bluuebunny/crossref_metadata_2025 huggingface dataset:
Mutation of alpha‐tubulin genes in trifluralin‐resistant water foxtail (Alopecurus aequalis)
Authors: Hashim Saima , Jan Asad , Sunohara Yukari , Hachinohe Mayumi , Ohdan Hideki , Matsumoto Hiroshi
Published: October 2011

BACKGROUND: Trifluralin‐resistant biotypes of water foxtail (Alopecurus aequalis) have been identified in wheat fields from northern Kyushu, Japan. Water foxtail is a winter‐annual grassy weed, causing substantial crop losses. This study reports on mutation in α‐tubulin (TUA) genes from water foxtail, the site of action of trifluralin.

RESULTS: Two trifluralin‐sensitive (S) Chikugo and Ukiha biotypes and four trifluralin‐resistant (R) Asakura‐1, Asakura‐2, Tamana and Tosu biotypes of water foxtail were used for herbicide resistance analysis. R biotypes showed 5.7–30.7‐fold trifluralin resistance compared with the S biotypes. No differences in the uptake and translocation of 14C‐trifluralin were observed between Chikugo (S) biotype and Asakura‐1 (R) biotype. Most of the 14C detected in the plant material was in the root tissue, and no substantial increases were noted in shoot tissues. Comparative TUA sequence analysis revealed two independent single amino acid changes: change of Val into Phe at position 202 in TUA1 and change of Leu into Met at position 125 in TUA3 in Asakura‐1 biotype. In the Tamana (R) biotype, two amino acid changes of Leu to Phe at position 136 and Val to Phe at position 202 were observed in the predicted amino acid sequence of TUA1, compared with Chikugo (S) biotype.

CONCLUSION: The results provide preliminary molecular explanation for the resistance of water foxtail to trifluralin, a phenomenon that has arisen as a result of repeated exposure to this class of herbicide. This is the first report of α‐tubulin mutation in water foxtail and for any Alopecurus species reported in the literature. Copyright © 2011 Society of Chemical Industry
Improving satellite services with cooperative communications
Authors: Paillassa Beatrice , Escrig Benoît , Dhaou Riadh , Boucheret Marie‐Laure , Bes Caroline
Published: October 2011

This paper proposes new transmission schemes for the delivery of satellite services. In the proposed scenarios, mobile terminals are allowed to forward the signal received from the satellite. This scheme provides spatial diversity just like MIMO transmission schemes. Moreover, the coverage area is extended because masked terminals have an additional opportunity to get the service from neighboring terminals. We use the paradigm of cooperative communications to compare the advantages and limitations of several scenarios in hybrid terrestrial/satellite systems. In particular, we study the following basic transmission scheme: in a first time slot, the satellite sends its signal and, in a second time slot, mobile terrestrial terminals are relaying the satellite signal. An analysis framework is proposed and applied to this cooperation scenario at the destination terminal. The framework is modeling the cooperation process and clearly separates the control part from the data user part. The paper outlines the importance of the control part by evaluating the relay selection policy on a basic hybrid satellite/ad hoc system. Copyright © 2011 John Wiley & Sons, Ltd.
Secure and efficient dynamic program update in wireless sensor networks
Authors: He Daojing , Chan Sammy , Chen Chun , Bu Jiajun
Published: October 2011

Dynamic program update protocols provide a convenient way to reprogram sensor nodes after deployment. However, designing a secure program update protocol for wireless sensor networks is a difficult task because wireless networks are susceptible to attacks and nodes have limited resources. Recently, two secure program update protocols using orthogonality principle have been found to be vulnerable to two impersonation attacks, although these attacks are rather restrictive. This paper reports one new attack that is more general and makes the program update protocols even more vulnerable. With this attack, an attacker can easily impersonate the base station to install his/her preferred program on sensor nodes and then obtain control over the network. As a remedy, two simple countermeasures are suggested to defend against all these attacks. Finally, the security properties of the two proposed solutions are formally validated by a model checking tool. Copyright © 2011 John Wiley & Sons, Ltd.
Identity management‐based social trust model for mediating information sharing and privacy enhancement
Authors: Kim Mucheol , Seo Jiwan , Noh Sanghyun , Han Sangyong
Published: October 2011

As interest in social network studies has grown bigger along with the development of the Web, social network trust management and applications have come into the spotlight. The increasing interest in social network services that are open systems has motivated the need for a reliable trust model that enables practical information sharing and information protection. In this paper, we propose an identity management‐based social trust model for solving a sparsity problem and an information leakage. The proposed trust model contributes to increasing the opportunities for information sharing. In addition, the creation and use of identity groups with a clustering approach and partial identities in the proposed approach effectively address security and privacy risks in social networks. In experiments, the performance of the proposed approach is evaluated using precision–recall and F‐measures. Copyright © 2011 John Wiley & Sons, Ltd.
The design of conditional access mechanism for ubiquitous video on demand services
Authors: Chen Yu‐Yi , Huang Der‐Chen , Tsai Meng‐Lin
Published: October 2011

