bluuebunny/crossref_metadata_2025 huggingface dataset:
A Rolling Grey Model Optimized by Particle Swarm Optimization in Economic Prediction
Authors: Liu Li , Wang Qianru , Wang Jianzhou , Liu Ming
Published: December 2014

Grey system theory has been widely used to forecast the economic data that are often nonlinear, irregular, and nonstationary. Current forecasting models based on grey system theory could adapt to various economic time series data. However, these models ignored the importance of the model parameter optimization and the use of recent data, which lead to poor forecasting accuracy. In this article, we propose a novel forecasting model, called particle swarm optimization rolling grey model (PSO‐RGM(1,1)), based on a rolling mechanism GM with optimized parameters by using the particle swarm optimization algorithm. The simple model is shown to be very effective in forecasting the tertiary industry data sequences, which are short and noisy but regular in secular trend. The experimental results show that PSO‐RGM(1,1) outperforms other commonly used forecasting models on three real economic data sets. Our empirical study shows that PSO is found to be the best overall algorithm to optimize the parameter of RGM compared with other well‐known metaheuristics. Furthermore, we evaluated other variant PSOs and found that single particle PSO outperforms others overall in terms of prediction accuracy, convergence speed, and degree of certainty.
The Relationships between Atrial Electromechanical Delay and CHA2DS2‐VASc Score in Patients Diagnosed with Paroxysmal AF
Authors: Nar Gökay , İnci Sinan , Aksan Gökhan , Soylu Korhan , Demirelli Selami , Nar Rukiye
Published: December 2014

Aim

This study aims to evaluate the relationship between atrial electromechanical delay (AEMD) times and CHA2DS2‐VASc scores in patients diagnosed with paroxysmal atrial fibrillation (PAF).

Materials and Methods

The study included a total of 74 patients, 34 of whom were diagnosed with PAF and 40 were included in the control group. The CHA2DS2‐VASc score was calculated for each patient. Additionally, blood samples were taken from all patients and transthoracic echocardiographic measurements were made. Left atrial mechanical functions and AEMD were calculated.

Results

Mean CHA2DS2‐VASc score measured was 2.24 ± 1.53 in PAF group. There was no significant difference between the groups when the patients were evaluated for baseline characteristics and laboratory parameters (P > 0.05) The echocardiographic evaluation of LA mechanical functions showed that only LA minimum volume (19 ± 6.4 vs. 16.7 ± 4.6, P = 0.02) and LA presystolic volume (28.9 ± 7 vs. 25.1 ± 5.7, P = 0.01) were higher in the PAF group. When AEMD was compared between the groups; lateral PA, septal PA, tricuspid PA, Interatrial EMD, and intraatrial EMD were significantly extended compared to control group (P < 0.001) CHA2DS2‐VASc score was correlated with Lateral atrial PA (P < 0.001, r = 0.524), Septal atrial PA (P < 0.001, r = 0.45), Interatrial EMD (P < 0.001, r = 0.54), and intraatrial EMD (P < 0.001, r = 0.51) times.

Conclusion

The present study shows that AEMD times increase in patients with PAF compared to the control group. Furthermore, this study revealed a correlation between AEMD times and CHA2DS2‐VASc score, as well showed that extended AEMD time may be associated with thromboembolism risk.
The paradox of poverty in rich ecosystems: impoverishment and development in the Amazon of Brazil and Bolivia
Authors: Ioris Antonio A R
Published: December 2014

The article offers an examination of poverty and development in the Amazon, moving beyond the conventional view which places the blame on infrastructure deficiencies, economic isolation or institutional failures. It examines synergistically connected processes that form the persistent poverty‐making geography of the Amazon region. The discussion is based on qualitative research conducted in two emblematic areas in Bolivia (Pando) and Brazil (Pará). The immediate and long‐term causes of socioeconomic problems have been reinterpreted through a politico‐ecological perspective required to investigate the apparent paradox of impoverished areas within rich ecosystems and abundant territorial resources. Empirical results demonstrate that, first, development is enacted through the exercise of hegemony over the entirety of socionature and, second, because poverty is the lasting materiality of development it cannot be alleviated through conventional mechanisms of economic growth based on socionatural hegemony. The main conclusion is that overcoming the imprint of poverty on Amazonian ecosystem entails a radical socioecological reaction. Additionally, the multiple and legitimate demands of low‐income groups do not start from a state of hopeless destitution, but from a position of strength provided by their interaction with the forest ecosystems and with other comparable groups in the Amazon and elsewhere.
BNIP‐2 binds phosphatidylserine, localizes to vesicles, and is transported by kinesin‐1
Authors: Akamatsu Rie , Ishida‐Kitagawa Norihiro , Aoyama Takane , Oka Chio , Kawaichi Masashi
Published: December 2014

