bluuebunny/crossref_metadata_2025 huggingface dataset:
Reliability of Broadband Middle-Ear Power Reflectance in Younger and Older Adults: Application of Generalizability Theory
Authors: Mahoney Marty J. , McFarland Dennis J. , Carpenter MiChelle S. , Rizvi Sabahet , Cacace Anthony T.
Published: February 2014

Purpose

To assess the reliability of broadband middle-ear power reflectance (BMEPR) and transmittance profiles for chirp and tonal stimuli using generalizability theory (GT).

Method

In adults without a history of middle-ear disease, the authors assessed the reliability of BMEPR to chirp and tonal stimuli using a multivariate approach based on an analysis of variance model (GT). For comparisons with other published studies, Pearson's product–moment correlation coefficients (Pearson's
r
) also were used.

Results

Based on GT with chirp stimuli, overall BMEPR measures had good reliability; however, the reliability of individual profiles across frequencies and ears was less than optimal. Lower generalizability coefficients were found when transmittance was evaluated. Test–retest reliability using Pearson's
r
was better for right versus left ears, and mid-frequencies were generally more reliable than those at either extreme of the frequency range. In contrast, tonal stimuli had higher generalizability coefficients and Pearson's
r
values than chirps for all frequencies tested; Pearson's
r
values were also higher for right versus left ears.

Conclusion

The authors extended the use of GT as a preferred way to evaluate reliability of BMEPR and transmittance profiles for chirps and tones because it allows for a more comprehensive evaluation compared with unidimensional pairwise correlations.
Noise Levels Among Spectators at an Intercollegiate Sporting Event
Authors: England Beau , Larsen Jeffery Blythe
Published: February 2014

Purpose

The intensity of noise levels in a basketball arena during games, as well as the hearing sensitivity of attendees, was measured for the purpose of assessing the impact of the noise on hearing thresholds.

Method

Noise levels at 10 intercollegiate basketball games were measured with a dosimeter affixed on the shoulders of attendees. Hearing thresholds and distortion product otoacoustic emissions were measured for 20 participants just before attending a basketball game and within an hour of the end of the game to determine whether changes in hearing thresholds resulted from exposure to the sound levels within the arena during the games.

Results

Participants demonstrated temporary shifts in pure-tone thresholds and reductions in the intensity of their otoacoustic emissions after attendance at 1 of the basketball games. Dosimeter measurements showed that noise at 6 of the 10 basketball games exceeded acceptable intensity levels when compared with a national workplace noise exposure standard.

Conclusion

Although noise intensities, on average, did not exceed workplace exposure standards, universities would be wise to be proactive in warning spectators about the potential dangers of noise exposure at sporting events, make earplugs available to interested spectators, and implement a hearing conservation program for employees working in noise.
Is Central Auditory Processing Disorder Present in Psychosis?
Authors: Iliadou Vasiliki (Vivian) , Apalla Kalliopi , Kaprinis Stergios , Nimatoudis Ioannis , Kaprinis George , Iacovides Apostolos
Published: February 2014

Purpose

The scope of this study was to trace central auditory processing issues in patients with first-episode psychosis using a psychoacoustic test battery approach.

Method

Patients (
n
= 17) and volunteer control subjects (
n
= 17) with no personal or family history of schizophrenia were included in the study on the basis of normal hearing sensitivity. The authors implemented a central auditory processing battery consisting of monaural and binaural tests with verbal and nonverbal stimuli.

Results

Perceptual deficits in both nonverbal and verbal auditory stimuli are reported in this study, with temporal central auditory processing deficits and a mean left-ear advantage documented in the patient group.

Conclusion

This study points to the possibility of the existence of central auditory processing deficits in first-episode psychosis leading to schizophrenia. Audiologists should be aware of the psychiatric research pointing to enhanced verbal memory as a result of auditory training, linking bottom-up remediation with top-down improvement.
Benefits of Auditory Training for Aided Listening by Older Adults
Authors: Dubno Judy R.
Published: February 2014

Purpose

In this article, the authors provide an overview of auditory training programs for aided listening by older adults, review criteria for evaluating effectiveness, summarize results of published studies, report on 2 training programs currently undergoing assessment, and discuss directions and needs for future research.

Method

Experiments are ongoing to evaluate 2 individual, computer-based speech-perception training programs: Indiana University (IU) word-based training and the Speech Perception Assessment and Training System (SPATS). Training and control subjects are older adults with mild-to-severe hearing loss. Subjects train for about 30 hr with monaurally presented, spectrally shaped stimuli (IU) or through loudspeakers with their own hearing aids (SPATS). Displays and feedback use auditory and visual/orthographic cues. Outcome measures include objective measures of speech recognition in noise and other training benefits.

Results

Significant improvements were observed in open-set recognition of trained sounds, words, phrases, and sentences. Large individual differences in training benefit were apparent. Generalization varied with the speech-perception task, competing noise, listening strategy, and pretraining scores.

