bluuebunny/crossref_metadata_2025 huggingface dataset:
Preschool Speech Error Patterns Predict Articulation and Phonological Awareness Outcomes in Children With Histories of Speech Sound Disorders
Authors: Preston Jonathan L. , Hull Margaret , Edwards Mary Louise
Published: May 2013

Purpose

To determine if speech error patterns in preschoolers with speech sound disorders (SSDs) predict articulation and phonological awareness (PA) outcomes almost 4 years later.

Method

Twenty-five children with histories of preschool SSDs (and normal receptive language) were tested at an average age of 4;6 (years;months) and were followed up at age 8;3. The frequency of occurrence of preschool distortion errors, typical substitution and syllable structure errors, and atypical substitution and syllable structure errors was used to predict later speech sound production, PA, and literacy outcomes.

Results

Group averages revealed below-average school-age articulation scores and low-average PA but age-appropriate reading and spelling. Preschool speech error patterns were related to school-age outcomes. Children for whom >10% of their speech sound errors were atypical had lower PA and literacy scores at school age than children who produced <10% atypical errors. Preschoolers who produced more distortion errors were likely to have lower school-age articulation scores than preschoolers who produced fewer distortion errors.

Conclusion

Different preschool speech error patterns predict different school-age clinical outcomes. Many atypical speech sound errors in preschoolers may be indicative of weak phonological representations, leading to long-term PA weaknesses. Preschoolers' distortions may be resistant to change over time, leading to persisting speech sound production problems.
Acoustic Characteristics of Simulated Respiratory-Induced Vocal Tremor
Authors: Lester Rosemary A. , Story Brad H.
Published: May 2013

Purpose

The purpose of this study was to investigate the relation of respiratory forced oscillation to the acoustic characteristics of vocal tremor.

Method

Acoustical analyses were performed to determine the characteristics of the intensity and fundamental frequency (F
0
) for speech samples obtained by Farinella, Hixon, Hoit, Story, and Jones (2006) using a respiratory forced oscillation paradigm with 5 healthy adult males to simulate vocal tremor involving respiratory pressure modulation. The analyzed conditions were sustained productions of /a/ with amplitudes of applied pressure of 0, 1, 2, and 4 cmH
2
O and a rate of 5 Hz.

Results

Forced oscillation of the respiratory system produced modulation of the intensity and F
0
for all participants. Variability was observed between participants and conditions in the change in intensity and F
0
per unit of pressure change, as well as in the mean intensity and F
0
. However, the extent of modulation of intensity and F
0
generally increased as the applied pressure increased, as would be expected.

Conclusion

These findings suggest that individuals develop idiosyncratic adaptations to pressure modulations, which are important to understanding aspects of variability in vocal tremor, and highlight the need to assess all components of the speech mechanism that may be directly or indirectly affected by tremor.
Treatment of Proper Name Retrieval Deficits in an Individual With Temporal Lobe Epilepsy
Authors: Minkina Irene , Ojemann Jeffrey G. , Grabowski Thomas J. , Silkes JoAnn P. , Phatak Vaishali , Kendall Diane L.
Published: May 2013

Purpose

Studies investigating language deficits in individuals with left temporal–lobe epilepsy have consistently demonstrated impairments in proper name retrieval. The aim of this Phase I rehabilitation study was to investigate the effects of a linguistically distributed word retrieval treatment on proper name retrieval in an individual with left temporal–lobe epilepsy.

Method

A 61-year old right-handed male with left temporal–lobe epilepsy (clinical onset at the age of 50) and a deficit in proper name retrieval participated in this study. A single-subject, repeated-probe ABAA design with testing before, immediately after, and 3 months after treatment completion was employed. Proper name retrieval treatment was administered 2 hr per day for 5 days.

Results

Results demonstrated improved naming on trained items and maintenance of trained items 3 months after treatment completion.

Conclusion

Treatment, which took advantage of the individual's undamaged linguistic networks, promoted the reorganization of networks supporting proper naming, leading to improved proper name retrieval. Further research replicating these findings in individuals with varying degrees of proper name retrieval impairment is warranted. Additionally, the mechanism behind the observed improvements in proper name retrieval needs to be investigated further using functional neuroimaging.
Suppression and Narrative Time Shifts in Adults With Right-Hemisphere Brain Damage
Authors: Scharp Victoria L. , Tompkins Connie A.
Published: May 2013

Purpose

This study examined the functioning of a central comprehension mechanism, suppression, in adults with right-hemisphere damage (RHD) while they processed narratives that cued a shift in time frame. In normal language comprehension, mental activation of concepts from a prior time frame is suppressed. The (re)activation of information following a time frame shift was also assessed.

Method

Twenty adults (12 RHD; 8 non brain–damaged) completed a speeded word recognition task while listening to narratives in 2 conditions: shift (“an hour later”) and no shift (“a moment later”).

Results

There was no group difference in suppression for response time proportion data (shift/no shift), but cluster analyses identified a suppression deficit in 8 of the adults with RHD. There was overlap in suppression function at the narrative and lexical levels. The group with RHD was significantly delayed in mentally (re)activating new information after a time shift cue.

