bluuebunny/crossref_metadata_2025 huggingface dataset:
In-Person Interaction in AAC: New Perspectives on Utterances, Multimodality, Timing, and Device Design
Authors: Higginbotham D. Jeffery
Published: December 2009

Evidence is accumulating for the language use model in psycholinguistics, the social sciences as well as work in human computer interaction. Recent research in augmentative and alternative communication (AAC) has demonstrated the insufficiency of the sender-receiver model for characterizing augmented interactions. In this paper we will begin to provide a framework for showing how the AAC field may benefit from examining how people perform using language during in-person interaction.
Surface structure and magnetic properties of MnAs epilayers grown on vicinal GaAs(001) substrates
Authors: Graff I. L. , Vidal F. , Marangolo M. , Eddrief M. , Zheng Y. , Etgens V. H.
Published: December 2009

In this study, we have investigated the influence of the vicinality on the surface morphology of MnAs/GaAs(001) epilayers at the nanoscale. The microscopic structure of the MnAs surface is strongly affected by the miscut angle of the substrate, while the characteristic MnAs α−β micronic self-organized stripes pattern remains largely unaffected. Even though the surface morphology is quite different from epilayers deposited on nominal substrates (no miscut), the magnetic properties of the films grown on vicinal substrates are nearly unaltered. That is, the temperature for the onset of the β phase, for decreasing temperature, the coercive field, and the remnant magnetization are similar to films grown on nominal substrates. These findings open interesting prospects concerning the use of MnAs/GaAs(001) epilayers as temperature-dependent striped templates for the subsequent growth of magnetic thin films and the formation of a great variety of nanostructures.
Site-controlled InAs quantum dots grown on a 55 nm thick GaAs buffer layer
Authors: Pfau T. J. , Gushterov A. , Reithmaier J. P. , Cestier I. , Eisenstein G. , Linder E. , Gershoni D.
Published: December 2009

We present site-controlled low density InAs quantum dots grown by molecular beam epitaxy with a template based overgrowth technique allowing enlarged buffer layers upto 55 nm. Growing a seeding layer of InAs quantum dots in etched holes reduces closing of the holes, so that a second layer of InAs quantum dots can be aligned to the holes after a buffer layer overgrowth. Confocal microphotoluminescence measurements show a significant decrease of the low temperature photoluminescence linewidth of the quantum dots to an average value of ∼500 μeV and a minimum width of 460 μeV. This is to be compared to 2 to 4 meV of quantum dots grown on thin buffer layers. This improvement is due to the enlarged distance to residual defects at the overgrown surface.
Curved manifolds with conserved Runge–Lenz vectors
Authors: Ngome J.-P.
Published: December 2009

van Holten’s algorithm is used to construct Runge–Lenz-type conserved quantities, induced by Killing tensors, on curved manifolds. For the generalized Taub-Newman–Unti-Tamburino metric, the most general external potential such that the combined system admits a conserved Runge–Lenz-type vector is found. In the multicenter case, the subclass of two-center metric exhibits a conserved Runge–Lenz-type scalar.
Conductance characteristics of current-carrying d-wave weak links
Authors: Shevchenko S. N.
Published: December 2009

The local quasiparticle density of states in the current-carrying d-wave superconducting structures is studied theoretically. The density of states can be accessed through the conductance of the scanning tunneling microscope. Two particular situations are considered: the current state of a homogeneous film, and a weak link between two current-carrying d-wave superconductors.
Strain-rate sensitivity of the flow stress of ultrafine-grain aluminum at temperatures 4.2–295K
Authors: Isaev N. V. , Grigorova T. V. , Zabrodin P. A.
Published: December 2009

The influence of the grain size on the dislocation interaction mechanisms that control the deformation of aluminum in the temperature range 4.2–295K is studied. For this, samples of coarse-grain (CG) and ultrafine-grain (UFG) aluminum obtained by equi-channel angular pressing were deformed by stretching at constant rate ε̇ as well as in the rate-cycling regime along the deformation curve. The effects of temperature on strain hardening and the stain-rate sensitivity of the flow stress of CG and UFG material are compared. It is shown by means of thermal-activation analysis of the experimental data that the dependence of the rate sensitivity parameter m=[∂lnσ∕∂lnε̇]T on the grain size and temperature of the aluminum is explained by a change of the dislocation mechanisms controlling the plastic deformation of the aluminum. In the temperature interval 4.2–40K the plastic deformation of the UFG and CG aluminum is due to a single mechanism of intersection of forest dislocation. In the interval 120–295K for CG and 77–140K for UFG aluminum the increase in the parameter m is explained by the activation of the mechanism of transverse slip of dislocations. At temperatures above 140K the high rate sensitivity of the stress and low rate of strain hardening of UFG aluminum can be due to the activation of the grain-boundary diffusion and grain-boundary slip-through.
New methodology for simultaneous volumetric and calorimetric measurements: Direct determination of αp and Cp for liquids under pressure
Authors: Casás L. M. , Plantier F. , Bessières D.
Published: December 2009

