annealing and path-based gradient projection algorithm, was developed to solve the model. The numerical example shows that the transportation network optimized with the method above not only significantly alleviates the congestion on the link, but also reduces vehicle exhaust emissions within the network by up to 41.56%. PMID:23476142

Mixed transportation network design under a sustainable development perspective.

PubMed

Qin, Jin; Ni, Ling-lin; Shi, Feng

2013-01-01

A mixed transportation network design problem considering sustainable development was studied in this paper. Based on the discretization of continuous link-grade decision variables, a bilevel programming model was proposed to describe the problem, in which sustainability factors, including vehicle exhaust emissions, land-use scale, link load, and financial budget, are considered. The objective of the model is to minimize the total amount of resources exploited under the premise of meeting all the construction goals. A heuristic algorithm, which combined the simulated annealing and path-based gradient projection algorithm, was developed to solve the model. The numerical example shows that the transportation network optimized with the method above not only significantly alleviates the congestion on the link, but also reduces vehicle exhaust emissions within the network by up to 41.56%.

Case-Crossover Analysis of Air Pollution Health Effects: A Systematic Review of Methodology and Application

PubMed Central

Carracedo-Martínez, Eduardo; Taracido, Margarita; Tobias, Aurelio; Saez, Marc; Figueiras, Adolfo

2010-01-01

Background Case-crossover is one of the most used designs for analyzing the health-related effects of air pollution. Nevertheless, no one has reviewed its application and methodology in this context. Objective We conducted a systematic review of case-crossover (CCO) designs used to study the relationship between air pollution and morbidity and mortality, from the standpoint of methodology and application. Data sources and extraction A search was made of the MEDLINE and EMBASE databases. Reports were classified as methodologic or applied. From the latter, the following information was extracted: author, study location, year, type of population (general or patients), dependent variable(s), independent variable(s), type of CCO design, and whether effect modification was analyzed for variables at the individual level. Data synthesis The review covered 105 reports that fulfilled the inclusion criteria. Of these, 24 addressed methodological aspects, and the remainder involved the design’s application. In the methodological reports, the designs that yielded the best results in simulation were symmetric bidirectional CCO and time-stratified CCO. Furthermore, we observed an increase across time in the use of certain CCO designs, mainly symmetric bidirectional and time-stratified CCO. The dependent variables most frequently analyzed were those relating to hospital morbidity; the pollutants most often studied were those linked to particulate matter. Among the CCO-application reports, 13.6% studied effect modification for variables at the individual level. Conclusions The use of CCO designs has undergone considerable growth; the most widely used designs were those that yielded better results in simulation studies: symmetric bidirectional and time-stratified CCO. However, the advantages of CCO as a method of analysis of variables at the individual level are put to little use. PMID:20356818

Designing low-carbon power systems for Great Britain in 2050 that are robust to the spatiotemporal and inter-annual variability of weather

NASA Astrophysics Data System (ADS)

Zeyringer, Marianne; Price, James; Fais, Birgit; Li, Pei-Hao; Sharp, Ed

2018-05-01

The design of cost-effective power systems with high shares of variable renewable energy (VRE) technologies requires a modelling approach that simultaneously represents the whole energy system combined with the spatiotemporal and inter-annual variability of VRE. Here, we soft-link a long-term energy system model, which explores new energy system configurations from years to decades, with a high spatial and temporal resolution power system model that captures VRE variability from hours to years. Applying this methodology to Great Britain for 2050, we find that VRE-focused power system design is highly sensitive to the inter-annual variability of weather and that planning based on a single year can lead to operational inadequacy and failure to meet long-term decarbonization objectives. However, some insights do emerge that are relatively stable to weather-year. Reinforcement of the transmission system consistently leads to a decrease in system costs while electricity storage and flexible generation, needed to integrate VRE into the system, are generally deployed close to demand centres.

Quality-by-Design (QbD): An integrated process analytical technology (PAT) approach for a dynamic pharmaceutical co-precipitation process characterization and process design space development.

PubMed

Wu, Huiquan; White, Maury; Khan, Mansoor A

2011-02-28

The aim of this work was to develop an integrated process analytical technology (PAT) approach for a dynamic pharmaceutical co-precipitation process characterization and design space development. A dynamic co-precipitation process by gradually introducing water to the ternary system of naproxen-Eudragit L100-alcohol was monitored at real-time in situ via Lasentec FBRM and PVM. 3D map of count-time-chord length revealed three distinguishable process stages: incubation, transition, and steady-state. The effects of high risk process variables (slurry temperature, stirring rate, and water addition rate) on both derived co-precipitation process rates and final chord-length-distribution were evaluated systematically using a 3(3) full factorial design. Critical process variables were identified via ANOVA for both transition and steady state. General linear models (GLM) were then used for parameter estimation for each critical variable. Clear trends about effects of each critical variable during transition and steady state were found by GLM and were interpreted using fundamental process principles and Nyvlt's transfer model. Neural network models were able to link process variables with response variables at transition and steady state with R(2) of 0.88-0.98. PVM images evidenced nucleation and crystal growth. Contour plots illustrated design space via critical process variables' ranges. It demonstrated the utility of integrated PAT approach for QbD development. Published by Elsevier B.V.

Closed loop supply chain network design with fuzzy tactical decisions

NASA Astrophysics Data System (ADS)

Sherafati, Mahtab; Bashiri, Mahdi

2016-09-01

One of the most strategic and the most significant decisions in supply chain management is reconfiguration of the structure and design of the supply chain network. In this paper, a closed loop supply chain network design model is presented to select the best tactical and strategic decision levels simultaneously considering the appropriate transportation mode in activated links. The strategic decisions are made for a long term; thus, it is more satisfactory and more appropriate when the decision variables are considered uncertain and fuzzy, because it is more flexible and near to the real world. This paper is the first research which considers fuzzy decision variables in the supply chain network design model. Moreover, in this study a new fuzzy optimization approach is proposed to solve a supply chain network design problem with fuzzy tactical decision variables. Finally, the proposed approach and model are verified using several numerical examples. The comparison of the results with other existing approaches confirms efficiency of the proposed approach. Moreover the results confirms that by considering the vagueness of tactical decisions some properties of the supply chain network will be improved.

Optimal output fast feedback in two-time scale control of flexible arms

NASA Technical Reports Server (NTRS)

Siciliano, B.; Calise, A. J.; Jonnalagadda, V. R. P.

1986-01-01

Control of lightweight flexible arms moving along predefined paths can be successfully synthesized on the basis of a two-time scale approach. A model following control can be designed for the reduced order slow subsystem. The fast subsystem is a linear system in which the slow variables act as parameters. The flexible fast variables which model the deflections of the arm along the trajectory can be sensed through strain gage measurements. For full state feedback design the derivatives of the deflections need to be estimated. The main contribution of this work is the design of an output feedback controller which includes a fixed order dynamic compensator, based on a recent convergent numerical algorithm for calculating LQ optimal gains. The design procedure is tested by means of simulation results for the one link flexible arm prototype in the laboratory.

Rain rate intensity model for communication link design across the Indian region

NASA Astrophysics Data System (ADS)

Kilaru, Aravind; Kotamraju, Sarat K.; Avlonitis, Nicholas; Sri Kavya, K. Ch.

2016-07-01

A study on rain statistical parameters such as one minute rain intensity, possible number of minute occurrences with respective percentage of time in a year has been evaluated for the purpose of communication link design at Ka, Q, V bands as well as at Free-Space Optical communication links (FSO). To understand possible outage period of a communication links due to rainfall and to investigate rainfall pattern, Automatic Weather Station (AWS) rainfall data is analysed due its ample presence across India. The climates of the examined AWS regions vary from desert to cold climate, heavy rainfall to variable rainfall regions, cyclone effective regions, mountain and coastal regions. In this way a complete and unbiased picture of the rainfall statistics for Indian region is evaluated. The analysed AWS data gives insight into yearly accumulated rainfall, maximum hourly accumulated rainfall, mean hourly accumulated rainfall, number of rainy days and number of rainy hours from 668 AWS locations. Using probability density function the one minute rainfall measurements at KL University is integrated with AWS measurements for estimating number of rain occurrences in terms of one minute rain intensity for annual rainfall accumulated between 100 mm and 5000 mm to give an insight into possible one minute accumulation pattern in an hour for comprehensive analysis of rainfall influence on a communication link for design engineers. So that low availability communications links at higher frequencies can be transformed into a reliable and economically feasible communication links for implementing High Throughput Services (HTS).

Multinational Corporations, Democracy and Child Mortality: A Quantitative, Cross-National Analysis of Developing Countries

ERIC Educational Resources Information Center

Shandra, John M.; Nobles, Jenna E.; London, Bruce; Williamson, John B.

2005-01-01

This study presents quantitative, sociological models designed to account for cross-national variation in child mortality. We consider variables linked to five different theoretical perspectives that include the economic modernization, social modernization, political modernization, ecological-evolutionary, and dependency perspectives. The study is…

ED QUEST: A Process for Linking Environmental Changes with Strategic Management. [Revised].

ERIC Educational Resources Information Center

Morrison, James L.; Mecca, Thomas V.

Educational Quick Environmental Scanning Technique (ED QUEST) is a process designed to identify emerging issues and events that indicate potential threats and opportunities to educational organizations, to analyze the probable impact of these variables on the organization, and to facilitate the development of appropriate organizational strategies.…

The controlled growth method - A tool for structural optimization

NASA Technical Reports Server (NTRS)

Hajela, P.; Sobieszczanski-Sobieski, J.

1981-01-01

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

Assessing factorial invariance of two-way rating designs using three-way methods

PubMed Central

Kroonenberg, Pieter M.

2015-01-01

Assessing the factorial invariance of two-way rating designs such as ratings of concepts on several scales by different groups can be carried out with three-way models such as the Parafac and Tucker models. By their definitions these models are double-metric factorially invariant. The differences between these models lie in their handling of the links between the concept and scale spaces. These links may consist of unrestricted linking (Tucker2 model), invariant component covariances but variable variances per group and per component (Parafac model), zero covariances and variances different per group but not per component (Replicated Tucker3 model) and strict invariance (Component analysis on the average matrix). This hierarchy of invariant models, and the procedures by which to evaluate the models against each other, is illustrated in some detail with an international data set from attachment theory. PMID:25620936

Development of a non-piston MR suspension rod for variable mass systems

NASA Astrophysics Data System (ADS)

Deng, Huaxia; Han, Guanghui; Zhang, Jin; Wang, Mingxian; Ma, Mengchao; Zhong, Xiang; Yu, Liandong

2018-06-01

The semi-active suspension systems for variable mass systems require long work stroke and variable damping, while the currently piston structure limits the work stroke for the magnetorheological (MR) dampers. The main work of this paper is to design a semi-active non-piston MR (NPMR) suspension rod for the reduction of the vibration of an automatic impeller washing machine, which is a typical variable mass system. The designed suspension rod locates in the suspension system that links the internal tub to the washing machine cabinet. The NPMR suspension rod includes a MR part and a air part. The MR part can provide low initial damping force and the unlimited work stroke compared with the piston MR damper. The hysteretic response tests and vibration performance evaluation with different loadings are conducted to verify the dynamic performance for the designed rod. The measured damping force of the MR part varies from 5 to 20 N. Studies of dehydration mode experiments of the washing machine indicate that its vibration acceleration with the NPMR suspension rods can reduce to half of the original passive ones in certain conditions.

Adaptable structural synthesis using advanced analysis and optimization coupled by a computer operating system

NASA Technical Reports Server (NTRS)

Sobieszczanski-Sobieski, J.; Bhat, R. B.

1979-01-01

A finite element program is linked with a general purpose optimization program in a 'programing system' which includes user supplied codes that contain problem dependent formulations of the design variables, objective function and constraints. The result is a system adaptable to a wide spectrum of structural optimization problems. In a sample of numerical examples, the design variables are the cross-sectional dimensions and the parameters of overall shape geometry, constraints are applied to stresses, displacements, buckling and vibration characteristics, and structural mass is the objective function. Thin-walled, built-up structures and frameworks are included in the sample. Details of the system organization and characteristics of the component programs are given.

Daily variability in working memory is coupled with negative affect: the role of attention and motivation.

PubMed

Brose, Annette; Schmiedek, Florian; Lövdén, Martin; Lindenberger, Ulman

2012-06-01

Across days, individuals experience varying levels of negative affect, control of attention, and motivation. We investigated whether this intraindividual variability was coupled with daily fluctuations in working memory (WM) performance. In 100 days, 101 younger individuals worked on a spatial N-back task and rated negative affect, control of attention, and motivation. Results showed that individuals differed in how reliably WM performance fluctuated across days, and that subjective experiences were primarily linked to performance accuracy. WM performance was lower on days with higher levels of negative affect, reduced control of attention, and reduced task-related motivation. Thus, variables that were found to predict WM in between-subjects designs showed important relationships to WM at the within-person level. In addition, there was shared predictive variance among predictors of WM. Days with increased negative affect and reduced performance were also days with reduced control of attention and reduced motivation to work on tasks. These findings are in line with proposed mechanisms linking negative affect and cognitive performance.

Do cooperative learning and family involvement improve variables linked to academic performance?

PubMed

Santos Rego, Miguel A; Ferraces Otero, María J; Godas Otero, Agustín; Lorenzo Moledo, María M

2018-05-01

One of the most serious problems in the Spanish education system is the high percentage of school failure in Compulsory Secondary Education. The aim of this study is to analyze the influence of a socio-educational program based on cooperative learning and family involvement on a series of variables related to academic performance, paying particular attention to the differences between retained and non-retained students. A two-group quasi-experimental design incorporating pre-testing and post-testing was used. The study involved 146 students in the experimental group and 123 in the control group, 8 teachers, and 89 parents or other family members. The program was observed to have a positive effect on self-image, study habits, satisfaction with the subject, maternal support and control, and opinions about the school. In addition, the results for non-retained students are better. Cooperative work and family involvement in education affect the variables which research links to improving school performance.

[Effects of prevention education on Human Papillomavirus linked to cervix cancer for unmarried female university students].

PubMed

Kim, Hae Won

2009-08-01

This study was done to identify the effects of a Human Papillomavirus (HPV) linked to cervix cancer prevention education program for unmarried university female students. A new model in the cervix cancer prevention is provided. The research design was a nonequivalent control group pretest-posttest design. Participants were 63 female students in one of two university in an experimental group (29 students) and control group (34 students). After 4 weeks education, the differences between the two groups in the measurement variables were compared. Twelve weeks later, a follow-up test was done for experimental group only. After the education, experimental group showed significantly higher scores in all variables, the intention for Pap test (Z=-3.73, p<.001), intention for HPV vaccination (Z=-3.14, p=.002), general cancer prevention behavior (Z=-2.20, p=.028), attitudes to Pap (Z=-3.23, p=.001), benefits of cancer prevention behavior (Z=-3.97, p<.001), and HPV linked to cervix cancer knowledge (Z=-5.40, p<.001). In the follow-up study, the experimental group showed intermediate effects in intention for Pap test, intention of HPV vaccination and HPV linked to cervix cancer knowledge as well as short term effects in general cancer prevention behavior, attitudes to Pap and benefits of cancer prevention behavior. The program developed for this study on prevention education of HPV linked to cervix cancer was effective for unmarried university students in the short term and intermediate duration. Other educational approaches should be developed and short term effects and longitudinal changes of the education should be assessed. This education program should also be replicated for other female groups including unmarried working women or female adolescents.

A previously unreported, dominantly inherited syndrome of shortness of stature, ear malformations, and hip dislocation: the coxoauricular syndrome--autosomal or X-linked male-lethal.

PubMed

Duca, D; Pană, I; Ciovirnache, M; Simionesu, L; Ispas, I; Maxililian, C

1981-01-01

We reported an apparently previously undescribed syndrome, designated the coxoauricular syndrome, in a mother and her 3 daughters, all of whom shared in variable manner shortness of stature, minor vertebral and pelvic changes, dislocated hip(s), and microtia with corresponding hearing loss. The oldest daughter had coincidental Ullrich-Turner syndrome with 46, Xdel(X)(q 13) chromosome constitution. Inheritance of the trait in this family is dominant, either autosomal or X-linked, with hemizygote lethality.

Two-Time Scale Virtual Sensor Design for Vibration Observation of a Translational Flexible-Link Manipulator Based on Singular Perturbation and Differential Games

PubMed Central

Ju, Jinyong; Li, Wei; Wang, Yuqiao; Fan, Mengbao; Yang, Xuefeng

2016-01-01

Effective feedback control requires all state variable information of the system. However, in the translational flexible-link manipulator (TFM) system, it is unrealistic to measure the vibration signals and their time derivative of any points of the TFM by infinite sensors. With the rigid-flexible coupling between the global motion of the rigid base and the elastic vibration of the flexible-link manipulator considered, a two-time scale virtual sensor, which includes the speed observer and the vibration observer, is designed to achieve the estimation for the vibration signals and their time derivative of the TFM, as well as the speed observer and the vibration observer are separately designed for the slow and fast subsystems, which are decomposed from the dynamic model of the TFM by the singular perturbation. Additionally, based on the linear-quadratic differential games, the observer gains of the two-time scale virtual sensor are optimized, which aims to minimize the estimation error while keeping the observer stable. Finally, the numerical calculation and experiment verify the efficiency of the designed two-time scale virtual sensor. PMID:27801840

75 FR 78996 - Proposed Data Collections Submitted for Public Comment and Recommendations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-17

... Prevention Through Environmental Design: Linking Observed School Environments With Student and School-Wide... schools. Survey data from 75 students (25 each from 6th, 7th, and 8th grades) per school site will be... collection. The student survey will assess variables such as school climate, and actual and perceived levels...

An Algorithm for the Mixed Transportation Network Design Problem

PubMed Central

Liu, Xinyu; Chen, Qun

2016-01-01

This paper proposes an optimization algorithm, the dimension-down iterative algorithm (DDIA), for solving a mixed transportation network design problem (MNDP), which is generally expressed as a mathematical programming with equilibrium constraint (MPEC). The upper level of the MNDP aims to optimize the network performance via both the expansion of the existing links and the addition of new candidate links, whereas the lower level is a traditional Wardrop user equilibrium (UE) problem. The idea of the proposed solution algorithm (DDIA) is to reduce the dimensions of the problem. A group of variables (discrete/continuous) is fixed to optimize another group of variables (continuous/discrete) alternately; then, the problem is transformed into solving a series of CNDPs (continuous network design problems) and DNDPs (discrete network design problems) repeatedly until the problem converges to the optimal solution. The advantage of the proposed algorithm is that its solution process is very simple and easy to apply. Numerical examples show that for the MNDP without budget constraint, the optimal solution can be found within a few iterations with DDIA. For the MNDP with budget constraint, however, the result depends on the selection of initial values, which leads to different optimal solutions (i.e., different local optimal solutions). Some thoughts are given on how to derive meaningful initial values, such as by considering the budgets of new and reconstruction projects separately. PMID:27626803

Structural design optimization with survivability dependent constraints application: Primary wing box of a multi-role fighter

NASA Technical Reports Server (NTRS)

Dolvin, Douglas J.

1992-01-01

The superior survivability of a multirole fighter is dependent upon balanced integration of technologies for reduced vulnerability and susceptability. The objective is to develop a methodology for structural design optimization with survivability dependent constraints. The design criteria for optimization will be survivability in a tactical laser environment. The following analyses are studied to establish a dependent design relationship between structural weight and survivability: (1) develop a physically linked global design model of survivability variables; and (2) apply conventional constraints to quantify survivability dependent design. It was not possible to develop an exact approach which would include all aspects of survivability dependent design, therefore guidelines are offered for solving similar problems.

Design of an adaptive CubeSat transmitter for achieving optimum signal-to-noise ratio (SNR)

NASA Astrophysics Data System (ADS)

Jaswar, F. D.; Rahman, T. A.; Hindia, M. N.; Ahmad, Y. A.

2017-12-01

CubeSat technology has opened the opportunity to conduct space-related researches at a relatively low cost. Typical approach to maintain an affordable cubeSat mission is to use a simple communication system, which is based on UHF link with fixed-transmit power and data rate. However, CubeSat in the Low Earth Orbit (LEO) does not have relative motion with the earth rotation, resulting in variable propagation path length that affects the transmission signal. A transmitter with adaptive capability to select multiple sets of data rate and radio frequency (RF) transmit power is proposed to improve and optimise the link. This paper presents the adaptive UHF transmitter design as a solution to overcome the variability of the propagation path. The transmitter output power is adjustable from 0.5W to 2W according to the mode of operations and satellite power limitations. The transmitter is designed to have four selectable modes to achieve the optimum signal-to-noise ratio (SNR) and efficient power consumption based on the link budget analysis and satellite requirement. Three prototypes are developed and tested for space-environment conditions such as the radiation test. The Total Ionizing Dose measurements are conducted in the radiation test done at Malaysia Nuclear Agency Laboratory. The results from this test have proven that the adaptive transmitter can perform its operation with estimated more than seven months in orbit. This radiation test using gamma source with 1.5krad exposure is the first one conducted for a satellite program in Malaysia.

Further developments in the controlled growth approach for optimal structural synthesis

NASA Technical Reports Server (NTRS)

Hajela, P.

1982-01-01

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

The Bilingual Advantage for Immigrant Students in French Immersion in Canada: Linking Advantages to Contextual Variables

ERIC Educational Resources Information Center

Mady, Callie

2017-01-01

This study compares the English and French proficiencies of three groups of early French immersion participants at the Grade 6 level: Canadian-born English-speaking, Canadian-born multilingual, and immigrant multilingual students. In addition to English and French multi-skills tests, the participants completed a questionnaire designed to gather…

Port-O-Sim Object Simulation Application

NASA Technical Reports Server (NTRS)

Lanzi, Raymond J.

2009-01-01

Port-O-Sim is a software application that supports engineering modeling and simulation of launch-range systems and subsystems, as well as the vehicles that operate on them. It is flexible, distributed, object-oriented, and realtime. A scripting language is used to configure an array of simulation objects and link them together. The script is contained in a text file, but executed and controlled using a graphical user interface. A set of modules is defined, each with input variables, output variables, and settings. These engineering models can be either linked to each other or run as standalone. The settings can be modified during execution. Since 2001, this application has been used for pre-mission failure mode training for many Range Safety Scenarios. It contains range asset link analysis, develops look-angle data, supports sky-screen site selection, drives GPS (Global Positioning System) and IMU (Inertial Measurement Unit) simulators, and can support conceptual design efforts for multiple flight programs with its capacity for rapid six-degrees-of-freedom model development. Due to the assembly of various object types into one application, the application is applicable across a wide variety of launch range problem domains.

Linking Data for Mothers and Babies in De-Identified Electronic Health Data

PubMed Central

Gilbert, Ruth; Cromwell, David; van der Meulen, Jan

2016-01-01

Objective Linkage of longitudinal administrative data for mothers and babies supports research and service evaluation in several populations around the world. We established a linked mother-baby cohort using pseudonymised, population-level data for England. Design and Setting Retrospective linkage study using electronic hospital records of mothers and babies admitted to NHS hospitals in England, captured in Hospital Episode Statistics between April 2001 and March 2013. Results Of 672,955 baby records in 2012/13, 280,470 (42%) linked deterministically to a maternal record using hospital, GP practice, maternal age, birthweight, gestation, birth order and sex. A further 380,164 (56%) records linked using probabilistic methods incorporating additional variables that could differ between mother/baby records (admission dates, ethnicity, 3/4-character postcode district) or that include missing values (delivery variables). The false-match rate was estimated at 0.15% using synthetic data. Data quality improved over time: for 2001/02, 91% of baby records were linked (holding the estimated false-match rate at 0.15%). The linked cohort was representative of national distributions of gender, gestation, birth weight and maternal age, and captured approximately 97% of births in England. Conclusion Probabilistic linkage of maternal and baby healthcare characteristics offers an efficient way to enrich maternity data, improve data quality, and create longitudinal cohorts for research and service evaluation. This approach could be extended to linkage of other datasets that have non-disclosive characteristics in common. PMID:27764135

Modeling functional Magnetic Resonance Imaging (fMRI) experimental variables in the Ontology of Experimental Variables and Values (OoEVV)

PubMed Central

Burns, Gully A.P.C.; Turner, Jessica A.

2015-01-01

Neuroimaging data is raw material for cognitive neuroscience experiments, leading to scientific knowledge about human neurological and psychological disease, language, perception, attention and ultimately, cognition. The structure of the variables used in the experimental design defines the structure of the data gathered in the experiments; this in turn structures the interpretative assertions that may be presented as experimental conclusions. Representing these assertions and the experimental data which support them in a computable way means that they could be used in logical reasoning environments, i.e. for automated meta-analyses, or linking hypotheses and results across different levels of neuroscientific experiments. Therefore, a crucial first step in being able to represent neuroimaging results in a clear, computable way is to develop representations for the scientific variables involved in neuroimaging experiments. These representations should be expressive, computable, valid, extensible, and easy-to-use. They should also leverage existing semantic standards to interoperate easily with other systems. We present an ontology design pattern called the Ontology of Experimental Variables and Values (OoEVV). This is designed to provide a lightweight framework to capture mathematical properties of data, with appropriate ‘hooks’ to permit linkage to other ontology-driven projects (such as the Ontology of Biomedical Investigations, OBI). We instantiate the OoEVV system with a small number of functional Magnetic Resonance Imaging datasets, to demonstrate the system’s ability to describe the variables of a neuroimaging experiment. OoEVV is designed to be compatible with the XCEDE neuroimaging data standard for data collection terminology, and with the Cognitive Paradigm Ontology (CogPO) for specific reasoning elements of neuroimaging experimental designs. PMID:23684873

The impact of visual layout factors on performance in Web pages: a cross-language study.

PubMed

Parush, Avi; Shwarts, Yonit; Shtub, Avy; Chandra, M Jeya

2005-01-01

Visual layout has a strong impact on performance and is a critical factor in the design of graphical user interfaces (GUIs) and Web pages. Many design guidelines employed in Web page design were inherited from human performance literature and GUI design studies and practices. However, few studies have investigated the more specific patterns of performance with Web pages that may reflect some differences between Web page and GUI design. We investigated interactions among four visual layout factors in Web page design (quantity of links, alignment, grouping indications, and density) in two experiments: one with pages in Hebrew, entailing right-to-left reading, and the other with English pages, entailing left-to-right reading. Some performance patterns (measured by search times and eye movements) were similar between languages. Performance was particularly poor in pages with many links and variable densities, but it improved with the presence of uniform density. Alignment was not shown to be a performance-enhancing factor. The findings are discussed in terms of the similarities and differences in the impact of layout factors between GUIs and Web pages. Actual or potential applications of this research include specific guidelines for Web page design.

Report: Optimization study of the preparation factors for argan oil microcapsule based on hybrid-level orthogonal array design via SPSS modeling.

PubMed

Zhao, Xi; Wu, Xiaoli; Zhou, Hui; Jiang, Tao; Chen, Chun; Liu, Mingshi; Jin, Yuanbao; Yang, Dongsheng

2014-11-01

To optimize the preparation factors for argan oil microcapsule using complex coacervation of chitosan cross-linked with gelatin based on hybrid-level orthogonal array design via SPSS modeling. Eight relatively significant factors were firstly investigated and selected as calculative factors for the orthogonal array design from the total of ten factors effecting the preparation of argan oil microcapsule by utilizing the single factor variable method. The modeling of hybrid-level orthogonal array design was built in these eight factors with the relevant levels (9, 9, 9, 9, 7, 6, 2 and 2 respectively). The preparation factors for argan oil microcapsule were investigated and optimized according to the results of hybrid-level orthogonal array design. The priorities order and relevant optimum levels of preparation factors standard to base on the percentage of microcapsule with the diameter of 30~40 μm via SPSS. Experimental data showed that the optimum factors were controlling the chitosan/gelatin ratio, the systemic concentration and the core/shell ratio at 1:2, 1.5% and 1:7 respectively, presetting complex coacervation pH at 6.4, setting cross-linking time and complex coacervation at 75 min and 30 min, using the glucose-delta lactone as the type of cross-linking agent, and selecting chitosan with the molecular weight of 2000～3000.

Perception-Production Link in L2 Japanese Vowel Duration: Training with Technology

ERIC Educational Resources Information Center

Okuno, Tomoko; Hardison, Debra M.

2016-01-01

This study examined factors affecting perception training of vowel duration in L2 Japanese with transfer to production. In a pre-test, training, post-test design, 48 L1 English speakers were assigned to one of three groups: auditory-visual (AV) training using waveform displays, auditory-only (A-only), or no training. Within-group variables were…

Correlations among Five Demographic Variables and the Performance of Selected Jamaican 11th-Graders on Some Numerical Problems on Energy

ERIC Educational Resources Information Center

Emepue, Nicholas; Soyibo, Kola

2009-01-01

This study was designed to assess whether the level of performance of selected Jamaican 11th-grade physics students on some numerical problems on the energy concept was satisfactory and if there were significant differences in their performance linked to their gender, socioeconomic background (SEB), school location, English language and…

The Work Values of Teacher Training Students in a Spanish University. Symbiosis between Schwartz and Meaning of Work (MOW) Study Group

ERIC Educational Resources Information Center

Cortes Pascual, M. P. Alejandra

2009-01-01

Work values are linked with other relevant variables in career development, such as professional interests or vocational personality, are formed in a specific work context and influence the orientation intervention designed, for example, as an element of the professional portfolio or the development of transversal participatory and personal…

Coded throughput performance simulations for the time-varying satellite channel. M.S. Thesis

NASA Technical Reports Server (NTRS)

Han, LI

1995-01-01

The design of a reliable satellite communication link involving the data transfer from a small, low-orbit satellite to a ground station, but through a geostationary satellite, was examined. In such a scenario, the received signal power to noise density ratio increases as the transmitting low-orbit satellite comes into view, and then decreases as it then departs, resulting in a short-duration, time-varying communication link. The optimal values of the small satellite antenna beamwidth, signaling rate, modulation scheme and the theoretical link throughput (in bits per day) have been determined. The goal of this thesis is to choose a practical coding scheme which maximizes the daily link throughput while satisfying a prescribed probability of error requirement. We examine the throughput of both fixed rate and variable rate concatenated forward error correction (FEC) coding schemes for the additive white Gaussian noise (AWGN) channel, and then examine the effect of radio frequency interference (RFI) on the best coding scheme among them. Interleaving is used to mitigate degradation due to RFI. It was found that the variable rate concatenated coding scheme could achieve 74 percent of the theoretical throughput, equivalent to 1.11 Gbits/day based on the cutoff rate R(sub 0). For comparison, 87 percent is achievable for AWGN-only case.

Manipulators with flexible links: A simple model and experiments

NASA Technical Reports Server (NTRS)

Shimoyama, Isao; Oppenheim, Irving J.

1989-01-01

A simple dynamic model proposed for flexible links is briefly reviewed and experimental control results are presented for different flexible systems. A simple dynamic model is useful for rapid prototyping of manipulators and their control systems, for possible application to manipulator design decisions, and for real time computation as might be applied in model based or feedforward control. Such a model is proposed, with the further advantage that clear physical arguments and explanations can be associated with its simplifying features and with its resulting analytical properties. The model is mathematically equivalent to Rayleigh's method. Taking the example of planar bending, the approach originates in its choice of two amplitude variables, typically chosen as the link end rotations referenced to the chord (or the tangent) motion of the link. This particular choice is key in establishing the advantageous features of the model, and it was used to support the series of experiments reported.

Field test of classical symmetric encryption with continuous variables quantum key distribution.

PubMed

Jouguet, Paul; Kunz-Jacques, Sébastien; Debuisschert, Thierry; Fossier, Simon; Diamanti, Eleni; Alléaume, Romain; Tualle-Brouri, Rosa; Grangier, Philippe; Leverrier, Anthony; Pache, Philippe; Painchault, Philippe

2012-06-18

We report on the design and performance of a point-to-point classical symmetric encryption link with fast key renewal provided by a Continuous Variable Quantum Key Distribution (CVQKD) system. Our system was operational and able to encrypt point-to-point communications during more than six months, from the end of July 2010 until the beginning of February 2011. This field test was the first demonstration of the reliability of a CVQKD system over a long period of time in a server room environment. This strengthens the potential of CVQKD for information technology security infrastructure deployments.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitrani, J

Bayesian networks (BN) are an excellent tool for modeling uncertainties in systems with several interdependent variables. A BN is a directed acyclic graph, and consists of a structure, or the set of directional links between variables that depend on other variables, and conditional probabilities (CP) for each variable. In this project, we apply BN's to understand uncertainties in NIF ignition experiments. One can represent various physical properties of National Ignition Facility (NIF) capsule implosions as variables in a BN. A dataset containing simulations of NIF capsule implosions was provided. The dataset was generated from a radiation hydrodynamics code, and itmore » contained 120 simulations of 16 variables. Relevant knowledge about the physics of NIF capsule implosions and greedy search algorithms were used to search for hypothetical structures for a BN. Our preliminary results found 6 links between variables in the dataset. However, we thought there should have been more links between the dataset variables based on the physics of NIF capsule implosions. Important reasons for the paucity of links are the relatively small size of the dataset, and the sampling of the values for dataset variables. Another factor that might have caused the paucity of links is the fact that in the dataset, 20% of the simulations represented successful fusion, and 80% didn't, (simulations of unsuccessful fusion are useful for measuring certain diagnostics) which skewed the distributions of several variables, and possibly reduced the number of links. Nevertheless, by illustrating the interdependencies and conditional probabilities of several parameters and diagnostics, an accurate and complete BN built from an appropriate simulation set would provide uncertainty quantification for NIF capsule implosions.« less

Reducing the Language Content in ToM Tests: A Developmental Scale

ERIC Educational Resources Information Center

Burnel, Morgane; Perrone-Bertolotti, Marcela; Reboul, Anne; Baciu, Monica; Durrleman, Stephanie

2018-01-01

The goal of the current study was to statistically evaluate the reliable scalability of a set of tasks designed to assess Theory of Mind (ToM) without language as a confounding variable. This tool might be useful to study ToM in populations where language is impaired or to study links between language and ToM. Low verbal versions of the ToM tasks…

Multi-rate DPSK optical transceivers for free-space applications

NASA Astrophysics Data System (ADS)

Caplan, D. O.; Carney, J. J.; Fitzgerald, J. J.; Gaschits, I.; Kaminsky, R.; Lund, G.; Hamilton, S. A.; Magliocco, R. J.; Murphy, R. J.; Rao, H. G.; Spellmeyer, N. W.; Wang, J. P.

2014-03-01

We describe a flexible high-sensitivity laser communication transceiver design that can significantly benefit performance and cost of NASA's satellite-based Laser Communications Relay Demonstration. Optical communications using differential phase shift keying, widely deployed for use in long-haul fiber-optic networks, is well known for its superior sensitivity and link performance over on-off keying, while maintaining a relatively straightforward design. However, unlike fiber-optic links, free-space applications often require operation over a wide dynamic range of power due to variations in link distance and channel conditions, which can include rapid kHz-class fading when operating through the turbulent atmosphere. Here we discuss the implementation of a robust, near-quantum-limited multi-rate DPSK transceiver, co-located transmitter and receiver subsystems that can operate efficiently over the highly-variable free-space channel. Key performance features will be presented on the master oscillator power amplifier (MOPA) based TX, including a wavelength-stabilized master laser, high-extinction-ratio burst-mode modulator, and 0.5 W single polarization power amplifier, as well as low-noise optically preamplified DSPK receiver and built-in test capabilities.

Linking environmental variability to population and community dynamics: Chapter 7

USGS Publications Warehouse

Pantel, Jelena H.; Pendleton, Daniel E.; Walters, Annika W.; Rogers, Lauren A.

2014-01-01

Linking population and community responses to environmental variability lies at the heart of ecology, yet methodological approaches vary and existence of broad patterns spanning taxonomic groups remains unclear. We review the characteristics of environmental and biological variability. Classic approaches to link environmental variability to population and community variability are discussed as are the importance of biotic factors such as life history and community interactions. In addition to classic approaches, newer techniques such as information theory and artificial neural networks are reviewed. The establishment and expansion of observing networks will provide new long-term ecological time-series data, and with it, opportunities to incorporate environmental variability into research. This review can help guide future research in the field of ecological and environmental variability.

A systematic approach to parameter selection for CAD-virtual reality data translation using response surface methodology and MOGA-II.

PubMed

Abidi, Mustufa Haider; Al-Ahmari, Abdulrahman; Ahmad, Ali

2018-01-01

Advanced graphics capabilities have enabled the use of virtual reality as an efficient design technique. The integration of virtual reality in the design phase still faces impediment because of issues linked to the integration of CAD and virtual reality software. A set of empirical tests using the selected conversion parameters was found to yield properly represented virtual reality models. The reduced model yields an R-sq (pred) value of 72.71% and an R-sq (adjusted) value of 86.64%, indicating that 86.64% of the response variability can be explained by the model. The R-sq (pred) is 67.45%, which is not very high, indicating that the model should be further reduced by eliminating insignificant terms. The reduced model yields an R-sq (pred) value of 73.32% and an R-sq (adjusted) value of 79.49%, indicating that 79.49% of the response variability can be explained by the model. Using the optimization software MODE Frontier (Optimization, MOGA-II, 2014), four types of response surfaces for the three considered response variables were tested for the data of DOE. The parameter values obtained using the proposed experimental design methodology result in better graphics quality, and other necessary design attributes.

A pilot data collecting exercise on stress and nursing students.

PubMed

Por, Jitna

This article discusses the lessons learned from a small pilot study exploring the link between the working environment and occupational stress among groups of nursing students. A comparative descriptive design was adopted to examine, describe and compare the two variables (sources and frequency) in three groups of nursing students. The sample comprised 90 students from one large inner-city school of nursing in London. The Expanded Nursing Stress Scale questionnaires were used to collect the data. The main findings suggest that the adult, child and mental health branch students were similar with respect to overall frequency of occupational stress. Areas of commonality and variability in the sources of stress perceived by the three groups of students were identified. A pilot study is a crucial element of a good study design. Areas of concern, lessons learned and suggested refinements were identified.

Climate Informed Economic Instruments to Enhance Urban Water Supply Resilience to Hydroclimatological Variability and Change

NASA Astrophysics Data System (ADS)

Brown, C.; Carriquiry, M.; Souza Filho, F. A.

2006-12-01

Hydroclimatological variability presents acute challenges to urban water supply providers. The impact is often most severe in developing nations where hydrologic and climate variability can be very high, water demand is unmet and increasing, and the financial resources to mitigate the social effects of that variability are limited. Furthermore, existing urban water systems face a reduced solution space, constrained by competing and conflicting interests, such as irrigation demand, recreation and hydropower production, and new (relative to system design) demands to satisfy environmental flow requirements. These constraints magnify the impacts of hydroclimatic variability and increase the vulnerability of urban areas to climate change. The high economic and social costs of structural responses to hydrologic variability, such as groundwater utilization and the construction or expansion of dams, create a need for innovative alternatives. Advances in hydrologic and climate forecasting, and the increasing sophistication and acceptance of incentive-based mechanisms for achieving economically efficient water allocation offer potential for improving the resilience of existing water systems to the challenge of variable supply. This presentation will explore the performance of a system of climate informed economic instruments designed to facilitate the reduction of hydroclimatologic variability-induced impacts on water-sensitive stakeholders. The system is comprised of bulk water option contracts between urban water suppliers and agricultural users and insurance indexed on reservoir inflows designed to cover the financial needs of the water supplier in situations where the option is likely to be exercised. Contract and insurance parameters are linked to forecasts and the evolution of seasonal precipitation and streamflow and designed for financial and political viability. A simulation of system performance is presented based on ongoing work in Metro Manila, Philippines. The system is further evaluated as an alternative strategy to infrastructure expansion for climate change adaptation in the water resources sector.

Embedding the perceptions of people with dementia into quantitative research design.

PubMed

O'Rourke, Hannah M; Duggleby, Wendy; Fraser, Kimberly D

2015-05-01

Patient perspectives about quality of life are often found in the results of qualitative research and could be applied to steer the direction of future research. The purpose of this paper was to describe how findings from a body of qualitative research on patient perspectives about quality of life were linked to a clinical administrative dataset and then used to design a subsequent quantitative study. Themes from two systematic reviews of qualitative evidence (i.e., metasyntheses) identified what affects quality of life according to people with dementia. Selected themes and their sub-concepts were then mapped to an administrative dataset (the Resident Assessment Instrument 2.0) to determine the study focus, formulate nine hypotheses, and select a patient-reported outcome. A literature review followed to confirm existence of a knowledge gap, identify adjustment variables, and support design decisions. A quantitative study to test the association between conflict and sadness for people with dementia in long-term care was derived from metasynthesis themes. Challenges included (1) mapping broad themes to the administrative dataset; (2) decisions associated with inclusion of variables not identified by people with dementia from the qualitative research; and (3) selecting a patient-reported outcome, when the dataset lacked a valid subjective quality-of-life measure. Themes derived from a body of qualitative research capturing a target populations' perspective can be linked to administrative data and used to design a quantitative study. Using this approach, the quantitative findings will be meaningful with respect to the quality of life of the target population.

Study of design and control of remote manipulators. Part 2: Vibration considerations in manipulator design

NASA Technical Reports Server (NTRS)

Book, W. J.

1973-01-01

An investigation is reported involving a mathematical procedure using 4 x 4 transformation matrices for analyzing the vibrations of flexible manipulators. Previous studies with the procedure are summarized and the method is extended to include flexible joints as well as links, and to account for the effects of various power transmission schemes. A systematic study of the allocation of structural material and the placement of components such as motors and gearboxes was undertaken using the analytical tools developed. As one step in this direction the variables which relate the vibration parameters of the arm to the task and environment of the arm were isolated and nondimensionalized. The 4 x 4 transformation matrices were also used to develop analytical expressions for the terms of the complete 6 x 6 compliance matrix for the case of two flexible links joined by a rotating joint, flexible about its axis of rotation.

Structural optimization for joined-wing synthesis

NASA Technical Reports Server (NTRS)

Gallman, John W.; Kroo, Ilan M.

1992-01-01

The differences between fully stressed and minimum-weight joined-wing structures are identified, and these differences are quantified in terms of weight, stress, and direct operating cost. A numerical optimization method and a fully stressed design method are used to design joined-wing structures. Both methods determine the sizes of 204 structural members, satisfying 1020 stress constraints and five buckling constraints. Monotonic splines are shown to be a very effective way of linking spanwise distributions of material to a few design variables. Both linear and nonlinear analyses are employed to formulate the buckling constraints. With a constraint on buckling, the fully stressed design is shown to be very similar to the minimum-weight structure. It is suggested that a fully stressed design method based on nonlinear analysis is adequate for an aircraft optimization study.

Scheduler Design Criteria: Requirements and Considerations

NASA Technical Reports Server (NTRS)

Lee, Hanbong

2016-01-01

This presentation covers fundamental requirements and considerations for developing schedulers in airport operations. We first introduce performance and functional requirements for airport surface schedulers. Among various optimization problems in airport operations, we focus on airport surface scheduling problem, including runway and taxiway operations. We then describe a basic methodology for airport surface scheduling such as node-link network model and scheduling algorithms previously developed. Next, we explain how to design a mathematical formulation in more details, which consists of objectives, decision variables, and constraints. Lastly, we review other considerations, including optimization tools, computational performance, and performance metrics for evaluation.

Host-dependent variables: The missing link to personalized medicine.

PubMed

Demlova, Regina; Zdrazilova-Dubska, Lenka; Sterba, Jaroslav; Stanta, Giorgio; Valik, Dalibor

2018-04-26

Individualized medicine has the potential to tailor anticancer therapy with the best response and highest safety margin to provide better patient care. However, modern targeted therapies are still being tested through clinical trials comparing preselected patient cohorts and assessed upon behaviour of group averages. Clinically manifesting malignant disease requires identification of host- and tumour-dependent variables such as biological characteristics of the tumour and its microenvironment including immune response features, and overall capacity of the host to receive, tolerate and efficiently utilize treatment. Contemporary medical oncology including clinical trial design need to refocus from assessing group averages to individuality taking into consideration time dependent host-associated characteristics and reinventing outliers to be appreciated as naturally occurring variables collectively determining the ultimate outcome of malignant disease. Copyright © 2018. Published by Elsevier Ltd.

A Single Molecular Diels-Alder Crosslinker for Achieving Recyclable Cross-Linked Polymers.

PubMed

Chen, Shengli; Wang, Fenfen; Peng, Yongjin; Chen, Tiehong; Wu, Qiang; Sun, Pingchuan

2015-09-01

A triol-functional crosslinker combining the thermoreversible properties of Diels-Alder (DA) adducts in one molecule is designed, synthesized, and used as an ideal substitute of a traditional crosslinker to prepare thermal recyclable cross-linked polyurethanes with excellent mechanical properties and recyclability in a very simple and efficient way. The recycle property of these materials achieved by the DA/retro-DA reaction at a suitable temperature is verified by differential scanning calorimetry and in situ variable temperature solid-state NMR experiments during the cyclic heating and cooling processes. The thermal recyclability and remending ability of the bulk polyurethanes is demonstrated by three polymer processing methods, including hot-press molding, injection molding, and solution casting. It is notable that all the recycled cross-linked polymers display nearly invariable elongation/stress at break compared to the as-synthesized samples. Further end-group functionalization of this single molecular DA crosslinker provides the potential in preparing a wide range of recyclable cross-linked polymers. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dynamically-allocated multi-queue buffers for VLSI communication switches

NASA Technical Reports Server (NTRS)

Tamir, Yuval; Frazier, Gregory L.

1992-01-01

Several buffer structures are discussed and compared in terms of implementation complexity, interswitch handshaking requirements, and their ability to deal with variations in traffic patterns and message lengths. A new design of buffers is presented that provide non-FIFO message handling and efficient storage allocation for variable size packets using linked lists managed by a simple on-chip controller. The new buffer design is evaluated by comparing it to several alternative designs in the context of a multistage interconnection network. The present modeling and simulations show that the new buffer outperforms alternative buffers and can thus be used to improve the performance of a wide variety of systems currently using less efficient buffers.

Genetic algorithm optimization of transcutaneous energy transmission systems for implantable ventricular assist devices.

PubMed

Byron, Kelly; Bluvshtein, Vlad; Lucke, Lori

2013-01-01

Transcutaneous energy transmission systems (TETS) wirelessly transmit power through the skin. TETS is particularly desirable for ventricular assist devices (VAD), which currently require cables through the skin to power the implanted pump. Optimizing the inductive link of the TET system is a multi-parameter problem. Most current techniques to optimize the design simplify the problem by combining parameters leading to sub-optimal solutions. In this paper we present an optimization method using a genetic algorithm to handle a larger set of parameters, which leads to a more optimal design. Using this approach, we were able to increase efficiency while also reducing power variability in a prototype, compared to a traditional manual design method.

Applying causal mediation analysis to personality disorder research.

PubMed

Walters, Glenn D

2018-01-01

This article is designed to address fundamental issues in the application of causal mediation analysis to research on personality disorders. Causal mediation analysis is used to identify mechanisms of effect by testing variables as putative links between the independent and dependent variables. As such, it would appear to have relevance to personality disorder research. It is argued that proper implementation of causal mediation analysis requires that investigators take several factors into account. These factors are discussed under 5 headings: variable selection, model specification, significance evaluation, effect size estimation, and sensitivity testing. First, care must be taken when selecting the independent, dependent, mediator, and control variables for a mediation analysis. Some variables make better mediators than others and all variables should be based on reasonably reliable indicators. Second, the mediation model needs to be properly specified. This requires that the data for the analysis be prospectively or historically ordered and possess proper causal direction. Third, it is imperative that the significance of the identified pathways be established, preferably with a nonparametric bootstrap resampling approach. Fourth, effect size estimates should be computed or competing pathways compared. Finally, investigators employing the mediation method are advised to perform a sensitivity analysis. Additional topics covered in this article include parallel and serial multiple mediation designs, moderation, and the relationship between mediation and moderation. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Logical Experimental Design and Execution in the Biomedical Sciences.

PubMed

Holder, Daniel J; Marino, Michael J

2017-03-17

Lack of reproducibility has been highlighted as a significant problem in biomedical research. The present unit is devoted to describing ways to help ensure that research findings can be replicated by others, with a focus on the design and execution of laboratory experiments. Essential components for this include clearly defining the question being asked, using available information or information from pilot studies to aid in the design the experiment, and choosing manipulations under a logical framework based on Mill's "methods of knowing" to build confidence in putative causal links. Final experimental design requires systematic attention to detail, including the choice of controls, sample selection, blinding to avoid bias, and the use of power analysis to determine the sample size. Execution of the experiment is done with care to ensure that the independent variables are controlled and the measurements of the dependent variables are accurate. While there are always differences among laboratories with respect to technical expertise, equipment, and suppliers, execution of the steps itemized in this unit will ensure well-designed and well-executed experiments to answer any question in biomedical research. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

Combining Genotype, Phenotype, and Environment to Infer Potential Candidate Genes.

PubMed

Talbot, Benoit; Chen, Ting-Wen; Zimmerman, Shawna; Joost, Stéphane; Eckert, Andrew J; Crow, Taylor M; Semizer-Cuming, Devrim; Seshadri, Chitra; Manel, Stéphanie

2017-03-01

Population genomic analysis can be an important tool in understanding local adaptation. Identification of potential adaptive loci in such analyses is usually based on the survey of a large genomic dataset in combination with environmental variables. Phenotypic data are less commonly incorporated into such studies, although combining a genome scan analysis with a phenotypic trait analysis can greatly improve the insights obtained from each analysis individually. Here, we aimed to identify loci potentially involved in adaptation to climate in 283 Loblolly pine (Pinus taeda) samples from throughout the species' range in the southeastern United States. We analyzed associations between phenotypic, molecular, and environmental variables from datasets of 3082 single nucleotide polymorphism (SNP) loci and 3 categories of phenotypic traits (gene expression, metabolites, and whole-plant traits). We found only 6 SNP loci that displayed potential signals of local adaptation. Five of the 6 identified SNPs are linked to gene expression traits for lignin development, and 1 is linked with whole-plant traits. We subsequently compared the 6 candidate genes with environmental variables and found a high correlation in only 3 of them (R2 > 0.2). Our study highlights the need for a combination of genotypes, phenotypes, and environmental variables, and for an appropriate sampling scheme and study design, to improve confidence in the identification of potential candidate genes. © The American Genetic Association 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Representing Functions in n Dimensions to Arbitrary Accuracy

NASA Technical Reports Server (NTRS)

Scotti, Stephen J.

2007-01-01

A method of approximating a scalar function of n independent variables (where n is a positive integer) to arbitrary accuracy has been developed. This method is expected to be attractive for use in engineering computations in which it is necessary to link global models with local ones or in which it is necessary to interpolate noiseless tabular data that have been computed from analytic functions or numerical models in n-dimensional spaces of design parameters.

The Effect of Propulsion Style on Wrist Movement Variability During the Push Phase After a Bout of Fatiguing Propulsion.

PubMed

Zukowski, Lisa A; Christou, Evangelos A; Shechtman, Orit; Hass, Christopher J; Tillman, Mark D

2017-03-01

Wheelchair propulsion has been linked to overuse injuries regardless of propulsion style. Many aspects of the arcing (ARC) and semicircular (SEMI) propulsion styles have been compared, but differences in intracycle movement variability, which have been linked to overuse injuries, have not been examined. To explore how ARC and SEMI affect changes in intracycle wrist movement variability after a fatiguing bout of propulsion. Repeated measures crossover design. Wheelchair rollers and wheelchair fatigue course in a research laboratory. Twenty healthy, nondisabled adult men without previous wheelchair experience. Participants learned ARC and SEMI and used each to perform a wheelchair fatigue protocol. Thirty seconds of propulsion on rollers were recorded by motion-capture cameras before and after a fatigue protocol for each propulsion style on 2 testing days. Angular wrist orientations (flexion/extension and radial/ulnar deviation) and linear wrist trajectories (mediolateral direction) were computed, and intracycle movement variability was calculated as standard deviations of the detrended and filtered values during the push phase beginning and end. Paired samples t tests were used to compare ARC and SEMI based on the percent changes from pre- to postfatigue protocol. Both propulsion styles resulted in increased intracycle wrist movement variability postfatigue, but observed increases did not significantly differ between ARC and SEMI. This study evinces that intersubject variability exceeded average changes in intracycle wrist movement variability for both propulsion styles. Neither propulsion style resulting in a greater change in intracycle movement variability may suggest that no single propulsion style is ideal for everyone. The large intersubject variability may indicate that the propulsion style resulting in the smallest increase in intracycle movement variability after a fatiguing bout of propulsion may differ for each person and may help explain why wheelchair users self-select to use different propulsion styles. Copyright © 2017 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Remote sensing using MIMO systems

DOEpatents

Bikhazi, Nicolas; Young, William F; Nguyen, Hung D

2015-04-28

A technique for sensing a moving object within a physical environment using a MIMO communication link includes generating a channel matrix based upon channel state information of the MIMO communication link. The physical environment operates as a communication medium through which communication signals of the MIMO communication link propagate between a transmitter and a receiver. A spatial information variable is generated for the MIMO communication link based on the channel matrix. The spatial information variable includes spatial information about the moving object within the physical environment. A signature for the moving object is generated based on values of the spatial information variable accumulated over time. The moving object is identified based upon the signature.

Water availability as a driver of spatial and temporal variability in vegetation in the La Mancha plain (Spain): Implications for the land-surface energy, water and carbon budget

NASA Astrophysics Data System (ADS)

Los, Sietse

2017-04-01

Vegetation is water limited in large areas of Spain and therefore a close link exists between vegetation greenness observed from satellite and moisture availability. Here we exploit this link to infer spatial and temporal variability in moisture from MODIS NDVI data and thermal data. Discrepancies in the precipitation - vegetation relationship indicate areas with an alternative supply of water (i.e. not rainfall), this can be natural where moisture is supplied by upwelling groundwater, or can be artificial where crops are irrigated. As a result spatial and temporal variability in vegetation in the La Mancha Plain appears closely linked to topography, geology, rainfall and land use. Crop land shows large variability in year-to-year vegetation greenness; for some areas this variability is linked to variability in rainfall but in other cases this variability is linked to irrigation. The differences in irrigation treatment within one plant functional type, in this case crops, will lead to errors in land surface models when ignored. The magnitude of these effects on the energy, carbon and water balance are assessed at the scale of 250 m to 200 km. Estimating the water balance correctly is of particular important since in some areas in Spain more water is used for irrigation than is supplemented by rainfall.

Types of prayer and depressive symptoms among cancer patients: the mediating role of rumination and social support.

PubMed

Pérez, John E; Rex Smith, Amy; Norris, Rebecca L; Canenguez, Katia M; Tracey, Elizabeth F; Decristofaro, Susan B

2011-12-01

We examined the association between different types of prayer and depressive symptoms--with rumination and social support as potential mediators--in a sample of predominantly White, Christian, and female ambulatory cancer patients. In a cross-sectional design, 179 adult cancer outpatients completed measures of prayer, rumination, social support, depressive symptoms, and demographic variables. Type and stage of cancer were collected from electronic medical charts. Depressive symptoms were negatively correlated with adoration prayer (r = -.15), reception prayer (r = -.17), thanksgiving prayer (r = -.29), and prayer for the well-being of others (r = -.26). In the path analysis, rumination fully mediated the link between thanksgiving prayer and depressive symptoms (β for indirect effect = -.05), whereas social support partially mediated the link between prayer for others and depressive symptoms (β for indirect effect = -.05). These findings suggest that unique mechanisms may link different prayer types to lower depressive symptoms among cancer patients.

Heart rate variability and the anxious client: cardiac autonomic and behavioral associations with therapeutic alliance.

PubMed

Stratford, Trisha; Meara, Alan; Psychotherapy, M Gestalt; Lal, Sara

2014-08-01

This exploratory study was designed to investigate the link between a client's heart rate variability (HRV) and the forming of a therapeutic alliance (TA) during psychotherapy. Change in HRV is associated with many psychological and physiological situations, including cardiac mortality. Cardiac effects were evaluated during therapy in 30 symptomatically anxious clients using HRV during six weekly 1-hour therapy sessions (S1-S6). Therapeutic index (TI), a measure of TA, was evaluated using skin conductance resonance between client and therapist. The Working Alliance Inventory provides a subjective measure of TA. State and trait anxiety and mood states were also assessed. Most HRV parameters were highest during S4. The sympathovagal balance was highest in S1 but stabilized after S2. In S4, TI was linked to high HRV parameters. Overall higher anxiety levels seem to be associated to lower HRV parameters. Conversely, in S4, high HRV parameters were linked to higher mood scores. This study found that a subjective measure of TA contradicted the physiological outcome. Results suggest that physiological data collected during therapy are a more accurate barometer of TA forming. These research findings suggest a need for further research identifying physiological markers in clients with a variety of mental health disorders over long-term therapy.

Bayesian regression discontinuity designs: incorporating clinical knowledge in the causal analysis of primary care data.

PubMed

Geneletti, Sara; O'Keeffe, Aidan G; Sharples, Linda D; Richardson, Sylvia; Baio, Gianluca

2015-07-10

The regression discontinuity (RD) design is a quasi-experimental design that estimates the causal effects of a treatment by exploiting naturally occurring treatment rules. It can be applied in any context where a particular treatment or intervention is administered according to a pre-specified rule linked to a continuous variable. Such thresholds are common in primary care drug prescription where the RD design can be used to estimate the causal effect of medication in the general population. Such results can then be contrasted to those obtained from randomised controlled trials (RCTs) and inform prescription policy and guidelines based on a more realistic and less expensive context. In this paper, we focus on statins, a class of cholesterol-lowering drugs, however, the methodology can be applied to many other drugs provided these are prescribed in accordance to pre-determined guidelines. Current guidelines in the UK state that statins should be prescribed to patients with 10-year cardiovascular disease risk scores in excess of 20%. If we consider patients whose risk scores are close to the 20%  risk score threshold, we find that there is an element of random variation in both the risk score itself and its measurement. We can therefore consider the threshold as a randomising device that assigns statin prescription to individuals just above the threshold and withholds it from those just below. Thus, we are effectively replicating the conditions of an RCT in the area around the threshold, removing or at least mitigating confounding. We frame the RD design in the language of conditional independence, which clarifies the assumptions necessary to apply an RD design to data, and which makes the links with instrumental variables clear. We also have context-specific knowledge about the expected sizes of the effects of statin prescription and are thus able to incorporate this into Bayesian models by formulating informative priors on our causal parameters. © 2015 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Control of flexible robots with prismatic joints and hydraulic drives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Love, L.J.; Kress, R.L.; Jansen, J.F.

1997-03-01

The design and control of long-reach, flexible manipulators has been an active research topic for over 20 years. Most of the research to date has focused on single link, fixed length, single plane of vibration test beds. In addition, actuation has been predominantly based upon electromagnetic motors. Ironically, these elements are rarely found in the existing industrial long-reach systems. One example is the Modified Light Duty Utility Arm (MLDUA) designed and built by Spar Aerospace for Oak Ridge National Laboratory (ORNL). This arm operates in larger, underground waste storage tanks located at ORNL. The size and nature of the tanksmore » require that the robot have a reach of approximately 15 ft and a payload capacity of 250 lb. In order to achieve these criteria, each joint is hydraulically actuated. Furthermore, the robot has a prismatic degree-of-freedom to ease deployment. When fully extended, the robot`s first natural frequency is 1.76 Hz. Many of the projected tasks, coupled with the robot`s flexibility, present an interesting problem. How will many of the existing flexure control algorithms perform on a hydraulic, long-reach manipulator with prismatic links? To minimize cost and risk of testing these algorithms on the MLDUA, the authors have designed a new test bed that contains many of the same elements. This manuscript described a new hydraulically actuated, long-reach manipulator with a flexible prismatic link at ORNL. Focus is directed toward both modeling and control of hydraulic actuators as well as flexible links that have variable natural frequencies.« less

Coping and back problems: analysis of multiple data sources on an entire cross-sectional cohort of Swedish military recruits.

PubMed

Leboeuf-Yde, Charlotte; Larsen, Kristian; Ahlstrand, Ingvar; Volinn, Ernest

2006-05-03

As the literature now stands, a bewildering number and variety of biological, psychological and social factors are, apparently, implicated in back problems. However, if and how these have a direct influence on back problems is not clear. Obesity, for example, has in many studies been shown to be associated with back problems but there is no evidence for a causal link. This could be explained by a dearth of suitably designed studies but also because obesity may be but a proxy for some other, truly explanatory variable. Coping has been linked with, particularly, persistent back problems as well as with health in general. The question is, whether coping could be the explanatory link between, for example, these two variables. A cross-sectional study was undertaken using data from the Swedish Army, consisting of the entire cohort of males (N = 48,502) summoned in 1998 to serve in the military. The purpose of the study was to investigate the relation between five independent variables and two dependent variables ("outcome variables"). The independent variables were two anthropomorphic variables (height and body mass index), two psychological variables (intellectual capacity and coping in relation to stress), and one social variable (type of education). The two outcome variables were back problems and ill health. In particular, we wanted to determine whether controlling for coping would affect the associations between the other four independent variables and the two outcome variables. Data for the analysis come from a battery of standardized examinations, including medical examinations, a test of intellectual capacity, and a test of coping in relation to stress. Each of these examinations was conducted independently of the others. Unadjusted and adjusted odds ratios were calculated for the outcome variables of back problems and ill health. The associations between height, body mass index, intellectual capacity, type of education and the two outcome variables (back problems and ill health) were weak to moderate. Additionally, there were strong associations between coping and the two outcome variables and when controlling for coping the previously noted associations diminished or disappeared, whereas none of the other variables had a large effect on the association between coping and the two outcome variables. Coping emerged as strongly associated with both back problem and ill health and coping had a leveling effect on the associations between the other independent variables and the two outcome variables. This study is noteworthy particularly because the association with coping is so robust. It is a retrospective, cross-sectional study, however, and, as such it raises questions of causality; which - if any - came first, inability to cope or back pain? The results of this study call attention to the need for a prospective study, in which coping is clearly defined. Such a study has been undertaken and will be presented separately. Index terms: back pain, coping, education, height, BMI, intellectual capacity, bio-psycho-social model, epidemiology, cohort, cross-sectional study.

NASA Langley Atmospheric Science Data Center Toolsets for Airborne Data (TAD): Common Variable Naming Schema

NASA Astrophysics Data System (ADS)

Chen, G.; Early, A. B.; Peeters, M. C.

2014-12-01

NASA has conducted airborne tropospheric chemistry studies for about three decades. These field campaigns have generated a great wealth of observations, which are characterized by a wide range of trace gases and aerosol properties. The airborne observational data have often been used in assessment and validation of models and satellite instruments. One particular issue is a lack of consistent variable naming across field campaigns, which makes cross-mission data discovery difficult. The ASDC Toolset for Airborne Data (TAD) is being designed to meet the user community needs for manipulating aircraft data for scientific research on climate change and air quality relevant issues. As part of this effort, a common naming system was developed to provide a link between variables from different aircraft field studies. This system covers all current and past airborne in-situ measurements housed at the ASDC, as well as select NOAA missions. The TAD common variable naming system consists of 6 categories and 3 sub-levels. The top-level category is primarily defined by the physical characteristics of the measurement: e.g., aerosol, cloud, trace gases. The sub-levels were designed to organize the variables according to nature of measurement (e.g., aerosol microphysical and optical properties) or chemical structures (e.g., carbon compound). The development of the TAD common variable naming system was in consultation with staff from the Global Change Master Directory (GCMD) and referenced/expanded the existing Climate and Forecast (CF) variable naming conventions. The detailed structure of the TAD common variable naming convention and its application in TAD development will be presented.

An hourly variation in zoo visitor interest: measurement and significance for animal welfare research.

PubMed

Davey, Gareth

2006-01-01

A methodological difficulty facing welfare research on nonhuman animals in the zoo is the large number of uncontrolled variables due to variation within and between study sites. Zoo visitors act as uncontrolled variables, with number, density, size, and behavior constantly changing. This is worrisome because previous research linked visitor variables to animal behavioral changes indicative of stress. There are implications for research design: Studies not accounting for visitors' effect on animal welfare risk confounding (visitor) variables distorting their findings. Zoos need methods to measure and minimize effects of visitor behavior and to ensure that there are no hidden variables in research models. This article identifies a previously unreported variable--hourly variation (decrease) in visitor interest--that may impinge on animal welfare and validates a methodology for measuring it. That visitor interest wanes across the course of the day has important implications for animal welfare management; visitor effects on animal welfare are likely to occur, or intensify, during the morning or in earlier visits when visitor interest is greatest. This article discusses this issue and possible solutions to reduce visitor effects on animal well-being.