Conditional access (CA) is the access control mechanism used for pay TV or video on demand (VoD) service. It should control the transmitted programs that can be accessed by the authorized subscribers. Thus, the subscribers can be charged, and any illegal access can be prevented. Wireless mesh networks (WMNs) are an enabling technology for ubiquitous access to the Internet and a low‐cost alternative to extend the Internet as compared with other wireless networks. This paper proposes a CA mechanism for ubiquitous VoD services based on WMNs. The scheme guarantees mutual authentication, privacy, and anonymity and also resists spoofed service provider attack, spoofed user attack, replay attack, message modification attack, illegal content distribution, and service repudiation. Copyright © 2011 John Wiley & Sons, Ltd.
A Bayesian approach to risk‐adjusted outcome monitoring in healthcare
Authors: Zeng L. , Zhou S.
Published: October 2011

Clinical outcomes are commonly monitored in healthcare practices to detect changes in care providers' performance. One key challenge in outcome monitoring is the need of adjustment for patient base‐line risks. Various control charting methods have been developed to conduct risk‐adjusted outcome monitoring, but they all rely on the availability of a large number of historical data. We propose a Bayesian approach to this type of monitoring for cases where historical data are not available. In our approach, detection of change is formulated as a model‐selection problem and solved using a popular Bayesian tool for variable selection, the Bayes factor. Issues in decision‐making about whether there is a change point in the observed patient outcomes are addressed, including specification of priors and computation of Bayes factors. This approach is applied to a real data set on cardiac surgeries, and its performance under different parameter scenarios is studied through simulations. Copyright © 2011 John Wiley & Sons, Ltd.
Reweighting estimators for Cox regression with missing covariate data: Analysis of insulin resistance and risk of stroke in the Northern Manhattan Study
Authors: Xu Qiang , Paik Myunghee Cho , Rundek Tatjana , Elkind Mitchell S. V. , Sacco Ralph L.
Published: October 2011

Incomplete covariates often obscure analysis results from a Cox regression. In an analysis of the Northern Manhattan Study (NOMAS) to determine the influence of insulin resistance on the incidence of stroke in nondiabetic individuals, insulin level is unknown for 34.1% of the subjects. The available data suggest that the missingness mechanism depends on outcome variables, which may generate biases in estimating the parameters of interest if only using the complete observations. This article aimed to introduce practical strategies to analyze the NOMAS data and present sensitivity analyses by using the reweighting method in standard statistical packages. When the data set structure is in counting process style, the reweighting estimates can be obtained by built‐in procedures with variance estimated by the jackknife method. Simulation results indicate that the jackknife variance estimate provides reasonable coverage probability in moderate sample sizes. We subsequently conducted sensitivity analyses for the NOMAS data, showing that the risk estimates are robust to a variety of missingness mechanisms. At the end of this article, we present the core SAS and R programs used in the analysis. Copyright © 2011 John Wiley & Sons, Ltd.
Design evaluation and optimisation in crossover pharmacokinetic studies analysed by nonlinear mixed effects models
Authors: Nguyen Thu Thuy , Bazzoli Caroline , Mentré France
Published: October 2011

Bioequivalence or interaction trials are commonly studied in crossover design and can be analysed by nonlinear mixed effects models as an alternative to noncompartmental approach. We propose an extension of the population Fisher information matrix in nonlinear mixed effects models to design crossover pharmacokinetic trials, using a linearisation of the model around the random effect expectation, including within‐subject variability and discrete covariates fixed or changing between periods. We use the expected standard errors of treatment effect to compute the power for the Wald test of comparison or equivalence and the number of subjects needed for a given power. We perform various simulations mimicking crossover two‐period trials to show the relevance of these developments. We then apply these developments to design a crossover pharmacokinetic study of amoxicillin in piglets and implement them in the new version 3.2 of therfunction PFIM. Copyright © 2011 John Wiley & Sons, Ltd.
Effect of steady and transient wind shear on the wake structure and performance of a horizontal axis wind turbine rotor
Authors: Sezer‐Uzol Nilay , Uzol Oguz
Published: October 2011

This paper presents an investigation of the effect of steady and transient free‐stream wind shear on the wake structure and performance characteristics of a horizontal axis wind turbine rotor. A new three‐dimensional unsteady vortex‐panel method potential flow solver based on a free‐vortex wake methodology, AeroSIM+, is used for this purpose. The code is validated using the experimental data from the National Renewable Energy Laboratory Unsteady Aerodynamics Experiments. The effects of vortex core model, core size, expansion, and filament stretching on torque and thrust predictions are investigated. Three‐different wind shear cases, i.e., uniform inflow (no wind shear), steady vertical wind shear that uses a power law velocity profile (Normal Wind Profile, NWP) and transient Extreme Wind Shear (EWS), are investigated. The results show that the existence of wind shear can create a very complex wake structure with substantial asymmetries, streamwise vorticity generation, and non‐periodicities downstream of the turbine rotor. In addition, the blades are subjected to asymmetrical surface pressure variations that in turn result in high amplitude fluctuations in power and thrust levels generated by the turbine. Copyright © 2011 John Wiley & Sons, Ltd.
The mechanical generation of fault trees for reactive systems via retrenchment II: clocked and feedback circuits
Authors: Banach Richard , Bozzano Marco
Published: October 2011