A new batch cell has been developed to measure simultaneously both isobaric thermal expansion and isobaric heat capacity from calorimetric measurements. The isobaric thermal expansion is directly proportional to the linear displacement of an inner flexible below and the heat capacity is calculated from the calorimetric signal. The apparatus used was a commercial Setaram C-80 calorimeter and together with this type of vessels can be operated up to 20 MPa and in the temperature range of 303.15–523.15 K, In this work, calibration was carried out using 1-hexanol and subsequently both thermophysical properties were determined for 3-pentanol, 3-ethyl-3-pentanol, and 1-octanol at atmospheric pressure, 5 and 10 MPa, and from 303.15 to 423.15 K in temperature. Finally experimental values were compared with the literature in order to validate this new methodology, which allows a very accurate determination of isobaric thermal expansion and isobaric heat capacity.
Compact polarization-insensitive biopolymer multimode interference waveguide splitter
Authors: Zhou J. , Wang Z. Y. , Pun E. Y. B.
Published: December 2009

Compact 1×4 multimode interference splitter with tapered sections has been designed and fabricated based on deoxyribonucleic acid-cetyltrimethylammonium biopolymer material. A multistep processing and reactive ion etching technique have been developed to fabricate the device. There is excellent agreement between experimental and theoretical results and the splitter exhibits low excess loss, negligible polarization dependent loss, and well output uniformity for both TE and TM modes at 1550 nm wavelength.
Gravity induced sedimentation of slender fibers
Authors: Gustavsson K. , Tornberg A.-K.
Published: December 2009

Gravity induced sedimentation of slender, rigid fibers in a highly viscous fluid is investigated by large scale numerical simulations. The fiber suspension is considered on a microscopic level and the flow is described by the Stokes equations in a three dimensional periodic domain. Numerical simulations are performed to study in great detail the complex dynamics of a cluster of fibers. A repeating cycle is identified. It consists of two main phases: a densification phase, where the cluster densifies and grows, and a coarsening phase, during which the cluster becomes smaller and less dense. The dynamics of these phases and their relation to fluctuations in the sedimentation velocity are analyzed. Data from the simulations are also used to investigate how average fiber orientations and sedimentation velocities are influenced by the microstructure in the suspension. The dynamical behavior of the fiber suspension is very sensitive to small random differences in the initial configuration and a number of realizations of each numerical experiment are performed. Ensemble averages of the sedimentation velocity and fiber orientation are presented for different values of the effective concentration of fibers and the results are compared to experimental data. The numerical code is parallelized using the Message Passing Instructions (MPI) library and numerical simulations with up 800 fibers can be run for very long times which is crucial to reach steady levels of the averaged quantities. The influence of the periodic boundary conditions on the process is also carefully investigated.
Inducing chalcogenide phase change with ultra-narrow carbon nanotube heaters
Authors: Xiong Feng , Liao Albert , Pop Eric
Published: December 2009

Carbon nanotube (CNT) heaters with sub-5 nm diameter induce highly localized phase change in Ge2Sb2Te5 (GST) chalcogenide. A significant reduction in resistance of test structures is measured as the GST near the CNT heater crystallizes. Effective GST heating occurs at currents as low as 25 μA, significantly lower than in conventional phase change memory with metal electrodes (0.1–0.5 mA). Atomic force microscopy reveals nucleation sites associated with phase change in GST around the CNT heater. Finite element simulations confirm electrical characteristics consistent with the experiments, and reveal the current and phase distribution in GST.
Graphene field effect transistors with parylene gate dielectric
Authors: Sabri S. S. , Lévesque P. L. , Aguirre C. M. , Guillemette J. , Martel R. , Szkopek T.
Published: December 2009

We report the fabrication and characterization of graphene field effect transistors with parylene back gate and exposed graphene top surface. A back gate stack of 168 nm parylene on 94 nm thermal silicon oxide permitted optical reflection microscopy to be used for identifying exfoliated graphene flakes. Room temperature mobilities of 10 000 cm2/Vs at 1012/cm2 electron/hole densities were observed in electrically contacted graphene. Parylene gated devices exhibited stable neutrality point gate voltage under ambient conditions and less hysteresis than that observed in graphene flakes directly exfoliated on silicon oxide.
Effect of hybrids, plant density and fertility levels on nutrient concentration, uptake and productivity of pearl millet in semi arid environment
Authors: Rana V. S. , Rathore B. S. , Nanwal R. K. , Kumar Ashwani , Vasist R.
Published: December 2009

A Field experiment was conducted at Crop Research Farm, Chaudhary Charan Singh Haryana Agricultural University, Hisar, during the kharif seasons of 2004 and 2005 to find out suitable spacing for pearl millet hybrids along with N and P levels so as to increase the productivity of pearl millet. The experiment was laid out in split plot design allocating combinations of two hybrids and three plant densities in main plots and four fertility levels in sub plots with three replications. Highest pooled grain yield was recorded by HHB 67-2. Sowing pearl millet at 45x12 cm spacing produced highest pooled grain and stover yield. Application of 90 kg N + 45 kg P2O5 ha–1 resulted maximum pooled grain and stover yield and was at par with 60 kg N + 30 kg P2O5 ha–1. HHB 67-2 had significantly higher total uptake over HHB 67. Wider spacing of 60x12 cm had higher NPK content but 45x12 cm resulted into higher total uptake of NPK. NPK content and uptake was found higher when pearl millet was fertilized with 90 kg N + 45 kg P2O5 ha–1.
Dune formation under bimodal winds
Authors: Parteli Eric J. R. , Durán Orencio , Tsoar Haim , Schwämmle Veit , Herrmann Hans J.
Published: December 2009