The role of the media in body image concerns among women: a meta-analysis of experimental and correlational studies.

PubMed

Grabe, Shelly; Ward, L Monique; Hyde, Janet Shibley

2008-05-01

Research suggests that exposure to mass media depicting the thin-ideal body may be linked to body image disturbance in women. This meta-analysis examined experimental and correlational studies testing the links between media exposure to women's body dissatisfaction, internalization of the thin ideal, and eating behaviors and beliefs with a sample of 77 studies that yielded 141 effect sizes. The mean effect sizes were small to moderate (ds = -.28, -.39, and -.30, respectively). Effects for some outcome variables were moderated by publication year and study design. The findings support the notion that exposure to media images depicting the thin-ideal body is related to body image concerns for women. (Copyright) 2008 APA, all rights reserved.

The Invisible Link: Using State Space Representations to Investigate the Connection between Variables and Their Referents

ERIC Educational Resources Information Center

Pollack, Courtney

2012-01-01

The ability to represent numerical quantities in symbolic form is a necessary foundation for mathematical competence. Variables are particularly important symbolic representations for learning algebra and succeeding in higher mathematics, but the mechanisms of how students link a variable to what it represents are not well understood. Research…

Selection of single chain antibody fragments binding to the extracellular domain of 4-1BB receptor by phage display technology.

PubMed

Bagheri, Salman; Yousefi, Mehdi; Safaie Qamsari, Elmira; Riazi-Rad, Farhad; Abolhassani, Mohsen; Younesi, Vahid; Dorostkar, Ruhollah; Movassaghpour, Ali Akbar; Sharifzadeh, Zahra

2017-03-01

The 4-1BB is a surface glycoprotein that pertains to the tumor necrosis factor-receptor family. There is compelling evidence suggesting important roles for 4-1BB in the immune response, including cell activation and proliferation and also cytokine induction. Because of encouraging results of different agonistic monoclonal antibodies against 4-1BB in the treatment of cancer, infectious, and autoimmune diseases, 4-1BB has been suggested as an attractive target for immunotherapy. In this study, single chain variable fragment phage display libraries, Tomlinson I+J, were screened against specific synthetic oligopeptides (peptides I and II) designed from 4-1BB extracellular domain. Five rounds of panning led to selection of four 4-1BB specific single chain variable fragments (PI.12, PI.42, PII.16, and PII.29) which showed specific reaction to relevant peptides in phage enzyme-linked immunosorbent assay. The selected clones were successfully expressed in Escherichia coli Rosetta-gami 2, and their expression was confirmed by western blot analysis. Enzyme-linked immunosorbent assay experiments indicated that these antibodies were able to specifically recognize 4-1BB without any cross-reactivity with other antigens. Flow cytometry analysis demonstrated an acceptable specific binding of the single chain variable fragments to 4-1BB expressed on CCRF-CEM cells, while no binding was observed with an irrelevant antibody. Anti-4-1BB single chain variable fragments enhanced surface CD69 expression and interleukin-2 production in stimulated CCRF-CEM cells which confirmed the agonistic effect of the selected single chain variable fragments. The data from this study have provided a rationale for further experiments involving the biological functions of anti-4-1BB single chain variable fragments in future studies.

Ordinal probability effect measures for group comparisons in multinomial cumulative link models.

PubMed

Agresti, Alan; Kateri, Maria

2017-03-01

We consider simple ordinal model-based probability effect measures for comparing distributions of two groups, adjusted for explanatory variables. An "ordinal superiority" measure summarizes the probability that an observation from one distribution falls above an independent observation from the other distribution, adjusted for explanatory variables in a model. The measure applies directly to normal linear models and to a normal latent variable model for ordinal response variables. It equals Φ(β/2) for the corresponding ordinal model that applies a probit link function to cumulative multinomial probabilities, for standard normal cdf Φ and effect β that is the coefficient of the group indicator variable. For the more general latent variable model for ordinal responses that corresponds to a linear model with other possible error distributions and corresponding link functions for cumulative multinomial probabilities, the ordinal superiority measure equals exp(β)/[1+exp(β)] with the log-log link and equals approximately exp(β/2)/[1+exp(β/2)] with the logit link, where β is the group effect. Another ordinal superiority measure generalizes the difference of proportions from binary to ordinal responses. We also present related measures directly for ordinal models for the observed response that need not assume corresponding latent response models. We present confidence intervals for the measures and illustrate with an example. © 2016, The International Biometric Society.

Systems effects on family planning innovativeness.

PubMed

Lee, S B

1983-12-01

Data from Korea were used to explore the importance of community level variables in explaining family planning adoption at the individual level. An open system concept was applied, assuming that individual family planning behavior is influenced by both environmental and individual factors. The environmental factors were measured at the village level and designated as community characteristics. The dimension of communication network variables was introduced. Each individual was characterized in terms of the degree of her involvement in family planning communication with others in her village. It was assumed that the nature of the communication network linking individuals with each other effects family planning adoption at the individual level. Specific objectives were to determine 1) the relative importance of the specific independent variables in explaining family planning adoption and 2) the relative importance of the community level variables in comparison with the individual level variables in explaining family planning adoption at the individual level. The data were originally gathered in a 1973 research project on Korea's mothers' clubs. 1047 respondents were interviewed, comprising all married women in 25 sample villages having mothers' clubs. The dependent variable was family planning adoption behavior, defined as current use of any of the modern methods of family planning. The independent variables were defined at 3 levels: individual, community, and at a level intermediate between them involving communication links between individuals. More of the individual level independent variables were significantly correlated with the dependent variables than the community level variables. Among those variables with statistically significant correlations, the correlation coefficients were consistently higher for the individual level than for the community level variables. More of the variance in the dependent variable was explained by individual level than by community level variables. Community level variables accounted for only about 2.5% of the total variance in the dependent variable, in marked contrast to the result showing individual level variables accounting for as much as 19% of the total variance. When both individual and community level variables were entered into a multiple correlation analysis, a multiple correlation coefficient of .4714 was obtained together they explained about 20% of the total variance. The 2 communication network variables--connectedness and integrativeness--were correlated with the dependent variable at much higher levels than most of the individual or community level variables. Connectedness accounted for the greatest amount of the total variance. The communication network variables as a group explained as much of the total variance in the dependent variable as the individual level variables and greatly more that the community level variables.

Computational wing optimization and comparisons with experiment for a semi-span wing model

NASA Technical Reports Server (NTRS)

Waggoner, E. G.; Haney, H. P.; Ballhaus, W. F.

1978-01-01

A computational wing optimization procedure was developed and verified by an experimental investigation of a semi-span variable camber wing model in the NASA Ames Research Center 14 foot transonic wind tunnel. The Bailey-Ballhaus transonic potential flow analysis and Woodward-Carmichael linear theory codes were linked to Vanderplaats constrained minimization routine to optimize model configurations at several subsonic and transonic design points. The 35 deg swept wing is characterized by multi-segmented leading and trailing edge flaps whose hinge lines are swept relative to the leading and trailing edges of the wing. By varying deflection angles of the flap segments, camber and twist distribution can be optimized for different design conditions. Results indicate that numerical optimization can be both an effective and efficient design tool. The optimized configurations had as good or better lift to drag ratios at the design points as the best designs previously tested during an extensive parametric study.

Robust stability of second-order systems

NASA Technical Reports Server (NTRS)

Chuang, C.-H.

1993-01-01

A feedback linearization technique is used in conjunction with passivity concepts to design robust controllers for space robots. It is assumed that bounded modeling uncertainties exist in the inertia matrix and the vector representing the coriolis, centripetal, and friction forces. Under these assumptions, the controller guarantees asymptotic tracking of the joint variables. A Lagrangian approach is used to develop a dynamic model for space robots. Closed-loop simulation results are illustrated for a simple case of a single link planar manipulator with freely floating base.

Continuous-Variable Measurement-Device-Independent Multipartite Quantum Communication Using Coherent States

NASA Astrophysics Data System (ADS)

Zhou, Jian; Guo, Ying

2017-02-01

A continuous-variable measurement-device-independent (CV-MDI) multipartite quantum communication protocol is designed to realize multipartite communication based on the GHZ state analysis using Gaussian coherent states. It can remove detector side attack as the multi-mode measurement is blindly done in a suitable Black Box. The entanglement-based CV-MDI multipartite communication scheme and the equivalent prepare-and-measurement scheme are proposed to analyze the security and guide experiment, respectively. The general eavesdropping and coherent attack are considered for the security analysis. Subsequently, all the attacks are ascribed to coherent attack against imperfect links. The asymptotic key rate of the asymmetric configuration is also derived with the numeric simulations illustrating the performance of the proposed protocol.

A User’s Guide for LOGATAK. A Simulation Model to Analyze Logistic Network Distribution and Interdiction,

DTIC Science & Technology

1981-04-15

BLANK ADD LINK DATA TO LIBRARY 0 DELETE LINK DATA FROM LIBRARY C CHANGE ONE OR MORE VARIABLES OF DEFINED LINK IN LIBARY 25 ALTERATIONST...DELETE TERMINAL DATA FROM LIBRARY C CHANGE ONE OR MORE VARIABLES OF OEFINED TERMINAL IN LIBARY Unlike link data only one card is needed to change the...sector data cards identify the sets of data to be selected from the data library. Each data set is defined by a five digit number. The first four digits

Selected options supporting use of the group embedded figures test in modeling achievement in clinical laboratory science programs.

PubMed

Powell, M E

1995-01-01

To identify, in light of predicted future shortages of allied-health personnel, student and curricular characteristics of clinical laboratory science (CLS) programs relevant to recruitment and retention at the baccalaureate level. Not applicable. Not applicable. Options for modeling achievement in CLS programs are developed, and designs and procedures for clarifying procedural questions are considered in a context of delivery of instruction for specialized curricula and skill development. Considerable attention is given to the potential for using the Group Embedded Figures Test (GEFT) in modeling, advising, designing curricula, and monitoring quality improvement of programs and graduates. Not applicable. Supporting evidence is supplied from the literature for options in developing an appropriate model for examining those salient variables known to have linkages to achievement. An argument is presented for better understanding of antecedent variables affecting achievement and retention of CLS students. In addition, a case is made for development of an appropriate model examining variables identified in the literature as being linked to achievement. Dynamic models based on these considerations should be developed chronologically from entry through graduation with emphasis on growth at year-end milestones.

Variability in case-mix adjusted in-hospital cardiac arrest rates.

PubMed

Merchant, Raina M; Yang, Lin; Becker, Lance B; Berg, Robert A; Nadkarni, Vinay; Nichol, Graham; Carr, Brendan G; Mitra, Nandita; Bradley, Steven M; Abella, Benjamin S; Groeneveld, Peter W

2012-02-01

It is unknown how in-hospital cardiac arrest (IHCA) rates vary across hospitals and predictors of variability. Measure variability in IHCA across hospitals and determine if hospital-level factors predict differences in case-mix adjusted event rates. Get with the Guidelines Resuscitation (GWTG-R) (n=433 hospitals) was used to identify IHCA events between 2003 and 2007. The American Hospital Association survey, Medicare, and US Census were used to obtain detailed information about GWTG-R hospitals. Adult patients with IHCA. Case-mix-adjusted predicted IHCA rates were calculated for each hospital and variability across hospitals was compared. A regression model was used to predict case-mix adjusted event rates using hospital measures of volume, nurse-to-bed ratio, percent intensive care unit beds, palliative care services, urban designation, volume of black patients, income, trauma designation, academic designation, cardiac surgery capability, and a patient risk score. We evaluated 103,117 adult IHCAs at 433 US hospitals. The case-mix adjusted IHCA event rate was highly variable across hospitals, median 1/1000 bed days (interquartile range: 0.7 to 1.3 events/1000 bed days). In a multivariable regression model, case-mix adjusted IHCA event rates were highest in urban hospitals [rate ratio (RR), 1.1; 95% confidence interval (CI), 1.0-1.3; P=0.03] and hospitals with higher proportions of black patients (RR, 1.2; 95% CI, 1.0-1.3; P=0.01) and lower in larger hospitals (RR, 0.54; 95% CI, 0.45-0.66; P<0.0001). Case-mix adjusted IHCA event rates varied considerably across hospitals. Several hospital factors associated with higher IHCA event rates were consistent with factors often linked with lower hospital quality of care.

Attitude similarity and familiarity and their links to mental health: An examination of potential interpersonal mediators.

PubMed

Moore, Shannon M; Uchino, Bert N; Baucom, Brian R W; Behrends, Arwen A; Sanbonmatsu, David

2017-01-01

Similarity and familiarity with partner's attitudes are linked to positive relationship outcomes, while interpersonal variables have been linked to mental health. Using multilevel models (MLMs), we modeled the associations between these attitudinal variables and mental health outcomes in 74 married couples. We found that higher levels of attitude similarity in couples were linked to lower depression, while higher levels of attitude familiarity in couples were associated with greater satisfaction with life. Mediational analyses indicated marital satisfaction and interpersonal stress mediated the link between attitude similarity and depression. Marital satisfaction also mediated the link between familiarity and satisfaction with life. This study is the first linking attitude familiarity to mental health and provides evidence that familiarity and similarity have mental health effects partly due to their interpersonal consequences.

Process, mechanism, and explanation related to externalizing behavior in developmental psychopathology.

PubMed

Hinshaw, Stephen P

2002-10-01

Advances in conceptualization and statistical modeling, on the one hand, and enhanced appreciation of transactional pathways, gene-environment correlations and interactions, and moderator and mediator variables, on the other, have heightened awareness of the need to consider factors and processes that explain the development and maintenance of psychopathology. With a focus on attentional problems, impulsivity, and disruptive behavior patterns, I address the kinds of conceptual approaches most likely to lead to advances regarding explanatory models in the field. Findings from my own research program on processes and mechanisms reveal both promise and limitations. Progress will emanate from use of genetically informative designs, blends of variable and person-centered research, explicit testing of developmental processes, systematic approaches to moderation and mediation, exploitation of "natural experiments," and the conduct of prevention and intervention trials designed to accentuate explanation as well as outcome. In all, breakthroughs will occur only with advances in translational research-linking basic and applied science-and with the further development of transactional, systemic approaches to explanation.

High-Volume Production of Lightweight Multijunction Solar Cells

NASA Technical Reports Server (NTRS)

Youtsey, Christopher

2015-01-01

MicroLink Devices, Inc., has transitioned its 6-inch epitaxial lift-off (ELO) solar cell fabrication process into a manufacturing platform capable of sustaining large-volume production. This Phase II project improves the ELO process by reducing cycle time and increasing the yield of large-area devices. In addition, all critical device fabrication processes have transitioned to 6-inch production tool sets designed for volume production. An emphasis on automated cassette-to-cassette and batch processes minimizes operator dependence and cell performance variability. MicroLink Devices established a pilot production line capable of at least 1,500 6-inch wafers per month at greater than 80 percent yield. The company also increased the yield and manufacturability of the 6-inch reclaim process, which is crucial to reducing the cost of the cells.

Workstations take over conceptual design

NASA Technical Reports Server (NTRS)

Kidwell, George H.

1987-01-01

Workstations provide sufficient computing memory and speed for early evaluations of aircraft design alternatives to identify those worthy of further study. It is recommended that the programming of such machines permit integrated calculations of the configuration and performance analysis of new concepts, along with the capability of changing up to 100 variables at a time and swiftly viewing the results. Computations can be augmented through links to mainframes and supercomputers. Programming, particularly debugging operations, are enhanced by the capability of working with one program line at a time and having available on-screen error indices. Workstation networks permit on-line communication among users and with persons and computers outside the facility. Application of the capabilities is illustrated through a description of NASA-Ames design efforts for an oblique wing for a jet performed on a MicroVAX network.

An application of software design and documentation language. [Galileo spacecraft command and data subsystem

NASA Technical Reports Server (NTRS)

Callender, E. D.; Clarkson, T. B.; Frasier, C. E.

1980-01-01

The software design and documentation language (SDDL) is a general purpose processor to support a lanugage for the description of any system, structure, concept, or procedure that may be presented from the viewpoint of a collection of hierarchical entities linked together by means of binary connections. The language comprises a set of rules of syntax, primitive construct classes (module, block, and module invocation), and language control directives. The result is a language with a fixed grammar, variable alphabet and punctuation, and an extendable vocabulary. The application of SDDL to the detailed software design of the Command Data Subsystem for the Galileo Spacecraft is discussed. A set of constructs was developed and applied. These constructs are evaluated and examples of their application are considered.

Ecomorphology and phylogenetic risk: Implications for habitat reconstruction using fossil bovids.

PubMed

Scott, Robert S; Barr, W Andrew

2014-08-01

Reconstructions of paleohabitats are necessary aids in understanding hominin evolution. The morphology of species from relevant sites, understood in terms of functional relationships to habitat (termed ecomorphology), offers a direct link to habitat. Bovids are a speciose radiation that includes many habitat specialists and are abundant in the fossil record. Thus, bovids are extremely common in ecomorphological analyses. However, bovid phylogeny and habitat preference are related, which raises the possibility that analyses linking habitat with morphology are not 'taxon free' but 'taxon-dependent.' Here we analyze eight relative dimensions and one shape index of the metatarsal for a sample of 72 bovid species and one antilocaprid. The selected variables have been previously shown to have strong associations with habitat and to have functional explanations for these associations. Phylogenetic generalized least squares analyses of these variables, including habitat and size, resulted in estimates for the parameter lambda (used to model phylogenetic signal) varying from zero to one. Thus, while phylogeny, morphology, and habitat all march together among the bovids, the odds that phylogeny confounds ecomorphological analyses may vary depending on particular morphological characteristics. While large values of lambda do not necessarily indicate that habitat differences are unimportant drivers of morphology, we consider the low value of lambda for relative metatarsal width suggestive that conclusions about habitat built on observations of this particular morphology carry with them less 'phylogenetic risk.' We suggest that the way forward for ecomorphology is grounded in functionally relevant observations and careful consideration of phylogeny designed to bracket probable habitat preferences appropriately. Separate consideration of different morphological variables may help to determine the level of 'phylogenetic risk' attached to conclusions linking habitat and morphology. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analysis of Links Positions in Landing Gear Mechanism

NASA Astrophysics Data System (ADS)

Brewczyński, D.; Tora, G.

2014-08-01

This article contains a kinematic analysis of an aircraft chassis mechanism in a range of positions. The mechanism of the chassis is made up of several smaller subsystems with different functions. The first mechanism is used to eject the chassis before landing (touchdown) and fold it to hatchway after the lift off. The second mechanism is designed to perform rotation of the crossover with the wheel, in order to adjust the position of the wheel to fit it in the limited space in the hold. The third mechanism allows movement of the chassis resulting from the change in length of the damper. To determine the position of the following links of the mechanism calculus of vectors was applied in which unit vectors were used to represent the angular position of the links. The aim of the analysis is to determine the angle of convergence and the angle of heel wheels as a function of the variable length of hydraulic cylinder, length of the shock absorber, length of the regulations rods

Evaluation of Bluetooth communications for the deployment of assisted living technologies in home environments.

PubMed

McGrath, Michael J; Burns, Adrian; Dishongh, Terry

2007-01-01

Using five different commercially available class one and class two Bluetooth dongles a total of seven homes which represented a cross section of typical Irish homes were surveyed to determine the effect of construction methods, house size, sensor placement, host placement, antenna design and RF interference had on the link quality of Bluetooth enabled sensors. The results obtained indicates there is high variability in the link quality which is determined by the quality of the BT radio, placement of the antenna on both the master and slave, the number of walls which must be penetrated and the construction materials used in the wall. The placement of the sensor was the single biggest factor in determining the link quality. The type of construction used in the interior walls has significant influence also. The final factor of significant influence was the type of antenna used on the Bluetooth dongle. The use of an external antenna gave significantly better range performance than an internal antenna.

Types of prayer and depressive symptoms among cancer patients: the mediating role of rumination and social support

PubMed Central

Smith, Amy Rex; Norris, Rebecca L.; Canenguez, Katia M.; Tracey, Elizabeth F.; DeCristofaro, Susan B.

2014-01-01

We examined the association between different types of prayer and depressive symptoms—with rumination and social support as potential mediators—in a sample of predominantly White, Christian, and female ambulatory cancer patients. In a cross-sectional design, 179 adult cancer outpatients completed measures of prayer, rumination, social support, depressive symptoms, and demographic variables. Type and stage of cancer were collected from electronic medical charts. Depressive symptoms were negatively correlated with adoration prayer (r = −.15), reception prayer (r = −.17), thanksgiving prayer (r = −.29), and prayer for the well-being of others (r = −.26). In the path analysis, rumination fully mediated the link between thanksgiving prayer and depressive symptoms (β for indirect effect = −.05), whereas social support partially mediated the link between prayer for others and depressive symptoms (β for indirect effect = −.05). These findings suggest that unique mechanisms may link different prayer types to lower depressive symptoms among cancer patients. PMID:21487725

System-level power optimization for real-time distributed embedded systems

NASA Astrophysics Data System (ADS)

Luo, Jiong

Power optimization is one of the crucial design considerations for modern electronic systems. In this thesis, we present several system-level power optimization techniques for real-time distributed embedded systems, based on dynamic voltage scaling, dynamic power management, and management of peak power and variance of the power profile. Dynamic voltage scaling has been widely acknowledged as an important and powerful technique to trade off dynamic power consumption and delay. Efficient dynamic voltage scaling requires effective variable-voltage scheduling mechanisms that can adjust voltages and clock frequencies adaptively based on workloads and timing constraints. For this purpose, we propose static variable-voltage scheduling algorithms utilizing criticalpath driven timing analysis for the case when tasks are assumed to have uniform switching activities, as well as energy-gradient driven slack allocation for a more general scenario. The proposed techniques can achieve closeto-optimal power savings with very low computational complexity, without violating any real-time constraints. We also present algorithms for power-efficient joint scheduling of multi-rate periodic task graphs along with soft aperiodic tasks. The power issue is addressed through both dynamic voltage scaling and power management. Periodic task graphs are scheduled statically. Flexibility is introduced into the static schedule to allow the on-line scheduler to make local changes to PE schedules through resource reclaiming and slack stealing, without interfering with the validity of the global schedule. We provide a unified framework in which the response times of aperiodic tasks and power consumption are dynamically optimized simultaneously. Interconnection network fabrics point to a new generation of power-efficient and scalable interconnection architectures for distributed embedded systems. As the system bandwidth continues to increase, interconnection networks become power/energy limited as well. Variable-frequency links have been designed by circuit designers for both parallel and serial links, which can adaptively regulate the supply voltage of transceivers to a desired link frequency, to exploit the variations in bandwidth requirement for power savings. We propose solutions for simultaneous dynamic voltage scaling of processors and links. The proposed solution considers real-time scheduling, flow control, and packet routing jointly. It can trade off the power consumption on processors and communication links via efficient slack allocation, and lead to more power savings than dynamic voltage scaling on processors alone. For battery-operated systems, the battery lifespan is an important concern. Due to the effects of discharge rate and battery recovery, the discharge pattern of batteries has an impact on the battery lifespan. Battery models indicate that even under the same average power consumption, reducing peak power current and variance in the power profile can increase the battery efficiency and thereby prolong battery lifetime. To take advantage of these effects, we propose battery-driven scheduling techniques for embedded applications, to reduce the peak power and the variance in the power profile of the overall system under real-time constraints. The proposed scheduling algorithms are also beneficial in addressing reliability and signal integrity concerns by effectively controlling peak power and variance of the power profile.

Multilevel and Latent Variable Modeling with Composite Links and Exploded Likelihoods

ERIC Educational Resources Information Center

Rabe-Hesketh, Sophia; Skrondal, Anders

2007-01-01

Composite links and exploded likelihoods are powerful yet simple tools for specifying a wide range of latent variable models. Applications considered include survival or duration models, models for rankings, small area estimation with census information, models for ordinal responses, item response models with guessing, randomized response models,…

Design of A Cyclone Separator Using Approximation Method

NASA Astrophysics Data System (ADS)

Sin, Bong-Su; Choi, Ji-Won; Lee, Kwon-Hee

2017-12-01

A Separator is a device installed in industrial applications to separate mixed objects. The separator of interest in this research is a cyclone type, which is used to separate a steam-brine mixture in a geothermal plant. The most important performance of the cyclone separator is the collection efficiency. The collection efficiency in this study is predicted by performing the CFD (Computational Fluid Dynamics) analysis. This research defines six shape design variables to maximize the collection efficiency. Thus, the collection efficiency is set up as the objective function in optimization process. Since the CFD analysis requires a lot of calculation time, it is impossible to obtain the optimal solution by linking the gradient-based optimization algorithm. Thus, two approximation methods are introduced to obtain an optimum design. In this process, an L18 orthogonal array is adopted as a DOE method, and kriging interpolation method is adopted to generate the metamodel for the collection efficiency. Based on the 18 analysis results, the relative importance of each variable to the collection efficiency is obtained through the ANOVA (analysis of variance). The final design is suggested considering the results obtained from two optimization methods. The fluid flow analysis of the cyclone separator is conducted by using the commercial CFD software, ANSYS-CFX.

Examining the influence of link function misspecification in conventional regression models for developing crash modification factors.

PubMed

Wu, Lingtao; Lord, Dominique

2017-05-01

This study further examined the use of regression models for developing crash modification factors (CMFs), specifically focusing on the misspecification in the link function. The primary objectives were to validate the accuracy of CMFs derived from the commonly used regression models (i.e., generalized linear models or GLMs with additive linear link functions) when some of the variables have nonlinear relationships and quantify the amount of bias as a function of the nonlinearity. Using the concept of artificial realistic data, various linear and nonlinear crash modification functions (CM-Functions) were assumed for three variables. Crash counts were randomly generated based on these CM-Functions. CMFs were then derived from regression models for three different scenarios. The results were compared with the assumed true values. The main findings are summarized as follows: (1) when some variables have nonlinear relationships with crash risk, the CMFs for these variables derived from the commonly used GLMs are all biased, especially around areas away from the baseline conditions (e.g., boundary areas); (2) with the increase in nonlinearity (i.e., nonlinear relationship becomes stronger), the bias becomes more significant; (3) the quality of CMFs for other variables having linear relationships can be influenced when mixed with those having nonlinear relationships, but the accuracy may still be acceptable; and (4) the misuse of the link function for one or more variables can also lead to biased estimates for other parameters. This study raised the importance of the link function when using regression models for developing CMFs. Copyright © 2017 Elsevier Ltd. All rights reserved.

TIA: algorithms for development of identity-linked SNP islands for analysis by massively parallel DNA sequencing.

PubMed

Farris, M Heath; Scott, Andrew R; Texter, Pamela A; Bartlett, Marta; Coleman, Patricia; Masters, David

2018-04-11

Single nucleotide polymorphisms (SNPs) located within the human genome have been shown to have utility as markers of identity in the differentiation of DNA from individual contributors. Massively parallel DNA sequencing (MPS) technologies and human genome SNP databases allow for the design of suites of identity-linked target regions, amenable to sequencing in a multiplexed and massively parallel manner. Therefore, tools are needed for leveraging the genotypic information found within SNP databases for the discovery of genomic targets that can be evaluated on MPS platforms. The SNP island target identification algorithm (TIA) was developed as a user-tunable system to leverage SNP information within databases. Using data within the 1000 Genomes Project SNP database, human genome regions were identified that contain globally ubiquitous identity-linked SNPs and that were responsive to targeted resequencing on MPS platforms. Algorithmic filters were used to exclude target regions that did not conform to user-tunable SNP island target characteristics. To validate the accuracy of TIA for discovering these identity-linked SNP islands within the human genome, SNP island target regions were amplified from 70 contributor genomic DNA samples using the polymerase chain reaction. Multiplexed amplicons were sequenced using the Illumina MiSeq platform, and the resulting sequences were analyzed for SNP variations. 166 putative identity-linked SNPs were targeted in the identified genomic regions. Of the 309 SNPs that provided discerning power across individual SNP profiles, 74 previously undefined SNPs were identified during evaluation of targets from individual genomes. Overall, DNA samples of 70 individuals were uniquely identified using a subset of the suite of identity-linked SNP islands. TIA offers a tunable genome search tool for the discovery of targeted genomic regions that are scalable in the population frequency and numbers of SNPs contained within the SNP island regions. It also allows the definition of sequence length and sequence variability of the target region as well as the less variable flanking regions for tailoring to MPS platforms. As shown in this study, TIA can be used to discover identity-linked SNP islands within the human genome, useful for differentiating individuals by targeted resequencing on MPS technologies.

31 CFR 1060.300 - Reporting obligations on foreign bank relationships with Iranian-linked financial institutions...

Code of Federal Regulations, 2012 CFR

2012-07-01

... relationships with Iranian-linked financial institutions designated under IEEPA and IRGC-linked persons... under IEEPA and IRGC-linked persons designated under IEEPA. (a) General. (1) Upon receiving a written... IRGC-linked person designated under IEEPA processed by such foreign bank within the preceding 90...

31 CFR 1060.300 - Reporting obligations on foreign bank relationships with Iranian-linked financial institutions...

Code of Federal Regulations, 2013 CFR

2013-07-01

... relationships with Iranian-linked financial institutions designated under IEEPA and IRGC-linked persons... under IEEPA and IRGC-linked persons designated under IEEPA. (a) General. (1) Upon receiving a written... IRGC-linked person designated under IEEPA processed by such foreign bank within the preceding 90...

31 CFR 1060.300 - Reporting obligations on foreign bank relationships with Iranian-linked financial institutions...

Code of Federal Regulations, 2014 CFR

2014-07-01

... relationships with Iranian-linked financial institutions designated under IEEPA and IRGC-linked persons... under IEEPA and IRGC-linked persons designated under IEEPA. (a) General. (1) Upon receiving a written... IRGC-linked person designated under IEEPA processed by such foreign bank within the preceding 90...

Modeling of Damage Initiation and Progression in a SiC/SiC Woven Ceramic Matrix Composite

NASA Technical Reports Server (NTRS)

Mital, Subodh K.; Goldberg, Robert K.; Bonacuse, Peter J.

2012-01-01

The goal of an ongoing project at NASA Glenn is to investigate the effects of the complex microstructure of a woven ceramic matrix composite and its variability on the effective properties and the durability of the material. Detailed analysis of these complex microstructures may provide clues for the material scientists who `design the material? or to structural analysts and designers who `design with the material? regarding damage initiation and damage propagation. A model material system, specifically a five-harness satin weave architecture CVI SiC/SiC composite composed of Sylramic-iBN fibers and a SiC matrix, has been analyzed. Specimens of the material were serially sectioned and polished to capture the detailed images of fiber tows, matrix and porosity. Open source analysis tools were used to isolate various constituents and finite elements models were then generated from simplified models of those images. Detailed finite element analyses were performed that examine how the variability in the local microstructure affected the macroscopic behavior as well as the local damage initiation and progression. Results indicate that the locations where damage initiated and propagated is linked to specific microstructural features.

Frequency Splitting Analysis and Compensation Method for Inductive Wireless Powering of Implantable Biosensors.

PubMed

Schormans, Matthew; Valente, Virgilio; Demosthenous, Andreas

2016-08-04

Inductive powering for implanted medical devices, such as implantable biosensors, is a safe and effective technique that allows power to be delivered to implants wirelessly, avoiding the use of transcutaneous wires or implanted batteries. Wireless powering is very sensitive to a number of link parameters, including coil distance, alignment, shape, and load conditions. The optimum drive frequency of an inductive link varies depending on the coil spacing and load. This paper presents an optimum frequency tracking (OFT) method, in which an inductive power link is driven at a frequency that is maintained at an optimum value to ensure that the link is working at resonance, and the output voltage is maximised. The method is shown to provide significant improvements in maintained secondary voltage and system efficiency for a range of loads when the link is overcoupled. The OFT method does not require the use of variable capacitors or inductors. When tested at frequencies around a nominal frequency of 5 MHz, the OFT method provides up to a twofold efficiency improvement compared to a fixed frequency drive. The system can be readily interfaced with passive implants or implantable biosensors, and lends itself to interfacing with designs such as distributed implanted sensor networks, where each implant is operating at a different frequency.

A review of variables of urban street connectivity for spatial connection

NASA Astrophysics Data System (ADS)

Mohamad, W. S. N. W.; Said, I.

2014-02-01

Several studies on street connectivity in cities and towns have been modeled on topology, morphology, technology and psychology of people living in the urban environment. Street connectivity means the connection of streets that offers people alternative routes. However, there emerge difficulties to determine the suitable variables and analysis to be chosen in defining the accurate result for studies street connectivity. The aim of this paper is to identify variables of street connectivity by applying GIS and Space Syntax. This paper reviews the variables of street connectivity from 15 past articles done in 1990s to early 2000s from journals of nine disciplines on Environment and Behavior, Planning and Design, Computers, Environment and Urban Systems, Applied Earth Observation and Geo-information, Environment and Planning, Physica A: Statistical Mechanics and its Applications, Environmental Psychology, Social Science and Medicine and Building and Environment. From the review, there are four variables found for street connectivity: link (streets-streets, street-nodes or node-streets, nodes-nodes), accessibility, least-angle, and centrality. Space syntax and GIS are suitable tools to analyze the four variables relating to systematic street systems for pedestrians. This review implies that planners of the street systems, in the aspect of street connectivity in cities and towns, should consider these four variables.

Integrating Decision Making and Mental Health Interventions Research: Research Directions

PubMed Central

Wills, Celia E.; Holmes-Rovner, Margaret

2006-01-01

The importance of incorporating patient and provider decision-making processes is in the forefront of the National Institute of Mental Health (NIMH) agenda for improving mental health interventions and services. Key concepts in patient decision making are highlighted within a simplified model of patient decision making that links patient-level/“micro” variables to services-level/“macro” variables via the decision-making process that is a target for interventions. The prospective agenda for incorporating decision-making concepts in mental health research includes (a) improved measures for characterizing decision-making processes that are matched to study populations, complexity, and types of decision making; (b) testing decision aids in effectiveness research for diverse populations and clinical settings; and (c) improving the understanding and incorporation of preference concepts in enhanced intervention designs. PMID:16724158

Perceived Discrimination among African American Adolescents and Allostatic Load: A Longitudinal Analysis with Buffering Effects

PubMed Central

Brody, Gene H.; Lei, Man-Kit; Chae, David H.; Yu, Tianyi; Kogan, Steven M.; Beach, Steven R. H.

2013-01-01

This study was designed to examine the prospective relations of perceived racial discrimination with allostatic load (AL), along with a possible buffer of the association. A sample of 331 African Americans in the rural South provided assessments of perceived discrimination from ages 16 to 18 years. When youths were 18, caregivers reported parental emotional support, and youths assessed peer emotional support. AL and potential confounder variables were assessed when youths were 20. Latent Growth Mixture Modeling identified two perceived discrimination classes: high and stable and low and increasing. Adolescents in the high and stable class evinced heightened AL even with confounder variables controlled. The racial discrimination to AL link was not significant for young adults who received high emotional support. PMID:24673162

78 FR 42589 - Additional Designations, Foreign Narcotics Kingpin Designation Act

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-16

...) [SDNTK] (Linked To: ISSA EMPRESA UNIPERSONAL; Linked To: INVERSIONES GILFE S.A.; Linked To: INDUITEX LTDA...: INDUITEX LTDA.; Linked To: INVERSIONES GILFE S.A.; Linked To: ORBITAL HORIZONS CORP.; Linked To: FUNDACION... INVESTMENT INC.; Linked To: SBT S.A.; Linked To: ISSA EMPRESA UNIPERSONAL; Linked To: INVERSIONES GILFE S.A...

Attitude Similarity and Familiarity and Their Links to Mental Health: An Examination of Potential Interpersonal Mediators

PubMed Central

Uchino, Bert; Baucom, Brian; Behrends, Arwen; Sanbonmatsu, David

2017-01-01

Similarity and familiarity with partner's attitudes (Byrne, Clore, & Smeaton, 1986; Sanbonmatsu, Uchino, & Birmingham, 2011) are linked to positive relationship outcomes, while interpersonal variables have been linked to mental health (e.g., Lakey & Cronin, 2008). Using multilevel models (MLMs), we modeled the associations between these attitudinal variables and mental health outcomes in 74 married couples. We found that higher levels of attitude similarity in couples were linked to lower depression, while higher levels of attitude familiarity in couples were associated with greater satisfaction with life. Mediational analyses indicated marital satisfaction and interpersonal stress mediated the link between attitude similarity and depression. Marital satisfaction also mediated the link between familiarity and satisfaction with life. This study is the first linking attitude familiarity to mental health and provides evidence that familiarity and similarity have mental health effects partly due to their interpersonal consequences. PMID:27065059

Intergenic Sequence Ribotyping using a region neighboring dkgB links genovar to Kauffman-White serotype of Salmonella enterica

USDA-ARS?s Scientific Manuscript database

Previous research identified that the 5S ribosomal (rrn) gene and associated flanking sequences that are closely linked to the dkgB gene of Salmonella enterica were highly variable between serotypes, but not between subpopulations within the same serotype (PMID: 17005008). The degree of variability ...

Long-acting follicle-stimulating hormone analogs containing N-linked glycosylation exhibited increased bioactivity compared with o-linked analogs in female rats.

PubMed

Weenen, C; Peña, J E; Pollak, S V; Klein, J; Lobel, L; Trousdale, R K; Palmer, S; Lustbader, E G; Ogden, R T; Lustbader, J W

2004-10-01

The effects of altering the number and type of additional carbohydrate moieties on the pharmacokinetic and pharmacodynamic properties of FSH were examined in this report. A series of single-chain follitropins, containing variable numbers of additional N- (or O-) linked carbohydrates, were designed and expressed in Chinese hamster ovary cells. Proper folding, efficient receptor binding, and signal transduction were confirmed by in vitro assays. Pharmacokinetic and pharmacodynamic parameters were evaluated in immature female Sprague Dawley rats. Increasing the number of glycosylation sites with either N- (or O-) linked moieties extended the elimination half-life as much as 2-fold compared with recombinant human FSH (rhFSH). However, there was a maximum elimination half-life such that further glycosylation provided no additional lengthening of the half-life. Conversely, biopotency, as assessed by inhibin A levels 74 h post injection, and follicle production were significantly higher for the N-linked analogs. Rats stimulated with the longest acting analogs (either N- or O-linked) showed significantly higher ovarian weights than rats receiving a single injection of rhFSH. The analog containing four additional N-linked sites (rhFSH-N4) had the greatest number of large, preovulatory follicles. Although the half-life of rhFSH-N4 displayed no further enhancement beyond the other longest acting analogs, this analog exhibited significantly increased biopotency in rats. This work provides the basis for the generation of a series of reagents potentially useful for therapeutic applications.

Microeconomics of advanced process window control for 50-nm gates

NASA Astrophysics Data System (ADS)

Monahan, Kevin M.; Chen, Xuemei; Falessi, Georges; Garvin, Craig; Hankinson, Matt; Lev, Amir; Levy, Ady; Slessor, Michael D.

2002-07-01

Fundamentally, advanced process control enables accelerated design-rule reduction, but simple microeconomic models that directly link the effects of advanced process control to profitability are rare or non-existent. In this work, we derive these links using a simplified model for the rate of profit generated by the semiconductor manufacturing process. We use it to explain why and how microprocessor manufacturers strive to avoid commoditization by producing only the number of dies required to satisfy the time-varying demand in each performance segment. This strategy is realized using the tactic known as speed binning, the deliberate creation of an unnatural distribution of microprocessor performance that varies according to market demand. We show that the ability of APC to achieve these economic objectives may be limited by variability in the larger manufacturing context, including measurement delays and process window variation.

Application of a case-control study design to investigate genotypic signatures of HIV-1 transmission.

PubMed

Mota, Talia M; Murray, John M; Center, Rob J; Purcell, Damian F J; McCaw, James M

2012-06-25

The characterization of HIV-1 transmission strains may inform the design of an effective vaccine. Shorter variable loops with fewer predicted glycosites have been suggested as signatures enriched in envelope sequences derived during acute HIV-1 infection. Specifically, a transmission-linked lack of glycosites within the V1 and V2 loops of gp120 provides greater access to an α4β7 binding motif, which promotes the establishment of infection. Also, a histidine at position 12 in the leader sequence of Env has been described as a transmission signature that is selected against during chronic infection. The purpose of this study is to measure the association of the presence of an α4β7 binding motif, the number of N-linked glycosites, the length of the variable loops, and the prevalence of histidine at position 12 with HIV-1 transmission. A case-control study design was used to measure the prevalence of these variables between subtype B and C transmission sequences and frequency-matched randomly-selected sequences derived from chronically infected controls. Subtype B transmission strains had shorter V3 regions than chronic strains (p = 0.031); subtype C transmission strains had shorter V1 loops than chronic strains (p = 0.047); subtype B transmission strains had more V3 loop glycosites (p = 0.024) than chronic strains. Further investigation showed that these statistically significant results were unlikely to be biologically meaningful. Also, there was no difference observed in the prevalence of a histidine at position 12 among transmission strains and controls of either subtype. Although a genetic bottleneck is observed after HIV-1 transmission, our results indicate that summary characteristics of Env hypothesised to be important in transmission are not divergent between transmission and chronic strains of either subtype. The success of a transmission strain to initiate infection may be a random event from the divergent pool of donor viral sequences. The characteristics explored through this study are important, but may not function as genotypic signatures of transmission as previously described.

Testing the accuracy of redshift-space group-finding algorithms

NASA Astrophysics Data System (ADS)

Frederic, James J.

1995-04-01

Using simulated redshift surveys generated from a high-resolution N-body cosmological structure simulation, we study algorithms used to identify groups of galaxies in redshift space. Two algorithms are investigated; both are friends-of-friends schemes with variable linking lengths in the radial and transverse dimenisons. The chief difference between the algorithms is in the redshift linking length. The algorithm proposed by Huchra & Geller (1982) uses a generous linking length designed to find 'fingers of god,' while that of Nolthenius & White (1987) uses a smaller linking length to minimize contamination by projection. We find that neither of the algorithms studied is intrinsically superior to the other; rather, the ideal algorithm as well as the ideal algorithm parameters depends on the purpose for which groups are to be studied. The Huchra & Geller algorithm misses few real groups, at the cost of including some spurious groups and members, while the Nolthenius & White algorithm misses high velocity dispersion groups and members but is less likely to include interlopers in its group assignments. Adjusting the parameters of either algorithm results in a trade-off between group accuracy and completeness. In a companion paper we investigate the accuracy of virial mass estimates and clustering properties of groups identified using these algorithms.

Identification of a Linked Set of Genes in Serpulina hyodysenteriae (B204) Predicted To Encode Closely Related 39-Kilodalton Extracytoplasmic Proteins

PubMed Central

Gabe, Jeffrey D.; Dragon, Elizabeth; Chang, Ray-Jen; McCaman, Michael T.

1998-01-01

A tandem pair of nearly identical genes from Serpulina hyodysenteriae (B204) were cloned and sequenced. The full open reading frame of one gene and the partial open reading frame of the neighboring gene appear to encode secreted proteins which are homologous to, yet distinct from, the 39-kDa extracytoplasmic protein purified from the membrane fraction of S. hyodysenteriae. We have designated these newly identified genes vspA and vspB (for variable surface protein). PMID:9440540

The impact of GPX1 on the association of groundwater selenium and depression: a project FRONTIER study

PubMed Central

2013-01-01

Background Prior animal model and human-based studies have linked selenium concentrations to decreased risk for depression; however, this work has not focused on household groundwater levels or specific depressive symptoms. The current study evaluated the link between groundwater selenium levels and depression. We also sought to determine if a functional polymorphism in the glutathione peroxidase 1 (GPX1) gene impacted this link. Methods We used a cross-sectional design to analyze data from 585 participants (183 men and 402 women) from Project FRONTIER, a study of rural health in West Texas. Residential selenium concentrations were estimated using Geospatial Information System (GIS) analyses. Linear regression models were created using Geriatric Depression Scale (GDS-30) total and subfactor scores as outcome variables and selenium concentrations as predictor variables. Analyses were re-run after stratification of the sample on GPX1 Pro198Leu genotype (rs1050454). Results Selenium levels were significantly and negatively related to all GDS and subfactor scores accounting for up to 17% of the variance beyond covariates. Selenium was most strongly protective against depression among homozygous carriers of the C allele at the Pro198Leu polymorphism of the GPX1 gene. Analyses also point towards a gene-environmental interaction between selenium exposure and GPX1 polymorphism. Conclusion Our results support the link between groundwater selenium levels and decreased depression symptoms. These findings also highlight the need to consider the genetics of the glutathione peroxidase system when examining this relationship, as variation in the GPX1 gene is related to depression risk and significantly influences the protective impact of selenium, which is indicative of a gene-environment interaction. PMID:23289525

Design and optimization of a fiber optic data link for new generation on-board SAR processing architectures

NASA Astrophysics Data System (ADS)

Ciminelli, Caterina; Dell'Olio, Francesco; Armenise, Mario N.; Iacomacci, Francesco; Pasquali, Franca; Formaro, Roberto

2017-11-01

A fiber optic digital link for on-board data handling is modeled, designed and optimized in this paper. Design requirements and constraints relevant to the link, which is in the frame of novel on-board processing architectures, are discussed. Two possible link configurations are investigated, showing their advantages and disadvantages. An accurate mathematical model of each link component and the entire system is reported and results of link simulation based on those models are presented. Finally, some details on the optimized design are provided.

SMOS reveals the signature of Indian Ocean Dipole events

NASA Astrophysics Data System (ADS)

Durand, Fabien; Alory, Gaël; Dussin, Raphaël; Reul, Nicolas

2013-12-01

The tropical Indian Ocean experiences an interannual mode of climatic variability, known as the Indian Ocean Dipole (IOD). The signature of this variability in ocean salinity is hypothesized based on modeling and assimilation studies, on account of scanty observations. Soil Moisture and Ocean Salinity (SMOS) satellite has been designed to take up the challenge of sea surface salinity remote sensing. We show that SMOS data can be used to infer the pattern of salinity variability linked with the IOD events. The core of maximum variability is located in the central tropical basin, south of the equator. This region is anomalously salty during the 2010 negative IOD event, and anomalously fresh during the 2011 positive IOD event. The peak-to-peak anomaly exceeds one salinity unit, between late 2010 and late 2011. In conjunction with other observational datasets, SMOS data allow us to draw the salt budget of the area. It turns out that the horizontal advection is the main driver of salinity anomalies. This finding is confirmed by the analysis of the outputs of a numerical model. This study shows that the advent of SMOS makes it feasible the quantitative assessment of the mechanisms of ocean surface salinity variability in the tropical basins, at interannual timescales.

Reinventing The Design Process: Teams and Models

NASA Technical Reports Server (NTRS)

Wall, Stephen D.

1999-01-01

The future of space mission designing will be dramatically different from the past. Formerly, performance-driven paradigms emphasized data return with cost and schedule being secondary issues. Now and in the future, costs are capped and schedules fixed-these two variables must be treated as independent in the design process. Accordingly, JPL has redesigned its design process. At the conceptual level, design times have been reduced by properly defining the required design depth, improving the linkages between tools, and managing team dynamics. In implementation-phase design, system requirements will be held in crosscutting models, linked to subsystem design tools through a central database that captures the design and supplies needed configuration management and control. Mission goals will then be captured in timelining software that drives the models, testing their capability to execute the goals. Metrics are used to measure and control both processes and to ensure that design parameters converge through the design process within schedule constraints. This methodology manages margins controlled by acceptable risk levels. Thus, teams can evolve risk tolerance (and cost) as they would any engineering parameter. This new approach allows more design freedom for a longer time, which tends to encourage revolutionary and unexpected improvements in design.

Periodic activations of behaviours and emotional adaptation in behaviour-based robotics

NASA Astrophysics Data System (ADS)

Burattini, Ernesto; Rossi, Silvia

2010-09-01

The possible modulatory influence of motivations and emotions is of great interest in designing robotic adaptive systems. In this paper, an attempt is made to connect the concept of periodic behaviour activations to emotional modulation, in order to link the variability of behaviours to the circumstances in which they are activated. The impact of emotion is studied, described as timed controlled structures, on simple but conflicting reactive behaviours. Through this approach it is shown that the introduction of such asynchronies in the robot control system may lead to an adaptation in the emergent behaviour without having an explicit action selection mechanism. The emergent behaviours of a simple robot designed with both a parallel and a hierarchical architecture are evaluated and compared.

Student error patterns as a function of curriculum design: teaching fractions to remedial high school students and high school students with learning disabilities.

PubMed

Kelly, B; Gersten, R; Carnine, D

1990-01-01

This study evaluated the relative effectiveness of a curriculum that incorporated three empirically derived principles of curriculum design with a basal approach in teaching basic fractions concepts to students with learning disabilities and other low performing students in high school remedial math classes. The components of effective mathematics instruction articulated by Good and Grouws (1979) were implemented in both conditions. Thus, the curriculum design variables were isolated by keeping all other aspects of instruction constant. Results indicated that, although both programs were reasonably successful in teaching the material, the curriculum program utilizing sophisticated principles of curriculum design was significantly more effective. Mean scores on a curriculum-referenced test were 96.5% for that group and 82.3% for the basal group. Secondary analyses of item clusters revealed that areas of weakness in the performance of the basal group could be directly linked to hypothesized flaws in its curriculum design.

Multi-objective Optimization of Departure Procedures at Gimpo International Airport

NASA Astrophysics Data System (ADS)

Kim, Junghyun; Lim, Dongwook; Monteiro, Dylan Jonathan; Kirby, Michelle; Mavris, Dimitri

2018-04-01

Most aviation communities have increasing concerns about the environmental impacts, which are directly linked to health issues for local residents near the airport. In this study, the environmental impact of different departure procedures using the Aviation Environmental Design Tool (AEDT) was analyzed. First, actual operational data were compiled at Gimpo International Airport (March 20, 2017) from an open source. Two modifications were made in the AEDT to model the operational circumstances better and the preliminary AEDT simulations were performed according to the acquired operational procedures. Simulated noise results showed good agreements with noise measurement data at specific locations. Second, a multi-objective optimization of departure procedures was performed for the Boeing 737-800. Four design variables were selected and AEDT was linked to a variety of advanced design methods. The results showed that takeoff thrust had the greatest influence and it was found that fuel burn and noise had an inverse relationship. Two points representing each fuel burn and noise optimum on the Pareto front were parsed and run in AEDT to compare with the baseline. The results showed that the noise optimum case reduced Sound Exposure Level 80-dB noise exposure area by approximately 5% while the fuel burn optimum case reduced total fuel burn by 1% relative to the baseline for aircraft-level analysis.

Design, synthesis and characterization of novel binary V(V)-Schiff base materials linked with insulin-mimetic vanadium-induced differentiation of 3T3-L1 fibroblasts to adipocytes. Structure-function correlations at the molecular level.

PubMed

Halevas, E; Tsave, O; Yavropoulou, M P; Hatzidimitriou, A; Yovos, J G; Psycharis, V; Gabriel, C; Salifoglou, A

2015-06-01

Among the various roles of vanadium in the regulation of intracellular signaling, energy metabolism and insulin mimesis, its exogenous activity stands as a contemporary challenge currently under investigation and a goal to pursue as a metallodrug against Diabetes mellitus II. In this regard, the lipogenic activity of vanadium linked to the development of well-defined anti-diabetic vanadodrugs has been investigated through: a) specifically designing and synthesizing Schiff base organic ligands L, bearing a variable number of terminal alcohols, b) a series of well-defined soluble binary V(V)-L compounds synthesized and physicochemically characterized, c) a study of their cytotoxic effect and establishment of adipogenic activity in 3T3-L1 fibroblasts toward mature adipocytes, and d) biomarker examination of a closely-linked molecular target involving or influenced by the specific V(V) forms, cumulatively delineating factors involved in potential pathways linked to V(V)-induced insulin-like activity. Collectively, the results a) project the importance of specific structural features in Schiff ligands bound to V(V), thereby influencing the emergence of its (a)toxicity and for the first time its insulin-like activity in pre-adipocyte differentiation, b) contribute to the discovery of molecular targets influenced by the specific vanadoforms seeking to induce glucose uptake, and c) indicate an interplay of V(V) structural speciation and cell-differentiation biological activity, thereby gaining insight into vanadium's potential as a future metallodrug in Diabetes mellitus. Copyright © 2015 Elsevier Inc. All rights reserved.

[Follow-up of alcohol and/or cocaine dependents after their discharge from a therapeutic community: a pilot study].

PubMed

Lopez-Fernandez, Olatz; Ferrer-Pérez, Xavier; Lafarga-Lebey, Sandra; Honrubia-Serrano, María Luisa; Tudela-Marí, Maite

2011-01-01

In Spain, the Therapeutic Community (TC) constitutes a common model of treatment in the field of addictions, although there hardly exists any investigation about its efficiency and the persistence of its attainments. To evaluate the short, half and long term effects of treatment of addiction to alcohol or cocaine in the TC run by "Fundacion Salud y Comunidad" (Foundation Health and Community). descriptive pilot study, with a sequential design of cohort. 91 users completed a survey specifically designed to know their evolution at different follow-up periods (1, 3, 5 or 10 years after their exit from the TC): socio-demographic, psychoactive substance use, other variables related to the stay at the TC. Changes between before the TC and the present time regarding variables such as academic, labour, drug consumption, health, family and social adaptation and their criminal behaviour are described. the cohorts showed a relatively common previous socio-demographic pattern having received a similar treatment. The users reported to have diminished the frequent consumption of the main drug, having 48.9% never relapsed even through an occasional consumption of the drug/s. Also they perceived to have improved their health and family relations, as well as their aggressive behaviour and legal problems linked with their consumption of drug/s. after their rehabilitation in a TC, the users report a global decrease of the consumption of drugs and perceive an improvement of their health, family relations, violence and other problems linked to their former drug use.

The Effect of Acculturation and Immigration on the Victimization and Psychological Distress Link in a National Sample of Latino Women

ERIC Educational Resources Information Center

Cuevas, Carlos A.; Sabina, Chiara; Bell, Kristin A.

2012-01-01

Distinct bodies of research have examined the link between victimization and psychological distress and cultural variables and psychological health, but little is known about how cultural variables affect psychological distress among Latino victims. Substantial research has concluded that Latino women are more likely than non-Latino women to…

Qubit-Programmable Operations on Quantum Light Fields

PubMed Central

Barbieri, Marco; Spagnolo, Nicolò; Ferreyrol, Franck; Blandino, Rémi; Smith, Brian J.; Tualle-Brouri, Rosa

2015-01-01

Engineering quantum operations is a crucial capability needed for developing quantum technologies and designing new fundamental physics tests. Here we propose a scheme for realising a controlled operation acting on a travelling continuous-variable quantum field, whose functioning is determined by a discrete input qubit. This opens a new avenue for exploiting advantages of both information encoding approaches. Furthermore, this approach allows for the program itself to be in a superposition of operations, and as a result it can be used within a quantum processor, where coherences must be maintained. Our study can find interest not only in general quantum state engineering and information protocols, but also details an interface between different physical platforms. Potential applications can be found in linking optical qubits to optical systems for which coupling is best described in terms of their continuous variables, such as optomechanical devices. PMID:26468614

Understanding Process in Group-Based Intervention Delivery: Social Network Analysis and Intra-entity Variability Methods as Windows into the "Black Box".

PubMed

Molloy Elreda, Lauren; Coatsworth, J Douglas; Gest, Scott D; Ram, Nilam; Bamberger, Katharine

2016-11-01

Although the majority of evidence-based programs are designed for group delivery, group process and its role in participant outcomes have received little empirical attention. Data were collected from 20 groups of participants (94 early adolescents, 120 parents) enrolled in an efficacy trial of a mindfulness-based adaptation of the Strengthening Families Program (MSFP). Following each weekly session, participants reported on their relations to group members. Social network analysis and methods sensitive to intraindividual variability were integrated to examine weekly covariation between group process and participant progress, and to predict post-intervention outcomes from levels and changes in group process. Results demonstrate hypothesized links between network indices of group process and intervention outcomes and highlight the value of this unique analytic approach to studying intervention group process.

Testing relationships from the hierarchical model of intrinsic and extrinsic motivation using flow as a motivational consequence.

PubMed

Kowal, J; Fortier, M S

2000-06-01

The purpose of this study was to test a motivational model based on Vallerand's (1997) Hierarchical Model of Intrinsic and Extrinsic Motivation. This model incorporates situational and contextual motivational variables, and was tested using a time-lagged design. Master's level swimmers (N = 104) completed a questionnaire on two separate occasions. At Time 1, situational social factors (perceptions of success and perceptions of the motivational climate), situational motivational mediators (perceptions of autonomy, competence, and relatedness), situational motivation, and flow were assessed immediately following a swim practice. Contextual measures of these same variables were assessed at Time 2, 1 week later, with the exception of flow. Results of a path analysis supported numerous links in the hypothesized model. Findings are discussed in light of research and theory on motivation and flow.

Design and testing of an advanced implantable neuroprosthesis with myoelectric control.

PubMed

Hart, Ronald L; Bhadra, Niloy; Montague, Fred W; Kilgore, Kevin L; Peckham, P Hunter

2011-02-01

An implantable stimulator-telemeter (IST-12) was developed for applications in neuroprosthetic restoration of limb function in paralyzed individuals. The IST-12 provides 12 stimulation channels and two myoelectric signal (MES) channels. The MES circuitry includes a two-channel multiplexer, preamplifier, variable gain amplifier/bandpass filter, full-wave rectifier, and bin integrator. Power and control signals are transmitted from an external control unit to the IST-12 through an inductive link. Recorded MES signals are telemetered back to the external control unit through the same inductive link. Following bench testing, one device was implanted chronically in a dog for 15 months and evaluated. Conditions were identified in which MES could be recorded with minimal stimulus artifact. The ability to record MES in the presence of stimulation was verified, confirming the potential of the IST-12 to be used as a myoelectric controlled neuroprosthesis.

Epidemics in networks: a master equation approach

NASA Astrophysics Data System (ADS)

Cotacallapa, M.; Hase, M. O.

2016-02-01

A problem closely related to epidemiology, where a subgraph of ‘infected’ links is defined inside a larger network, is investigated. This subgraph is generated from the underlying network by a random variable, which decides whether a link is able to propagate a disease/information. The relaxation timescale of this random variable is examined in both annealed and quenched limits, and the effectiveness of propagation of disease/information is analyzed. The dynamics of the model is governed by a master equation and two types of underlying network are considered: one is scale-free and the other has exponential degree distribution. We have shown that the relaxation timescale of the contagion variable has a major influence on the topology of the subgraph of infected links, which determines the efficiency of spreading of disease/information over the network.

Telecom Link--A Competitive Simulated Design Exercise.

ERIC Educational Resources Information Center

Freeman, J.; Allen, J.

1982-01-01

Telecom link is a structured design exercise concerned with building a telecommunications link between London and Amsterdam. Designed for A-level physics, the simulation requires a minimum of 10 hours. Aims of the exercise, design specifications and technical aspects, and summaries of four possible technologies used in the simulation are…

78 FR 66990 - Additional Designations, Foreign Narcotics Kingpin Designation Act

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-07

...) [SDNTK] (Linked To: ARRENDADORA TURIN, S.A.; Linked To: DESARROLLOS BIO GAS, S.A. DE C.V.; Linked To: ECA...] (Linked To: BLUE POINT SALT, S.A. DE C.V.; Linked To: DESARROLLOS BIO GAS, S.A. DE C.V.; Linked To: ECA ENERGETICOS, S.A. DE C.V.; Linked To: ORGANIC SALT, S.A. DE C.V.; Linked To: PETRO BIO, S. DE R.L. DE C.V...

Design of Broadband High Dynamic-Range Fiber Optic Links

NASA Astrophysics Data System (ADS)

Monsurrò, P.; Tommasino, P.; Trifiletti, A.; Vannucci, A.

2018-04-01

An analytic design-oriented model of microwave optical links has been developed. The core of the model is the non-linear and noise model of a Mach-Zehnder LiNbO3 interferometer. Both a 100 MHz-20 GHz link and a linearized microwave link, comprising an auxiliary modulator, have been designed and prototyped by using the model.

Variable Coding and Modulation Experiment Using NASA's Space Communication and Navigation Testbed

NASA Technical Reports Server (NTRS)

Downey, Joseph A.; Mortensen, Dale J.; Evans, Michael A.; Tollis, Nicholas S.

2016-01-01

National Aeronautics and Space Administration (NASA)'s Space Communication and Navigation Testbed on the International Space Station provides a unique opportunity to evaluate advanced communication techniques in an operational system. The experimental nature of the Testbed allows for rapid demonstrations while using flight hardware in a deployed system within NASA's networks. One example is variable coding and modulation, which is a method to increase data-throughput in a communication link. This paper describes recent flight testing with variable coding and modulation over S-band using a direct-to-earth link between the SCaN Testbed and the Glenn Research Center. The testing leverages the established Digital Video Broadcasting Second Generation (DVB-S2) standard to provide various modulation and coding options. The experiment was conducted in a challenging environment due to the multipath and shadowing caused by the International Space Station structure. Performance of the variable coding and modulation system is evaluated and compared to the capacity of the link, as well as standard NASA waveforms.

Resistance to Change and Preference for Variable versus Fixed Response Sequences

ERIC Educational Resources Information Center

Arantes, Joana; Berg, Mark E.; Le, Dien; Grace, Randolph C.

2012-01-01

In Experiment 1, 4 pigeons were trained on a multiple chain schedule in which the initial link was a variable-interval (VI) 20-s schedule signalled by a red or green center key, and terminal links required four responses made to the left (L) and/or right (R) keys. In the REPEAT component, signalled by red keylights, only LRLR terminal-link…

CNES reliability approach for the qualification of MEMS for space

NASA Astrophysics Data System (ADS)

Pressecq, Francis; Lafontan, Xavier; Perez, Guy; Fortea, Jean-Pierre

2001-10-01

This paper describes the reliability approach performs at CNES to evaluate MEMS for space application. After an introduction and a detailed state of the art on the space requirements and on the use of MEMS for space, different approaches for taking into account MEMS in the qualification phases are presented. CNES proposes improvement to theses approaches in term of failure mechanisms identification. Our approach is based on a design and test phase deeply linked with a technology study. This workflow is illustrated with an example: the case of a variable capacitance processed with MUMPS process is presented.

Do clients' problem-solving appraisals predict career counseling outcomes or vice versa? A reanalysis of Heppner, et al.

PubMed

Lee, Dong-Gwi; Park, Hyun-Joo; Heppner, Mary J

2009-12-01

Using Heppner, et al.'s data from 2004, this study tested career counseling clients in the United States on problem-solving appraisal scores and career-related variables. A cross-lagged panel design with structural equation modeling was used. Results supported the link between clients' precounseling problem-solving appraisal scores and career outcome. This finding held for career decision-making, but not for vocational identity. The study provided further support for Heppner, et al.'s findings, highlighting the influential role of clients' problem-solving appraisals in advancing their career decision-making processes.

Quantifying Disease Progression in Amyotrophic Lateral Sclerosis

PubMed Central

Simon, Neil G; Turner, Martin R; Vucic, Steve; Al-Chalabi, Ammar; Shefner, Jeremy; Lomen-Hoerth, Catherine; Kiernan, Matthew C

2014-01-01

Amyotrophic lateral sclerosis (ALS) exhibits characteristic variability of onset and rate of disease progression, with inherent clinical heterogeneity making disease quantitation difficult. Recent advances in understanding pathogenic mechanisms linked to the development of ALS impose an increasing need to develop strategies to predict and more objectively measure disease progression. This review explores phenotypic and genetic determinants of disease progression in ALS, and examines established and evolving biomarkers that may contribute to robust measurement in longitudinal clinical studies. With targeted neuroprotective strategies on the horizon, developing efficiencies in clinical trial design may facilitate timely entry of novel treatments into the clinic. PMID:25223628

Multimodal information Management: Evaluation of Auditory and Haptic Cues for NextGen Communication Displays

NASA Technical Reports Server (NTRS)

Begault, Durand R.; Bittner, Rachel M.; Anderson, Mark R.