BNIP‐2 shows high homology with the Cayman ataxia protein, caytaxin, which functions as a kinesin‐1 adapter bridging cargos and kinesin light chains (KLCs). BNIP‐2 is known to induce cell shape changes when over‐expressed in culture cells, but its physiological functions are mostly unknown. BNIP‐2 interacts with KLC through the conserved WED motif in the N‐terminal region of BNIP‐2. Interaction with KLC and transportation by kinesin‐1 are essential for over‐expressed BNIP‐2 to elongate cells and induce cellular processes. Endogenous BNIP‐2 localizes to the Golgi apparatus, early and recycling endosomes and mitochondria, aligned with microtubules, and moves at a speed compatible with kinesin‐1 transportation. The CRAL–TRIO domain of BNIP‐2 specifically interacts with phosphatidylserine, and the vesicular localization of BNIP‐2 requires interaction with this phospholipid. BNIP‐2 mutants which do not bind phosphatidylserine do not induce morphological changes in cells. These data show that similar to caytaxin, BNIP‐2 is a kinesin‐1 adapter involved in vesicular transportation in the cytoplasm and that association with cargos depends on interaction of the CRAL–TRIO domain with membrane phosphatidylserine.
Community participation for rural health: a review of challenges
Authors: Kenny Amanda , Farmer Jane , Dickson‐Swift Virginia , Hyett Nerida
Published: December 2014

Context

Internationally, community participation is highlighted in health policy reform as good for rural communities. Implicit in this policy is the message that the complexities of the rural environment are too difficult for easy solutions and that community participation will somehow build resilient, self‐determining communities capable of dealing with complex rural access and equity issues and poorer health outcomes. The underpinning proposition is that by giving decision‐making powers to community members, health care will be locally responsive, costs will be contained, and health outcomes will improve. What happens in the practice of enacting community participation in health‐care decision making is less clear.

Objective

Despite the growing body of work that documents different levels and models of community participation, significant gaps that outline the practical challenges inherent in rural community participation remain. In this article, we draw on a body of literature to outline the practical considerations in implementing community participation policy in health settings in rural areas. Through a critical review, we aim to stimulate debate, progress ideas and provide a conceptual representation of the somewhat ‘messy’ nature of rural community participation at a grass‐roots organizational level.

Discussion and conclusion

Based on our analysis of the current literature, we provide a summary of challenges and practical strategies that might mitigate some of these challenges. Our review highlights that despite policymakers suggesting that community participation is good for rural communities, policy enactment must move beyond mandated tokenism for there to be a recognition that meaningful participation is neither easy nor linear.
Internal Capital Markets and the Funding of Subsidiaries of Multinational Banks
Authors: Gulamhussen Mohamed Azzim , Lavrador Isabel Maria Monteiro
Published: December 2014

We study the factors that determine the debt funding of subsidiaries of multinational banks. Our findings indicate that the funding of subsidiaries is determined by the internalization advantages of the parent bank and the home country, in addition to the characteristics of the subsidiary and the host country. Subsidiaries of multinational banks adjust the level of their funding by virtue of their affiliation with their parent's multinational network. Multinational banks may exploit their internalization advantages to secure funding via subsidiaries. Our findings suggest that gaps in regulation and supervision between host and home countries have the potential to undermine the sound functioning of the global financial system.
Effects of role stress on nurses' turnover intentions: The mediating effects of organizational commitment and burnout
Authors: Han Sang‐Sook , Han Jeong‐Won , An Young‐Suk , Lim So‐Hee
Published: December 2014

Aim

This paper was designed to extend the extant research regarding factors related to nurses' turnover intentions.

Methods

This survey‐based study was based on a path analysis designed to verify a hypothesized causal model involving nurses' role stress, organizational commitment, turnover intentions, and burnout. This study distributed 500 questionnaires to nurses in general hospitals with more than 500 beds located in Seoul, Korea, during 16–30 April 2012.

Results

Role conflict, an underlying factor in role stress, had no significant effect on role stress, but the results showed that role ambiguity reduced organizational commitment. On the other hand, role conflict and role ambiguity increased the level of burnout. Organizational commitment reduced turnover intentions, and burnout increased turnover intentions. Role conflict and role ambiguity had no direct effect on turnover intentions, but they had indirect effects on organizational commitment and burnout.

Conclusion

To reduce nurses' turnover rate, this study recommends developing plans to improve their organizational commitment because it mediates role stress and turnover intention.
Colonialism and Time in Sylvia Townsend Warner'sMr Fortune's Maggot
Authors: Booth Howard J.
Published: December 2014

This article argues for the significance of time to Sylvia Townsend Warner'sMr Fortune's Maggot(1927). It draws on recent work on time, modernism and empire to contest the view that imagining alternatives to western conceptions of time constitutes a fall into primitivism. A reading of the role of time in Warner'sMr Fortune's Maggotis offered, where the concluding paragraphs explore how its “sequel”, “The Salutation”, takes the novel's concern with time further.
Combined next‐generation sequencing and morphology reveal fine‐scale speciation in Crocodile Skinks (Squamata: Scincidae:Tribolonotus)
Authors: Rittmeyer Eric N. , Austin Christopher C.
Published: December 2014