The study of dune morphology represents a valuable tool in the investigation of planetary wind systems—the primary factor controlling the dune shape is the wind directionality. However, our understanding of dune formation is still limited to the simplest situation of unidirectional winds: There is no model that solves the equations of sand transport under the most common situation of seasonally varying wind directions. Here we present the calculation of sand transport under bimodal winds using a dune model that is extended to account for more than one wind direction. Our calculations show that dunes align longitudinally to the resultant wind trend if the angle θ
w
between the wind directions is larger than 90°. Under high sand availability, linear seif dunes are obtained, the intriguing meandering shape of which is found to be controlled by the dune height and by the time the wind lasts at each one of the two wind directions. Unusual dune shapes including the “wedge dunes” observed on Mars appear within a wide spectrum of bimodal dune morphologies under low sand availability.
Polycomb Repressive Complex 2 and Trithorax modulate
Drosophila
longevity and stress resistance
Authors: Siebold Alex P. , Banerjee Rakhee , Tie Feng , Kiss Daniel L. , Moskowitz Jacob , Harte Peter J.
Published: December 2009

Polycomb Group (PcG) and Trithorax Group (TrxG) proteins are key epigenetic regulators of global transcription programs. Their antagonistic chromatin-modifying activities modulate the expression of many genes and affect many biological processes. Here we report that heterozygous mutations in two core subunits of Polycomb Repressive Complex 2 (PRC2), the histone H3 lysine 27 (H3K27)-specific methyltransferase E(Z) and its partner, the H3 binding protein ESC, increase longevity and reduce adult levels of trimethylated H3K27 (H3K27me3). Mutations in
trithorax
(
trx
), a well known antagonist of Polycomb silencing, elevate the H3K27me3 level of
E(z)
mutants and suppress their increased longevity. Like many long-lived mutants,
E(z)
and
esc
mutants exhibit increased resistance to oxidative stress and starvation, and these phenotypes are also suppressed by
trx
mutations. This suppression strongly suggests that both the longevity and stress resistance phenotypes of PRC2 mutants are specifically due to their reduced levels of H3K27me3 and the consequent perturbation of Polycomb silencing. Consistent with this, long-lived
E(z)
mutants exhibit derepression of
Abd-B
, a well-characterized direct target of Polycomb silencing, and
Odc1
, a putative direct target implicated in stress resistance. These findings establish a role for PRC2 and TRX in the modulation of organismal longevity and stress resistance and indicate that moderate perturbation of Polycomb silencing can increase longevity.
Scanned-probe detection of electron spin resonance from a nitroxide spin probe
Authors: Moore Eric W. , Lee SangGap , Hickman Steven A. , Wright Sarah J. , Harrell Lee E. , Borbat Peter P. , Freed Jack H. , Marohn John A.
Published: December 2009

We report an approach that extends the applicability of ultrasensitive force-gradient detection of magnetic resonance to samples with spin-lattice relaxation times (
T
1
) as short as a single cantilever period. To demonstrate the generality of the approach, which relies on detecting either cantilever frequency or phase, we used it to detect electron spin resonance from a
T
1
= 1 ms nitroxide spin probe in a thin film at 4.2 K and 0.6 T. By using a custom-fabricated cantilever with a 4 μ
m
-diameter nickel tip, we achieve a magnetic resonance sensitivity of 400 Bohr magnetons in a 1 Hz bandwidth. A theory is presented that quantitatively predicts both the lineshape and the magnitude of the observed cantilever frequency shift as a function of field and cantilever-sample separation. Good agreement was found between nitroxide
T
1
's measured mechanically and inductively, indicating that the cantilever magnet is not an appreciable source of spin-lattice relaxation here. We suggest that the new approach has a number of advantages that make it well suited to push magnetic resonance detection and imaging of nitroxide spin labels in an individual macromolecule to single-spin sensitivity.
Building biological memory by linking positive feedback loops
Authors: Chang Dong-Eun , Leung Shelly , Atkinson Mariette R. , Reifler Aaron , Forger Daniel , Ninfa Alexander J.
Published: December 2009

A common topology found in many bistable genetic systems is two interacting positive feedback loops. Here we explore how this relatively simple topology can allow bistability over a large range of cellular conditions. On the basis of theoretical arguments, we predict that nonlinear interactions between two positive feedback loops can produce an ultrasensitive response that increases the range of cellular conditions at which bistability is observed. This prediction was experimentally tested by constructing a synthetic genetic circuit in
Escherichia coli
containing two well-characterized positive feedback loops, linked in a coherent fashion. The concerted action of both positive feedback loops resulted in bistable behavior over a broad range of inducer concentrations; when either of the feedback loops was removed, the range of inducer concentrations at which the system exhibited bistability was decreased by an order of magnitude. Furthermore, bistability of the system could be tuned by altering growth conditions that regulate the contribution of one of the feedback loops. Our theoretical and experimental work shows how linked positive feedback loops may produce the robust bistable responses required in cellular networks that regulate development, the cell cycle, and many other cellular responses.
On implementing maximum economic yield in commercial fisheries
Authors: Dichmont C. M. , Pascoe S. , Kompas T. , Punt A. E. , Deng R.
Published: December 2009