Conclusions

High-level evidence is needed to support the effectiveness of auditory training for older adults as a supplement to aided listening. Studies are needed to predict who will benefit from specific types of training, to assess compliance and engagement, and to discover benefits beyond communication.
Learning to Listen Again: The Role of Compliance in Auditory Training for Adults With Hearing Loss
Authors: Chisolm Theresa Hnath , Saunders Gabrielle H. , Frederick Melissa T. , McArdle Rachel A. , Smith Sherri L. , Wilson Richard H.
Published: February 2014

Purpose

To examine the role of compliance in the outcomes of computer-based auditory training with the Listening and Communication Enhancement (LACE) program in Veterans using hearing aids.

Method

The authors examined available LACE training data for 5 tasks (i.e., speech-in-babble, time compression, competing speaker, auditory memory, missing word) from 50 hearing-aid users who participated in a larger, randomized controlled trial designed to examine the efficacy of LACE training. The goals were to determine: (a) whether there were changes in performance over 20 training sessions on trained tasks (i.e., on-task outcomes); and (b) whether compliance, defined as completing all 20 sessions, vs. noncompliance, defined as completing less than 20 sessions, influenced performance on parallel untrained tasks (i.e., off-task outcomes).

Results

The majority, 84% of participants, completed 20 sessions, with maximum outcome occurring with at least 10 sessions of training for some tasks and up to 20 sessions of training for others. Comparison of baseline to posttest performance revealed statistically significant improvements for 4 of 7 off-task outcome measures for the compliant group, with at least small (0.2 <d< 0.3) Cohen'sdeffect sizes for 3 of the 4. There were no statistically significant improvements observed for the noncompliant group.

Conclusion

The high level of compliance in the present study may be attributable to use of systematized verbal and written instructions with telephone follow-up. Compliance, as expected, appears important for optimizing the outcomes of auditory training. Methods to improve compliance in clinical populations need to be developed, and compliance data are important to report in future studies of auditory training.
A New Web-Based Tool for Group Audiologic Rehabilitation
Authors: Montano Joseph J. , Preminger Jill E. , Hickson Louise , Gregory Melanie
Published: February 2014

Purpose

The Group Rehabilitation Online Utility Pack (GROUP) was developed to encourage hearing health care professionals to offer group audiologic rehabilitation (GAR) as an integral part of adult hearing rehabilitation and to provide these professionals with the necessary tools to develop and offer GAR in their clinical practice.

Method

The GROUP is a dynamic interactive web-based program that allows visitors to craft and create GAR for their professional use. The tool includes the evidence for implementing GAR, content for preparation and planning, instruction for facilitating groups, and actual GAR activities. Each section includes ethnographic videos, allowing professionals to observe GAR in action.

Conclusion

The GROUP program available on the Ida Institute website was developed with the intent to provide clinicians, academicians, researchers, and students a resource to facilitate the development and implementation of GAR programs throughout the world.
Physiological and Neurobiological Bases of Age-Related Hearing Loss: Biotherapeutic Implications
Authors: Frisina Robert D. , Frisina D. Robert
Published: February 2014

Purpose

The aim of this study was to highlight growing evidence of interactions between hormones and the structure and function of the auditory system.

Method

Recent studies implicating sex hormones and other natural hormones in the modulation of hearing status in age-related hearing loss were reviewed.

Results

Progesterone, a sex hormone, has been shown to have negative effects on the hearing of older women and aging mice, whereas, in contrast, estrogen was found in some cases to have a positive influence. Aldosterone, used in studies of animal models of autoimmune hearing loss, slowed the progression of hearing loss. Follow-up studies in humans revealed that auditory measures varied as serum aldosterone levels shifted within the normal range, in otherwise healthy older subjects. This was true for simple as well as complex auditory tasks (i.e., sound spatial processing), suggesting benefits of aldosterone to postperipheral auditory processing as well. In addition, evidence suggests that this functional hearing improvement occurred in association with anatomical improvements to the stria vascularis—an important site of anatomical change in presbycusis.

Conclusions

Audiology is now at the point where the search for biomedical interventions to modulate or prevent age-related hearing loss can move forward. Such interventions would require multidisciplinary collaborative initiatives by researchers in such areas as drug development, anatomy, auditory physiological and perceptual testing, and drug microdelivery systems.
Developmental Outcomes in Early School-Age Children with Minimal Hearing Loss
Authors: Porter Heather , Sladen Douglas P. , Ampah Steve B. , Rothpletz Ann , Bess Fred H.
Published: February 2014

Purpose

Previous research suggests that school-age children with minimal hearing loss (CMHL) are at risk for a variety of psychoeducational problems. However, CMHL are a heterogeneous group, and the profile of at-risk children is unknown. Data regarding the characteristics of early school-age CMHL are needed to extend previous findings and determine potential risk factors associated with psychoeducational difficulties.

Method

Psychoeducational outcomes were evaluated at baseline and longitudinally in age-matched groups of 27 CMHL (ages 4–10 years) and 26 children with normal hearing (CNH) using assessments of language, reading, behavior, speech recognition in noise, and cognition. Additional analyses were used to identify demographic characteristics among CMHL that are associated with psychoeducational difficulties.

Results

At the earliest age tested, CMHL had greater teacher-rated attention difficulties in the classroom than CNH. Differences in the rate of psychoeducational development were not observed between groups. Among CMHL, psychoeducational difficulties were associated with delays in identification of hearing loss and low maternal education.