The retrenchment approach to the mechanical construction of fault trees, introduced in the first paper for combinational logic circuits, is extended to handle clocked circuits and then feedback circuits. The temporal behaviour of clocked circuits is captured using their causal relations, and the potentially unbounded behaviour of cyclic circuits is decomposed into an iteration over their acyclic counterparts. The repercussions of all this for the theory of retrenchment are elaborated. For clocked circuits, the techniques we present allow glitches and other transient errors to be properly described. For feedback circuits, the plethora of behaviours that can occur, give rise to infinitary fault trees of an appropriate kind. All this paves the way for automated fault tree generation for reactive systems.
Measuring Religiousness among Older African Americans: Exploring Race-of-Interviewer Effects
Authors: Ellison Christopher G. , McFarland Michael J. , Krause Neal
Published: October 2011

In recent years a number of studies have explored possible sources of nonrandom error and response bias in survey data on religion. Building on a longstanding body of work in the social sciences, we examine a neglected issue in this domain: the potential for race-of-interviewer effects, specifically in African Americans’ self-reports of various dimensions of religiousness. After outlining two competing perspectives on this issue—which we term racial deference and racial solidarity—we test relevant hypotheses using data from the African American oversample of a nationwide study of older adults. Results indicate that older blacks tend to report higher levels of non-organizational religious practices and subjective religiousness when interviewed by whites. A number of implications and promising directions for future research are discussed.
Black Church Sponsorship of Economic Programs: A Test of Survival and Liberation Strategies
Authors: Barnes Sandra L.
Published: October 2011

The Black Church has a long history of sponsoring programs in response to economic challenges in the African American community. Yet current double digit poverty and unemployment rates among African Americans suggest the need to examine their current efforts to combat economic problems. This study, informed by the “survival versus liberation” thesis, examines sponsorship of cash programs, employment programs, and credit unions for a national sample of 1,863 Black churches across seven denominations. Results show the tendency for Black churches to sponsor economic programs to meet more short-term needs rather than address systemic issues. Moreover, findings from logistic regression modeling suggest limited denominational effects, but a positive relationship between churches that espouse a more liberative stance and economic program sponsorship—particularly programs associated with more long-term benefits. Furthermore, Black churches that offer more educational and contemplative religious programs and that have the requisite human resources and organizational structure appear best positioned to offer these economic programs. Results provide important insights into the Black Church economic ethic.
Social Relationships in the Church during Late Life: Assessing Differences between African Americans, Whites, and Mexican Americans
Authors: Krause Neal , Bastida Elena
Published: October 2011

The purpose of this study is to see if there are differences in the social relationships that older African Americans, older whites, and older Mexican Americans form with the people where they worship. Data from two large surveys are pooled to see if race differences emerge in eleven different measures of church-based social relationships. These measures assess social relationships with rank-and-file church members as well as social relationships with members of the clergy. The findings reveal that older African Americans tend to have more well-developed social relationships in the church than either older whites or older Mexican Americans. This is true with respect to relationships with fellow church members as well as relationships with the clergy. In contrast, relatively few differences emerged between older Americans of European descent and older Mexican Americans. However, when differences emerged in the data, older whites tend to score higher on the support measures than older Mexican Americans.
The Perceived Prayers of Others, Stress, and Change in Depressive Symptoms over Time
Authors: Krause Neal
Published: October 2011

The purpose of this study was to see if believing that others are praying for them reduces the noxious effect of living in a rundown neighborhood on change in depressive symptoms among older people. Findings from a longitudinal nationwide survey of older adults reveal that the deleterious effect of living in a dilapidated neighborhood on depressive symptoms is significantly reduced for older individuals who believe others often pray for them. Further analyses suggest that the stress-buffering properties of beliefs about being prayed for by others remain virtually unchanged after emotional support from family members and close friends is taken into account. The findings have potentially important implications for studying church-based prayer groups as well as assessing the ways in which individuals might support each other during difficult times.
Risk assessment and receiver operating characteristic curves
Authors: Szmukler G. , Everitt B. , Leese M.
Published: October 2011

Risk assessment is now regarded as a necessary competence in psychiatry. The area under the curve (AUC) statistic of the receiver operating characteristic curve is increasingly offered as the main evidence for accuracy of risk assessment instruments. But, even a highly statistically significant AUC is of limited value in clinical practice.
Asymptotic Improvements to the Lower Bound of Certain Bipartite Turán Numbers
Authors: BALL SIMEON , PEPE VALENTINA
Published: October 2011

We show that there are graphs with n vertices containing no K5,5 which have about n7/4 edges, thus proving that ex(n, K5,5) ≥ (1 + o(1))n7/4. This bound gives an asymptotic improvement to the known lower bounds on ex(n, Kt, s) for t = 5 when 5 ≤ s ≤ 12, and t = 6 when 6 ≤ s ≤ 8.
Fully polarimetric scattering from random rough layers under the geometric optics approximation: Geoscience applications
Authors: Pinel N. , Johnson J. T. , Bourlier C.
Published: October 2011