Economists have long argued that a fishery that maximizes its economic potential usually will also satisfy its conservation objectives. Recently, maximum economic yield (MEY) has been identified as a primary management objective for Australian fisheries and is under consideration elsewhere. However, first attempts at estimating MEY as an actual management target for a real fishery (rather than a conceptual or theoretical exercise) have highlighted some substantial complexities generally unconsidered by fisheries economists. Here, we highlight some of the main issues encountered in our experience and their implications for estimating and transitioning to MEY. Using a bioeconomic model of an Australian fishery for which MEY is the management target, we note that unconstrained optimization may result in effort trajectories that would not be acceptable to industry or managers. Different assumptions regarding appropriate constraints result in different outcomes, each of which may be considered a valid MEY. Similarly, alternative treatments of prices and costs may result in differing estimates of MEY and their associated effort trajectories. To develop an implementable management strategy in an adaptive management framework, a set of assumptions must be agreed among scientists, economists, and industry and managers, indicating that operationalizing MEY is not simply a matter of estimating the numbers but requires strong industry commitment and involvement.
The development and institutionalization of Romani representation and administration. Part 3c: religious, governmental, and non-governmental institutions (1945–1970)
Authors: Klímová-Alexander Ilona
Published: December 2009

This article is the fifth and final in a Nationalities Papers series providing an overview of the development of Romani political group representation and administration, from the arrival of Roma to Europe up to 1971, the landmark year of modern transnational Romani politics. The article concentrates on the period between the Second World War and 1970 and the emergence of the following phenomena which distinguish this period from those covered in the previous articles: some limited Romani participation in non-Romani mainstream political or administrative structures, an international Romani evangelical movement, reconciliation between Romani political representation and the Catholic Church, national institutions created by various governments to aid the administration of policies on Roma and rapid growth of non-governmental organizations addressing Romani issues.
Lives on the border: language and culture in the lives of ethnic Russian women in Baltinava, Latvia
Authors: Cara Olga
Published: December 2009

This study draws on ethnographic research conducted in a small village, Baltinava in Latvia, 2.5 kilometres from the border with Russia. The research examines how ethnic Russian women create a specific Latvian Russian identity by contrasting themselves from ethnic Latvians and Russians who live in Russia and identifying with both groups at the same time. To narrate their lives and to make them meaningful, real and/or perceived “attributes” are combined to draw boundaries between “us” and “them.” Thus, the same thing such as language can be used not only both to distinguish themselves from Russians in Russia or Latvians but also to form coherent identities and to emphasize similarities. This study suggests that ethnicities cannot be reduced to a list of set ethnic groups that are very often used in official government statistics. Ethnic identities have to be viewed as fluid and situational. Moreover, this study shows the dialectic nature of ethnicity. On the one hand, external political, historical and social processes create and recreate ethnic categories and definitions. Yet, on the other hand, the women in this study are active agents creating meaningful and symbolic ethnic boundaries.
The paradox of Solidarity's legacy: contested values in Poland's transitional politics
Authors: Bielasiak Jack
Published: December 2009

Poland's post-communist development is often depicted as a contrast between a unified, engaged society of pre-1989 and a passive, divisive society of post-1989. What explains the displacement of political solidarity with a fragmented political scene? A factor specific to Poland is rooted in the struggle of Solidarity against communist power. The consequences are subsequent attempts to appropriate the values of Solidarność as political capital by competing political voices, leading to contestation about the nature of the country. This normative discourse was evident first in the post-communist divide, between forces stemming from the former communist regime and those affiliated with the opposition. More recently, the saliency of the post-communist division has receded, and a new contested discourse has surfaced among voices coming out of the Solidarity tradition. This rhetoric seeks to define a contrast between a “Solidaristic Poland” dedicated to traditional and Christian values affirming notions of exclusivity and superiority, and a “liberal Poland” dedicated to market and pluralist principles based on competition and individualism. In both political divides, the legacy of Solidarity provides useful political capital to advance distinctive visions of Poland.
Complements or Conflicts: Conceptions of Discussion and Multicultural Literature in a Teachers-as-Readers Discussion Group
Authors: Smith Michael W. , Strickland Dorothy S. , Carman John , Dover Denise , Fiegenbaum Bruce , Hess Ronald , Perez-Torres Sonia , Pheffer Marcia , Richards Pat , Schiffner Pat , Smith Louise , Spencer Monica , Szep Kathy , Temperini Richard
Published: December 2009

We examine the effectiveness of a teachers-as-readers discussion group in achieving its two major goals: suggesting how teachers can use multicultural literature to foster an ethical respect for others and engaging teachers in conversations about multicultural literature that challenge the patterns of discourse that prevail in school discussions of literature. Teachers of diverse backgrounds from urban elementary schools joined us for monthly meetings in which we discussed multicultural literature. The teachers also wrote in response to a journal prompt we provided. The analyses of the teachers' writing and the discussions suggest that although the group was successful in engaging teachers in discussions that challenge the patterns of discourse that typify school discussions of literature, that success may have come at the expense of achieving the goal of demonstrating that multicultural literature can foster an ethical respect for others. Our study has caused us to reexamine the assumptions with which we began our work, for it suggests that goals we once thought to be complementary may, at least to some extent, stand in conflict.
Portfolios as Sites of Learning: Reconceptualizing the Connections to Motivation and Engagement
Authors: Clark Caroline , Chow-Hoy Todd K. , Herter Roberta J. , Moss Pamela A.
Published: December 2009