Next‐generation sequencing has vast potential to revolutionize the fields of phylogenetics and population genetics through its ability to collect genomic scale data sets of thousands of orthologous loci. Despite this potential, other types of data (e.g. morphology, ecology) remain important, particularly for studies endeavouring to delimit species. Here, we integrate next‐generation sequencing with morphology to examine divergence between populations ofTribolonotus pseudoponceletion the islands of Buka and Bougainville in the Solomon Archipelago. We used the Ion TorrentPGMto collect over 648 Mbp of sequence data for 12 samples, representing 1526 loci recovered from all samples, and 3342 were recovered from at least six samples. Genetic structure analyses strongly support the distinctiveness of these two populations, and Bayes factor delimitations decisively select speciation between Buka and Bougainville. Principal components and discriminant function analyses reveal concordant morphological divergence. Finally, demographic analyses via diffusion approximation and approximate Bayesian computation prefer a complex model of mid‐Pleistocene divergence with migration, and a later decrease or cessation of migration and population size shift, suggesting a scenario in which migration was enabled by Pleistocene merging of these two islands, and limited when isolated by higher sea levels. Further analysis of four Sanger sequenced loci inIMa2 had limited power to distinguish among models including and excluding migration, but resulted in similar population size and divergence time estimates, although with much broader confidence intervals. This study represents a framework for how next‐generation sequencing and morphological data can be combined and leveraged towards validating putative species and testing demographic scenarios for speciation.
Tissue‐specific gene expression in maize seeds during colonization by Aspergillus flavus and Fusarium verticillioides
Authors: Shu Xiaomei , Livingston David P. , Franks Robert G. , Boston Rebecca S. , Woloshuk Charles P. , Payne Gary A.
Published: December 2014

Aspergillus flavus and Fusarium verticillioides are fungal pathogens that colonize maize kernels and produce the harmful mycotoxins aflatoxin and fumonisin, respectively. Management practice based on potential host resistance to reduce contamination by these mycotoxins has proven difficult, resulting in the need for a better understanding of the infection process by these fungi and the response of maize seeds to infection. In this study, we followed the colonization of seeds by histological methods and the transcriptional changes of two maize defence‐related genes in specific seed tissues by RNA in situ hybridization. Maize kernels were inoculated with either A. flavus or F. verticillioides 21–22 days after pollination, and harvested at 4, 12, 24, 48, 72, 96 and 120 h post‐inoculation. The fungi colonized all tissues of maize seed, but differed in their interactions with aleurone and germ tissues. RNA in situ hybridization showed the induction of the maize pathogenesis‐related protein, maize seed (PRms) gene in the aleurone and scutellum on infection by either fungus. Transcripts of the maize sucrose synthase‐encoding gene, shrunken‐1 (Sh1), were observed in the embryo of non‐infected kernels, but were induced on infection by each fungus in the aleurone and scutellum. By comparing histological and RNA in situ hybridization results from adjacent serial sections, we found that the transcripts of these two genes accumulated in tissue prior to the arrival of the advancing pathogens in the seeds. A knowledge of the patterns of colonization and tissue‐specific gene expression in response to these fungi will be helpful in the development of resistance.
Results of Lumbar Endoscopic Adhesiolysis Using a Radiofrequency Catheter in Patients with Postoperative Fibrosis and Persistent or Recurrent Symptoms After Discectomy
Authors: Pereira Paulo , Severo Milton , Monteiro Pedro , Silva Pedro Alberto , Rebelo Virgínia , Castro‐Lopes José Manuel , Vaz Rui
Published: December 2014

Objective

To evaluate the results of lumbar epiduroscopic adhesiolysis using mechanical methods and a radiofrequency catheter followed by epidural steroid and local anesthetic administration in patients with postoperative fibrosis and persistent or recurrent symptoms.

Study Design

Prospective study.

Methods

Patients with persistent or recurrent low back and/or lower limb pain after lumbar spine surgery, in whom no relevant findings were present on MR images besides epidural scar tissue, were submitted to epiduroscopic adhesiolysis. Patient‐reported outcomes including pain and disability were assessed in predefined time intervals and compared to baseline.

Results

Twenty‐four patients were enrolled. It was possible to elicit the patient's usual pain by probing the epidural scar tissue in all patients. Statistically significant improvement in low back and lower limb pain was observed in all assessment periods up to 12 months. A pain relief over 50% was achieved in 71% of the patients at 1 month, 63% at 3 and 6 months, and 38% at 12 months. Disability scores significantly improved for around 6 months. Mean patient satisfaction rates were 80% at 1 month, 75% at 3 months, 70% at 6 months, and 67% 1 year after intervention. Only 1 transient postprocedural complication was detected.