Conclusion

Results underscore the generality of suppression functioning in adults with RHD. As such, treatment for a suppression deficit at one level may generalize to another level. An apparent independence of suppression and activation deficits suggests that each may need separate treatment. A better understanding of the nature and boundary conditions of suppression and activation deficits should better inform clinical decisions.
An Aphasia Mentoring Program: Perspectives of Speech-Language Pathology Students and of Mentors With Aphasia
Authors: Purves Barbara A. , Petersen Jill , Puurveen Gloria
Published: May 2013

Purpose

In contrast to clinician-as-expert models, social models of clinical practice typically acknowledge people with aphasia as equal partners in intervention. Given this, there may be a place within speech-language pathology education for programs situating people with aphasia as experts. This paper describes an aphasia mentoring program that was implemented as part of a speech-language pathology graduate program.

Method

Qualitative research methods with thematic analysis of interviews, focus groups, questionnaires, and participant observation were used to develop a description of the mentoring program, including the experiences and perspectives of the participants—both mentors (people with chronic aphasia) and students.

Results

Five themes, including
getting better, aphasia advocacy, group
as
versus
for
therapy, we're a team
, and
focus on mentoring
, emerged from the mentors' data. Five themes, including
shifting the power dynamic, getting to know the person, seeing members as mentors, making classroom learning real
, and
connecting with a community
, emerged from the students' data. There were significant overlaps and intersections between the 2 data sets.

Conclusion

Findings revealed how an aphasia mentoring program that positions people with aphasia as experts can make a significant contribution to student education while supporting mentors' own goals, with implications for improved quality of life.
Nonlinguistic Learning in Individuals With Aphasia: Effects of Training Method and Stimulus Characteristics
Authors: Vallila-Rohter Sofia , Kiran Swathi
Published: May 2013

Purpose

The purpose of the current study was to explore nonlinguistic learning ability in individuals with aphasia, examining the impact of stimulus typicality and feedback on success with learning.

Method

Eighteen individuals with aphasia and 8 nonaphasic controls participated in this study. All participants completed 4 computerized, nonlinguistic category-learning tasks. Learning ability was probed under 2 methods of instruction: feedback-based (FB) and paired-associate (PA). The impact of task complexity on learning ability was also examined, comparing 2 stimulus conditions: typical and atypical. Performance was compared between groups and across conditions.

Results

The controls were able to successfully learn categories under all conditions. For the individuals with aphasia, 2 patterns of performance arose: One subgroup of individuals was able to maintain learning across task manipulations and conditions; the other subgroup demonstrated a sensitivity to task complexity, learning successfully only in the typical training conditions.

Conclusion

Results support the hypothesis that impairments of general learning are present in individuals with aphasia. Some individuals demonstrated the ability to extract category information under complex training conditions; others learned only under conditions that were simplified and that emphasized salient category features. Overall, the typical training condition facilitated learning for all of the participants. Findings have implications for treatment, which are discussed.
Evaluation of Attention Training and Metacognitive Facilitation to Improve Reading Comprehension in Aphasia
Authors: Lee Jaime B. , Sohlberg McKay Moore
Published: May 2013

Purpose

This pilot study investigated the impact of direct attention training combined with metacognitive facilitation on reading comprehension in individuals with aphasia.

Method

A single-subject, multiple baseline design was employed across 4 participants to evaluate potential changes in reading comprehension resulting from an 8-week intervention using Attention Process Training—3 (APT–3). The primary outcome measure was a maze reading task. Pre- and posttesting included attention and reading comprehension measures. Visual inspection of graphed performance data across conditions was used as the primary method of analysis. Treatment effect sizes were calculated for changes in reading comprehension probes from baseline to maintenance phases.

Results

Two of the study's 4 participants demonstrated improvements in maze reading, with corresponding effect sizes that were small in magnitude according to benchmarks for aphasia treatment research. All 4 participants made improvements on select standardized measures of attention.

Conclusion

Interventions that include a metacognitive component with direct attention training may elicit improvements in participants' attention and allocation of resources. Maze passage reading is a repeated measure that appears sensitive to treatment-related changes in reading comprehension. Issues for future research related to measurement, candidacy, and clinical delivery are discussed.
Multi‐physics design of a novel turbine permanent magnet generator used for downhole high‐pressure high‐temperature environment
Authors: Guo Hong , Lv Zhenhua , Wu Zhiyong , Wei Bo
Published: May 2013

Conventional turbine generator with magnetic coupling is becoming difficult to meet large electric power demand because of complex structure, low‐efficiency and lower‐power density in the downhole environment. In this study, a novel stator‐sealed downhole turbine permanent magnet generator is presented. Conventional magnetic coupling is replaced by the separate seals of stator and magnet, allowing drilling fluid flow from the air gap of the generator through the sliding bearings. Then the effective lubrication of bearings and cooling of generator are achieved as well as high power density and pressure balance of the generator. The Halbach array and fractional slot winding are both utilised to further improve the power density, reduce the loss, and keep a lower voltage regulation. A multi‐physics design procedure is proposed in this study involving the electromagnetic, thermal, fluid and stress field for downhole harsh environment. In the design process, the coupling electromagnetic–thermal analysis based on two‐way multiple iterations and the coupling thermal–fluid analysis based on conjugate heat transfer is incorporated to guarantee high accuracy. The experimental data are compared with simulation results to verify the correctness of proposed method and the feasibility of this novel turbine generator for downhole application.
Sinusoidal periodic carrier frequency modulation in reducing electromagnetic noise of permanent magnet synchronous motor
Authors: Xu Yongxiang , Yuan Qingbing , Zou Jinbin , Yao Yanmei , Zhu Guangqi
Published: May 2013