Conclusions

Classroom attention abilities should be monitored for early school-age CMHL. Late-identified CMHL and CMHL with low maternal education levels may be in particular need of academic and social support. Continued efforts for early identification of CMHL should be made to improve outcomes for these children.
X-Linked Deafness-2 (DFNX2) Phenotype Associated With a Paracentric Inversion Upstream of
POU3F4
Authors: Anger Gregory J. , Crocker Susan , McKenzie Kyle , Brown Kerry K. , Morton Cynthia C. , Harrison Karen , MacKenzie Jennifer J.
Published: February 2014

Purpose

The authors report on a 7-year-old male, designated
FR,
who has severe sensorineural hearing loss. Features include a round face, hypertelorism, epicanthal folds, and flat nasal root. Although there were early developmental concerns regarding FR, all but his speech delay resolved when he was placed in an educational program that accommodated his hearing loss. Genetic studies were performed to investigate genetic causes for his hearing loss.

Method

History, physical examination, audiologic assessment, and imaging were performed according to usual practice.
FMR1,
GJB2,
GJB6,
and
POU3F4
genes were sequenced. Chromosomal studies consisted of karyotyping and breakpoint analysis by fluorescence in situ hybridization (FISH).

Results

Results from
FMR1,
GJB2,
GJB6,
and
POU3F4
sequencing and echocardiography, electrocardiogram, and abdominal ultrasound were normal. A computed tomography (CT) scan revealed a large fundus of the internal auditory canals and absence of the bony partition between the fundus and the adjacent cochlear turns, with a widened modiolus bilaterally. FR's CT findings were consistent with those described in persons with X-linked deafness-2 (DFNX2) hereditary deafness. FR's karyotype was 46,inv(X)(q13q24),Y.ish inv(X)(XIST+)mat. FISH refined the breakpoints to inv(X)(q21.1q22.3). The Xq21.1 breakpoint was narrowed to a 25-kb region 450 kb centromeric to the DFNX2 gene,
POU3F4
. There are rare case reports of DFNX2 patients with chromosomal rearrangements positioned centromeric to
POU3F4
and no mutations within the gene.

Conclusion

Authors hypothesized that FR's hearing loss was caused by dysregulation of
POU3F4
due to separation from regulatory elements affected by the inversion.
Phase‐sensitive FMCW radar system for high‐precision Antarctic ice shelf profile monitoring
Authors: Brennan Paul V. , Lok Lai Bun , Nicholls Keith , Corr Hugh
Published: February 2014

Ice shelves fringe much of the Antarctic continent, and, despite being up to 2 km thick, are vulnerable to climate change. Owing to their role in helping to control the ice sheet contribution to sea level change there is great interest in measuring the rate at which they are melting into the ocean. This study describes the development and deployment of an ice‐penetrating phase‐sensitive FMCW radar, sufficiently robust and with sufficiently low‐power consumption to be run through the Antarctic winter as a standalone instrument, yet with the stability and mm‐precision needed to detect the very slow changes in ice shelf thickness in this exceptionally demanding environment. A number of elegant processing techniques are described to achieve reliable, high‐precision performance and results presented on field data obtained from the Larsen‐C ice shelf, Antarctica.
Hydroelastic response of a floating runway to cnoidal waves
Authors: Ertekin R. C. , Xia Dingwu
Published: February 2014

The hydroelastic response of mat-type Very Large Floating Structures (VLFSs) to severe sea conditions, such as tsunamis and hurricanes, must be assessed for safety and survivability. An efficient and robust nonlinear hydroelastic model is required to predict accurately the motion of and the dynamic loads on a VLFS due to such large waves. We develop a nonlinear theory to predict the hydroelastic response of a VLFS in the presence of cnoidal waves and compare the predictions with the linear theory that is also developed here. This hydroelastic problem is formulated by directly coupling the structure with the fluid, by use of the Level I Green-Naghdi theory for the fluid motion and the Kirchhoff thin plate theory for the runway. The coupled fluid structure system, together with the appropriate jump conditions are solved in two-dimensions by the finite-difference method. The numerical model is used to study the nonlinear response of a VLFS to storm waves which are modeled by use of the cnoidal-wave theory. Parametric studies show that the nonlinearity of the waves is very important in accurately predicting the dynamic bending moment and wave run-up on a VLFS in high seas.
Feedback control of slowly-varying transient growth by an array of plasma actuators
Authors: Hanson Ronald E. , Bade Kyle M. , Belson Brandt A. , Lavoie Philippe , Naguib Ahmed M. , Rowley Clarence W.
Published: February 2014

Closed-loop feedback control of boundary layer streaks embedded in a laminar boundary layer and experiencing transient growth, which is inherent to bypass boundary layer transition, is experimentally investigated. Streaky disturbances are introduced by a spanwise array of cylindrical roughness elements, and a counter disturbance is provided by a spanwise array of plasma actuators, which are capable of generating spanwise-periodic counter rotating vortices in the boundary layer. Feedback is provided by a spanwise array of shear stress sensors. An input/output model of the system is obtained from measurements of the boundary layer response to steady forcing, and used to design and analyze a proportional-integral controller, which targets a specific spanwise wavenumber of the disturbance. Attention is directed towards a quasi-steady case in which the controller update is slower than the convective time scale. This choice enables addressing issues pertinent to sensing, actuation, and control strategy that are also relevant to the control of unsteady disturbances but without the full complexity of transient effects. The feedback controller and plasma actuators perform well, attenuating the streamwise streaks both in the vicinity of the sensors and farther downstream. The controller remains effective for a range of off-design flow conditions, such as when the free-stream velocity is varied.
Quantum mechanical study of solvent effects in a prototype SN2 reaction in solution: Cl− attack on CH3Cl
Authors: Kuechler Erich R. , York Darrin M.
Published: February 2014