Conclusion

Endoscopic adhesiolysis is a potentially useful treatment for the relief of chronic intractable low back and lower limb pain in patients with previous lumbar spine surgery and epidural fibrosis. The use of larger volumes of saline during endoscopy and the employment of radiofrequency for the lysis of epidural adhesions are safe procedures, which may provide an additional benefit to the intervention.
Educational and therapeutic behavioral approaches to providing dental care for patients with Autism Spectrum Disorder
Authors: Nelson Travis M. , Sheller Barbara , Friedman Clive S. , Bernier Raphael
Published: December 2014

Purpose

Autism Spectrum Disorder (ASD) is a condition which most dentists will encounter in their practices. Contemporary educational and behavioral approaches may facilitate successful dental care.

Methods

A literature review was conducted for relevant information on dental care for children with ASD.

Results

Educational principles used for children with ASD can be applied in the dental setting. Examples include: parent involvement in identifying strengths, sensitivities, and goal setting; using stories or video modeling in advance of the appointment; dividing dental treatment into sequential components; and modification of the environment to minimize sensory triggers. Patients with ASD are more capable of tolerating procedures that they are familiar with, and therefore should be exposed to new environments and stimuli in small incremental steps.

Conclusions

By taking time to understand children with ASD as individuals and employing principles of learning, clinicians can provide high quality dental care for the majority of patients with ASD.
Have Beauty Ideals Evolved? Reading of Beauty Ideals in Tamil Movies by Malaysian Indian Youths
Authors: Karupiah Premalatha
Published: December 2014

Studies have shown that beauty ideals are often exemplified, transmitted, and maintained through cultural products such as art, literature, and movies. This article analyzes the perception of beauty ideals in Tamil movies by Malaysian Indian youths and beauty ideals in Tamil movies from the 1960s to 2009. There were two stages of data collection. The first stage consisted of in‐depth interviews with 20 female and 20 male students at a public university in Malaysia. They were selected using a purposive sampling method. The next stage involved a content analysis of 25 Tamil movies produced from the 1960s to 2009, selected by means of a stratified sampling technique. The analysis showed that some elements of beauty ideals have evolved in Tamil movies, and these trends were also identified by the participants. The preference for thinness, fairness/whiteness, and youthfulness is prevalent for actresses, but not for male actors. This may be a reflection of sociocultural expectations of contemporary Indian society and the mass consumption of global media. The emphasis on traditional feminine ideals remains obvious in these movies, even though the prominence given to them has decreased over the years. Understanding these changes is important in media literacy and in the design of intervention programs for youth.
Splenic and hepatic ultrasound and cytology in canine lymphoma: effects of findings on stage migration and assessment of prognosis
Authors: Nerschbach V. , Eberle N. , Joetzke A. E. , Hoeinghaus R. , Hungerbuehler S. , Mischke R. , Nolte I. , Betz D.
Published: December 2014

Stage migration is described in humans and dogs as a sequel of using more sensitive diagnostic methods. One hundred eighty‐six dogs with multicentric lymphoma were enrolled with results of conventional staging as well as ultrasonographic and cytological examination of liver and spleen being available. The addition of splenic respective hepatic ultrasound and cytology findings resulted in slightly lower number of dogs classified as having liver and spleen involvement. In dogs with multicentric lymphoma, addition of cytology led to a significant shift of individuals from stageIVto stageIII. Findings of hepatic and splenic ultrasound and cytology exerted no significant influence on complete remission and survival durations in dogs with combination chemotherapy. Staging methodology in canine lymphoma should be redefined, considering that the prognostic significance of splenic and hepatic ultrasound and cytology warrants further investigation.
A Comparison of Techniques to Measure the Wear Flat Area of Conventional and Superabrasive Grinding Wheels
Authors: Puerto Pablo , Kirsch Benjamin , Madariaga Jon , Fernández Raúl , Aurich Jan C. , Gallego Iván
Published: December 2014

Wear of abrasive grains is one of the key issues influencing the grinding process and the resulting workpiece quality. Being able to quantify wheel wear in-process allows parameterization of grinding models that can help assuring part surface integrity. However, one of the main problems in measuring wear of abrasive grains is their small size, which makes this task to be not trivial. In this paper, several measuring techniques are compared in order to determine which one offers the best potential to quantify the wear of conventional and superabrasive grinding wheels. The selected techniques include optical macroscopy, optical microscopy, profilometry, and scanning electron microscopy (SEM). Among other results, direct comparisons of the same exact wear flat area measured with different techniques are shown.
A Pipe Bend Subject to a Uniformly Distributed Radial Force
Authors: Mazzeo Joseph M.
Published: December 2014

The effects of a distributed radial load on an elbow or bend within a piping system, caused by changes in momentum due to fluid flow, can be represented by one or more point loads. Simplified methods result in inaccurate results in some cases. Modeling the bend with multiple nodes and forces increases accuracy. The method presented here will provide accurate results, comparable to breaking up the bend into many nodes and forces. A number of example analyses are presented for comparison with simplified modeling methods and the potential importance of considering momentum change forces in some power piping geometries are discussed.
Application of a Biphasic Actuator in the Design of the CloPeMa Robot Gripper
Authors: Le Loan , Zoppi Matteo , Jilich Michal , Bo Han , Zlatanov Dimiter , Molfino Rezia
Published: December 2014