Predictions of the geometric optics approximation for scattering from two rough interfaces that separate three homogeneous media (the “GO‐layer” model) are examined for their implications for radar remote sensing. A previous formulation of the rough layer normalized radar cross section (NRCS) is also extended to allow calculation of the polarimetric covariance of the scattered field. Example results are presented for both bistatic and monostatic configurations, and show the influence of subsurface interfaces on scattered field properties. In particular, complete hemispherical bistatic patterns of both NRCS and polarimetric correlations are illustrated to provide insight into the impact of subsurface layers on these quantities. It is shown that the observability of sub‐surface contributions in general is larger for geometries where upper interface returns are smaller (i.e. angles outside the quasi‐specular return of the upper interface), and it is also shown that significant decorrelations between polarizations can occur in the presence of sub‐surface layers. Variations of field properties with medium physical parameters (inner layer thickness and relative permittivity, upper and lower surface RMS slopes, radar frequency) are also shown. A problem that has received extensive previous interest (subsurface sensing in arid regions having an upper sand layer over a granite bedrock) is re‐examined for remote sensing at higher frequencies, and it is shown that subsurface contributions can impact backscattered NRCS returns even up to X‐band frequencies. The examples presented can be utilized to assess the potential detectability of sub‐surface layers for both monostatic radar observations and near specular observations (as in GNSS reflection observations of land surfaces).
Congress hears from astronauts about human spaceflight
Authors: Showstack Randy
Published: October 2011

NASA's 15 September announcement of a new Space Launch System (SLS) design, which includes a heavy lift rocket in combination with the Orion Multi‐Purpose Crew Vehicle (MPCV) already under development, generally was favorably received at a 22 September congressional hearing on NASA and human spaceflight held by the U.S. House of Representatives' Committee on Science, Space, and Technology. However, witnesses, including Apollo 11 commander Neil Armstrong, said they remain concerned about America's manned access to space, the nation's leadership in manned space exploration, and what they said is the lack of a clear direction for NASA. Armstrong said the proposal for the new heavy lift vehicle “appears to meet the intent” of a congressional mandate in the NASA Authorization Act of 2010, but he also said that the past year has been “frustrating” to NASA observers trying to understand the agency's plans and progress in the area of human space exploration. “The NASA leadership enthusiastically assured the American people that the agency was embarking on an exciting new age of discovery in the cosmos. But the realities of the termination of the shuttle program, the cancellation of existing rocket launcher and spacecraft programs, the layoffs of thousands of aerospace workers, and the outlook for American space activity throughout the next decade were difficult to reconcile with the agency assertions,” Armstrong said.
Honors
Authors: Anonymous
Published: October 2011

Three AGU members are among the 10 recipients of this year's Heinz Awards, announced on 13 September by Teresa Heinz and the Heinz Family Foundation. Richard Alley, Evan Pugh Professor of Geosciences at Pennsylvania State University, in University Park, was recognized for his polar ice discoveries that showed that abrupt climate change is possible and for engaging his students, policy makers, and the public.Joan Kleypas, a marine ecologist and geologist at the National Atmospheric and Oceanic Administration's National Center for Atmospheric Research, was honored for conducting seminal research on how changes in temperature and in seawater chemistry and acidity have affected coral reefs and for identifying ways to bolster coral reef health. Nancy Rabalais, executive director of the Louisiana Universities Marine Consortium, in Chauvin, was cited for her pioneering research of severe oxygen depletion in the Gulf of Mexico and her commitment to reducing water pollution through education and public policy. The awards program “recognizes individuals creating and implementing workable solutions to the problems the world faces through invention, research, and education while inspiring the next generation of modern thinkers,” according to the foundation. Each recipient receives an unrestricted cash prize of $100,000.
Congressional geohazards showcase presented by NSF and AGU
Authors: Uhlenbrock Kristan
Published: October 2011

On Wednesday, 7 September 2011, two weeks after the magnitude 5.8 earthquake in Mineral, Va., and a week after Hurricane Irene struck the U.S. East Coast, AGU cosponsored a showcase of National Science Foundation (NSF)—funded hazards research in recognition of National Preparedness Month. This annual event highlights NSF—funded hazards research from all over the United States, with more than 30 exhibitors demonstrating the latest research and technology on hurricanes, earthquakes, tornadoes, volcanoes, tsunamis, and oil spills, as well as emergency and social responses to these events. The event took place at the Hart Senate Office Building, where many members of Congress and their staff could attend and discuss the importance of hazards research with the researchers and NSF staff. Sen. Bill Nelson (D‐Fla.) kicked off with a panel of speakers, which included remarks by Mary Voytek, a member of the AGU Board of Directors, and Subra Suresh, director of NSF. Expert presentations were also given on hazard prediction, human safety, and social response. Following the event, Senate Majority Leader Harry Reid (D‐Nev.) hosted a small event to meet directly with a few of the exhibitors to discuss the importance of investment in scientific research and development.
Thermal expansion not a major source of sea level rise
Authors: Schultz Colin
Published: October 2011