2012-01-01

Auditory communication displays within the NextGen data link system may use multiple synthetic speech messages replacing traditional ATC and company communications. The design of an interface for selecting amongst multiple incoming messages can impact both performance (time to select, audit and release a message) and preference. Two design factors were evaluated: physical pressure-sensitive switches versus flat panel "virtual switches", and the presence or absence of auditory feedback from switch contact. Performance with stimuli using physical switches was 1.2 s faster than virtual switches (2.0 s vs. 3.2 s); auditory feedback provided a 0.54 s performance advantage (2.33 s vs. 2.87 s). There was no interaction between these variables. Preference data were highly correlated with performance.

Exploring the SDSS Dataset with Linked Scatter Plots: I. EMP, CEMP, and CV Stars

NASA Technical Reports Server (NTRS)

Carbon, Duane F.; Henze, Christopher; Nelson, Bron C.

2017-01-01

We present the results of a search for EMP, CEMP, and cataclysmic variable stars using a new exploration tool based on linked scatter plots (LSPs). Our approach is especially designed to work with very large spectrum data sets such as the SDSS, LAMOST, RAVE, and Gaia data sets and can be applied to stellar, galaxy, and quasar spectra. As a demonstration, we conduct a search for EMP, CEMP, and cataclysmic variable stars in the SDSS DR10 data set. We first created a 3326-dimensional phase space containing nearly 2 billion measures of the strengths of over 1600 spectral features in 569,738 SDSS stars. These measures capture essentially all the stellar atomic and molecular species visible at the resolution of SDSS spectra. We show how LSPs can be used to quickly isolate and examine interesting portions of this phase space. To illustrate, we use LSPs coupled with cuts in selected portions of phase space to extract EMP stars, C-rich EMP stars, and CV stars. We present identifications for 59 previously unrecognized candidate EMP stars and 11 previously unrecognized candidate CEMP stars. We also call attention to 2 candidate He II emission CV stars found by the LSP approach that have not yet been discussed in the literature.

Genetic architecture of threshold reaction norms for male alternative reproductive tactics in Atlantic salmon (Salmo salar L.)

PubMed Central

Lepais, Olivier; Manicki, Aurélie; Glise, Stéphane; Buoro, Mathieu; Bardonnet, Agnès

2017-01-01

Alternative mating tactics have important ecological and evolutionary implications and are determined by complex interactions between environmental and genetic factors. Here, we study the genetic effect and architecture of the variability in reproductive tactics among Atlantic salmon males which can either mature sexually early in life in freshwater or more commonly only after completing a migration at sea. We applied the latent environmental threshold model (LETM), which provides a conceptual framework linking individual status to a threshold controlling the decision to develop alternative traits, in an innovative experimental design using a semi-natural river which allowed for ecologically relevant phenotypic expression. Early male parr maturation rates varied greatly across families (10 to 93%) which translated into 90% [64–100%] of the phenotypic variation explained by genetic variation. Three significant QTLs were found for the maturation status, however only one collocated with a highly significant QTL explaining 20.6% of the variability of the maturation threshold located on chromosome 25 and encompassing a locus previously shown to be linked to sea age at maturity in anadromous Atlantic salmon. These results provide new empirical illustration of the relevance of the LETM for a better understanding of alternative mating tactics evolution in natural populations. PMID:28281522

Exploring the SDSS Dataset with Linked Scatter Plots: I. EMP, CEMP, and CV Stars.

PubMed

Carbon, Duane F; Henze, Christopher; Nelson, Bron C

2017-02-01

We present the results of a search for EMP, CEMP, and cataclysmic variable stars using a new exploration tool based on linked scatter plots (LSPs). Our approach is especially designed to work with very large spectrum data sets such as the SDSS, LAMOST, RAVE, and Gaia data sets and can be applied to stellar, galaxy, and quasar spectra. As a demonstration, we conduct a search for EMP, CEMP, and cataclysmic variable stars in the SDSS DR10 data set. We first created a 3326-dimensional phase space containing nearly 2 billion measures of the strengths of over 1600 spectral features in 569,738 SDSS stars. These measures capture essentially all the stellar atomic and molecular species visible at the resolution of SDSS spectra. We show how LSPs can be used to quickly isolate and examine interesting portions of this phase space. To illustrate, we use LSPs coupled with cuts in selected portions of phase space to extract EMP stars, C-rich EMP stars, and CV stars. We present identifications for 59 previously unrecognized candidate EMP stars and 11 previously unrecognized candidate CEMP stars. We also call attention to 2 candidate He II emission CV stars found by the LSP approach that have not yet been discussed in the literature.

Management matters: the link between hospital organisation and quality of patient care

PubMed Central

West, E.

2001-01-01

Some hospital trusts and health authorities consistently outperform others on different dimensions of performance. Why? There is some evidence that "management matters", as well as the combined efforts of individual clinicians and teams. However, studies that have been conducted on the link between the organisation and management of services and quality of patient care can be criticised both theoretically and methodologically. A larger, and arguably more rigorous, body of work exists on the performance of firms in the private sector, often conducted within the disciplines of organisational behaviour or human resource management. Studies in these traditions have focused on the effects of decentralisation, participation, innovative work practices, and "complementarities" on outcome variables such as job satisfaction and performance. The aim of this paper is to identify a number of reviews and research traditions that might bring new ideas into future work on the determinants of hospital performance. Ideally, future research should be more theoretically informed and should use longitudinal rather than cross sectional research designs. The use of statistical methods such as multilevel modelling, which allow for the inclusion of variables at different levels of analysis, would enable estimation of the separate contribution that structure and process make to hospital outcomes. Key Words: hospital organisation; hospital performance; management; quality of care PMID:11239143

Exploring the SDSS Dataset with Linked Scatter Plots: I. EMP, CEMP, and CV Stars

PubMed Central

Carbon, Duane F.; Henze, Christopher; Nelson, Bron C.

2017-01-01

We present the results of a search for EMP, CEMP, and cataclysmic variable stars using a new exploration tool based on linked scatter plots (LSPs). Our approach is especially designed to work with very large spectrum data sets such as the SDSS, LAMOST, RAVE, and Gaia data sets and can be applied to stellar, galaxy, and quasar spectra. As a demonstration, we conduct a search for EMP, CEMP, and cataclysmic variable stars in the SDSS DR10 data set. We first created a 3326-dimensional phase space containing nearly 2 billion measures of the strengths of over 1600 spectral features in 569,738 SDSS stars. These measures capture essentially all the stellar atomic and molecular species visible at the resolution of SDSS spectra. We show how LSPs can be used to quickly isolate and examine interesting portions of this phase space. To illustrate, we use LSPs coupled with cuts in selected portions of phase space to extract EMP stars, C-rich EMP stars, and CV stars. We present identifications for 59 previously unrecognized candidate EMP stars and 11 previously unrecognized candidate CEMP stars. We also call attention to 2 candidate He II emission CV stars found by the LSP approach that have not yet been discussed in the literature. PMID:28684884

Spectrum of X-linked hydrocephalus (HSAS), MASA syndrome, and complicated spastic paraplegia (SPG1): Clincal review with six additional families

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schrander-Stumpel, C.; Hoeweler, C.; Jones, M.

X-linked hydrocephalus (HSAS) (MIM{sup *}307000), MASA syndrome (MIM {sup *}303350), and complicated spastic paraplegia (SPG1) (MIM {sup *}3129000) are closely related. Soon after delineation, SPG1 was incorporated into the spectrum of MASA syndrome. HSAS and MASA syndrome show great clinical overlap; DNA linkage analysis places the loci at Xq28. In an increasing number of families with MASA syndrome or HSAS, mutations in L1CAM, a gene located at Xq28, have been reported. In order to further delineate the clinical spectrum, we studied 6 families with male patients presenting with MASA syndrome, HSAS, or a mixed phenotype. We summarized data from previousmore » reports and compared them with our data. Clinical variability appears to be great, even within families. Problems in genetic counseling and prenatal diagnosis, the possible overlap with X-linked corpus callosum agenesis and FG syndrome, and the different forms of X-linked complicated spastic paraplegia are discussed. Since adducted thumbs and spastic paraplegia are found in 90% of the patients, the condition may be present in males with nonspecific mental retardation. We propose to abandon the designation MASA syndrome and use the term HSAS/MASA spectrum, incorporating SPG1. 79 refs., 6 figs., 2 tabs.« less

Land Use Change on Household Farms in the Ecuadorian Amazon: Design and Implementation of an Agent-Based Model.

PubMed

Mena, Carlos F; Walsh, Stephen J; Frizzelle, Brian G; Xiaozheng, Yao; Malanson, George P

2011-01-01

This paper describes the design and implementation of an Agent-Based Model (ABM) used to simulate land use change on household farms in the Northern Ecuadorian Amazon (NEA). The ABM simulates decision-making processes at the household level that is examined through a longitudinal, socio-economic and demographic survey that was conducted in 1990 and 1999. Geographic Information Systems (GIS) are used to establish spatial relationships between farms and their environment, while classified Landsat Thematic Mapper (TM) imagery is used to set initial land use/land cover conditions for the spatial simulation, assess from-to land use/land cover change patterns, and describe trajectories of land use change at the farm and landscape levels. Results from prior studies in the NEA provide insights into the key social and ecological variables, describe human behavioral functions, and examine population-environment interactions that are linked to deforestation and agricultural extensification, population migration, and demographic change. Within the architecture of the model, agents are classified as active or passive. The model comprises four modules, i.e., initialization, demography, agriculture, and migration that operate individually, but are linked through key household processes. The main outputs of the model include a spatially-explicit representation of the land use/land cover on survey and non-survey farms and at the landscape level for each annual time-step, as well as simulated socio-economic and demographic characteristics of households and communities. The work describes the design and implementation of the model and how population-environment interactions can be addressed in a frontier setting. The paper contributes to land change science by examining important pattern-process relations, advocating a spatial modeling approach that is capable of synthesizing fundamental relationships at the farm level, and links people and environment in complex ways.

Impulsivity and suicidality: the mediating role of painful and provocative experiences.

PubMed

Bender, Theodore W; Gordon, Kathryn H; Bresin, Konrad; Joiner, Thomas E

2011-03-01

Multiple studies have reported a link between high levels of impulsivity and suicidal behavior. Joiner's (2005) explanation for this link is that impulsive individuals have a greater tendency to experience painful and provocative events that habituate them to fear and pain, which leads to an acquired capability for engaging in suicidal behavior. Study 1 tested Joiner's (2005) hypothesis in a sample of 182 undergraduate students who completed self-report questionnaires on impulsivity, frequency of painful and provocative events, and acquired capability for suicide. In addition to self-report, pain tolerance (an aspect of acquired capability for suicide) was measured with a pressure algometer. Study 2 sought to replicate our findings from Study 1 in a sample of 516 clinical outpatients using a multi-faceted measure of impulsivity. Consistent with prediction, product of coefficients tests for mediation (MacKinnon et al., 2002) revealed that impulsivity has an indirect relationship with acquired capability for suicidal behavior, and that this relationship is mediated by painful and provocative events. Data from our studies are cross-sectional in nature, which does not allow for conclusions about the temporal ordering of our variables. In addition, self-report was used to measure most variables. Future research may benefit from a longitudinal design and the inclusion of other modes of assessment (e.g., behavioral measures of impulsivity). Our findings suggest that the link between impulsivity and suicidal behavior occurs because impulsive people tend to have a greater capability for suicidal behavior, which they have acquired through experiencing painful and provocative events. Copyright © 2010 Elsevier B.V. All rights reserved.

The influence of simulator input conditions on the wear of total knee replacements: An experimental and computational study

PubMed Central

Brockett, Claire L; Abdelgaied, Abdellatif; Haythornthwaite, Tony; Hardaker, Catherine; Fisher, John; Jennings, Louise M

2016-01-01

Advancements in knee replacement design, material and sterilisation processes have provided improved clinical results. However, surface wear of the polyethylene leading to osteolysis is still considered the longer-term risk factor. Experimental wear simulation is an established method for evaluating the wear performance of total joint replacements. The aim of this study was to investigate the influence of simulation input conditions, specifically input kinematic magnitudes, waveforms and directions of motion and position of the femoral centre of rotation, on the wear performance of a fixed-bearing total knee replacement through a combined experimental and computational approach. Studies were completed using conventional and moderately cross-linked polyethylene to determine whether the influence of these simulation input conditions varied with material. The position of the femoral centre of rotation and the input kinematics were shown to have a significant influence on the wear rates. Similar trends were shown for both the conventional and moderately cross-linked polyethylene materials, although lower wear rates were found for the moderately cross-linked polyethylene due to the higher level of cross-linking. The most important factor influencing the wear was the position of the relative contact point at the femoral component and tibial insert interface. This was dependent on the combination of input displacement magnitudes, waveforms, direction of motion and femoral centre of rotation. This study provides further evidence that in order to study variables such as design and material in total knee replacement, it is important to carefully control knee simulation conditions. This can be more effectively achieved through the use of displacement control simulation. PMID:27160561

The amplitude of decadal to multidecadal variability in precipitation simulated by state-of-the-art climate models

NASA Astrophysics Data System (ADS)

Ault, T. R.; Cole, J. E.; St. George, S.

2012-11-01

We assess the magnitude of decadal to multidecadal (D2M) variability in Climate Model Intercomparison Project 5 (CMIP5) simulations that will be used to understand, and plan for, climate change as part of the Intergovernmental Panel on Climate Change's 5th Assessment Report. Model performance on D2M timescales is evaluated using metrics designed to characterize the relative and absolute magnitude of variability at these frequencies. In observational data, we find that between 10% and 35% of the total variance occurs on D2M timescales. Regions characterized by the high end of this range include Africa, Australia, western North America, and the Amazon region of South America. In these areas D2M fluctuations are especially prominent and linked to prolonged drought. D2M fluctuations account for considerably less of the total variance (between 5% and 15%) in the CMIP5 archive of historical (1850-2005) simulations. The discrepancy between observation and model based estimates of D2M prominence reflects two features of the CMIP5 archive. First, interannual components of variability are generally too energetic. Second, decadal components are too weak in several key regions. Our findings imply that projections of the future lack sufficient decadal variability, presenting a limited view of prolonged drought and pluvial risk.

Age-related Multiscale Changes in Brain Signal Variability in Pre-task versus Post-task Resting-state EEG.

PubMed

Wang, Hongye; McIntosh, Anthony R; Kovacevic, Natasa; Karachalios, Maria; Protzner, Andrea B

2016-07-01

Recent empirical work suggests that, during healthy aging, the variability of network dynamics changes during task performance. Such variability appears to reflect the spontaneous formation and dissolution of different functional networks. We sought to extend these observations into resting-state dynamics. We recorded EEG in young, middle-aged, and older adults during a "rest-task-rest" design and investigated if aging modifies the interaction between resting-state activity and external stimulus-induced activity. Using multiscale entropy as our measure of variability, we found that, with increasing age, resting-state dynamics shifts from distributed to more local neural processing, especially at posterior sources. In the young group, resting-state dynamics also changed from pre- to post-task, where fine-scale entropy increased in task-positive regions and coarse-scale entropy increased in the posterior cingulate, a key region associated with the default mode network. Lastly, pre- and post-task resting-state dynamics were linked to performance on the intervening task for all age groups, but this relationship became weaker with increasing age. Our results suggest that age-related changes in resting-state dynamics occur across different spatial and temporal scales and have consequences for information processing capacity.

Study of a Car Body Tilting System Using a Variable Link Mechanism: Fundamental Characteristics of Pendulum Motion and Strategy for Perfect Tilting

NASA Astrophysics Data System (ADS)

Yoshida, Hidehisa; Nagai, Masao

This paper analyzes the fundamental dynamic characteristics of a tilting railway vehicle using a variable link mechanism for compensating both the lateral acceleration experienced by passengers and the wheel load imbalance between the inner and outer rails. The geometric relations between the center of rotation, the center of gravity, and the positions of all four links of the tilting system are analyzed. Then, equations of the pendulum motions of the railway vehicle body with a four-link mechanism are derived. A theoretically discussion is given on the geometrical shapes employed in the link mechanism that can simultaneously provide zero lateral acceleration and zero wheel load fluctuation. Then, the perfect tilting condition, which is the control target of the feedforward tilting control, is derived from the linear equation of tilting motion.

Production and characterization of a single-chain variable fragment linked alkaline phosphatase fusion protein for detection of O,O-diethyl organophosphorus pesticides in a one-step enzyme-linked immunosorbent assay

USDA-ARS?s Scientific Manuscript database

A single-chain variable fragment (scFv) and alkaline phosphatase (AP) fusion protein for detection of O, O-diethyl organophosphorus pesticides (OPs) was produced and characterized. The scFv gene was prepared by cloning VL and VH genes from a hybridoma cell secreting monoclonal antibody with broad-s...

A note on deep space optical communication link parameters

NASA Technical Reports Server (NTRS)

Dolinar, S. J.; Yuen, J. H.

1982-01-01

Topical communication in the context of a deep space communication link. Communication link analysis at the optical frequencies differs significantly from that at microwave frequencies such as the traditional S and X-bands used in deep space applications, due to the different technology of transmitter, antenna, modulators, and receivers. In addition, the important role of quantum noise in limiting system performance is quite different than that of thermal noise. The optical link design is put in a design control table format similar to a microwave telecom link design. Key considerations unique to the optical link are discussed.

Development and validation of a building design waste reduction model.

PubMed

Llatas, C; Osmani, M

2016-10-01

Reduction in construction waste is a pressing need in many countries. The design of building elements is considered a pivotal process to achieve waste reduction at source, which enables an informed prediction of their wastage reduction levels. However the lack of quantitative methods linking design strategies to waste reduction hinders designing out waste practice in building projects. Therefore, this paper addresses this knowledge gap through the design and validation of a Building Design Waste Reduction Strategies (Waste ReSt) model that aims to investigate the relationships between design variables and their impact on onsite waste reduction. The Waste ReSt model was validated in a real-world case study involving 20 residential buildings in Spain. The validation process comprises three stages. Firstly, design waste causes were analyzed. Secondly, design strategies were applied leading to several alternative low waste building elements. Finally, their potential source reduction levels were quantified and discussed within the context of the literature. The Waste ReSt model could serve as an instrumental tool to simulate designing out strategies in building projects. The knowledge provided by the model could help project stakeholders to better understand the correlation between the design process and waste sources and subsequently implement design practices for low-waste buildings. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Web-Based Intervention to Reduce Indoor Tanning Motivations In Adolescents: A Randomized Controlled Trial

PubMed Central

Hillhouse, Joel; Turrisi, Rob; Scaglione, Nichole M.; Cleveland, Michael J.; Baker, Katie; Florence, L. Carter

2016-01-01

Youthful indoor tanning as few as ten sessions can increase the risk of melanoma by 2 to 4 times with each additional session adding another 2% to the risk. Recent research estimates that indoor tanning can be linked to approximately 450,000 cases of skin cancer annually in the United States, Europe, and Australia. Despite these risks, indoor tanning remains popular with adolescents. This study tested the efficacy of a web-based skin cancer prevention intervention designed to reduce indoor tanning motivations in adolescent females. A nationally representative sample of 443 female teens were enrolled from an online panel into a two-arm, parallel group design, randomized controlled trial. Treatment participants received an appearance-focused intervention grounded in established health behavior change models. Controls viewed a teen alcohol prevention website. Outcome variables included willingness and intentions to indoor tan, willingness to sunless tan and measures of indoor tanning attitudes and beliefs. The intervention decreased willingness and intentions to indoor tan and increased sunless tanning willingness relative to controls. We also examined indirect mechanisms of change through intervening variables (e.g., indoor tanning attitudes, norms, positive and negative expectancies) using the product of coefficients approach. The web-based intervention demonstrated efficacy in changing adolescent indoor tanning motivations and improving their orientation toward healthier alternatives. Results from the intervening variable analyses give guidance to future adolescent skin cancer prevention interventions. PMID:27549602

A Web-Based Intervention to Reduce Indoor Tanning Motivations in Adolescents: a Randomized Controlled Trial.

PubMed

Hillhouse, Joel; Turrisi, Rob; Scaglione, Nichole M; Cleveland, Michael J; Baker, Katie; Florence, L Carter

2017-02-01

Youthful indoor tanning as few as ten sessions can increase the risk of melanoma by two to four times with each additional session adding another 2 % to the risk. Recent research estimates that indoor tanning can be linked to approximately 450,000 cases of skin cancer annually in the USA, Europe, and Australia. Despite these risks, indoor tanning remains popular with adolescents. This study tested the efficacy of a web-based skin cancer prevention intervention designed to reduce indoor tanning motivations in adolescent females. A nationally representative sample of 443 female teens was enrolled from an online panel into a two-arm, parallel group design, randomized controlled trial. Treatment participants received an appearance-focused intervention grounded in established health behavior change models. Controls viewed a teen alcohol prevention website. Outcome variables included willingness and intentions to indoor tan, willingness to sunless tan, and measures of indoor tanning attitudes and beliefs. The intervention decreased willingness and intentions to indoor tan and increased sunless tanning willingness relative to controls. We also examined indirect mechanisms of change through intervening variables (e.g., indoor tanning attitudes, norms, positive and negative expectancies) using the product of coefficient approach. The web-based intervention demonstrated efficacy in changing adolescent indoor tanning motivations and improving their orientation toward healthier alternatives. Results from the intervening variable analyses give guidance to future adolescent skin cancer prevention interventions.

TNF-α levels in cancer patients relate to social variables

PubMed Central

Marucha, Phillip T.; Crespin, Timothy R.; Shelby, Rebecca A.; Andersen, Barbara L.

2008-01-01

Tumor necrosis factor-α (TNF-α) is an important cytokine associated with tumor regression and increased survival time for cancer patients. Research evidence relates immune factors (e.g., natural killer (NK) cell counts, NK cell lysis, lymphocyte profile, and lymphocyte proliferation) to the frequency and quality of social relations among cancer patients. We hypothesized that disruptions in social relations would be associated with lower TNF-α responses, and conversely, that reports of positive changes in social relations correlate with stronger responses. A prospective design measured changes in social activity and relationship satisfaction with a partner in 44 breast cancer patients at the time of cancer diagnosis, and initial surgery and 12 months later. Results indicated that patients reporting increased social activities or satisfaction exhibited stronger stimulated TNF-α responses. This is the first study to link changes in patient social relations with a cancer-relevant immune variable. PMID:15890493

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Richen; Guo, Hanqi; Yuan, Xiaoru

Most of the existing approaches to visualize vector field ensembles are to reveal the uncertainty of individual variables, for example, statistics, variability, etc. However, a user-defined derived feature like vortex or air mass is also quite significant, since they make more sense to domain scientists. In this paper, we present a new framework to extract user-defined derived features from different simulation runs. Specially, we use a detail-to-overview searching scheme to help extract vortex with a user-defined shape. We further compute the geometry information including the size, the geo-spatial location of the extracted vortexes. We also design some linked views tomore » compare them between different runs. At last, the temporal information such as the occurrence time of the feature is further estimated and compared. Results show that our method is capable of extracting the features across different runs and comparing them spatially and temporally.« less

Reply to comment by Fred L. Ogden et al. on "Beyond the SCS-CN method: A theoretical framework for spatially lumped rainfall-runoff response"

NASA Astrophysics Data System (ADS)

Bartlett, M. S.; Parolari, A. J.; McDonnell, J. J.; Porporato, A.

2017-07-01

Though Ogden et al. list several shortcomings of the original SCS-CN method, fit for purpose is a key consideration in hydrological modelling, as shown by the adoption of SCS-CN method in many design standards. The theoretical framework of Bartlett et al. [2016a] reveals a family of semidistributed models, of which the SCS-CN method is just one member. Other members include event-based versions of the Variable Infiltration Capacity (VIC) model and TOPMODEL. This general model allows us to move beyond the limitations of the original SCS-CN method under different rainfall-runoff mechanisms and distributions for soil and rainfall variability. Future research should link this general model approach to different hydrogeographic settings, in line with the call for action proposed by Ogden et al.

New approaches to optimization in aerospace conceptual design

NASA Technical Reports Server (NTRS)

Gage, Peter J.

1995-01-01

Aerospace design can be viewed as an optimization process, but conceptual studies are rarely performed using formal search algorithms. Three issues that restrict the success of automatic search are identified in this work. New approaches are introduced to address the integration of analyses and optimizers, to avoid the need for accurate gradient information and a smooth search space (required for calculus-based optimization), and to remove the restrictions imposed by fixed complexity problem formulations. (1) Optimization should be performed in a flexible environment. A quasi-procedural architecture is used to conveniently link analysis modules and automatically coordinate their execution. It efficiently controls a large-scale design tasks. (2) Genetic algorithms provide a search method for discontinuous or noisy domains. The utility of genetic optimization is demonstrated here, but parameter encodings and constraint-handling schemes must be carefully chosen to avoid premature convergence to suboptimal designs. The relationship between genetic and calculus-based methods is explored. (3) A variable-complexity genetic algorithm is created to permit flexible parameterization, so that the level of description can change during optimization. This new optimizer automatically discovers novel designs in structural and aerodynamic tasks.

Independence of Terminal-Link Entry Rate and Immediacy in Concurrent Chains

ERIC Educational Resources Information Center

Berg, Mark E.; Grace, Randolph C.

2004-01-01

In Phase 1, 4 pigeons were trained on a three-component multiple concurrent-chains procedure in which components differed only in terms of relative terminal-link entry rate. The terminal links were variable-interval schedules and were varied across four conditions to produce immediacy ratios of 4:1, 1:4, 2:1, and 1:2. Relative terminal-link entry…

Linking 1D coastal ocean modelling to environmental management: an ensemble approach

NASA Astrophysics Data System (ADS)

Mussap, Giulia; Zavatarelli, Marco; Pinardi, Nadia

2017-12-01

The use of a one-dimensional interdisciplinary numerical model of the coastal ocean as a tool contributing to the formulation of ecosystem-based management (EBM) is explored. The focus is on the definition of an experimental design based on ensemble simulations, integrating variability linked to scenarios (characterised by changes in the system forcing) and to the concurrent variation of selected, and poorly constrained, model parameters. The modelling system used was previously specifically designed for the use in "data-rich" areas, so that horizontal dynamics can be resolved by a diagnostic approach and external inputs can be parameterised by nudging schemes properly calibrated. Ensembles determined by changes in the simulated environmental (physical and biogeochemical) dynamics, under joint forcing and parameterisation variations, highlight the uncertainties associated to the application of specific scenarios that are relevant to EBM, providing an assessment of the reliability of the predicted changes. The work has been carried out by implementing the coupled modelling system BFM-POM1D in an area of Gulf of Trieste (northern Adriatic Sea), considered homogeneous from the point of view of hydrological properties, and forcing it by changing climatic (warming) and anthropogenic (reduction of the land-based nutrient input) pressure. Model parameters affected by considerable uncertainties (due to the lack of relevant observations) were varied jointly with the scenarios of change. The resulting large set of ensemble simulations provided a general estimation of the model uncertainties related to the joint variation of pressures and model parameters. The information of the model result variability aimed at conveying efficiently and comprehensibly the information on the uncertainties/reliability of the model results to non-technical EBM planners and stakeholders, in order to have the model-based information effectively contributing to EBM.

Network-based regularization for matched case-control analysis of high-dimensional DNA methylation data.

PubMed

Sun, Hokeun; Wang, Shuang

2013-05-30

The matched case-control designs are commonly used to control for potential confounding factors in genetic epidemiology studies especially epigenetic studies with DNA methylation. Compared with unmatched case-control studies with high-dimensional genomic or epigenetic data, there have been few variable selection methods for matched sets. In an earlier paper, we proposed the penalized logistic regression model for the analysis of unmatched DNA methylation data using a network-based penalty. However, for popularly applied matched designs in epigenetic studies that compare DNA methylation between tumor and adjacent non-tumor tissues or between pre-treatment and post-treatment conditions, applying ordinary logistic regression ignoring matching is known to bring serious bias in estimation. In this paper, we developed a penalized conditional logistic model using the network-based penalty that encourages a grouping effect of (1) linked Cytosine-phosphate-Guanine (CpG) sites within a gene or (2) linked genes within a genetic pathway for analysis of matched DNA methylation data. In our simulation studies, we demonstrated the superiority of using conditional logistic model over unconditional logistic model in high-dimensional variable selection problems for matched case-control data. We further investigated the benefits of utilizing biological group or graph information for matched case-control data. We applied the proposed method to a genome-wide DNA methylation study on hepatocellular carcinoma (HCC) where we investigated the DNA methylation levels of tumor and adjacent non-tumor tissues from HCC patients by using the Illumina Infinium HumanMethylation27 Beadchip. Several new CpG sites and genes known to be related to HCC were identified but were missed by the standard method in the original paper. Copyright © 2012 John Wiley & Sons, Ltd.

Difference infiltrometer: a method to measure temporally variable infiltration rates during rainstorms

USGS Publications Warehouse

Moody, John A.; Ebel, Brian A.

2012-01-01

We developed a difference infiltrometer to measure time series of non-steady infiltration rates during rainstorms at the point scale. The infiltrometer uses two, tipping bucket rain gages. One gage measures rainfall onto, and the other measures runoff from, a small circular plot about 0.5-m in diameter. The small size allows the infiltration rate to be computed as the difference of the cumulative rainfall and cumulative runoff without having to route water through a large plot. Difference infiltrometers were deployed in an area burned by the 2010 Fourmile Canyon Fire near Boulder, Colorado, USA, and data were collected during the summer of 2011. The difference infiltrometer demonstrated the capability to capture different magnitudes of infiltration rates and temporal variability associated with convective (high intensity, short duration) and cyclonic (low intensity, long duration) rainstorms. Data from the difference infiltrometer were used to estimate saturated hydraulic conductivity of soil affected by the heat from a wildfire. The difference infiltrometer is portable and can be deployed in rugged, steep terrain and does not require the transport of water, as many rainfall simulators require, because it uses natural rainfall. It can be used to assess infiltration models, determine runoff coefficients, identify rainfall depth or rainfall intensity thresholds to initiate runoff, estimate parameters for infiltration models, and compare remediation treatments on disturbed landscapes. The difference infiltrometer can be linked with other types of soil monitoring equipment in long-term studies for detecting temporal and spatial variability at multiple time scales and in nested designs where it can be linked to hillslope and basin-scale runoff responses.

Systematic review of current efforts to quantify the impacts of climate change on undernutrition.

PubMed

Phalkey, Revati K; Aranda-Jan, Clara; Marx, Sabrina; Höfle, Bernhard; Sauerborn, Rainer

2015-08-18

Malnutrition is a challenge to the health and productivity of populations and is viewed as one of the five largest adverse health impacts of climate change. Nonetheless, systematic evidence quantifying these impacts is currently limited. Our aim was to assess the scientific evidence base for the impact of climate change on childhood undernutrition (particularly stunting) in subsistence farmers in low- and middle-income countries. A systematic review was conducted to identify peer-reviewed and gray full-text documents in English with no limits for year of publication or study design. Fifteen manuscripts were reviewed. Few studies use primary data to investigate the proportion of stunting that can be attributed to climate/weather variability. Although scattered and limited, current evidence suggests a significant but variable link between weather variables, e.g., rainfall, extreme weather events (floods/droughts), seasonality, and temperature, and childhood stunting at the household level (12 of 15 studies, 80%). In addition, we note that agricultural, socioeconomic, and demographic factors at the household and individual levels also play substantial roles in mediating the nutritional impacts. Comparable interdisciplinary studies based on primary data at a household level are urgently required to guide effective adaptation, particularly for rural subsistence farmers. Systemization of data collection at the global level is indispensable and urgent. We need to assimilate data from long-term, high-quality agricultural, environmental, socioeconomic, health, and demographic surveillance systems and develop robust statistical methods to establish and validate causal links, quantify impacts, and make reliable predictions that can guide evidence-based health interventions in the future.

Systematic review of current efforts to quantify the impacts of climate change on undernutrition

PubMed Central

Phalkey, Revati K.; Aranda-Jan, Clara; Marx, Sabrina; Höfle, Bernhard; Sauerborn, Rainer

2015-01-01

Malnutrition is a challenge to the health and productivity of populations and is viewed as one of the five largest adverse health impacts of climate change. Nonetheless, systematic evidence quantifying these impacts is currently limited. Our aim was to assess the scientific evidence base for the impact of climate change on childhood undernutrition (particularly stunting) in subsistence farmers in low- and middle-income countries. A systematic review was conducted to identify peer-reviewed and gray full-text documents in English with no limits for year of publication or study design. Fifteen manuscripts were reviewed. Few studies use primary data to investigate the proportion of stunting that can be attributed to climate/weather variability. Although scattered and limited, current evidence suggests a significant but variable link between weather variables, e.g., rainfall, extreme weather events (floods/droughts), seasonality, and temperature, and childhood stunting at the household level (12 of 15 studies, 80%). In addition, we note that agricultural, socioeconomic, and demographic factors at the household and individual levels also play substantial roles in mediating the nutritional impacts. Comparable interdisciplinary studies based on primary data at a household level are urgently required to guide effective adaptation, particularly for rural subsistence farmers. Systemization of data collection at the global level is indispensable and urgent. We need to assimilate data from long-term, high-quality agricultural, environmental, socioeconomic, health, and demographic surveillance systems and develop robust statistical methods to establish and validate causal links, quantify impacts, and make reliable predictions that can guide evidence-based health interventions in the future. PMID:26216952

Sex-Linked Behavior: Evolution, Stability, and Variability.

PubMed

Fine, Cordelia; Dupré, John; Joel, Daphna

2017-07-29

Common understanding of human sex-linked behaviors is that proximal mechanisms of genetic and hormonal sex, ultimately shaped by the differential reproductive challenges of ancestral males and females, act on the brain to transfer sex-linked predispositions across generations. Here, we extend the debate on the role of nature and nurture in the development of traits in the lifetime of an individual, to their role in the cross-generation transfer of traits. Advances in evolutionary theory that posit the environment as a source of trans-generational stability, and new understanding of sex effects on the brain, suggest that the cross-generation stability of sex-linked patterns of behavior are sometimes better explained in terms of inherited socioenvironmental conditions, with biological sex fostering intrageneration variability. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sex-Linked Behavior: Evolution, Stability, and Variability.

PubMed

Fine, Cordelia; Dupré, John; Joel, Daphna

2017-09-01

Common understanding of human sex-linked behaviors is that proximal mechanisms of genetic and hormonal sex, ultimately shaped by the differential reproductive challenges of ancestral males and females, act on the brain to transfer sex-linked predispositions across generations. Here, we extend the debate on the role of nature and nurture in the development of traits in the lifetime of an individual, to their role in the cross-generation transfer of traits. Advances in evolutionary theory that posit the environment as a source of trans-generational stability, and new understanding of sex effects on the brain, suggest that the cross-generation stability of sex-linked patterns of behavior are sometimes better explained in terms of inherited socioenvironmental conditions, with biological sex fostering intrageneration variability. Copyright © 2017 Elsevier Ltd. All rights reserved.

Associations of multi-decadal sea-surface temperature variability with US drought

USGS Publications Warehouse

McCabe, G.J.; Betancourt, J.L.; Gray, S.T.; Palecki, M.A.; Hidalgo, H.G.

2008-01-01

Recent research suggests a link between drought occurrence in the conterminous United States (US) and sea surface temperature (SST) variability in both the tropical Pacific and North Atlantic Oceans on decadal to multidecadal (D2M) time scales. Results show that the Atlantic Multidecadal Oscillation (AMO) is the most consistent indicator of D2M drought variability in the conterminous US during the 20th century, but during the 19th century the tropical Pacific is a more consistent indicator of D2 M drought. The interaction between El Nin??o-Southern Oscillation (ENSO) and the AMO explain a large part of the D2M drought variability in the conterminous US. More modeling studies are needed to reveal possible mechanisms linking low-frequency ENSO variability and the AMO with drought in the conterminous US. ?? 2007 Elsevier Ltd and INQUA.

Allogeneic Bone Marrow Transplantation in Patients With Primary Immunodeficiencies

ClinicalTrials.gov

2009-10-14

Immunologic Deficiency Syndromes; Chediak-Higashi Syndrome; Common Variable Immunodeficiency; Graft Versus Host Disease; X-Linked Lymphoproliferative Syndrome; Familial Erythrophagocytic Lymphohistiocytosis; Hemophagocytic Lymphohistiocytosis; X-linked Agammaglobulinemia; Wiskott-Aldrich Syndrome; Chronic Granulomatous Disease; X-linked Hyper IgM Syndrome; Severe Combined Immunodeficiency; Leukocyte Adhesion Deficiency Syndrome; Virus-Associated Hemophagocytic Syndrome

Design of an optical PPM communication link in the presence of component tolerances

NASA Technical Reports Server (NTRS)

Chen, C.-C.

1988-01-01

A systematic approach is described for estimating the performance of an optical direct detection pulse position modulation (PPM) communication link in the presence of parameter tolerances. This approach was incorporated into the JPL optical link analysis program to provide a useful tool for optical link design. Given a set of system parameters and their tolerance specifications, the program will calculate the nominal performance margin and its standard deviation. Through use of these values, the optical link can be designed to perform adequately even under adverse operating conditions.

Intraindividual variability in cognitive performance in three groups of older adults: cross-domain links to physical status and self-perceived affect and beliefs.

PubMed

Strauss, Esther; MacDonald, Stuart W S; Hunter, Michael; Moll, Alex; Hultsch, David F

2002-11-01

Intraindividual variability of physical status and affect/beliefs as well as their relations with cognition were examined in 3 groups of older adults: healthy elderly, individuals with a nonneurological health-related disturbance (arthritis) and people with neurological compromise (dementia). The findings showed that greater inconsistency in physical performance was observed in groups characterized by central nervous system dysfunction. By contrast, fluctuations in affect appeared to reflect other more transient sources, such as pain. In general, increased inconsistency in non-cognitive domains was associated with poorer cognitive function. There were cross-domain links between inconsistency in physical functioning and fluctuations in cognitive performance, although the nature of the links depended largely upon the neurological status of the individuals. Considered together, the result indicated that measures of cognitive as well as physical variability are important behavioral markers of neurological integrity.

A Figure-of-Merit for Designing High-Performance Inductive Power Transmission Links

PubMed Central

Kiani, Mehdi; Ghovanloo, Maysam

2014-01-01

Power transfer efficiency (PTE) and power delivered to the load (PDL) are two key inductive link design parameters that relate to the power source and driver specs, power loss, transmission range, robustness against misalignment, variations in loading, and interference with other devices. Designers need to strike a delicate balance between these two because designing the link to achieve high PTE will degrade the PDL and vice versa. We are proposing a new figure-of-merit (FoM), which can help designers to find out whether a two-, three-, or four-coil link is appropriate for their particular application and guide them through an iterative design procedure to reach optimal coil geometries based on how they weigh the PTE versus PDL for that application. Three design examples at three different power levels have been presented based on the proposed FoM for implantable microelectronic devices, handheld mobile devices, and electric vehicles. The new FoM suggests that the two-coil links are suitable when the coils are strongly coupled, and a large PDL is needed. Three-coil links are the best when the coils are loosely coupled, the coupling distance varies considerably, and large PDL is necessary. Finally, four-coil links are optimal when the PTE is paramount, the coils are loosely coupled, and their relative distance and alignment are stable. Measurement results support the accuracy of the theoretical design procedure and conclusions. PMID:25382898

A Figure-of-Merit for Designing High-Performance Inductive Power Transmission Links.

PubMed

Kiani, Mehdi; Ghovanloo, Maysam

2012-11-16

Power transfer efficiency (PTE) and power delivered to the load (PDL) are two key inductive link design parameters that relate to the power source and driver specs, power loss, transmission range, robustness against misalignment, variations in loading, and interference with other devices. Designers need to strike a delicate balance between these two because designing the link to achieve high PTE will degrade the PDL and vice versa. We are proposing a new figure-of-merit (FoM), which can help designers to find out whether a two-, three-, or four-coil link is appropriate for their particular application and guide them through an iterative design procedure to reach optimal coil geometries based on how they weigh the PTE versus PDL for that application. Three design examples at three different power levels have been presented based on the proposed FoM for implantable microelectronic devices, handheld mobile devices, and electric vehicles. The new FoM suggests that the two-coil links are suitable when the coils are strongly coupled, and a large PDL is needed. Three-coil links are the best when the coils are loosely coupled, the coupling distance varies considerably, and large PDL is necessary. Finally, four-coil links are optimal when the PTE is paramount, the coils are loosely coupled, and their relative distance and alignment are stable. Measurement results support the accuracy of the theoretical design procedure and conclusions.

Screening and Identification of a Phage Display Derived Peptide That Specifically Binds to the CD44 Protein Region Encoded by Variable Exons.

PubMed

Zhang, Dan; Jia, Huan; Li, Weiming; Hou, Yingchun; Lu, Shaoying; He, Shuixiang

2016-01-01

CD44, especially the isoforms with variable exons (CD44v), is a promising biomarker for the detection of cancer. To develop a CD44v-specific probe, we screened a 7-mer phage peptide library against the CD44v3-v10 protein using an improved subtractive method. The consensus sequences with the highest frequency (designated CV-1) emerged after four rounds of panning. The binding affinity and specificity of the CV-1 phage and the synthesized peptide for the region of CD44 encoded by the variable exons were confirmed using enzyme-linked immunosorbent assay and competitive inhibition assays. Furthermore, the binding of the CV-1 probe to gastric cancer cells and tissues was validated using immunofluorescence and immunohistochemistry assays. CV-1 sensitively and specifically bound to CD44v on cancer cells and tissues. Thus, CV-1 has the potential to serve as a promising probe for cancer molecular imaging and target therapy. © 2015 Society for Laboratory Automation and Screening.

Adaptive data rate SSMA system for personal and mobile satellite communications

NASA Technical Reports Server (NTRS)

Ikegami, Tetsushi; Takahashi, Takashi; Arakaki, Yoshiya; Wakana, Hiromitsu

1995-01-01

An adaptive data rate SSMA (spread spectrum multiple access) system is proposed for mobile and personal multimedia satellite communications without the aid of system control earth stations. This system has a constant occupied bandwidth and has variable data rates and processing gains to mitigate communication link impairments such as fading, rain attenuation and interference as well as to handle variable data rate on demand. Proof of concept hardware for 6MHz bandwidth transponder is developed, that uses offset-QPSK (quadrature phase shift keying) and MSK (minimum shift keying) for direct sequence spread spectrum modulation and handle data rates of 4k to 64kbps. The RS422 data interface, low rate voice and H.261 video codecs are installed. The receiver is designed with coherent matched filter technique to achieve fast code acquisition, AFC (automatic frequency control) and coherent detection with minimum hardware losses in a single matched filter circuit. This receiver structure facilitates variable data rate on demand during a call. This paper shows the outline of the proposed system and the performance of the prototype equipment.

Allelic variation of the FRMD7 gene in congenital idiopathic nystagmus.

PubMed

Self, James E; Shawkat, Fatima; Malpas, Crispin T; Thomas, N Simon; Harris, Christopher M; Hodgkins, Peter R; Chen, Xiaoli; Trump, Dorothy; Lotery, Andrew J

2007-09-01

To perform a genotype-phenotype correlation study in an X-linked congenital idiopathic nystagmus pedigree (pedigree 1) and to assess the allelic variance of the FRMD7 gene in congenital idiopathic nystagmus. Subjects from pedigree 1 underwent detailed clinical examination including nystagmology. Screening of FRMD7 was undertaken in pedigree 1 and in 37 other congenital idiopathic nystagmus probands and controls. Direct sequencing confirmed sequence changes. X-inactivation studies were performed in pedigree 1. The nystagmus phenotype was extremely variable in pedigree 1. We identified 2 FRMD7 mutations. However, 80% of X-linked families and 96% of simplex cases showed no mutations. X-inactivation studies demonstrated no clear causal link between skewing and variable penetrance. We confirm profound phenotypic variation in X-linked congenital idiopathic nystagmus pedigrees. We demonstrate that other congenital nystagmus genes exist besides FRMD7. We show that the role of X inactivation in variable penetrance is unclear in congenital idiopathic nystagmus. Clinical Relevance We demonstrate that phenotypic variation of nystagmus occurs in families with FRMD7 mutations. While FRMD7 mutations may be found in some cases of X-linked congenital idiopathic nystagmus, the diagnostic yield is low. X-inactivation assays are unhelpful as a test for carrier status for this disease.

X-linked juvenile retinoschisis in a consanguineous family: phenotypic variability and report of a homozygous female patient.

PubMed

Gliem, Martin; Holz, Frank G; Stöhr, Heidi; Weber, Bernhard H F; Charbel Issa, Peter

2014-12-01

To describe the phenotypic variability in a consanguineous family with genetically confirmed X-linked retinoschisis. Five patients, including one homozygous female, were characterized by clinical examination, optical coherence tomography, fundus autofluorescence, mapping of macular pigment optical density, electroretinography, and DNA testing. The 36-year-old male index patient showed a ring of enhanced autofluorescence and outer retinal atrophy on optical coherence tomography. Electroretinography testing revealed a reduced a/b ratio. His mother presented with a central atrophic retina with markedly reduced autofluorescence signal and a surrounding ring of enhanced autofluorescence. The 40-year-old brother of the index patient and his 2 sons showed characteristic signs for X-linked retinoschisis, including retinal schisis and a reduced a/b ratio. Genetic testing revealed a c.293C>A mutation in the RS1 gene in all affected family members while the mother of the index patient was homozygous for this mutation. X-linked retinoschisis can present with a wide phenotypic variability. Here, detailed family history and genetic testing established the diagnosis of X-linked retinoschisis despite striking differences in phenotypic presentation in affected subjects, homozygosity of one affected female, and seemingly dominant inheritance in three subsequent generations because of multiple consanguinity.

Sonic Boom Mitigation Through Aircraft Design and Adjoint Methodology

NASA Technical Reports Server (NTRS)

Rallabhandi, Siriam K.; Diskin, Boris; Nielsen, Eric J.

2012-01-01

This paper presents a novel approach to design of the supersonic aircraft outer mold line (OML) by optimizing the A-weighted loudness of sonic boom signature predicted on the ground. The optimization process uses the sensitivity information obtained by coupling the discrete adjoint formulations for the augmented Burgers Equation and Computational Fluid Dynamics (CFD) equations. This coupled formulation links the loudness of the ground boom signature to the aircraft geometry thus allowing efficient shape optimization for the purpose of minimizing the impact of loudness. The accuracy of the adjoint-based sensitivities is verified against sensitivities obtained using an independent complex-variable approach. The adjoint based optimization methodology is applied to a configuration previously optimized using alternative state of the art optimization methods and produces additional loudness reduction. The results of the optimizations are reported and discussed.

An event-based vibration control for a two-link flexible robotic arm: Numerical and experimental observations

NASA Astrophysics Data System (ADS)

Özer, Abdullah; Eren Semercigil, S.

2008-06-01

Flexible robot manipulators have numerous advantages over their rigid counterparts. They have increased payload-to-weight ratio, they run at higher speeds, use less energy and smaller actuators, and they are safer during interaction with their environments. On the other hand, light design combined with external effects result in components which can oscillate with excessive amplitudes. These oscillations cause deviation from the desired path and long idle periods between tasks in order to perform the intended operation safely and accurately. This paper is on an investigation into the effectiveness of a vibration control technique for a two-link flexible robotic arm. Variable stiffness control (VSC) technique is used to control the excessive oscillations. Owing to its dissipative nature, the technique is stable, it is relatively insensitive to significant parameter changes and suitable to be implemented on existing robots. This research considers that the source of the flexibility is either the joints or the links or both. Simulation results of the response of the arm are presented to show the versatility of the proposed control technique. Experiments are performed on a laboratory prototype and the results are presented to test the validity of simulations.

Neuman systems model-based research: an integrative review project.

PubMed

Fawcett, J; Giangrande, S K

2001-07-01

The project integrated Neuman systems model-based research literature. Two hundred published studies were located. This article is limited to the 59 full journal articles and 3 book chapters identified. A total of 37% focused on prevention interventions; 21% on perception of stressors; and 10% on stressor reactions. Only 50% of the reports explicitly linked the model with the study variables, and 61% did not include conclusions regarding model utility or credibility. No programs of research were identified. Academic courses and continuing education workshops are needed to help researchers design programs of Neuman systems model-based research and better explicate linkages between the model and the research.

Maximizing ecological and evolutionary insight in bisulfite sequencing data sets

PubMed Central

Lea, Amanda J.; Vilgalys, Tauras P.; Durst, Paul A.P.; Tung, Jenny

2017-01-01

Preface Genome-scale bisulfite sequencing approaches have opened the door to ecological and evolutionary studies of DNA methylation in many organisms. These approaches can be powerful. However, they introduce new methodological and statistical considerations, some of which are particularly relevant to non-model systems. Here, we highlight how these considerations influence a study’s power to link methylation variation with a predictor variable of interest. Relative to current practice, we argue that sample sizes will need to increase to provide robust insights. We also provide recommendations for overcoming common challenges and an R Shiny app to aid in study design. PMID:29046582

A solar diameter metrology measurement: the Picard microsatellite program

NASA Astrophysics Data System (ADS)

Damé, Luc; Brun, Jean-Francis; Cugnet, David; Derrien, Marc; Leroy, Claude; Meftah, Mustapha; Meissonnier, Mireille; Porteneuve, Jacques

2017-11-01

The PICARD microsatellite mission will provide 3 to 4 years simultaneous measurements of the solar diameter, differential rotation and solar constant to investigate the nature of their relations and variabilities. The major instrument, SODISM, is a whole Sun imaging telescope of Ø110 mm which will deliver an absolute measure (better than 4 mas) of the solar diameter and solar shape. Now in Phase B, PICARD is expected to be launched by 2005. We recall the scientific goals linked to the diameter measurement with interest for Earth Climate, Space Weather and Helioseismology, present the instrument optical concept and design, and give a brief overview of the program aspects.

Choice between Single and Multiple Reinforcers in Concurrent-Chains Schedules

ERIC Educational Resources Information Center

Mazur, James E.

2006-01-01

Pigeons responded on concurrent-chains schedules with equal variable-interval schedules as initial links. One terminal link delivered a single reinforcer after a fixed delay, and the other terminal link delivered either three or five reinforcers, each preceded by a fixed delay. Some conditions included a postreinforcer delay after the single…

Temporal Context in Concurrent Chains: I. Terminal-Link Duration

ERIC Educational Resources Information Center

Grace, Randolph C.

2004-01-01

Two experiments are reported in which the ratio of the average times spent in the terminal and initial links ("Tt/Ti") in concurrent chains was varied. In Experiment 1, pigeons responded in a three-component procedure in which terminal-link variable-interval schedules were in constant ratio, but their average duration increased across components…

Supersonic Wing Optimization Using SpaRibs

NASA Technical Reports Server (NTRS)

Locatelli, David; Mulani, Sameer B.; Liu, Qiang; Tamijani, Ali Y.; Kapania, Rakesh K.

2014-01-01

This research investigates the advantages of using curvilinear spars and ribs, termed SpaRibs, to design a supersonic aircraft wing-box in comparison to the use of classic design concepts that employ straight spars and ribs. The objective is to achieve a more efficient load-bearing mechanism and to passively control the deformation of the structure under the flight loads. Moreover, the use of SpaRibs broadens the design space and allows for natural frequencies and natural mode shape tailoring. The SpaRibs concept is implemented in a new optimization MATLAB-based framework referred to as EBF3SSWingOpt. This optimization scheme performs both the sizing and the shaping of the internal structural elements, connecting the optimizer with the analysis software. The shape of the SpaRibs is parametrically defined using the so called Linked Shape method. Each set of SpaRibs is placed in a one by one square domain of the natural space. The set of curves is subsequently transformed in the physical space for creating the wing structure geometry layout. The shape of each curve of each set is unique; however, mathematical relations link the curvature in an effort to reduce the number of design variables. The internal structure of a High Speed Commercial Transport aircraft concept developed by Boeing is optimized subjected to stress, subsonic flutter and supersonic flutter constraints. The results show that the use of the SpaRibs allows for the reduction of the aircraft's primary structure weight without violating the constraints. A weight reduction of about 15 percent is observed.

Probabilistic micromechanics of woven ceramic matrix composites

NASA Astrophysics Data System (ADS)

Goldsmith, Marlana

Woven ceramic matrix composites are a special class of composite materials that are of current interest for harsh thermo-structural conditions such as those encountered by hypersonic vehicle systems and turbine engine components. Testing of the materials is expensive, especially as materials are constantly redesigned. Randomness in the tow architecture, as well as the randomly shaped and spaced voids that are produced as a result of the manufacturing process, are features that contribute to variability in stiffness and strength. The goal of the research is to lay a foundation in which characteristics of the geometry can be translated into material properties. The research first includes quantifying the architectural variability based on 2D micrographs of a 5 harness satin CVI (Chemical Vapor Infiltration) SiC/SiC composite. The architectural variability is applied to a 2D representative volume element (RVE) in order to evaluate which aspects of the architecture are important to model in order to capture the variability found in the cross sections. Tow width, tow spacing, and tow volume fraction were found to have some effect on the variability, but voids were found to have a large influence on transverse stiffness, and a separate study was conducted to determine which characteristics of the voids are most critical to model. It was found that the projected area of the void perpendicular to the transverse direction and the number of voids modeled had a significant influence on the stiffness. The effect of varying architecture on the variability of in-plane tensile strength was also studied using the Brittle Cracking Model for Concrete in the commercial finite element software, Abaqus. A maximum stress criterion is used to evaluate failure, and the stiffness of failed elements is gradually degraded such that the energy required to open a crack (fracture energy) is dissipated during this degradation process. While the varying architecture did not create variability in the in-plane stiffness, it does contribute significantly to the variability of in-plane strength as measured by a 0.02% offset method. Applying spatially random strengths for the constituents did not contribute to variability in strength as measured by the 0.02% offset. The results of this research may be of interest to those designing materials, as well as those using the material in their design. Having an idea about which characteristics of the architecture affect variability in stiffness may provide guidance to the material designer with respect to which aspects of the architecture can be controlled or improved to decrease the variability of the material properties. The work will also be useful to those desiring to use the complex materials by determining how to link the architectural properties to the mechanical properties with the ultimate goal of reducing the required number of tests.

When He Said Linking, He Really Meant Linking

ERIC Educational Resources Information Center

Chudnov, Daniel

2009-01-01

There are many reasons to improve web links, starting with their design. The author tends to think about "design" on the web in terms of two things: (1) graphic/industrial design; and (2) human usability. A nice, clean URI (uniform resource identifier) that does not change, is readable to humans, is amenable to common web behaviors such as…

Back-support large laser mirror unit: mounting modeling and analysis

NASA Astrophysics Data System (ADS)

Wang, Hui; Zhang, Zheng; Long, Kai; Liu, Tianye; Li, Jun; Liu, Changchun; Xiong, Zhao; Yuan, Xiaodong

2018-01-01

In high-power laser system, the surface wavefront of large optics has a close link with its structure design and mounting method. The back-support transport mirror design is presently being investigated as a means in China's high-power laser system to hold the optical component firmly while minimizing the distortion of its reflecting surface. We have proposed a comprehensive analytical framework integrated numerical modeling and precise metrology for the mirror's mounting performance evaluation while treating the surface distortion as a key decision variable. The combination of numerical simulation and field tests demonstrates that the comprehensive analytical framework provides a detailed and accurate approach to evaluate the performance of the transport mirror. It is also verified that the back-support transport mirror is effectively compatible with state-of-the-art optical quality specifications. This study will pave the way for future research to solidify the design of back-support large laser optics in China's next generation inertial confinement fusion facility.

Neurosurgery Residency Websites: A Critical Evaluation.

PubMed

Skovrlj, Branko; Silvestre, Jason; Ibeh, Chinwe; Abbatematteo, Joseph M; Mocco, J

2015-09-01

To evaluate the accessibility of educational and recruitment content of Neurosurgery Residency Websites (NRWs). Program lists from the Fellowship and Residency Electronic Interactive Database (FREIDA), Electronic Residency Application Service (ERAS), and the American Association of Neurological Surgeons (AANS) were accessed for the 2015 Match. These databases were assessed for accessibility of information and responsive program contacts. Presence of online recruitment and education variables was assessed, and correlations between program characteristics and website comprehensiveness were made. All 103 neurosurgery residency programs had an NRW. The AANS database provided the most number of viable website links with 65 (63%). No links existed for 5 (5%) programs. A minority of programs contacts responded via e-mail (46%). A minority of recruitment (46%) and educational (49%) variables were available on the NRWs. Larger programs, as defined by the number of yearly residency spots and clinical faculty, maintained greater online content than smaller programs. Similar trends were seen with programs affiliated with a ranked medical school and hospital. Multiple prior studies have demonstrated that medical students applying to neurosurgery rely heavily on residency program websites. As such, the paucity of content on NRWs allows for future opportunity to optimize online resources for neurosurgery training. Making sure that individual programs provide relevant content, make the content easier to find and adhere to established web design principles could increase the usability of NRWs. Copyright © 2015 Elsevier Inc. All rights reserved.

Essential competencies in entry-level pediatric physical therapy education.

PubMed

Rapport, Mary Jane; Furze, Jennifer; Martin, Kathy; Schreiber, Joe; Dannemiller, Lisa A; Dibiasio, Paula A; Moerchen, Victoria A

2014-01-01

The Section on Pediatrics (SoP) convened an Education Summit in July 2012 to examine, discuss, and respond to documented inconsistencies and challenges in teaching pediatric physical therapy (PT) content in entry-level professional education programs. Despite previous attempts by the SoP to provide guidance around teaching pediatric PT, variability continued to be extensive across programs. This article presents the core competencies developed out of the Summit to inform pediatric content in the entry-level PT curriculum. In addition, the core competencies were linked to teaching strategies, learning activities, assessment outcomes, and curricular structures. Consensus was reached on 5 core competencies that represent a knowledge base essential to all graduates of PT programs. In contrast to prior SoP documents, these competencies were specifically designed to focus on knowledge and skills unique to pediatric practice but essential for all graduates of accredited entry-level PT education programs. For more insights from the authors, see Supplemental Digital Content 1, at http://links.lww.com/PPT/A50.

Dynamic modelling and adaptive robust tracking control of a space robot with two-link flexible manipulators under unknown disturbances

NASA Astrophysics Data System (ADS)

Yang, Xinxin; Ge, Shuzhi Sam; He, Wei

2018-04-01

In this paper, both the closed-form dynamics and adaptive robust tracking control of a space robot with two-link flexible manipulators under unknown disturbances are developed. The dynamic model of the system is described with assumed modes approach and Lagrangian method. The flexible manipulators are represented as Euler-Bernoulli beams. Based on singular perturbation technique, the displacements/joint angles and flexible modes are modelled as slow and fast variables, respectively. A sliding mode control is designed for trajectories tracking of the slow subsystem under unknown but bounded disturbances, and an adaptive sliding mode control is derived for slow subsystem under unknown slowly time-varying disturbances. An optimal linear quadratic regulator method is proposed for the fast subsystem to damp out the vibrations of the flexible manipulators. Theoretical analysis validates the stability of the proposed composite controller. Numerical simulation results demonstrate the performance of the closed-loop flexible space robot system.

Microeconomics of process control in semiconductor manufacturing

NASA Astrophysics Data System (ADS)

Monahan, Kevin M.

2003-06-01

Process window control enables accelerated design-rule shrinks for both logic and memory manufacturers, but simple microeconomic models that directly link the effects of process window control to maximum profitability are rare. In this work, we derive these links using a simplified model for the maximum rate of profit generated by the semiconductor manufacturing process. We show that the ability of process window control to achieve these economic objectives may be limited by variability in the larger manufacturing context, including measurement delays and process variation at the lot, wafer, x-wafer, x-field, and x-chip levels. We conclude that x-wafer and x-field CD control strategies will be critical enablers of density, performance and optimum profitability at the 90 and 65nm technology nodes. These analyses correlate well with actual factory data and often identify millions of dollars in potential incremental revenue and cost savings. As an example, we show that a scatterometry-based CD Process Window Monitor is an economically justified, enabling technology for the 65nm node.

A flight test design for studying airborne applications of air to ground duplex data link communications

NASA Technical Reports Server (NTRS)

Scanlon, Charles H.

1988-01-01

The Automatic En Route Air Traffic Control (AERA) and the Advanced Automated System (AAS) of the NAS plan, call for utilization of data links for such items as computer generated flight clearances, enroute minimum safe altitude warnings, sector probes, out of conformance check, automated flight services, and flow management of advisories. A major technical challenge remaining is the integration, flight testing, and validation of data link equipment and procedures in the aircraft cockpit. The flight test organizational chart, was designed to have the airplane side of data link experiments implemented in the NASA Langley Research Center (LaRC) experimental Boeing 737 airplane. This design would enable investigations into implementation of data link equipment and pilot interface, operations, and procedures. The illustrated ground system consists of a work station with links to a national weather database and a data link transceiver system. The data link transceiver system could be a Mode-S transponder, ACARS, AVSAT, or another type of radio system such as the military type HF data link. The airborne system was designed so that a data link transceiver, workstation, and touch panel could be interfaced with an input output processor to the aircraft system bus and thus have communications access to other digital airplane systems.

Enhanced production of medicinal polysaccharide by submerged fermentation of Lingzhi or Reishi medicinal mushroom Ganoderma lucidium (W.Curt.:Fr.) P. Karst. Using statistical and evolutionary optimization methods.

PubMed

Baskar, Gurunathan; Sathya, Shree Rajesh K

2011-01-01

Statistical and evolutionary optimization of media composition was employed for the production of medicinal exopolysaccharide (EPS) by Lingzhi or Reishi medicinal mushroom Ganoderma lucidium MTCC 1039 using soya bean meal flour as low-cost substrate. Soya bean meal flour, ammonium chloride, glucose, and pH were identified as the most important variables for EPS yield using the two-level Plackett-Burman design and further optimized using the central composite design (CCD) and the artificial neural network (ANN)-linked genetic algorithm (GA). The high value of coefficient of determination of ANN (R² = 0.982) indicates that the ANN model was more accurate than the second-order polynomial model of CCD (R² = 0.91) for representing the effect of media composition on EPS yield. The predicted optimum media composition using ANN-linked GA was soybean meal flour 2.98%, glucose 3.26%, ammonium chloride 0.25%, and initial pH 7.5 for the maximum predicted EPS yield of 1005.55 mg/L. The experimental EPS yield obtained using the predicted optimum media composition was 1012.36 mg/L, which validates the high degree of accuracy of evolutionary optimization for enhanced production of EPS by submerged fermentation of G. lucidium.

An efficient sensitivity analysis method for modified geometry of Macpherson suspension based on Pearson correlation coefficient

NASA Astrophysics Data System (ADS)

Shojaeefard, Mohammad Hasan; Khalkhali, Abolfazl; Yarmohammadisatri, Sadegh

2017-06-01

The main purpose of this paper is to propose a new method for designing Macpherson suspension, based on the Sobol indices in terms of Pearson correlation which determines the importance of each member on the behaviour of vehicle suspension. The formulation of dynamic analysis of Macpherson suspension system is developed using the suspension members as the modified links in order to achieve the desired kinematic behaviour. The mechanical system is replaced with an equivalent constrained links and then kinematic laws are utilised to obtain a new modified geometry of Macpherson suspension. The equivalent mechanism of Macpherson suspension increased the speed of analysis and reduced its complexity. The ADAMS/CAR software is utilised to simulate a full vehicle, Renault Logan car, in order to analyse the accuracy of modified geometry model. An experimental 4-poster test rig is considered for validating both ADAMS/CAR simulation and analytical geometry model. Pearson correlation coefficient is applied to analyse the sensitivity of each suspension member according to vehicle objective functions such as sprung mass acceleration, etc. Besides this matter, the estimation of Pearson correlation coefficient between variables is analysed in this method. It is understood that the Pearson correlation coefficient is an efficient method for analysing the vehicle suspension which leads to a better design of Macpherson suspension system.