The paper (a first version of this work was presented in Aug. 2014 at ASME-DETC in Buffalo, NY) describes a novel robot gripper for garment handling. The device has been designed, developed, prototyped, and tested within the CloPeMa European Project creating a robot system for automated manipulation of clothing and other textile items. The gripper has two degrees of freedom (dof) and includes both rigid and flexible elements. A variable-stiffness actuator has been implemented to add controlled compliance in the gripper’s operation allowing the combining of various grasping and manipulation tasks. First, we analyze the specific application-determined task requirements, focusing on the need for adaptive flexibility and the role of compliant elements in the design. The chosen solution is a simple planar mechanism, equipped with one standard and one variable-stiffness actuator. The mechanical design of the gripper, including the hydraulic system used in the biphasic actuator, is outlined, and the control architecture, using sensor feedback, is described.
Improving Techniques in Statically Equivalent Serial Chain Modeling for Center of Mass Estimation
Authors: Li Bingjue , Murray Andrew P. , Myszka David H.
Published: December 2014

Any articulated system of rigid bodies defines a statically equivalent serial chain (SESC). The SESC is a virtual chain that terminates at the center of mass (CoM) of the original system of bodies. An SESC may be generated experimentally without knowing the mass, CoM, or length of each link in the system given that its joint angles and overall CoM may be measured. This paper presents three developments toward recognizing the SESC as a practical modeling technique. Two of the three developments improve utilizing the technique in practical applications where the arrangement of the joints impacts the derivation of the SESC. The final development provides insight into the number of poses needed to create a usable SESC in the presence of data collection errors. First, modifications to a matrix necessary in computing the SESC are proposed, followed by the experimental validation of SESC modeling. Second, the problem of generating an SESC experimentally when the system of bodies includes a mass fixed in the ground frame are presented and a remedy is proposed for humanoid-like systems. Third, an investigation of the error of the experimental SESC versus the number of data readings collected in the presence of errors in joint readings and CoM data is conducted. By conducting the method on three different systems with various levels of data error, a general form of the function for estimating the error of the experimental SESC is proposed.
A Unified Algorithm for Analysis and Simulation of Planar Four-Bar Motions Defined With R- and P-Joints
Authors: Li Xiangyun , Ge Xin , Purwar Anurag , Ge Q. J.
Published: December 2014

This paper presents a single, unified, and efficient algorithm for animating the coupler motions of all four-bar mechanisms formed with revolute (R) and prismatic (P) joints. This is achieved without having to formulate and solve the loop closure equation for each type of four-bar linkages separately. Recently, we developed a unified algorithm for synthesizing various four-bar linkages by mapping planar displacements from Cartesian space to the image space using planar quaternions. Given a set of image points that represent planar displacements, the problem of synthesizing a planar four-bar linkage is reduced to finding a pencil of generalized manifolds (or G-manifolds) that best fit the image points in the least squares sense. In this paper, we show that the same unified formulation for linkage synthesis leads to a unified algorithm for linkage analysis and simulation as well. Both the unified synthesis and analysis algorithms have been implemented on Apple's iOS platform.
Design and Analysis of a Novel Articulated Drive Mechanism for Multifunctional NOTES Robot
Authors: Shen Tao , Nelson Carl A. , Warburton Kevin , Oleynikov Dmitry
Published: December 2014

This paper presents a novel articulated drive mechanism (ADM) for a multifunctional natural orifice transluminal endoscopic surgery (NOTES) robotic manipulator. It consists mainly of three major components including a snakelike linkage, motor housing, and an arm connector. The ADM can articulate into complex shapes for improved access to surgical targets. A connector provides an efficient and convenient modularity for insertion and removal of the robot. Four DC motors guide eight cables to steer the robot. The workspace, cable displacement and force transmission relationships are derived. Experimental results give preliminary validation of the feasibility and capability of the ADM system.
A Cable Based Active Variable Stiffness Module With Decoupled Tension
Authors: Zhou Xiaobo , Jun Seung-kook , Krovi Venkat
Published: December 2014

Variable stiffness modules add significant robustness to mechanical systems during forceful interactions with uncertain environments. Most existing variable stiffness modules tend to be bulky—by virtue of their use of solid components—making them less suitable for mobile applications. In recent times, pretensioned cable-based variable stiffness modules have been proposed to reduce weight. While passive, these modules depend on significant internal tension to provide the desired stiffness—as a consequence, their stiffness modulation capability tends to be limited. In this paper, we present design, analysis, and testing of a cable-based active-variable stiffness module which can achieve large stiffness modulation range with low tension. Controlled changes in structural parameters (independent of cable length actuation) now permit independent modulation of both the desired tension and the perceived stiffness. This capability is now systematically evaluated via simulation as well as on a hardware-in-the-loop experimental setup.
Stress engineering using low oxygen background pressures during Volmer–Weber growth of polycrystalline nickel films
Authors: Yu Hang Z. , Thompson Carl V.
Published: December 2014