With the power to drown low‐lying nations, destroy infrastructure, and seriously affect sensitive coastal ecosystems, sea level rise may be one of the most readily apparent consequences of global warming that is already under way. The sources of, and dynamics driving, the rising waters, however, are not so clear. Melting land‐locked glaciers, shrinking ice sheets over Greenland and Antarctica, and the ocean's thermal expansion will all play a part, but the expected contribution from each of these sources is still up for debate. Previous studies have suggested that thermal expansion driven by rising sea surface temperatures will account for up to 70% of sea level rise in the near future, but research by McKay et al. suggests this may be a drastic overestimate.
Potential for resumption of East Pacific sea level rise after 30‐year hiatus
Authors: Schultz Colin
Published: October 2011

Over the course of the past century the global rate of sea level rise has increased threefold, jumping from 1 millimeter per year in the early 1900s to 3 millimeters per year in the late twentieth century. This seemingly small increase in the global average can have serious consequences when regional influences come into play, as can be the case for low‐lying islands and coastal regions with shallow shores. One locale has so far managed to escape any impact from the global trend, but that security may soon be coming to an end. Since the 1980s the sea level height off the North American West Coast has barely budged. This finding, recorded in both satellite altimetry and tidal gauge records, suggests to Bromirski et al. that something has been suppressing the local rate of sea level rise.
Observations of abyssal flow and mixing
Authors: Balcerak Ernie
Published: October 2011

Scientists once thought the abyssal ocean, near the ocean bottom, was nearly stagnant, but recent observations show it is quite dynamic and that abyssal mixing plays an important role in the general circulation. Contributing to understanding of abyssal flow,Alford et al. report measurements of temperature and velocity in the abyssal ocean from two moorings near Hawaii. They found three major cold events in their 2.5‐year record, indicating that mixing events are strongly intermittent. They focus in detail on one unusual cold event that appeared in two pulses spaced about 2 weeks apart in September and October 2010. The event included an anomalously low temperature about 0.15°C below normal temperatures that extended more than 500 meters above the ocean bottom as well as vigorous turbulent flows. (Geophysical Research Letters, doi:10.1029/2011GL048075, 2011)
The Interface of Language Proficiency and Identity: A Profile Analysis of Bilingual Adolescents and Their Writing
Authors: Danzak Robin L.
Published: October 2011

Purpose

The purpose of this study was to explore how adolescent English language learners' (ELLs') language and literacy experiences impacted their identities as bilingual writers.

Method

Six students were randomly selected from a group of 20 Spanish-speaking ELLs, ages 11–14, who participated in a larger, mixed-methods study on bilingual writing (see Danzak, 2011). The participants produced 10 written journal entries in their language of choice (English, Spanish, or both) and were interviewed. Qualitative analyses were applied to the participants' writing and interviews, both individually and cross-case. Findings were integrated to some extent with the outcomes of quantitative measures applied to the students' writing.

Results

Three patterns emerged: ethnic differences, language discrimination, and language preference. Also, the students' self-identification as monolingual or bilingual was reflected in their attitudes toward language learning and their outcomes on writing measures. Three portraits of emerging bilingual writers are discussed: struggling emerging, dominant emerging, and balanced emerging. Language and literacy learning strategies are recommended for each.

Conclusions

Qualitative profiles of adolescent ELLs offer an understanding of students' experiences and identities that augments information provided by quantitative writing measures. Additionally, a mixed-methods profile analysis may aid in the identification of adolescent ELLs who may be struggling with undiagnosed language learning disabilities.
Grammatical Morphology in School-Age Children With and Without Language Impairment: A Discriminant Function Analysis
Authors: Moyle Maura Jones , Karasinski Courtney , Weismer Susan Ellis , Gorman Brenda K.
Published: October 2011

Purpose

The purpose of this study was to test Bedore and Leonard’s (1998) proposal that a verb morpheme composite may hold promise as a clinical marker for specific language impairment (SLI) in English speakers and serve as an accurate basis for the classification of children with and without SLI beyond the preschool level.

Method

The language transcripts of 50 school-age children with SLI (
M
age
= 7;9 [years;months]) and 50 age-matched typically developing peers (
M
age
= 7;9) were analyzed. Following the Bedore and Leonard (1998) procedure, 3 variables were measured: a finite verb morpheme composite, a noun morpheme composite, and mean length of utterance in morphemes (MLU
m
).

Results

Overall findings indicated that neither grammatical morpheme composite alone adequately discriminated the groups at this developmental level. However, combining the verb and noun grammatical morpheme composite measures with MLU
m
resulted in good discriminant accuracy in classifying subgroups of the youngest children with and without SLI in the school-age sample.

Conclusion

Verb morphology alone is not a useful clinical marker of SLI in school-age children. Potential explanations for these findings and ideas for future research are discussed.
Increasing the Odds: Applying Emergentist Theory in Language Intervention
Authors: Poll Gerard H.
Published: October 2011

Purpose

This review introduces emergentism, which is a leading theory of language development that states that language ability is the product of interactions between the child’s language environment and his or her learning capabilities. The review suggests ways in which emergentism provides a theoretical rationale for interventions that are designed to address developmental language delays in young children.