This study introduces a simple method to reduce the electromagnetic noise of permanent magnet synchronous motor (PMSM) fed by pulse‐width modulation (PWM) inverter. The analysed relationship between PMSM electromagnetic noise and current harmonic shows that PMSM electromagnetic noise concentrating on integral multiples of switching frequency is produced by the concentrative current harmonic. To spread the current harmonic spectrum, sinusoidal periodic carrier frequency modulation (PCFM) is presented and discussed theoretically. Simulations and experiments of PMSM fed by PWM inverter are conducted to verify the effectiveness of sinusoidal PCFM in reducing PMSM current harmonic and electromagnetic noise. The most efficient sinusoidal PCFM strategy in alleviating PMSM current harmonic and electromagnetic noise is put forward based on the comparison about reductions of PMSM current harmonic and electromagnetic noise by sinusoidal PCFM with different modulation frequency ratios.
Steady‐state analysis and performance of a brushless doubly fed machine accounting for core loss
Authors: Hashemnia Mohammad Naser , Tahami Farzad , Tavner Peter , Tohidi Sajjad
Published: May 2013

In this study a steady‐state equivalent circuit for a brushless doubly fed machine (BDFM), based upon earlier work, is introduced which takes account of core losses. Based upon some loss approximations, simple relationships have been derived, which show that the synchronous mode operation, in terms of core loss, of the BDFM is similar to the cascaded doubly fed machine. The slip‐dependence of core loss resistances in the equivalent circuit has been investigated by applying energy conservation to derive machine steady‐state torque–speed relations in the presence of core loss. Experimental speed measurements of the BDFM in the simple induction mode were used to identify the core loss resistance values.
Retracted: Design and control of a high‐speed switched reluctance machine with conical magnetic bearings for aircraft application
Authors: Ding Wen , Liu Ling , Lou Jianyong
Published: May 2013

The following article published in IET Electric Power Applications, Ding, Wen; Liu, Ling: Lou, Jianyong: 'Design and control of a high‐speed switched reluctance machine with conical magnetic bearings for aircraft application', IET IET Electric Power Applications, 2013, Volume 7, Issue 3, doi: 10.1049/iet‐epa.2012.0319 has been retracted. Following a rigorous and considered review of this content, this paper has been found to be in violation of the IET’s Policy in Relation to Plagiarism, Infringement of Copyright and Infringement of Moral Rights and Submission to Multiple Publications.
Discrete variable representation in electronic structure theory: Quadrature grids for least-squares tensor hypercontraction
Authors: Parrish Robert M. , Hohenstein Edward G. , Martínez Todd J. , Sherrill C. David
Published: May 2013

We investigate the application of molecular quadratures obtained from either standard Becke-type grids or discrete variable representation (DVR) techniques to the recently developed least-squares tensor hypercontraction (LS-THC) representation of the electron repulsion integral (ERI) tensor. LS-THC uses least-squares fitting to renormalize a two-sided pseudospectral decomposition of the ERI, over a physical-space quadrature grid. While this procedure is technically applicable with any choice of grid, the best efficiency is obtained when the quadrature is tuned to accurately reproduce the overlap metric for quadratic products of the primary orbital basis. Properly selected Becke DFT grids can roughly attain this property. Additionally, we provide algorithms for adopting the DVR techniques of the dynamics community to produce two different classes of grids which approximately attain this property. The simplest algorithm is radial discrete variable representation (R-DVR), which diagonalizes the finite auxiliary-basis representation of the radial coordinate for each atom, and then combines Lebedev-Laikov spherical quadratures and Becke atomic partitioning to produce the full molecular quadrature grid. The other algorithm is full discrete variable representation (F-DVR), which uses approximate simultaneous diagonalization of the finite auxiliary-basis representation of the full position operator to produce non-direct-product quadrature grids. The qualitative features of all three grid classes are discussed, and then the relative efficiencies of these grids are compared in the context of LS-THC-DF-MP2. Coarse Becke grids are found to give essentially the same accuracy and efficiency as R-DVR grids; however, the latter are built from explicit knowledge of the basis set and may guide future development of atom-centered grids. F-DVR is found to provide reasonable accuracy with markedly fewer points than either Becke or R-DVR schemes.
Atomic scale friction of molecular adsorbates during diffusion
Authors: Lechner B. A. J. , de Wijn A. S. , Hedgeland H. , Jardine A. P. , Hinch B. J. , Allison W. , Ellis J.
Published: May 2013