A robust strategy for controlling the level of residual stress in polycrystalline films remains elusive, owing to the complex coevolution of the surface, microstructure, and intrinsic stress during Volmer–Weber film growth. Recent improvements in the understanding of stress evolution mechanisms have led to the possibility of engineering the intrinsic stress through the control of thin film growth conditions. Here, the authors demonstrate stress engineering during deposition of polycrystalline Ni films through control of the oxygen partial pressure. The physical mechanisms of stress management during codeposition of nickel and oxygen are investigated using in situ stress measurements and ex situ structural and chemical characterizations. The intrinsic stress in Ni films is affected by grain growth during deposition (which causes a tensile stress) and by Ni adatom trapping at grain boundaries and oxygen incorporation in the Ni lattice (which cause a compressive stress). The authors show direct evidence that a small amount of oxygen suppresses grain growth during deposition. They suggest that the presence of chemisorbed oxygen limits surface diffusion of Ni adatoms, thereby limiting adatom trapping at grain boundaries. The presence of oxygen therefore affects the mechanisms for development of both tensile and compressive stresses, providing a direct method for engineering the residual stress in as-deposited Ni films. Finally, the authors demonstrate a process for evaporative deposition of “zero” stress Ni films by introducing a very low level of background impurities, with the resultant films containing only 1.2 at. % oxygen.
Measurements of ocean bottom low-angle backscattering by single-mode reverberation
Authors: Zeng J. , Zhao W. Y. , Peng D. Y. , Li H. F. , Gao T. F. , Shang E. C.
Published: December 2014

The characteristics of scattering due to interface roughness are usually described by the backscattering matrix for reverberation modeling. The backscattering matrix based on the Bass perturbation theory has significant differences from that based on the empirical scattering rule (Lambert's rule), especially at low grazing angles. In a waveguide environment with a point source, it is very difficult to extract the quantitative characteristics of the backscattering matrix at low grazing angles from the experimental data because of the difficulties in acquiring low-grazing-angle scattering data and separating the scattering data between different modes (grazing angles). In contrast, the use of single-mode excitations as sources in shallow-water waveguides enables acquisition of good quality low-grazing-angle scattering data. In this paper, the characteristics of the backscattering matrix were obtained from different single-mode reverberation experiments in shallow-water. The experiments were carried out at different sites during different seasons off the coasts of China. Model-data comparisons were made and the results showed that at low grazing angles (2°–5°), the backscattering matrices based on the Bass perturbation theory were in good agreement with the experimental data, but the backscattering matrices based on Lambert's rule were not.
Sound pressure distribution within natural and artificial human ear canals: Forward stimulation
Authors: Ravicz Michael E. , Tao Cheng Jeffrey , Rosowski John J.
Published: December 2014

This work is part of a study of the interaction of sound pressure in the ear canal (EC) with tympanic membrane (TM) surface displacement. Sound pressures were measured with 0.5–2 mm spacing at three locations within the shortened natural EC or an artificial EC in human temporal bones: near the TM surface, within the tympanic ring plane, and in a plane transverse to the long axis of the EC. Sound pressure was also measured at 2-mm intervals along the long EC axis. The sound field is described well by the size and direction of planar sound pressure gradients, the location and orientation of standing-wave nodal lines, and the location of longitudinal standing waves along the EC axis. Standing-wave nodal lines perpendicular to the long EC axis are present on the TM surface >11–16 kHz in the natural or artificial EC. The range of sound pressures was larger in the tympanic ring plane than at the TM surface or in the transverse EC plane. Longitudinal standing-wave patterns were stretched. The tympanic-ring sound field is a useful approximation of the TM sound field, and the artificial EC approximates the natural EC.
Acoustic radiation torque on small objects in viscous fluids and connection with viscous dissipation
Authors: Zhang Likun , Marston Philip L.
Published: December 2014

This analysis reports a formula for torque and viscous power dissipation in scattering of orthogonal waves and vortex beams by a small compressible solid sphere in a slightly viscous fluid. The analysis is based on a viscous correction to far-field scattering, together with beam superposition. The analysis revels the relation between the torque and dissipation. The torque in a heavy sphere limit agrees with a prior analysis by Busse and Wang using boundary flow analysis. The results are applicable to arbitrary sound fields with proper phase distribution, and are extended to other small axisymmetric obstacles such as circular disks and cylinders.
Perceptual compensation for the effects of reverberation on consonant identification: Evidence from studies with monaural stimuli
Authors: Beeston Amy V. , Brown Guy J. , Watkins Anthony J.
Published: December 2014

Mounting evidence suggests that listeners perceptually compensate for the adverse effects of reverberation in rooms when listening to speech monaurally. However, it is not clear whether the underlying perceptual mechanism would be at all effective in the high levels of stimulus uncertainty that are present in everyday listening. Three experiments investigated monaural compensation with a consonant identification task in which listeners heard different speech on each trial. Consonant confusions frequently arose when a greater degree of reverberation was added to a test-word than to its surrounding context, but compensation became apparent in conditions where the context reverberation was increased to match that of the test-word; here, the confusions were largely resolved. A second experiment shows that information from the test-word itself can also effect compensation. Finally, the time course of compensation was examined by applying reverberation to a portion of the preceding context; consonant identification improves as this portion increases in duration. These findings indicate a monaural compensation mechanism that is likely to be effective in everyday listening, allowing listeners to recalibrate as their reverberant environment changes.
The interaction of lexical and phrasal prosody in whispered speech
Authors: Heeren W. F. L. , van Heuven V. J.
Published: December 2014