SAFARI digital processing unit: performance analysis of the SpaceWire links in case of a LEON3-FT based CPU

NASA Astrophysics Data System (ADS)

Giusi, Giovanni; Liu, Scige J.; Di Giorgio, Anna M.; Galli, Emanuele; Pezzuto, Stefano; Farina, Maria; Spinoglio, Luigi

2014-08-01

SAFARI (SpicA FAR infrared Instrument) is a far-infrared imaging Fourier Transform Spectrometer for the SPICA mission. The Digital Processing Unit (DPU) of the instrument implements the functions of controlling the overall instrument and implementing the science data compression and packing. The DPU design is based on the use of a LEON family processor. In SAFARI, all instrument components are connected to the central DPU via SpaceWire links. On these links science data, housekeeping and commands flows are in some cases multiplexed, therefore the interface control shall be able to cope with variable throughput needs. The effective data transfer workload can be an issue for the overall system performances and becomes a critical parameter for the on-board software design, both at application layer level and at lower, and more HW related, levels. To analyze the system behavior in presence of the expected SAFARI demanding science data flow, we carried out a series of performance tests using the standard GR-CPCI-UT699 LEON3-FT Development Board, provided by Aeroflex/Gaisler, connected to the emulator of the SAFARI science data links, in a point-to-point topology. Two different communication protocols have been used in the tests, the ECSS-E-ST-50-52C RMAP protocol and an internally defined one, the SAFARI internal data handling protocol. An incremental approach has been adopted to measure the system performances at different levels of the communication protocol complexity. In all cases the performance has been evaluated by measuring the CPU workload and the bus latencies. The tests have been executed initially in a custom low level execution environment and finally using the Real- Time Executive for Multiprocessor Systems (RTEMS), which has been selected as the operating system to be used onboard SAFARI. The preliminary results of the carried out performance analysis confirmed the possibility of using a LEON3 CPU processor in the SAFARI DPU, but pointed out, in agreement with previous similar studies, the need of carefully designing the overall architecture to implement some of the DPU functionalities on additional processing devices.

UniPrime2: a web service providing easier Universal Primer design.

PubMed

Boutros, Robin; Stokes, Nicola; Bekaert, Michaël; Teeling, Emma C

2009-07-01

The UniPrime2 web server is a publicly available online resource which automatically designs large sets of universal primers when given a gene reference ID or Fasta sequence input by a user. UniPrime2 works by automatically retrieving and aligning homologous sequences from GenBank, identifying regions of conservation within the alignment, and generating suitable primers that can be used to amplify variable genomic regions. In essence, UniPrime2 is a suite of publicly available software packages (Blastn, T-Coffee, GramAlign, Primer3), which reduces the laborious process of primer design, by integrating these programs into a single software pipeline. Hence, UniPrime2 differs from previous primer design web services in that all steps are automated, linked, saved and phylogenetically delimited, only requiring a single user-defined gene reference ID or input sequence. We provide an overview of the web service and wet-laboratory validation of the primers generated. The system is freely accessible at: http://uniprime.batlab.eu. UniPrime2 is licenced under a Creative Commons Attribution Noncommercial-Share Alike 3.0 Licence.

Variable penetrance of hypogonadism in a sibship with Kallmann syndrome due to a deletion of the KAL gene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parenti, G.; Rizzolo, M.G.; Ghezzi, M.

We report on the clinical and molecular characterization of 3 sibs with X-linked ichthyosis and variable expression of Kallmann syndrome. One of the affected brothers had mild hyposmia and showed normal pubertal progression. However, we demonstrated the same partial deletion of the X-linked Kallmann gene, sparing the first exon in the mildly affected patient as well as in one of his severely affected brothers. 13 refs., 1 fig., 1 tab.

Dielectric Characteristics of Microstructural Changes and Property Evolution in Engineered Materials

NASA Astrophysics Data System (ADS)

Clifford, Jallisa Janet

Heterogeneous materials are increasingly used in a wide range of applications such as aerospace, civil infrastructure, fuel cells and many others. The ability to take properties from two or more materials to create a material with properties engineered to needs is always very attractive. Hence heterogeneous materials are evolving into more complex formulations in multiple disciplines. Design of microstructure at multiple scales control the global functional properties of these materials and their structures. However, local microstructural changes do not directly cause a proportional change to the global properties (such as strength and stiffness). Instead, local changes follow an evolution process including significant interactions. Therefore, in order to understand property evolution of engineered materials, microstructural changes need to be effectively captured. Characterizing these changes and representing them by material variables will enable us to further improve our material level understanding. In this work, we will demonstrate how microstructural features of heterogeneous materials can be described quantitatively using broadband dielectric spectroscopy (BbDS). The frequency dependent dielectric properties can capture the change in material microstructure and represent these changes in terms of material variables, such as complex permittivity. These changes in terms of material properties can then be linked to a number of different conditions, such as increasing damage due to impact or fatigue. Two different broadband dielectric spectroscopy scanning modes are presented: bulk measurements and continuous scanning to measure dielectric property change as a function of position across the specimen. In this study, we will focus on ceramic materials and fiber reinforced polymer matrix composites as test bed material systems. In the first part of the thesis, we will present how different micro-structural design of porous ceramic materials can be captured quantitatively using BbDS. These materials are typically used in solid oxide fuel cells (SOFC). Results show significant effect of microstructural design on material properties at multiple temperatures (up to 800 °C). In the later part of the thesis, we will focus on microstructural changes of fiber reinforced composite materials due to impact and static loading. The changes in dielectric response can then be linked to the bulk mechanical properties of the material and various damage modes. Observing trends in dielectric response enables us to further determine local mechanisms and distribution of properties throughout the damaged specimens. A 3D X-ray microscope and a digital microscope have been used to visualize these changes in material microstructure and validate experimental observations. The increase in damage observed in the material microstructure can then also be linked to the changes in dielectric response. Results show that BbDS is an extremely useful tool for identifying microstructural changes within a heterogeneous material and particularly useful in relating remaining properties. Dielectric material variables can be used directly in property degradation laws and help develop a framework for future predictive modeling methodologies.

Statistical link between external climate forcings and modes of ocean variability

NASA Astrophysics Data System (ADS)

Malik, Abdul; Brönnimann, Stefan; Perona, Paolo

2017-07-01

In this study we investigate statistical link between external climate forcings and modes of ocean variability on inter-annual (3-year) to centennial (100-year) timescales using de-trended semi-partial-cross-correlation analysis technique. To investigate this link we employ observations (AD 1854-1999), climate proxies (AD 1600-1999), and coupled Atmosphere-Ocean-Chemistry Climate Model simulations with SOCOL-MPIOM (AD 1600-1999). We find robust statistical evidence that Atlantic multi-decadal oscillation (AMO) has intrinsic positive correlation with solar activity in all datasets employed. The strength of the relationship between AMO and solar activity is modulated by volcanic eruptions and complex interaction among modes of ocean variability. The observational dataset reveals that El Niño southern oscillation (ENSO) has statistically significant negative intrinsic correlation with solar activity on decadal to multi-decadal timescales (16-27-year) whereas there is no evidence of a link on a typical ENSO timescale (2-7-year). In the observational dataset, the volcanic eruptions do not have a link with AMO on a typical AMO timescale (55-80-year) however the long-term datasets (proxies and SOCOL-MPIOM output) show that volcanic eruptions have intrinsic negative correlation with AMO on inter-annual to multi-decadal timescales. The Pacific decadal oscillation has no link with solar activity, however, it has positive intrinsic correlation with volcanic eruptions on multi-decadal timescales (47-54-year) in reconstruction and decadal to multi-decadal timescales (16-32-year) in climate model simulations. We also find evidence of a link between volcanic eruptions and ENSO, however, the sign of relationship is not consistent between observations/proxies and climate model simulations.

High-speed fiber-optic links for distribution of satellite traffic

NASA Technical Reports Server (NTRS)

Daryoush, Afshin S.; Saedi, Reza; Ackerman, Edward; Kunath, Richard; Shalkhauser, Kurt

1990-01-01

Low-loss fiberoptic links are designed for distribution of data and the frequency reference in large-aperture phased-array antennas based on the transmit/receive-level data mixing architecture. In particular, design aspects of a fiberoptic link satisfying the distribution requirements of satellite data traffic are presented. The design is addressed in terms of reactively matched optical transmitter and receiver modules. Analog and digital characterization of a 50-m fiberoptic link realized using these modules indicates the applicability of this architecture as the only viable alternative for distribution of data signals inside a satellite at present. It is demonstrated that the design of a reactive matching modules enhances the link performance. A dynamic range of 88 dB/MHz was measured for analog data over a 500-1000-MHz bandwidth.

The land-use legacy effect: Towards a mechanistic understanding of time-lagged water quality responses to land use/cover.

PubMed

Martin, Sherry L; Hayes, Daniel B; Kendall, Anthony D; Hyndman, David W

2017-02-01

Numerous studies have linked land use/land cover (LULC) to aquatic ecosystem responses, however only a few have included the dynamics of changing LULC in their analysis. In this study, we explicitly recognize changing LULC by linking mechanistic groundwater flow and travel time models to a historical time series of LULC, creating a land-use legacy map. We then illustrate the utility of legacy maps to explore relationships between dynamic LULC and lake water chemistry. We tested two main concepts about mechanisms linking LULC and lake water chemistry: groundwater pathways are an important mechanism driving legacy effects; and, LULC over multiple spatial scales is more closely related to lake chemistry than LULC over a single spatial scale. We applied statistical models to twelve water chemistry variables, ranging from nutrients to relatively conservative ions, to better understand the roles of biogeochemical reactivity and solubility on connections between LULC and aquatic ecosystem response. Our study illustrates how different areas can have long groundwater pathways that represent different LULC than what can be seen on the landscape today. These groundwater pathways delay the arrival of nutrients and other water quality constituents, thus creating a legacy of historic land uses that eventually reaches surface water. We find that: 1) several water chemistry variables are best fit by legacy LULC while others have a stronger link to current LULC, and 2) single spatial scales of LULC analysis performed worse for most variables. Our novel combination of temporal and spatial scales was the best overall model fit for most variables, including SRP where this model explained 54% of the variation. We show that it is important to explicitly account for temporal and spatial context when linking LULC to ecosystem response. Copyright © 2016. Published by Elsevier B.V.

Link and Network Layers Design for Ultra-High-Speed Terahertz-Band Communications Networks

DTIC Science & Technology

2017-01-01

throughput, and identify the optimal parameter values for their design (Sec. 6.2.3). Moreover, we validate and test the scheme with experimental data obtained...LINK AND NETWORK LAYERS DESIGN FOR ULTRA-HIGH- SPEED TERAHERTZ-BAND COMMUNICATIONS NETWORKS STATE UNIVERSITY OF NEW YORK (SUNY) AT BUFFALO JANUARY...TYPE FINAL TECHNICAL REPORT 3. DATES COVERED (From - To) FEB 2015 – SEP 2016 4. TITLE AND SUBTITLE LINK AND NETWORK LAYERS DESIGN FOR ULTRA-HIGH

Changes in Policy Maker Attitudes Toward Active Living Communities Issues in Hawaii, 2007-2013.

PubMed

McGurk, Meghan; Maddock, Jay

2016-10-01

Obesity and lack of physical activity are major public health problems in the United States. Well-designed, active living communities (ALCs) can help support physically active lifestyles. This study assessed attitudes of Hawaii decision makers in 2007 and 2013 to determine if priorities toward ALCs changed. Elected and appointed state and county officials were mailed surveys both years. Respondents rated the importance of 23 specified problems, which included 1 obesity variable and 5 ALC variables. The survey was completed by 126 (70.4%) respondents in 2007 and 117 (60.9%) in 2013. Among the specific problems, only obesity increased in rank from 14th to ninth place. Three variables fell more than 2 places: increasing traffic (fifth to seventh place), poorly planned development and sprawl (seventh to 11th place) and pedestrian safety (12th to 17th place). The other 2 stayed relatively the same: lack of pedestrian walkways, sidewalks, and crosswalks (16th to 15th place) and lack of recreational activities (22nd to 23rd place). Across years, obesity concerns have increased but do not appear to be tied to increases in concern for ALC variables. More education for policymakers on the link between obesity, physical activity, and the built environment is necessary.

Immune Disorder HSCT Protocol

ClinicalTrials.gov

2017-11-17

Immune Deficiency Disorders; Severe Combined Immunodeficiency; Chronic Granulomatous Disease; X-linked Agammaglobulinemia; Wiskott-Aldrich Syndrome; Hyper-IgM; DiGeorge Syndrome; Chediak-Higashi Syndrome; Common Variable Immune Deficiency; Immune Dysregulatory Disorders; Hemophagocytic Lymphohistiocytosis; IPEX; Autoimmune Lymphoproliferative Syndrome; X-linked Lymphoproliferative Syndrome

Combined effects of levels of protection and environmental variables at different spatial resolutions on fish assemblages in a marine protected area.

PubMed

Claudet, Joachim; García-Charton, José Antonio; Lenfant, Philippe

2011-02-01

The links between species-environment relations and species' responses to protection are unclear, but the objectives of marine protected areas (MPAs) are most likely to be achieved when those relations are known and inform MPA design. The components of a species' habitat vary with the spatial resolution of the area considered. We characterized areas at two resolutions: 250 m(2) (transect) and approximately 30,000 m(2) (seascape). We considered three categories of environmental variables: substrate type, bottom complexity, and depth. We sought to determine at which resolution habitat characteristics were a better predictor of abundance and species composition of fishes and whether the relations with environmental variables at either resolution affected species' responses to protection. Habitat features accounted for a larger proportion of spatial variation in species composition and abundances than differences in protection status. This spatial variation was explained best by habitat characteristics at the seascape level than at the transect level. Species' responses to protected areas were specific to particular seascape characteristics, primarily depth, and bottom complexity. Our method may be useful for prioritizing marine areas for protection, designing MPAs, and monitoring their effectiveness. It identified areas that provided natural shelter, areas acting as buffer zones, and areas where fish species were most responsive to protection. The identification of such areas is necessary for cost-effective establishment and monitoring of MPAs. ©2010 Society for Conservation Biology.

Variables Impacting an Academic Pharmacy Career Choice

PubMed Central

Brown, Bonnie K.; Byrd, Debbie C.; Gupchup, Gireesh V.; Mark, Scott M.; Mobley Smith, Miriam A.; Rospond, Raylene M.

2008-01-01

Objectives To identify the variables associated with an academic pharmacy career choice among the following groups: final professional-year doctor of pharmacy (PharmD) students, pharmacy residents, pharmacy faculty members within the first 5 years of academic employment, and clinical pharmacy practitioners. Methods A cross-sectional design Web-based survey instrument was developed using the online tool SurveyMonkey. The survey link was distributed via e-mail and postcards, and data were collected anonymously. Quantitative analyses were used to describe the 2,494 survey respondents and compare their responses to 25 variables associated with an academic pharmacy career choice. Logistic regression models were used to predict the motivators/deterrents associated with an academic pharmacy career choice for each participant group. Results Across all participant groups, the potential need to generate one's salary was the primary deterrent and autonomy, flexibility, and the ability to shape the future of the profession were the primary motivators. Final-year pharmacy students who considered a career in academic pharmacy were significantly deterred by grant writing. The overall sample of participants who considered an academic pharmacy career was more likely to be motivated by the academic environment and opportunities to teach, conduct professional writing and reviews, and participate in course design and/or assessment. Conclusions This study demonstrates specific areas to consider for improved recruitment and retention of pharmacy faculty. For example, providing experiences related to pharmacy academia, such as allowing student participation in teaching and research, may stimulate those individuals' interest in pursuing an academic pharmacy career. PMID:18698388

Knotted optical vortices in exact solutions to Maxwell's equations

NASA Astrophysics Data System (ADS)

de Klerk, Albertus J. J. M.; van der Veen, Roland I.; Dalhuisen, Jan Willem; Bouwmeester, Dirk

2017-05-01

We construct a family of exact solutions to Maxwell's equations in which the points of zero intensity form knotted lines topologically equivalent to a given but arbitrary algebraic link. These lines of zero intensity, more commonly referred to as optical vortices, and their topology are preserved as time evolves and the fields have finite energy. To derive explicit expressions for these new electromagnetic fields that satisfy the nullness property, we make use of the Bateman variables for the Hopf field as well as complex polynomials in two variables whose zero sets give rise to algebraic links. The class of algebraic links includes not only all torus knots and links thereof, but also more intricate cable knots. While the unknot has been considered before, the solutions presented here show that more general knotted structures can also arise as optical vortices in exact solutions to Maxwell's equations.

A review of the evidence regarding associations between attachment theory and experimentally induced pain.

PubMed

Meredith, Pamela Joy

2013-04-01

Theoretical and empirical evidence suggests that adult attachment and pain-related variables are predictably and consistently linked, and that understanding these links may guide pain intervention and prevention efforts. In general, insecure attachment has been portrayed as a risk factor, and secure attachment as a protective factor, for people with chronic pain conditions. In an effort to better understand the relationships among attachment and pain variables, these links have been investigated in pain-free samples using induced-pain techniques. The present paper reviews the available research linking adult attachment and laboratory-induced pain. While the diverse nature of the studies precludes definitive conclusions, together these papers offer support for associations between insecure attachment and a more negative pain experience. The evidence presented in this review highlights areas for further empirical attention, as well as providing some guidance for clinicians who may wish to employ preventive approaches and other interventions informed by attachment theory.

Influence of preonset land atmospheric conditions on the Indian summer monsoon rainfall variability

NASA Astrophysics Data System (ADS)

Rai, Archana; Saha, Subodh K.; Pokhrel, Samir; Sujith, K.; Halder, Subhadeep

2015-05-01

A possible link between preonset land atmospheric conditions and the Indian summer monsoon rainfall (ISMR) is explored. It is shown that, the preonset positive (negative) rainfall anomaly over northwest India, Pakistan, Afghanistan, and Iran is associated with decrease (increase) in ISMR, primarily in the months of June and July, which in turn affects the seasonal mean. ISMR in the months of June and July is also strongly linked with the preonset 2 m air temperature over the same regions. The preonset rainfall/2 m air temperature variability is linked with stationary Rossby wave response, which is clearly evident in the wave activity flux diagnostics. As the predictability of Indian summer monsoon relies mainly on the El Niño-Southern Oscillation (ENSO), the found link may further enhance our ability to predict the monsoon, particularly during a non-ENSO year.

Oscillations and trends of river discharge in the southern Central Andes and linkages with climate variability

NASA Astrophysics Data System (ADS)

Castino, Fabiana; Bookhagen, Bodo; Strecker, Manfred R.

2017-12-01

This study analyzes the discharge variability of small to medium drainage basins (102-104 km2) in the southern Central Andes of NW Argentina. The Hilbert-Huang Transform (HHT) was applied to evaluate non-stationary oscillatory modes of variability and trends, based on four time series of monthly-normalized discharge anomaly between 1940 and 2015. Statistically significant trends reveal increasing discharge during the past decades and document an intensification of the hydrological cycle during this period. An Ensemble Empirical Mode Decomposition (EEMD) analysis revealed that discharge variability in this region can be best described by five quasi-periodic statistically significant oscillatory modes, with mean periods varying from 1 to ∼20 y. Moreover, we show that discharge variability is most likely linked to the phases of the Pacific Decadal Oscillation (PDO) at multi-decadal timescales (∼20 y) and, to a lesser degree, to the Tropical South Atlantic SST anomaly (TSA) variability at shorter timescales (∼2-5 y). Previous studies highlighted a rapid increase in discharge in the southern Central Andes during the 1970s, inferred to have been associated with the global 1976-77 climate shift. Our results suggest that the rapid discharge increase in the NW Argentine Andes coincides with the periodic enhancement of discharge, which is mainly linked to a negative to positive transition of the PDO phase and TSA variability associated with a long-term increasing trend. We therefore suggest that variations in discharge in this region are largely driven by both natural variability and the effects of global climate change. We furthermore posit that the links between atmospheric and hydrologic processes result from a combination of forcings that operate on different spatiotemporal scales.

Population dynamics of Microtus pennsylvanicus in corridor-linked patches

USGS Publications Warehouse

Coffman, C.J.; Nichols, J.D.; Pollock, K.H.

2001-01-01

Corridors have become a key issue in the discussion of conservation planning: however, few empirical data exist on the use of corridors and their effects on population dynamics. The objective of this replicated, population level, capture-re-capture experiment on meadow voles was to estimate and compare population characteristics of voles between (1) corridor-linked fragments, (2) isolated or non-linked fragments, and (3) unfragmented areas. We conducted two field experiments involving 22600 captures of 5700 individuals. In the first, the maintained corridor study, corridors were maintained at the time of fragmentation, and in the second, the constructed corridor study, we constructed corridors between patches that had been fragmented for some period of time. We applied multistate capture-recapture models with the robust design to estimate adult movement and survival rates, population size, temporal variation in population size, recruitment, and juvenile survival rates. Movement rates increased to a greater extent on constructed corridor-linked grids than on the unfragmented or non-linked fragmented grids between the pre- and post-treatment periods. We found significant differences in local survival on the treated (corridor-linked) grids compared to survival on the fragmented and unfragmented grids between the pre- and post-treatment periods. We found no clear pattern of treatment effects on population size or recruitment in either study. However, in both studies, we found that unfragmented grids were more stable than the fragmented grids based on lower temporal variability in population size. To our knowledge, this is the first experimental study demonstrating that corridors constructed between existing fragmented populations can indeed cause increases in movement and associated changes in demography, supporting the use of constructed corridors for this purpose in conservation biology.

In-Field Spatial Variability in the Degradation of the Phenyl-Urea Herbicide Isoproturon Is the Result of Interactions between Degradative Sphingomonas spp. and Soil pH

PubMed Central

Bending, Gary D.; Lincoln, Suzanne D.; Sørensen, Sebastian R.; Morgan, J. Alun W.; Aamand, Jens; Walker, Allan

2003-01-01

Substantial spatial variability in the degradation rate of the phenyl-urea herbicide isoproturon (IPU) [3-(4-isopropylphenyl)-1,1-dimethylurea] has been shown to occur within agricultural fields, with implications for the longevity of the compound in the soil, and its movement to ground- and surface water. The microbial mechanisms underlying such spatial variability in degradation rate were investigated at Deep Slade field in Warwickshire, United Kingdom. Most-probable-number analysis showed that rapid degradation of IPU was associated with proliferation of IPU-degrading organisms. Slow degradation of IPU was linked to either a delay in the proliferation of IPU-degrading organisms or apparent cometabolic degradation. Using enrichment techniques, an IPU-degrading bacterial culture (designated strain F35) was isolated from fast-degrading soil, and partial 16S rRNA sequencing placed it within the Sphingomonas group. Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified bacterial community 16S rRNA revealed two bands that increased in intensity in soil during growth-linked metabolism of IPU, and sequencing of the excised bands showed high sequence homology to the Sphingomonas group. However, while F35 was not closely related to either DGGE band, one of the DGGE bands showed 100% partial 16S rRNA sequence homology to an IPU-degrading Sphingomonas sp. (strain SRS2) isolated from Deep Slade field in an earlier study. Experiments with strains SRS2 and F35 in soil and liquid culture showed that the isolates had a narrow pH optimum (7 to 7.5) for metabolism of IPU. The pH requirements of IPU-degrading strains of Sphingomonas spp. could largely account for the spatial variation of IPU degradation rates across the field. PMID:12571001

A Study Space Analysis and Narrative Review of Trauma-Informed Mediators of Dating Violence.

PubMed

Cascardi, Michele; Jouriles, Ernest N

2018-07-01

Research linking child maltreatment and dating violence in adolescence and emerging adulthood has proliferated in the past two decades; however, the precise mechanisms by which these experiences are related remain elusive. A trauma-informed perspective suggests four particularly promising mediators: maladaptive attachment, emotion regulation difficulties, emotional distress, and hostility. The current article characterizes the status of the empirical literature examining these four mediators using a study space analysis and a narrative review of existing research. An extensive literature search identified 42 papers (44 studies) that met the following criteria: (1) at least one measure of child maltreatment (emotional, physical, sexual, neglect, or exposure to intimate partner violence); (2) a measure of one of the four mediator variables; (3) a measure of dating violence perpetration or victimization; and (4) a sample of adolescents or young adults. The study space analysis suggested several important observations about the research on this topic, including a dearth of studies examining hostility as a mediator and little research using prospective designs or clinical samples. There are also limitations with the conceptualization and measurement of dating violence, child maltreatment, and some of the mediator variables. In addition, few studies examined more than one mediator variable in the same study. The narrative review suggested that maladaptive attachment (specifically insecure attachment styles), emotion regulation difficulties (specifically regulation of the emotion of anger), and emotional distress construed broadly represent promising mediators of the association between child maltreatment and dating violence, but conclusions about mediation must remain tentative given the state of the literature. The discussion offers recommendations for improved theoretical and empirical rigor to advance future research on mechanisms linking child maltreatment and dating violence.

AN IMPROVED STRATEGY FOR REGRESSION OF BIOPHYSICAL VARIABLES AND LANDSAT ETM+ DATA. (R828309)

EPA Science Inventory

Empirical models are important tools for relating field-measured biophysical variables to remote sensing data. Regression analysis has been a popular empirical method of linking these two types of data to provide continuous estimates for variables such as biomass, percent wood...

Conceptual Design Optimization of an Augmented Stability Aircraft Incorporating Dynamic Response and Actuator Constraints

NASA Technical Reports Server (NTRS)

Welstead, Jason; Crouse, Gilbert L., Jr.

2014-01-01

Empirical sizing guidelines such as tail volume coefficients have long been used in the early aircraft design phases for sizing stabilizers, resulting in conservatively stable aircraft. While successful, this results in increased empty weight, reduced performance, and greater procurement and operational cost relative to an aircraft with optimally sized surfaces. Including flight dynamics in the conceptual design process allows the design to move away from empirical methods while implementing modern control techniques. A challenge of flight dynamics and control is the numerous design variables, which are changing fluidly throughout the conceptual design process, required to evaluate the system response to some disturbance. This research focuses on addressing that challenge not by implementing higher order tools, such as computational fluid dynamics, but instead by linking the lower order tools typically used within the conceptual design process so each discipline feeds into the other. In thisresearch, flight dynamics and control was incorporated into the conceptual design process along with the traditional disciplines of vehicle sizing, weight estimation, aerodynamics, and performance. For the controller, a linear quadratic regulator structure with constant gains has been specified to reduce the user input. Coupling all the disciplines in the conceptual design phase allows the aircraft designer to explore larger design spaces where stabilizers are sized according to dynamic response constraints rather than historical static margin and volume coefficient guidelines.

Loop Heat Pipe with Thermal Control Valve as a Variable Thermal Link

NASA Technical Reports Server (NTRS)

Hartenstine, John; Anderson, William G.; Walker, Kara; Dussinger, Pete

2012-01-01

Future lunar landers and rovers will require variable thermal links that allow for heat rejection during the lunar daytime and passively prevent heat rejection during the lunar night. During the lunar day, the thermal management system must reject the waste heat from the electronics and batteries to maintain them below the maximum acceptable temperature. During the lunar night, the heat rejection system must either be shut down or significant amounts of guard heat must be added to keep the electronics and batteries above the minimum acceptable temperature. Since guard heater power is unfavorable because it adds to system size and complexity, a variable thermal link is preferred to limit heat removal from the electronics and batteries during the long lunar night. Conventional loop heat pipes (LHPs) can provide the required variable thermal conductance, but they still consume electrical power to shut down the heat transfer. This innovation adds a thermal control valve (TCV) and a bypass line to a conventional LHP that proportionally allows vapor to flow back into the compensation chamber of the LHP. The addition of this valve can achieve completely passive thermal control of the LHP, eliminating the need for guard heaters and complex controls.

Bias and Bias Correction in Multi-Site Instrumental Variables Analysis of Heterogeneous Mediator Effects

ERIC Educational Resources Information Center

Reardon, Sean F.; Unlu, Faith; Zhu, Pei; Bloom, Howard

2013-01-01

We explore the use of instrumental variables (IV) analysis with a multi-site randomized trial to estimate the effect of a mediating variable on an outcome in cases where it can be assumed that the observed mediator is the only mechanism linking treatment assignment to outcomes, as assumption known in the instrumental variables literature as the…

Estimating the designated use attainment decision error rates of US Environmental Protection Agency's proposed numeric total phosphorus criteria for Florida, USA, colored lakes.

PubMed

McLaughlin, Douglas B

2012-01-01

The utility of numeric nutrient criteria established for certain surface waters is likely to be affected by the uncertainty that exists in the presence of a causal link between nutrient stressor variables and designated use-related biological responses in those waters. This uncertainty can be difficult to characterize, interpret, and communicate to a broad audience of environmental stakeholders. The US Environmental Protection Agency (USEPA) has developed a systematic planning process to support a variety of environmental decisions, but this process is not generally applied to the development of national or state-level numeric nutrient criteria. This article describes a method for implementing such an approach and uses it to evaluate the numeric total P criteria recently proposed by USEPA for colored lakes in Florida, USA. An empirical, log-linear relationship between geometric mean concentrations of total P (a potential stressor variable) and chlorophyll a (a nutrient-related response variable) in these lakes-that is assumed to be causal in nature-forms the basis for the analysis. The use of the geometric mean total P concentration of a lake to correctly indicate designated use status, defined in terms of a 20 µg/L geometric mean chlorophyll a threshold, is evaluated. Rates of decision errors analogous to the Type I and Type II error rates familiar in hypothesis testing, and a 3rd error rate, E(ni) , referred to as the nutrient criterion-based impairment error rate, are estimated. The results show that USEPA's proposed "baseline" and "modified" nutrient criteria approach, in which data on both total P and chlorophyll a may be considered in establishing numeric nutrient criteria for a given lake within a specified range, provides a means for balancing and minimizing designated use attainment decision errors. Copyright © 2011 SETAC.

NASA Langley Atmospheric Science Data Center Toolsets for Airborne Data (TAD): User Interface Design and Development

NASA Astrophysics Data System (ADS)

Beach, A. L., III; Early, A. B.; Chen, G.; Parker, L.

2014-12-01

NASA has conducted airborne tropospheric chemistry studies for about three decades. These field campaigns have generated a great wealth of observations, which are characterized by a wide range of trace gases and aerosol properties. The airborne observational data have often been used in assessment and validation of models and satellite instruments. The ASDC Toolset for Airborne Data (TAD) is being designed to meet the user community needs for manipulating aircraft data for scientific research on climate change and air quality relevant issues. Given the sheer volume of data variables across field campaigns and instruments reporting data on different time scales, this data is often difficult and time-intensive for researchers to analyze. The TAD web application is designed to provide an intuitive user interface (UI) to facilitate quick and efficient discovery from a vast number of airborne variables and data. Users are given the option to search based on high-level parameter groups, individual common names, mission and platform, as well as date ranges. Experienced users can immediately filter by keyword using the global search option. Once the user has chosen their required variables, they are given the option to either request PI data files based on their search criteria or create merged data, i.e. geo-located data from one or more measurement PIs. The purpose of the merged data feature is to allow users to compare data from one flight, as not all data from each flight is taken on the same time scale. Time bases can be continuous or based on the time base from one of the measurement time scales and intervals. After an order is submitted and processed, an ASDC email is sent to the user with a link for data download. The TAD user interface design, application architecture, and proposed future enhancements will be presented.

NEUROPSYCHOLOGICAL PERFORMANCE WITHIN-PERSON VARIABILITY IS ASSOCIATED WITH REDUCED TREATMENT CONSENT CAPACITY

PubMed Central

Gurrera, Ronald J.; Karel, Michele J.; Azar, Armin R.; Moye, Jennifer

2013-01-01

OBJECTIVES The capacity of older adults to make health care decisions is often impaired in dementia and has been linked to performance on specific neuropsychological tasks. Within-person across-test neuropsychological performance variability has been shown to predict future dementia. This study examined the relationship of within-person across-test neuropsychological performance variability to a current construct of treatment decision (consent) capacity. DESIGN Participants completed a neuropsychological test battery and a standardized capacity assessment. Standard scores were used to compute mean neuropsychological performance and within-person across-test variability. SETTING Assessments were performed in the participant’s preferred location (e.g., outpatient clinic office, senior center, or home). PARTICIPANTS Participants were recruited from the community with fliers and advertisements, and consisted of men (N=79) and women (N=80) with (N=83) or without (N=76) significant cognitive impairment. MEASUREMENTS Participants completed the MacArthur Competence Assessment Tool - Treatment (MacCAT-T) and 11 neuropsychological tests commonly used in the cognitive assessment of older individuals. RESULTS Neuropsychological performance and within-person variability were independently associated with continuous and dichotomous measures of capacity, and within-person neuropsychological variability was significantly associated with within-person decisional ability variability. Prevalence of incapacity was greater than expected in participants with and without significant cognitive impairment when decisional abilities were considered separately. CONCLUSIONS These findings are consistent with an emerging construct of consent capacity in which discrete decisional abilities are differentially associated with cognitive processes, and indicate that the sensitivity and accuracy of consent capacity assessments can be improved by evaluating decisional abilities separately. PMID:23831178

Topological properties of robust biological and computational networks

PubMed Central

Navlakha, Saket; He, Xin; Faloutsos, Christos; Bar-Joseph, Ziv

2014-01-01

Network robustness is an important principle in biology and engineering. Previous studies of global networks have identified both redundancy and sparseness as topological properties used by robust networks. By focusing on molecular subnetworks, or modules, we show that module topology is tightly linked to the level of environmental variability (noise) the module expects to encounter. Modules internal to the cell that are less exposed to environmental noise are more connected and less robust than external modules. A similar design principle is used by several other biological networks. We propose a simple change to the evolutionary gene duplication model which gives rise to the rich range of module topologies observed within real networks. We apply these observations to evaluate and design communication networks that are specifically optimized for noisy or malicious environments. Combined, joint analysis of biological and computational networks leads to novel algorithms and insights benefiting both fields. PMID:24789562

A Comparison of PECS and iPad to Teach Requesting to Pre-schoolers with Autistic Spectrum Disorders.

PubMed

Agius, May M; Vance, Margaret

2016-01-01

Few studies have compared the efficacy of the Picture Exchange Communication System (PECS) and iPads used as speech generating devices (SGDs), and none have targeted preschoolers. This study compares the relative efficacy of PECS and an iPad/SGD with three preschool-aged children with autism spectrum disorder and limited functional speech who lived in Malta. The study utilized an adapted alternating treatment design embedded in a multiple baseline design, with requesting of reinforcers as the dependent variable. Visual analysis of the results indicated that all participants required more prompted trials and sessions for the iPad/SGD condition. All participants learned a three step navigational sequence on the iPad. Participant preference probes were inconclusive and were not linked to speed of acquisition of requesting skills. Results suggest that both PECS and an iPad could be appropriate for teaching requesting skills to beginning communicators.

A Simulation Study of Threats to Validity in Quasi-Experimental Designs: Interrelationship between Design, Measurement, and Analysis.

PubMed

Holgado-Tello, Fco P; Chacón-Moscoso, Salvador; Sanduvete-Chaves, Susana; Pérez-Gil, José A

2016-01-01

The Campbellian tradition provides a conceptual framework to assess threats to validity. On the other hand, different models of causal analysis have been developed to control estimation biases in different research designs. However, the link between design features, measurement issues, and concrete impact estimation analyses is weak. In order to provide an empirical solution to this problem, we use Structural Equation Modeling (SEM) as a first approximation to operationalize the analytical implications of threats to validity in quasi-experimental designs. Based on the analogies established between the Classical Test Theory (CTT) and causal analysis, we describe an empirical study based on SEM in which range restriction and statistical power have been simulated in two different models: (1) A multistate model in the control condition (pre-test); and (2) A single-trait-multistate model in the control condition (post-test), adding a new mediator latent exogenous (independent) variable that represents a threat to validity. Results show, empirically, how the differences between both the models could be partially or totally attributed to these threats. Therefore, SEM provides a useful tool to analyze the influence of potential threats to validity.

A Simulation Study of Threats to Validity in Quasi-Experimental Designs: Interrelationship between Design, Measurement, and Analysis

PubMed Central

Holgado-Tello, Fco. P.; Chacón-Moscoso, Salvador; Sanduvete-Chaves, Susana; Pérez-Gil, José A.

2016-01-01

The Campbellian tradition provides a conceptual framework to assess threats to validity. On the other hand, different models of causal analysis have been developed to control estimation biases in different research designs. However, the link between design features, measurement issues, and concrete impact estimation analyses is weak. In order to provide an empirical solution to this problem, we use Structural Equation Modeling (SEM) as a first approximation to operationalize the analytical implications of threats to validity in quasi-experimental designs. Based on the analogies established between the Classical Test Theory (CTT) and causal analysis, we describe an empirical study based on SEM in which range restriction and statistical power have been simulated in two different models: (1) A multistate model in the control condition (pre-test); and (2) A single-trait-multistate model in the control condition (post-test), adding a new mediator latent exogenous (independent) variable that represents a threat to validity. Results show, empirically, how the differences between both the models could be partially or totally attributed to these threats. Therefore, SEM provides a useful tool to analyze the influence of potential threats to validity. PMID:27378991

Remotely adjustable check-valves with an electrochemical release mechanism for implantable biomedical microsystems.

PubMed

Pan, Tingrui; Baldi, Antonio; Ziaie, Babak

2007-06-01

In this paper, we present two remotely adjustable check-valves with an electrochemical release mechanism for implantable biomedical microsystems. These valves allow one to vary the opening pressure set-point and flow resistance over a period of time. The first design consists of a micromachined check-valve array using a SU-8 polymer structural layer deposited on the top of a gold sacrificial layer. The second design is based on a variable length cantilever beam structure with a gold sacrificial layer. The adjustable cantilever-beam structure is fabricated by gold thermo-compression bond of a thin silicon wafer over a glass substrate. In both designs, the evaporated gold can be electrochemically dissolved using a constant DC current via a telemetry link. In the first design the dissolution simply opens up individual outlets, while in the second design, gold anchors are sequentially dissolved hence increasing the effective length of the cantilever beam (reducing the opening pressure). A current density of 35 mA/cm(2) is used to dissolve the gold sacrificial layers. Both gravity and syringe-pump driven flow are used to characterize the valve performance. A multi-stage fluidic performance (e.g. flow resistance and opening pressure) is clearly demonstrated.

Contrasted patterns of selection on MHC-linked microsatellites in natural populations of the Malagasy plague reservoir.

PubMed

Tollenaere, Charlotte; Ivanova, Svilena; Duplantier, Jean-Marc; Loiseau, Anne; Rahalison, Lila; Rahelinirina, Soanandrasana; Brouat, Carine

2012-01-01

Plague (Yersinia pestis infection) is a highly virulent rodent disease that persists in many natural ecosystems. The black rat (Rattus rattus) is the main host involved in the plague focus of the central highlands of Madagascar. Black rat populations from this area are highly resistant to plague, whereas those from areas in which the disease is absent (low altitude zones of Madagascar) are susceptible. Various lines of evidence suggest a role for the Major Histocompatibility Complex (MHC) in plague resistance. We therefore used the MHC region as a candidate for detecting signatures of plague-mediated selection in Malagasy black rats, by comparing population genetic structures for five MHC-linked microsatellites and neutral markers in two sampling designs. We first compared four pairs of populations, each pair including one population from the plague focus and one from the disease-free zone. Plague-mediated selection was expected to result in greater genetic differentiation between the two zones than expected under neutrality and this was observed for one MHC-class I-linked locus (D20Img2). For this marker as well as for four other MHC-linked loci, a geographic pattern of genetic structure was found at local scale within the plague focus. This pattern would be expected if plague selection pressures were spatially variable. Finally, another MHC-class I-linked locus (D20Rat21) showed evidences of balancing selection, but it seems more likely that this selection would be related to unknown pathogens more widely distributed in Madagascar than plague.

Computerized training management system

DOEpatents

Rice, H.B.; McNair, R.C.; White, K.; Maugeri, T.

1998-08-04

A Computerized Training Management System (CTMS) is disclosed for providing a procedurally defined process that is employed to develop accreditable performance based training programs for job classifications that are sensitive to documented regulations and technical information. CTMS is a database that links information needed to maintain a five-phase approach to training-analysis, design, development, implementation, and evaluation independent of training program design. CTMS is designed using R-Base{trademark}, an-SQL compliant software platform. Information is logically entered and linked in CTMS. Each task is linked directly to a performance objective, which, in turn, is linked directly to a learning objective; then, each enabling objective is linked to its respective test items. In addition, tasks, performance objectives, enabling objectives, and test items are linked to their associated reference documents. CTMS keeps all information up to date since it automatically sorts, files and links all data; CTMS includes key word and reference document searches. 18 figs.

Computerized training management system

DOEpatents

Rice, Harold B.; McNair, Robert C.; White, Kenneth; Maugeri, Terry

1998-08-04

A Computerized Training Management System (CTMS) for providing a procedurally defined process that is employed to develop accreditable performance based training programs for job classifications that are sensitive to documented regulations and technical information. CTMS is a database that links information needed to maintain a five-phase approach to training-analysis, design, development, implementation, and evaluation independent of training program design. CTMS is designed using R-Base.RTM., an-SQL compliant software platform. Information is logically entered and linked in CTMS. Each task is linked directly to a performance objective, which, in turn, is linked directly to a learning objective; then, each enabling objective is linked to its respective test items. In addition, tasks, performance objectives, enabling objectives, and test items are linked to their associated reference documents. CTMS keeps all information up to date since it automatically sorts, files and links all data; CTMS includes key word and reference document searches.

Factors associated with improvement in disability-adjusted life years in patients with HIV/AIDS

PubMed Central

Bermudez-Tamayo, Clara; Martin, Jose Jesus Martin; Ruiz-Pérez, Isabel; Lima, Antonio Olry de Labry

2008-01-01

Background The epidemic of HIV/AIDS and treatments that have emerged to alleviate, have brought about a shift in the burden of disease from death to quality of life/disability. The aim was to determine which factors are associated with improvements in the level of health of male and female patients with HIV/AIDS in Andalusia, in terms of disability-adjusted life years. Methods Descriptive study based on a sample group of 8800 people on the Andalusian AIDS register between 1983 and 2004. Dependent variables: Life lost due to premature mortality (YLL), years lost due to disability (YLD) and disability-adjusted life years (DALY). Independent variables: vital state, sex, age at the time of diagnosis, age at the time of death, transmission category, province of residence, AIDS-indicator disease and the period of diagnosis. A bivariate analysis was carried out to find out if the health level variables changed in accordance with the independent variables. Using the independent variables which had a statistically significant link with the level of health variables, a multivariate linear regression model, disaggregated by gender, was constructed. Results Amongst the women, we found a model which explained the level of health of 64.9%: a link was found between a higher level of health (lower DALYs) and not intravenous drug use, the province of residence, being diagnosed during the HAART era and older age at the time of diagnosis. Amongst the men, we found a model which explained the level of health of 64.4%: a link was found between a higher level of health (lower DALYs) and intravenous drug use, the province of residence, being diagnosed during the HAART era and older age at the time of diagnosis. Conclusion A higher level of health (lower DALY) amongst both men and women was found to be linked to not be intravenous drug user, the province of residence, being diagnosed during the HAART era and older age at the time of diagnosis. PMID:18939970

A flight test facility design for examining digital information transfer

NASA Technical Reports Server (NTRS)

Knox, Charles E.

1990-01-01

Information is given in viewgraph form on a flight test facility design for examining digital information transfer. Information is given on aircraft/ground exchange, data link research activities, data link display format, a data link flight test, and the flight test setup.

Does the Neighborhood Context Alter the Link between Youth's After-School Time Activities and Developmental Outcomes? A Multilevel Analysis

ERIC Educational Resources Information Center

Fauth, Rebecca C.; Roth, Jodie L.; Brooks-Gunn, Jeanne

2007-01-01

This article examines links between different measures of after-school time activity participation (5 specific activities and breadth) on youth's developmental outcomes (anxiety/depression, delinquency, and substance use) over 6 years and whether these links are moderated by neighborhood-level variables. The sample (N = 1,315) of 9- and…

Modeling and control of a hydraulically actuated flexible-prismatic link robot

DOE Office of Scientific and Technical Information (OSTI.GOV)

Love, L.; Kress, R.; Jansen, J.

1996-12-01

Most of the research related to flexible link manipulators to date has focused on single link, fixed length, single plane of vibration test beds. In addition, actuation has been predominantly based upon electromagnetic motors. Ironically, these elements are rarely found in the existing industrial long reach systems. This manuscript describes a new hydraulically actuated, long reach manipulator with a flexible prismatic link at Oak Ridge National Laboratory (ORNL). Focus is directed towards both modeling and control of hydraulic actuators as well as flexible links that have variable natural frequencies.

Three Corner Sat Communications System

NASA Technical Reports Server (NTRS)

Anderson, Bobby; Horan, Stephen

2000-01-01

Three Corner Satellite is a constellation of three nanosatellites designed and built by students. New Mexico State University has taken on the design of the communications system for this constellation. The system includes the forward link, return link, and the crosslink. Due to size, mass, power, and financial constraints, we must design a small, light, power efficient, and inexpensive communications system. This thesis presents the design of a radio system to accomplish the data transmission requirements in light of the system constraints. In addition to the hardware design, the operational commands needed by the satellite's on-board computer to control and communicate with the communications hardware will be presented. In order for the hardware to communicate with the ground stations, we will examine the link budgets derived from the radiated power of the transmitters, link distance, data modulation, and data rate for each link. The antenna design for the constellation is analyzed using software and testing the physical antennas on a model satellite. After the analysis and testing, a combination of different systems will meet and exceed the requirements and constraints of the Three Corner Satellite constellation.

Increased variability of stimulus-driven cortical responses is associated with genetic variability in children with and without dyslexia.

PubMed

Centanni, T M; Pantazis, D; Truong, D T; Gruen, J R; Gabrieli, J D E; Hogan, T P

2018-05-26

Individuals with dyslexia exhibit increased brainstem variability in response to sound. It is unknown as to whether increased variability extends to neocortical regions associated with audition and reading, extends to visual stimuli, and whether increased variability characterizes all children with dyslexia or, instead, a specific subset of children. We evaluated the consistency of stimulus-evoked neural responses in children with (N = 20) or without dyslexia (N = 12) as measured by magnetoencephalography (MEG). Approximately half of the children with dyslexia had significantly higher levels of variability in cortical responses to both auditory and visual stimuli in multiple nodes of the reading network. There was a significant and positive relationship between the number of risk alleles at rs6935076 in the dyslexia-susceptibility gene KIAA0319 and the degree of neural variability in primary auditory cortex across all participants. This gene has been linked with neural variability in rodents and in typical readers. These findings indicate that unstable representations of auditory and visual stimuli in auditory and other reading-related neocortical regions are present in a subset of children with dyslexia and support the link between the gene KIAA0319 and the auditory neural variability across children with or without dyslexia. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

A model for AGN variability on multiple time-scales

NASA Astrophysics Data System (ADS)

Sartori, Lia F.; Schawinski, Kevin; Trakhtenbrot, Benny; Caplar, Neven; Treister, Ezequiel; Koss, Michael J.; Urry, C. Megan; Zhang, C. E.

2018-05-01

We present a framework to link and describe active galactic nuclei (AGN) variability on a wide range of time-scales, from days to billions of years. In particular, we concentrate on the AGN variability features related to changes in black hole fuelling and accretion rate. In our framework, the variability features observed in different AGN at different time-scales may be explained as realisations of the same underlying statistical properties. In this context, we propose a model to simulate the evolution of AGN light curves with time based on the probability density function (PDF) and power spectral density (PSD) of the Eddington ratio (L/LEdd) distribution. Motivated by general galaxy population properties, we propose that the PDF may be inspired by the L/LEdd distribution function (ERDF), and that a single (or limited number of) ERDF+PSD set may explain all observed variability features. After outlining the framework and the model, we compile a set of variability measurements in terms of structure function (SF) and magnitude difference. We then combine the variability measurements on a SF plot ranging from days to Gyr. The proposed framework enables constraints on the underlying PSD and the ability to link AGN variability on different time-scales, therefore providing new insights into AGN variability and black hole growth phenomena.

Nonlinear Optics Technology. Volume 2. Phase Conjugated Optical Communication Link. Phase 3

DTIC Science & Technology

1991-01-12

who performed the mission analysis, Mr. Larry A. Dozal whose laboratory assistance was vital to both the comm link experiments and mechanical design of...further the understanding of FWM PC comm link physics and to determine design requirements for a fieldable system. The system model demonstrated that...neterodyne receiver using photorefractive iaterial was also designed , fabricated, and characterized. The efficiency o heterodyne mixing of an aberrated

Controller Evaluation of Initial Data Link En Route Air Traffic Control Services: ISSS Design Development. Study 1

DTIC Science & Technology

1994-05-01

services developed for transmission using Data Link technology . Candidate designs for five ATC services and functions for the new Initial Sector Suite System...clarify suspected confusions to avoid further congestion. 1.2.2 Data Link Communications . Data Link is a digital communications technology which is being... developed as a supplement to traditional voice radio for two-way, air-ground ATC communications and other applications. As shown in figure 1, Data Link

Land Use Change on Household Farms in the Ecuadorian Amazon: Design and Implementation of an Agent-Based Model

PubMed Central

Mena, Carlos F.; Walsh, Stephen J.; Frizzelle, Brian G.; Xiaozheng, Yao; Malanson, George P.

2010-01-01

This paper describes the design and implementation of an Agent-Based Model (ABM) used to simulate land use change on household farms in the Northern Ecuadorian Amazon (NEA). The ABM simulates decision-making processes at the household level that is examined through a longitudinal, socio-economic and demographic survey that was conducted in 1990 and 1999. Geographic Information Systems (GIS) are used to establish spatial relationships between farms and their environment, while classified Landsat Thematic Mapper (TM) imagery is used to set initial land use/land cover conditions for the spatial simulation, assess from-to land use/land cover change patterns, and describe trajectories of land use change at the farm and landscape levels. Results from prior studies in the NEA provide insights into the key social and ecological variables, describe human behavioral functions, and examine population-environment interactions that are linked to deforestation and agricultural extensification, population migration, and demographic change. Within the architecture of the model, agents are classified as active or passive. The model comprises four modules, i.e., initialization, demography, agriculture, and migration that operate individually, but are linked through key household processes. The main outputs of the model include a spatially-explicit representation of the land use/land cover on survey and non-survey farms and at the landscape level for each annual time-step, as well as simulated socio-economic and demographic characteristics of households and communities. The work describes the design and implementation of the model and how population-environment interactions can be addressed in a frontier setting. The paper contributes to land change science by examining important pattern-process relations, advocating a spatial modeling approach that is capable of synthesizing fundamental relationships at the farm level, and links people and environment in complex ways. PMID:24436501

[Drug abuse in adolescent offenders: analysis of the psychosocial variables involved].

PubMed

Contreras Martínez, Lourdes; Molina Banqueri, Virginia; Cano Lozano, Ma Carmen

2012-01-01

Research shows that drugs and delinquency are frequently linked, the abuse of various types of substance being a widespread practice among young offenders. At the same time, some psychosocial characteristics are associated with both drug abuse and criminal/antisocial behavior. To help us explore the relationship between young offenders' drug abuse and certain psychosocial variables, we examined closed judicial files on young offenders from the Juvenile Justice Service in Jaen (Spain) corresponding to the period 2001 to 2010. From the contents of these judicial files we analyzed demographic variables such as gender and age, as well as psychosocial variables such as drug abuse, peer group, violent behavior, self-control, tolerance to frustration and attributional style. The results show that most of the young offenders use some type of drug, as well as revealing differential patterns of use according to gender. Also observed is a link between drug abuse and deviant peer group, violent behavior and the above-mentioned psychological variables. Finally, we found some differences in these psychological variables depending on the type of drug used.

Sliding mode observers for automotive alternator

NASA Astrophysics Data System (ADS)

Chen, De-Shiou

Estimator development for synchronous rectification of the automotive alternator is a desirable approach for estimating alternator's back electromotive forces (EMFs) without a direct mechanical sensor of the rotor position. Recent theoretical studies show that estimation of the back EMF may be observed based on system's phase current model by sensing electrical variables (AC phase currents and DC bus voltage) of the synchronous rectifier. Observer design of the back EMF estimation has been developed for constant engine speed. In this work, we are interested in nonlinear observer design of the back EMF estimation for the real case of variable engine speed. Initial back EMF estimate can be obtained from a first-order sliding mode observer (SMO) based on the phase current model. A fourth-order nonlinear asymptotic observer (NAO), complemented by the dynamics of the back EMF with time-varying frequency and amplitude, is then incorporated into the observer design for chattering reduction. Since the cost of required phase current sensors may be prohibitive, the most applicable approach in real implementation by measuring DC current of the synchronous rectifier is carried out in the dissertation. It is shown that the DC link current consists of sequential "windows" with partial information of the phase currents, hence, the cascaded NAO is responsible not only for the purpose of chattering reduction but also for necessarily accomplishing the process of estimation. Stability analyses of the proposed estimators are considered for most linear and time-varying cases. The stability of the NAO without speed information is substantiated by both numerical and experimental results. Prospective estimation algorithms for the case of battery current measurements are investigated. Theoretical study indicates that the convergence of the proposed LAO may be provided by high gain inputs. Since the order of the LAO/NAO for the battery current case is one order higher than that of the link current measurements, it is hard to find moderate values of the input gains for the real-time sampled-data systems. Technical difficulties in implementation of such high order discrete-time nonlinear estimators have been discussed. Directions of further investigations have been provided.

Mechanical behaviour׳s evolution of a PLA-b-PEG-b-PLA triblock copolymer during hydrolytic degradation.

PubMed

Breche, Q; Chagnon, G; Machado, G; Girard, E; Nottelet, B; Garric, X; Favier, D

2016-07-01

PLA-b-PEG-b-PLA is a biodegradable triblock copolymer that presents both the mechanical properties of PLA and the hydrophilicity of PEG. In this paper, physical and mechanical properties of PLA-b-PEG-b-PLA are studied during in vitro degradation. The degradation process leads to a mass loss, a decrease of number average molecular weight and an increase of dispersity index. Mechanical experiments are made in a specific experimental set-up designed to create an environment close to in vivo conditions. The viscoelastic behaviour of the material is studied during the degradation. Finally, the mechanical behaviour is modelled with a linear viscoelastic model. A degradation variable is defined and included in the model to describe the hydrolytic degradation. This variable is linked to physical parameters of the macromolecular polymer network. The model allows us to describe weak deformations but become less accurate for larger deformations. The abilities and limits of the model are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

High Capacity Communications From Martian Distances. Part 1; Spacecraft Link Design Analysis

NASA Technical Reports Server (NTRS)

Vyas, Hemali N.; Schuchman, Leonard; Orr, Richard; Williams, Wallace Dan; Collins, Michael; Noreen, Gary

2006-01-01

High capacity space communications has been a desire for Human Exploration and Science missions. Current Mars missions operate at data rates of 120 kbps for telemetry downlink and it is desirable to study high rate communication links in the range of 100 Mbps to 1 Gbps data rates from Martian distances. This paper will present some assumed scenarios along with link design assumptions and link analysis for high capacity communications from Mars. The paper will focus on RF subsystems namely antenna and power for the downlink communication from a relay orbiter at Mars. The relay orbiter will communicate with the low orbit spacecrafts at Mars or any Martian surface elements such as robots, and relay the data back to the ground networks on Earth. The study will dive into the spacecraft downlink system design and communication link analysis between the relay orbiter and ground network on Earth for data rates ranging from 100 Mbps to 1 Gbps based on the assumed scenarios and link assumptions. With high rate links at larger distances, there will be a significant impact on the antenna and power requirements and the link design will make an attempt to minimize the mass of the RF subsystem on the spacecraft. The results of this study will be presented for three data rates 1 Gbps, 500 Mbps and 100 Mbps at maximum Mars to Earth distance of 2.67AU. The design will use a Ka-band downlink with 90% link availability, along with various ground network G/T assumptions and possible bandwidth efficient modulations. The paper will conclude with what types of high rate communication links are feasible from Martian distances and also identify a range of requirements for antenna and power technologies for these high capacity communications from Mars.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smed, T.

Traditional eigenvalue sensitivity for power systems requires the formulation of the system matrix, which lacks sparsity. In this paper, a new sensitivity analysis, derived for a sparse formulation, is presented. Variables that are computed as intermediate results in established eigen value programs for power systems, but not used further, are given a new interpretation. The effect of virtually any control action can be assessed based on a single eigenvalue-eigenvector calculation. In particular, the effect of active and reactive power modulation can be found as a multiplication of two or three complex numbers. The method is illustrated in an example formore » a large power system when applied to the control design for an HVDC-link.« less

Comparison of open versus closed group interventions for sexually abused adolescent girls.

PubMed

Tourigny, Marc; Hébert, Martine

2007-01-01

A first aim of this study is to evaluate the efficacy of an open group therapy for sexually abused teenagers using a quasi-experimental pretest/posttest treatment design. A second aim was to explore whether differential gains were linked to an open versus a closed group format. Results indicate that sexually abused girls involved in an open group therapy showed significant gains relative to teenagers of the control group girls for the majority of the variables considered. Analyses contrasting the two formats of group therapy fail to identify statistical differences suggesting that both open and closed group formats are likely to be associated with the same significant gains for sexually abused teenagers.

Music training, cognition, and personality.

PubMed

Corrigall, Kathleen A; Schellenberg, E Glenn; Misura, Nicole M

2013-01-01

Although most studies that examined associations between music training and cognitive abilities had correlational designs, the prevailing bias is that music training causes improvements in cognition. It is also possible, however, that high-functioning children are more likely than other children to take music lessons, and that they also differ in personality. We asked whether individual differences in cognition and personality predict who takes music lessons and for how long. The participants were 118 adults (Study 1) and 167 10- to 12-year-old children (Study 2). We collected demographic information and measured cognitive ability and the Big Five personality dimensions. As in previous research, cognitive ability was associated with musical involvement even when demographic variables were controlled statistically. Novel findings indicated that personality was associated with musical involvement when demographics and cognitive ability were held constant, and that openness-to-experience was the personality dimension with the best predictive power. These findings reveal that: (1) individual differences influence who takes music lessons and for how long, (2) personality variables are at least as good as cognitive variables at predicting music training, and (3) future correlational studies of links between music training and non-musical ability should account for individual differences in personality.

Characterizing the nature and variability of avalanche hazard in western Canada

NASA Astrophysics Data System (ADS)

Shandro, Bret; Haegeli, Pascal

2018-04-01

The snow and avalanche climate types maritime, continental and transitional are well established and have been used extensively to characterize the general nature of avalanche hazard at a location, study inter-seasonal and large-scale spatial variabilities and provide context for the design of avalanche safety operations. While researchers and practitioners have an experience-based understanding of the avalanche hazard associated with the three climate types, no studies have described the hazard character of an avalanche climate in detail. Since the 2009/2010 winter, the consistent use of Statham et al. (2017) conceptual model of avalanche hazard in public avalanche bulletins in Canada has created a new quantitative record of avalanche hazard that offers novel opportunities for addressing this knowledge gap. We identified typical daily avalanche hazard situations using self-organizing maps (SOMs) and then calculated seasonal prevalence values of these situations. This approach produces a concise characterization that is conducive to statistical analyses, but still provides a comprehensive picture that is informative for avalanche risk management due to its link to avalanche problem types. Hazard situation prevalence values for individual seasons, elevations bands and forecast regions provide unprecedented insight into the inter-seasonal and spatial variability of avalanche hazard in western Canada.

Claims-based studies of oral glucose-lowering medications can achieve balance in critical clinical variables only observed in electronic health records.

PubMed

Patorno, Elisabetta; Gopalakrishnan, Chandrasekar; Franklin, Jessica M; Brodovicz, Kimberly G; Masso-Gonzalez, Elvira; Bartels, Dorothee B; Liu, Jun; Schneeweiss, Sebastian

2018-04-01

To evaluate the extent to which balance in unmeasured characteristics of patients with type 2 diabetes (T2DM) was achieved in claims data, by comparing against more detailed information from linked electronic health records (EHR) data. Within a large US commercial insurance database and using a cohort design, we identified patients with T2DM initiating linagliptin or a comparator agent within class (ie, another dipeptidyl peptidase-4 inhibitor) or outside class (ie, pioglitazone or a sulphonylurea) between May 2011 and December 2012. We focused on comparators used at a similar stage of diabetes to linagliptin. For each comparison, 1:1 propensity score (PS) matching was used to balance >100 baseline claims-based characteristics, including proxies of diabetes severity and duration. Additional clinical data from EHR were available for a subset of patients. We assessed representativeness of the claims-EHR-linked subset, evaluated the balance of claims- and EHR-based covariates before and after PS-matching via standardized differences (SDs), and quantified the potential bias associated with observed imbalances. From a claims-based study population of 166 613 patients with T2DM, 7219 (4.3%) patients were linked to their EHR data. Claims-based characteristics in the EHR-linked and EHR-unlinked patients were similar (SD < 0.1), confirming the representativeness of the EHR-linked subset. The balance of claims-based and EHR-based patient characteristics appeared to be reasonable before PS-matching and generally improved in the PS-matched population, to be SD < 0.1 for most patient characteristics and SD < 0.2 for select laboratory results and body mass index categories, which was not large enough to cause meaningful confounding. In the context of pharmacoepidemiological research on diabetes therapy, choosing appropriate comparison groups paired with a new-user design and 1:1 PS matching on many proxies of diabetes severity and duration improves balance in covariates typically unmeasured in administrative claims datasets, to the extent that residual confounding is unlikely. © 2017 John Wiley & Sons Ltd.

Serial killers with military experience: applying learning theory to serial murder.

PubMed

Castle, Tammy; Hensley, Christopher

2002-08-01

Scholars have endeavored to study the motivation and causality behind serial murder by researching biological, psychological, and sociological variables. Some of these studies have provided support for the relationship between these variables and serial murder. However, the study of serial murder continues to be an exploratory rather than explanatory research topic. This article examines the possible link between serial killers and military service. Citing previous research using social learning theory for the study of murder, this article explores how potential serial killers learn to reinforce violence, aggression, and murder in military boot camps. As with other variables considered in serial killer research, military experience alone cannot account for all cases of serial murder. Future research should continue to examine this possible link.

Work engagement supports nurse workforce stability and quality of care: nursing team-level analysis in psychiatric hospitals.

PubMed

Van Bogaert, P; Wouters, K; Willems, R; Mondelaers, M; Clarke, S

2013-10-01

Research in healthcare settings reveals important links between work environment factors, burnout and organizational outcomes. Recently, research focuses on work engagement, the opposite (positive) pole from burnout. The current study investigated the relationship of nurse practice environment aspects and work engagement (vigour, dedication and absorption) to job outcomes and nurse-reported quality of care variables within teams using a multilevel design in psychiatric inpatient settings. Validated survey instruments were used in a cross-sectional design. Team-level analyses were performed with staff members (n = 357) from 32 clinical units in two psychiatric hospitals in Belgium. Favourable nurse practice environment aspects were associated with work engagement dimensions, and in turn work engagement was associated with job satisfaction, intention to stay in the profession and favourable nurse-reported quality of care variables. The strongest multivariate models suggested that dedication predicted positive job outcomes whereas nurse management predicted perceptions of quality of care. In addition, reports of quality of care by the interdisciplinary team were predicted by dedication, absorption, nurse-physician relations and nurse management. The study findings suggest that differences in vigour, dedication and absorption across teams associated with practice environment characteristics impact nurse job satisfaction, intention to stay and perceptions of quality of care. © 2012 John Wiley & Sons Ltd.

Application of Buckingham π theorem for scaling-up oriented fast modelling of Proton Exchange Membrane Fuel Cell impedance

NASA Astrophysics Data System (ADS)

Russo, Luigi; Sorrentino, Marco; Polverino, Pierpaolo; Pianese, Cesare

2017-06-01

This work focuses on the development of a fast PEMFC impedance model, built starting from both physical and geometrical variables. Buckingham's π theorem is proposed to define non-dimensional parameters that allow suitably describing the relationships linking the physical variables involved in the process under-study to the fundamental dimensions. This approach is a useful solution for those problems, whose first principles-based models are not known, difficult to build or computationally unfeasible. The key contributions of the proposed similarity theory-based modelling approach are presented and discussed. The major advantage resides in its straightforward online applicability, thanks to very low computational burden, while preserving good level of accuracy. This makes the model suitable for several purposes, such as design, control, diagnostics, state of health monitoring and prognostics. Experimental data, collected in different operating conditions, have been analysed to demonstrate the capability of the model to reproduce PEMFC impedance at different loads and temperatures. This results in a reduction of the experimental effort for the FCS lab characterization. Moreover, it is highlighted the possibility to use the model with scaling-up purposes to reproduce the full stack impedance from single-cell one, thus supporting FC design and development from lab-to commercial system-scale.