The nucleophilic attack of a chloride ion on methyl chloride is an important prototype SN2 reaction in organic chemistry that is known to be sensitive to the effects of the surrounding solvent. Herein, we develop a highly accurate Specific Reaction Parameter (SRP) model based on the Austin Model 1 Hamiltonian for chlorine to study the effects of solvation into an aqueous environment on the reaction mechanism. To accomplish this task, we apply high-level quantum mechanical calculations to study the reaction in the gas phase and combined quantum mechanical/molecular mechanical simulations with TIP3P and TIP4P-ew water models and the resulting free energy profiles are compared with those determined from simulations using other fast semi-empirical quantum models. Both gas phase and solution results with the SRP model agree very well with experiment and provide insight into the specific role of solvent on the reaction coordinate. Overall, the newly parameterized SRP Hamiltonian is able to reproduce both the gas phase and solution phase barriers, suggesting it is an accurate and robust model for simulations in the aqueous phase at greatly reduced computational cost relative to comparably accurate ab initio and density functional models.
Dispersion effects in Fakir's bed of nails metamaterial waveguides
Authors: Papantonis Stergios , Lucyszyn Stepan , Shamonina Ekaterina
Published: February 2014

The propagation characteristics of electromagnetic waves in waveguides implemented using the “Fakir's bed of nails” are investigated both analytically and numerically. The classical metal walls of a parallel-plate waveguide are replaced by a Fakir's bed of nails metamaterial having arbitrary pin lengths on both walls; treated as a homogenized effective spatially dispersive dielectric. A modal analysis of the electromagnetic fields is presented for the first time, and dispersion expressions for the propagating modes are derived analytically and independently validated with full-wave numerical simulations. An equivalent transmission line model is also given, and similarities with the classical metal-dielectric-metal structure commonly used in optics are discussed.
Effect of bulk aging on surface diffusion of glasses
Authors: Brian Caleb W. , Zhu Lei , Yu Lian
Published: February 2014

The effect of physical aging on surface diffusion has been determined for two organic glasses, Indomethacin and Nifedipine. The two systems exhibit similar aging kinetics typical of organic glasses. Surface diffusivity remains unchanged despite significant bulk aging that nearly equilibrates the systems and increases the bulk relaxation time by orders of magnitude. The finding is relevant for understanding the stability of amorphous materials and the formation of low-energy glasses by vapor deposition.
Optoelectronic simulation of GaAs solar cells with angularly selective filters
Authors: Kraus Tobias , Höhn Oliver , Hauser Hubert , Bläsi Benedikt
Published: February 2014

We discuss the influence of angularly selective filters on thin film gallium arsenide solar cells. For this reason, the detailed balance model was refined to fit our needs with respect to Auger recombination, reflection, transmission, and realistic absorption. For calculating real systems, an approach was made to include optical effects of angularly selective filters into electron-hole dynamic equations implemented in PC1D, a one dimensional solar cell calculation tool. With this approach, we find a relative Voc increase of 5% for an idealized 100 nm GaAs cell, including Auger recombination.
Out of plane anisotropic magnetoresistance and planar Hall effect in epitaxial film of La0.8Sr0.2MnO3
Authors: Naftalis Netanel , Haham Noam , Hoffman Jason , Marshall Matthew S. J. , Ahn C. H. , Klein L.
Published: February 2014

We study the anisotropic magnetoresistance and planar Hall effect of La0.8Sr0.2MnO3 when the field is rotated out of the film plane. We fit the data with a model, which consists of two independent contributions related to (a) the orientation of the magnetization relative to the crystal axes and (b) the orientation of the magnetization relative to the current. We find that the first contribution exhibits a two-fold symmetry, which cannot be explained by the angular dependence of the magnetization magnitude, suggesting an intrinsic source which reflects a deviation from cubic symmetry.
Development of a balanced detector with biased synchronous detection and application to near shot noise limited noise cancelling of supercontinuum pulse light
Authors: Seto Keisuke , Tsukada Toshiaki , Okuda Yoshinao , Tokunaga Eiji , Kobayashi Takayoshi
Published: February 2014