The production and perception of Dutch whispered boundary tones, i.e., phrasal prosody, was investigated as a function of characteristics of the tone-bearing word, i.e., lexical prosody. More specifically, the disyllabic tone-bearing word also carried a pitch accent, either on the same syllable as the boundary tone (clash condition), or on the directly adjacent syllable (no clash condition). In a statement/question classification task listeners showed moderate, but above-chance performance for both conditions in whisper, which, however, was much worse as well as slower than in normal speech. The syllabic rhymes of speakers’ productions were investigated for acoustic correlates of boundary tones. Results showed mainly secondary cues to intonation, that is, cues that are present in whisper as in normal speech, but minimal compensatory cues, which would reflect speakers’ efforts to enhance their whispered speech signal in some way. This suggests that multiple prosodic events in close proximity are challenging to perceive and produce in whispered speech. A moderate increase in classification performance was found when that acoustic cue was enhanced that whispering speakers seemed to employ in a compensatory way: changing the spectral tilt of the utterance-final syllable improved perception of especially the poorer speakers and of intonation on stressed syllables.
Forward scattering detection of a submerged object by a vertical hydrophone array
Authors: Lei Bo , Yang Kunde , Ma Yuanliang
Published: December 2014

When an object crosses a source–receiver line, the resulting weak acoustic field aberration is often overwhelmed by a strong direct blast. In this study, a lake experiment with a vertical receiver array spanning the water column was designed and conducted with a 10 kHz pulse. The study aimed to detect the aberration caused by forward scattering from an intercepting submerged object. Although such aberration could be directly observed, it varies by only 3 dB, at most, around the direct blast. Hence, the vertical hydrophone array was subjected to time-delay beamforming, and a principal component analysis was conducted on the stable portion of the beam output. The second principal component was extracted from the horizontally directed beam output waveform at the vertical receiver array. The invariant direct blast component was reduced after analysis, and the field aberration caused by forward scattering of the submerged object was amplified by up to 10 dB above the background acoustic field.
Complex rheological behaviors of loach (Misgurnus anguillicaudatus) skin mucus
Authors: Wang Xiang , Su Heng , Lv Weiyang , Du Miao , Song Yihu , Zheng Qiang
Published: December 2014

The functions and structures of biological mucus are closely linked to rheology. In this article, the skin mucus of loach (Misgurnus anguillicaudatus) was proved to be a weak hydrogel susceptible to shear rate, time, and history, exhibiting: (i) Two-region breakdown of its gel structure during oscillatory strain sweep; (ii) rate-dependent thickening followed by three-region thinning with increased shear rate, and straight thinning with decreased shear rate; and (iii) time-dependent rheopexy at low shear rates, and thixotropy at high shear rates. An interesting correlation between the shear rate- and time-dependent rheological behaviors was also revealed, i.e., the rheopexy-thixotropy transition coincided with the first-second shear thinning region transition. Apart from rheology, a structure of colloidal network was observed in loach skin mucus using transmission electron microscopy. The complex rheology was speculated to result from inter- and intracolloid structural alterations. The unique rheology associated with the colloidal network structure, which has never been previously reported in vertebrate mucus, may play a key role in the functions (e.g., flow, reannealing, lubrication, and barrier) of the mucus.
Joint Torques and Patellofemoral Force During Single-Leg Assisted and Unassisted Cycling
Authors: Bini Rodrigo R. , Jacques Tiago C. , Vaz Marco A.
Published: December 2014

Context:

Unassisted single-leg cycling should be replaced by assisted single-leg cycling, given that this last approach has potential to mimic joint kinetics and kinematics from double-leg cycling. However, there is need to test if assisting devices during pedaling effectively replicate joint forces and torque from double-leg cycling.

Objectives:

To compare double-leg, single-leg assisted, and unassisted cycling in terms of lower-limb kinetics and kinematics.

Design:

Cross-sectional crossover.

Setting:

Laboratory.

Participants:

14 healthy nonathletes.

Interventions:

Two double-leg cycling trials (240 ± 23 W) and 2 single-leg trials (120 ± 11 W) at 90 rpm were performed for 2 min using a bicycle attached to a cycle trainer. Measurements of pedal force and joint kinematics of participants’ right lower limb were performed during double- and single-leg trials. For the single-leg assisted trial, a custom-made adaptor was used to attach 10 kg of weight to the contralateral crank.

Main Outcome Measures:

Peak hip, knee, and ankle torques (flexors and extensors) along with knee-flexion angle and peak patellofemoral compressive force.