Community demographics and the propensity to report animal cruelty.

PubMed

Taylor, Nicola; Signal, Tania D

2006-01-01

The last decade has seen an increased awareness concerning links between violence to nonhuman animals and violence to humans. This has resulted in a number of cross-reporting initiatives between family service providers and animal welfare organizations. The success of these initiatives rests on individuals being willing to report such violence. Thus, there is a need to determine which variables influence an individual's willingness to report deliberate animal cruelty and abuse. The aim of this study was to examine demographic and attitudinal variables to ascertain their impact on propensity to report deliberate animal harm. A telephone questionnaire resulted in 1,208 valid responses from members of the general community. Results showed a number of variables that affected the propensity to report: gender, occupation, and acknowledgment of the link between family violence and deliberate animal harm. This article discusses these variables and their implications.

Engine Power Turbine and Propulsion Pod Arrangement Study

NASA Technical Reports Server (NTRS)

Robuck, Mark; Zhang, Yiyi

2014-01-01

A study has been conducted for NASA Glenn Research Center under contract NNC10BA05B, Task NNC11TA80T to identify beneficial arrangements of the turboshaft engine, transmissions and related systems within the propulsion pod nacelle of NASA's Large Civil Tilt-Rotor 2nd iteration (LCTR2) vehicle. Propulsion pod layouts were used to investigate potential advantages, disadvantages, as well as constraints of various arrangements assuming front or aft shafted engines. Results from previous NASA LCTR2 propulsion system studies and tasks performed by Boeing under NASA contracts are used as the basis for this study. This configuration consists of two Fixed Geometry Variable Speed Power Turbine Engines and related drive and rotor systems (per nacelle) arranged in tilting nacelles near the wing tip. Entry-into-service (EIS) 2035 technology is assumed for both the engine and drive systems. The variable speed rotor system changes from 100 percent speed for hover to 54 percent speed for cruise by the means of a two speed gearbox concept developed under previous NASA contracts. Propulsion and drive system configurations that resulted in minimum vehicle gross weight were identified in previous work and used here. Results reported in this study illustrate that a forward shafted engine has a slight weight benefit over an aft shafted engine for the LCTR2 vehicle. Although the aft shafted engines provide a more controlled and centered CG (between hover and cruise), the length of the long rotor shaft and complicated engine exhaust arrangement outweighed the potential benefits. A Multi-Disciplinary Analysis and Optimization (MDAO) approach for transmission sizing was also explored for this study. This tool offers quick analysis of gear loads, bearing lives, efficiencies, etc., through use of commercially available RomaxDESIGNER software. The goal was to create quick methods to explore various concept models. The output results from RomaxDESIGNER have been successfully linked to Boeing spreadsheets that generate gear tooth geometry in Catia 3D environment. Another initial goal was to link information from RomaxDESIGNER (such as hp, rpm, gear ratio) to populate Boeing's parametric weight spreadsheet and create an automated method to estimate drive system weight. This was only partially achieved due to the variety of weight models, number of manual inputs, and qualitative assessments required. A simplified weight spreadsheet was used with data inputs from RomaxDESIGNER along with manual inputs to perform rough weight calculations.

Environmental links to interannual variability in shellfish toxicity in Cobscook Bay and eastern Maine, a strongly tidally mixed coastal region

NASA Astrophysics Data System (ADS)

Horecka, Hannah M.; Thomas, Andrew C.; Weatherbee, Ryan A.

2014-05-01

The Gulf of Maine experiences annual closures of shellfish harvesting due to the accumulation of toxins produced by dinoflagellates of the genus Alexandrium. Factors controlling the timing, location, and magnitude of these events in eastern Maine remain poorly understood. Previous work identified possible linkages between interannual variability of oceanographic variables and shellfish toxicity along the western Maine coastline but no such linkages were evident along the eastern Maine coast in the vicinity of Cobscook Bay, where strong tidal mixing tends to reduce seasonal variability in oceanographic properties. Using 21 years (1985-2005) of shellfish toxicity data, interannual variability in two metrics of annual toxicity, maximum magnitude and total annual toxicity, from stations in the Cobscook Bay region are examined for relationships to a suite of available environmental variables. Consistent with earlier work, no (or only weak) correlations were found between toxicity and oceanographic variables, even those very proximate to the stations such as local sea surface temperature. Similarly no correlations were evident between toxicity and air temperature, precipitation or relative humidity. The data suggest possible connections to local river discharge, but plausible mechanisms are not obvious. Correlations between toxicity and two variables indicative of local meteorological conditions, dew point and atmospheric pressure, both suggest a link between increased toxicity in these eastern Maine stations and weather conditions characterized by clearer skies/drier air (or less stormy/humid conditions). As no correlation of opposite sign was evident between toxicity and local precipitation, one plausible link is through light availability and its positive impact on phytoplankton production in this persistently foggy section of coast. These preliminary findings point to both the value of maintaining long-term shellfish toxicity sampling and a need for inclusion of weather variability in future modeling studies aimed at development of a more mechanistic understanding of factors controlling interannual differences in eastern Gulf of Maine shellfish toxicity.

Forced vs unforced drivers of Atlantic SST variability - linking forced role to magnitude of aerosol forcing

NASA Astrophysics Data System (ADS)

Booth, B.; Dunstone, N.; Halloran, P. R.; Andrews, T.; Bellouin, N.; Martin, E. R.

2014-12-01

Historical variations in North Atlantic SSTs have been a key driver of regional climate change - linked to drought frequency in the Sahel, Amazon and American Mid-West, rainfall and heat waves in Europe and frequency of Atlantic tropical storms. Traditionally these SST variations were deemed to arise from internally generated ocean variability. We present results from recent studies (Booth et al, 2012, Dunstone, 2013) that identify a mechanism via which volcanic and industrial aerosols could explain a large fraction of observed Atlantic variability, and its associated climate impacts. This work has prompted a lot of subsequent discussion about the relative contribution of ocean generated and external forced variability in the Atlantic. Here we present new results, that extend this earlier work, by looking at forced variability in the CMIP5 modelling context. This provides new insights into the potential externally forced role aerosols may play in the real world. CMIP5 models that represent aerosol-cloud interactions tend to have stronger correlations to observed variations in SSTs, but disagree on the magnitude of forced variability that they explain. We can link this contribution to the magnitude of aerosol forcing in each of these models - a factor that is both dependent on the aerosol parameterisation and the representation of boundary layer cloud in this region. This suggests that whether aerosols have played a larger or smaller role in historical Atlantic variability is tied to whether aerosols have a larger or smaller aerosol forcing (particularly indirect) in the real world. This in turn suggests that benefits of reducing current aerosol uncertainty are likely to extend beyond better estimates of global forcing, to providing a clearer picture of the past aerosol driven role in historical regional climate change.

The object of my aggression: Sexual objectification increases physical aggression toward women.

PubMed

Vasquez, Eduardo A; Ball, Louisa; Loughnan, Steve; Pina, Afroditi

2018-01-01

Objectification involves reducing someone to a sexual object, rather than seeing them as a full person. Despite numerous theoretical claims that people are more aggressive toward the objectified, and empirical evidence that objectification is linked to high willingness to aggress, rape proclivity, and aggressive attitudes, no research has examined a causal link between objectification and physical aggression, particularly in the context of provocation. In two experiments, we examined this predicted link. In Experiment 1, using a 2 (objectification: no/yes) × 2 (provocation: no/yes) factorial between-subjects design, we investigated the effects of objectification, induced via body focus during a face-to-face interaction, and provocation on physical aggression toward a female confederate. Our results revealed a significant main effect of provocation, a marginal main effect of objectification, and a significant interaction between these variables. In the absence of a provocation, focusing on a woman's body increased aggression toward her. Experiment 2 replicated Experiment 1 using a video of a target woman instead of a face-to-face interaction. Again, our results showed a significant two-way interaction between objectification and provocation, wherein objectification increased aggression in the absence of provocation. Overall, this research indicates that objectification can lead to heightened physical aggression toward objectified women. © 2017 Wiley Periodicals, Inc.

Determinants of choice for pigeons and humans on concurrent-chains schedules of reinforcement.

PubMed

Belke, T W; Pierce, W D; Powell, R A

1989-09-01

Concurrent-chains schedules of reinforcement were arranged for humans and pigeons. Responses of humans were reinforced with tokens exchangeable for money, and key pecks of 4 birds were reinforced with food. Variable-interval 30-s and 40-s schedules operated in the terminal links of the chains. Condition 1 exposed subjects to variable-interval 90-s and variable-interval 30-s initial links, respectively. Conditions 2 and 3 arranged equal initial-link schedules of 40 s or 120 s. Experimental conditions tested the descriptive adequacy of five equations: reinforcement density, delay reduction, modified delay reduction, matching and maximization. Results based on choice proportions and switch rates during the initial links showed that pigeons behaved in accord with delay-reduction models, whereas humans maximized overall rate of reinforcement. As discussed by Logue and associates in self-control research, different types of reinforcement may affect sensitivity to delay differentially. Pigeons' responses were reinforced with food, a reinforcer that is consumable upon presentation. Humans' responses were reinforced with money, a reinforcer exchanged for consumable reinforcers after it was earned. Reinforcers that are immediately consumed may generate high sensitivity to delay and behavior described as delay reduction. Reinforces with longer times to consumption may generate low sensitivity to delay and behavior that maximizes overall payoff.

Predicting preschoolers' social-cognitive play behavior: attachment, peers, temperament, and physiological regulation.

PubMed

Porter, Christin L

2009-04-01

Research on children's social-cognitive play typologies (i.e., active and passive forms of solitary and social play) suggests links of early play behaviors and later social development and risk status. To date, few studies have examined simultaneously suspected links between children's social-cognitive play types and factors believed to shape these early social-play behaviors. This study examined a simultaneous model of individual (temperament, physiology) and relational variables (attachment, peer networks) believed to influence children's social-cognitive play types, including individual characteristics drawn from the Child Behavior Questionnaire which measures dimensions of shyness and impulsivity, a lab-based assessment of social withdrawal, and physiological markers linked to social regulation (cardiac vagal tone and vagal regulation). Children's attachment status to parents was gathered using Q-Sort methodology, and a measure of previous peer network size was obtained from parents' reports to examine potential links between relational history and social-cognitive play types. Predictive discriminant function analysis showed that children's (N = 54, age range 35 to 58 months) social-cognitive play was better predicted on the basis of multiple independent variables than individual, zero-order relations. When predicting children's social-cognitive play typologies, a multidimensional view which encompasses both individual characteristics and social-relational variables may best predict social -cognitive play types and help understanding of children's social trajectories.

Elimination of deck joints using a corrosion resistant FRP approach

NASA Astrophysics Data System (ADS)

Aleti, Ashok Reddy

The research presented herein describes the development of durable link slabs for jointless bridge decks based on using FRP grid for reinforcement. Specifically, the ductility of the FRP material was utilized to accommodate bridge deck deformations imposed by girder deflection, temperature variations, and concrete shrinkage. It would also provide a solution to a number of deterioration problems associated with bridge deck joints. The design concept of the link slabs was then examined to form the basis of design for FRP grid link slabs. Improved design of FRP grid link slab/concrete deck slab interface was confirmed in the numerical analysis. The mechanical properties between the FRP grid and concrete were evaluated. The behavior of the link slab was investigated and confirmed for durability. The results indicated that the technique would allow simultaneous achievement of structural need (lower flexural stiffness of the link slab approaching the behavior of a hinge) and durability need of the link slab. Also, the development length results confirm that the bond between the FRP grid and the concrete was highly improved. The overall investigation supports the contention that durable jointless concrete bridge decks may be designed and constructed with FRP grid link slabs. It is recommended that the link slab technique be used during new construction of the bridge decks and in repair and retrofit of the bridge decks.

Developing Evidence & Gathering Data about Teacher Education Program Quality

ERIC Educational Resources Information Center

American Association of State Colleges and Universities, 2007

2007-01-01

Linking teacher practice to pupil outcomes has proven challenging for teacher educators. Methodological problems occur when linking individual teacher actions with subsequent pupil performance, including substantial intervening variables, questions about appropriate measures of student learning, issues regarding the lack of test standardization…

Characterization of the spatial variability of channel morphology

USGS Publications Warehouse

Moody, J.A.; Troutman, B.M.

2002-01-01

The spatial variability of two fundamental morphological variables is investigated for rivers having a wide range of discharge (five orders of magnitude). The variables, water-surface width and average depth, were measured at 58 to 888 equally spaced cross-sections in channel links (river reaches between major tributaries). These measurements provide data to characterize the two-dimensional structure of a channel link which is the fundamental unit of a channel network. The morphological variables have nearly log-normal probability distributions. A general relation was determined which relates the means of the log-transformed variables to the logarithm of discharge similar to previously published downstream hydraulic geometry relations. The spatial variability of the variables is described by two properties: (1) the coefficient of variation which was nearly constant (0.13-0.42) over a wide range of discharge; and (2) the integral length scale in the downstream direction which was approximately equal to one to two mean channel widths. The joint probability distribution of the morphological variables in the downstream direction was modelled as a first-order, bivariate autoregressive process. This model accounted for up to 76 per cent of the total variance. The two-dimensional morphological variables can be scaled such that the channel width-depth process is independent of discharge. The scaling properties will be valuable to modellers of both basin and channel dynamics. Published in 2002 John Wiley and Sons, Ltd.

Design and Optimization of a 3-Coil Inductive Link for Efficient Wireless Power Transmission.

PubMed

Kiani, Mehdi; Jow, Uei-Ming; Ghovanloo, Maysam

2011-07-14

Inductive power transmission is widely used to energize implantable microelectronic devices (IMDs), recharge batteries, and energy harvesters. Power transfer efficiency (PTE) and power delivered to the load (PDL) are two key parameters in wireless links, which affect the energy source specifications, heat dissipation, power transmission range, and interference with other devices. To improve the PTE, a 4-coil inductive link has been recently proposed. Through a comprehensive circuit based analysis that can guide a design and optimization scheme, we have shown that despite achieving high PTE at larger coil separations, the 4-coil inductive links fail to achieve a high PDL. Instead, we have proposed a 3-coil inductive power transfer link with comparable PTE over its 4-coil counterpart at large coupling distances, which can also achieve high PDL. We have also devised an iterative design methodology that provides the optimal coil geometries in a 3-coil inductive power transfer link. Design examples of 2-, 3-, and 4-coil inductive links have been presented, and optimized for 13.56 MHz carrier frequency and 12 cm coupling distance, showing PTEs of 15%, 37%, and 35%, respectively. At this distance, the PDL of the proposed 3-coil inductive link is 1.5 and 59 times higher than its equivalent 2- and 4-coil links, respectively. For short coupling distances, however, 2-coil links remain the optimal choice when a high PDL is required, while 4-coil links are preferred when the driver has large output resistance or small power is needed. These results have been verified through simulations and measurements.

The link between eddy-driven jet variability and weather regimes in the North Atlantic-European sector

NASA Astrophysics Data System (ADS)

Madonna, E.; Li, C.; Grams, C. M.; Woollings, T.

2017-12-01

Understanding the variability of the North Atlantic eddy-driven jet is key to unravelling the dynamics, predictability and climate change response of extratropical weather in the region. This study aims to 1) reconcile two perspectives on wintertime variability in the North Atlantic-European sector and 2) clarify their link to atmospheric blocking. Two common views of wintertime variability in the North Atlantic are the zonal-mean framework comprising three preferred locations of the eddy-driven jet (southern, central, northern), and the weather regime framework comprising four classical North Atlantic-European regimes (Atlantic ridge AR, zonal ZO, European/Scandinavian blocking BL, Greenland anticyclone GA). We use a k-means clustering algorithm to characterize the two-dimensional variability of the eddy-driven jet stream, defined by the lower tropospheric zonal wind in the ERA-Interim reanalysis. The first three clusters capture the central jet and northern jet, along with a new mixed jet configuration; a fourth cluster is needed to recover the southern jet. The mixed cluster represents a split or strongly tilted jet, neither of which is well described in the zonal-mean framework, and has a persistence of about one week, similar to the other clusters. Connections between the preferred jet locations and weather regimes are corroborated - southern to GA, central to ZO, and northern to AR. In addition, the new mixed cluster is found to be linked to European/Scandinavian blocking, whose relation to the eddy-driven jet was previously unclear. The results highlight the necessity of bridging from weather to climate scales for a deeper understanding of atmospheric circulation variability.

Improving the diagnosis related grouping model's ability to explain length of stay of elderly medical inpatients by incorporating function-linked variables.

PubMed

Sahadevan, S; Earnest, A; Koh, Y L; Lee, K M; Soh, C H; Ding, Y Y

2004-09-01

This study first aimed to determine the adequacy of the Diagnosis Related Grouping (DRG) model's ability to explain (1) the variance in the actual length of stay (LOS) of elderly medical inpatients and (2) the LOS difference in the same cohort between the departments of Geriatric Medicine (GRM) and General Medicine (GM). We then looked at how these explanatory abilities of the DRG changed when patients' function-linked variables (ignored by DRG) were incorporated into the model. Basic demographic data of a consecutively hospitalised cohort of elderly medical inpatients from GRM and GM, as well as their actual LOS, discharge DRG codes [with their corresponding trimmed average length of stay (ALOS)] and selected function-linked variables (including premorbid functional status, change in functional profile during hospitalisation and number of therapists seen) were recorded. Beginning with ALOS, function-linked variables that were significantly associated with LOS were then added into two multiple liner regression models so as to quantify how the functional dimension improved the DRGs' abilities to explain LOS variances and interdepartmental LOS differences. Forward selection procedure was employed to determine the final models. For the interdepartmental analysis, the study sample was restricted to patients who shared common DRG codes. 114 GRM and 118 GM patients were studied. Trimmed ALOS alone explained 8% of the actual LOS variance. With the addition of function-linked variables, the adjusted R2 of the final model increased to 28%. Due to common code restrictions, the data of 79 GRM and 78 GM patients were available for the analysis of interdepartmental LOS differences. At the unadjusted stage, the median stay of GRM patients was 4.3 days longer than GM's and with adjustments made for the DRGs, this difference was reduced to 3.9 days. Additionally adjusting for the patients' functional features diminished the interdepartmental LOS discrepancy even further, to 2.1 days. This study demonstrates that for elderly medical inpatients, the incorporation of patients' functional status significantly improves the DRG model's ability to predict the patients' actual LOS as well as to explain interdepartmental LOS differences between GRM and GM.

Assessing the Design and Development of Hybrid Linked Learning Professional Development Programs for Teachers: Challenges and Successes

ERIC Educational Resources Information Center

Erener, Eren

2017-01-01

This study informs instructional designers, all stakeholders in higher education and K-12, of the successes and challenges associated with designing and developing online/hybrid Linked Learning courses. The study examines via surveys and interviews the perspectives of instructional designers, subject matter experts, students, and course…

An improved strategy for regression of biophysical variables and Landsat ETM+ data.

Treesearch

Warren B. Cohen; Thomas K. Maiersperger; Stith T. Gower; David P. Turner

2003-01-01

Empirical models are important tools for relating field-measured biophysical variables to remote sensing data. Regression analysis has been a popular empirical method of linking these two types of data to provide continuous estimates for variables such as biomass, percent woody canopy cover, and leaf area index (LAI). Traditional methods of regression are not...

Variables Affecting Secondary School Students' Willingness to Eat Genetically Modified Food Crops

ERIC Educational Resources Information Center

Maes, Jasmien; Bourgonjon, Jeroen; Gheysen, Godelieve; Valcke, Martin

2018-01-01

A large-scale cross-sectional study (N = 4002) was set up to determine Flemish secondary school students' willingness to eat genetically modified food (WTE) and to link students' WTE to previously identified key variables from research on the acceptance of genetic modification (GM). These variables include subjective and objective knowledge about…

Detrital events and hydroclimate variability in the Romanian Carpathians during the mid-to-late Holocene

NASA Astrophysics Data System (ADS)

Longman, Jack; Ersek, Vasile; Veres, Daniel; Salzmann, Ulrich

2017-07-01

The Romanian Carpathians are located at the confluence of three major atmospheric pressure fields: the North Atlantic, the Mediterranean and the Siberian. Despite its importance for understanding past human impact and climate change, high-resolution palaeoenvironmental reconstructions of Holocene hydroclimate variability, and in particular records of extreme precipitation events in the area, are rare. Here we present a 7500-year-long high-resolution record of past climatic change and human impact recorded in a peatbog from the Southern Carpathians, integrating palynological, geochemical and sedimentological proxies. Natural climate fluctuations appear to be dominant until 4500 years before present (yr BP), followed by increasing importance of human impact. Sedimentological and geochemical analyses document regular minerogenic deposition within the bog, linked to periods of high precipitation. Such minerogenic depositional events began 4000 yr BP, with increased depositional rates during the Medieval Warm Period (MWP), the Little Ice Age (LIA) and during periods of societal upheaval (e.g. the Roman conquest of Dacia). The timing of minerogenic events appears to indicate a teleconnection between major shifts in North Atlantic Oscillation (NAO) and hydroclimate variability in southeastern Europe, with increased minerogenic deposition correlating to low NAO index values. By linking the minerogenic deposition to precipitation variability, we state that this link persists throughout the mid-to-late Holocene.

An Open Source modular platform for hydrological model implementation

NASA Astrophysics Data System (ADS)

Kolberg, Sjur; Bruland, Oddbjørn

2010-05-01

An implementation framework for setup and evaluation of spatio-temporal models is developed, forming a highly modularized distributed model system. The ENKI framework allows building space-time models for hydrological or other environmental purposes, from a suite of separately compiled subroutine modules. The approach makes it easy for students, researchers and other model developers to implement, exchange, and test single routines in a fixed framework. The open-source license and modular design of ENKI will also facilitate rapid dissemination of new methods to institutions engaged in operational hydropower forecasting or other water resource management. Written in C++, ENKI uses a plug-in structure to build a complete model from separately compiled subroutine implementations. These modules contain very little code apart from the core process simulation, and are compiled as dynamic-link libraries (dll). A narrow interface allows the main executable to recognise the number and type of the different variables in each routine. The framework then exposes these variables to the user within the proper context, ensuring that time series exist for input variables, initialisation for states, GIS data sets for static map data, manually or automatically calibrated values for parameters etc. ENKI is designed to meet three different levels of involvement in model construction: • Model application: Running and evaluating a given model. Regional calibration against arbitrary data using a rich suite of objective functions, including likelihood and Bayesian estimation. Uncertainty analysis directed towards input or parameter uncertainty. o Need not: Know the model's composition of subroutines, or the internal variables in the model, or the creation of method modules. • Model analysis: Link together different process methods, including parallel setup of alternative methods for solving the same task. Investigate the effect of different spatial discretization schemes. o Need not: Write or compile computer code, handle file IO for each modules, • Routine implementation and testing. Implementation of new process-simulating methods/equations, specialised objective functions or quality control routines, testing of these in an existing framework. o Need not: Implement user or model interface for the new routine, IO handling, administration of model setup and run, calibration and validation routines etc. From being developed for Norway's largest hydropower producer Statkraft, ENKI is now being turned into an Open Source project. At the time of writing, the licence and the project administration is not established. Also, it remains to port the application to other compilers and computer platforms. However, we hope that ENKI will prove useful for both academic and operational users.

Weather related continuity and completeness on Deep Space Ka-band links: statistics and forecasting

NASA Technical Reports Server (NTRS)

Shambayati, Shervin

2006-01-01

In this paper the concept of link 'stability' as means of measuring the continuity of the link is introduced and through it, along with the distributions of 'good' periods and 'bad' periods, the performance of the proposed Ka-band link design method using both forecasting and long-term statistics has been analyzed. The results indicate that the proposed link design method has relatively good continuity and completeness characteristics even when only long-term statistics are used and that the continuity performance further improves when forecasting is employed. .

Equipment Management for Sensor Networks: Linking Physical Infrastructure and Actions to Observational Data

NASA Astrophysics Data System (ADS)

Jones, A. S.; Horsburgh, J. S.; Matos, M.; Caraballo, J.

2015-12-01

Networks conducting long term monitoring using in situ sensors need the functionality to track physical equipment as well as deployments, calibrations, and other actions related to site and equipment maintenance. The observational data being generated by sensors are enhanced if direct linkages to equipment details and actions can be made. This type of information is typically recorded in field notebooks or in static files, which are rarely linked to observations in a way that could be used to interpret results. However, the record of field activities is often relevant to analysis or post-processing of the observational data. We have developed an underlying database schema and deployed a web interface for recording and retrieving information on physical infrastructure and related actions for observational networks. The database schema for equipment was designed as an extension to the Observations Data Model 2 (ODM2), a community-developed information model for spatially discrete, feature based earth observations. The core entities of ODM2 describe location, observed variable, and timing of observations, and the equipment extension contains entities to provide additional metadata specific to the inventory of physical infrastructure and associated actions. The schema is implemented in a relational database system for storage and management with an associated web interface. We designed the web-based tools for technicians to enter and query information on the physical equipment and actions such as site visits, equipment deployments, maintenance, and calibrations. These tools were implemented for the iUTAH (innovative Urban Transitions and Aridregion Hydrosustainability) ecohydrologic observatory, and we anticipate that they will be useful for similar large-scale monitoring networks desiring to link observing infrastructure to observational data to increase the quality of sensor-based data products.

Effect of marijuana use on cardiovascular and cerebrovascular mortality: A study using the National Health and Nutrition Examination Survey linked mortality file.

PubMed

Yankey, Barbara A; Rothenberg, Richard; Strasser, Sheryl; Ramsey-White, Kim; Okosun, Ike S

2017-11-01

Background Reports associate marijuana use with cardiovascular emergencies. Studies relating marijuana use to cardiovascular mortality are scarce. Recent advance towards marijuana use legalization emphasizes the importance of understanding relationships between marijuana use and cardiovascular deaths; the primary ranked mortality. Recreational marijuana is primarily smoked; we hypothesize that like cigarette smoking, marijuana use will be associated with increased cardiovascular mortalities. Design The design of this study was based on a mortality follow-up. Method We linked participants aged 20 years and above, who responded to questions on marijuana use during the 2005 US National Health and Nutrition Examination Survey to data from the 2011 public-use linked mortality file of the National Center for Health Statistics, Centers for Disease Control and Prevention. Only participants eligible for mortality follow-up were included. We conducted Cox proportional hazards regression analyses to estimate hazard ratios for hypertension, heart disease, and cerebrovascular mortality due to marijuana use. We controlled for cigarette smoking and other relevant variables. Results Of the 1213 eligible participants 72.5% were presumed to be alive. The total follow-up time was 19,569 person-years. Adjusted hazard ratios for death from hypertension among marijuana users compared to non-marijuana users was 3.42 (95% confidence interval: 1.20-9.79) and for each year of marijuana use was 1.04 (95% confidence interval: 1.00-1.07). Conclusion From our results, marijuana use may increase the risk for hypertension mortality. Increased duration of marijuana use is associated with increased risk of death from hypertension. Recreational marijuana use potentially has cardiovascular adverse effects which needs further investigation.

Investigating Environmental Links between Parent Depression and Child Depressive/Anxiety Symptoms Using an Assisted Conception Design

ERIC Educational Resources Information Center

Lewis, Gemma; Rice, Frances; Harold, Gordon T.; Collishaw, Stephan; Thapar, Anita

2011-01-01

Objective: Links between maternal and offspring depression symptoms could arise from inherited factors, direct environmental exposure, or shared adversity. A novel genetically sensitive design was used to test the extent of environmental links between maternal depression symptoms and child depression/anxiety symptoms, accounting for inherited…

Learning by Example: Designing and Developing Linked Data Application

ERIC Educational Resources Information Center

Tharani, Karim

2016-01-01

According to constructivist theory of learning, new knowledge is learned on the basis of what is already known by learners. Thus for an emerging and transformative technology such as Linked Data to be learned, the technology must be made relevant for learners and must be compatible with their skillset. Designing and developing Linked Data…

Gathering Empirical Evidence Concerning Links between Computer Aided Design (CAD) and Creativity

ERIC Educational Resources Information Center

Musta'amal, Aede Hatib; Norman, Eddie; Hodgson, Tony

2009-01-01

Discussion is often reported concerning potential links between computer-aided designing and creativity, but there is a lack of systematic enquiry to gather empirical evidence concerning such links. This paper reports an indication of findings from other research studies carried out in contexts beyond general education that have sought evidence…

A Novel Concept for Safe, Stiffness-Controllable Robot Links.

PubMed

Stilli, Agostino; Wurdemann, Helge A; Althoefer, Kaspar

2017-03-01

The recent decade has seen an astounding increase of interest and advancement in a new field of robotics, aimed at creating structures specifically for the safe interaction with humans. Softness, flexibility, and variable stiffness in robotics have been recognized as highly desirable characteristics for many applications. A number of solutions were proposed ranging from entirely soft robots (such as those composed mainly from soft materials such as silicone), via flexible continuum and snake-like robots, to rigid-link robots enhanced by joints that exhibit an elastic behavior either implemented in hardware or achieved purely by means of intelligent control. Although these are very good solutions paving the path to safe human-robot interaction, we propose here a new approach that focuses on creating stiffness controllability for the linkages between the robot joints. This article proposes a replacement for the traditionally rigid robot link-the new link is equipped with an additional capability of stiffness controllability. With this added feature, a robot can accurately carry out manipulation tasks (high stiffness), but can virtually instantaneously reduce its stiffness when a human is nearby or in contact with the robot. The key point of the invention described here is a robot link made of an airtight chamber formed by a soft and flexible, but high-strain resistant combination of a plastic mesh and silicone wall. Inflated with air to a high pressure, the mesh silicone chamber behaves like a rigid link; reducing the air pressure, softens the link and rendering the robot structure safe. This article investigates a number of link prototypes and shows the feasibility of the new concept. Stiffness tests have been performed, showing that a significant level of stiffness can be achieved-up to 40 N reaction force along the axial direction, for a 25-mm-diameter sample at 60 kPa, at an axial deformation of 5 mm. The results confirm that this novel concept to linkages for robot manipulators exhibits the beam-like behavior of traditional rigid links when fully pressurized and significantly reduced stiffness at low pressure. The proposed concept has the potential to easily create safe robots, augmenting traditional robot designs.

Demographic factors, fatigue, and driving accidents: An examination of the published literature.

PubMed

Di Milia, Lee; Smolensky, Michael H; Costa, Giovanni; Howarth, Heidi D; Ohayon, Maurice M; Philip, Pierre

2011-03-01

This article reviews the literature pertaining to the association between demographic variables (e.g., age, sex, race, socio-economic status) with fatigue, and when feasible, accident risk. It also explores their potential influence and interaction with some working arrangements, commute time, personality characteristics, and circadian chronotype. Fatigue has been implicated in a range of impairments that can have detrimental effects on individuals, and it is differentially associated with conventional demographic variables. However, several major methodological limitations prevent clear conclusions. First, there is absence of a shared definition both within and across disciplines. Second, although fatigue has been investigated using a variety of diverse designs, they have either been too weak to substantiate causality or lacked ecological validity. Third, while both subjective and objective measures have been used as dependent variables, fatigue has been more often found to be more strongly linked with the former. Fourth, with the exception of age and sex, the influence of other demographic variables is unknown, since they have not yet been concomitantly assessed. In instances when they have been assessed and included in statistical analyses, they are considered as covariates or confounders; thus, their contribution to the outcome variable is controlled for, rather than being a planned aspect of investigation. Because the interaction of demographic factors with fatigue is largely a neglected area of study, we recommend greater interdisciplinary collaborations, incorporation of multiple demographic variables as independent factors, and use of within-participant analyses. These recommendations would provide meaningful results that may be used to inform public policy and preventive strategies. Copyright © 2009 Elsevier Ltd. All rights reserved.

Marine reserves as linked social-ecological systems.

PubMed

Pollnac, Richard; Christie, Patrick; Cinner, Joshua E; Dalton, Tracey; Daw, Tim M; Forrester, Graham E; Graham, Nicholas A J; McClanahan, Timothy R

2010-10-26

Marine reserves are increasingly recognized as having linked social and ecological dynamics. This study investigates how the ecological performance of 56 marine reserves throughout the Philippines, Caribbean, and Western Indian Ocean (WIO) is related to both reserve design features and the socioeconomic characteristics in associated coastal communities. Ecological performance was measured as fish biomass in the reserve relative to nearby areas. Of the socioeconomic variables considered, human population density and compliance with reserve rules had the strongest effects on fish biomass, but the effects of these variables were region specific. Relationships between population density and the reserve effect on fish biomass were negative in the Caribbean, positive in the WIO, and not detectable in the Philippines. Differing associations between population density and reserve effectiveness defy simple explanation but may depend on human migration to effective reserves, depletion of fish stocks outside reserves, or other social factors that change with population density. Higher levels of compliance reported by resource users was related to higher fish biomass in reserves compared with outside, but this relationship was only statistically significant in the Caribbean. A heuristic model based on correlations between social, cultural, political, economic, and other contextual conditions in 127 marine reserves showed that high levels of compliance with reserve rules were related to complex social interactions rather than simply to enforcement of reserve rules. Comparative research of this type is important for uncovering the complexities surrounding human dimensions of marine reserves and improving reserve management.

School and residential neighborhood food environment and diet among California youth.

PubMed

An, Ruopeng; Sturm, Roland

2012-02-01

Various hypotheses link neighborhood food environments and diet. Greater exposure to fast-food restaurants and convenience stores is thought to encourage overconsumption; supermarkets and large grocery stores are claimed to encourage healthier diets. For youth, empirical evidence for any particular hypothesis remains limited. This study examines the relationship between school and residential neighborhood food environment and diet among youth in California. Data from 8226 children (aged 5-11 years) and 5236 adolescents (aged 12-17 years) from the 2005 and 2007 California Health Interview Survey were analyzed in 2011. The dependent variables are daily servings of fruits, vegetables, juice, milk, soda, high-sugar foods, and fast food, which were regressed on measures of food environments. Food environments were measured by counts and density of businesses, distinguishing fast-food restaurants, convenience stores, small food stores, grocery stores, and large supermarkets within a specific distance (varying from 0.1 to 1.5 miles) from a respondent's home or school. No robust relationship between food environment and consumption is found. A few significant results are sensitive to small modeling changes and more likely to reflect chance than true relationships. This correlational study has measurement and design limitations. Longitudinal studies that can assess links between environmental, dependent, and intervening food purchase and consumption variables are needed. Reporting a full range of studies, methods, and results is important as a premature focus on correlations may lead policy astray. Copyright © 2012 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Using multi-disciplinary strategic master facilities planning for organizations experiencing programmatic re-direction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heubach, J.G.; Weimer, W.C.; Bruce, W.A.

Facility master planning is critical to the future productivity of a laboratory and the quality of worklife for the laboratory staff. For organizations undergoing programmatic re-direction, a master facility planning approach linked to the organization`s strategic planning process is even more important. Major changes in an organization such as programmatic re-direction can significantly impact a broad range of variables which exceed the expertise of traditional planning teams, e.g., capacity variability, work team organization, organizational culture, and work process simplification. By expanding the diversity of the participants of the planning team, there is a greater likelihood that a research organization`s scientific,more » organizational, economic, and employees` needs can be meshed in the strategic plan and facility plan. Recent recommendations from facility planners suggest drawing from diverse fields in building multi-disciplinary planning teams: Architecture, engineering, natural science, social psychology, and strategic planning (Gibson,1993). For organizations undergoing significant operational or culture change, the master facility planning team should also include members with expertise in organizational effectiveness, industrial engineering, human resources, and environmental psychology. A recent planning and design project provides an example which illustrates the use of an expanded multi-disciplinary team engaged in planning laboratory renovations for a research organization undergoing programmatic re-direction. The purpose of the proposed poster session is to present a multi-disciplinary master facility planning process linked to an organization`s strategic planning process or organizational strategies.« less

Exploring the Climate Change, Migration and Conflict Nexus.

PubMed

Burrows, Kate; Kinney, Patrick L

2016-04-22

The potential link between climate change, migration, and conflict has been widely discussed and is increasingly viewed by policy makers as a security issue. However, considerable uncertainty remains regarding the role that climate variability and change play among the many drivers of migration and conflict. The overall objective of this paper is to explore the potential pathways linking climate change, migration and increased risk of conflict. We review the existing literature surrounding this issue and break the problem into two components: the links between climate change and migration, and those between migration and conflict. We found a large range of views regarding the importance of climate change as a driver for increasing rates of migration and subsequently of conflict. We argue that future research should focus not only on the climate-migration-conflict pathway but also work to understand the other pathways by which climate variability and change might exacerbate conflict. We conclude by proposing five questions to help guide future research on the link between climate change, migration, and conflict.

Exploring the Climate Change, Migration and Conflict Nexus

PubMed Central

Burrows, Kate; Kinney, Patrick L.

2016-01-01

The potential link between climate change, migration, and conflict has been widely discussed and is increasingly viewed by policy makers as a security issue. However, considerable uncertainty remains regarding the role that climate variability and change play among the many drivers of migration and conflict. The overall objective of this paper is to explore the potential pathways linking climate change, migration and increased risk of conflict. We review the existing literature surrounding this issue and break the problem into two components: the links between climate change and migration, and those between migration and conflict. We found a large range of views regarding the importance of climate change as a driver for increasing rates of migration and subsequently of conflict. We argue that future research should focus not only on the climate-migration-conflict pathway but also work to understand the other pathways by which climate variability and change might exacerbate conflict. We conclude by proposing five questions to help guide future research on the link between climate change, migration, and conflict. PMID:27110806

The Project TALENT Twin and Sibling Study.

PubMed

Prescott, Carol A; Achorn, Deanna Lyter; Kaiser, Ashley; Mitchell, Lindsey; McArdle, John J; Lapham, Susan J

2013-02-01

Project TALENT is a US national longitudinal study of about 377,000 individuals born in 1942-1946, first assessed in 1960. Students in about 1,200 schools participated in a 2-day battery covering aptitudes, abilities, interests, and individual and family characteristics (Flanagan, 1962; www.projectTALENT.org). Follow-up assessments 1, 5, and 11 years later assessed educational and occupational outcomes. The sample includes approximately 92,000 siblings from 40,000 families, including 2,500 twin pairs and 1,200 other siblings of twins. Until recently, almost no behavior genetic research has been conducted with the sample. In the original data collection information was not collected with the intent to link family members. Recently, we developed algorithms using names, addresses, birthdates, and information about family structure to link siblings and identify twins. We are testing several methods to determine zygosity, including use of yearbook photographs. In this paper, we summarize the design and measures in Project TALENT, describe the Twin and Sibling sample, and present our twin-sib-classmate model. In most twin and family designs, the 'shared environment' includes factors specific to the family combined with between-family differences associated with macro-level variables such as socioeconomic status. The school-based sampling design used in Project TALENT provides a unique opportunity to partition the shared environment into variation shared by siblings, specific to twins, and associated with school- and community-level factors. The availability of many measured characteristics on the family, schools, and neighborhoods enhances the ability to study the impact of specific factors on behavioral variation.

The Role of Margin in Link Design and Optimization

NASA Technical Reports Server (NTRS)

Cheung, K.

2015-01-01

Link analysis is a system engineering process in the design, development, and operation of communication systems and networks. Link models that are mathematical abstractions representing the useful signal power and the undesirable noise and attenuation effects (including weather effects if the signal path transverses through the atmosphere) that are integrated into the link budget calculation that provides the estimates of signal power and noise power at the receiver. Then the link margin is applied which attempts to counteract the fluctuations of the signal and noise power to ensure reliable data delivery from transmitter to receiver. (Link margin is dictated by the link margin policy or requirements.) A simple link budgeting approach assumes link parameters to be deterministic values typically adopted a rule-of-thumb policy of 3 dB link margin. This policy works for most S- and X-band links due to their insensitivity to weather effects. But for higher frequency links like Ka-band, Ku-band, and optical communication links, it is unclear if a 3 dB link margin would guarantee link closure. Statistical link analysis that adopted the 2-sigma or 3-sigma link margin incorporates link uncertainties in the sigma calculation. (The Deep Space Network (DSN) link margin policies are 2-sigma for downlink and 3-sigma for uplink.) The link reliability can therefore be quantified statistically even for higher frequency links. However in the current statistical link analysis approach, link reliability is only expressed as the likelihood of exceeding the signal-to-noise ratio (SNR) threshold that corresponds to a given bit-error-rate (BER) or frame-error-rate (FER) requirement. The method does not provide the true BER or FER estimate of the link with margin, or the required signalto-noise ratio (SNR) that would meet the BER or FER requirement in the statistical sense. In this paper, we perform in-depth analysis on the relationship between BER/FER requirement, operating SNR, and coding performance curve, in the case when the channel coherence time of link fluctuation is comparable or larger than the time duration of a codeword. We compute the "true" SNR design point that would meet the BER/FER requirement by taking into account the fluctuation of signal power and noise power at the receiver, and the shape of the coding performance curve. This analysis yields a number of valuable insights on the design choices of coding scheme and link margin for the reliable data delivery of a communication system - space and ground. We illustrate the aforementioned analysis using a number of standard NASA error-correcting codes.

Controller evaluation of initial data link en route air traffic control services : ISSS design development : study 1

DOT National Transportation Integrated Search

1994-05-01

This report documents the first Federal Aviation Administration (FAA) design : development study of an initial group of en route air traffic control (ATC) : services designed for transmission by Data Link technologies using the Initial : Sector Suite...

Workplace support, discrimination, and person-organization fit: tests of the theory of work adjustment with LGB individuals.

PubMed

Velez, Brandon L; Moradi, Bonnie

2012-07-01

The present study explored the links of 2 workplace contextual variables--perceptions of workplace heterosexist discrimination and lesbian, gay, and bisexual (LGB)-supportive climates--with job satisfaction and turnover intentions in a sample of LGB employees. An extension of the theory of work adjustment (TWA) was used as the conceptual framework for the study; as such, perceived person-organization (P-O) fit was tested as a mediator of the relations between the workplace contextual variables and job outcomes. Data were analyzed from 326 LGB employees. Zero-order correlations indicated that perceptions of workplace heterosexist discrimination and LGB-supportive climates were correlated in expected directions with P-O fit, job satisfaction, and turnover intentions. Structural equation modeling (SEM) was used to compare multiple alternative measurement models evaluating the discriminant validity of the 2 workplace contextual variables relative to one another, and the 3 TWA job variables relative to one another; SEM was also used to test the hypothesized mediation model. Comparisons of multiple alternative measurement models supported the construct distinctiveness of the variables of interest. The test of the hypothesized structural model revealed that only LGB-supportive climates (and not workplace heterosexist discrimination) had a unique direct positive link with P-O fit and, through the mediating role of P-O fit, had significant indirect positive and negative relations with job satisfaction and turnover intentions, respectively. Moreover, P-O fit had a significant indirect negative link with turnover intentions through job satisfaction.

A Linked Fusion of Things, Services, and Data to Support a Collaborative Data Management Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stephan, Eric G.; Elsethagen, Todd O.; Wynne, Adam S.

The purpose of this paper is to illustrate the use of semantic technologies and approaches to seamlessly link things, services, and data in the proposed design of a scientific offshore wind energy research for the U.S. Department of Energy Wind and Water Technology Office of the Office of Energy Efficiency and Renewable Energy (EERE). By adapting linked community best practices, we were able to design a collaborative facility supporting both operational staff and end users that incorporates off-the-shelf components and overcome traditional barriers between devices, resulting data, and processing services. This was made largely possible through complementary advances in themore » Internet of Things (IoT), semantic web, Linked Services, and Linked Data communities, which provide the foundation for our design.« less

Development of a real-time PCR method for the differential detection and quantification of four solanaceae in GMO analysis: potato (Solanum tuberosum), tomato (Solanum lycopersicum), eggplant (Solanum melongena), and pepper (Capsicum annuum).

PubMed

Chaouachi, Maher; El Malki, Redouane; Berard, Aurélie; Romaniuk, Marcel; Laval, Valérie; Brunel, Dominique; Bertheau, Yves

2008-03-26

The labeling of products containing genetically modified organisms (GMO) is linked to their quantification since a threshold for the presence of fortuitous GMOs in food has been established. This threshold is calculated from a combination of two absolute quantification values: one for the specific GMO target and the second for an endogenous reference gene specific to the taxon. Thus, the development of reliable methods to quantify GMOs using endogenous reference genes in complex matrixes such as food and feed is needed. Plant identification can be difficult in the case of closely related taxa, which moreover are subject to introgression events. Based on the homology of beta-fructosidase sequences obtained from public databases, two couples of consensus primers were designed for the detection, quantification, and differentiation of four Solanaceae: potato (Solanum tuberosum), tomato (Solanum lycopersicum), pepper (Capsicum annuum), and eggplant (Solanum melongena). Sequence variability was studied first using lines and cultivars (intraspecies sequence variability), then using taxa involved in gene introgressions, and finally, using taxonomically close taxa (interspecies sequence variability). This study allowed us to design four highly specific TaqMan-MGB probes. A duplex real time PCR assay was developed for simultaneous quantification of tomato and potato. For eggplant and pepper, only simplex real time PCR tests were developed. The results demonstrated the high specificity and sensitivity of the assays. We therefore conclude that beta-fructosidase can be used as an endogenous reference gene for GMO analysis.

Design of a video teleconference facility for a synchronous satellite communications link

NASA Technical Reports Server (NTRS)

Richardson, M. D.

1979-01-01

The system requirements, design tradeoffs, and final design of a video teleconference facility are discussed, including proper lighting, graphics transmission, and picture aesthetics. Methods currently accepted in the television broadcast industry are used in the design. The unique problems associated with using an audio channel with a synchronous satellite communications link are discussed, and a final audio system design is presented.

Data preparation techniques for a perinatal psychiatric study based on linked data.

PubMed

Xu, Fenglian; Hilder, Lisa; Austin, Marie-Paule; Sullivan, Elizabeth A

2012-06-08

In recent years there has been an increase in the use of population-based linked data. However, there is little literature that describes the method of linked data preparation. This paper describes the method for merging data, calculating the statistical variable (SV), recoding psychiatric diagnoses and summarizing hospital admissions for a perinatal psychiatric study. The data preparation techniques described in this paper are based on linked birth data from the New South Wales (NSW) Midwives Data Collection (MDC), the Register of Congenital Conditions (RCC), the Admitted Patient Data Collection (APDC) and the Pharmaceutical Drugs of Addiction System (PHDAS). The master dataset is the meaningfully linked data which include all or major study data collections. The master dataset can be used to improve the data quality, calculate the SV and can be tailored for different analyses. To identify hospital admissions in the periods before pregnancy, during pregnancy and after birth, a statistical variable of time interval (SVTI) needs to be calculated. The methods and SPSS syntax for building a master dataset, calculating the SVTI, recoding the principal diagnoses of mental illness and summarizing hospital admissions are described. Linked data preparation, including building the master dataset and calculating the SV, can improve data quality and enhance data function.

Progressive segmented health insurance: Colombian health reform and access to health services.

PubMed

Ruiz, Fernando; Amaya, Liliana; Venegas, Stella

2007-01-01

Equal access for poor populations to health services is a comprehensive objective for any health reform. The Colombian health reform addressed this issue through a segmented progressive social health insurance approach. The strategy was to assure universal coverage expanding the population covered through payroll linked insurance, and implementing a subsidized insurance program for the poorest populations, those not affiliated through formal employment. A prospective study was performed to follow-up health service utilization and out-of-pocket expenses using a cohort design. It was representative of four Colombian cities (Cendex Health Services Use and Expenditure Study, 2001). A four part econometric model was applied. The model related medical service utilization and medication with different socioeconomic, geographic, and risk associated variables. Results showed that subsidized health insurance improves health service utilization and reduces the financial burden for the poorest, as compared to those non-insured. Other social health insurance schemes preserved high utilization with variable out-of-pocket expenditures. Family and age conditions have significant effect on medical service utilization. Geographic variables play a significant role in hospital inpatient service utilization. Both, geographic and income variables also have significant impact on out-of-pocket expenses. Projected utilization rates and a simulation favor a dual policy for two-stage income segmented insurance to progress towards the universal insurance goal. Copyright (c) 2006 John Wiley & Sons, Ltd.

Glocal clinical registries: pacemaker registry design and implementation for global and local integration--methodology and case study.

PubMed

da Silva, Kátia Regina; Costa, Roberto; Crevelari, Elizabeth Sartori; Lacerda, Marianna Sobral; de Moraes Albertini, Caio Marcos; Filho, Martino Martinelli; Santana, José Eduardo; Vissoci, João Ricardo Nickenig; Pietrobon, Ricardo; Barros, Jacson V

2013-01-01

The ability to apply standard and interoperable solutions for implementing and managing medical registries as well as aggregate, reproduce, and access data sets from legacy formats and platforms to advanced standard formats and operating systems are crucial for both clinical healthcare and biomedical research settings. Our study describes a reproducible, highly scalable, standard framework for a device registry implementation addressing both local data quality components and global linking problems. We developed a device registry framework involving the following steps: (1) Data standards definition and representation of the research workflow, (2) Development of electronic case report forms using REDCap (Research Electronic Data Capture), (3) Data collection according to the clinical research workflow and, (4) Data augmentation by enriching the registry database with local electronic health records, governmental database and linked open data collections, (5) Data quality control and (6) Data dissemination through the registry Web site. Our registry adopted all applicable standardized data elements proposed by American College Cardiology / American Heart Association Clinical Data Standards, as well as variables derived from cardiac devices randomized trials and Clinical Data Interchange Standards Consortium. Local interoperability was performed between REDCap and data derived from Electronic Health Record system. The original data set was also augmented by incorporating the reimbursed values paid by the Brazilian government during a hospitalization for pacemaker implantation. By linking our registry to the open data collection repository Linked Clinical Trials (LinkedCT) we found 130 clinical trials which are potentially correlated with our pacemaker registry. This study demonstrates how standard and reproducible solutions can be applied in the implementation of medical registries to constitute a re-usable framework. Such approach has the potential to facilitate data integration between healthcare and research settings, also being a useful framework to be used in other biomedical registries.

The Effect of Differential Motivation on IRT Linking

ERIC Educational Resources Information Center

Mittelhaëuser, Marie-Anne; Béguin, Anton A.; Sijtsma, Klaas

2015-01-01

The purpose of this study was to investigate whether simulated differential motivation between the stakes for operational tests and anchor items produces an invalid linking result if the Rasch model is used to link the operational tests. This was done for an external anchor design and a variation of a pretest design. The study also investigated…

78 FR 22620 - Additional Designations, Foreign Narcotics Kingpin Designation Act

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-16

...''), Col Bella Vista, Casa No. 09, Camino a Rotulo de Coca Cola, San Pedro Sula, Cortes, Honduras; DOB 14...] (Linked To: AUTO PARTES HANDAL S. DE R.L. DE C.V.; Linked To: RANCHO LA HERRADURA; Linked To: SUPERTIENDAS..., La Ceiba, Atlantida, Honduras; Ave Junior, Entre 7 y 6 Calle Sureste, San Pedero Sula, Cortes...

Control, communication and monitoring of intravaginal drug delivery in dairy cows.

PubMed

Cross, Peter S; Künnemeyer, Rainer; Bunt, Craig R; Carnegie, Dale A; Rathbone, Michael J

2004-09-10

We present the design of an electronically controlled drug delivery system. The intravaginally located device is a low-invasive platform that can measure and react inside the cow vagina while providing external control and monitoring ability. The electronics manufactured from off the shelf components occupies 16 mL of a Theratron syringe. A microcontroller reads and logs sensor data and controls a gascell. The generated gas pressure propels the syringe piston and releases the formulation. A two way radio link allows communication between other devices or a base station. Proof of principle experiments confirm variable-rate, arbitrary profile drug delivery qualified by internal sensors. A total volume of 30 mL was dispensed over a 7-day-period with a volume error of +/- 1 mL or +/- 7% for larger volumes. Delivery was controlled or overridden via the wireless link, and proximity to other devices was detected and recorded. The results suggest that temperature and activity sensing or social grouping determined via proximity can be used to detect oestrus and trigger appropriate responses.

Bias and Bias Correction in Multisite Instrumental Variables Analysis of Heterogeneous Mediator Effects

ERIC Educational Resources Information Center

Reardon, Sean F.; Unlu, Fatih; Zhu, Pei; Bloom, Howard S.

2014-01-01

We explore the use of instrumental variables (IV) analysis with a multisite randomized trial to estimate the effect of a mediating variable on an outcome in cases where it can be assumed that the observed mediator is the only mechanism linking treatment assignment to outcomes, an assumption known in the IV literature as the exclusion restriction.…

Variable Delay Element For Jitter Control In High Speed Data Links

DOEpatents

Livolsi, Robert R.

2002-06-11

A circuit and method for decreasing the amount of jitter present at the receiver input of high speed data links which uses a driver circuit for input from a high speed data link which comprises a logic circuit having a first section (1) which provides data latches, a second section (2) which provides a circuit generates a pre-destorted output and for compensating for level dependent jitter having an OR function element and a NOR function element each of which is coupled to two inputs and to a variable delay element as an input which provides a bi-modal delay for pulse width pre-distortion, a third section (3) which provides a muxing circuit, and a forth section (4) for clock distribution in the driver circuit. A fifth section is used for logic testing the driver circuit.

Experimental Test Rig for Optimal Control of Flexible Space Robotic Arms

DTIC Science & Technology

2016-12-01

was used to refine the test bed design and the experimental workflow. Three concepts incorporated various strategies to design a robust flexible link...used to refine the test bed design and the experimental workflow. Three concepts incorporated various strategies to design a robust flexible link... designed to perform the experimentation . The first and second concepts use traditional elastic springs in varying configurations while a third uses a

High skew link slab bridge system with deck sliding over backwall or backwall sliding over abutments : appendices.

DOT National Transportation Integrated Search

2011-09-01

AASHTO LRFD (2010) requires combined live and thermal load effects for the service : limit state design. The Design Procedure described in the appendix will follow the : rationale developed by Ulku et al. (2009). Link slab design moments are calculat...

A quality by design approach to optimization of emulsions for electrospinning using factorial and D-optimal designs.

PubMed

Badawi, Mariam A; El-Khordagui, Labiba K

2014-07-16

Emulsion electrospinning is a multifactorial process used to generate nanofibers loaded with hydrophilic drugs or macromolecules for diverse biomedical applications. Emulsion electrospinnability is greatly impacted by the emulsion pharmaceutical attributes. The aim of this study was to apply a quality by design (QbD) approach based on design of experiments as a risk-based proactive approach to achieve predictable critical quality attributes (CQAs) in w/o emulsions for electrospinning. Polycaprolactone (PCL)-thickened w/o emulsions containing doxycycline HCl were formulated using a Span 60/sodium lauryl sulfate (SLS) emulsifier blend. The identified emulsion CQAs (stability, viscosity and conductivity) were linked with electrospinnability using a 3(3) factorial design to optimize emulsion composition for phase stability and a D-optimal design to optimize stable emulsions for viscosity and conductivity after shifting the design space. The three independent variables, emulsifier blend composition, organic:aqueous phase ratio and polymer concentration, had a significant effect (p<0.05) on emulsion CQAs, the emulsifier blend composition exerting prominent main and interaction effects. Scanning electron microscopy (SEM) of emulsion-electrospun NFs and desirability functions allowed modeling of emulsion CQAs to predict electrospinnable formulations. A QbD approach successfully built quality in electrospinnable emulsions, allowing development of hydrophilic drug-loaded nanofibers with desired morphological characteristics. Copyright © 2014 Elsevier B.V. All rights reserved.

Defining process design space for monoclonal antibody cell culture.

PubMed

Abu-Absi, Susan Fugett; Yang, LiYing; Thompson, Patrick; Jiang, Canping; Kandula, Sunitha; Schilling, Bernhard; Shukla, Abhinav A

2010-08-15

The concept of design space has been taking root as a foundation of in-process control strategies for biopharmaceutical manufacturing processes. During mapping of the process design space, the multidimensional combination of operational variables is studied to quantify the impact on process performance in terms of productivity and product quality. An efficient methodology to map the design space for a monoclonal antibody cell culture process is described. A failure modes and effects analysis (FMEA) was used as the basis for the process characterization exercise. This was followed by an integrated study of the inoculum stage of the process which includes progressive shake flask and seed bioreactor steps. The operating conditions for the seed bioreactor were studied in an integrated fashion with the production bioreactor using a two stage design of experiments (DOE) methodology to enable optimization of operating conditions. A two level Resolution IV design was followed by a central composite design (CCD). These experiments enabled identification of the edge of failure and classification of the operational parameters as non-key, key or critical. In addition, the models generated from the data provide further insight into balancing productivity of the cell culture process with product quality considerations. Finally, process and product-related impurity clearance was evaluated by studies linking the upstream process with downstream purification. Production bioreactor parameters that directly influence antibody charge variants and glycosylation in CHO systems were identified.

PUBLIC HEALTH RISK ASSESSMENT LINKED TO CLIMATIC AND ECOLOGICAL CHANGE. (R824995)

EPA Science Inventory

Abstract

Disturbances of climatic and ecological systems can present risks to human health, which are becoming more evident from health studies linked to climate variability, landuse change and global climate change. Waterborne disease agents, such as Giardia cy...

Optimization of a GO2/GH2 Swirl Coaxial Injector Element

NASA Technical Reports Server (NTRS)

Tucker, P. Kevin; Shyy, Wei; Vaidyanathan, Rajkumar

1999-01-01

An injector optimization methodology, method i, is used to investigate optimal design points for a gaseous oxygen/gaseous hydrogen (GO2/GH2) swirl coaxial injector element. The element is optimized in terms of design variables such as fuel pressure drop, DELTA P(sub f), oxidizer pressure drop, DELTA P(sub 0) combustor length, L(sub comb), and full cone swirl angle, theta, for a given mixture ratio and chamber pressure. Dependent variables such as energy release efficiency, ERE, wall heat flux, Q(sub w) injector heat flux, Q(sub inj), relative combustor weight, W(sub rel), and relative injector cost, C(sub rel), are calculated and then correlated with the design variables. An empirical design methodology is used to generate these responses for 180 combinations of input variables. Method i is then used to generate response surfaces for each dependent variable. Desirability functions based on dependent variable constraints are created and used to facilitate development of composite response surfaces representing some, or all, of the five dependent variables in terms of the input variables. Two examples illustrating the utility and flexibility of method i are discussed in detail. First, joint response surfaces are constructed by sequentially adding dependent variables. Optimum designs are identified after addition of each variable and the effect each variable has on the design is shown. This stepwise demonstration also highlights the importance of including variables such as weight and cost early in the design process. Secondly, using the composite response surface that includes all five dependent variables, unequal weights are assigned to emphasize certain variables relative to others. Here, method i is used to enable objective trade studies on design issues such as component life and thrust to weight ratio.

Dimensionnement des actionneurs électriques alimentés à fréquence variable sous faible tension

NASA Astrophysics Data System (ADS)

Biedinger, J.-M.; Vilain, J.-P.

1999-09-01

In Part I we present a multidisciplinary analysis model for the prediction of functional connections between the design variables and the electromagnetical, electrical and thermal performances of a brushless permanent magnet motor. In this paper we have elaborated a design methodology for electrical motors supplied from a variable-frequency low-voltage source. The objective is to take into account the influence of the inverter's dynamics from the beginning of the design, for the same reasons as we do for electromechanical and thermal constraints. The procedure is based on a Sequential Quadratic Programming optimization method. Two techniques are used to take into account the influence of the inverter: the first one develops the performance analysis with the multidisciplinary model; the second one considers the inverter's current reference as a supplementary optimization variable for the control of the design. Optimization difficulties linked to the chopping of the converter are discuted in connection with a sensitivity analysis of the torque, with respect to the inverter's current reference; a method is proposed to enhance the performances of the algorithm. The method has been applied to the design of a permanent magnet brushless DC motor used in the propulsion system of an electrical scooter; evolution of the design with the complexity level of analysis model is evidenced. Dans une première partie nous avons développé un modèle d'analyse pluridisciplinaire qui établissait les dépendances fonctionnelles entre les variables de conception et les performances magnéto-électro-thermiques d'un moteur brushless à aimants permanents. Dans cet article nous décrivons une procédure de dimensionnement adaptée à la conception de la machine alimentée à fréquence variable sous faible tension. L'objectif est d'intégrer la dynamique du convertisseur électronique dès la phase initiale du dimensionnement, au même titre que les spécifications électromécaniques et thermiques. La procédure est gérée par une méthode d'optimisation déterministe de type Programmation Quadratique Séquentielle. Elle intègre l'influence du convertisseur au moyen de deux spécificités : la première consiste à évaluer les fonctions du problème d'optimisation sur la base du module d'analyse pluridisciplinaire ; la deuxième permet de contrôler l'évolution du dimensionnement au travers de variables d'optimisation dont la liste inclut les consignes de la commande en courant du convertisseur. Les difficultés d'optimisation liées au mode de fonctionnement discret du convertisseur sont discutées au regard du calcul de la sensibilité du couple électromagnétique envers la consigne de courant du convertisseur ; une méthode est proposée pour assurer la robustesse de la procédure en présence du convertisseur. L'application porte sur le dimensionnement d'un moteur à aimants permanents de type “brushless trapézoïdal" destiné à la traction d'un scooter électrique ; l'évolution de la structure optimale avec le degré de complexité du module d'analyse est mise en évidence.

Hybrid robust model based on an improved functional link neural network integrating with partial least square (IFLNN-PLS) and its application to predicting key process variables.

PubMed

He, Yan-Lin; Xu, Yuan; Geng, Zhi-Qiang; Zhu, Qun-Xiong

2016-03-01

In this paper, a hybrid robust model based on an improved functional link neural network integrating with partial least square (IFLNN-PLS) is proposed. Firstly, an improved functional link neural network with small norm of expanded weights and high input-output correlation (SNEWHIOC-FLNN) was proposed for enhancing the generalization performance of FLNN. Unlike the traditional FLNN, the expanded variables of the original inputs are not directly used as the inputs in the proposed SNEWHIOC-FLNN model. The original inputs are attached to some small norm of expanded weights. As a result, the correlation coefficient between some of the expanded variables and the outputs is enhanced. The larger the correlation coefficient is, the more relevant the expanded variables tend to be. In the end, the expanded variables with larger correlation coefficient are selected as the inputs to improve the performance of the traditional FLNN. In order to test the proposed SNEWHIOC-FLNN model, three UCI (University of California, Irvine) regression datasets named Housing, Concrete Compressive Strength (CCS), and Yacht Hydro Dynamics (YHD) are selected. Then a hybrid model based on the improved FLNN integrating with partial least square (IFLNN-PLS) was built. In IFLNN-PLS model, the connection weights are calculated using the partial least square method but not the error back propagation algorithm. Lastly, IFLNN-PLS was developed as an intelligent measurement model for accurately predicting the key variables in the Purified Terephthalic Acid (PTA) process and the High Density Polyethylene (HDPE) process. Simulation results illustrated that the IFLNN-PLS could significant improve the prediction performance. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Robust parameter design for automatically controlled systems and nanostructure synthesis

NASA Astrophysics Data System (ADS)

Dasgupta, Tirthankar

2007-12-01

This research focuses on developing comprehensive frameworks for developing robust parameter design methodology for dynamic systems with automatic control and for synthesis of nanostructures. In many automatically controlled dynamic processes, the optimal feedback control law depends on the parameter design solution and vice versa and therefore an integrated approach is necessary. A parameter design methodology in the presence of feedback control is developed for processes of long duration under the assumption that experimental noise factors are uncorrelated over time. Systems that follow a pure-gain dynamic model are considered and the best proportional-integral and minimum mean squared error control strategies are developed by using robust parameter design. The proposed method is illustrated using a simulated example and a case study in a urea packing plant. This idea is also extended to cases with on-line noise factors. The possibility of integrating feedforward control with a minimum mean squared error feedback control scheme is explored. To meet the needs of large scale synthesis of nanostructures, it is critical to systematically find experimental conditions under which the desired nanostructures are synthesized reproducibly, at large quantity and with controlled morphology. The first part of the research in this area focuses on modeling and optimization of existing experimental data. Through a rigorous statistical analysis of experimental data, models linking the probabilities of obtaining specific morphologies to the process variables are developed. A new iterative algorithm for fitting a Multinomial GLM is proposed and used. The optimum process conditions, which maximize the above probabilities and make the synthesis process less sensitive to variations of process variables around set values, are derived from the fitted models using Monte-Carlo simulations. The second part of the research deals with development of an experimental design methodology, tailor-made to address the unique phenomena associated with nanostructure synthesis. A sequential space filling design called Sequential Minimum Energy Design (SMED) for exploring best process conditions for synthesis of nanowires. The SMED is a novel approach to generate sequential designs that are model independent, can quickly "carve out" regions with no observable nanostructure morphology, and allow for the exploration of complex response surfaces.