Experimental observations suggest that molecular adsorbates exhibit a larger friction coefficient than atomic species of comparable mass, yet the origin of this increased friction is not well understood. We present a study of the microscopic origins of friction experienced by molecular adsorbates during surface diffusion. Helium spin-echo measurements of a range of five-membered aromatic molecules, cyclopentadienyl, pyrrole, and thiophene, on a copper(111) surface are compared with molecular dynamics simulations of the respective systems. The adsorbates have different chemical interactions with the surface and differ in bonding geometry, yet the measurements show that the friction is greater than 2 ps−1 for all these molecules. We demonstrate that the internal and external degrees of freedom of these adsorbate species are a key factor in the underlying microscopic processes and identify the rotation modes as the ones contributing most to the total measured friction coefficient.
Impact-ionization field-effect-transistor based biosensors for ultra-sensitive detection of biomolecules
Authors: Sarkar Deblina , Gossner Harald , Hansch Walter , Banerjee Kaustav
Published: May 2013

The phenomenon of impact-ionization is proposed to be leveraged for a novel biosensor design scheme for highly efficient electrical detection of biological species. Apart from self-consistent numerical simulations, an analytical formalism is also presented to provide physical insight into the working mechanism and performance of the proposed sensor. It is shown that using the impact-ionization field-effect-transistor (IFET) based biosensor, it is possible to obtain an increase in sensitivity of around 4 orders of magnitude at low biomolecule concentration and around 6 orders of magnitude at high biomolecule concentration compared to that in conventional FET (CFET) biosensors. Moreover, IFET biosensors can lead to significant reduction (around 2 orders of magnitude) in response time compared to CFET biosensors.
Ab initio study of ground and excited states of 6Li40Ca and 6Li88Sr molecules
Authors: Gopakumar Geetha , Abe Minori , Hada Masahiko , Kajita Masatoshi
Published: May 2013

We present quantum-chemical calculations for the ground and some low-lying excited states of isolated LiCa and LiSr molecules using multi-state complete active space second-order perturbation theory (MS-CASPT2). The potential energy curves (PECs) and their corresponding spectroscopic constants, obtained at the spin-free (SF) and spin-orbit (SO) levels, agree well with available experimental values. Our SO-MS-CASPT2 calculation at the atomic limit (R = 100 a.u.) with the largest basis set reproduces experimental atomic excitation energies within 3% for both LiCa and LiSr. In addition, permanent dipole moments and transition dipole moments at the SF level are also obtained. Rovibrational calculations of the ground and selected excited states, together with the spontaneous emission rates, demonstrate that the formation of ultracold LiCa and LiSr molecules in low-lying vibrational levels of the electronic ground state may be possible.
High-frequency annular array with coaxial illumination for dual-modality ultrasonic and photoacoustic imaging
Authors: Filoux Erwan , Sampathkumar Ashwin , Chitnis Parag V. , Aristizábal Orlando , Ketterling Jeffrey A.
Published: May 2013

This paper presents a combined ultrasound and photoacoustic (PA) imaging (PAI) system used to obtain high-quality, co-registered images of mouse-embryo anatomy and vasculature. High-frequency ultrasound (HFU, >20 MHz) is utilized to obtain high-resolution anatomical images of small animals while PAI provides high-contrast images of the vascular network. The imaging system is based on a 40 MHz, 5-element, 6 mm aperture annular-array transducer with a 800 μm diameter hole through its central element. The transducer was integrated in a cage-plate assembly allowing for a collimated laser beam to pass through the hole so that the optical and acoustic beams were collinear. The assembly was mounted on a two-axis, motorized stage to enable the simultaneous acquisition of co-registered HFU and PA volumetric data. Data were collected from all five elements in receive and a synthetic-focusing algorithm was applied in post-processing to beamform the data and increase the spatial resolution and depth-of-field (DOF) of the HFU and PA images. Phantom measurements showed that the system could achieve high-resolution images (down to 90 μm for HFU and 150 μm for PAI) and a large DOF of >8 mm. Volume renderings of a mouse embryo showed that the scanner allowed for visualizing morphologically precise anatomy of the entire embryo along with corresponding co-registered vasculature. Major head vessels, such as the superior sagittal sinus or rostral vein, were clearly identified as well as limb bud vasculature.
Quantum logarithmic Sobolev inequalities and rapid mixing
Authors: Kastoryano Michael J. , Temme Kristan
Published: May 2013

A family of logarithmic Sobolev inequalities on finite dimensional quantum state spaces is introduced. The framework of non-commutative \documentclass[12pt]{minimal}\begin{document}$\mathbb {L}_p$\end{document}Lp-spaces is reviewed and the relationship between quantum logarithmic Sobolev inequalities and the hypercontractivity of quantum semigroups is discussed. This relationship is central for the derivation of lower bounds for the logarithmic Sobolev (LS) constants. Essential results for the family of inequalities are proved, and we show an upper bound to the generalized LS constant in terms of the spectral gap of the generator of the semigroup. These inequalities provide a framework for the derivation of improved bounds on the convergence time of quantum dynamical semigroups, when the LS constant and the spectral gap are of the same order. Convergence bounds on finite dimensional state spaces are particularly relevant for the field of quantum information theory. We provide a number of examples, where improved bounds on the mixing time of several semigroups are obtained, including the depolarizing semigroup and quantum expanders.
Water adsorption and dissociation on α-Fe2O3(0001): PBE+U calculations
Authors: Nguyen Manh-Thuong , Seriani Nicola , Gebauer Ralph
Published: May 2013