In this qualitative study, we examine how students' participation in the process of constructing portfolios may affect their motivation for and engagement in literacy learning. Research that is based on the “wisdom of practice” continues to emphasize the value of portfolios and portfolio-based assessment. Few studies, however, articulate an explicit theoretical frame for viewing portfolios and considering their effectiveness. This study grounds portfolio practices in 2 bodies of literature that lend theoretical support to their importance, and then extends outward to include literature that addresses the social construction of meaning and the situated nature of learning. Using vignettes of students from an urban high school, we lay out our initial understandings of portfolios and our a priori assumptions about the concepts of motivation and engagement; we articulate our emerging theory around process portfolios, and trace our processes of reading and interpreting the data; we explain how our theory has evolved and lead us to a new set of literature that broadens the focus of motivation and engagement to include not only the individual student but also other sociocultural factors; and, finally, we discuss the implications of this work for practitioners, researchers, and policy makers.
Reflection and Learning to Teach Reading: A Critical Review of Literacy and General Teacher Education Studies
Authors: Roskos Kathleen , Vukelich Carol , Risko Victoria
Published: December 2009

Much has been hoped for and said about reflection as an essential attribute of effective literacy teaching. Equally as much remains muddled and confused, however, as to its purpose, development, and role in preparing new teachers of reading. How to help aspiring teachers become more reflective about their literacy teaching across the preparatory years is not clear, and proven strategies for improving reflection through professional education are lacking. This article provides a comparative analysis of 54 reflection studies {18 literacy; 36 general teacher education) with the goal of clarifying the concept of reflection as studied in the literacy field and for informing future research. An inductive paradigmatic analysis produced descriptive observations that highlight similarities and differences between the two data sets and five interpretive patterns that characterize researchers' conceptualizations and problem solving. Several guidelines are recommended for conducting research that deepens understanding of the concept and informs reading educators in their practice.
A Stimulus-Response Analysis of Letter Reversals
Authors: Nelson Rosemery O. , Peoples Arthur
Published: December 2009

Kindergarten, first, second, and third grade children (n = 36 per grade level) gave eight types of responses to five categories of letter stimuli, including high and low confusion capital and lower-case letters and frequently reversed letters. An error analysis of these normative data revealed that reversal letters produced more errors than other types of graphic stimuli only for kindergarten children. There was a similar pattern of errors in response to both reversal and other types of letter stimuli: Number of errors deceased as grade level increased; there were no sex differences; and the eight response types produced differing numbers of errors. It was suggested that letter reversals be remediated by first ascertaining the response modes in which letter reversals occur for each child.
Use of Self-Questioning with a Computer-Mediated Text System and Measures of Reading Performance
Authors: MacGregor S. Kim
Published: December 2009

This study investigated the effects of a computer-mediated text system (CTS), designed to facilitate use of questioning strategies, on third-grade students' performance on vocabulary, comprehension, and prediction measures. The subjects were 48 third-grade average and good readers assigned randomly to one of four treatment conditions (three experimental and one control). Students in the experimental conditions read passages using the CTS and were trained to generate questions for clarification and/or focus of attention. Students in the control condition read passages printed on paper and did not receive any questioning training. The Nelson Reading Skills Test and an assessment of ability to predict reading performance were administered both before and after the treatment. Results supported the hypothesis that the CTS would be an effective medium for teaching students to generate questions to improve reading performance. Additional findings revealed that average readers made significantly greater gains than good readers in comprehension and vocabulary knowledge, whereas good readers made greater gains in ability to predict vocabulary performance. These findings indicated that students of average reading ability can learn how to use a reading strategy and apply it to a reading task. The results of the relation between computer feedback to student-generated questions and subsequent reading performance are also discussed. Outcomes of this study suggest the need for future research on the use of computers in the understanding and enhancement of the reading process.
Percentage of Unknown Vocabulary Words in Text as a Function of the Relative Difficulty of the text: Implications for Instruction
Authors: Carver Ronald P.
Published: December 2009

The relationship between the relative difficulty of passages and the number of unknown words in passages was investigated. In Study I, 219 students in Grades 3, 4, 5, and 6 were given 100-word passages sampled from textbooks and library books (trade books) and then asked to underline each word that they did not know. In Study II, 60 graduate students were given a similar task involving 120 passages at the following levels of difficulty: junior high, senior high, college, and graduate school. Relative difficulty (or relative easiness) was determined from the difference between a measure of the reading ability of the student in grade equivalent (GE) units and a measure of the difficulty level of the material in GE units. The results from both Study I and Study II can be summarized as follows: (a) when the material is relatively easy then close to 0% will be unknown basic words, (b) when the material is relatively hard, then 2% or more will be unknown basic words, and (c) when the difficulty of the material is matched closely to the ability of the reader, then around 1% will be unknown basic words. These findings do not support the theory that free reading results in large vocabulary growth because free reading is likely to involve relatively easy material that contains few, if any, unknown words. Indeed, these findings call into question the practice of devoting large amounts of classroom time to free reading if the purpose is to increase vocabulary or reading level.
The Impact of the Journal of Reading Behavior on Reading Scholarship
Authors: Mckenna Michael C. , Robinson Richard D.
Published: December 2009