On the Asymptotic Relative Efficiency of Planned Missingness Designs.

PubMed

Rhemtulla, Mijke; Savalei, Victoria; Little, Todd D

2016-03-01

In planned missingness (PM) designs, certain data are set a priori to be missing. PM designs can increase validity and reduce cost; however, little is known about the loss of efficiency that accompanies these designs. The present paper compares PM designs to reduced sample (RN) designs that have the same total number of data points concentrated in fewer participants. In 4 studies, we consider models for both observed and latent variables, designs that do or do not include an "X set" of variables with complete data, and a full range of between- and within-set correlation values. All results are obtained using asymptotic relative efficiency formulas, and thus no data are generated; this novel approach allows us to examine whether PM designs have theoretical advantages over RN designs removing the impact of sampling error. Our primary findings are that (a) in manifest variable regression models, estimates of regression coefficients have much lower relative efficiency in PM designs as compared to RN designs, (b) relative efficiency of factor correlation or latent regression coefficient estimates is maximized when the indicators of each latent variable come from different sets, and (c) the addition of an X set improves efficiency in manifest variable regression models only for the parameters that directly involve the X-set variables, but it substantially improves efficiency of most parameters in latent variable models. We conclude that PM designs can be beneficial when the model of interest is a latent variable model; recommendations are made for how to optimize such a design.

Circuit-level simulation of transistor lasers and its application to modelling of microwave photonic links

NASA Astrophysics Data System (ADS)

Iezekiel, Stavros; Christou, Andreas

2015-03-01

Equivalent circuit models of a transistor laser are used to investigate the suitability of this relatively new device for analog microwave photonic links. The three-terminal nature of the device enables transistor-based circuit design techniques to be applied to optoelectronic transmitter design. To this end, we investigate the application of balanced microwave amplifier topologies in order to enable low-noise links to be realized with reduced intermodulation distortion and improved RF impedance matching compared to conventional microwave photonic links.

In search of new lead compounds for trypanosomiasis drug design: A protein structure-based linked-fragment approach

NASA Astrophysics Data System (ADS)

Verlinde, Christophe L. M. J.; Rudenko, Gabrielle; Hol, Wim G. J.

1992-04-01

A modular method for pursuing structure-based inhibitor design in the framework of a design cycle is presented. The approach entails four stages: (1) a design pathway is defined in the three-dimensional structure of a target protein; (2) this pathway is divided into subregions; (3) complementary building blocks, also called fragments, are designed in each subregion; complementarity is defined in terms of shape, hydrophobicity, hydrogen bond properties and electrostatics; and (4) fragments from different subregions are linked into potential lead compounds. Stages (3) and (4) are qualitatively guided by force-field calculations. In addition, the designed fragments serve as entries for retrieving existing compounds from chemical databases. This linked-fragment approach has been applied in the design of potentially selective inhibitors of triosephosphate isomerase from Trypanosoma brucei, the causative agent of sleeping sickness.

A quality by design study applied to an industrial pharmaceutical fluid bed granulation.

PubMed

Lourenço, Vera; Lochmann, Dirk; Reich, Gabriele; Menezes, José C; Herdling, Thorsten; Schewitz, Jens

2012-06-01

The pharmaceutical industry is encouraged within Quality by Design (QbD) to apply science-based manufacturing principles to assure quality not only of new but also of existing processes. This paper presents how QbD principles can be applied to an existing industrial pharmaceutical fluid bed granulation (FBG) process. A three-step approach is presented as follows: (1) implementation of Process Analytical Technology (PAT) monitoring tools at the industrial scale process, combined with multivariate data analysis (MVDA) of process and PAT data to increase the process knowledge; (2) execution of scaled-down designed experiments at a pilot scale, with adequate PAT monitoring tools, to investigate the process response to intended changes in Critical Process Parameters (CPPs); and finally (3) the definition of a process Design Space (DS) linking CPPs to Critical to Quality Attributes (CQAs), within which product quality is ensured by design, and after scale-up enabling its use at the industrial process scale. The proposed approach was developed for an existing industrial process. Through enhanced process knowledge established a significant reduction in product CQAs, variability already within quality specifications ranges was achieved by a better choice of CPPs values. The results of such step-wise development and implementation are described. Copyright © 2012 Elsevier B.V. All rights reserved.

A test of safety, violence prevention, and civility climate domain-specific relationships with relevant workplace hazards.

PubMed

Gazica, Michele W; Spector, Paul E

2016-01-01

Safety climate, violence prevention climate, and civility climate were independently developed and linked to domain-specific workplace hazards, although all three were designed to promote the physical and psychological safety of workers. To test domain specificity between conceptually related workplace climates and relevant workplace hazards. Data were collected from 368 persons employed in various industries and descriptive statistics were calculated for all study variables. Correlational and relative weights analyses were used to test for domain specificity. The three climate domains were similarly predictive of most workplace hazards, regardless of domain specificity. This study suggests that the three climate domains share a common higher order construct that may predict relevant workplace hazards better than any of the scales alone.

Power and energy ratios in mechanical CVT drive control

NASA Astrophysics Data System (ADS)

Balakin, P. D.; Stripling, L. O.

2017-06-01

Being based on the principle of providing the systems with adaptation property to the real parameters and operational condition, the mechanical system capable to control automatically the components of convertible power is offered and this allows providing stationary operation of the vehicle engine in the terms of variable external loading. This is achieved by drive control integrated in the power transmission, which implements an additional degree of freedom and operates on the basis of the laws of motion, with the energy of the main power flow by changing automatically the kinematic characteristics of the power transmission, this system being named CVT. The power and energy ratios found allow performing the necessary design calculations of the sections and the links of the mechanical CVT scheme.

Scientific and Regulatory Perspectives in Herbal and Dietary Supplement Associated Hepatotoxicity in the United States

PubMed Central

Avigan, Mark I.; Mozersky, Robert P.; Seeff, Leonard B.

2016-01-01

In the United States (US), the risk of hepatotoxicity linked to the widespread use of certain herbal products has gained increased attention among regulatory scientists. Based on current US law, all dietary supplements sold domestically, including botanical supplements, are regulated by the Food and Drug Administration (FDA) as a special category of foods. Under this designation, regulatory scientists do not routinely evaluate the efficacy of these products prior to their marketing, despite the content variability and phytochemical complexity that often characterizes them. Nonetheless, there has been notable progress in the development of advanced scientific methods to qualitatively and quantitatively measure ingredients and screen for contaminants and adulterants in botanical products when hepatotoxicity is recognized. PMID:26950122

Ceramic component reliability with the restructured NASA/CARES computer program

NASA Technical Reports Server (NTRS)

Powers, Lynn M.; Starlinger, Alois; Gyekenyesi, John P.

1992-01-01

The Ceramics Analysis and Reliability Evaluation of Structures (CARES) integrated design program on statistical fast fracture reliability and monolithic ceramic components is enhanced to include the use of a neutral data base, two-dimensional modeling, and variable problem size. The data base allows for the efficient transfer of element stresses, temperatures, and volumes/areas from the finite element output to the reliability analysis program. Elements are divided to insure a direct correspondence between the subelements and the Gaussian integration points. Two-dimensional modeling is accomplished by assessing the volume flaw reliability with shell elements. To demonstrate the improvements in the algorithm, example problems are selected from a round-robin conducted by WELFEP (WEakest Link failure probability prediction by Finite Element Postprocessors).

Hypothesis driven assessment of an NMR curriculum

NASA Astrophysics Data System (ADS)

Cossey, Kimberly

The goal of this project was to develop a battery of assessments to evaluate an undergraduate NMR curriculum at Penn State University. As a chemical education project, we sought to approach the problem of curriculum assessment from a scientific perspective, while remaining grounded in the education research literature and practices. We chose the phrase hypothesis driven assessment to convey this process of relating the scientific method to the study of educational methods, modules, and curricula. We began from a hypothesis, that deeper understanding of one particular analytical technique (NMR) will increase undergraduate students' abilities to solve chemical problems. We designed an experiment to investigate this hypothesis, and data collected were analyzed and interpreted in light of the hypothesis and several related research questions. The expansion of the NMR curriculum at Penn State was funded through the NSF's Course, Curriculum, and Laboratory Improvement (CCLI) program, and assessment was required. The goal of this project, as stated in the grant proposal, was to provide NMR content in greater depth by integrating NMR modules throughout the curriculum in physical chemistry, instrumental, and organic chemistry laboratory courses. Hands-on contact with the NMR spectrometer and NMR data and repeated exposure of the analytical technique within different contexts (courses) were unique factors of this curriculum. Therefore, we maintained a focus on these aspects throughout the evaluation process. The most challenging and time-consuming aspect of any assessment is the development of testing instruments and methods to provide useful data. After key variables were defined, testing instruments were designed to measure these variables based on educational literature (Chapter 2). The primary variables measured in this assessment were: depth of understanding of NMR, basic NMR knowledge, problem solving skills (HETCOR problem), confidence for skills used in class (within the hands-on NMR modules), confidence for NMR tasks (not practiced), and confidence for general science tasks. Detailed discussion of the instruments, testing methods and experimental design used in this assessment are provided (Chapter 3). All data were analyzed quantitatively using methods adapted from the educational literature (Chapter 4). Data were analyzed and the descriptive statistics, independent t-tests between the experimental and control groups, and correlation statistics were calculated for each variable. In addition, for those variables included on the pretest, dependent t-tests between pretest and posttest scores were also calculated. The results of study 1 and study 2 were used to draw conclusions based on the hypothesis and research questions proposed in this work (Chapter 4). Data collected in this assessment were used to answer the following research questions: (1) Primary research question: Is depth of understanding of NMR linked to problem solving skills? (2) Are the NMR modules working as intended? Do they promote depth of understanding of NMR? (a) Will students who complete NMR modules have a greater depth of understanding of NMR than students who do not complete the modules? (b) Is depth of understanding increasing over the course of the experiment? (3) Is confidence an intermediary between depth of understanding and problem solving skills? Is it linked to both variables? (4) What levels of confidence are affected by the NMR modules? (a) Will confidence for the NMR class skills used in the modules themselves be greater for those who have completed the modules? (b) Will confidence for NMR tasks not practiced in the course be affected? (c) Will confidence for general science tasks be affected? (d) Are different levels of confidence (class skills, NMR tasks, general science tasks) linked to each other? Results from this NMR curriculum assessment could also have implications outside of the courses studied, and so there is potential to impact the chemical education community (section 5.2.1). In addition to providing reliable testing instruments/measures that could be used outside the university, the results of this research contribute to the study of problem solving in chemistry, learner characteristics within the context of chemical education studies, and NMR specific educational evaluations. Valuable information was gathered through the current method of evaluation for the NMR curriculum. However, improvements could be made to the existing assessment, and an alternate assessment that could supplement the information found in this study has been proposed (Chapter 5).

Linked shoulder replacement: current design problems and a new design proposal.

PubMed

Mohammed, Ali Abdullah; Frostick, Simon Peter

2016-04-01

Totally constrained shoulder replacement with linked components is one of the surgical options in post-tumor resection shoulder reconstruction or in complex shoulder revision operations. In this paper, we intend to shed light on such an implant design, which provides a linked constrained connection between the humeral head and the glenoid, and to show some immediate postoperative complications, implant progression to decrease the chances of implant mechanical postinsertion failure, and a new design proposal. In our center, we use the linked prosthesis in complex revision situations; however, there have been some complications, which could be attributed mainly to the engineering and the implant design, and hence potentially avoidable by making a different design to cover for those mechanical issues. Two such complications are described in this paper. Early revisions after linked shoulder replacement implantation were needed in two occasions due to implant disconnection: one of them was due to dislodgement from the native glenoid, and the second one was due to the disengagement of the ringlet which secures the linkage mechanism between the humeral head and the implanted glenoid shell. There is a need for a more stable design construct to avoid the reported complications that needed early revision surgeries. The new design proposed is an attempt to help providing a better and more stable implant to decrease the chances of revision in those complex situations where the patient already had many major operations, and working to increase the durability of the implant is crucial.

Variation, Repetition, and Choice

ERIC Educational Resources Information Center

Abreu-Rodrigues, Josele; Lattal, Kennon A.; dos Santos, Cristiano V.; Matos, Ricardo A.

2005-01-01

Experiment 1 investigated the controlling properties of variability contingencies on choice between repeated and variable responding. Pigeons were exposed to concurrent-chains schedules with two alternatives. In the REPEAT alternative, reinforcers in the terminal link depended on a single sequence of four responses. In the VARY alternative, a…

Variability of Travel Times on New Jersey Highways

DOT National Transportation Integrated Search

2011-06-01

This report presents the results of a link and path travel time study conducted on selected New Jersey (NJ) highways to produce estimates of the corresponding variability of travel time (VTT) by departure time of the day and days of the week. The tra...

Combining Variables, Controlling Variables, and Proportions: Is There a Psychological Link?

ERIC Educational Resources Information Center

Lawson, Anton E.

1979-01-01

Investigated the degree of relationship among the performance of 28 seventh grade students on the following three formal operations tasks: chemical combinations, bending rods, and balance beam. Results show that task performance ranged widely from early concrete operational to fully operational. (HM)

Structural considerations for functional anti-EGFR × anti-CD3 bispecific diabodies in light of domain order and binding affinity.

PubMed

Asano, Ryutaro; Nagai, Keisuke; Makabe, Koki; Takahashi, Kento; Kumagai, Takashi; Kawaguchi, Hiroko; Ogata, Hiromi; Arai, Kyoko; Umetsu, Mitsuo; Kumagai, Izumi

2018-03-02

We previously reported a functional humanized bispecific diabody (bsDb) that targeted EGFR and CD3 (hEx3-Db) and enhancement of its cytotoxicity by rearranging the domain order in the V domain. Here, we further dissected the effect of domain order in bsDbs on their cross-linking ability and binding kinetics to elucidate general rules regarding the design of functional bsDbs. Using Ex3-Db as a model system, we first classified the four possible domain orders as anti-parallel (where both chimeric single-chain components are variable heavy domain (VH)-variable light domain (VL) or VL-VH order) and parallel types (both chimeric single-chain components are mixed with VH-VL and VL-VH order). Although anti-parallel Ex3-Dbs could cross-link the soluble target antigens, their cross-linking ability between soluble targets had no correlation with their growth inhibitory effects. In contrast, the binding affinity of one of the two constructs with a parallel-arrangement V domain was particularly low, and structural modeling supported this phenomenon. Similar results were observed with E2x3-Dbs, in which the V region of the anti-EGFR antibody clone in hEx3 was replaced with that of another anti-EGFR clone. Only anti-parallel types showed affinity-dependent cancer inhibitory effects in each molecule, and E2x3-LH (both components in VL-VH order) showed the most intense anti-tumor activity in vitro and in vivo . Our results showed that, in addition to rearranging the domain order of bsDbs, increasing their binding affinity may be an ideal strategy for enhancing the cytotoxicity of anti-parallel constructs and that E2x3-LH is particularly attractive as a candidate next-generation anti-cancer drug.

A Bayesian model for estimating population means using a link-tracing sampling design.

PubMed

St Clair, Katherine; O'Connell, Daniel

2012-03-01

Link-tracing sampling designs can be used to study human populations that contain "hidden" groups who tend to be linked together by a common social trait. These links can be used to increase the sampling intensity of a hidden domain by tracing links from individuals selected in an initial wave of sampling to additional domain members. Chow and Thompson (2003, Survey Methodology 29, 197-205) derived a Bayesian model to estimate the size or proportion of individuals in the hidden population for certain link-tracing designs. We propose an addition to their model that will allow for the modeling of a quantitative response. We assess properties of our model using a constructed population and a real population of at-risk individuals, both of which contain two domains of hidden and nonhidden individuals. Our results show that our model can produce good point and interval estimates of the population mean and domain means when our population assumptions are satisfied. © 2011, The International Biometric Society.

Providing nearest neighbor point-to-point communications among compute nodes of an operational group in a global combining network of a parallel computer

DOEpatents

Archer, Charles J.; Faraj, Ahmad A.; Inglett, Todd A.; Ratterman, Joseph D.

2012-10-23

Methods, apparatus, and products are disclosed for providing nearest neighbor point-to-point communications among compute nodes of an operational group in a global combining network of a parallel computer, each compute node connected to each adjacent compute node in the global combining network through a link, that include: identifying each link in the global combining network for each compute node of the operational group; designating one of a plurality of point-to-point class routing identifiers for each link such that no compute node in the operational group is connected to two adjacent compute nodes in the operational group with links designated for the same class routing identifiers; and configuring each compute node of the operational group for point-to-point communications with each adjacent compute node in the global combining network through the link between that compute node and that adjacent compute node using that link's designated class routing identifier.

The effect of implant design of linked total elbow arthroplasty on stability and stress: a finite element analysis.

PubMed

Willing, Ryan; King, Graham J W; Johnson, James A

2014-01-01

Several linked total elbow arthroplasty designs exist, which function similar to a loose hinge joint. Constraint behaviour is an important design consideration, as it affects joint stability, or how much secondary [e.g. varus-valgus (VV)] motion is permitted. Implant durability is also a concern, as bearing failures have been reported. This finite element analysis investigates the constraint characteristics and ultra high molecular weight polyethylene bearing stresses of three linked elbow design concepts [cylindrical (CY), hourglass (HG) and concave cylinder (CC)]. The bearing of the CY design was subjected to elevated Von Mises stresses (2.1-5.4 times higher than the HG and CC designs) due to edge loading. The HG design maintained low stresses, but was unable to provide consistent VV stability. The CC design also maintained low stresses while providing consistent VV stability. These results suggest that CC designs may provide better stability characteristics and durability in vivo, compared to the other two designs.

Hazardous alcohol use and intimate partner violence in the military: understanding protective factors.

PubMed

Foran, Heather M; Heyman, Richard E; Smith Slep, Amy M; Snarr, Jeffery D

2012-09-01

Hazardous alcohol use is a well-established risk factor for men's intimate partner violence (IPV), with dozens of studies demonstrating the association. The current study extends understanding of the hazardous alcohol use-IPV link by examining what factors moderate this association in a more systematic and broader way that has been done in past studies. Individual, family, workplace, community, and developmental factors were tested as moderators of the hazardous alcohol use and IPV link in a large, representative sample of active duty service members (the 2006 Community Assessment), and the results were tested for replicability in a hold-out sample. Two family variables (relationship satisfaction and parent-child satisfaction), 1 community variable (community safety), and 3 developmental variables (years in the military, marital length, and family income/pay grade) cross-validated as significant moderators of the association between men's hazardous alcohol use and IPV. Across the significant moderators, the association between hazardous alcohol use and men's IPV was weakened by maturation/development, improved community safety, and better relationship functioning. No individual or workplace variables were significant moderators for men, and there were no significant moderators found for women. The results support the importance of a developmental and relational perspective to understanding the hazardous alcohol use-IPV link, rather than solely an individual coping perspective. PsycINFO Database Record (c) 2012 APA, all rights reserved.

Continuous-variable quantum cryptography with an untrusted relay: Detailed security analysis of the symmetric configuration

NASA Astrophysics Data System (ADS)

Ottaviani, Carlo; Spedalieri, Gaetana; Braunstein, Samuel L.; Pirandola, Stefano

2015-02-01

We consider the continuous-variable protocol of Pirandola et al. [arXiv:1312.4104] where the secret key is established by the measurement of an untrusted relay. In this network protocol, two authorized parties are connected to an untrusted relay by insecure quantum links. Secret correlations are generated by a continuous-variable Bell detection performed on incoming coherent states. In the present work we provide a detailed study of the symmetric configuration, where the relay is midway between the parties. We analyze symmetric eavesdropping strategies against the quantum links explicitly showing that, at fixed transmissivity and thermal noise, two-mode coherent attacks are optimal, manifestly outperforming one-mode collective attacks based on independent entangling cloners. Such an advantage is shown both in terms of security threshold and secret-key rate.

Nanophotonic Devices in Silicon for Nonlinear Optics

DTIC Science & Technology

2010-10-15

record performance  Demonstration of world‟s lowest loss slot waveguides, made in a DOD-trusted foundry (BAE Systems)  Design study showing...highly-cited design study.  Design study on analog links using the above modulators.  Demonstration of the first silicon waveguides for the mid...Hochberg. Design of transmission line driven slot waveguide Mach-Zehnder interferometers and application to analog optical links. Optics Express 2010

A top-down design methodology and its implementation for VCSEL-based optical links design

NASA Astrophysics Data System (ADS)

Li, Jiguang; Cao, Mingcui; Cai, Zilong

2005-01-01

In order to find the optimal design for a given specification of an optical communication link, an integrated simulation of electronic, optoelectronic, and optical components of a complete system is required. It is very important to be able to simulate at both system level and detailed model level. This kind of model is feasible due to the high potential of Verilog-AMS language. In this paper, we propose an effective top-down design methodology and employ it in the development of a complete VCSEL-based optical links simulation. The principle of top-down methodology is that the development would proceed from the system to device level. To design a hierarchical model for VCSEL based optical links, the design framework is organized in three levels of hierarchy. The models are developed, and implemented in Verilog-AMS. Therefore, the model parameters are fitted to measured data. A sample transient simulation demonstrates the functioning of our implementation. Suggestions for future directions in top-down methodology used for optoelectronic systems technology are also presented.

Structural Variability within Frontoparietal Networks and Individual Differences in Attentional Functions: An Approach Using the Theory of Visual Attention.

PubMed

Chechlacz, Magdalena; Gillebert, Celine R; Vangkilde, Signe A; Petersen, Anders; Humphreys, Glyn W

2015-07-29

Visuospatial attention allows us to select and act upon a subset of behaviorally relevant visual stimuli while ignoring distraction. Bundesen's theory of visual attention (TVA) (Bundesen, 1990) offers a quantitative analysis of the different facets of attention within a unitary model and provides a powerful analytic framework for understanding individual differences in attentional functions. Visuospatial attention is contingent upon large networks, distributed across both hemispheres, consisting of several cortical areas interconnected by long-association frontoparietal pathways, including three branches of the superior longitudinal fasciculus (SLF I-III) and the inferior fronto-occipital fasciculus (IFOF). Here we examine whether structural variability within human frontoparietal networks mediates differences in attention abilities as assessed by the TVA. Structural measures were based on spherical deconvolution and tractography-derived indices of tract volume and hindrance-modulated orientational anisotropy (HMOA). Individual differences in visual short-term memory (VSTM) were linked to variability in the microstructure (HMOA) of SLF II, SLF III, and IFOF within the right hemisphere. Moreover, VSTM and speed of information processing were linked to hemispheric lateralization within the IFOF. Differences in spatial bias were mediated by both variability in microstructure and volume of the right SLF II. Our data indicate that the microstructural and macrostrucutral organization of white matter pathways differentially contributes to both the anatomical lateralization of frontoparietal attentional networks and to individual differences in attentional functions. We conclude that individual differences in VSTM capacity, processing speed, and spatial bias, as assessed by TVA, link to variability in structural organization within frontoparietal pathways. Copyright © 2015 Chechlacz et al.

Decadal-timescale changes of the Atlantic overturning circulation and climate in a coupled climate model with a hybrid-coordinate ocean component

NASA Astrophysics Data System (ADS)

Persechino, A.; Marsh, R.; Sinha, B.; Megann, A. P.; Blaker, A. T.; New, A. L.

2012-08-01

A wide range of statistical tools is used to investigate the decadal variability of the Atlantic Meridional Overturning Circulation (AMOC) and associated key variables in a climate model (CHIME, Coupled Hadley-Isopycnic Model Experiment), which features a novel ocean component. CHIME is as similar as possible to the 3rd Hadley Centre Coupled Model (HadCM3) with the important exception that its ocean component is based on a hybrid vertical coordinate. Power spectral analysis reveals enhanced AMOC variability for periods in the range 15-30 years. Strong AMOC conditions are associated with: (1) a Sea Surface Temperature (SST) anomaly pattern reminiscent of the Atlantic Multi-decadal Oscillation (AMO) response, but associated with variations in a northern tropical-subtropical gradient; (2) a Surface Air Temperature anomaly pattern closely linked to SST; (3) a positive North Atlantic Oscillation (NAO)-like pattern; (4) a northward shift of the Intertropical Convergence Zone. The primary mode of AMOC variability is associated with decadal changes in the Labrador Sea and the Greenland Iceland Norwegian (GIN) Seas, in both cases linked to the tropical activity about 15 years earlier. These decadal changes are controlled by the low-frequency NAO that may be associated with a rapid atmospheric teleconnection from the tropics to the extratropics. Poleward advection of salinity anomalies in the mixed layer also leads to AMOC changes that are linked to processes in the Labrador Sea. A secondary mode of AMOC variability is associated with interannual changes in the Labrador and GIN Seas, through the impact of the NAO on local surface density.

Optimization of a GO2/GH2 Impinging Injector Element

NASA Technical Reports Server (NTRS)

Tucker, P. Kevin; Shyy, Wei; Vaidyanathan, Rajkumar

2001-01-01

An injector optimization methodology, method i, is used to investigate optimal design points for a gaseous oxygen/gaseous hydrogen (GO2/GH2) impinging injector element. The unlike impinging element, a fuel-oxidizer- fuel (F-O-F) triplet, is optimized in terms of design variables such as fuel pressure drop, (Delta)P(sub f), oxidizer pressure drop, (Delta)P(sub o), combustor length, L(sub comb), and impingement half-angle, alpha, for a given mixture ratio and chamber pressure. Dependent variables such as energy release efficiency, ERE, wall heat flux, Q(sub w), injector heat flux, Q(sub inj), relative combustor weight, W(sub rel), and relative injector cost, C(sub rel), are calculated and then correlated with the design variables. An empirical design methodology is used to generate these responses for 163 combinations of input variables. Method i is then used to generate response surfaces for each dependent variable. Desirability functions based on dependent variable constraints are created and used to facilitate development of composite response surfaces representing some, or all, of the five dependent variables in terms of the input variables. Three examples illustrating the utility and flexibility of method i are discussed in detail. First, joint response surfaces are constructed by sequentially adding dependent variables. Optimum designs are identified after addition of each variable and the effect each variable has on the design is shown. This stepwise demonstration also highlights the importance of including variables such as weight and cost early in the design process. Secondly, using the composite response surface which includes all five dependent variables, unequal weights are assigned to emphasize certain variables relative to others. Here, method i is used to enable objective trade studies on design issues such as component life and thrust to weight ratio. Finally, specific variable weights are further increased to illustrate the high marginal cost of realizing the last increment of injector performance and thruster weight.

LARGE-SCALE PATTERNS OF STREAMFLOW DISTURBANCE AND FISH COMMUNITIES IN UPPER MISSOURI RIVER BASIN, USA

EPA Science Inventory

Patterns of streamflow variability are likely to be a major organizing feature of the habitat template for stream fishes. Functional organization of stream communities has been linked to streamflow, especially to patterns of flow variability that describe the physical disturbanc...

LARGE-SCALE PATTERNS OF STREAMFLOW DISTURBANCE AND FISH ASSEMBLAGES IN UPPER MISSOURI RIVER BASIN, USA

EPA Science Inventory

Patterns of streamflow variability are likely to be a major organizing feature of the habitat template for stream fishes. Ecological organization of stream communities has been linked to streamflow, especially to patterns of flow variability that describe the physical disturbanc...

Smoking Is So Ew!: College Smokers' Reactions to Health- Versus Social-Focused Antismoking Threat Messages.

PubMed

Wong, Norman C H; Nisbett, Gwendelyn S; Harvell, Lindsey A

2017-04-01

This study utilizes Terror Management Theory (TMT) to examine differences between eliciting social death and physical death anxiety related to smoking, smoking attitudes, and quitting intent among college students. Moreover, an important TMT variable-self-esteem-was used as a moderator. A 2 × 3 between-subjects factorial design crossed smoking-based self-esteem (low, high) with mortality salience manipulation (health-focused, social-focused, control). Results suggest while both making health-focused salient and making social-focused mortality salient were effective at getting smokers to quit, there was less effect for health-focused mortality salience on those whose self-esteem is strongly tied to smoking. Effect of social-focused mortality salience was more pronounced among participants who highly linked self-esteem with smoking. For smokers with low smoking-based self-esteem, both health-focused and social-focused mortality salience were effective at motivating attitude change toward smoking and quitting intentions. Implications for smoking cessation ad design and TMT are discussed.

Modulation of the phenolic composition and colour of red wines subjected to accelerated ageing by controlling process variables.

PubMed

González-Sáiz, J M; Esteban-Díez, I; Rodríguez-Tecedor, S; Pérez-Del-Notario, N; Arenzana-Rámila, I; Pizarro, C

2014-12-15

The aim of the present work was to evaluate the effect of the main factors conditioning accelerated ageing processes (oxygen dose, chip dose, wood origin, toasting degree and maceration time) on the phenolic and chromatic profiles of red wines by using a multivariate strategy based on experimental design methodology. The results obtained revealed that the concentrations of monomeric anthocyanins and flavan-3-ols could be modified through the application of particular experimental conditions. This fact was particularly remarkable since changes in phenolic profile were closely linked to changes observed in chromatic parameters. The main strength of this study lies in the possibility of using its conclusions as a basis to make wines with specific colour properties based on quality criteria. To our knowledge, the influence of such a large number of alternative ageing parameters on wine phenolic composition and chromatic attributes has not been studied previously using a comprehensive experimental design methodology. Copyright © 2014 Elsevier Ltd. All rights reserved.

Computer-Aided Design of Low-Noise Microwave Circuits

NASA Astrophysics Data System (ADS)

Wedge, Scott William

1991-02-01

Devoid of most natural and manmade noise, microwave frequencies have detection sensitivities limited by internally generated receiver noise. Low-noise amplifiers are therefore critical components in radio astronomical antennas, communications links, radar systems, and even home satellite dishes. A general technique to accurately predict the noise performance of microwave circuits has been lacking. Current noise analysis methods have been limited to specific circuit topologies or neglect correlation, a strong effect in microwave devices. Presented here are generalized methods, developed for computer-aided design implementation, for the analysis of linear noisy microwave circuits comprised of arbitrarily interconnected components. Included are descriptions of efficient algorithms for the simultaneous analysis of noisy and deterministic circuit parameters based on a wave variable approach. The methods are therefore particularly suited to microwave and millimeter-wave circuits. Noise contributions from lossy passive components and active components with electronic noise are considered. Also presented is a new technique for the measurement of device noise characteristics that offers several advantages over current measurement methods.

On the identifiability of inertia parameters of planar Multi-Body Space Systems

NASA Astrophysics Data System (ADS)

Nabavi-Chashmi, Seyed Yaser; Malaek, Seyed Mohammad-Bagher

2018-04-01

This work describes a new formulation to study the identifiability characteristics of Serially Linked Multi-body Space Systems (SLMBSS). The process exploits the so called "Lagrange Formulation" to develop a linear form of Equations of Motion w.r.t the system Inertia Parameters (IPs). Having developed a specific form of regressor matrix, we aim to expedite the identification process. The new approach allows analytical as well as numerical identification and identifiability analysis for different SLMBSSs' configurations. Moreover, the explicit forms of SLMBSSs identifiable parameters are derived by analyzing the identifiability characteristics of the robot. We further show that any SLMBSS designed with Variable Configurations Joint allows all IPs to be identifiable through comparing two successive identification outcomes. This feature paves the way to design new class of SLMBSS for which accurate identification of all IPs is at hand. Different case studies reveal that proposed formulation provides fast and accurate results, as required by the space applications. Further studies might be necessary for cases where planar-body assumption becomes inaccurate.

Hype and public trust in science.

PubMed

Master, Zubin; Resnik, David B

2013-06-01

Social scientists have begun elucidating the variables that influence public trust in science, yet little is known about hype in biotechnology and its effects on public trust. Many scholars claim that hyping biotechnology results in a loss of public trust, and possibly public enthusiasm or support for science, because public expectations of the biotechnological promises will be unmet. We argue for the need for empirical research that examines the relationships between hype, public trust, and public enthusiasm/support. We discuss the complexities in designing empirical studies that provide evidence for a causal link between hype, public trust, and public enthusiasm/support, but also illustrate how this may be remedied. Further empirical research on hype and public trust is needed in order to improve public communication of science and to design evidence-based education on the responsible conduct of research for scientists. We conclude that conceptual arguments made on hype and public trust must be nuanced to reflect our current understanding of this relationship.

Hype and Public Trust in Science

PubMed Central

Resnik, David B.

2014-01-01

Social scientists have begun elucidating the variables that influence public trust in science, yet little is known about hype in biotechnology and its effects on public trust. Many scholars claim that hyping biotechnology results in a loss of public trust, and possibly public enthusiasm or support for science, because public expectations of the biotechnological promises will be unmet. We argue for the need for empirical research that examines the relationships between hype, public trust, and public enthusiasm/support. We discuss the complexities in designing empirical studies that provide evidence for a causal link between hype, public trust, and public enthusiasm/support, but also illustrate how this may be remedied. Further empirical research on hype and public trust is needed in order to improve public communication of science and to design evidence-based education on the responsible conduct of research for scientists. We conclude that conceptual arguments made on hype and public trust must be nuanced to reflect our current understanding of this relationship. PMID:22045550

Automated geo/ortho registered aerial imagery product generation using the mapping system interface card (MSIC)

NASA Astrophysics Data System (ADS)

Bratcher, Tim; Kroutil, Robert; Lanouette, André; Lewis, Paul E.; Miller, David; Shen, Sylvia; Thomas, Mark

2013-05-01

The development concept paper for the MSIC system was first introduced in August 2012 by these authors. This paper describes the final assembly, testing, and commercial availability of the Mapping System Interface Card (MSIC). The 2.3kg MSIC is a self-contained, compact variable configuration, low cost real-time precision metadata annotator with embedded INS/GPS designed specifically for use in small aircraft. The MSIC was specifically designed to convert commercial-off-the-shelf (COTS) digital cameras and imaging/non-imaging spectrometers with Camera Link standard data streams into mapping systems for airborne emergency response and scientific remote sensing applications. COTS digital cameras and imaging/non-imaging spectrometers covering the ultraviolet through long-wave infrared wavelengths are important tools now readily available and affordable for use by emergency responders and scientists. The MSIC will significantly enhance the capability of emergency responders and scientists by providing a direct transformation of these important COTS sensor tools into low-cost real-time aerial mapping systems.

High spatial variability of carbon dioxide and methane emission in three tropical reservoirs

NASA Astrophysics Data System (ADS)

Reinaldo Paranaiba, José; Barros, Nathan O.; Mendonça, Raquel F.; Linkhorst, Annika; Isidorova, Anastasija; Roland, Fabio; Sobek, Sebastian

2017-04-01

In the tropics, many new large hydropower dams are being built, in order to produce renewable energy for economic growth. Most inland waters, such as rivers, lakes and reservoirs, emit greenhouse gases to the atmosphere, and especially tropical reservoirs have been pointed out as strong sources of methane. However, present estimates of greenhouse gas emission from reservoirs are limited by the amount of available data. In particular, the spatial variability of greenhouse gas emission from reservoirs is insufficiently understood. In order to test the hypothesis that the diffusive emission of carbon dioxide (CO2) and methane (CH4) from tropical reservoirs is characterized by strong spatial variability and incorrectly represented by measurements at one site only, we studied three reservoirs situated in different tropical climates, during the dry period. We conducted spatially resolved measurements of surface water concentrations of dissolved carbon dioxide and methane using an on-line equilibration system, as well as of the gas exchange velocity using floating chambers. We found pronounced spatial variability of diffusive CO2 and CH4 emission in all three reservoirs. River inflow areas were more likely to have high concentrations of particularly CH4, but also CO2, than other areas in the reservoirs. Close to the dam, CH4 concentrations were comparatively low in each reservoir. The variability of CH4 concentration was linked to geographical position, which we ascribe to hot spots of methanogenesis at sites of high sediment deposition, such as river inflow areas. The variability of CO2 concentration seemed instead rather to be linked to in-situ metabolism. Also the gas exchange velocity varied pronouncedly in each reservoir, but without any detectable systematic patterns, calling for further studies. We conclude that accurate upscaling of reservoir greenhouse gas emissions requires accounting for within-reservoir spatial variability, and that the anthropogenic increase of sediment flux from catchments to downstream reservoirs may be linked to increased reservoir CH4 emission.

Illegitimate Tasks as an Impediment to Job Satisfaction and Intrinsic Motivation: Moderated Mediation Effects of Gender and Effort-Reward Imbalance

PubMed Central

Omansky, Rachel; Eatough, Erin M.; Fila, Marcus J.

2016-01-01

The current work examines a contemporary workplace stressor that has only recently been introduced into the literature: illegitimate tasks. Illegitimate tasks are work tasks that violate identity role norms about what can reasonably be expected from an employee in a given position. Although illegitimate tasks have been linked to employee well-being in past work, we know little about the potential explanatory mechanisms linking illegitimate tasks to work-relevant negative psychological states. Using a sample of 213 US-based employees of mixed occupations and a cross-sectional design, the present study examines job satisfaction and intrinsic motivation as outcomes of illegitimate tasks. Additionally, we examine perception of effort-reward imbalance (ERI) as a potential mediating mechanism through which illegitimate tasks relate to job satisfaction and intrinsic motivation, highlighting a possible pathway by which these relationships are functioning. Finally, we explore gender as a socially constructed variable that could contribute to variation in responses to illegitimate tasks and moderate the mediated link between illegitimate tasks and outcomes. Results indicated that illegitimate tasks were significantly related to job satisfaction and intrinsic motivation both directly and indirectly through perceptions of ERI in the predicted directions. Moreover, a moderated-mediation effect was found such that male workers reacted more than female workers to illegitimate tasks through the mechanism of perceived ERI. PMID:27917145

Illegitimate Tasks as an Impediment to Job Satisfaction and Intrinsic Motivation: Moderated Mediation Effects of Gender and Effort-Reward Imbalance.

PubMed

Omansky, Rachel; Eatough, Erin M; Fila, Marcus J

2016-01-01

The current work examines a contemporary workplace stressor that has only recently been introduced into the literature: illegitimate tasks. Illegitimate tasks are work tasks that violate identity role norms about what can reasonably be expected from an employee in a given position. Although illegitimate tasks have been linked to employee well-being in past work, we know little about the potential explanatory mechanisms linking illegitimate tasks to work-relevant negative psychological states. Using a sample of 213 US-based employees of mixed occupations and a cross-sectional design, the present study examines job satisfaction and intrinsic motivation as outcomes of illegitimate tasks. Additionally, we examine perception of effort-reward imbalance (ERI) as a potential mediating mechanism through which illegitimate tasks relate to job satisfaction and intrinsic motivation, highlighting a possible pathway by which these relationships are functioning. Finally, we explore gender as a socially constructed variable that could contribute to variation in responses to illegitimate tasks and moderate the mediated link between illegitimate tasks and outcomes. Results indicated that illegitimate tasks were significantly related to job satisfaction and intrinsic motivation both directly and indirectly through perceptions of ERI in the predicted directions. Moreover, a moderated-mediation effect was found such that male workers reacted more than female workers to illegitimate tasks through the mechanism of perceived ERI.

[Clustering patterns of behavioral risk factors linked to chronic disease among young adults in two localities in Bogota, Colombia: importance of sex differences].

PubMed

Gómez Gutiérrez, Luis Fernando; Lucumí Cuesta, Diego Iván; Girón Vargas, Sandra Lorena; Espinosa García, Gladys

2004-01-01

The characterization of clustering behavioral risk factors may be used as a guideline for interventions aimed at preventing chronic diseases. This study determined the clustering patterns of some behavioral risk factors in young adults aged 18 to 29 years and established the factors associated with having two or more of them. Patterns of clustering by gender were established in four behavioral risk factors (low consumption of fruits and vegetables, physical inactivity in leisure time, current tobacco consumption and acute alcohol consumption), in 1465 young adults participants through a multistage probabilistic sample. Regression models identified the sociodemografic variables associated with having two or more of the aforementioned behavioral risk factors. Having one, 32.9% two and 17.7% three or four. Acute alcohol consumption was the risk factor most frequent in the combined risk factor patterns among males; physical inactivity during leisure time being the most frequent among females. Among the females, having two or more behavioral risk factors was linked to be separated or divorced, this having been linked to work having been the main activity over the past 30 days among males. The combinations of behavioral risk factors studied and the factors associated with clustering show different patterns among males and females. These findings stressed the need of designing interventions sensitive to gender differences.

Instrument Selection for Randomized Controlled Trials Why This and Not That?

PubMed Central

Records, Kathie; Keller, Colleen; Ainsworth, Barbara; Permana, Paska

2011-01-01

A fundamental linchpin for obtaining rigorous findings in quantitative research involves the selection of survey instruments. Psychometric recommendations are available for the processes for scale development and testing and guidance for selection of established scales. These processes are necessary to address the validity link between the phenomena under investigation, the empirical measures and, ultimately, the theoretical ties between these and the world views of the participants. Detailed information is most often provided about study design and protocols, but far less frequently is a detailed theoretical explanation provided for why specific instruments are chosen. Guidance to inform choices is often difficult to find when scales are needed for specific cultural, ethnic, or racial groups. This paper details the rationale underlying instrument selection for measurement of the major processes (intervention, mediator and moderator variables, outcome variables) in an ongoing study of postpartum Latinas, Madres para la Salud [Mothers for Health]. The rationale underpinning our choices includes a discussion of alternatives, when appropriate. These exemplars may provide direction for other intervention researchers who are working with specific cultural, racial, or ethnic groups or for other investigators who are seeking to select the ‘best’ instrument. Thoughtful consideration of measurement and articulation of the rationale underlying our choices facilitates the maintenance of rigor within the study design and improves our ability to assess study outcomes. PMID:21986392

Supervised artificial neural network-based method for conversion of solar radiation data (case study: Algeria)

NASA Astrophysics Data System (ADS)

Laidi, Maamar; Hanini, Salah; Rezrazi, Ahmed; Yaiche, Mohamed Redha; El Hadj, Abdallah Abdallah; Chellali, Farouk

2017-04-01

In this study, a backpropagation artificial neural network (BP-ANN) model is used as an alternative approach to predict solar radiation on tilted surfaces (SRT) using a number of variables involved in physical process. These variables are namely the latitude of the site, mean temperature and relative humidity, Linke turbidity factor and Angstrom coefficient, extraterrestrial solar radiation, solar radiation data measured on horizontal surfaces (SRH), and solar zenith angle. Experimental solar radiation data from 13 stations spread all over Algeria around the year (2004) were used for training/validation and testing the artificial neural networks (ANNs), and one station was used to make the interpolation of the designed ANN. The ANN model was trained, validated, and tested using 60, 20, and 20 % of all data, respectively. The configuration 8-35-1 (8 inputs, 35 hidden, and 1 output neurons) presented an excellent agreement between the prediction and the experimental data during the test stage with determination coefficient of 0.99 and root meat squared error of 5.75 Wh/m2, considering a three-layer feedforward backpropagation neural network with Levenberg-Marquardt training algorithm, a hyperbolic tangent sigmoid and linear transfer function at the hidden and the output layer, respectively. This novel model could be used by researchers or scientists to design high-efficiency solar devices that are usually tilted at an optimum angle to increase the solar incident on the surface.

Linking Data for Mothers and Babies in De-Identified Electronic Health Data.

PubMed

Harron, Katie; Gilbert, Ruth; Cromwell, David; van der Meulen, Jan

2016-01-01

Linkage of longitudinal administrative data for mothers and babies supports research and service evaluation in several populations around the world. We established a linked mother-baby cohort using pseudonymised, population-level data for England. Retrospective linkage study using electronic hospital records of mothers and babies admitted to NHS hospitals in England, captured in Hospital Episode Statistics between April 2001 and March 2013. Of 672,955 baby records in 2012/13, 280,470 (42%) linked deterministically to a maternal record using hospital, GP practice, maternal age, birthweight, gestation, birth order and sex. A further 380,164 (56%) records linked using probabilistic methods incorporating additional variables that could differ between mother/baby records (admission dates, ethnicity, 3/4-character postcode district) or that include missing values (delivery variables). The false-match rate was estimated at 0.15% using synthetic data. Data quality improved over time: for 2001/02, 91% of baby records were linked (holding the estimated false-match rate at 0.15%). The linked cohort was representative of national distributions of gender, gestation, birth weight and maternal age, and captured approximately 97% of births in England. Probabilistic linkage of maternal and baby healthcare characteristics offers an efficient way to enrich maternity data, improve data quality, and create longitudinal cohorts for research and service evaluation. This approach could be extended to linkage of other datasets that have non-disclosive characteristics in common.

Space-time variability of raindrop size distributions along a 2.2 km microwave link path

NASA Astrophysics Data System (ADS)

van Leth, Tommy; Uijlenhoet, Remko; Overeem, Aart; Leijnse, Hidde; Berne, Alexis

2017-04-01

The Wageningen Urban Rainfall Experiment (WURex14-15) was dedicated to address several errors and uncertainties associated with quantitative precipitation estimates from microwave links. The core of the experiment consisted of three co-located microwave links installed between two major buildings on the Wageningen University campus, approximately 2.2 km apart: a 38 GHz commercial microwave link, provided by T-Mobile NL, and 26 GHz and 38 GHz (dual-polarization) research microwave links from RAL. Transmitting and receiving antennas were attached to masts installed on the roofs of the two buildings, about 30 m above the ground. This setup was complemented with a Scintec infrared Large-Aperture Scintillometer, installed over the same path, an automatic rain gauge, as well as 5 Parsivel optical disdrometers positioned at several locations along the path. Temporal sampling of the received signals was performed at a rate of 20 Hz. The setup was being monitored by time-lapse cameras to assess the state of the antennas as well as the atmosphere. Finally, data were available from the KNMI weather radars and an automated weather station situated just outside Wageningen. The experiment has been active between August 2014 and December 2015. We present preliminary results regarding the space-time variability of raindrop size distributions from the Parsivel disdrometers along the 2.2 km microwave link path.

Exploring the links between macro-level contextual factors and their influence on nursing workforce composition.

PubMed

Squires, Allison; Beltrán-Sánchez, Hiram

2011-11-01

Research that links macro-level socioeconomic development variables to health care human resources workforce composition is scarce at best. The purpose of this study was to explore the links between nonnursing factors and nursing workforce composition through a secondary, descriptive analysis of year 2000, publicly available national nursing human resources data from Mexico. Building on previous research, the authors conducted multiple robust regression analysis by federal typing of nursing human resources from 31 Mexican states against macro-level socioeconomic development variables. Average education in a state was significantly associated in predicting all types of formally educated nurses in Mexico. Other results suggest that macro-level indicators have a different association with each type of nurse. Context may play a greater role in determining nursing workforce composition than previously thought. Further studies may help to explain differences both within and between countries.

Exploring the Links Between Macro-Level Contextual Factors and Their Influence on Nursing Workforce Composition

PubMed Central

Squires, Allison; Beltrán-Sánchez, Hiram

2012-01-01

Research that links macro-level socioeconomic development variables to healthcare human resources workforce composition is scarce at best. The purpose of this study was to explore the links between non-nursing factors and nursing workforce composition through a secondary, descriptive analysis of year 2000, publicly available national nursing human resources data from Mexico. Building on previous research, the authors conducted multiple robust regression analysis by federal typing of nursing human resources from 31 Mexican states against macro-level socioeconomic development variables. Average education in a state was significantly associated in predicting all types of formally educated nurses in Mexico. Other results suggest that macro level indicators have a different association with each type of nurse. Context may play a greater role in determining nursing workforce composition than previously thought. Further studies may help to explain differences both within and between countries. PMID:22513839

Does Variability Across Events Affect Verb Learning in English, Mandarin and Korean?

PubMed Central

Childers, Jane B.; Paik, Jae H.; Flores, Melissa; Lai, Gabrielle; Dolan, Megan

2016-01-01

Extending new verbs is important to becoming a productive speaker of a language. Prior results show children have difficulty extending verbs when they have seen events with varied agents. This paper further examines the impact of variability on verb learning, and asks whether this interacts with event complexity or differs by language. Children (aged 2 ½- to 3-years) in the U.S., China, Korea and Singapore learned verbs linked to simple and complex events. Sets of events included one or three agents, and children were asked to extend the verb at test. Children learning verbs linked to simple movements performed similarly across conditions. However, children learning verbs linked to events with multiple objects were less successful if those events were enacted by multiple agents. A follow-up study rules out an influence of event order. Overall, similar patterns of results emerged across languages, suggesting common cognitive processes support children’s verb learning. PMID:27457679

Intra- and Inter-Individual Variation in Self-Reported Code-Switching Patterns of Adult Multilinguals

ERIC Educational Resources Information Center

Dewaele, Jean-Marc; Li, Wei

2014-01-01

The present study is a large-scale quantitative analysis of intra-individual variation (linked to type of interlocutor) and inter-individual variation (linked to multilingualism, sociobiographical variables and three personality traits) in self-reported frequency of code-switching (CS) among 2116 multilinguals. We found a significant effect of…

Does Sensitivity to Magnitude Depend on the Temporal Distribution of Reinforcement?

ERIC Educational Resources Information Center

Grace, Randolph C.; Bragason, Orn

2005-01-01

Our research addressed the question of whether sensitivity to relative reinforcer magnitude in concurrent chains depends on the distribution of reinforcer delays when the terminal-link schedules are equal. In Experiment 1, 12 pigeons responded in a two-component procedure. In both components, the initial links were concurrent variable-interval 40…

Using non-systematic surveys to investigate effects of regional climate variability on Australasian gannets in the Hauraki Gulf, New Zealand

NASA Astrophysics Data System (ADS)

Srinivasan, Mridula; Dassis, Mariela; Benn, Emily; Stockin, Karen A.; Martinez, Emmanuelle; Machovsky-Capuska, Gabriel E.

2015-05-01

Few studies have investigated regional and natural climate variability on seabird populations using ocean reanalysis datasets (e.g. Simple Ocean Data Assimilation (SODA)) that integrate atmospheric information to supplement ocean observations and provide improved estimates of ocean conditions. Herein we use a non-systematic dataset on Australasian gannets (Morus serrator) from 2001 to 2009 to identify potential connections between Gannet Sightings Per Unit Effort (GSPUE) and climate and oceanographic variability in a region of known importance for breeding seabirds, the Hauraki Gulf (HG), New Zealand. While no statistically significant relationships between GSPUE and global climate indices were determined, there was a significant correlation between GSPUE and regional SST anomaly for HG. Also, there appears to be a strong link between global climate indices and regional climate in the HG. Further, based on cross-correlation function coefficients and lagged multiple regression models, we identified potential leading and lagging climate variables, and climate variables but with limited predictive capacity in forecasting future GSPUE. Despite significant inter-annual variability and marginally cooler SSTs since 2001, gannet sightings appear to be increasing. We hypothesize that at present underlying physical changes in the marine ecosystem may be insufficient to affect supply of preferred gannet main prey (pilchard Sardinops spp.), which tolerate a wide thermal range. Our study showcases the potential scientific value of lengthy non-systematic data streams and when designed properly (i.e., contain abundance, flock size, and spatial data), can yield useful information in climate impact studies on seabirds and other marine fauna. Such information can be invaluable for enhancing conservation measures for protected species in fiscally constrained research environments.

Learning Across Time Scales: Science, Policy, Management, and Communication

NASA Astrophysics Data System (ADS)

Stewart, M. M.

2002-05-01

This presentation will draw together common themes raised in the session and discuss lessons learned across time scales and their implications for managers and policy makers concerned with both climate change and variability. Session themes will be examined in the context of the upcoming World Summit on Sustainable Development (WSSD) and considered as opportunities for linking climate change policy discussions with lessons learned from the study of adaptation on seasonal to interannual time scales. The presentation will raise questions about future research directions, discuss recommendations for promoting learning across time scales, and explore options for better communicating the links between climate change and variability.

Variable links within perceived police legitimacy?: fairness and effectiveness across races and places.

PubMed

Taylor, Ralph B; Wyant, Brian R; Lockwood, Brian

2015-01-01

This work examines connections between two threads of community residents' perceptions of local police legitimacy, effectiveness and procedural fairness, and how those links depend on race, place, and race/place combinations. Previous works have connected these two threads, but have failed (a) to explore the variability of that connection by race, place, and race/place combinations across communities spanning the urban to suburban to rural continuum or (b) to model mutual influence. An extension of the group position thesis and work on minority views of police practices suggest how these variations might be patterned. Data were derived from a 2003 probability-based sampling survey of household respondents across Pennsylvania (n=1289). Generalized confirmatory factor analysis models built procedural fairness and effectiveness indices for four groups: whites in urban core counties, non-whites in urban core counties, whites in non-urban core counties, and non-whites in non-urban core counties. Non-recursive structural equation models revealed variable impacts of perceived police effectiveness on perceived police fairness and, to a lesser extent, of fairness on effectiveness. Implications for a more structurally and contextually aware understanding of links in police legitimacy models are developed. Copyright © 2014 Elsevier Inc. All rights reserved.

Cloud cover anomalies at middle latitudes: Links to troposphere dynamics and solar variability

NASA Astrophysics Data System (ADS)

Veretenenko, S.; Ogurtsov, M.

2016-11-01

In this work we study links between low cloud anomalies (LCA) at middle latitudes of the Northern and Southern hemispheres and galactic cosmic ray (GCR) variations used as a proxy of solar variability on the decadal time scale. It was shown that these links are not direct, but realized through GCR/solar activity phenomena influence on the development of extratropical baric systems (cyclones and troughs) which form cloud field. The violation of a positive correlation between LCA and GCR intensity which was observed in the 1980s-1990s occurred simultaneously in the Northern and Southern hemispheres in the early 2000s and coincided with the sign reversal of GCR effects on troposphere circulation. It was suggested that a possible reason for the correlation reversal between cyclonic activity at middle latitudes and GCR fluxes is the change of the stratospheric polar vortex intensity which influences significantly the troposphere-stratosphere coupling. The evidences for a noticeable weakening of the polar vortices in the Arctic and Antarctic stratosphere in the early 2000s are provided. The results obtained suggest an important role of the polar vortex evolution as a reason for a temporal variability of solar activity effects on the lower atmosphere.

Teleconnected ocean forcing of Western North American droughts and pluvials during the last millennium

USGS Publications Warehouse

Routson, Cody C.; Woodhouse, Connie A.; Overpeck, Jonathan T.; Betancourt, Julio L.; McKay, Nicholas P.

2016-01-01

Western North America (WNA) is rich in hydroclimate reconstructions, yet questions remain about the causes of decadal-to-multidecadal hydroclimate variability. Teleconnection patterns preserved in annually-resolved tree-ring reconstructed drought maps, and anomalies in a global network of proxy sea surface temperature (SST) reconstructions, were used to reassess the evidence linking ocean forcing to WNA hydroclimate variability over the past millennium. Potential forcing mechanisms of the Medieval Climate Anomaly (MCA) and individual drought and pluvial events—including two multidecadal-length MCA pluvials—were evaluated. We show strong teleconnection patterns occurred during the driest (wettest) years within persistent droughts (pluvials), implicating SSTs as a potent hydroclimate forcing mechanism. The role of the SSTs on longer timescales is more complex. Pacific teleconnection patterns show little long-term change, whereas low-resolution SST reconstructions vary over decades to centuries. While weaker than the tropical Pacific teleconnections, North Atlantic teleconnection patterns and SST reconstructions also show links to WNA droughts and pluvials, and may in part account for longer-term WNA hydroclimate changes. Nonetheless, evidence linking WNA hydroclimate to SSTs still remains sparse and nuanced—especially over long-timescales with a broader range of hydroclimatic variability than characterized during the 20th century.

T-wave alternans and beat-to-beat variability of repolarization: pathophysiological backgrounds and clinical relevance.

PubMed

Floré, Vincent; Willems, Rik

2012-12-01

In this review, we focus on temporal variability of cardiac repolarization. This phenomenon has been related to a higher risk for ventricular arrhythmia and is therefore interesting as a marker of sudden cardiac death risk. We review two non-invasive clinical techniques quantifying repolarization variability: T-wave alternans (TWA) and beat-to-beat variability of repolarization (BVR). We discuss their pathophysiological link with ventricular arrhythmia and the current clinical relevance of these techniques.

EEE Links, Volume 9, No. 1, January 2003 Focus on Plastic Parts

NASA Technical Reports Server (NTRS)

2003-01-01

The January 2003 issue of Electronic, Electromechanical, Electric (EEE) Links is presented. The Programmable Logic Application Notes column has been reinstated in this newsletter. Written by Rich Katz of NASA's Office of Logic Design (OLD), the application notes offer technical tips intended to prevent flight design errors and enhance research, development, and use of programmable logic and elements for space flight applications. An archive of these notes columns from previous issues of EEE Links is available at http://www.klabs.org/richcontent/eeelink s/EEE Links.htm.

Is case-specificity content-specificity? An analysis of data from extended-matching questions.

PubMed

Dory, Valerie; Gagnon, Robert; Charlin, Bernard

2010-03-01

Case-specificity, i.e., variability of a subject's performance across cases, has been a consistent finding in medical education. It has important implications for assessment validity and reliability. Its root causes remain a matter of discussion. One hypothesis, content-specificity, links variability of performance to variable levels of relevant knowledge. Extended-matching items (EMIs) are an ideal format to test this hypothesis as items are grouped by topic. If differences pertaining to content knowledge are the main cause of case-specificity, variability across topics should be high and variability across items within the same topic low. We used generalisability analysis on results of a written test composed of 159 EMIs sat by two cohorts of general practice trainees at one university. Two hundred and twenty-seven trainees took part. The variance component attributed to subjects was small. Variance attributed to topics was smaller than variance attributed to items. The main source of error was interaction between subjects and items, accounting for two-thirds of error. The generalisability D study revealed that for the same total number of items, increasing the number of topics results in a higher G coefficient than increasing the number of items per topic. Topical knowledge does not seem to explain case-specificity observed in our data. Structure of knowledge and reasoning strategy may be more important, in particular pattern-recognition which EMIs were designed to elicit. The causal explanations of case-specificity may be dependent on test format. Increasing the number of topics with fewer items each would increase reliability but also testing time.

Fractional Programming for Communication Systems—Part II: Uplink Scheduling via Matching

NASA Astrophysics Data System (ADS)

Shen, Kaiming; Yu, Wei

2018-05-01

This two-part paper develops novel methodologies for using fractional programming (FP) techniques to design and optimize communication systems. Part I of this paper proposes a new quadratic transform for FP and treats its application for continuous optimization problems. In this Part II of the paper, we study discrete problems, such as those involving user scheduling, which are considerably more difficult to solve. Unlike the continuous problems, discrete or mixed discrete-continuous problems normally cannot be recast as convex problems. In contrast to the common heuristic of relaxing the discrete variables, this work reformulates the original problem in an FP form amenable to distributed combinatorial optimization. The paper illustrates this methodology by tackling the important and challenging problem of uplink coordinated multi-cell user scheduling in wireless cellular systems. Uplink scheduling is more challenging than downlink scheduling, because uplink user scheduling decisions significantly affect the interference pattern in nearby cells. Further, the discrete scheduling variable needs to be optimized jointly with continuous variables such as transmit power levels and beamformers. The main idea of the proposed FP approach is to decouple the interaction among the interfering links, thereby permitting a distributed and joint optimization of the discrete and continuous variables with provable convergence. The paper shows that the well-known weighted minimum mean-square-error (WMMSE) algorithm can also be derived from a particular use of FP; but our proposed FP-based method significantly outperforms WMMSE when discrete user scheduling variables are involved, both in term of run-time efficiency and optimizing results.

[Association between stress and depression levels and treatment adherence among HIV-positive individuals in Hermosillo, México].

PubMed

Piña López, Julio Alfonso; Dávila Tapia, Mariana; Sánchez-Sosa, Juan José; Togawa, Carlos; Cázares Robles, Oscar

2008-06-01

To evaluate the association between variables related to stress, reasons, and depression, and adherence to treatment in HIV-positive individuals, and to analyze the robustness according to a theoretical psychology model. This was a cross-sectional study of 25 female and 39 male HIV-positive participants receiving services at the Outpatient Center for Prevention and Treatment of HIV/AIDS and Sexually-transmitted Diseases (Centro Ambulatorio para la Prevención y Atención del VIH/Sida e Infecciones de Transmisión Sexual) in Hermosillo, Sonora, Mexico. The psychological variables, the degree of treatment adherence, stress-related circumstances, and the severity of depression were examined. Rates were calculated for the key variables associated with stress, reasons, and depression. The associations among variables were determined by multiple regression. During the month preceding the study, 65.6% of the 64 participants reported having faithfully followed the prescribed treatment, while 34.4% had failed, in some way, to follow the treatment (chi(2) = 6.250; P = 0.012). Regression analysis found that there was only one combination, an intermediate level of stress linked to tolerance of uncertainty and low levels of depression, that was significantly associated (F [3.58] = 3.298; P = 0.027) with adherence to treatment; the combination of these two variables explained 38.2% of the total variance found. The combination of stress levels with tolerance of uncertainty and depression could be used as a predictor for true compliance with prescribed treatment plans. These results should be taken into account when designing intervention and treatment-adherence campaigns in HIV-positive individuals.

Nonlinear Optics Technology. Phase 3. Volume 2. Phase Conjugated Optical Communication Link

DTIC Science & Technology

1991-01-12

experiments and mechanical design of the artificial turbulence generator (turbox), Dr. George M. Harpole who provided the technical design of the turbox, Dr...understanding of FWM PC comm link physics and to determine design requirements for a fieldable system. The system model demonstrated that phase...using photorefractive material was also designed , fabricated, and characterized. The efficiency of heterodyne mixing of an aberrated beacon beam was

Mating behavior and the evolution of sperm design

PubMed Central

Schärer, Lukas; Littlewood, D. Timothy J.; Waeschenbach, Andrea; Yoshida, Wataru; Vizoso, Dita B.

2011-01-01

Sperm are the most diverse of all animal cell types, and much of the diversity in sperm design is thought to reflect adaptations to the highly variable conditions under which sperm function and compete to achieve fertilization. Recent work has shown that these conditions often evolve rapidly as a consequence of multiple mating, suggesting a role for sexual selection and sexual conflict in the evolution of sperm design. However, very little of the striking diversity in sperm design is understood functionally, particularly in internally fertilizing organisms. We use phylogenetic comparative analyses covering 16 species of the hermaphroditic flatworm genus Macrostomum to show that a complex sperm design is associated with reciprocal mating and that this complexity is lost secondarily when hypodermic insemination—sperm injection through the epidermis—evolves. Specifically, the complex sperm design, which includes stiff lateral bristles, is likely a male persistence trait associated with sexual conflicts over the fate of received ejaculates and linked to female resistance traits, namely an intriguing postcopulatory sucking behavior and a thickened epithelium of the sperm-receiving organ. Our results suggest that the interactions between sperm donor, sperm, and sperm recipient can change drastically when hypodermic insemination evolves, involving convergent evolution of a needle-like copulatory organ, a simpler sperm design, and a simpler female genital morphology. Our study documents that a shift in the mating behavior may alter fundamentally the conditions under which sperm compete and thereby lead to a drastic change in sperm design. PMID:21220334

Indian Summer Monsoon Rainfall: Implications of Contrasting Trends in the Spatial Variability of Means and Extremes

PubMed Central

Ghosh, Subimal; Vittal, H.; Sharma, Tarul; Karmakar, Subhankar; Kasiviswanathan, K. S.; Dhanesh, Y.; Sudheer, K. P.; Gunthe, S. S.