We report on the development of a balanced detector suited for multicolor imaging. The source pulsed light is split into probe and reference pulsed light. The reference pulse is delayed through an optical path and the probe and reference pulses are detected by a single photodetector. The signs of the detected signals of the probe and reference pulses are flipped based on a signal synchronous to the light source. Then, the signals are averaged through a low-pass filter. The output signal is proportional to the intensity difference between the probe and the reference. This balanced detector has two features: (1) both the probe and reference pulsed lights are detected by a single photodetector and (2) a voltage bias on the sign flipping compensates for the optical-intensity unbalance between the probe and reference pulsed lights. The first feature enables the probe and reference pulses to travel along a common optical path from a sample through a spectrograph to the photodetector, which minimizes the intensity unbalance between the probe and reference pulses during imaging and spectroscopy. The second feature ensures the complete balanced-detection in whole wavelength range by compensating for the optical unbalance created by deviations in the splitting ratios of the probe and reference lights at different wavelengths. Although a higher signal to noise ratio (SNR) reached to near shot noise limited SNR is attained by attaching a resonator to the photodetector for pulse repetition, the electrical bias cannot compensate for the optical balance. This unbalance is, however, corrected by adjusting the phase of the synchronous signal. We applied the present balanced detection to a stimulated Raman microscope with supercontinuum probe light and demonstrated its noise cancelling performance through capturing polystyrene beads.
Note: Cryogenic coaxial microwave filters
Authors: Tancredi G. , Schmidlin S. , Meeson P. J.
Published: February 2014

The careful filtering of microwave electromagnetic radiation is critical for controlling the electromagnetic environment for experiments in solid-state quantum information processing and quantum metrology at millikelvin temperatures. We describe the design and fabrication of a coaxial filter assembly and demonstrate that its performance is in excellent agreement with theoretical modelling. We further perform an indicative test of the operation of the filters by making current-voltage measurements of small, underdamped Josephson junctions at 15 mK.
A magnetic contribution to the Hardy inequality
Authors: Ekholm T. , Portmann F.
Published: February 2014

We study the quadratic form associated to the kinetic energy operator in the presence of an external magnetic field in d = 3. We show that if the radial component of the magnetic field does not vanish identically, then the classical lower bound given by Hardy is improved by a non-negative potential term depending on properties of the magnetic field.
Graded Hilbert C*-modules
Authors: Wang Chunxiang
Published: February 2014

The notion of Hilbert C*-modules graded by a semilattice was first introduced in the study of many-body systems. We show the relationship between these Hilbert C*-modules and their homogeneous subspaces. We study the stability of graded Hilbert C*-modules under tensor products and crossed products.
Charge trapping in aligned single-walled carbon nanotube arrays induced by ionizing radiation exposure
Authors: Esqueda Ivan S. , Cress Cory D. , Che Yuchi , Cao Yu , Zhou Chongwu
Published: February 2014

The effects of near-interfacial trapping induced by ionizing radiation exposure of aligned single-walled carbon nanotube (SWCNT) arrays are investigated via measurements of gate hysteresis in the transfer characteristics of aligned SWCNT field-effect transistors. Gate hysteresis is attributed to charge injection (i.e., trapping) from the SWCNTs into radiation-induced traps in regions near the SWCNT/dielectric interface. Self-consistent calculations of surface-potential, carrier density, and trapped charge are used to describe hysteresis as a function of ionizing radiation exposure. Hysteresis width (h) and its dependence on gate sweep range are investigated analytically. The effects of non-uniform trap energy distributions on the relationship between hysteresis, gate sweep range, and total ionizing dose are demonstrated with simulations and verified experimentally.
Interfacial oxygen migration and its effect on the magnetic anisotropy in Pt/Co/MgO/Pt films
Authors: Chen Xi , Feng Chun , Long Wu Zheng , Yang Feng , Liu Yang , Jiang Shaolong , Hua Li Ming , Hua Yu Guang
Published: February 2014

This paper reports the interfacial oxygen migration effect and its induced magnetic anisotropy evolution in Pt/Co/MgO/Pt films. During depositing the MgO layer, oxygen atoms from the MgO combine with the neighboring Co atoms, leading to the formation of CoO at the Co/MgO interface. Meanwhile, the films show in-plane magnetic anisotropy (IMA). After annealing, most of the oxygen atoms in CoO migrate back to the MgO layer, resulting in obvious improvement of Co/MgO interface and the enhancement of effective Co-O orbital hybridization. These favor the evolution of magnetic anisotropy from IMA to perpendicular magnetic anisotropy (PMA). The oxygen migration effect is achieved by the redox reaction at the Co/MgO interface. On the contrary, the transfer from IMA to PMA cannot be observed in Pt/Co/Pt films due to the lack of interfacial oxygen migration.
Controlling the anisotropy and domain structure with oblique deposition and substrate rotation
Authors: Chowdhury N. , Bedanta S.
Published: February 2014

Effect of substrate rotation on anisotropy and domain structure for a thin ferromagnetic film has been investigated in this work. For this purpose Co films with 10 nm thickness have been prepared by sputtering with oblique angle of incidence for various substrate rotations. This method of preparation induces a uniaxial anisotropy due to shadow deposition effect. The magnetization reversal is studied by magneto-optic Kerr effect (MOKE) based microscope in the longitudinal geometry. The Co films prepared by rotating the substrate with 10 and 20 rpm weakens the anisotropy but does not completely give isotropic films. But this leads to high dispersion in local grain anisotropy resulting in ripple and labyrinth domains. It is observed that the substrate rotation has moderate effect on uniaxial anisotropy but has significant effect on the magnetization reversal process and the domain structure.
Micro-cooler enhancements by barrier interface analysis
Authors: Stephen A. , Dunn G. M. , Glover J. , Oxley C. H. , Bajo M. Montes , Cumming D. R. S. , Khalid A. , Kuball M.
Published: February 2014