The Social Science Citation Index was used to gather data concerning the frequency with which articles published in volumes 1 to 25 of the Journal of Reading Behavior have been cited in professional journals. The nature and range of those citations were also examined. These data were used to track the impact of the journal over the first 25 years of its history and to identify the 30 most frequently cited articles. These were analyzed by content, and the top 10 were examined in greater detail. A summary and a recommendation are offered.
Outcome measures for aphasia therapy: It's not what you do, it's the way that you measure it
Authors: Hesketh Anne , Hopcutt Beverley
Published: December 2009

The development of outcome measures is now seen as crucial within the National Health Service (NHS), and the outcome of aphasia therapy is an area which has for some years been under particular scrutiny. Many districts have developed their own measures and others have taken part in cross‐district pilot schemes, but it is not clear how widely used measures are, nor what form they take. This paper presents the results of a questionnaire survey of speech and language therapy services in England and Wales regarding their use of outcome measures for aphasia therapy. The questionnaire requested factual information about the use of measures, and therapists' opinions of their benefits and drawbacks, and also asked for examples of outcome measures currently in use. We summarise the results of the questionnaire and discuss the therapists' and our own perceptions of the merits of the different approaches reported.
The utility of the Right Hemisphere Language Battery in patients with brain tumours
Authors: Thomson Ann‐Marie , Taylor Robert , Frser Diane , Whittle Ian R.
Published: December 2009

The Right Hemisphere Language Battery (RHLB) (Bryan, 1989) was devised to assess the presence of language disorders in patients with damage to the right cerebral hemisphere and to permit an evaluation of the efficacy of therapeutic techniques. To evaluate the utility and sensitivity of the RHLB in patients with solitary right hemispheric brain tumours 20 patients were assessed before and after neurosurgery. Twenty control subjects with no signs or symptoms of brain disease who were undergoing lumbar spinal surgery were also assessed. On six of the seven RHLB subtests there was no significant difference between the scores obtained preoperatively by patients with right hemispheric brain tumours and the control subjects. There was also no significant change in the scores of the patients with tumours before and after resection of the lesion. The RHLB is therefore not recommended for either evaluating communication deficits or for measuring the efficacy of therapeutic techniques in patients with right hemisphere brain tumours. This study does, however, show that there are statistically significant differences between the control and brain tumour groups on the discourse analysis subtest preoperatively. The implications of the study are discussed together with possible reasons for the findings.
Muscle inactivation of mTOR causes metabolic and dystrophin defects leading to severe myopathy
Authors: Risson Valérie , Mazelin Laetitia , Roceri Mila , Sanchez Hervé , Moncollin Vincent , Corneloup Claudine , Richard-Bulteau Hélène , Vignaud Alban , Baas Dominique , Defour Aurélia , Freyssenet Damien , Tanti Jean-François , Le-Marchand-Brustel Yannick , Ferrier Bernard , Conjard-Duplany Agnès , Romanino Klaas , Bauché Stéphanie , Hantaï Daniel , Mueller Matthias , Kozma Sara C. , Thomas George , Rüegg Markus A. , Ferry Arnaud , Pende Mario , Bigard Xavier , Koulmann Nathalie , Schaeffer Laurent , Gangloff Yann-Gaël
Published: December 2009

Mammalian target of rapamycin (mTOR) is a key regulator of cell growth that associates with raptor and rictor to form the mTOR complex 1 (mTORC1) and mTORC2, respectively. Raptor is required for oxidative muscle integrity, whereas rictor is dispensable. In this study, we show that muscle-specific inactivation of mTOR leads to severe myopathy, resulting in premature death. mTOR-deficient muscles display metabolic changes similar to those observed in muscles lacking raptor, including impaired oxidative metabolism, altered mitochondrial regulation, and glycogen accumulation associated with protein kinase B/Akt hyperactivation. In addition, mTOR-deficient muscles exhibit increased basal glucose uptake, whereas whole body glucose homeostasis is essentially maintained. Importantly, loss of mTOR exacerbates the myopathic features in both slow oxidative and fast glycolytic muscles. Moreover, mTOR but not raptor and rictor deficiency leads to reduced muscle dystrophin content. We provide evidence that mTOR controls dystrophin transcription in a cell-autonomous, rapamycin-resistant, and kinase-independent manner. Collectively, our results demonstrate that mTOR acts mainly via mTORC1, whereas regulation of dystrophin is raptor and rictor independent.
Lipid-regulated sterol transfer between closely apposed membranes by oxysterol-binding protein homologues
Authors: Schulz Timothy A. , Choi Mal-Gi , Raychaudhuri Sumana , Mears Jason A. , Ghirlando Rodolfo , Hinshaw Jenny E. , Prinz William A.
Published: December 2009