Method

A review of selected literature on emergentist theory and research is presented, with a focus on the acquisition of early morphology and syntax. A significant method for developing and testing emergentist theory, connectionist modeling, is described. Key themes from both connectionist and behavioral studies are summarized and applied with specific examples to language intervention techniques. A case study is presented to integrate elements of emergentism with language intervention.

Conclusions

Evaluating the theoretical foundation for language interventions is an important step in evidence-based practice. This article introduces three themes in the emergentist literature that have implications for language intervention: (a) sufficiency of language input, (b) active engagement of the child with the input, and (c) factors that increase the odds for correctly mapping language form to meaning. Evidence supporting the importance of these factors in effective language intervention is presented, along with limitations in that evidence.
Classification Accuracy of Brief Parent Report Measures of Language Development in Spanish-Speaking Toddlers
Authors: Guiberson Mark , Rodríguez Barbara L. , Dale Philip S.
Published: October 2011

Purpose

The purpose of the current study was to examine the concurrent validity and classification accuracy of 3 parent report measures of language development in Spanish-speaking toddlers.

Method

Forty-five Spanish-speaking parents and their 2-year-old children participated. Twenty-three children had expressive language delays (ELDs) as determined through multiple sources of information, and 22 had typical language development (TD). Parents completed the Spanish version of the Ages and Stages Questionnaire (Spanish ASQ; Squires, Potter, & Bricker, 1999) and the short-form of the Inventarios del Desarrollo de Habilidades Comunicativas Palabras y Enunciados (INV–II; Jackson-Maldonado, Bates, & Thal, 1992; Jackson-Maldonado et al., 2003), which is the Spanish version of the MacArthur-Bates Communicative Development Inventories Words and Sentences form, and reported children’s 3 longest utterances (M3L–W). Children were administered the Preschool Language Scale, Fourth Edition, Spanish Edition (SPLS–4; Zimmerman, Steiner, & Pond, 2002) at early childhood centers.

Results

All 3 parent report measures were significantly correlated with the SPLS–4, establishing their concurrent validity. Children with ELDs scored significantly lower than TD children on all 3 parent report measures. The Spanish ASQ demonstrated less than desirable levels of sensitivity and specificity; both the short-form INV–II and M3L–W measures demonstrated favorable sensitivity and specificity. Of these measures, M3L–W demonstrated the strongest classification accuracy qualities, including sensitivity, negative predictive value, and area under the receiver operating characteristics curve.

Conclusion

The short-form INV–II and M3L–W demonstrated highly satisfactory classification accuracy of ELDs, but M3L–W demonstrated slightly stronger accuracy. These results indicate that these measures may be useful in screening for ELDs in Spanish-speaking toddlers.
Peer Victimization Among Students With Specific Language Impairment, Attention-Deficit/Hyperactivity Disorder, and Typical Development
Authors: Redmond Sean M.
Published: October 2011

Purpose

The potential contributions of behavioral and verbal liabilities to social risk were examined by comparing peer victimization levels in children with specific language impairment (SLI) to those in children with attention-deficit/hyperactivity disorder (ADHD) and typically developing (TD) children.

Method

Sixty children (age range: 7–8 years) participated in the study. Standardized verbal measures and parent ratings of behavioral difficulties were combined with children’s self-reports of their school and peer environments to examine the risk for negative peer experiences associated with clinical status.

Results

Clinical status was associated with elevated levels of victimization, especially for participants with SLI. A potential buffering effect for number of close friendships was found for participants with ADHD and TD participants, but not for participants with SLI. Peer victimization was associated with elevated levels of hyperactivity and stronger narrative skills for participants with SLI.

Conclusion

These results highlight the importance of peer victimization in the social adjustment of students with developmental language disorders.
What Is Orthographic Knowledge?
Authors: Apel Kenn
Published: October 2011

Purpose

Orthographic knowledge refers to the information that is stored in memory that tells us how to represent spoken language in written form. Unfortunately, terms used to talk about orthographic knowledge and the two individual components that contribute to it have varied widely in the literature. Thus, consensus on the term, its meaning, and the tasks used to assess orthographic knowledge is needed.

Method

In this tutorial, the problems and inconsistencies in terms and tasks used to define and measure orthographic knowledge are reviewed, and suggestions for using specific terms are offered. Additionally, orthographic knowledge development, considerations of its role in literacy development, and its independence from other factors that contribute to literacy development are discussed. Finally, ideas for overcoming current obstacles in discussions of orthographic knowledge and suggestions for future research endeavors are offered.