Adsorption and dissociation of water on different oxygen- and iron-terminated hematite(0001) surfaces at monolayer coverage have been studied by density-functional theory calculations, including a Hubbard-like+U correction. We considered six possible surface terminations, including four oxygen- and two iron-terminations. Binding energy of water on these terminations can be as large as 1.0 eV. On these terminations the energy barrier for the dissociation of the molecularly adsorbed water is less than 0.3 eV, and in few cases the dissociation is even spontaneous, i.e., without any detectable barrier. Our results thus suggest that water can be adsorbed on the α-Fe2O3(0001) surface dissociatively at room temperature, as previously found by experiment. This study also presents a very first theoretical insight into the adsorption and dissociation of water on all known terminations of the hematite(0001) surface.
Water clusters adsorbed on polycyclic aromatic hydrocarbons: Energetics and conformational dynamics
Authors: Simon Aude , Spiegelman Fernand
Published: May 2013

In this work, we present some classical molecular dynamics (MD) simulations and finite temperature infrared (IR) spectra of water clusters adsorbed on coronene (C24H12), a compact polycyclic aromatic hydrocarbon (PAH). The potential energy surface is obtained within the self-consistent-charge density-functional based tight-binding approach with modifications insuring the correct description of water-water and water-PAH interactions. This scheme is benchmarked for the minimal energy structures of (C24H12)(H2O)n (n = 3–10) against density-functional theory (DFT) calculations and for the low-energy isomers of (H2O)6 and (C6H6)(H2O)3 against correlated wavefunction and DFT calculations. A detailed study of the low energy isomers of (C24H12)(H2O)3, 6 complexes is then provided. On-the-fly Born-Oppenheimer MD simulations are performed in the temperature T range 10–350 K for (C24H12)(H2O)n (n = 3–7) complexes. The description of the evolution of the systems with T is provided with emphasis on (C24H12)(H2O)n (n = 3,6). For T in the range 50–150 K, isomerisation processes are observed and when T increases, a solid-to-liquid phase-change like behavior is shown. The desorption of one water molecule is frequently observed at 300 K. The isomerisation processes are evidenced on the finite temperature IR spectra and the results are presented for (C24H12)(H2O)n (n = 3,6). A signature for the edge-coordination of the water cluster on the PAH is also proposed.
Phase transitions in nanoparticles of BaTiO3 as functions of temperature and pressure
Authors: Han Wei , Zhu Jinlong , Zhang Sijia , Zhang Hui , Wang Xiaohui , Wang Qinglin , Gao Chunxiao , Jin Changqing
Published: May 2013

We studied the temperature and pressure structural stability of 5 nm BaTiO3 particles by using high resolution synchrotron X-ray diffraction, high pressure Raman spectroscopy, and high pressure impedance technique. A coexistence of the tetragonal and orthorhombic phases is observed in 5 nm Barium titanate BaTiO3 particles with weight fractions 67(6.6)% and 33(8.0)% at ambient condition, respectively. In the temperature range from −123 °C to 177 °C, the phase boundaries of 5 nm BaTiO3 are diffusive and several phases coexist. Pressure dependent Raman spectra of 5 nm BaTiO3 indicates that there exist two phase transitions: the first is at 7.5 GPa when the coexisting phases of orthorhombic and tetragonal undergoes transition to tetragonal phase; the second is around 17.3 GPa when the tetragonal transforms to cubic phase. Observed transitions were confirmed by the high pressure impedance property measurement.
Note: Effects of adding a viscosity-increasing 2 nm-size molecule on dielectric relaxation features and the dynamic heterogeneity view
Authors: Khouri Joseph , Johari G. P.
Published: May 2013

To investigate the extent to which dynamic heterogeneity determines the relaxation features, we studied the effect of adding a viscosity-increasing, ∼2 nm size polyhederal oligomeric silsesquioxane (POSS) molecule on dielectric relaxation. Addition of POSS increased the relaxation time of the α-process, τm,α, and decreased the non-exponential response parameter, β, which is compatible with the dynamic heterogeneity view. But β varied monotonically with the composition, and there was little variation of β with the temperature, which seems incompatible with that view. Effects of adding nm-size particles in simulations may reveal how the size of dynamically heterogeneous regions affects τm,α and β.
The near wake of a freely flying European starling
Authors: Kirchhefer Adam J. , Kopp Gregory A. , Gurka Roi
Published: May 2013