Sterols are transferred between cellular membranes by vesicular and poorly understood nonvesicular pathways. Oxysterol-binding protein–related proteins (ORPs) have been implicated in sterol sensing and nonvesicular transport. In this study, we show that yeast ORPs use a novel mechanism that allows regulated sterol transfer between closely apposed membranes, such as organelle contact sites. We find that the core lipid-binding domain found in all ORPs can simultaneously bind two membranes. Using Osh4p/Kes1p as a representative ORP, we show that ORPs have at least two membrane-binding surfaces; one near the mouth of the sterol-binding pocket and a distal site that can bind a second membrane. The distal site is required for the protein to function in cells and, remarkably, regulates the rate at which Osh4p extracts and delivers sterols in a phosphoinositide-dependent manner. Together, these findings suggest a new model of how ORPs could sense and regulate the lipid composition of adjacent membranes.
ISWI is a RanGTP-dependent MAP required for chromosome segregation
Authors: Yokoyama Hideki , Rybina Sofia , Santarella-Mellwig Rachel , Mattaj Iain W. , Karsenti Eric
Published: December 2009

Production of RanGTP around chromosomes induces spindle assembly by activating nuclear localization signal (NLS)–containing factors. Here, we show that the NLS protein ISWI, a known chromatin-remodeling ATPase, is a RanGTP-dependent microtubule (MT)-associated protein. Recombinant ISWI induces MT nucleation, stabilization, and bundling in vitro. In Xenopus culture cells and egg extract, ISWI localizes within the nucleus in interphase and on spindles during mitosis. Depletion of ISWI in egg extracts does not affect spindle assembly, but in anaphase spindle MTs disappear and chromosomes do not segregate. We show directly that ISWI is required for the RanGTP-dependent stabilization of MTs during anaphase independently of its effect on chromosomes. ISWI depletion in Drosophila S2 cells induces defects in spindle MTs and chromosome segregation in anaphase, and the cells eventually stop growing. Our results demonstrate that distinctly from its role in spindle assembly, RanGTP maintains spindle MTs in anaphase through the local activation of ISWI and that this is essential for proper chromosome segregation.
Action at a distance during cytokinesis
Authors: von Dassow George , Verbrugghe Koen J.C. , Miller Ann L. , Sider Jenny R. , Bement William M.
Published: December 2009

Animal cells decide where to build the cytokinetic apparatus by sensing the position of the mitotic spindle. Reflecting a long-standing presumption that a furrow-inducing stimulus travels from spindle to cortex via microtubules, debate continues about which microtubules, and in what geometry, are essential for accurate cytokinesis. We used live imaging in urchin and frog embryos to evaluate the relationship between microtubule organization and cytokinetic furrow position. In normal cells, the cytokinetic apparatus forms in a region of lower cortical microtubule density. Remarkably, cells depleted of astral microtubules conduct accurate, complete cytokinesis. Conversely, in anucleate cells, asters alone can support furrow induction without a spindle, but only when sufficiently separated. Ablation of a single centrosome displaces furrows away from the remaining centrosome; ablation of both centrosomes causes broad, inefficient furrowing. We conclude that the asters confer accuracy and precision to a primary furrow-inducing signal that can reach the cell surface from the spindle without transport on microtubules.
Basal body stability and ciliogenesis requires the conserved component Poc1
Authors: Pearson Chad G. , Osborn Daniel P.S. , Giddings Thomas H. , Beales Philip L. , Winey Mark
Published: December 2009

Centrioles are the foundation for centrosome and cilia formation. The biogenesis of centrioles is initiated by an assembly mechanism that first synthesizes the ninefold symmetrical cartwheel and subsequently leads to a stable cylindrical microtubule scaffold that is capable of withstanding microtubule-based forces generated by centrosomes and cilia. We report that the conserved WD40 repeat domain–containing cartwheel protein Poc1 is required for the structural maintenance of centrioles in Tetrahymena thermophila. Furthermore, human Poc1B is required for primary ciliogenesis, and in zebrafish, DrPoc1B knockdown causes ciliary defects and morphological phenotypes consistent with human ciliopathies. T. thermophila Poc1 exhibits a protein incorporation profile commonly associated with structural centriole components in which the majority of Poc1 is stably incorporated during new centriole assembly. A second dynamic population assembles throughout the cell cycle. Our experiments identify novel roles for Poc1 in centriole stability and ciliogenesis.
Cytokinetic astralogy
Authors: Canman Julie C.
Published: December 2009

Division plane specification in animal cells has long been presumed to involve direct contact between microtubules of the anaphase mitotic spindle and the cell cortex. In this issue, von Dassow et al. (von Dassow et al. 2009. J. Cell. Biol. doi:10.1083/jcb.200907090) challenge this assumption by showing that spindle microtubules can effectively position the division plane at a distance from the cell cortex.
PD-L1 regulates the development, maintenance, and function of induced regulatory T cells
Authors: Francisco Loise M. , Salinas Victor H. , Brown Keturah E. , Vanguri Vijay K. , Freeman Gordon J. , Kuchroo Vijay K. , Sharpe Arlene H.
Published: December 2009