2016-01-01

India’s agricultural output, economy, and societal well-being are strappingly dependent on the stability of summer monsoon rainfall, its variability and extremes. Spatial aggregate of intensity and frequency of extreme rainfall events over Central India are significantly increasing, while at local scale they are spatially non-uniform with increasing spatial variability. The reasons behind such increase in spatial variability of extremes are poorly understood and the trends in mean monsoon rainfall have been greatly overlooked. Here, by using multi-decadal gridded daily rainfall data over entire India, we show that the trend in spatial variability of mean monsoon rainfall is decreasing as exactly opposite to that of extremes. The spatial variability of extremes is attributed to the spatial variability of the convective rainfall component. Contrarily, the decrease in spatial variability of the mean rainfall over India poses a pertinent research question on the applicability of large scale inter-basin water transfer by river inter-linking to address the spatial variability of available water in India. We found a significant decrease in the monsoon rainfall over major water surplus river basins in India. Hydrological simulations using a Variable Infiltration Capacity (VIC) model also revealed that the water yield in surplus river basins is decreasing but it is increasing in deficit basins. These findings contradict the traditional notion of dry areas becoming drier and wet areas becoming wetter in response to climate change in India. This result also calls for a re-evaluation of planning for river inter-linking to supply water from surplus to deficit river basins. PMID:27463092

Indian Summer Monsoon Rainfall: Implications of Contrasting Trends in the Spatial Variability of Means and Extremes.

PubMed

Ghosh, Subimal; Vittal, H; Sharma, Tarul; Karmakar, Subhankar; Kasiviswanathan, K S; Dhanesh, Y; Sudheer, K P; Gunthe, S S

2016-01-01

India's agricultural output, economy, and societal well-being are strappingly dependent on the stability of summer monsoon rainfall, its variability and extremes. Spatial aggregate of intensity and frequency of extreme rainfall events over Central India are significantly increasing, while at local scale they are spatially non-uniform with increasing spatial variability. The reasons behind such increase in spatial variability of extremes are poorly understood and the trends in mean monsoon rainfall have been greatly overlooked. Here, by using multi-decadal gridded daily rainfall data over entire India, we show that the trend in spatial variability of mean monsoon rainfall is decreasing as exactly opposite to that of extremes. The spatial variability of extremes is attributed to the spatial variability of the convective rainfall component. Contrarily, the decrease in spatial variability of the mean rainfall over India poses a pertinent research question on the applicability of large scale inter-basin water transfer by river inter-linking to address the spatial variability of available water in India. We found a significant decrease in the monsoon rainfall over major water surplus river basins in India. Hydrological simulations using a Variable Infiltration Capacity (VIC) model also revealed that the water yield in surplus river basins is decreasing but it is increasing in deficit basins. These findings contradict the traditional notion of dry areas becoming drier and wet areas becoming wetter in response to climate change in India. This result also calls for a re-evaluation of planning for river inter-linking to supply water from surplus to deficit river basins.

Insulin resistance and carotid intima-media thickness mediate the association between resting-state heart rate variability and executive function: A path modelling study.

PubMed

Kemp, Andrew H; López, Santiago Rodríguez; Passos, Valeria M A; Bittencourt, Marcio S; Dantas, Eduardo M; Mill, José G; Ribeiro, Antonio L P; Thayer, Julian F; Bensenor, Isabela M; Lotufo, Paulo A

2016-05-01

Research has linked high-frequency heart rate variability (HF-HRV) to cognitive function. The present study adopts a modern path modelling approach to understand potential causal pathways that may underpin this relationship. Here we examine the association between resting-state HF-HRV and executive function in a large sample of civil servants from Brazil (N=8114) recruited for the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). HF-HRV was calculated from 10-min resting-state electrocardiograms. Executive function was assessed using the trail-making test (version B). Insulin resistance (a marker of type 2 diabetes mellitus) and carotid intima-media thickness (subclinical atherosclerosis) mediated the relationship between HRV and executive function in seriatim. A limitation of the present study is its cross-sectional design; therefore, conclusions must be confirmed in longitudinal study. Nevertheless, findings support that possibility that HRV provides a 'spark' that initiates a cascade of adverse downstream effects that subsequently leads to cognitive impairment. Copyright © 2016 Elsevier B.V. All rights reserved.

Flight responses by a migratory soaring raptor to changing meteorological conditions.

PubMed

Lanzone, Michael J; Miller, Tricia A; Turk, Philip; Brandes, David; Halverson, Casey; Maisonneuve, Charles; Tremblay, Junior; Cooper, Jeff; O'Malley, Kieran; Brooks, Robert P; Katzner, Todd

2012-10-23

Soaring birds that undertake long-distance migration should develop strategies to minimize the energetic costs of endurance flight. This is relevant because condition upon completion of migration has direct consequences for fecundity, fitness and thus, demography. Therefore, strong evolutionary pressures are expected for energy minimization tactics linked to weather and topography. Importantly, the minute-by-minute mechanisms birds use to subsidize migration in variable weather are largely unknown, in large part because of the technological limitations in studying detailed long-distance bird flight. Here, we show golden eagle (Aquila chrysaetos) migratory response to changing meteorological conditions as monitored by high-resolution telemetry. In contrast to expectations, responses to meteorological variability were stereotyped across the 10 individuals studied. Eagles reacted to increased wind speed by using more orographic lift and less thermal lift. Concomitantly, as use of thermals decreased, variation in flight speed and altitude also decreased. These results demonstrate how soaring migrant birds can minimize energetic expenditures, they show the context for avian decisions and choices of specific instantaneous flight mechanisms and they have important implications for design of bird-friendly wind energy.

Characterization of the Physicochemical Properties of β-Cyclodextrin-Divinyl Sulfone Polymer Carrier-Bile Acid Systems.

PubMed

Mohamed, Mohamed H; Wang, Chen; Peru, Kerry M; Headley, John V; Wilson, Lee D

2017-08-07

Herein, we report on the systematic design and characterization of cross-linked polymer carriers containing β-cyclodextrin (β-CD) and divinyl sulfone (DVS). The polymer carriers were prepared at variable feed ratios (β-CD-DVS; 1:1, 1:2, 1:3, and 1:6) and characterized using spectroscopy (IR, 1 H solution NMR, and 13 C CP-MAS solids NMR spectroscopy), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and a dye decolorization method using phenolphthalein. Uptake studies were carried out at pH 9.00 for the polymer carriers using single component bile acids (cholic acid, deoxycholic acid, glycodeoxycholic acid, and taurodeoxycholic acid). Equilibrium uptake results were evaluated by the Langmuir isotherm model where variable equilibrium parameters were related to the relative apolar character of the bile acid. The Langmuir model yields a carrier/bile acid binding affinity of ∼10 3 M -1 where the lipophilic inclusion sites of the polymer play a prominent role, while the DVS linker framework sites have a lower adsorption affinity, in accordance with the greater hydrophilic character of such sites.

Synthesis and characterization of retrograded starch nanoparticles through homogenization and miniemulsion cross-linking.

PubMed

Ding, Yongbo; Zheng, Jiong; Zhang, Fusheng; Kan, Jianquan

2016-10-20

A new and convenient route to synthesizing retrograded starch nanoparticles (RS3NPs) through homogenization combined with a water-in-oil miniemulsion cross-linking technique was developed. The RS3NPs were optimized using Box-Behnken experimental design. Homogenization pressure (X1), oil/water ratio (X2), and surfactant (X3) were selected as independent variables, whereas particle size was considered as a dependent variable. Results indicated that homogenization pressure was the main contributing variable for particle size. The optimum values for homogenization pressure, oil/water ratio, and surfactant were 30MPa, 9.34:1, and 2.54g, respectively, whereas the particle size was predicted to be 288.2 nm. Morphological, physical, chemical, and functional properties of the RS3NPs were the assessed. Scanning electron microscopy and dynamic light scattering images showed that RS3NP granules were broken down to size of about 222.2nm. X-ray diffraction results revealed a disruption in crystallinity. The RS3NPs exhibited a slight decrease in To, but Tp and Tc increased and narrowest Tc-To. The solubility and swelling power were also increased. New peaks at 1594.84 and 1403.65cm(-1) were observed in the FTIR graph. However, homogenization minimally influenced the antidigestibility of RS3NPs. The absorption properties improved, and the adsorption kinetic described the contact time on the adsorption of captopril onto RS3NPs. In vitro release experiment indicated that the drug was released as follows: 21% after 2h in SGF, 42.78% at the end of 8h (2h in SGF and 6h in SIF), and 92.55% after 12h in SCF. These findings may help better utilize RS3NP in biomedical applications as a drug delivery material. Copyright © 2016 Elsevier Ltd. All rights reserved.

Improving the value of clinical research through the use of Common Data Elements.

PubMed

Sheehan, Jerry; Hirschfeld, Steven; Foster, Erin; Ghitza, Udi; Goetz, Kerry; Karpinski, Joanna; Lang, Lisa; Moser, Richard P; Odenkirchen, Joanne; Reeves, Dianne; Rubinstein, Yaffa; Werner, Ellen; Huerta, Michael

2016-12-01

The use of Common Data Elements can facilitate cross-study comparisons, data aggregation, and meta-analyses; simplify training and operations; improve overall efficiency; promote interoperability between different systems; and improve the quality of data collection. A Common Data Element is a combination of a precisely defined question (variable) paired with a specified set of responses to the question that is common to multiple datasets or used across different studies. Common Data Elements, especially when they conform to accepted standards, are identified by research communities from variable sets currently in use or are newly developed to address a designated data need. There are no formal international specifications governing the construction or use of Common Data Elements. Consequently, Common Data Elements tend to be made available by research communities on an empiric basis. Some limitations of Common Data Elements are that there may still be differences across studies in the interpretation and implementation of the Common Data Elements, variable validity in different populations, and inhibition by some existing research practices and the use of legacy data systems. Current National Institutes of Health efforts to support Common Data Element use are linked to the strengthening of National Institutes of Health Data Sharing policies and the investments in data repositories. Initiatives include cross-domain and domain-specific resources, construction of a Common Data Element Portal, and establishment of trans-National Institutes of Health working groups to address technical and implementation topics. The National Institutes of Health is seeking to lower the barriers to Common Data Element use through greater awareness and encourage the culture change necessary for their uptake and use. As National Institutes of Health, other agencies, professional societies, patient registries, and advocacy groups continue efforts to develop and promote the responsible use of Common Data Elements, particularly if linked to accepted data standards and terminologies, continued engagement with and feedback from the research community will remain important. © The Author(s) 2016.

Building a high level sample processing and quality assessment model for biogeochemical measurements: a case study from the ocean acidification community

NASA Astrophysics Data System (ADS)

Thomas, R.; Connell, D.; Spears, T.; Leadbetter, A.; Burger, E. F.

2016-12-01

The scientific literature heavily features small-scale studies with the impact of the results extrapolated to regional/global importance. There are on-going initiatives (e.g. OA-ICC, GOA-ON, GEOTRACES, EMODNet Chemistry) aiming to assemble regional to global-scale datasets that are available for trend or meta-analyses. Assessing the quality and comparability of these data requires information about the processing chain from "sampling to spreadsheet". This provenance information needs to be captured and readily available to assess data fitness for purpose. The NOAA Ocean Acidification metadata template was designed in consultation with domain experts for this reason; the core carbonate chemistry variables have 23-37 metadata fields each and for scientists generating these datasets there could appear to be an ever increasing amount of metadata expected to accompany a dataset. While this provenance metadata should be considered essential by those generating or using the data, for those discovering data there is a sliding scale between what is considered discovery metadata (title, abstract, contacts, etc.) versus usage metadata (methodology, environmental setup, lineage, etc.), the split depending on the intended use of data. As part of the OA-ICC's activities, the metadata fields from the NOAA template relevant to the sample processing chain and QA criteria have been factored to develop profiles for, and extensions to, the OM-JSON encoding supported by the PROV ontology. While this work started focused on carbonate chemistry variable specific metadata, the factorization could be applied within the O&M model across other disciplines such as trace metals or contaminants. In a linked data world with a suitable high level model for sample processing and QA available, tools and support can be provided to link reproducible units of metadata (e.g. the standard protocol for a variable as adopted by a community) and simplify the provision of metadata and subsequent discovery.

Two-Stage Design Method for Enhanced Inductive Energy Transmission with Q-Constrained Planar Square Loops.

PubMed

Eteng, Akaa Agbaeze; Abdul Rahim, Sharul Kamal; Leow, Chee Yen; Chew, Beng Wah; Vandenbosch, Guy A E

2016-01-01

Q-factor constraints are usually imposed on conductor loops employed as proximity range High Frequency Radio Frequency Identification (HF-RFID) reader antennas to ensure adequate data bandwidth. However, pairing such low Q-factor loops in inductive energy transmission links restricts the link transmission performance. The contribution of this paper is to assess the improvement that is reached with a two-stage design method, concerning the transmission performance of a planar square loop relative to an initial design, without compromise to a Q-factor constraint. The first stage of the synthesis flow is analytical in approach, and determines the number and spacing of turns by which coupling between similar paired square loops can be enhanced with low deviation from the Q-factor limit presented by an initial design. The second stage applies full-wave electromagnetic simulations to determine more appropriate turn spacing and widths to match the Q-factor constraint, and achieve improved coupling relative to the initial design. Evaluating the design method in a test scenario yielded a more than 5% increase in link transmission efficiency, as well as an improvement in the link fractional bandwidth by more than 3%, without violating the loop Q-factor limit. These transmission performance enhancements are indicative of a potential for modifying proximity HF-RFID reader antennas for efficient inductive energy transfer and data telemetry links.

Non-Bayesian Inference: Causal Structure Trumps Correlation

ERIC Educational Resources Information Center

Bes, Benedicte; Sloman, Steven; Lucas, Christopher G.; Raufaste, Eric

2012-01-01

The study tests the hypothesis that conditional probability judgments can be influenced by causal links between the target event and the evidence even when the statistical relations among variables are held constant. Three experiments varied the causal structure relating three variables and found that (a) the target event was perceived as more…

Individualism-Collectivism: Links to Occupational Plans and Work Values

ERIC Educational Resources Information Center

Hartung, Paul J.; Fouad, Nadya A.; Leong, Frederick T. L.; Hardin, Erin E.

2010-01-01

Individualism-collectivism (IC) constitutes a cultural variable thought to influence a wide variety of variables including career planning and decision making. To examine this possibility, college students (216 women, 106 men, 64% racial-ethnic minorities) responded to measures of IC, occupational plans, and work values. Multivariate analysis of…

Centering Effects in HLM Level-1 Predictor Variables.

ERIC Educational Resources Information Center

Schumacker, Randall E.; Bembry, Karen

Research has suggested that important research questions can be addressed with meaningful interpretations using hierarchical linear modeling (HLM). The proper interpretation of results, however, is invariably linked to the choice of centering for the Level-1 predictor variables that produce the outcome measure for the Level-2 regression analysis.…

EXPOSURE TO CONCENTRATED AMBIENT PARTICLES IN DETROIT ALTERS HEART RATE VARIABILITY IN SPONTANEOUSLY HYPERTENSIVE RATS

EPA Science Inventory

Elevations in airborne particulate matter (PM) are linked to increased mortality and morbidity in humans with cardiopulmonary disease. Clinical studies show that PM is associated with altered heart rate variability (HRV) and suggests that loss of autonomic control may underlie ca...

Gender-Linked Perceptions and Causal Attributions of Female/Male Competencies.

ERIC Educational Resources Information Center

Major, Harriet; Plake, Barbara S.

Undergraduate students (N=518) rated graduate application materials for males or females applying to traditionally perceived masculine or feminine fields. Independent variables were rater's pro/anti feminism, sex of subject, sex of referent, sex of field, and sex of attributes. Dependent variables were academic competence, personal dynamics,…

Interaction Effects of Hypervideo Navigation Variables in College Students' Self-Regulated Learning

ERIC Educational Resources Information Center

Azmy, Nabil

2013-01-01

The purpose of this study is to investigate the question of whether the interaction effects of hypervideo navigation variables (navigation control and navigation links) would affect college students' self-regulated learning just after their learning from instructional hypervideo programs. Navigation control (free navigation or free navigation with…

Travel Time Estimation Using Freeway Point Detector Data Based on Evolving Fuzzy Neural Inference System.

PubMed

Tang, Jinjun; Zou, Yajie; Ash, John; Zhang, Shen; Liu, Fang; Wang, Yinhai

2016-01-01

Travel time is an important measurement used to evaluate the extent of congestion within road networks. This paper presents a new method to estimate the travel time based on an evolving fuzzy neural inference system. The input variables in the system are traffic flow data (volume, occupancy, and speed) collected from loop detectors located at points both upstream and downstream of a given link, and the output variable is the link travel time. A first order Takagi-Sugeno fuzzy rule set is used to complete the inference. For training the evolving fuzzy neural network (EFNN), two learning processes are proposed: (1) a K-means method is employed to partition input samples into different clusters, and a Gaussian fuzzy membership function is designed for each cluster to measure the membership degree of samples to the cluster centers. As the number of input samples increases, the cluster centers are modified and membership functions are also updated; (2) a weighted recursive least squares estimator is used to optimize the parameters of the linear functions in the Takagi-Sugeno type fuzzy rules. Testing datasets consisting of actual and simulated data are used to test the proposed method. Three common criteria including mean absolute error (MAE), root mean square error (RMSE), and mean absolute relative error (MARE) are utilized to evaluate the estimation performance. Estimation results demonstrate the accuracy and effectiveness of the EFNN method through comparison with existing methods including: multiple linear regression (MLR), instantaneous model (IM), linear model (LM), neural network (NN), and cumulative plots (CP).

Travel Time Estimation Using Freeway Point Detector Data Based on Evolving Fuzzy Neural Inference System

PubMed Central

Tang, Jinjun; Zou, Yajie; Ash, John; Zhang, Shen; Liu, Fang; Wang, Yinhai

2016-01-01

Travel time is an important measurement used to evaluate the extent of congestion within road networks. This paper presents a new method to estimate the travel time based on an evolving fuzzy neural inference system. The input variables in the system are traffic flow data (volume, occupancy, and speed) collected from loop detectors located at points both upstream and downstream of a given link, and the output variable is the link travel time. A first order Takagi-Sugeno fuzzy rule set is used to complete the inference. For training the evolving fuzzy neural network (EFNN), two learning processes are proposed: (1) a K-means method is employed to partition input samples into different clusters, and a Gaussian fuzzy membership function is designed for each cluster to measure the membership degree of samples to the cluster centers. As the number of input samples increases, the cluster centers are modified and membership functions are also updated; (2) a weighted recursive least squares estimator is used to optimize the parameters of the linear functions in the Takagi-Sugeno type fuzzy rules. Testing datasets consisting of actual and simulated data are used to test the proposed method. Three common criteria including mean absolute error (MAE), root mean square error (RMSE), and mean absolute relative error (MARE) are utilized to evaluate the estimation performance. Estimation results demonstrate the accuracy and effectiveness of the EFNN method through comparison with existing methods including: multiple linear regression (MLR), instantaneous model (IM), linear model (LM), neural network (NN), and cumulative plots (CP). PMID:26829639

Inter-level Scaffolding and Sequences of Representational Activities in Teaching a Chemical System with Graphical Simulations

NASA Astrophysics Data System (ADS)

Li, Na; Black, John B.

2016-10-01

Chemistry knowledge can be represented at macro-, micro- and symbolic levels, and learning a chemistry topic requires students to engage in multiple representational activities. This study focused on scaffolding for inter-level connection-making in learning chemistry knowledge with graphical simulations. We also tested whether different sequences of representational activities produced different student learning outcomes in learning a chemistry topic. A sample of 129 seventh graders participated in this study. In a simulation-based environment, participants completed three representational activities to learn several ideal gas law concepts. We conducted a 2 × 3 factorial design experiment. We compared two scaffolding conditions: (1) the inter- level scaffolding condition in which participants received inter-level questions and experienced the dynamic link function in the simulation-based environment and (2) the intra- level scaffolding condition in which participants received intra-level questions and did not experience the dynamic link function. We also compared three different sequences of representational activities: macro-symbolic-micro, micro-symbolic-macro and symbolic-micro-macro. For the scaffolding variable, we found that the inter- level scaffolding condition produced significantly better performance in both knowledge comprehension and application, compared to the intra- level scaffolding condition. For the sequence variable, we found that the macro-symbolic-micro sequence produced significantly better knowledge comprehension performance than the other two sequences; however, it did not benefit knowledge application performance. There was a trend that the treatment group who experienced inter- level scaffolding and the micro-symbolic-macro sequence achieved the best knowledge application performance.

Understanding differences in electronic health record (EHR) use: linking individual physicians' perceptions of uncertainty and EHR use patterns in ambulatory care.

PubMed

Lanham, Holly Jordan; Sittig, Dean F; Leykum, Luci K; Parchman, Michael L; Pugh, Jacqueline A; McDaniel, Reuben R

2014-01-01

Electronic health records (EHR) hold great promise for managing patient information in ways that improve healthcare delivery. Physicians differ, however, in their use of this health information technology (IT), and these differences are not well understood. The authors study the differences in individual physicians' EHR use patterns and identify perceptions of uncertainty as an important new variable in understanding EHR use. Qualitative study using semi-structured interviews and direct observation of physicians (n=28) working in a multispecialty outpatient care organization. We identified physicians' perceptions of uncertainty as an important variable in understanding differences in EHR use patterns. Drawing on theories from the medical and organizational literatures, we identified three categories of perceptions of uncertainty: reduction, absorption, and hybrid. We used an existing model of EHR use to categorize physician EHR use patterns as high, medium, and low based on degree of feature use, level of EHR-enabled communication, and frequency that EHR use patterns change. Physicians' perceptions of uncertainty were distinctly associated with their EHR use patterns. Uncertainty reductionists tended to exhibit high levels of EHR use, uncertainty absorbers tended to exhibit low levels of EHR use, and physicians demonstrating both perspectives of uncertainty (hybrids) tended to exhibit medium levels of EHR use. We find evidence linking physicians' perceptions of uncertainty with EHR use patterns. Study findings have implications for health IT research, practice, and policy, particularly in terms of impacting health IT design and implementation efforts in ways that consider differences in physicians' perceptions of uncertainty.

Phenotypic characterization of X-linked retinoschisis: Clinical, electroretinography, and optical coherence tomography variables

PubMed Central

Neriyanuri, Srividya; Dhandayuthapani, Sudha; Arunachalam, Jayamuruga Pandian; Raman, Rajiv

2016-01-01

Aims: To study the phenotypic characteristics of X-linked retinoschisis (XLRS) and report the clinical, electroretinogram (ERG), and optical coherence tomography (OCT) variables in Indian eyes. Design: A retrospective study. Materials and Methods: Medical records of 21 patients with retinoschisis who were genetically confirmed to have RS1 mutation were reviewed. The phenotype characterization included the age of onset, best-corrected visual acuity, refractive error, fundus findings, OCT, and ERG. Statistical Analysis Used: Data from both the eyes were used for analysis. A P < 0.05 was set as statistical significance. Data were not normally distributed (P < 0.05, Shapiro wilk); hence, nonparametric tests were used for statistical analysis. Results: All were males whose mean age of presentation was 9 years. Visual acuity was moderately impaired (median 0.6 logMAR, interquartile range: 0.47, 1) in these eyes with a hyperopic refractive error of median +1.75 Ds (interquartile range: +0.50 Ds, +4.25 Ds). About 54.7% of the eyes had both foveal and peripheral schisis, isolated foveal schisis was seen in 28.5% of the eyes, and schisis with retinal detachment was seen in 16.6% of the eyes. The inner nuclear layer was found to be commonly involved in the schisis, followed by outer nuclear and plexiform layers as evident on OCT. On ERG, a- and b-wave amplitudes were significantly reduced in eyes with foveal and peripheral schisis when compared to the eyes with only foveal schisis (P < 0.05). Conclusions: XLRS has phenotypic heterogeneity as evident on OCT, ERG, and clinical findings. PMID:27609164

Assessing the climate-scale variability of atmospheric rivers affecting western North America

NASA Astrophysics Data System (ADS)

Gershunov, Alexander; Shulgina, Tamara; Ralph, F. Martin; Lavers, David A.; Rutz, Jonathan J.

2017-08-01

A new method for automatic detection of atmospheric rivers (ARs) is developed and applied to an atmospheric reanalysis, yielding an extensive catalog of ARs land-falling along the west coast of North America during 1948-2017. This catalog provides a large array of variables that can be used to examine AR cases and their climate-scale variability in exceptional detail. The new record of AR activity, as presented, validated and examined here, provides a perspective on the seasonal cycle and the interannual-interdecadal variability of AR activity affecting the hydroclimate of western North America. Importantly, AR intensity does not exactly follow the climatological pattern of AR frequency. Strong links to hydroclimate are demonstrated using a high-resolution precipitation data set. We describe the seasonal progression of AR activity and diagnose linkages with climate variability expressed in Pacific sea surface temperatures, revealing links to Pacific decadal variability, recent regional anomalies, as well as a generally rising trend in land-falling AR activity. The latter trend is consistent with a long-term increase in vapor transport from the warming North Pacific onto the North American continent. The new catalog provides unprecedented opportunities to study the climate-scale behavior and predictability of ARs affecting western North America.

Channel CAT: A Tactical Link Analysis Tool

DTIC Science & Technology

1997-09-01

NAVAL POSTGRADUATE SCHOOL Monterey, California THESIS CHANNEL CAT : A TACTICAL LINK ANALYSIS TOOL by Michael Glenn Coleman September 1997 Thesis...REPORT TYPE AND DATES COVERED September 1997 Master’s Thesis 4. TITLE AND SUBTITLE CHANNEL CAT : A TACTICAL LINK ANALYSIS TOOL 5. FUNDING NUMBERS 6...tool, the Channel Capacity Analysis Tool (Channel CAT ), designed to provide an automated tool for the anlysis of design decisions in developing client

Linking Composite Scores: Effects of Anchor Test Length and Content Representativeness. Research Report. ETS RR-16-36

ERIC Educational Resources Information Center

Lin, Peng; Dorans, Neil; Weeks, Jonathan

2016-01-01

The nonequivalent groups with anchor test (NEAT) design is frequently used in test score equating or linking. One important assumption of the NEAT design is that the anchor test is a miniversion of the 2 tests to be equated/linked. When the content of the 2 tests is different, it is not possible for the anchor test to be adequately representative…

Linking crop yield anomalies to large-scale atmospheric circulation in Europe.

PubMed

Ceglar, Andrej; Turco, Marco; Toreti, Andrea; Doblas-Reyes, Francisco J

2017-06-15

Understanding the effects of climate variability and extremes on crop growth and development represents a necessary step to assess the resilience of agricultural systems to changing climate conditions. This study investigates the links between the large-scale atmospheric circulation and crop yields in Europe, providing the basis to develop seasonal crop yield forecasting and thus enabling a more effective and dynamic adaptation to climate variability and change. Four dominant modes of large-scale atmospheric variability have been used: North Atlantic Oscillation, Eastern Atlantic, Scandinavian and Eastern Atlantic-Western Russia patterns. Large-scale atmospheric circulation explains on average 43% of inter-annual winter wheat yield variability, ranging between 20% and 70% across countries. As for grain maize, the average explained variability is 38%, ranging between 20% and 58%. Spatially, the skill of the developed statistical models strongly depends on the large-scale atmospheric variability impact on weather at the regional level, especially during the most sensitive growth stages of flowering and grain filling. Our results also suggest that preceding atmospheric conditions might provide an important source of predictability especially for maize yields in south-eastern Europe. Since the seasonal predictability of large-scale atmospheric patterns is generally higher than the one of surface weather variables (e.g. precipitation) in Europe, seasonal crop yield prediction could benefit from the integration of derived statistical models exploiting the dynamical seasonal forecast of large-scale atmospheric circulation.

Choice of surrogate tissue influences neonatal EWAS findings.

PubMed

Lin, Xinyi; Teh, Ai Ling; Chen, Li; Lim, Ives Yubin; Tan, Pei Fang; MacIsaac, Julia L; Morin, Alexander M; Yap, Fabian; Tan, Kok Hian; Saw, Seang Mei; Lee, Yung Seng; Holbrook, Joanna D; Godfrey, Keith M; Meaney, Michael J; Kobor, Michael S; Chong, Yap Seng; Gluckman, Peter D; Karnani, Neerja

2017-12-05

Epigenomes are tissue specific and thus the choice of surrogate tissue can play a critical role in interpreting neonatal epigenome-wide association studies (EWAS) and in their extrapolation to target tissue. To develop a better understanding of the link between tissue specificity and neonatal EWAS, and the contributions of genotype and prenatal factors, we compared genome-wide DNA methylation of cord tissue and cord blood, two of the most accessible surrogate tissues at birth. In 295 neonates, DNA methylation was profiled using Infinium HumanMethylation450 beadchip arrays. Sites of inter-individual variability in DNA methylation were mapped and compared across the two surrogate tissues at birth, i.e., cord tissue and cord blood. To ascertain the similarity to target tissues, DNA methylation profiles of surrogate tissues were compared to 25 primary tissues/cell types mapped under the Epigenome Roadmap project. Tissue-specific influences of genotype on the variable CpGs were also analyzed. Finally, to interrogate the impact of the in utero environment, EWAS on 45 prenatal factors were performed and compared across the surrogate tissues. Neonatal EWAS results were tissue specific. In comparison to cord blood, cord tissue showed higher inter-individual variability in the epigenome, with a lower proportion of CpGs influenced by genotype. Both neonatal tissues were good surrogates for target tissues of mesodermal origin. They also showed distinct phenotypic associations, with effect sizes of the overlapping CpGs being in the same order of magnitude. The inter-relationship between genetics, prenatal factors and epigenetics is tissue specific, and requires careful consideration in designing and interpreting future neonatal EWAS. This birth cohort is a prospective observational study, designed to study the developmental origins of health and disease, and was retrospectively registered on 1 July 2010 under the identifier NCT01174875 .

Effects of biotic and abiotic indices on long term soil moisture data in a grassland biodiversity experiment

NASA Astrophysics Data System (ADS)

Fischer, Christine; Hohenbrink, Tobias; Leimer, Sophia; Roscher, Christiane; Ravenek, Janneke; de Kroon, Hans; Kreutziger, Yvonne; Wirth, Christian; Eisenhauer, Nico; Gleixner, Gerd; Weigelt, Alexandra; Mommer, Liesje; Beßler, Holger; Schröder, Boris; Hildebrandt, Anke

2015-04-01

Soil moisture is the dynamic link between climate, soil and vegetation and the dynamics and variation are affected by several often interrelated factors such as soil texture, soil structural parameters (soil organic carbon) and vegetation parameters (belowground- and aboveground biomass). For the characterization and estimation of soil moisture and its variability and the resulting water fluxes and solute transports, the knowledge of the relative importance of these factors is of major challenge for hydrology and bioclimatology. Because of the heterogeneity of these factors, soil moisture varies strongly over time and space. Our objective was to assess the spatio-temporal variability of soil moisture and factors which could explain that variability, like soil properties and vegetation cover, in in a long term biodiversity experiment (Jena Experiment). The Jena Experiment consist 86 plots on which plant species richness (0, 1, 2, 4, 8, 16, and 60) and functional groups (legumes, grasses, tall herbs, and small herbs) were manipulated in a factorial design Soil moisture measurements were performed weekly April to September 2003-2005 and 2008-2013 using Delta T theta probe. Measurements were integrated to three depth intervals: 0.0 - 0.20, 0.20 - 0.40 and 0.40 - 0.70 m. We analyze the spatio-temporal patterns of soil water content on (i) the normalized time series and (ii) the first components obtained from a principal component analysis (PCA). Both were correlated with the design variables of the Jena Experiment (plant species richness and plant functional groups) and other influencing factors such as soil texture, soil structural variables and vegetation parameters. For the time stability of soil water content, the analysis showed that plots containing grasses was consistently drier than average at the soil surface in all observed years while plots containing legumes comparatively moister, but only up to the year 2008. In 0.40 - 0.70 m soil deep plots presence of small herbs led to higher than average soil moisture in some years (2008, 2012, 2013). Interestingly, plant species richness led to moister than average subsoil at the beginning of the experiment (2003 and 2004), which changed to lower than average up to the year 2010 in all depths. There was no effect of species diversity in the years since 2010, although species diversity generally increases leaf area index and aboveground biomass. The first component from the PCA analysis described the mean behavior in time of all soil moisture time series. The second component reflected the impact of soil depth. The first two components explained 76% of the data set total variance. The third component is linked to plant species richness and explained about 4 % of the total variance of soil moisture data. The fourth component, which explained 2.4 %, showed a high correlation to soil texture. Within this study we investigate the dominant factors controlling spatio-temporal patterns of soil moisture at several soil depths. Although climate and soil depths were the most important drivers, other factors like plant species richness and soil texture affected the temporal variation while certain plant functional groups were important for the spatial variability.

Multidisciplinary optimization of a controlled space structure using 150 design variables

NASA Technical Reports Server (NTRS)

James, Benjamin B.

1993-01-01

A controls-structures interaction design method is presented. The method coordinates standard finite-element structural analysis, multivariable controls, and nonlinear programming codes and allows simultaneous optimization of the structure and control system of a spacecraft. Global sensitivity equations are used to account for coupling between the disciplines. Use of global sensitivity equations helps solve optimization problems that have a large number of design variables and a high degree of coupling between disciplines. The preliminary design of a generic geostationary platform is used to demonstrate the multidisciplinary optimization method. Design problems using 15, 63, and 150 design variables to optimize truss member sizes and feedback gain values are solved and the results are presented. The goal is to reduce the total mass of the structure and the vibration control system while satisfying constraints on vibration decay rate. Incorporation of the nonnegligible mass of actuators causes an essential coupling between structural design variables and control design variables.

Design of mechanical arm for an automatic sorting system of recyclable cans

NASA Astrophysics Data System (ADS)

Resti, Y.; Mohruni, A. S.; Burlian, F.; Yani, I.; Amran, A.

2018-04-01

The use of a mechanical arm for an automatic sorting system of used cans should be designed carefully. The right design will result in a high precision sorting rate and a short sorting time. The design includes first; design manipulator,second; determine link and joint specifications, and third; build mechanical systems and control systems. This study aims to design the mechanical arm as a hardware system for automatic cans sorting system. The material used for the manipulator is the aluminum plate. The manipulator is designed using 6 links and 6 join where the 6th link is the end effectorand the 6th join is the gripper. As a driving motor used servo motor, while as a microcontroller used Arduino Uno which is connected with Matlab programming language. Based on testing, a mechanical arm designed for this recyclable canned recycling system has a precision sorting rate at 93%, where the average total time required for sorting is 10.82 seconds.

Connecting Atlantic temperature variability and biological cycling in two earth system models

NASA Astrophysics Data System (ADS)

Gnanadesikan, Anand; Dunne, John P.; Msadek, Rym

2014-05-01

Connections between the interdecadal variability in North Atlantic temperatures and biological cycling have been widely hypothesized. However, it is unclear whether such connections are due to small changes in basin-averaged temperatures indicated by the Atlantic Multidecadal Oscillation (AMO) Index, or whether both biological cycling and the AMO index are causally linked to changes in the Atlantic Meridional Overturning Circulation (AMOC). We examine interdecadal variability in the annual and month-by-month diatom biomass in two Earth System Models with the same formulations of atmospheric, land, sea ice and ocean biogeochemical dynamics but different formulations of ocean physics and thus different AMOC structures and variability. In the isopycnal-layered ESM2G, strong interdecadal changes in surface salinity associated with changes in AMOC produce spatially heterogeneous variability in convection, nutrient supply and thus diatom biomass. These changes also produce changes in ice cover, shortwave absorption and temperature and hence the AMO Index. Off West Greenland, these changes are consistent with observed changes in fisheries and support climate as a causal driver. In the level-coordinate ESM2M, nutrient supply is much higher and interdecadal changes in diatom biomass are much smaller in amplitude and not strongly linked to the AMO index.

Cross-Linked Nanotube Materials with Variable Stiffness Tethers

NASA Technical Reports Server (NTRS)

Frankland, Sarah-Jane V.; Odegard, Gregory M.; Herzog, Matthew N.; Gates, Thomas S.; Fay, Catherine C.

2004-01-01

The constitutive properties of a cross-linked single-walled carbon nanotube material are predicted with a multi-scale model. The material is modeled as a transversely isotropic solid using concepts from equivalent-continuum modeling. The elastic constants are determined using molecular dynamics simulation. Some parameters of the molecular force field are determined specifically for the cross-linker from ab initio calculations. A demonstration of how the cross-linked nanotubes may affect the properties of a nanotube/polyimide composite is included using a micromechanical analysis.

Design approaches to experimental mediation☆

PubMed Central

Pirlott, Angela G.; MacKinnon, David P.

2016-01-01

Identifying causal mechanisms has become a cornerstone of experimental social psychology, and editors in top social psychology journals champion the use of mediation methods, particularly innovative ones when possible (e.g. Halberstadt, 2010, Smith, 2012). Commonly, studies in experimental social psychology randomly assign participants to levels of the independent variable and measure the mediating and dependent variables, and the mediator is assumed to causally affect the dependent variable. However, participants are not randomly assigned to levels of the mediating variable(s), i.e., the relationship between the mediating and dependent variables is correlational. Although researchers likely know that correlational studies pose a risk of confounding, this problem seems forgotten when thinking about experimental designs randomly assigning participants to levels of the independent variable and measuring the mediator (i.e., “measurement-of-mediation” designs). Experimentally manipulating the mediator provides an approach to solving these problems, yet these methods contain their own set of challenges (e.g., Bullock, Green, & Ha, 2010). We describe types of experimental manipulations targeting the mediator (manipulations demonstrating a causal effect of the mediator on the dependent variable and manipulations targeting the strength of the causal effect of the mediator) and types of experimental designs (double randomization, concurrent double randomization, and parallel), provide published examples of the designs, and discuss the strengths and challenges of each design. Therefore, the goals of this paper include providing a practical guide to manipulation-of-mediator designs in light of their challenges and encouraging researchers to use more rigorous approaches to mediation because manipulation-of-mediator designs strengthen the ability to infer causality of the mediating variable on the dependent variable. PMID:27570259

Design approaches to experimental mediation.

PubMed

Pirlott, Angela G; MacKinnon, David P

2016-09-01

Identifying causal mechanisms has become a cornerstone of experimental social psychology, and editors in top social psychology journals champion the use of mediation methods, particularly innovative ones when possible (e.g. Halberstadt, 2010, Smith, 2012). Commonly, studies in experimental social psychology randomly assign participants to levels of the independent variable and measure the mediating and dependent variables, and the mediator is assumed to causally affect the dependent variable. However, participants are not randomly assigned to levels of the mediating variable(s), i.e., the relationship between the mediating and dependent variables is correlational. Although researchers likely know that correlational studies pose a risk of confounding, this problem seems forgotten when thinking about experimental designs randomly assigning participants to levels of the independent variable and measuring the mediator (i.e., "measurement-of-mediation" designs). Experimentally manipulating the mediator provides an approach to solving these problems, yet these methods contain their own set of challenges (e.g., Bullock, Green, & Ha, 2010). We describe types of experimental manipulations targeting the mediator (manipulations demonstrating a causal effect of the mediator on the dependent variable and manipulations targeting the strength of the causal effect of the mediator) and types of experimental designs (double randomization, concurrent double randomization, and parallel), provide published examples of the designs, and discuss the strengths and challenges of each design. Therefore, the goals of this paper include providing a practical guide to manipulation-of-mediator designs in light of their challenges and encouraging researchers to use more rigorous approaches to mediation because manipulation-of-mediator designs strengthen the ability to infer causality of the mediating variable on the dependent variable.

School burnout: increased sympathetic vasomotor tone and attenuated ambulatory diurnal blood pressure variability in young adult women.

PubMed

May, Ross W; Sanchez-Gonzalez, Marcos A; Fincham, Frank D

2015-01-01

Two studies examined autonomic and cardiovascular functioning that may link school burnout to cardiovascular risk factors in young healthy adult females. Study 1 (N = 136) investigated whether school burnout was related to resting values of blood pressure (BP) and blood pressure variability (BPV) through laboratory beat-to-beat BP assessment. Study 2 (N = 94) examined the link between school burnout and diurnal BPV through ambulatory BP monitoring. Controlling for anxiety and depressive symptomatology, school burnout demonstrated strong positive relationships with indices of cardiac sympathovagal tone, sympathetic vasomotor tone, inefficient myocardial oxygen consumption, increased 24-h ambulatory heart rate and BP, blunted BP diurnal variability, and increased arterial stiffness. These studies establish cardiovascular biomarkers of school burnout and suggest that even in a seemingly healthy sample school burnout may predispose females to increased cardiovascular risk. Several future lines of research are outlined.

Generational differences of the frontline nursing workforce in relation to job satisfaction: what does the literature reveal?

PubMed

Saber, Deborah A

2013-01-01

The job satisfaction of registered nurses has been found to be associated with retention, organizational commitment, workforce safety, and cost savings to health care organizations. Satisfaction of the workforce is vital because nursing turnover can be detrimental for a labor force that is growing older. However, the summation of the most important variables that are linked to job satisfaction has been difficult to discern in part because the workforce includes 3 main generations (ie, Baby Boomers, Gen Xers, and Millennials) with unique work values that drive their job satisfiers. This article provides a review of existing literature to examine the differences in variables that are linked to job satisfaction that exist between the generational cohorts. Differences in stress sources, need for work-life balance, and compensation are discussed. The knowledge about generationally driven variables that influence job satisfaction can help managers develop strategies to maintain a diverse nursing workforce.

Four novel connexin 32 mutations in X-linked Charcot-Marie-Tooth disease. Phenotypic variability and central nervous system involvement.

PubMed

Karadima, Georgia; Koutsis, Georgios; Raftopoulou, Maria; Floroskufi, Paraskewi; Karletidi, Karolina-Maria; Panas, Marios

2014-06-15

Charcot-Marie-Tooth (CMT) disease, the most common hereditary neuropathy, is clinically and genetically heterogeneous. X-linked CMT (CMTX) is usually caused by mutations in the gap junction protein b 1 gene (GJB1) coding for connexin 32 (Cx32). The clinical manifestations of CMTX are characterized by significant variability, with some patients exhibiting central nervous system (CNS) involvement. We report four novel mutations in GJB1, c.191G>A (p.Cys64Tyr), c.508G>T (p.Val170Phe), c.778A>G (p.Lys260Glu) and c.300C>G (p.His100Gln) identified in four unrelated Greek families. These mutations were characterized by variable phenotypic expression, including a family with the Roussy-Lévy syndrome, and three of them were associated with mild clinical CNS manifestations. Copyright © 2014. Published by Elsevier B.V.

Disruptions of El Niño–Southern Oscillation teleconnections by the Madden–Julian Oscillation

USGS Publications Warehouse

Hoell, Andrew; Barlow, Mathew; Wheeler, Mathew; Funk, Christopher C.

2014-01-01

The El Niño–Southern Oscillation (ENSO) is the leading mode of interannual variability, with global impacts on weather and climate that have seasonal predictability. Research on the link between interannual ENSO variability and the leading mode of intraseasonal variability, the Madden–Julian oscillation (MJO), has focused mainly on the role of MJO initiating or terminating ENSO. We use observational analysis and modeling to show that the MJO has an important simultaneous link to ENSO: strong MJO activity significantly weakens the atmospheric branch of ENSO. For weak MJO conditions relative to strong MJO conditions, the average magnitude of ENSO-associated tropical precipitation anomalies increases by 63%, and the strength of hemispheric teleconnections increases by 58%. Since the MJO has predictability beyond three weeks, the relationships shown here suggest that there may be subseasonal predictability of the ENSO teleconnections to continental circulation and precipitation.

Resolving the Conflict Between Associative Overdominance and Background Selection

PubMed Central

Zhao, Lei; Charlesworth, Brian

2016-01-01

In small populations, genetic linkage between a polymorphic neutral locus and loci subject to selection, either against partially recessive mutations or in favor of heterozygotes, may result in an apparent selective advantage to heterozygotes at the neutral locus (associative overdominance) and a retardation of the rate of loss of variability by genetic drift at this locus. In large populations, selection against deleterious mutations has previously been shown to reduce variability at linked neutral loci (background selection). We describe analytical, numerical, and simulation studies that shed light on the conditions under which retardation vs. acceleration of loss of variability occurs at a neutral locus linked to a locus under selection. We consider a finite, randomly mating population initiated from an infinite population in equilibrium at a locus under selection. With mutation and selection, retardation occurs only when S, the product of twice the effective population size and the selection coefficient, is of order 1. With S >> 1, background selection always causes an acceleration of loss of variability. Apparent heterozygote advantage at the neutral locus is, however, always observed when mutations are partially recessive, even if there is an accelerated rate of loss of variability. With heterozygote advantage at the selected locus, loss of variability is nearly always retarded. The results shed light on experiments on the loss of variability at marker loci in laboratory populations and on the results of computer simulations of the effects of multiple selected loci on neutral variability. PMID:27182952

Modeling variability in air pollution-related health damages from individual airport emissions.

PubMed

Penn, Stefani L; Boone, Scott T; Harvey, Brian C; Heiger-Bernays, Wendy; Tripodis, Yorghos; Arunachalam, Sarav; Levy, Jonathan I

2017-07-01

In this study, we modeled concentrations of fine particulate matter (PM 2.5 ) and ozone (O 3 ) attributable to precursor emissions from individual airports in the United States, developing airport-specific health damage functions (deaths per 1000t of precursor emissions) and physically-interpretable regression models to explain variability in these functions. We applied the Community Multiscale Air Quality model using the Decoupled Direct Method to isolate PM 2.5 - or O 3 -related contributions from precursor pollutants emitted by 66 individual airports. We linked airport- and pollutant-specific concentrations with population data and literature-based concentration-response functions to create health damage functions. Deaths per 1000t of primary PM 2.5 emissions ranged from 3 to 160 across airports, with variability explained by population patterns within 500km of the airport. Deaths per 1000t of precursors for secondary PM 2.5 varied across airports from 0.1 to 2.7 for NOx, 0.06 to 2.9 for SO 2 , and 0.06 to 11 for VOCs, with variability explained by population patterns and ambient concentrations influencing particle formation. Deaths per 1000t of O 3 precursors ranged from -0.004 to 1.0 for NOx and 0.03 to 1.5 for VOCs, with strong seasonality and influence of ambient concentrations. Our findings reinforce the importance of location- and source-specific health damage functions in design of health-maximizing emissions control policies. Copyright © 2017 Elsevier Inc. All rights reserved.

What predictors matter: Risk factors for late adolescent outcomes.

PubMed

Wall-Wieler, Elizabeth; Roos, Leslie L; Chateau, Dan G; Rosella, Laura C

2016-06-27

A life course approach and linked Manitoba data from birth to age 18 were used to facilitate comparisons of two important outcomes: high school graduation and Attention-Deficit/Hyperactivity Disorder (ADHD). With a common set of variables, we sought to answer the following questions: Do the measures predicting high school graduation differ from those that predict ADHD? Which factors are most important? How well do the models fit each outcome? Administrative data from the Population Health Research Data Repository at the Manitoba Centre for Health Policy were used to conduct one of the strongest observational designs: multilevel modelling of large population (n = 62,739) and sibling (n = 29,444) samples. Variables included are neighbourhood characteristics, measures of family stability, and mental and physical health conditions in childhood and adolescence. The adverse childhood experiences important for each outcome differ. While family instability and economic adversity more strongly affect failing to graduate from high school, adverse health events in childhood and early adolescence have a greater effect on late adolescent ADHD. The variables included in the model provided excellent accuracy and discrimination. These results offer insights on the role of several family and social variables and can serve as the basis for reliable, valid prediction tools that can identify high-risk individuals. Applying such a tool at the population level would provide insight into the future burden of these outcomes in an entire region or nation and further quantify the burden of risk in the population.

End-point controller design for an experimental two-link flexible manipulator using convex optimization

NASA Technical Reports Server (NTRS)

Oakley, Celia M.; Barratt, Craig H.

1990-01-01

Recent results in linear controller design are used to design an end-point controller for an experimental two-link flexible manipulator. A nominal 14-state linear-quadratic-Gaussian (LQG) controller was augmented with a 528-tap finite-impulse-response (FIR) filter designed using convex optimization techniques. The resulting 278-state controller produced improved end-point trajectory tracking and disturbance rejection in simulation and experimentally in real time.

Structural differences between glycosylated, disulfide-linked heterodimeric Knob-into-Hole Fc fragment and its homodimeric Knob-Knob and Hole-Hole side products.

PubMed

Kuglstatter, A; Stihle, M; Neumann, C; Müller, C; Schaefer, W; Klein, C; Benz, J

2017-09-01

An increasing number of bispecific therapeutic antibodies are progressing through clinical development. The Knob-into-Hole (KiH) technology uses complementary mutations in the CH3 region of the antibody Fc fragment to achieve heavy chain heterodimerization. Here we describe the X-ray crystal structures of glycosylated and disulfide-engineered heterodimeric KiH Fc fragment and its homodimeric Knob-Knob and Hole-Hole side products. The heterodimer structure confirms the KiH design principle and supports the hypothesis that glycosylation stabilizes a closed Fc conformation. Both homodimer structures show parallel Fc fragment architectures, in contrast to recently reported crystal structures of the corresponding aglycosylated Fc fragments which in the absence of disulfide mutations show an unexpected antiparallel arrangement. The glycosylated Knob-Knob Fc fragment is destabilized as indicated by variability in the relative orientation of its CH3 domains. The glycosylated Hole-Hole Fc fragment shows an unexpected intermolecular disulfide bond via the introduced Y349C Hole mutation which results in a large CH3 domain shift and a new CH3-CH3 interface. The crystal structures of glycosylated, disulfide-linked KiH Fc fragment and its Knob-Knob and Hole-Hole side products reported here will facilitate further design of highly efficient antibody heterodimerization strategies. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

(Finite) statistical size effects on compressive strength.

PubMed

Weiss, Jérôme; Girard, Lucas; Gimbert, Florent; Amitrano, David; Vandembroucq, Damien

2014-04-29

The larger structures are, the lower their mechanical strength. Already discussed by Leonardo da Vinci and Edmé Mariotte several centuries ago, size effects on strength remain of crucial importance in modern engineering for the elaboration of safety regulations in structural design or the extrapolation of laboratory results to geophysical field scales. Under tensile loading, statistical size effects are traditionally modeled with a weakest-link approach. One of its prominent results is a prediction of vanishing strength at large scales that can be quantified in the framework of extreme value statistics. Despite a frequent use outside its range of validity, this approach remains the dominant tool in the field of statistical size effects. Here we focus on compressive failure, which concerns a wide range of geophysical and geotechnical situations. We show on historical and recent experimental data that weakest-link predictions are not obeyed. In particular, the mechanical strength saturates at a nonzero value toward large scales. Accounting explicitly for the elastic interactions between defects during the damage process, we build a formal analogy of compressive failure with the depinning transition of an elastic manifold. This critical transition interpretation naturally entails finite-size scaling laws for the mean strength and its associated variability. Theoretical predictions are in remarkable agreement with measurements reported for various materials such as rocks, ice, coal, or concrete. This formalism, which can also be extended to the flowing instability of granular media under multiaxial compression, has important practical consequences for future design rules.

Colloidal Covalent Organic Frameworks

PubMed Central

2017-01-01

Covalent organic frameworks (COFs) are two- or three-dimensional (2D or 3D) polymer networks with designed topology and chemical functionality, permanent porosity, and high surface areas. These features are potentially useful for a broad range of applications, including catalysis, optoelectronics, and energy storage devices. But current COF syntheses offer poor control over the material’s morphology and final form, generally providing insoluble and unprocessable microcrystalline powder aggregates. COF polymerizations are often performed under conditions in which the monomers are only partially soluble in the reaction solvent, and this heterogeneity has hindered understanding of their polymerization or crystallization processes. Here we report homogeneous polymerization conditions for boronate ester-linked, 2D COFs that inhibit crystallite precipitation, resulting in stable colloidal suspensions of 2D COF nanoparticles. The hexagonal, layered structures of the colloids are confirmed by small-angle and wide-angle X-ray scattering, and kinetic characterization provides insight into the growth process. The colloid size is modulated by solvent conditions, and the technique is demonstrated for four 2D boronate ester-linked COFs. The diameter of individual COF nanoparticles in solution is monitored and quantified during COF growth and stabilization at elevated temperature using in situ variable-temperature liquid cell transmission electron microscopy imaging, a new characterization technique that complements conventional bulk scattering techniques. Solution casting of the colloids yields a free-standing transparent COF film with retained crystallinity and porosity, as well as preferential crystallite orientation. Collectively this structural control provides new opportunities for understanding COF formation and designing morphologies for device applications. PMID:28149954

Preliminary Results from the AFRL-NASA W/V-Band Terrestrial Link Experiment in Albuquerque, NM

NASA Technical Reports Server (NTRS)

Zemba, Michael; Nessel, James; Houts, Jacquelynne; Tarasenko, Nicholas; Lane, Steven; Murrell, David

2016-01-01

Atmospheric propagation models and the measurements that train them are critical to the design of efficient and effective space-ground links. As communication systems advance to higher frequencies in search of higher data rates and open spectrum, a lack of data at these frequencies necessitates new measurements to properly develop, validate, and refine the models used for link budgeting and system design. In collaboration with the Air Force Research Laboratory (AFRL), NASA Glenn Research Center has deployed the WV-band Terrestrial Link Experiment (WTLE) in Albuquerque, NM to conduct a measurement campaign at 72 and 84 GHz, among the first atmospheric propagation measurements at these frequencies. WTLE has been operational since October 1, 2015, and the system design shall be herein discussed alongside preliminary results and performance.

Modulation and modeling of monoclonal antibody N-linked glycosylation in mammalian cell perfusion reactors.

PubMed

Karst, Daniel J; Scibona, Ernesto; Serra, Elisa; Bielser, Jean-Marc; Souquet, Jonathan; Stettler, Matthieu; Broly, Hervé; Soos, Miroslav; Morbidelli, Massimo; Villiger, Thomas K

2017-09-01

Mammalian cell perfusion cultures are gaining renewed interest as an alternative to traditional fed-batch processes for the production of therapeutic proteins, such as monoclonal antibodies (mAb). The steady state operation at high viable cell density allows the continuous delivery of antibody product with increased space-time yield and reduced in-process variability of critical product quality attributes (CQA). In particular, the production of a confined mAb N-linked glycosylation pattern has the potential to increase therapeutic efficacy and bioactivity. In this study, we show that accurate control of flow rates, media composition and cell density of a Chinese hamster ovary (CHO) cell perfusion bioreactor allowed the production of a constant glycosylation profile for over 20 days. Steady state was reached after an initial transition phase of 6 days required for the stabilization of extra- and intracellular processes. The possibility to modulate the glycosylation profile was further investigated in a Design of Experiment (DoE), at different viable cell density and media supplement concentrations. This strategy was implemented in a sequential screening approach, where various steady states were achieved sequentially during one culture. It was found that, whereas high ammonia levels reached at high viable cell densities (VCD) values inhibited the processing to complex glycan structures, the supplementation of either galactose, or manganese as well as their synergy significantly increased the proportion of complex forms. The obtained experimental data set was used to compare the reliability of a statistical response surface model (RSM) to a mechanistic model of N-linked glycosylation. The latter outperformed the response surface predictions with respect to its capability and reliability in predicting the system behavior (i.e., glycosylation pattern) outside the experimental space covered by the DoE design used for the model parameter estimation. Therefore, we can conclude that the modulation of glycosylation in a sequential steady state approach in combination with mechanistic model represents an efficient and rational strategy to develop continuous processes with desired N-linked glycosylation patterns. Biotechnol. Bioeng. 2017;114: 1978-1990. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Building Trust and Feeling Well: Examining Intraindividual and Interpersonal Outcomes and Underlying Mechanisms of Listening

ERIC Educational Resources Information Center

Lloyd, Karina J.; Boer, Diana; Kluger, Avraham N.; Voelpel, Sven C.

2015-01-01

We investigated perceived listening quality in relation to individual (self-clarity and emotional well-being) and dyadic variables (social attraction and trust). Specifically, we proposed that the link between perceived listening quality and emotional well-being is mediated by self-clarity, and that the link between perceived listening and trust…

Disruptive Promise: The Links Intervention and Its Impact on Multiple, Multimodal, Internet Text Integration

ERIC Educational Resources Information Center

Schira Hagerman, Michelle

2014-01-01

This dissertation study presents an instructional intervention called LINKS: Learning to Integrate InterNet Knowledge Strategically. It reports evidence of the intervention's impact on two variables: (a) ninth graders' use of ten online reading and integration strategies while engaged in dyadic online inquiry on science topics in school, and (b)…

DARPA Antibody Technology Program Standardized Test Bed for Antibody Characterization: Characterization of an MS2 ScFv Antibody

DTIC Science & Technology

2016-03-01

performance in an enzyme-linked immunosorbent assay ( ELISA ), with little regard for quantification of the full spectrum of variables affecting antibody...Program (ATP) Quality MS2 coat protein (MS2CP) Enzyme-linked immunosorbent assay ( ELISA ) 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT...5 2.7 ELISA ................................................................................................................5

Adaptive output feedback control of flexible-joint robots using neural networks: dynamic surface design approach.

PubMed

Yoo, Sung Jin; Park, Jin Bae; Choi, Yoon Ho

2008-10-01

In this paper, we propose a new robust output feedback control approach for flexible-joint electrically driven (FJED) robots via the observer dynamic surface design technique. The proposed method only requires position measurements of the FJED robots. To estimate the link and actuator velocity information of the FJED robots with model uncertainties, we develop an adaptive observer using self-recurrent wavelet neural networks (SRWNNs). The SRWNNs are used to approximate model uncertainties in both robot (link) dynamics and actuator dynamics, and all their weights are trained online. Based on the designed observer, the link position tracking controller using the estimated states is induced from the dynamic surface design procedure. Therefore, the proposed controller can be designed more simply than the observer backstepping controller. From the Lyapunov stability analysis, it is shown that all signals in a closed-loop adaptive system are uniformly ultimately bounded. Finally, the simulation results on a three-link FJED robot are presented to validate the good position tracking performance and robustness of the proposed control system against payload uncertainties and external disturbances.

Anatomy of an experimental two-link flexible manipulator under end-point control

NASA Technical Reports Server (NTRS)

Oakley, Celia M.; Cannon, Robert H., Jr.

1990-01-01

The design and experimental implementation of an end-point controller for two-link flexible manipulators are presented. The end-point controller is based on linear quadratic Gaussian (LQG) theory and is shown to exhibit significant improvements in trajectory tracking over a conventional controller design. To understand the behavior of the manipulator structure under end-point control, a strobe sequence illustrating the link deflections during a typical slew maneuver is included.

Low-cost housing design and provision: A case study of Kenya

NASA Astrophysics Data System (ADS)

Kabo, Felichism W.

Shelter is as basic a human need as food and water. Today, many people in Third World countries live in sub-standard housing, or lack shelter altogether. Prior research addresses either one of two housing dimensions: broader provision processes, or specific aspects of design. This dissertation is an effort at addressing both dimensions, the underlying premise being that their inter-connectedness demands an integrative approach. More specifically, this dissertation is a combined strategy case study of housing design and provision in Kenya, a sub-Saharan African country with serious shelter problems. A majority of Kenya's urban population lives in slums or squatter settlements. This dissertation covers four major areas of housing design and provision in Kenya: building materials, user preferences for building materials and housing designs, interior layouts, and the organizational context of the housing sector. These four areas are theoretically unified by Canter's (1977) model of place. Each of the first three areas (housing design) relates to one or more of the three domains in the model. The fourth area (housing provision) pertains to the model's context and framework. The technical building materials research reveals the feasibility of making low-cost materials (soil-cements) with satisfactory engineering performance. The research in preference for building materials reveals that the two independent variables, soil and mix, have a significant effect on potential users' ratings. The housing preference study reveals that of the four independent variables, design and type had a significant effect on potential users' ratings, while materials and construction method did not have a significant effect. The interior layout studies reveal important associations between spatial configurations and a key space (the kitchen), and between configuration and conceptualizations of living, cooking, and sleeping spaces. The findings from the studies of preferences and interior layouts are then synthesized in the development of a low-cost housing prototype. Lastly, analysis of the organizational context reveals notable links between nominal housing-related responsibilities, and the potential power and influence of key organizations. The potential effects of the spatial context on housing organizations are also explored. Later, the key organizations are restructured to address shortcomings identified at the organizational and sectoral levels.

An Optimization-Based Approach to Injector Element Design

NASA Technical Reports Server (NTRS)

Tucker, P. Kevin; Shyy, Wei; Vaidyanathan, Rajkumar; Turner, Jim (Technical Monitor)

2000-01-01

An injector optimization methodology, method i, is used to investigate optimal design points for gaseous oxygen/gaseous hydrogen (GO2/GH2) injector elements. A swirl coaxial element and an unlike impinging element (a fuel-oxidizer-fuel triplet) are used to facilitate the study. The elements are optimized in terms of design variables such as fuel pressure drop, APf, oxidizer pressure drop, deltaP(sub f), combustor length, L(sub comb), and full cone swirl angle, theta, (for the swirl element) or impingement half-angle, alpha, (for the impinging element) at a given mixture ratio and chamber pressure. Dependent variables such as energy release efficiency, ERE, wall heat flux, Q(sub w), injector heat flux, Q(sub inj), relative combustor weight, W(sub rel), and relative injector cost, C(sub rel), are calculated and then correlated with the design variables. An empirical design methodology is used to generate these responses for both element types. Method i is then used to generate response surfaces for each dependent variable for both types of elements. Desirability functions based on dependent variable constraints are created and used to facilitate development of composite response surfaces representing the five dependent variables in terms of the input variables. Three examples illustrating the utility and flexibility of method i are discussed in detail for each element type. First, joint response surfaces are constructed by sequentially adding dependent variables. Optimum designs are identified after addition of each variable and the effect each variable has on the element design is illustrated. This stepwise demonstration also highlights the importance of including variables such as weight and cost early in the design process. Secondly, using the composite response surface that includes all five dependent variables, unequal weights are assigned to emphasize certain variables relative to others. Here, method i is used to enable objective trade studies on design issues such as component life and thrust to weight ratio. Finally, combining results from both elements to simulate a trade study, thrust-to-weight trends are illustrated and examined in detail.

Communications terminal breadboard

NASA Technical Reports Server (NTRS)

1972-01-01

A baseline design is presented of a digital communications link between an advanced manned spacecraft (AMS) and an earth terminal via an Intelsat 4 type communications satellite used as a geosynchronous orbiting relay station. The fabrication, integration, and testing of terminal elements at each end of the link are discussed. In the baseline link design, the information carrying capacity of the link was estimated for both the forward direction (earth terminal to AMS) and the return direction, based upon orbital geometry, relay satellite characteristics, terminal characteristics, and the improvement that can be achieved by the use of convolutional coding/Viterbi decoding techniques.

Test-Retest Intervisit Variability of Functional and Structural Parameters in X-Linked Retinoschisis.

PubMed

Jeffrey, Brett G; Cukras, Catherine A; Vitale, Susan; Turriff, Amy; Bowles, Kristin; Sieving, Paul A

2014-09-01

To examine the variability of four outcome measures that could be used to address safety and efficacy in therapeutic trials with X-linked juvenile retinoschisis. Seven men with confirmed mutations in the RS1 gene were evaluated over four visits spanning 6 months. Assessments included visual acuity, full-field electroretinograms (ERG), microperimetric macular sensitivity, and retinal thickness measured by optical coherence tomography (OCT). Eyes were separated into Better or Worse Eye groups based on acuity at baseline. Repeatability coefficients were calculated for each parameter and jackknife resampling used to derive 95% confidence intervals (CIs). The threshold for statistically significant change in visual acuity ranged from three to eight letters. For ERG a-wave, an amplitude reduction greater than 56% would be considered significant. For other parameters, variabilities were lower in the Worse Eye group, likely a result of floor effects due to collapse of the schisis pockets and/or retinal atrophy. The criteria for significant change (Better/Worse Eye) for three important parameters were: ERG b/a-wave ratio (0.44/0.23), point wise sensitivity (10.4/7.0 dB), and central retinal thickness (31%/18%). The 95% CI range for visual acuity, ERG, retinal sensitivity, and central retinal thickness relative to baseline are described for this cohort of participants with X-linked juvenile retinoschisis (XLRS). A quantitative understanding of the variability of outcome measures is vital to establishing the safety and efficacy limits for therapeutic trials of XLRS patients.

A test of safety, violence prevention, and civility climate domain-specific relationships with relevant workplace hazards

PubMed Central

Spector, Paul E.