The wake of a freely flying European starling (Sturnus vulgaris) has been measured using high speed, time-resolved, particle image velocimetry, simultaneously with high speed cameras which imaged the bird. These have been used to generate vector maps that can be associated with the bird's location and wing configuration in the wind tunnel. Time series of measurements have been expressed as composite wake plots which depict segments of the wing beat cycle for various spanwise locations in the wake. Measurements indicate that downwash is not produced during the upstroke, suggesting that the upstroke does not generate lift. As well, the wake velocities imply the presence of streamwise vortical structures, in addition to tip vortices. These two characteristics indicate similarities between the wake of a bird and the wake of a bat, which may be general features of the wakes of flapping wings.
Simulation of single DNA molecule stretching and immobilization in a de-wetting two-phase flow over micropillar-patterned surface
Authors: Liao Wei-Ching , Hu Xin , Wang Weixiong , James Lee L.
Published: May 2013

We investigate single DNA stretching dynamics in a de-wetting flow over micropillars using Brownian dynamics simulation. The Brownian dynamics simulation is coupled with transient flow field computation through a numerical particle tracking algorithm. The droplet formation on the top of the micropillar during the de-wetting process creates a flow pattern that allows DNA to stretch across the micropillars. It is found that DNA nanowire forms if DNA molecules could extend across the stagnation point inside the connecting water filament before its breakup. It also shows that DNA locates closer to the top wall of the micropillar has higher chance to enter the flow pattern of droplet formation and thus has higher chance to be stretched across the micropillars. Our simulation tool has the potential to become a design tool for DNA manipulation in complex biomicrofluidic devices.
Parasitic nonlinearities in photon pair generation via integrated spontaneous four-wave mixing: Critical problem or distraction?
Authors: Helt L. G. , Steel M. J. , Sipe J. E.
Published: May 2013

We consider integrated photon pair sources based on spontaneous four-wave mixing and derive expressions for the pump powers at which various nonlinear processes become relevant for a variety of source materials and structures. These expressions serve as rules of thumb in identifying reasonable parameter regimes for the design of such sources. We demonstrate that if pump powers are kept low enough to suppress cross-phase modulation, multi-pair events as well as many other nonlinear effects are often also constrained to negligible levels.
Trends in greenhouse gas emissions from dairy cattle in Mexico between 1970 and 2010
Authors: Rendón-Huerta J. A. , Pinos-Rodríguez J. M. , García-López J. C. , Yáñez-Estrada L. G. , Kebreab E.
Published: May 2013

The objective of the present work was to estimate and assess trends in greenhouse gas (GHG) emissions, particularly methane (CH4) and nitrous oxide (N2O), from dairy cows in Mexico from the base year of 1970 to 2010. Empirical and mechanistic models were used to estimate enteric methane emissions based on chemical composition of diets. Methane from manure was calculated using Intergovernmental Panel for Climate Change (IPCC) and US Environmental Protection Agency recommended equations. N2O emission was calculated according to IPCC recommendations. Compared with the 1970s, current management practices using modern dairy cows increased feed conversion efficiency 32% and milk yield 62%. GHG emission intensity (i.e. emissions per unit of product) was reduced 30%, 25% and 30% for CH4, N2O and total emissions, respectively. The study showed that although GHG emissions in absolute terms increased in the past 40 years, emission intensity decreased due to higher level of production. This trend is likely to continue in the future, assuming milk production follows the same increasing trend as in other countries in North America.
Close human presence reduces avoidance behaviour in commercial caged laying hens to an approaching human
Authors: Edwards L. E. , Coleman G. J. , Hemsworth P. H.
Published: May 2013

The quality of human contact that hens are exposed to will determine the degree of fear of humans that they experience. This has consequences for the welfare of commercial laying hens, as hens that are afraid of humans will be regularly exposed to a fear-provoking stressor. Hens can be habituated to human presence using positive or neutral human–animal interactions, although the specific human behaviours that are considered positive or neutral by the hens are still being determined. This experiment investigated whether the proximity or duration of visual contact with a human affected fear of humans in commercial caged laying hens (n = 216). Commercial laying hens were exposed to daily visual human contact at one of three proximities (0, 0.75 or 1.50 m) and one of three durations (2, 30 or 90 s) in a 3 by 3 factorial design for a period of 28 days. Avoidance behaviour was assessed on Days –5, 15 and 30, and the plasma corticosterone response to handling was assessed on Days –5 and Day 30. Visual contact with a stationary human at close proximity (0 m) significantly (P = 0.03) reduced the avoidance response of commercial laying hens to an approaching human, although there was no clear effect of proximity on corticosterone response to handling. The duration of human contact had no effect on avoidance behaviour or corticosterone response. Stockpeople may consider working more closely to the cages in a non-threatening manner to reduce fear of humans in their flock.
Hormonal growth implants affect feed efficiency and expression of residual feed intake-associated genes in beef cattle
Authors: Al-Husseini W. , Gondro C. , Quinn K. , Cafe L. M. , Herd R. M. , Gibson J. P. , Greenwood P. L. , Chen Y.
Published: May 2013