Conclusion

With consensus on what orthographic knowledge is and how it should be measured, practitioners should be better prepared for assessing orthographic knowledge and implementing instructional practices accordingly.
Two-dimensional magnetohydrodynamic simulations of poloidal flows in tokamaks and MHD pedestal
Authors: Guazzotto L. , Betti R.
Published: October 2011

Poloidal rotation is routinely observed in present-day tokamak experiments, in particular near the plasma edge and in the high-confinement mode of operation. According to the magnetohydrodynamic (MHD) equilibrium theory [R. Betti and J. P. Freidberg, Phys. Plasmas 7, 2439 (2000)], radial discontinuities form when the poloidal velocity exceeds the poloidal sound speed (or rather, more correctly, the poloidal magneto-slow speed). Two-dimensional compressible magnetohydrodynamic simulations show that the transonic discontinuities develop on a time scale of a plasma poloidal revolution to form an edge density pedestal and a localized velocity shear layer at the pedestal location. While such an MHD pedestal surrounds the entire core, the outboard side of the pedestal is driven by the transonic discontinuity while the inboard side is caused by a poloidal redistribution of the mass. The MHD simulations use a smooth momentum source to drive the poloidal flow. Soon after the flow exceeds the poloidal sound speed, the density pedestal and the velocity shear layer form and persist into a quasi steady state. These results may be relevant to the L-H transition, the early stages of the pedestal and edge transport barrier formation.
Orientation dependence of thermal conductivity in copper-graphene composites
Authors: Jagannadham K.
Published: October 2011

Copper and graphene multilayer films were deposited on a copper substrate. The surface of the multilayer film was covered with another film of copper by electrochemical deposition. An electrically insulating film of polymer followed by films of silicon and yttria-stabilized zirconia were deposited to isolate the sample electrically from a gold heater line deposited on the top. The three-omega method was used to determine the cross-plane thermal conductivity in the sample. The effective planar thermal conductivity in the sample was determined from two gold heater lines deposited adjacent to each other on the surface. The gradient of temperature between the heater lines was evaluated under steady state to determine the planar thermal conductivity. The results show that the cross-plane thermal conductivity in the copper-graphene layers is reduced as a result of the lower thermal conductivity normal to the graphene planes. The planar thermal conductivity in the copper-graphene layers was not reduced below that in copper. The interface thermal resistance between copper and graphene was evaluated from the planar thermal conductivity. The interface thermal resistance either in the cross plane direction or in the planar direction is found to be not a limiting factor for the improvement in the thermal conductivity in the copper-graphene composite films.
Charge transport in hierarchical α-Fe2O3 nanostructures
Authors: Karthik K. R. G. , Mulmudi H. K. , Jinesh K. B. , Mathews N. , Sow C. H. , Huang Y. Z. , Mhaisalkar S. G.
Published: October 2011

Electronic properties of individual polycrystalline α-Fe2O3 nanojunctions have been evaluated. By measuring the space charge limited current, the electron mobilities of the nanorods and nanojunctions were estimated. The mobility of the individual nanojunctions was found to be significantly lower than the individual nanorods. The trend clearly associates with the presence of junctions and grain boundaries in the nanorods. Impedance spectroscopy analysis of individual nanojunctions has been carried out to distinguish between the effects of the grain boundaries and the nanojunctions.
Modeling of concentrating solar thermoelectric generators
Authors: McEnaney Kenneth , Kraemer Daniel , Ren Zhifeng , Chen Gang
Published: October 2011

The conversion of solar power into electricity is dominated by non-concentrating photovoltaics and concentrating solar thermal systems. Recently, it has been shown that solar thermoelectric generators (STEGs) are a viable alternative in the non-concentrating regime. This paper addresses the possibility of STEGs being used as the power block in concentrating solar power systems. STEG power blocks have no moving parts, they are scalable, and they eliminate the need for an external traditional thermomechanical generator, such as a steam turbine or Stirling engine. Using existing skutterudite and bismuth telluride materials, concentrating STEGs can have efficiencies exceeding 10% based on a geometric optical concentration ratio of 45.
Effect of order on the half-metallic gap in Heusler compounds
Authors: Özdoğan K. , Galanakis I.
Published: October 2011

Employing ab initio electronic structure methods we study the effect of order on the half-metallicity of Co2MnAl and Co2MnSi Heusler alloys. The occurrence of Co antisites destroys the half-metallic character, while for any degree of Mn-Al(Si) disorder the half-metallicity is preserved and the total spin magnetic moment is found to obey the Slater-Pauling behavior. In the structures, where Co atoms are nearest-neighbors, there is a region of low density of states around the Fermi level in the majority-spin band and a high degree of spin-polarization is exhibited. Thus the control and minimization of the concentration of Co impurities at antisites is imperative to achieve optimal performance of spintronic devices. Our results agree with available experimental results.
Electronic states at the interface between indium tin oxide and silicon
Authors: Malmbekk H. , Vines L. , Monakhov E. V. , Svensson B. G.
Published: October 2011