2016-01-01

Background Safety climate, violence prevention climate, and civility climate were independently developed and linked to domain-specific workplace hazards, although all three were designed to promote the physical and psychological safety of workers. Purpose To test domain specificity between conceptually related workplace climates and relevant workplace hazards. Methods Data were collected from 368 persons employed in various industries and descriptive statistics were calculated for all study variables. Correlational and relative weights analyses were used to test for domain specificity. Results The three climate domains were similarly predictive of most workplace hazards, regardless of domain specificity. Discussion This study suggests that the three climate domains share a common higher order construct that may predict relevant workplace hazards better than any of the scales alone. PMID:27110930

Longevity following the experience of parental divorce.

PubMed

Martin, Leslie R; Friedman, Howard S; Clark, Kathleen M; Tucker, Joan S

2005-11-01

An archival prospective design was used to study mediating and moderating variables for the association between parental divorce and increased mortality risk, using a sub-group (n = 1183) of individuals from the US Terman Life Cycle Study covering the period 1921-2000. In childhood, both socioeconomic status (SES) and family psychosocial environment were related to parental divorce but did little to explain its effects. The higher mortality risk associated with experiencing parental divorce was ameliorated among individuals (especially men) who achieved a sense of personal satisfaction by mid-life. Behaviorally, smoking was the strongest mediator of the divorce-mortality link. This study extends previous work on the long-term effects of parental divorce and reveals some reasons why the stress of parental divorce in childhood need not necessarily lead to negative later-life outcomes.

Design study and performance analysis of a high-speed multistage variable-geometry fan for a variable cycle engine

NASA Technical Reports Server (NTRS)

Sullivan, T. J.; Parker, D. E.

1979-01-01

A design technology study was performed to identify a high speed, multistage, variable geometry fan configuration capable of achieving wide flow modulation with near optimum efficiency at the important operating condition. A parametric screening study of the front and rear block fans was conducted in which the influence of major fan design features on weight and efficiency was determined. Key design parameters were varied systematically to determine the fan configuration most suited for a double bypass, variable cycle engine. Two and three stage fans were considered for the front block. A single stage, core driven fan was studied for the rear block. Variable geometry concepts were evaluated to provide near optimum off design performance. A detailed aerodynamic design and a preliminary mechanical design were carried out for the selected fan configuration. Performance predictions were made for the front and rear block fans.

Emotional Intelligence and its Relationship with Gender, Academic Performance and Intellectual Abilities of Undergraduates

ERIC Educational Resources Information Center

Valadez Sierra, Maria de los Dolores; Borges del Rosal, Maria Africa; Ruvalcaba Romero, Norma; Villegas, Karina; Lorenzo, Maryurena

2013-01-01

Introduction: Emotional intelligence has been linked to several variables, such as gender, and academic performance. In the area of high intellectual abilities, the literature shows controversy, without a unanimous result on the relationship between both variables. In the present study we analyzed the modulatory effect has academic performance in…

A Content Analysis of Acculturation Research in the Career Development Literature

ERIC Educational Resources Information Center

Miller, Matthew J.; Kerlow-Myers, Andrew E.

2009-01-01

The purpose of the present study was to highlight the importance of acculturation as an explanatory variable in career development and to provide an empirical review of acculturation research in the career development literature. Acculturation is a cultural variable that has been linked to a number of important career development outcomes for…

Physically Active Adults: An Analysis of the Key Variables That Keep Them Moving

ERIC Educational Resources Information Center

Downs, Andrew

2016-01-01

Background: A large proportion of adults are insufficiently physically active, and researchers have yet to determine the factors that enable individuals to maintain adequate levels of physical activity throughout adulthood. Purpose: This study sought to identify the key variables linked with consistent physical activity in adulthood as elucidated…

Wandering Minds and Wavering Rhythms: Linking Mind Wandering and Behavioral Variability

ERIC Educational Resources Information Center

Seli, Paul; Cheyne, James Allan; Smilek, Daniel

2013-01-01

Mind wandering is a pervasive feature of human cognition often associated with the withdrawal of task-related executive control processes. Here, we explore the possibility that, in tasks requiring executive control to sustain consistent responding, moments of mind wandering could be associated with moments of increased behavioral variability. To…

Influences on the Intention to Enter Higher Education: The Importance of Expected Returns

ERIC Educational Resources Information Center

Menon, Maria Eliophotou; Markadjis, Elias; Theodoropoulos, Nikolaos; Socratous, Michalis

2017-01-01

Research points to several determinants of the private demand for higher education, which include individual, social, economic, and institutional variables. Of these variables, economic factors are considered to be highly relevant, especially in the current financial crisis. The paper investigates the link between expected rates of return to…

Something for nothing: understanding purchasing behaviors in social virtual environments.

PubMed

Chung, Donghun

2005-12-01

The present paper is composed of two studies. The first study explored the variables influencing the purchase of avatar-related products through the avatar users' survey research. This proposed a theoretical model of the purchase of avatar-related products using attitude toward an avatar, subjective norm, self-presentation, identification, and immersion. Although significant relationships were found for the individual links, the model was not supported. The second study focused on which variables predict the intention to use avatar-related products. A model was tested with avatar non-users. Results indicated that all relationships among variables in the Technology Acceptance Model (TAM), such as perceived ease of use of avatar, perceived usefulness of avatar, attitude toward using avatar, and intention to use avatar-related products, were strongly supported, as was the link between Internet self-efficacy and perceived ease of use of avatar. Also, the peer groups' subjective norm component which was a unique variable successfully predicted intention to use avatar-related products. Overall, all hypotheses were supported and the data were judged to be consistent with the model.

Price of anarchy on heterogeneous traffic-flow networks.

PubMed

Rose, A; O'Dea, R; Hopcraft, K I

2016-09-01

The efficiency of routing traffic through a network, comprising nodes connected by links whose cost of traversal is either fixed or varies in proportion to volume of usage, can be measured by the "price of anarchy." This is the ratio of the cost incurred by agents who act to minimize their individual expenditure to the optimal cost borne by the entire system. As the total traffic load and the network variability-parameterized by the proportion of variable-cost links in the network-changes, the behaviors that the system presents can be understood with the introduction of a network of simpler structure. This is constructed from classes of nonoverlapping paths connecting source to destination nodes that are characterized by the number of variable-cost edges they contain. It is shown that localized peaks in the price of anarchy occur at critical traffic volumes at which it becomes beneficial to exploit ostensibly more expensive paths as the network becomes more congested. Simulation results verifying these findings are presented for the variation of the price of anarchy with the network's size, aspect ratio, variability, and traffic load.

General split helicity gluon tree amplitudes in open twistor string theory

NASA Astrophysics Data System (ADS)

Dolan, Louise; Goddard, Peter

2010-05-01

We evaluate all split helicity gluon tree amplitudes in open twistor string theory. We show that these amplitudes satisfy the BCFW recurrence relations restricted to the split helicity case and, hence, that these amplitudes agree with those of gauge theory. To do this we make a particular choice of the sextic constraints in the link variables that determine the poles contributing to the contour integral expression for the amplitudes. Using the residue theorem to re-express this integral in terms of contributions from poles at rational values of the link variables, which we determine, we evaluate the amplitudes explicitly, regaining the gauge theory results of Britto et al. [25].

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brewer, Forrest; Incandela, Joseph

This project was slated to design and develop Rad-Hard IP components for 1Gb/s links and supporting hardware designs such as PLL, SER/DES, pad drivers and receivers and custom protocol hardware for the 1Gb/s channel. Also included in the proposal was a study of a hardened memory to be used as a packet buffer for channel and data concentrator components to meet the 1 Gb/s specification. Over the course of the proposal, technology change and innovation of hardware designs lead us away from the 1 Gb/s goal to contemplate much higher performance link IP which, we believed better met the goalsmore » of physics experiments. Note that CERN microelectronics had managed to create a 4.7 Gb/s link designed to drive optical fibers and containing infrastructure for connecting much lower bandwidth front-end devices. Our own work to that point had shown the possibility of constructing a link with much lower power, lower physical overhead but of equivalent performance that could be designed to integrate directly onto the front-end ASIC (ADC and data encoding) designs. Substantial overall power savings and experimental simplicity could be achieved by eliminating data transmission to data concentrators and data concentrators and related hardened buffering themselves, with conversion to optical media at a removed distance from the experiment core. We had already developed and tested Rad-Hard SER/DES components (1Gb in 130nm standard cells) and redundant Pad Drivers/Receivers (3+ Gb/s designed and measured performance), and had a viable 1Gb/s link design based on redundant a stuttered clock receiver and classical PLL, so the basic goals of the proposal had been achieved. Below, in chronological order, are the products and tools we constructed, as well as our tests and publications.« less

Integrating impact evaluation in the design and implementation of monitoring marine protected areas

PubMed Central

Ahmadia, Gabby N.; Glew, Louise; Provost, Mikaela; Gill, David; Hidayat, Nur Ismu; Mangubhai, Sangeeta; Purwanto; Fox, Helen E.

2015-01-01

Quasi-experimental impact evaluation approaches, which enable scholars to disentangle effects of conservation interventions from broader changes in the environment, are gaining momentum in the conservation sector. However, rigorous impact evaluation using statistical matching techniques to estimate the counterfactual have yet to be applied to marine protected areas (MPAs). While there are numerous studies investigating ‘impacts’ of MPAs that have generated considerable insights, results are variable. This variation has been linked to the biophysical and social context in which they are established, as well as attributes of management and governance. To inform decisions about MPA placement, design and implementation, we need to expand our understanding of conditions under which MPAs are likely to lead to positive outcomes by embracing advances in impact evaluation methodologies. Here, we describe the integration of impact evaluation within an MPA network monitoring programme in the Bird's Head Seascape, Indonesia. Specifically we (i) highlight the challenges of implementation ‘on the ground’ and in marine ecosystems and (ii) describe the transformation of an existing monitoring programme into a design appropriate for impact evaluation. This study offers one potential model for mainstreaming impact evaluation in the conservation sector. PMID:26460128

An Investigation of Synchrony in Transport Networks

NASA Technical Reports Server (NTRS)

Kincaid, Rex K.; Alexandrov, Natalia M.; Holroyd, Michael J.

2007-01-01

The cumulative degree distributions of transport networks, such as air transportation networks and respiratory neuronal networks, follow power laws. The significance of power laws with respect to other network performance measures, such as throughput and synchronization, remains an open question. Evolving methods for the analysis and design of air transportation networks must address network performance in the face of increasing demands and the need to contain and control local network disturbances, such as congestion. Toward this end, we investigate functional relationships that govern the performance of transport networks; for example, the links between the first nontrivial eigenvalue of a network's Laplacian matrix - a quantitative measure of network synchronizability - and other global network parameters. In particular, among networks with a fixed degree distribution and fixed network assortativity (a measure of a network's preference to attach nodes based on a similarity or difference), those with the small eigenvalue are shown to be poor synchronizers, to have much longer shortest paths and to have greater clustering in comparison to those with large. A simulation of a respiratory network adds data to our investigation. This study is a beginning step in developing metrics and design variables for the analysis and active design of air transport networks.

Rapidly variable relatvistic absorption

NASA Astrophysics Data System (ADS)

Parker, M.; Pinto, C.; Fabian, A.; Lohfink, A.; Buisson, D.; Alston, W.; Jiang, J.

2017-10-01

I will present results from the 1.5Ms XMM-Newton observing campaign on the most X-ray variable AGN, IRAS 13224-3809. We find a series of nine absorption lines with a velocity of 0.24c from an ultra-fast outflow. For the first time, we are able to see extremely rapid variability of the UFO features, and can link this to the X-ray variability from the inner accretion disk. We find a clear flux dependence of the outflow features, suggesting that the wind is ionized by increasing X-ray emission.

Towards the Rational Design of a Candidate Vaccine against Pregnancy Associated Malaria: Conserved Sequences of the DBL6ε Domain of VAR2CSA

PubMed Central

Badaut, Cyril; Bertin, Gwladys; Rustico, Tatiana; Fievet, Nadine; Massougbodji, Achille; Gaye, Alioune; Deloron, Philippe

2010-01-01

Background Placental malaria is a disease linked to the sequestration of Plasmodium falciparum infected red blood cells (IRBC) in the placenta, leading to reduced materno-fetal exchanges and to local inflammation. One of the virulence factors of P. falciparum involved in cytoadherence to chondroitin sulfate A, its placental receptor, is the adhesive protein VAR2CSA. Its localisation on the surface of IRBC makes it accessible to the immune system. VAR2CSA contains six DBL domains. The DBL6ε domain is the most variable. High variability constitutes a means for the parasite to evade the host immune response. The DBL6ε domain could constitute a very attractive basis for a vaccine candidate but its reported variability necessitates, for antigenic characterisations, identifying and classifying commonalities across isolates. Methodology/Principal Findings Local alignment analysis of the DBL6ε domain had revealed that it is not as variable as previously described. Variability is concentrated in seven regions present on the surface of the DBL6ε domain. The main goal of our work is to classify and group variable sequences that will simplify further research to determine dominant epitopes. Firstly, variable sequences were grouped following their average percent pairwise identity (APPI). Groups comprising many variable sequences sharing low variability were found. Secondly, ELISA experiments following the IgG recognition of a recombinant DBL6ε domain, and of peptides mimicking its seven variable blocks, allowed to determine an APPI cut-off and to isolate groups represented by a single consensus sequence. Conclusions/Significance A new sequence approach is used to compare variable regions in sequences that have extensive segmental gene relationship. Using this approach, the VAR2CSA DBL6 domain is composed of 7 variable blocks with limited polymorphism. Each variable block is composed of a limited number of consensus types. Based on peptide based ELISA, variable blocks with 85% or greater sequence identity are expected to be recognized equally well by antibody and can be considered the same consensus type. Therefore, the analysis of the antibody response against the classified small number of sequences should be helpful to determine epitopes. PMID:20585655

Adaptation of the Camera Link Interface for Flight-Instrument Applications

NASA Technical Reports Server (NTRS)

Randall, David P.; Mahoney, John C.

2010-01-01

COTS (commercial-off-the-shelf) hard ware using an industry-standard Camera Link interface is proposed to accomplish the task of designing, building, assembling, and testing electronics for an airborne spectrometer that would be low-cost, but sustain the required data speed and volume. The focal plane electronics were designed to support that hardware standard. Analysis was done to determine how these COTS electronics could be interfaced with space-qualified camera electronics. Interfaces available for spaceflight application do not support the industry standard Camera Link interface, but with careful design, COTS EGSE (electronics ground support equipment), including camera interfaces and camera simulators, can still be used.

Experiment definition phase shuttle laboratory LDRL-10.6 experiment. [using a molniya satellite and ground communication links

NASA Technical Reports Server (NTRS)

1975-01-01

The acquisition and tracking links of shuttle to molniya satellite and shuttle to ground are established. Link parameters and tolerance are analyzed. A 10-micromillimeter optomechanical subsystem brassboard model was designed and measured for optical properties and weight optimization. The design incorporates an afocal rotating Gregorian telescope in a two-gimbal berylium structure with beam steering control mechanisms. Parameters for both the optomechanical subsystem and spaceborne terminals are included.

The Development of an Expert System for the Creative Design of Mechanisms

DTIC Science & Technology

1989-06-26

adjacelnt Link-1 Figue 41 B.Semntc newr-bae knowlede representto cee 25 4.3 Planning Control in Mechanism Design In a "plain", rule-based expert system...the contracted level, ensures the non-crossing feature. 2. Geometrical: handled at the monochrome level, manages the approximate size of links. 3...Ornamental: handled at the colored level, manages proper orientations between binary links and other miscellaneous appearance of the sketch. Each stage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayes, T.; Smith, K.S.; Severino, F.

A critical capability of the new RHIC low level rf (LLRF) system is the ability to synchronize signals across multiple locations. The 'Update Link' provides this functionality. The 'Update Link' is a deterministic serial data link based on the Xilinx RocketIO protocol that is broadcast over fiber optic cable at 1 gigabit per second (Gbps). The link provides timing events and data packets as well as time stamp information for synchronizing diagnostic data from multiple sources. The new RHIC LLRF was designed to be a flexible, modular system. The system is constructed of numerous independent RF Controller chassis. To providemore » synchronization among all of these chassis, the Update Link system was designed. The Update Link system provides a low latency, deterministic data path to broadcast information to all receivers in the system. The Update Link system is based on a central hub, the Update Link Master (ULM), which generates the data stream that is distributed via fiber optic links. Downstream chassis have non-deterministic connections back to the ULM that allow any chassis to provide data that is broadcast globally.« less

Performance analysis of rain attenuation on earth-to-satellite microwave links design in Libya

NASA Astrophysics Data System (ADS)

Rafiqul Islam, Md; Hussein Budalal, Asma Ali; Habaebi, Mohamed H.; Badron, Khairayu; Fadzil Ismail, Ahmad

2017-11-01

Performances of earth-to-satellite microwave links operating in Ku, Ka, and V-bands are degraded by the environment and strongly attenuated by rain. Rain attenuation is the most significant consideration and challenge to design a reliable earth-to-satellite microwave links for these frequency bands. Hence, it is essential for satellite link designer to take into account rain fade margin accurately before system implementation. Rain rate is the main measured parameter to predict of rain attenuation. Rainfall statistical data measured and recorded in Libya for the period of 30 years are collected from 5 locations. The prediction methods require one minute integration time rain intensity. Therefore, collected data were analyzed and processed to convert into one-minute rain rate cumulative distribution in Libya. The model proposed by ITU-R is used to predict and investigate rain fade based on converted 1-minute rain rate data. Rain fade predicted at two locations are used for performance analysis in terms of link spectral efficiency and throughput. V-band downlink shows that 99.99% availability is possible in all the Southern part stations in Libya at 0.29 bps/Hz spectral efficiency and 20.74 Mbps throughput when 72 MHz transponder band width is used which is not feasible in Northern part. Results of this paper will be a very useful resource to design highly reliable earth-to-satellite communication links in Libya.

Effect analysis of design variables on the disc in a double-eccentric butterfly valve.

PubMed

Kang, Sangmo; Kim, Da-Eun; Kim, Kuk-Kyeom; Kim, Jun-Oh

2014-01-01

We have performed a shape optimization of the disc in an industrial double-eccentric butterfly valve using the effect analysis of design variables to enhance the valve performance. For the optimization, we select three performance quantities such as pressure drop, maximum stress, and mass (weight) as the responses and three dimensions regarding the disc shape as the design variables. Subsequently, we compose a layout of orthogonal array (L16) by performing numerical simulations on the flow and structure using a commercial package, ANSYS v13.0, and then make an effect analysis of the design variables on the responses using the design of experiments. Finally, we formulate a multiobjective function consisting of the three responses and then propose an optimal combination of the design variables to maximize the valve performance. Simulation results show that the disc thickness makes the most significant effect on the performance and the optimal design provides better performance than the initial design.

Dependency, democracy, and infant mortality: a quantitative, cross-national analysis of less developed countries.

PubMed

Shandra, John M; Nobles, Jenna; London, Bruce; Williamson, John B

2004-07-01

This study presents quantitative, sociological models designed to account for cross-national variation in infant mortality rates. We consider variables linked to four different theoretical perspectives: the economic modernization, social modernization, political modernization, and dependency perspectives. The study is based on a panel regression analysis of a sample of 59 developing countries. Our preliminary analysis based on additive models replicates prior studies to the extent that we find that indicators linked to economic and social modernization have beneficial effects on infant mortality. We also find support for hypotheses derived from the dependency perspective suggesting that multinational corporate penetration fosters higher levels of infant mortality. Subsequent analysis incorporating interaction effects suggest that the level of political democracy conditions the effects of dependency relationships based upon exports, investments from multinational corporations, and international lending institutions. Transnational economic linkages associated with exports, multinational corporations, and international lending institutions adversely affect infant mortality more strongly at lower levels of democracy than at higher levels of democracy: intranational, political factors interact with the international, economic forces to affect infant mortality. We conclude with some brief policy recommendations and suggestions for the direction of future research.

Remote sensing and spatial statistical techniques for modelling Ommatissus lybicus (Hemiptera: Tropiduchidae) habitat and population densities

PubMed Central

Kwan, Paul; Welch, Mitchell

2017-01-01

In order to understand the distribution and prevalence of Ommatissus lybicus (Hemiptera: Tropiduchidae) as well as analyse their current biographical patterns and predict their future spread, comprehensive and detailed information on the environmental, climatic, and agricultural practices are essential. The spatial analytical techniques such as Remote Sensing and Spatial Statistics Tools, can help detect and model spatial links and correlations between the presence, absence and density of O. lybicus in response to climatic, environmental, and human factors. The main objective of this paper is to review remote sensing and relevant analytical techniques that can be applied in mapping and modelling the habitat and population density of O. lybicus. An exhaustive search of related literature revealed that there are very limited studies linking location-based infestation levels of pests like the O. lybicus with climatic, environmental, and human practice related variables. This review also highlights the accumulated knowledge and addresses the gaps in this area of research. Furthermore, it makes recommendations for future studies, and gives suggestions on monitoring and surveillance methods in designing both local and regional level integrated pest management strategies of palm tree and other affected cultivated crops. PMID:28875085

Remote sensing and spatial statistical techniques for modelling Ommatissus lybicus (Hemiptera: Tropiduchidae) habitat and population densities.

PubMed

Al-Kindi, Khalifa M; Kwan, Paul; R Andrew, Nigel; Welch, Mitchell

2017-01-01

In order to understand the distribution and prevalence of Ommatissus lybicus (Hemiptera: Tropiduchidae) as well as analyse their current biographical patterns and predict their future spread, comprehensive and detailed information on the environmental, climatic, and agricultural practices are essential. The spatial analytical techniques such as Remote Sensing and Spatial Statistics Tools, can help detect and model spatial links and correlations between the presence, absence and density of O. lybicus in response to climatic, environmental, and human factors. The main objective of this paper is to review remote sensing and relevant analytical techniques that can be applied in mapping and modelling the habitat and population density of O. lybicus . An exhaustive search of related literature revealed that there are very limited studies linking location-based infestation levels of pests like the O. lybicus with climatic, environmental, and human practice related variables. This review also highlights the accumulated knowledge and addresses the gaps in this area of research. Furthermore, it makes recommendations for future studies, and gives suggestions on monitoring and surveillance methods in designing both local and regional level integrated pest management strategies of palm tree and other affected cultivated crops.

The Impact of Continuous Medicaid Enrollment on Diagnosis, Treatment, and Survival in Six Surgical Cancers

PubMed Central

Dawes, Aaron J; Louie, Rachel; Nguyen, David K; Maggard-Gibbons, Melinda; Parikh, Punam; Ettner, Susan L; Ko, Clifford Y; Zingmond, David S

2014-01-01

Objective To examine the effect of Medicaid enrollment on the diagnosis, treatment, and survival of six surgically relevant cancers among poor and underserved Californians. Data Sources California Cancer Registry (CCR), California's Patient Discharge Database (PDD), and state Medicaid enrollment files between 2002 and 2008. Study Design We linked clinical and administrative records to differentiate patients continuously enrolled in Medicaid from those receiving coverage at the time of their cancer diagnosis. We developed multivariate logistic regression models to predict death within 1 year for each cancer after controlling for sociodemographic and clinical variables. Data Collection/Extraction Methods All incident cases of six cancers (colon, esophageal, lung, pancreas, stomach, and ovarian) were identified from CCR. CCR records were linked to hospitalizations (PDD) and monthly Medicaid enrollment. Principal Findings Continuous enrollment in Medicaid for at least 6 months prior to diagnosis improves survival in three surgically relevant cancers. Discontinuous Medicaid patients have higher stage tumors, undergo fewer definitive operations, and are more likely to die even after risk adjustment. Conclusions Expansion of continuous insurance coverage under the Affordable Care Act is likely to improve both access and clinical outcomes for cancer patients in California. PMID:25256223

Iterative Bayesian Estimation of Travel Times on Urban Arterials: Fusing Loop Detector and Probe Vehicle Data.

PubMed

Liu, Kai; Cui, Meng-Ying; Cao, Peng; Wang, Jiang-Bo

2016-01-01

On urban arterials, travel time estimation is challenging especially from various data sources. Typically, fusing loop detector data and probe vehicle data to estimate travel time is a troublesome issue while considering the data issue of uncertain, imprecise and even conflicting. In this paper, we propose an improved data fusing methodology for link travel time estimation. Link travel times are simultaneously pre-estimated using loop detector data and probe vehicle data, based on which Bayesian fusion is then applied to fuse the estimated travel times. Next, Iterative Bayesian estimation is proposed to improve Bayesian fusion by incorporating two strategies: 1) substitution strategy which replaces the lower accurate travel time estimation from one sensor with the current fused travel time; and 2) specially-designed conditions for convergence which restrict the estimated travel time in a reasonable range. The estimation results show that, the proposed method outperforms probe vehicle data based method, loop detector based method and single Bayesian fusion, and the mean absolute percentage error is reduced to 4.8%. Additionally, iterative Bayesian estimation performs better for lighter traffic flows when the variability of travel time is practically higher than other periods.

Iterative Bayesian Estimation of Travel Times on Urban Arterials: Fusing Loop Detector and Probe Vehicle Data

PubMed Central

Cui, Meng-Ying; Cao, Peng; Wang, Jiang-Bo

2016-01-01

On urban arterials, travel time estimation is challenging especially from various data sources. Typically, fusing loop detector data and probe vehicle data to estimate travel time is a troublesome issue while considering the data issue of uncertain, imprecise and even conflicting. In this paper, we propose an improved data fusing methodology for link travel time estimation. Link travel times are simultaneously pre-estimated using loop detector data and probe vehicle data, based on which Bayesian fusion is then applied to fuse the estimated travel times. Next, Iterative Bayesian estimation is proposed to improve Bayesian fusion by incorporating two strategies: 1) substitution strategy which replaces the lower accurate travel time estimation from one sensor with the current fused travel time; and 2) specially-designed conditions for convergence which restrict the estimated travel time in a reasonable range. The estimation results show that, the proposed method outperforms probe vehicle data based method, loop detector based method and single Bayesian fusion, and the mean absolute percentage error is reduced to 4.8%. Additionally, iterative Bayesian estimation performs better for lighter traffic flows when the variability of travel time is practically higher than other periods. PMID:27362654

Engineering and characterization of fluorogenic glycine riboswitches

PubMed Central

Ketterer, Simon; Gladis, Lukas; Kozica, Adnan; Meier, Matthias

2016-01-01

A set of 12 fluorogenic glycine riboswitches with different thermodynamic and kinetic response properties was engineered. For the design of functional riboswitches, a three-part RNA approach was applied based on the idea of linking a RNA sensor, transmitter and actuator part together. For the RNA sensor and actuator part, we used the tandem glycine aptamer structure from Bacillus subtillis, and fluorogenic aptamer Spinach, respectively. To achieve optimal signal transduction from the sensor to the actuator, a riboswitch library with variable transmitter was screened with a microfluidic large-scale integration chip. This allowed us to establish the complete thermodynamic binding profiles of the riboswitch library. Glycine dissociation constants of the 12 strong fluorescence response riboswitches varied between 99.7 and 570 μM. Furthermore, the kinetic glycine binding (kon), and dissociation (koff) rates, and corresponding energy barriers of the 10 strongest fluorescence response riboswitches were determined with the same chip platform. kon and koff were in the order of 10−3s−1 and 10−2s−1, respectively. Conclusively, we demonstrate that systematic screening of synthetic and natural linked RNA parts with microfluidic chip technology is an effective approach to rapidly generate fluorogenic metabolite riboswitches with a broad range of biophysical response properties. PMID:27220466

Toward an evidence-based patient-provider communication in rehabilitation: linking communication elements to better rehabilitation outcomes.

PubMed

Jesus, Tiago Silva; Silva, Isabel Lopes

2016-04-01

There is a growing interest in linking aspects of patient-provider communication to rehabilitation outcomes. However, the field lacks a conceptual understanding on: (a) 'how' rehabilitation outcomes can be improved by communication; and (b) through 'which' elements in particular. This article elaborates on the conceptual developments toward informing further practice and research. Existing models of communication in healthcare were adapted to rehabilitation, and its outcomes through a comprehensive literature review. After depicting mediating mechanisms and variables (e.g. therapeutic engagement, adjustment toward disability), this article presents the '4 Rehab Communication Elements' deemed likely to underpin rehabilitation outcomes. The four elements are: (a) knowing the person and building a supportive relationship; (b) effective information exchange and education; (c) shared goal-setting and action planning; and (d) fostering a more positive, yet realistic, cognitive and self-reframing. This article describes an unprecedented, outcomes-oriented approach toward the design of rehabilitation communication, which has resulted in the development of a new intervention model: the '4 Rehab Communication Elements'. Further trials are needed to evaluate the impact of this whole intervention model on rehabilitation outcomes. © The Author(s) 2015.

Change-related expectations and commitment to change of nurses: the role of leadership and communication.

PubMed

Portoghese, Igor; Galletta, Maura; Battistelli, Adalgisa; Saiani, Luisa; Penna, Maria Pietronilla; Allegrini, Elisabetta

2012-07-01

The purpose of this study was to test a theoretical model linking the impact of expectations on commitment to change and to explore whether change-related communication is a mediating variable between leader-member exchange and expectations. Expectations for change outcomes are an important condition to increase nurses' commitment to change. To understand the role of leadership and communication in expectations development is crucial to promote commitment to change. A predictive, non-experimental design was used in a random sample of 395 nurses. Structural equation modelling was used to analyse the hypothesized model. Positive expectations had a direct effect on affective commitment to change, whereas negative expectation had a direct effect on continuance commitment to change. Leader-member exchange and communication influenced nurse's expectations about change. Communication partially mediated the relationship between Leader-member exchange and expectations. These findings suggested that nurses' expectation about change were strongly linked to commitment to change. Furthermore, the enhancement of communication and relationship with leader contributed to the development of positive and negative expectations. Strategies to promote commitment to change include developing positive expectations about change outcomes and building high-quality leadership style oriented to the communication. © 2011 Blackwell Publishing Ltd.

Dynamic rain fade compensation techniques for the advanced communications technology satellite

NASA Technical Reports Server (NTRS)

Manning, Robert M.

1992-01-01

The dynamic and composite nature of propagation impairments that are incurred on earth-space communications links at frequencies in and above the 30/20 GHz Ka band necessitate the use of dynamic statistical identification and prediction processing of the fading signal in order to optimally estimate and predict the levels of each of the deleterious attenuation components. Such requirements are being met in NASA's Advanced Communications Technology Satellite (ACTS) project by the implementation of optimal processing schemes derived through the use of the ACTS Rain Attenuation Prediction Model and nonlinear Markov filtering theory. The ACTS Rain Attenuation Prediction Model discerns climatological variations on the order of 0.5 deg in latitude and longitude in the continental U.S. The time-dependent portion of the model gives precise availability predictions for the 'spot beam' links of ACTS. However, the structure of the dynamic portion of the model, which yields performance parameters such as fade duration probabilities, is isomorphic to the state-variable approach of stochastic control theory and is amenable to the design of such statistical fade processing schemes which can be made specific to the particular climatological location at which they are employed.

Anti-buckling design of variable stiffness composite cylinder under combined loading based on the multi-objective optimization method

NASA Astrophysics Data System (ADS)

Zheng, Y.; Chen, J.

2018-06-01

Variable stiffness composite structures take full advantages of composite’s design ability. An enlarged design space will make the structure’s performance more excellent. Through an optimal design of a variable stiffness cylinder, the buckling capacity of the cylinder will be increased as compared with its constant stiffness counterpart. In this paper, variable stiffness composite cylinders sustaining combined loadings are considered, and the optimization is conducted based on the multi-objective optimization method. The results indicate that variable stiffness cylinder’s loading capacity is increased significantly as compared with the constant stiffness, especially when an inhomogeneous loading is considered.

Stress contagion in the classroom? The link between classroom teacher burnout and morning cortisol in elementary school students.

PubMed

Oberle, Eva; Schonert-Reichl, Kimberly A

2016-06-01

The purpose of this study was to explore the link between classroom teachers' burnout levels and students' physiological stress response. Drawing from a stress-contagion framework, we expected higher levels of teacher burnout to be related to elevated cortisol levels in elementary school students (N = 406, 50% female, Mean age = 11.26, SD = .89). Classroom teacher burnout was assessed with the Maslach Burnout Inventory modified for teachers. Salivary cortisol was collected as an indicator of students' hypothalamic-pituitary-adrenal (HPA) functioning. We collected salivary cortisol in children at 9 a.m., 11:30 a.m., and 2 p.m. in the classroom setting. Using Multilevel Modeling, we found that children's morning cortisol levels significantly varied between classrooms (10% variability). Higher levels of classroom teacher burnout significantly predicted the variability in morning cortisol. Teacher burnout reduced the unexplained variability in cortisol at the classroom level to 4.6%. This is the first study to show that teachers' occupational stress is linked to students' physiological stress regulation. We discuss the present findings in the context of potential stress contagion in the classroom, considering empirical and practical relevance. Copyright © 2016 Elsevier Ltd. All rights reserved.

Value of Conditioned Reinforcers as a Function of Temporal Context

ERIC Educational Resources Information Center

O'Daly, Matthew; Meyer, Steven; Fantino, Edmund

2005-01-01

In two experiments, pigeons were trained on a multiple-chain schedule, in which the initial link for one chain was a variable-interval (VI) 100s schedule and for the other chain a VI 10s schedule. The terminal links were both fixed-time 30s schedules signaled by differently colored stimuli. Following training, the pigeons had their preference for…

Factors Influencing the Link between Social Anxiety and Peer Acceptance: Contributions of Social Skills and Close Friendships during Middle Childhood

ERIC Educational Resources Information Center

Greco, Laurie A.; Morris, Tracy L.

2005-01-01

Childhood social anxiety consistently has been linked with low levels of peer acceptance, yet little is known about the factors contributing to this association. We therefore examined the mediating and moderating role of social skills and close friendships, two conceptually and empirically relevant variables which were hypothesized to contribute…

Addressing climate change in the Forest Vegetation Simulator to assess impacts on landscape forest dynamics

Treesearch

Nicholas L. Crookston; Gerald E. Rehfeldt; Gary E. Dixon; Aaron R. Weiskittel

2010-01-01

To simulate stand-level impacts of climate change, predictors in the widely used Forest Vegetation Simulator (FVS) were adjusted to account for expected climate effects. This was accomplished by: (1) adding functions that link mortality and regeneration of species to climate variables expressing climatic suitability, (2) constructing a function linking site index to...

Addressing climate change in the forest vegetation simulator to assess impacts on landscape forest dynamics

Treesearch

Nicholas L. Crookston; Gerald E. Rehfeldt; Gary E. Dixon; Aaron R. Weiskittel

2010-01-01

To simulate stand-level impacts of climate change, predictors in the widely used Forest Vegetation Simulator (FVS) were adjusted to account for expected climate effects. This was accomplished by: (1) adding functions that link mortality and regeneration of species to climate variables expressing climatic suitability, (2) constructing a function linking site index to...

Combined model of intrinsic and extrinsic variability for computational network design with application to synthetic biology.

PubMed

Toni, Tina; Tidor, Bruce

2013-01-01

Biological systems are inherently variable, with their dynamics influenced by intrinsic and extrinsic sources. These systems are often only partially characterized, with large uncertainties about specific sources of extrinsic variability and biochemical properties. Moreover, it is not yet well understood how different sources of variability combine and affect biological systems in concert. To successfully design biomedical therapies or synthetic circuits with robust performance, it is crucial to account for uncertainty and effects of variability. Here we introduce an efficient modeling and simulation framework to study systems that are simultaneously subject to multiple sources of variability, and apply it to make design decisions on small genetic networks that play a role of basic design elements of synthetic circuits. Specifically, the framework was used to explore the effect of transcriptional and post-transcriptional autoregulation on fluctuations in protein expression in simple genetic networks. We found that autoregulation could either suppress or increase the output variability, depending on specific noise sources and network parameters. We showed that transcriptional autoregulation was more successful than post-transcriptional in suppressing variability across a wide range of intrinsic and extrinsic magnitudes and sources. We derived the following design principles to guide the design of circuits that best suppress variability: (i) high protein cooperativity and low miRNA cooperativity, (ii) imperfect complementarity between miRNA and mRNA was preferred to perfect complementarity, and (iii) correlated expression of mRNA and miRNA--for example, on the same transcript--was best for suppression of protein variability. Results further showed that correlations in kinetic parameters between cells affected the ability to suppress variability, and that variability in transient states did not necessarily follow the same principles as variability in the steady state. Our model and findings provide a general framework to guide design principles in synthetic biology.

Combined Model of Intrinsic and Extrinsic Variability for Computational Network Design with Application to Synthetic Biology

PubMed Central

Toni, Tina; Tidor, Bruce

2013-01-01

Biological systems are inherently variable, with their dynamics influenced by intrinsic and extrinsic sources. These systems are often only partially characterized, with large uncertainties about specific sources of extrinsic variability and biochemical properties. Moreover, it is not yet well understood how different sources of variability combine and affect biological systems in concert. To successfully design biomedical therapies or synthetic circuits with robust performance, it is crucial to account for uncertainty and effects of variability. Here we introduce an efficient modeling and simulation framework to study systems that are simultaneously subject to multiple sources of variability, and apply it to make design decisions on small genetic networks that play a role of basic design elements of synthetic circuits. Specifically, the framework was used to explore the effect of transcriptional and post-transcriptional autoregulation on fluctuations in protein expression in simple genetic networks. We found that autoregulation could either suppress or increase the output variability, depending on specific noise sources and network parameters. We showed that transcriptional autoregulation was more successful than post-transcriptional in suppressing variability across a wide range of intrinsic and extrinsic magnitudes and sources. We derived the following design principles to guide the design of circuits that best suppress variability: (i) high protein cooperativity and low miRNA cooperativity, (ii) imperfect complementarity between miRNA and mRNA was preferred to perfect complementarity, and (iii) correlated expression of mRNA and miRNA – for example, on the same transcript – was best for suppression of protein variability. Results further showed that correlations in kinetic parameters between cells affected the ability to suppress variability, and that variability in transient states did not necessarily follow the same principles as variability in the steady state. Our model and findings provide a general framework to guide design principles in synthetic biology. PMID:23555205

Variable slew-rate spiral design: theory and application to peak B(1) amplitude reduction in 2D RF pulse design.

PubMed

Xu, Dan; King, Kevin F; Liang, Zhi-Pei

2007-10-01

A new class of spiral trajectories called variable slew-rate spirals is proposed. The governing differential equations for a variable slew-rate spiral are derived, and both numeric and analytic solutions to the equations are given. The primary application of variable slew-rate spirals is peak B(1) amplitude reduction in 2D RF pulse design. The reduction of peak B(1) amplitude is achieved by changing the gradient slew-rate profile, and gradient amplitude and slew-rate constraints are inherently satisfied by the design of variable slew-rate spiral gradient waveforms. A design example of 2D RF pulses is given, which shows that under the same hardware constraints the RF pulse using a properly chosen variable slew-rate spiral trajectory can be much shorter than that using a conventional constant slew-rate spiral trajectory, thus having greater immunity to resonance frequency offsets.

Optimal lay-up design of variable stiffness laminated composite plates by a layer-wise optimization technique

NASA Astrophysics Data System (ADS)

Houmat, A.

2018-02-01

The optimal lay-up design for the maximum fundamental frequency of variable stiffness laminated composite plates is investigated using a layer-wise optimization technique. The design variables are two fibre orientation angles per ply. Thin plate theory is used in conjunction with a p-element to calculate the fundamental frequencies of symmetrically and antisymmetrically laminated composite plates. Comparisons with existing optimal solutions for constant stiffness symmetrically laminated composite plates show excellent agreement. It is observed that the maximum fundamental frequency can be increased considerably using variable stiffness design as compared to constant stiffness design. In addition, optimal lay-ups for the maximum fundamental frequency of variable stiffness symmetrically and antisymmetrically laminated composite plates with different aspect ratios and various combinations of free, simply supported and clamped edge conditions are presented. These should prove a useful benchmark for optimal lay-ups of variable stiffness laminated composite plates.

Non-neural BOLD variability in block and event-related paradigms.

PubMed

Kannurpatti, Sridhar S; Motes, Michael A; Rypma, Bart; Biswal, Bharat B

2011-01-01

Block and event-related stimulus designs are typically used in fMRI studies depending on the importance of detection power or estimation efficiency. The extent of vascular contribution to variability in block and event-related fMRI-BOLD response is not known. With scaling, the extent of vascular variability in the fMRI-BOLD response during block and event-related design tasks was investigated. Blood oxygen level-dependent (BOLD) contrast data from healthy volunteers performing a block design motor task and an event-related memory task requiring performance of a motor response were analyzed from the regions of interest (ROIs) surrounding the primary and supplementary motor cortices. Average BOLD signal change was significantly larger during the block design compared to the event-related design. In each subject, BOLD signal change across voxels in the ROIs had higher variation during the block design task compared to the event-related design task. Scaling using the resting state fluctuation of amplitude (RSFA) and breath-hold (BH), which minimizes BOLD variation due to vascular origins, reduced the within-subject BOLD variability in every subject during both tasks but significantly reduced BOLD variability across subjects only during the block design task. The strong non-neural source of intra- and intersubject variability of BOLD response during the block design compared to event-related task indicates that study designs optimizing for statistical power through enhancement of the BOLD contrast (for, e.g., block design) can be affected by enhancement of non-neural sources of BOLD variability. Copyright © 2011. Published by Elsevier Inc.

Developing and Implementing an Assessment Technique to Measure Linked Concepts

ERIC Educational Resources Information Center

Ye, Li; Oueini, Razanne; Lewis, Scott E.

2015-01-01

The links students make among chemistry content is considered essential for a robust, enduring understanding in multiple learning theories. This article describes the development and implementation of an assessment technique, termed a Measure of Linked Concepts, designed to inform instructors on students' understanding of linking content…

Linking Gestures: Cross-Cultural Variation during Instructional Analogies

ERIC Educational Resources Information Center

Richland, Lindsey Engle

2015-01-01

Deictic linking gestures, hand and arm motions that physically embody links being communicated between two or more objects in the shared communicative environment, are explored in a cross-cultural sample of mathematics instruction. Linking gestures are specifically examined here when they occur in the context of communicative analogies designed to…

Time Synchronization and Distribution Mechanisms for Space Networks

NASA Technical Reports Server (NTRS)

Woo, Simon S.; Gao, Jay L.; Clare, Loren P.; Mills, David L.

2011-01-01

This work discusses research on the problems of synchronizing and distributing time information between spacecraft based on the Network Time Protocol (NTP), where NTP is a standard time synchronization protocol widely used in the terrestrial network. The Proximity-1 Space Link Interleaved Time Synchronization (PITS) Protocol was designed and developed for synchronizing spacecraft that are in proximity where proximity is less than 100,000 km distant. A particular application is synchronization between a Mars orbiter and rover. Lunar scenarios as well as outer-planet deep space mother-ship-probe missions may also apply. Spacecraft with more accurate time information functions as a time-server, and the other spacecraft functions as a time-client. PITS can be easily integrated and adaptable to the CCSDS Proximity-1 Space Link Protocol with minor modifications. In particular, PITS can take advantage of the timestamping strategy that underlying link layer functionality provides for accurate time offset calculation. The PITS algorithm achieves time synchronization with eight consecutive space network time packet exchanges between two spacecraft. PITS can detect and avoid possible errors from receiving duplicate and out-of-order packets by comparing with the current state variables and timestamps. Further, PITS is able to detect error events and autonomously recover from unexpected events that can possibly occur during the time synchronization and distribution process. This capability achieves an additional level of protocol protection on top of CRC or Error Correction Codes. PITS is a lightweight and efficient protocol, eliminating the needs for explicit frame sequence number and long buffer storage. The PITS protocol is capable of providing time synchronization and distribution services for a more general domain where multiple entities need to achieve time synchronization using a single point-to-point link.

AQUATOX Frequently Asked Questions

EPA Pesticide Factsheets

Capabilities, Installation, Source Code, Example Study Files, Biotic State Variables, Initial Conditions, Loadings, Volume, Sediments, Parameters, Libraries, Ecotoxicology, Waterbodies, Link to Watershed Models, Output, Metals, Troubleshooting

Resting-state fMRI correlations: From link-wise unreliability to whole brain stability.

PubMed

Pannunzi, Mario; Hindriks, Rikkert; Bettinardi, Ruggero G; Wenger, Elisabeth; Lisofsky, Nina; Martensson, Johan; Butler, Oisin; Filevich, Elisa; Becker, Maxi; Lochstet, Martyna; Kühn, Simone; Deco, Gustavo

2017-08-15

The functional architecture of spontaneous BOLD fluctuations has been characterized in detail by numerous studies, demonstrating its potential relevance as a biomarker. However, the systematic investigation of its consistency is still in its infancy. Here, we analyze within- and between-subject variability and test-retest reliability of resting-state functional connectivity (FC) in a unique data set comprising multiple fMRI scans (42) from 5 subjects, and 50 single scans from 50 subjects. We adopt a statistical framework that enables us to identify different sources of variability in FC. We show that the low reliability of single links can be significantly improved by using multiple scans per subject. Moreover, in contrast to earlier studies, we show that spatial heterogeneity in FC reliability is not significant. Finally, we demonstrate that despite the low reliability of individual links, the information carried by the whole-brain FC matrix is robust and can be used as a functional fingerprint to identify individual subjects from the population. Copyright © 2017 Elsevier Inc. All rights reserved.

Entanglement-distillation attack on continuous-variable quantum key distribution in a turbulent atmospheric channel

NASA Astrophysics Data System (ADS)

Guo, Ying; Xie, Cailang; Liao, Qin; Zhao, Wei; Zeng, Guihua; Huang, Duan

2017-08-01

The survival of Gaussian quantum states in a turbulent atmospheric channel is of crucial importance in free-space continuous-variable (CV) quantum key distribution (QKD), in which the transmission coefficient will fluctuate in time, thus resulting in non-Gaussian quantum states. Different from quantum hacking of the imperfections of practical devices, here we propose a different type of attack by exploiting the security loopholes that occur in a real lossy channel. Under a turbulent atmospheric environment, the Gaussian states are inevitably afflicted by decoherence, which would cause a degradation of the transmitted entanglement. Therefore, an eavesdropper can perform an intercept-resend attack by applying an entanglement-distillation operation on the transmitted non-Gaussian mixed states, which allows the eavesdropper to bias the estimation of the parameters and renders the final keys shared between the legitimate parties insecure. Our proposal highlights the practical CV QKD vulnerabilities with free-space quantum channels, including the satellite-to-earth links, ground-to-ground links, and a link from moving objects to ground stations.

Meteorological analysis of symptom data for people with seasonal affective disorder.

PubMed

Sarran, Christophe; Albers, Casper; Sachon, Patrick; Meesters, Ybe

2017-11-01

It is thought that variation in natural light levels affect people with Seasonal Affective Disorder (SAD). Several meteorological factors related to luminance can be forecast but little is known about which factors are most indicative of worsening SAD symptoms. The aim of this meteorological analysis is to determine which factors are linked to SAD symptoms. The symptoms of 291 individuals with SAD in and near Groningen have been evaluated over the period 2003-2009. Meteorological factors linked to periods of low natural light (sunshine, global radiation, horizontal visibility, cloud cover and mist) and others (temperature, humidity and pressure) were obtained from weather observation stations. A Bayesian zero adjusted auto-correlated multilevel Poisson model was carried out to assess which variables influence the SAD symptom score BDI-II. The outcome of the study suggests that the variable sunshine duration, for both the current and previous week, and global radiation for the previous week, are significantly linked to SAD symptoms. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

[Analysis of dermatoglyphics of the digito-palmar and plantar complex in families].

PubMed

Letinić, D; Milicić, J

1998-01-01

This research was made in order to find out if there is an inherited component which determines the features of dermatoglyphics by transmitting inherited information from parents to children. The article shows the results of a research into 22 quantitative features of the digito-palmar complex, and 2 features of the plantar area in 400 persons. No significant differences were found in the parameters of the observed variables between fathers and sons, nor mothers and daughters. The differences were found, however, between fathers and daughters, and mothers and sons. The analysis of the correlation coefficients within the families showed that only the variables TRC and TPRC have polygenic hereditary model. The correlative analyses have shown close links between parents and children, the link between parents and sons being stronger than the link between parents and daughters. The research has not confirmed the thesis about greater overlap between mother and children, than between father and children, set forth by Knussmann in 1973.

Variable and complex food web structures revealed by exploring missing trophic links between birds and biofilm.

PubMed

Kuwae, Tomohiro; Miyoshi, Eiichi; Hosokawa, Shinya; Ichimi, Kazuhiko; Hosoya, Jun; Amano, Tatsuya; Moriya, Toshifumi; Kondoh, Michio; Ydenberg, Ronald C; Elner, Robert W

2012-04-01

Food webs are comprised of a network of trophic interactions and are essential to elucidating ecosystem processes and functions. However, the presence of unknown, but critical networks hampers understanding of complex and dynamic food webs in nature. Here, we empirically demonstrate a missing link, both critical and variable, by revealing that direct predator-prey relationships between shorebirds and biofilm are widespread and mediated by multiple ecological and evolutionary determinants. Food source mixing models and energy budget estimates indicate that the strength of the missing linkage is dependent on predator traits (body mass and foraging action rate) and the environment that determines food density. Morphological analyses, showing that smaller bodied species possess more developed feeding apparatus to consume biofilm, suggest that the linkage is also phylogenetically dependent and affords a compelling re-interpretation of niche differentiation. We contend that exploring missing links is a necessity for revealing true network structure and dynamics. © 2012 Blackwell Publishing Ltd/CNRS.

Mining gene link information for survival pathway hunting.

PubMed

Jing, Gao-Jian; Zhang, Zirui; Wang, Hong-Qiang; Zheng, Hong-Mei

2015-08-01

This study proposes a gene link-based method for survival time-related pathway hunting. In this method, the authors incorporate gene link information to estimate how a pathway is associated with cancer patient's survival time. Specifically, a gene link-based Cox proportional hazard model (Link-Cox) is established, in which two linked genes are considered together to represent a link variable and the association of the link with survival time is assessed using Cox proportional hazard model. On the basis of the Link-Cox model, the authors formulate a new statistic for measuring the association of a pathway with survival time of cancer patients, referred to as pathway survival score (PSS), by summarising survival significance over all the gene links in the pathway, and devise a permutation test to test the significance of an observed PSS. To evaluate the proposed method, the authors applied it to simulation data and two publicly available real-world gene expression data sets. Extensive comparisons with previous methods show the effectiveness and efficiency of the proposed method for survival pathway hunting.

Small Spacecraft Constellation Concept for Mars Atmospheric Radio Occultations

NASA Astrophysics Data System (ADS)

Asmar, S. W.; Mannucci, A. J.; Ao, C. O.; Kobayashi, M. M.; Lazio, J.; Marinan, A.; Massone, G.; McCandless, S. E.; Preston, R. A.; Seubert, J.; Williamson, W.

2017-12-01

First demonstrated in 1965 when Mariner IV flew by Mars and determined the salient features of its atmosphere, radio occultation experiments have been carried out on numerous planetary missions with great discoveries. These experiments utilize the now classic configuration of a signal from a single planetary spacecraft to Earth receiving stations, where the science data are acquired. The Earth science community advanced the technique to utilizing a constellation of spacecraft with the radio occultation links between the spacecraft, enabled by the infrastructure of the Global Positioning System. With the advent of small and less costly spacecraft, such as planetary CubeSats and other variations, such as the anticipated innovative Mars Cube One mission, crosslinks among small spacecraft can be used to study other planets in the near future. Advantages of this type of experiment include significantly greater geographical coverage, which could reach global coverage over a few weeks with a small number of spacecraft. Repeatability of the global coverage can lead to examining temperature-pressure profiles and ionospheric electron density profiles, on daily, seasonal, annual, or other time scales of interest. The higher signal-to-noise ratio for inter-satellite links, compared to a link to Earth, decreases the design demands on the instrumentation (smaller antennas and transmitters, etc.). After an actual Mars crosslink demonstration, this concept has been in development using Mars as a possible target. Scientific objectives, delivery methods, operational scenarios and end-to-end configuration have been documented. Science objectives include determining the state and variability of the lower Martian atmosphere, which has been an identified as a high priority objective by the Mars Exploration Program Analysis Group, particularly as it relates to entry, descent, and landing and ascent for future crewed and robotic missions. This paper will present the latest research on the proposed mission concept including the possible spatial and temporal coverage, resolution of observables, mission design and expected results.

Manipulation strategies for massive space payloads

NASA Technical Reports Server (NTRS)

Book, Wayne J.

1991-01-01

The industrial and environmental applications for robots with a relatively large workspace has increased significantly in the last few years. To accommodate the demands, the manipulator is usually designed with long, lightweight links that are inherently flexible. Ongoing research at Georgia Tech into the behavior and design of these flexible links is discussed.

Experimental verification of a model of a two-link flexible, lightweight manipulator. M.S. Thesis

NASA Technical Reports Server (NTRS)

Huggins, James David

1988-01-01

Experimental verification is presented for an assumed modes model of a large, two link, flexible manipulator design and constructed in the School of Mechanical Engineering at Georgia Institute of Technology. The structure was designed to have typical characteristics of a lightweight manipulator.

A link representation for gravity amplitudes

NASA Astrophysics Data System (ADS)

He, Song

2013-10-01

We derive a link representation for all tree amplitudes in supergravity, from a recent conjecture by Cachazo and Skinner. The new formula explicitly writes amplitudes as contour integrals over constrained link variables, with an integrand naturally expressed in terms of determinants, or equivalently tree diagrams. Important symmetries of the amplitude, such as supersymmetry, parity and (partial) permutation invariance, are kept manifest in the formulation. We also comment on rewriting the formula in a GL( k)-invariant manner, which may serve as a starting point for the generalization to possible Grassmannian contour integrals.

From one plot to many and from hillslopes to streams: Improving our understanding of catchment hydrology with a multi-scale experimental approach

NASA Astrophysics Data System (ADS)

Blume, Theresa; Weiler, Markus; Angermann, Lisa; Beiter, Daniel; Hassler, Sibylle; Kaplan, Nils; Lieder, Ernestine; Sprenger, Matthias

2017-04-01

Sustainable water resources management needs to be based on sound process understanding. This is especially true in a changing world, where boundary conditions change and models calibrated to the status quo are no longer helpful. There is a general agreement in the hydrologic community that we are in need of a better process understanding and that one of the most promising ways to achieve this is by using nested experimental designs that cover a range of scales. In the here presented study we argue that while we might be able to investigate a certain process at a plot or hillslope in detail, the real power of advancing our understanding lies in site intercomparison and if possible knowledge transfer and generalization. The experimental design of the CAOS observatory is based on sensor clusters measuring ground-, soil and stream water, sap flow and climate variables in 45 hydrological functional units which were chosen from a matrix of site characteristics (geology, land use, hillslope aspect, and topographic positions). This design allows for site intercomparisons that are based on more than one member per class and thus does not only characterize between class differences but also attempts to identify within-class variability. These distributed plot scale investigations offer a large amount of information on plot scale processes and their variability in space and time (e.g. water storage dynamics and patterns, vertical flow processes and vadose zone transit times, transpiration dynamics and patterns). However, if we want to improve our understanding of runoff generation (and thus also of nutrient and contaminant transport and export to the stream) we need to also understand how these plots link up within hillslopes and how and when these hillslopes are connected to the stream. And certainly, this is again most helpful if we do not focus on single sites but attempt experimental designs that aim at intercomparison and generalization. At the same time, the investigation of hillslope-stream connectivity is extremely challenging due to the fact that there is a high 4-dimensional variability of the involved processes and most of them are hidden from view in the subsurface. To tackle this challenge we employed a number of different field methods ranging from hillslope scale irrigation and flow-through experiments, to in depth analyses of near stream piezometer responses and stream reach tracer experiments, and then moving on to the mesoscale catchment with network wide investigations of spatial patterns of stream temperature and electric conductivity as well as of the expansion and shrinkage of the network itself. In this presentation we will provide an overview of the rationale, approach, experimental design and ongoing work, the challenges we encountered and a synthesis of exemplary results.

An Integrated Optimization Design Method Based on Surrogate Modeling Applied to Diverging Duct Design

NASA Astrophysics Data System (ADS)

Hanan, Lu; Qiushi, Li; Shaobin, Li

2016-12-01

This paper presents an integrated optimization design method in which uniform design, response surface methodology and genetic algorithm are used in combination. In detail, uniform design is used to select the experimental sampling points in the experimental domain and the system performance is evaluated by means of computational fluid dynamics to construct a database. After that, response surface methodology is employed to generate a surrogate mathematical model relating the optimization objective and the design variables. Subsequently, genetic algorithm is adopted and applied to the surrogate model to acquire the optimal solution in the case of satisfying some constraints. The method has been applied to the optimization design of an axisymmetric diverging duct, dealing with three design variables including one qualitative variable and two quantitative variables. The method of modeling and optimization design performs well in improving the duct aerodynamic performance and can be also applied to wider fields of mechanical design and seen as a useful tool for engineering designers, by reducing the design time and computation consumption.

Linking global climate and temperature variability to widespread amphibian declines putatively caused by disease.

PubMed

Rohr, Jason R; Raffel, Thomas R

2010-05-04

The role of global climate change in the decline of biodiversity and the emergence of infectious diseases remains controversial, and the effect of climatic variability, in particular, has largely been ignored. For instance, it was recently revealed that the proposed link between climate change and widespread amphibian declines, putatively caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd), was tenuous because it was based on a temporally confounded correlation. Here we provide temporally unconfounded evidence that global El Niño climatic events drive widespread amphibian losses in genus Atelopus via increased regional temperature variability, which can reduce amphibian defenses against pathogens. Of 26 climate variables tested, only factors associated with temperature variability could account for the spatiotemporal patterns of declines thought to be associated with Bd. Climatic predictors of declines became significant only after controlling for a pattern consistent with epidemic spread (by temporally detrending the data). This presumed spread accounted for 59% of the temporal variation in amphibian losses, whereas El Niño accounted for 59% of the remaining variation. Hence, we could account for 83% of the variation in declines with these two variables alone. Given that global climate change seems to increase temperature variability, extreme climatic events, and the strength of Central Pacific El Niño episodes, climate change might exacerbate worldwide enigmatic declines of amphibians, presumably by increasing susceptibility to disease. These results suggest that changes to temperature variability associated with climate change might be as significant to biodiversity losses and disease emergence as changes to mean temperature.

Identifying factors which enhance capacity to engage in clinical education among podiatry practitioners: an action research project.

PubMed

Abey, Sally; Lea, Susan; Callaghan, Lynne; Shaw, Steve; Cotton, Debbie

2015-01-01

Health profession students develop practical skills whilst integrating theory with practice in a real world environment as an important component of their training. Research in the area of practice placements has identified challenges and barriers to the delivery of effective placement learning. However, there has been little research in podiatry and the question of which factors impact upon clinical educators' capacity to engage with the role remains an under-researched area. This paper presents the second phase of an action research project designed to determine the factors that impact upon clinical educators' capacity to engage with the mentorship role. An online survey was developed and podiatry clinical educators recruited through National Health Service (NHS) Trusts. The survey included socio-demographic items, and questions relating to the factors identified as possible variables influencing clinical educator capacity; the latter was assessed using the 'Clinical Educator Capacity to Engage' scale (CECE). Descriptive statistics were used to explore demographic data whilst the relationship between the CECE and socio-demographic factors were examined using inferential statistics in relation to academic profile, career profile and organisation of the placement. The survey response rate was 42 % (n = 66). Multiple linear regression identified four independent variables which explain a significant proportion of the variability of the dependent variable, 'capacity to engage with clinical education', with an adjusted R2 of 0.428. The four variables were: protected mentorship time, clinical educator relationship with university, sign-off responsibility, and volunteer status. The identification of factors that impact upon clinical educators' capacity to engage in mentoring of students has relevance for strategic planning and policy-making with the emphasis upon capacity-building at an individual level, so that the key attitudes and characteristics that are linked with good clinical supervision are preserved.

Transmitters and receivers in free space optical communications for Deep Space links

NASA Technical Reports Server (NTRS)

Beebe, J.

2003-01-01

Two of the many research areas integral making a Mars-Earth optical communication link a reality are optical antenna design and laser transmitter design. This paper addresses areas of both of these by exploring a mode-matched design for a cavity-dumped communications laser, and by reporting on the initial stages of the analysis of an existing 100 inch telescope for use as an optical communications receiver.

Chinese Preservice Teachers’ Professional Identity Links with Education Program Performance: The Roles of Task Value Belief and Learning Motivations

PubMed Central

Zhang, Yan; Hawk, Skyler T.; Zhang, Xiaohui; Zhao, Hongyu

2016-01-01

Professional identity is a key issue spanning the entirety of teachers’ career development. Despite the abundance of existing research examining professional identity, its link with occupation-related behavior at the primary career stage (i.e., GPA in preservice education) and the potential process that underlies this association is still not fully understood. This study explored the professional identity of Chinese preservice teachers, and its links with task value belief, intrinsic learning motivation, extrinsic learning motivation, and performance in the education program. Grade-point average (GPA) of courses (both subject and pedagogy courses) was examined as an indicator of performance, and questionnaires were used to measure the remaining variables. Data from 606 preservice teachers in the first 3 years of a teacher-training program indicated that: (1) variables in this research were all significantly correlated with each other, except the correlation between intrinsic learning motivation and program performance; (2) professional identity was positively linked to task value belief, intrinsic and extrinsic learning motivations, and program performance in a structural equation model (SEM); (3) task value belief was positively linked to intrinsic and extrinsic learning motivation; (4) higher extrinsic (but not intrinsic) learning motivation was associated with increased program performance; and (5) task value belief and extrinsic learning motivation were significant mediators in the model. PMID:27199810

Chinese Preservice Teachers' Professional Identity Links with Education Program Performance: The Roles of Task Value Belief and Learning Motivations.

PubMed

Zhang, Yan; Hawk, Skyler T; Zhang, Xiaohui; Zhao, Hongyu

2016-01-01

Professional identity is a key issue spanning the entirety of teachers' career development. Despite the abundance of existing research examining professional identity, its link with occupation-related behavior at the primary career stage (i.e., GPA in preservice education) and the potential process that underlies this association is still not fully understood. This study explored the professional identity of Chinese preservice teachers, and its links with task value belief, intrinsic learning motivation, extrinsic learning motivation, and performance in the education program. Grade-point average (GPA) of courses (both subject and pedagogy courses) was examined as an indicator of performance, and questionnaires were used to measure the remaining variables. Data from 606 preservice teachers in the first 3 years of a teacher-training program indicated that: (1) variables in this research were all significantly correlated with each other, except the correlation between intrinsic learning motivation and program performance; (2) professional identity was positively linked to task value belief, intrinsic and extrinsic learning motivations, and program performance in a structural equation model (SEM); (3) task value belief was positively linked to intrinsic and extrinsic learning motivation; (4) higher extrinsic (but not intrinsic) learning motivation was associated with increased program performance; and (5) task value belief and extrinsic learning motivation were significant mediators in the model.

An Investigation of Flight Deck Data Link in the Terminal Area

NASA Technical Reports Server (NTRS)

Martin, Lynne; Lozito, Sandra; Kaneshige, John; Dulchinos, Vicki; Sharma, Shivanjli

2013-01-01

The Next Generation Air Transportation System (NextGen) and Europe's Single European Sky ATM Research (SESAR) concepts require an increased use of trajectory-based operations, including extensive strategic air traffic control clearances. The clearances are lengthy and complex, which necessitate data link communications to allow for message permanence and integration into the autoflight systems (i.e., autoload capability). This paper examines the use of flight deck data link communications for strategic and tactical clearance usage in the terminal area. A human-in-the-loop simulation was conducted using a high-fidelity flight deck simulator, with ten commercial flight crews as participants. Data were collected from six flight scenarios in the San Francisco terminal airspace. The variables of interest were ATC message modality (voice v. data link), temporal quality of the message (tactical v. strategic) and message length. Dependent variables were message response times, communication clarifications, communication-related errors, and pilot workload. Response time results were longer in data link compared to voice, a finding that has been consistently revealed in a number of other simulations [1]. In addition, strategic clearances and longer messages resulted in a greater number of clarifications and errors, suggesting an increase in uncertainty of message interpretation for the flight crews when compared to tactical clearances. The implications for strategic and compound clearance usage in NextGen and SESAR are discussed