A novel gallium arsenide (GaAs) based micro-cooler design, previously analysed both experimentally and by an analytical Heat Transfer (HT) model, has been simulated using a self-consistent Ensemble Monte Carlo (EMC) model for a more in depth analysis of the thermionic cooling in the device. The best fit to the experimental data was found and was used in conjunction with the HT model to estimate the cooler-contact resistance. The cooling results from EMC indicated that the cooling power of the device is highly dependent on the charge distribution across the leading interface. Alteration of this charge distribution via interface extensions on the nanometre scale has shown to produce significant changes in cooler performance.
Pattern Specificity of Contrast Adaptation
Authors: Anstis Stuart
Published: February 2014

Contrast adaptation is specific to precisely localised edges, so that adapting to a flickering photograph makes one less sensitive to that same photograph, but not to similar photographs. When two low-contrast photos, A and B, are transparently superimposed, then adapting to a flickering high-contrast B leaves no net afterimage, but it makes B disappear from the A+B picture, which now simply looks like A.
Hydrologic and erosion responses to wildfire along the rangeland–xeric forest continuum in the western US: a review and model of hydrologic vulnerability
Authors: Williams C. Jason , Pierson Frederick B. , Robichaud Peter R. , Boll Jan
Published: February 2014

The recent increase in wildfire activity across the rangeland–xeric forest continuum in the western United States has landscape-scale consequences in terms of runoff and erosion. Concomitant cheatgrass (Bromus tectorum L.) invasions, plant community transitions and a warming climate in recent decades along grassland–shrubland–woodland–xeric forest transitions have promoted frequent and large wildfires, and continuance of the trend appears likely if warming climate conditions prevail. These changes potentially increase overall hydrologic vulnerability by spatially and temporally increasing soil exposure to runoff and erosion processes. Plot and hillslope-scale studies demonstrate burning may increase event runoff or erosion by factors of 2–40 over small-plot scales and more than 100-fold over large-plot to hillslope scales. Reports of flooding and debris flow events from rangelands and xeric forests following burning show the potential risk to natural resources, property, infrastructure and human life. We present a conceptual model for evaluating post-fire hydrologic vulnerability and risk. We suggest that post-fire risk assessment of potential hydrologic hazards should adopt a probability-based approach that considers varying site susceptibility in conjunction with a range of potential storms and that determines the hydrologic response magnitudes likely to affect values-at-risk. Our review suggests that improved risk assessment requires better understanding in several key areas including quantification of interactions between varying storm intensities and measures of site susceptibility, the varying effects of soil water repellency, and the spatial scaling of post-fire hydrologic response across rangeland–xeric forest plant communities.
Defining extreme wildland fires using geospatial and ancillary metrics
Authors: Lannom Karen O. , Tinkham Wade T. , Smith Alistair M.S. , Abatzoglou John , Newingham Beth A. , Hall Troy E. , Morgan Penelope , Strand Eva K. , Paveglio Travis B. , Anderson John W. , Sparks Aaron M.
Published: February 2014

There is a growing professional and public perception that ‘extreme’ wildland fires are becoming more common due to changing climatic conditions. This concern is heightened in the wildland–urban interface where social and ecological effects converge. ‘Mega-fires’, ‘conflagrations’, ‘extreme’ and ‘catastrophic’ are descriptors interchangeably used increasingly to describe fires in recent decades in the US and globally. It is necessary to have consistent, meaningful and quantitative metrics to define these perceived ‘extreme’ fires, given studies predict an increased frequency of large and intense wildfires in many ecosystems as a response to climate change. Using the Monitoring Trends in Burn Severity dataset, we identified both widespread fire years and individual fires as potentially extreme during the period 1984–2009 across a 91.2×106-ha area in the north-western United States. The metrics included distributions of fire size, fire duration, burn severity and distance to the wildland–urban interface. Widespread fire years for the study region included 1988, 2000, 2006 and 2007. When considering the intersection of all four metrics using distributions at the 90th percentile, less than 1.5% of all fires were identified as potentially extreme fires. At the more stringent 95th and 99th percentiles, the percentage reduced to <0.5% and 0.05%. Correlations between area burnt and climatic measures (Palmer drought severity index, temperature, energy release component, duff moisture code and potential evapotranspiration) were observed. We discuss additional biophysical and social metrics that could be included and recommend both the need for enhanced visualisation approaches and to weigh the relative strength or importance of each metric.
Mathematical model of adult stem cell regeneration with cross-talk between genetic and epigenetic regulation
Authors: Lei Jinzhi , Levin Simon A. , Nie Qing
Published: February 2014

Significance

This paper examines how adult stem cells maintain their ability to carry out a complex set of tasks, including tissue regeneration and replacement of defective cells. To do so, stem cell populations must coordinate differentiation, proliferation, and cell death (apoptosis) to maintain an appropriate distribution of epigenetic states. Using the tools of applied mathematics, and borrowing from the theory of intergenerational transfer of resources, this paper shows how control strategies during cell division should be chosen to maximize expected performance, utilizing cross-talk between genetic and epigenetic regulation and performance criteria during homeostasis. Heterogeneous proliferation, a mixed strategy in which not all cells have the same proliferation probability, is shown to increase robustness, and hence long-term performance.
Drugs and Revolution in Iran: Islamic Devotion, Revolutionary Zeal and Republican Means
Authors: Ghiabi Maziyar
Published: February 2014