Both the programmed death (PD) 1–PD-ligand (PD-L) pathway and regulatory T (T reg) cells are instrumental to the maintenance of peripheral tolerance. We demonstrate that PD-L1 has a pivotal role in regulating induced T reg (iT reg) cell development and sustaining iT reg cell function. PD-L1−/− antigen-presenting cells minimally convert naive CD4 T cells to iT reg cells, showing the essential role of PD-L1 for iT reg cell induction. PD-L1–coated beads induce iT reg cells in vitro, indicating that PD-L1 itself regulates iT reg cell development. Furthermore, PD-L1 enhances and sustains Foxp3 expression and the suppressive function of iT reg cells. The obligatory role for PD-L1 in controlling iT reg cell development and function in vivo is illustrated by a marked reduction in iT reg cell conversion and rapid onset of a fatal inflammatory phenotype in PD-L1−/−PD-L2−/− Rag−/− recipients of naive CD4 T cells. PD-L1 iT reg cell development is mediated through the down-regulation of phospho-Akt, mTOR, S6, and ERK2 and concomitant with the up-regulation of PTEN, all key signaling molecules which are critical for iT reg cell development. Thus, PD-L1 can inhibit T cell responses by promoting both the induction and maintenance of iT reg cells. These studies define a novel mechanism for iT reg cell development and function, as well as a new strategy for controlling T reg cell plasticity.
The origin and development of nonlymphoid tissue CD103+ DCs
Authors: Ginhoux Florent , Liu Kang , Helft Julie , Bogunovic Milena , Greter Melanie , Hashimoto Daigo , Price Jeremy , Yin Na , Bromberg Jonathan , Lira Sergio A. , Stanley E. Richard , Nussenzweig Michel , Merad Miriam
Published: December 2009

CD103+ dendritic cells (DCs) in nonlymphoid tissues are specialized in the cross-presentation of cell-associated antigens. However, little is known about the mechanisms that regulate the development of these cells. We show that two populations of CD11c+MHCII+ cells separated on the basis of CD103 and CD11b expression coexist in most nonlymphoid tissues with the exception of the lamina propria. CD103+ DCs are related to lymphoid organ CD8+ DCs in that they are derived exclusively from pre-DCs under the control of fms-like tyrosine kinase 3 (Flt3) ligand, inhibitor of DNA protein 2 (Id2), and IFN regulatory protein 8 (IRF8). In contrast, lamina propria CD103+ DCs express CD11b and develop independently of Id2 and IRF8. The other population of CD11c+MHCII+ cells in tissues, which is CD103−CD11b+, is heterogenous and depends on both Flt3 and MCSF-R. Our results reveal that nonlymphoid tissue CD103+ DCs and lymphoid organ CD8+ DCs derive from the same precursor and follow a related differentiation program.
Description of an Influenza Vaccination Campaign and Use of a Randomized Survey to Determine Participation Rates
Authors: Tao Xuguang (Grant) , Giampino Janine , Dooley Deborah A. , Humphrey Frances E. , Baron David M. , Bernacki Edward J.
Published: December 2009

Objectives.

To describe the procedures used during an influenza immunization program and the use of a randomized survey to quantify the vaccination rate among healthcare workers with and without patient contact.

Design.

Influenza immunization vaccination program and a randomized survey.

Setting.

Johns Hopkins University and Health System.

Methods.

The 2008/2009 Johns Hopkins Influenza Immunization Program was administered to 40,000 employees, including 10,763 healthcare workers. A 10% randomized sample (1,084) of individuals were interviewed to evaluate the vaccination rate among healthcare workers with direct patient contact.

Results.

Between September 23, 2008, and April 30, 2009, a total of 16,079 vaccinations were administered. Ninety-four percent (94.5%) of persons who were vaccinated received the vaccine in the first 7 weeks of the campaign. The randomized survey demonstrated an overall vaccination rate of 71.3% (95% confidence interval, 68.6%-74.0%) and a vaccination rate for employees with direct patient contact of 82.8% (95% confidence interval, 80.1%-85.5%). The main reason (25.3%) for declining the program vaccine was because the employee had received documented vaccination elsewhere.

Conclusions.

The methods used to increase participation in the recent immunization program were successful, and a randomized survey to assess participation was found to be an efficient means of evaluating the workforce's level of potential immunity to the influenza virus.
Complex dynamics and synchronization of delayed-feedback nonlinear oscillators
Authors: Murphy Thomas E. , Cohen Adam B. , Ravoori Bhargava , Schmitt Karl R. B. , Setty Anurag V. , Sorrentino Francesco , Williams Caitlin R. S. , Ott Edward , Roy Rajarshi
Published: December 2009

We describe a flexible and modular delayed-feedback nonlinear oscillator that is capable of generating a wide range of dynamical behaviours, from periodic oscillations to high-dimensional chaos. The oscillator uses electro-optic modulation and fibre-optic transmission, with feedback and filtering implemented through real-time digital signal processing. We consider two such oscillators that are coupled to one another, and we identify the conditions under which they will synchronize. By examining the rates of divergence or convergence between two coupled oscillators, we quantify the maximum Lyapunov exponents or transverse Lyapunov exponents of the system, and we present an experimental method to determine these rates that does not require a mathematical model of the system. Finally, we demonstrate a new adaptive control method that keeps two oscillators synchronized, even when the coupling between them is changing unpredictably.