Electronic properties and thermal stability of interfacial states between indium tin oxide (ITO) and monocrystalline silicon (Si) have been investigated. ITO films with thicknesses of about 300 nm were deposited by dc magnetron sputtering on n- and p-type (100) Si at room temperature. The samples were then annealed for 30 min at different temperatures in the range 100–600 °C, and the ITO-Si junction was found to exhibit rectifying behavior. Current-voltage (IV), capacitance-voltage (CV), and deep-level transient spectroscopy (DLTS) measurements have been used to electrically characterize the ITO-Si interface. DLTS measurements on p-type Si samples reveal a dominant hole trap at around 0.37 eV above the valence band edge. In the n-type samples, a broad band of electron traps occur in the range 0.1-0.2 eV below the conduction band edge. These electron traps display wide DLTS peaks, indicating a band of electronic energy levels rather than well-defined states originating from isolated point defects. All the traps in both the p- and n-type samples are found to be located near the ITO-Si interface. Investigations of the thermal stability of the observed electronic states show that the dominant hole trap anneal out after 30 min at 250 °C, while the dominant electron traps can be stable up to 500 °C. IV and DLTS measurements demonstrate a clear correlation between the annealing of the dominant electronic states and increase in the junction rectification.
Dynamics of freely moving plates connected by a shallow liquid bridge
Authors: Gat Amir , Navaz Homayun , Gharib Morteza
Published: October 2011

We study the dynamics of freely moving plates connected by a shallow liquid bridge via analytic and experimental methods. The gap between the plates is used as a small parameter within a lubrication approximation, reducing the problem to an Abel equation of the second kind. Analysis of the governing differential equation yields two novel physical phenomena: (1) An impulse-like peak in the force applied by the liquid bridge on the plates, obtained from a uniform asymptotic solution for small capillary numbers. (2) Both linear and non-linear oscillations of the system for the case of surfaces with low wettability, obtained from small perturbations of the system around the equilibrium point. An experimental setup examining the motion of freely moving plates was constructed, yielding experimental data which compared favorably with the analytic results and specifically displayed the predicted oscillations and impulse-like peak of the applied force. The application of the current analysis to the manipulation of solid bodies and possible future research directions are discussed.
Projected quasiparticle theory for molecular electronic structure
Authors: Scuseria Gustavo E. , Jiménez-Hoyos Carlos A. , Henderson Thomas M. , Samanta Kousik , Ellis Jason K.
Published: October 2011

We derive and implement symmetry-projected Hartree-Fock-Bogoliubov (HFB) equations and apply them to the molecular electronic structure problem. All symmetries (particle number, spin, spatial, and complex conjugation) are deliberately broken and restored in a self-consistent variation-after-projection approach. We show that the resulting method yields a comprehensive black-box treatment of static correlations with effective one-electron (mean-field) computational cost. The ensuing wave function is of multireference character and permeates the entire Hilbert space of the problem. The energy expression is different from regular HFB theory but remains a functional of an independent quasiparticle density matrix. All reduced density matrices are expressible as an integration of transition density matrices over a gauge grid. We present several proof-of-principle examples demonstrating the compelling power of projected quasiparticle theory for quantum chemistry.
Diffusion behavior of dual capping layers in TiN/LaN/AlN/HfSiOx/Si stack
Authors: Zheng X. H. , Huang A. P. , Xiao Z. S. , Wang M. , Liu X. Y. , Wu Z. W. , Chu Paul K.
Published: October 2011

The diffusion behavior and interlayer interactions in the LaN/AlN dual capping layers of TiN/LaN/AlN/HfSiOx/Si stacks are investigated. Depth profiling and chemical state analysis performed after partial removal of the TiN gate indicate that Al-O replaces Al-N forming an Al-O dipole layer between the TiN and high-k layer after annealing. Meanwhile, La diffuses into HfSiOx and the La-based dipole is controlled by suppression of O diffusion to the bottom layer. Our results reveal that the properties of the TiN/LaN/AlN/HfSiOx/Si stack can be improved significantly by the dual capping layers.
Factors controlling the energetics of the oxygen reduction reaction on the Pd-Co electro-catalysts: Insight from first principles
Authors: Zuluaga Sebastian , Stolbov Sergey
Published: October 2011

We report here results of our density functional theory based computational studies of the electronic structure of the Pd-Co alloy electrocatalysts and energetics of the oxygen reduction reaction (ORR) on their surfaces. The calculations have been performed for the (111) surfaces of pure Pd, Pd0.75Co0.25 and Pd0.5Co0.5 alloys, as well as of the surface segregated Pd/Pd0.75Co0.25 alloy. We find the hybridization of dPd and dCo electronic states to be the main factor controlling the electrocatalytic properties of Pd/Pd0.75Co0.25. Namely the dPd–dCo hybridization causes low energy shift of the surface Pd d-band with respect to that for Pd(111). This shift weakens chemical bonds between the ORR intermediates and the Pd/Pd0.75Co0.25 surface, which is favorable for the reaction. Non-segregated Pd0.75Co0.25 and Pd0.5Co0.5 surfaces are found to be too reactive for ORR due to bonding of the intermediates to the surface Co atoms. Analysis of the ORR free energy diagrams, built for the Pd and Pd/Pd0.75Co0.25, shows that the co-adsorption of the ORR intermediates and water changes the ORR energetics significantly and makes ORR more favorable. We find the onset ORR potential estimated for the configurations with the O–OH and OH–OH co-adsorption to be in very good agreement with experiment. The relevance of this finding to the real reaction environment is discussed.