On 27 June 1979, Ayatollah Khomeini declared, ‘drugs are prohibited” and their trafficking, consumption and “promotion” were against the rules of Islam and could not take place in the Islamic Republic. This ruling, although informal in nature, sanctioned a swift re-direction of Iran's previous approach to narcotic drugs, both in terms of production and consumption. As had happened in 1955, Iran seemed ready to go back to a policy of total prohibition and eradication of opiates, this time under the banner of Islam rather than that of the international drug control regime. Drugs and the politics surrounding them have been a crucial, yet neglected, aspect of the history of modern Iran that have changed the nature of the state bolstering its capacity of social intervention, while hindering its legitimacy, in the Pahlavi, as in the republican, era. By moving on “from the analysis of the state to a concern with the actualities of social subordination”, this article attempts to interpret how social subordination and state coercion were practiced and defied in the making of punishment and welfare in the social body of Iran.
Teachers’ views of their assessment practice
Authors: Atjonen Päivi
Published: February 2014

The main aim of this research was to analyse teachers’ views of pupil assessment. The theoretical framework was based on existing literature on advances and challenges of pupil assessment in regard to support for learning, fairness, educational partnership, feedback, and favourable methods. The data were gathered by means of a questionnaire designed for teachers of comprehensive schools. Teachers were first asked to describe a good (right/fair) and a bad (wrong/unfair) case of pupil assessment selected from the period of latest three years. Second, two lists of factors were presented, and respondents were asked to indicate which were the most influential in making pupil assessment either difficult or easy. One hundred twenty‐six teachers completed and returned the questionnaire. A descriptive, mainly qualitative approach was used to analyse the data. The majority of positive views concerned the use of different assessment methods, an interactive approach, encouraging feedback, and criteria clarification. Negative views dealt with improper assessment methods, level of stringency, badly implemented assessment, and weak grounds for assessment. Three factors made assessment as difficult: interpretation of fairness, pupils with special needs, and pupils’ heterogeneity. On the other hand, versatile assessment methods, curriculum advice, and pupils’ good competencies made teachers’ assessment work easy.
Responding to state failure in Somalia
Authors: Loubser Helge-Mari , Solomon Hussein
Published: February 2014

Strategically located in the horn of Africa, for the past few decades Somalia’s place in the international spotlight has been secured by its complete political and economic failure as a state. The colonisation of this East African mono-ethnic nation by various European nations, and its subsequent devolution into a multitude of mini-fiefdoms, led to attempts to reunite the greater Somali nation after independence was granted. However, although Somalia had one ethnic group and religion, its internal politics was complicated by clan factions. Understanding the clan dynamics is central to understanding the difficulty of ruling Somalia. Siad Barre’s 21-year dictatorship culminated in civil war; the various clans could not achieve consensus on a post-Barre political order. During its 20 years as a leading example of state failure, the international response to Somalia varied from direct military intervention and humanitarian assistance to simply no acknowledgement of the plight of the Somalis. In many cases, the international response addressed the symptoms of failure – treating famine, piracy or the terrorist threat – rather than the root causes of failure.
On asymptotic stability of moving ground states of the nonlinear Schrödinger equation
Authors: Cuccagna Scipio
Published: February 2014

We extend to the case of moving solitons, the result on asymptotic stability of ground states of the NLS obtained by the author in an earlier paper. For technical reasons we consider only smooth solutions. The proof is similar to the earlier paper. However now the flows required for the Darboux Theorem and the Birkhoff normal forms, instead of falling within the framework of standard theory of ODE’s, are related to quasilinear hyperbolic symmetric systems. It is also not obvious that the Darboux Theorem can be applied, since we need to compare two symplectic forms in a neighborhood of the ground states not in

H

1

(

R

3

)

H^{1}(\mathbb {R}^3)

, but rather in the space

Σ
\Sigma

where also the variance is bounded. But the NLS does not preserve small neighborhoods of the ground states in

Σ
\Sigma

.
Multivariable averaging on sparse sets
Authors: LaVictoire P. , Parrish A. , Rosenblatt J.
Published: February 2014

Nonstandard ergodic averages can be defined for a measure-pre- serving action of a group on a probability space, as a natural extension of classical (nonstandard) ergodic averages. We extend the one-dimensional theory, obtaining

L
1

L^1

pointwise ergodic theorems for several kinds of nonstandard sparse group averages, with a special focus on the group

Z

d

\mathbb {Z}^d

. Namely, we extend results for sparse block averages and sparse random averages to their analogues on virtually nilpotent groups, and extend Christ’s result for sparse deterministic sequences to its analogue on

Z

d

\mathbb {Z}^d

. The second and third results have two nontrivial variants on

Z

d

\mathbb {Z}^d

: a “native”

d
d

-dimensional average and a “product” average from the one-dimensional averages.
On behavior of pairs of Teichmüller geodesic rays
Authors: Amano Masanori
Published: February 2014