Hormonal growth promotants (HGP) have been used to improve feed conversion ratio (FCR) and growth rates of cattle by modifying protein turnover rates. Residual feed intake (RFI) is correlated with FCR and has been adopted in Australia as a measure of feed efficiency in cattle for the purpose of genetic improvement. Eight genes (AHSG, GHR, GSTM1, INHBA, PCDH19, S100A10, SERPINI2 and SOD3) have been previously reported to be highly associated with RFI and could potentially be used to predict RFI in bulls and steers. In this study, expression levels of these genes in liver tissue of 46 cattle were measured by quantitative real-time PCR. These cattle were part of a larger tenderness gene marker experiment consisting of two breeds (Angus and Brahman); two sexes (steers and heifers) and HGP treatments (implanted vs control). Cattle were measured for growth, feed efficiency, body composition and carcass traits. Results showed the expression of these eight genes was significantly correlated with RFI. However, HGP treatment did not affect RFI or the expression of the RFI-associated genes. HGP treatment increased average daily gain by 20%, improved FCR by 18%, and increased rib eye-muscle area by 7.5%. HGP treatment was effective in improving growth rate, presumably by its known action in the protein turnover mechanism. This mechanism has been hypothesised as one of the regulators of RFI. Lack of effect of HGP treatment on RFI does not support this hypothesis.
Identifying dynamic tuberculosis case-finding policies for HIV/TB coepidemics
Authors: Yaesoubi Reza , Cohen Ted
Published: May 2013

The global tuberculosis (TB) control plan has historically emphasized passive case finding (PCF) as the most practical approach for identifying TB suspects in high burden settings. The success of this approach in controlling TB depends on infectious individuals recognizing their symptoms and voluntarily seeking diagnosis rapidly enough to reduce onward transmission. It now appears, at least in some settings, that more intensified case-finding (ICF) approaches may be needed to control TB transmission; these more aggressive approaches for detecting as-yet undiagnosed cases obviously require additional resources to implement. Given that TB control programs are resource constrained and that the incremental yield of ICF is expected to wane over time as the pool of undiagnosed cases is depleted, a tool that can help policymakers to identify when to implement or suspend an ICF intervention would be valuable. In this article, we propose dynamic case-finding policies that allow policymakers to use existing observations about the epidemic and resource availability to determine when to switch between PCF and ICF to efficiently use resources to optimize population health. Using mathematical models of TB/HIV coepidemics, we show that dynamic policies strictly dominate static policies that prespecify a frequency and duration of rounds of ICF. We also find that the use of a diagnostic tool with better sensitivity for detecting smear-negative cases (e.g., Xpert MTB/RIF) further improves the incremental benefit of these dynamic case-finding policies.
Miniature curved artificial compound eyes
Authors: Floreano Dario , Pericet-Camara Ramon , Viollet Stéphane , Ruffier Franck , Brückner Andreas , Leitel Robert , Buss Wolfgang , Menouni Mohsine , Expert Fabien , Juston Raphaël , Dobrzynski Michal Karol , L’Eplattenier Geraud , Recktenwald Fabian , Mallot Hanspeter A. , Franceschini Nicolas
Published: May 2013

In most animal species, vision is mediated by compound eyes, which offer lower resolution than vertebrate single-lens eyes, but significantly larger fields of view with negligible distortion and spherical aberration, as well as high temporal resolution in a tiny package. Compound eyes are ideally suited for fast panoramic motion perception. Engineering a miniature artificial compound eye is challenging because it requires accurate alignment of photoreceptive and optical components on a curved surface. Here, we describe a unique design method for biomimetic compound eyes featuring a panoramic, undistorted field of view in a very thin package. The design consists of three planar layers of separately produced arrays, namely, a microlens array, a neuromorphic photodetector array, and a flexible printed circuit board that are stacked, cut, and curved to produce a mechanically flexible imager. Following this method, we have prototyped and characterized an artificial compound eye bearing a hemispherical field of view with embedded and programmable low-power signal processing, high temporal resolution, and local adaptation to illumination. The prototyped artificial compound eye possesses several characteristics similar to the eye of the fruit fly
Drosophila
and other arthropod species. This design method opens up additional vistas for a broad range of applications in which wide field motion detection is at a premium, such as collision-free navigation of terrestrial and aerospace vehicles, and for the experimental testing of insect vision theories.
Systematic functional regulatory assessment of disease-associated variants
Authors: Karczewski Konrad J. , Dudley Joel T. , Kukurba Kimberly R. , Chen Rong , Butte Atul J. , Montgomery Stephen B. , Snyder Michael
Published: May 2013

Genome-wide association studies have discovered many genetic loci associated with disease traits, but the functional molecular basis of these associations is often unresolved. Genome-wide regulatory and gene expression profiles measured across individuals and diseases reflect downstream effects of genetic variation and may allow for functional assessment of disease-associated loci. Here, we present a unique approach for systematic integration of genetic disease associations, transcription factor binding among individuals, and gene expression data to assess the functional consequences of variants associated with hundreds of human diseases. In an analysis of genome-wide binding profiles of NFκB, we find that disease-associated SNPs are enriched in NFκB binding regions overall, and specifically for inflammatory-mediated diseases, such as asthma, rheumatoid arthritis, and coronary artery disease. Using genome-wide variation in transcription factor-binding data, we find that NFκB binding is often correlated with disease-associated variants in a genotype-specific and allele-specific manner. Furthermore, we show that this binding variation is often related to expression of nearby genes, which are also found to have altered expression in independent profiling of the variant-associated disease condition. Thus, using this integrative approach, we provide a unique means to assign putative function to many disease-associated SNPs.
Phosphatidylinositol-4,5-biphosphate-dependent rearrangement of TRPV4 cytosolic tails enables channel activation by physiological stimuli
Authors: Garcia-Elias Anna , Mrkonjić Sanela , Pardo-Pastor Carlos , Inada Hitoshi , Hellmich Ute A. , Rubio-Moscardó Fanny , Plata Cristina , Gaudet Rachelle , Vicente Rubén , Valverde Miguel A.
Published: May 2013