In this paper, we obtain the explicit limit value of the Teichmüller distance between two Teichmüller geodesic rays which are determined by Jenkins-Strebel differentials having a common end point in the augmented Teichmüller space. Furthermore, we also obtain a condition under which these two rays are asymptotic. This is similar to a result of Farb and Masur.
BAF-1 mobility is regulated by environmental stresses
Authors: Bar Daniel Z. , Davidovich Maya , Lamm Ayelet T. , Zer Hagit , Wilson Katherine L. , Gruenbaum Yosef
Published: February 2014

Barrier to autointegration factor (BAF) is an essential component of the nuclear lamina that binds lamins, LEM-domain proteins, histones, and DNA. Under normal conditions, BAF protein is highly mobile when assayed by fluorescence recovery after photobleaching and fluorescence loss in photobleaching. We report that Caenorhabditis elegans BAF-1 mobility is regulated by caloric restriction, food deprivation, and heat shock. This was not a general response of chromatin-associated proteins, as food deprivation did not affect the mobility of heterochromatin protein HPL-1 or HPL-2. Heat shock also increased the level of BAF-1 Ser-4 phosphorylation. By using missense mutations that affect BAF-1 binding to different partners we find that, overall, the ability of BAF-1 mutants to be immobilized by heat shock in intestinal cells correlated with normal or increased affinity for emerin in vitro. These results show BAF-1 localization and mobility at the nuclear lamina are regulated by stress and unexpectedly reveal BAF-1 immobilization as a specific response to caloric restriction in C. elegans intestinal cells.
Aptamer-guided gene targeting in yeast and human cells
Authors: Ruff Patrick , Koh Kyung Duk , Keskin Havva , Pai Rekha B. , Storici Francesca
Published: February 2014

Gene targeting is a genetic technique to modify an endogenous DNA sequence in its genomic location via homologous recombination (HR) and is useful both for functional analysis and gene therapy applications. HR is inefficient in most organisms and cell types, including mammalian cells, often limiting the effectiveness of gene targeting. Therefore, increasing HR efficiency remains a major challenge to DNA editing. Here, we present a new concept for gene correction based on the development of DNA aptamers capable of binding to a site-specific DNA binding protein to facilitate the exchange of homologous genetic information between a donor molecule and the desired target locus (aptamer-guided gene targeting). We selected DNA aptamers to the I-SceI endonuclease. Bifunctional oligonucleotides containing an I-SceI aptamer sequence were designed as part of a longer single-stranded DNA molecule that contained a region with homology to repair an I-SceI generated double-strand break and correct a disrupted gene. The I-SceI aptamer-containing oligonucleotides stimulated gene targeting up to 32-fold in yeast Saccharomyces cerevisiae and up to 16-fold in human cells. This work provides a novel concept and research direction to increase gene targeting efficiency and lays the groundwork for future studies using aptamers for gene targeting.
Alternative Lengthening of Telomeres is characterized by reduced compaction of telomeric chromatin
Authors: Episkopou Harikleia , Draskovic Irena , Van Beneden Amandine , Tilman Gaëlle , Mattiussi Marina , Gobin Matthieu , Arnoult Nausica , Londoño-Vallejo Arturo , Decottignies Anabelle
Published: February 2014

Proper telomeric chromatin configuration is thought to be essential for telomere homeostasis and stability. Previous studies in mouse suggested that loss of heterochromatin marks at telomeres might favor onset of Alternative Lengthening of Telomeres (ALT) pathway, by promoting homologous recombination. However, analysis of chromatin status at human ALT telomeres has never been reported. Here, using isogenic human cell lines and cellular hybrids, which rely either on telomerase or ALT to maintain telomeres, we show that chromatin compaction is reduced at ALT telomeres and this is associated with a global decrease in telomeric H3K9me3. This, subsequently, leads to upregulation of telomere transcription. Accordingly, restoration of a more condensed telomeric chromatin through telomerase-dependent elongation of short ALT telomeres reduces telomere transcription. We further show that loss of ATRX chromatin remodeler function, a frequent characteristic of ALT cells, is not sufficient to decrease chromatin condensation at telomeres nor to increase the expression of telomeric RNA species. These results offer new insight on telomeric chromatin properties in ALT cells and support the hypothesis that telomeric chromatin decondensation is important for ALT pathway.
Aristotle on Earlier Natural Science
Authors: Hussey Edward
Published: February 2014

In the field of natural science, Aristotle recognizes as his forerunners a select group of theorists such as Heraclitus of Ephesus, Empedocles of Acragas, Anaxagoras of Clazomenae, and Leucippus and Democritus of Abdera. In addition, he mentions in the same contexts some whose claims to be “natural philosophers” are doubtful, yet who deserve notice in the same context, including Parmenides of Elea, Melissus of Samos, the people called Pythagoreans (or “the Italians”), and Plato as the author of the Timaeus. Aristotle takes seriously almost all of these people, treating them as exemplary pioneers and valuable partners in the enterprise of “natural philosophy.” This article examines earlier opinions on certain fundamental questions about the natural world, as treated in the first three books of the Physics and in the first book of the Metaphysics. In Physics II and III, Aristotle represents most if not all of his predecessors as disastrously misunderstanding, in more than one way, the nature underlying the natural world.