Most transient receptor potential (TRP) channels are regulated by phosphatidylinositol-4,5-biphosphate (PIP
2
), although the structural rearrangements occurring on PIP
2
binding are currently far from clear. Here we report that activation of the TRP vanilloid 4 (TRPV4) channel by hypotonic and heat stimuli requires PIP
2
binding to and rearrangement of the cytosolic tails. Neutralization of the positive charges within the sequence
121
KRWRK
125
, which resembles a phosphoinositide-binding site, rendered the channel unresponsive to hypotonicity and heat but responsive to 4α-phorbol 12,13-didecanoate, an agonist that binds directly to transmembrane domains. Similar channel response was obtained by depletion of PIP
2
from the plasma membrane with translocatable phosphatases in heterologous expression systems or by activation of phospholipase C in native ciliated epithelial cells. PIP
2
facilitated TRPV4 activation by the osmotransducing cytosolic messenger 5′-6’-epoxyeicosatrienoic acid and allowed channel activation by heat in inside-out patches. Protease protection assays demonstrated a PIP
2
-binding site within the N-tail. The proximity of TRPV4 tails, analyzed by fluorescence resonance energy transfer, increased by depleting PIP
2
mutations in the phosphoinositide site or by coexpression with protein kinase C and casein kinase substrate in neurons 3 (PACSIN3), a regulatory molecule that binds TRPV4 N-tails and abrogates activation by cell swelling and heat. PACSIN3 lacking the Bin-Amphiphysin-Rvs (F-BAR) domain interacted with TRPV4 without affecting channel activation or tail rearrangement. Thus, mutations weakening the TRPV4–PIP
2
interacting site and conditions that deplete PIP
2
or restrict access of TRPV4 to PIP
2
—in the case of PACSIN3—change tail conformation and negatively affect channel activation by hypotonicity and heat.
Coherent Fano resonances in a plasmonic nanocluster enhance optical four-wave mixing
Authors: Zhang Yu , Wen Fangfang , Zhen Yu-Rong , Nordlander Peter , Halas Naomi J.
Published: May 2013

Plasmonic nanoclusters, an ordered assembly of coupled metallic nanoparticles, support unique spectral features known as Fano resonances due to the coupling between their subradiant and superradiant plasmon modes. Within the Fano resonance, absorption is significantly enhanced, giving rise to highly localized, intense near fields with the potential to enhance nonlinear optical processes. Here, we report a structure supporting the coherent oscillation of two distinct Fano resonances within an individual plasmonic nanocluster. We show how this coherence enhances the optical four-wave mixing process in comparison with other double-resonant plasmonic clusters that lack this property. A model that explains the observed four-wave mixing features is proposed, which is generally applicable to any third-order process in plasmonic nanostructures. With a larger effective susceptibility

χ

(3)
relative to existing nonlinear optical materials, this coherent double-resonant nanocluster offers a strategy for designing high-performance third-order nonlinear optical media.
Genetic screens to identify pathogenic gene variants in the common cancer predisposition Lynch syndrome
Authors: Drost Mark , Lützen Anne , van Hees Sandrine , Ferreira Daniel , Calléja Fabienne , Zonneveld José B. M. , Nielsen Finn Cilius , Rasmussen Lene Juel , de Wind Niels
Published: May 2013

In many individuals suspected of the common cancer predisposition Lynch syndrome, variants of unclear significance (VUS), rather than an obviously pathogenic mutations, are identified in one of the DNA mismatch repair (MMR) genes. The uncertainty of whether such VUS inactivate MMR, and therefore are pathogenic, precludes targeted healthcare for both carriers and their relatives. To facilitate the identification of pathogenic VUS, we have developed an
in cellulo
genetic screen-based procedure for the large-scale mutagenization, identification, and cataloging of residues of MMR genes critical for MMR gene function. When a residue identified as mutated in an individual suspected of Lynch syndrome is listed as critical in such a reverse diagnosis catalog, there is a high probability that the corresponding human VUS is pathogenic. To investigate the applicability of this approach, we have generated and validated a prototypic reverse diagnosis catalog for the MMR gene MutS Homolog 2 (
Msh2
) by mutagenizing, identifying, and cataloging 26 deleterious mutations in 23 amino acids. Extensive in vivo and in vitro analysis of mutants listed in the catalog revealed both recessive and dominant-negative phenotypes. Nearly half of these critical residues match with VUS previously identified in individuals suspected of Lynch syndrome. This aids in the assignment of pathogenicity to these human VUS and validates the approach described here as a diagnostic tool. In a wider perspective, this work provides a model for the translation of personalized genomics into targeted healthcare.