Results:

Reduced peak hip-extensor torque (10%) and increased peak knee-flexor torque (157%) were observed at the single-leg assisted cycling compared with the double-leg cycling. No differences were found for peak patellofemoral compressive force or knee-flexion angle comparing double-leg with single-leg assisted cycling. However, single-leg unassisted cycling resulted in larger peak patellofemoral compressive force (28%) and lower knee-flexion angle (3%) than double-leg cycling.

Conclusions:

These results suggest that although single-leg assisted cycling differs for joint torques, it replicates knee loads from double-leg cycling.
Time-resolved serial crystallography captures high-resolution intermediates of photoactive yellow protein
Authors: Tenboer Jason , Basu Shibom , Zatsepin Nadia , Pande Kanupriya , Milathianaki Despina , Frank Matthias , Hunter Mark , Boutet Sébastien , Williams Garth J. , Koglin Jason E. , Oberthuer Dominik , Heymann Michael , Kupitz Christopher , Conrad Chelsie , Coe Jesse , Roy-Chowdhury Shatabdi , Weierstall Uwe , James Daniel , Wang Dingjie , Grant Thomas , Barty Anton , Yefanov Oleksandr , Scales Jennifer , Gati Cornelius , Seuring Carolin , Srajer Vukica , Henning Robert , Schwander Peter , Fromme Raimund , Ourmazd Abbas , Moffat Keith , Van Thor Jasper J. , Spence John C. H. , Fromme Petra , Chapman Henry N. , Schmidt Marius
Published: December 2014

Serial femtosecond crystallography using ultrashort pulses from x-ray free electron lasers (XFELs) enables studies of the light-triggered dynamics of biomolecules. We used microcrystals of photoactive yellow protein (a bacterial blue light photoreceptor) as a model system and obtained high-resolution, time-resolved difference electron density maps of excellent quality with strong features; these allowed the determination of structures of reaction intermediates to a resolution of 1.6 angstroms. Our results open the way to the study of reversible and nonreversible biological reactions on time scales as short as femtoseconds under conditions that maximize the extent of reaction initiation throughout the crystal.
Coherent changes of southeastern equatorial and northern African rainfall during the last deglaciation
Authors: Otto-Bliesner Bette L. , Russell James M. , Clark Peter U. , Liu Zhengyu , Overpeck Jonathan T. , Konecky Bronwen , deMenocal Peter , Nicholson Sharon E. , He Feng , Lu Zhengyao
Published: December 2014

During the last deglaciation, wetter conditions developed abruptly ~14,700 years ago in southeastern equatorial and northern Africa and continued into the Holocene. Explaining the abrupt onset and hemispheric coherence of this early African Humid Period is challenging due to opposing seasonal insolation patterns. In this work, we use a transient simulation with a climate model that provides a mechanistic understanding of deglacial tropical African precipitation changes. Our results show that meltwater-induced reduction in the Atlantic meridional overturning circulation (AMOC) during the early deglaciation suppressed precipitation in both regions. Once the AMOC reestablished, wetter conditions developed north of the equator in response to high summer insolation and increasing greenhouse gas (GHG) concentrations, whereas wetter conditions south of the equator were a response primarily to the GHG increase.
Using and improving the social cost of carbon
Authors: Pizer William , Adler Matthew , Aldy Joseph , Anthoff David , Cropper Maureen , Gillingham Kenneth , Greenstone Michael , Murray Brian , Newell Richard , Richels Richard , Rowell Arden , Waldhoff Stephanie , Wiener Jonathan
Published: December 2014

Regular, institutionalized updating and review are essential
Driving the Earth machine?
Authors: Anderson Don L. , King Scott D.
Published: December 2014

The region of the mantle directly below the tectonic plates plays a key role in mantle flow and volcanism
Untangling the tumor microenvironment:Illuminating the complex interactions and functions of immune cells
Authors: Rodig Scott J. , Stack Edward C.
Published: December 2014

Certain antibody therapies have demonstrated the potential for directing a patient's own immune system against tumors. Further advances in this area will depend upon a detailed understanding of the tumor microenvironment and characterization of the location and status of immune cells and their interaction with tumor cells. This will require methods that provide phenotyping of immune and cancer cells combined with information about their spatial relationship in tumor regions. Additionally, a deeper understanding of the signaling cascades active in immune recognition of cancers is crucial. During this webinar, we will discuss the bringing together of multiplexed fluorescent immunohistochemistry, advanced microscopy techniques, and bioinformatics, and how these are now enabling new insights into cancer biology and immunology.
The measure of research merit
Authors: McNutt Marcia
Published: December 2014

Each year, $1.4 trillion are invested in research by governments, foundations, and corporations. Hundreds if not thousands of high-profile prizes and medals are awarded to the best researchers, boosting their careers. Therefore, establishing a reliable predictor of future performance is a trillion-dollar matter. Last month, the Alexander von Humboldt Foundation convened an international assembly of leaders in academia, research management, and policy to discuss “Beyond Bibliometrics: Identifying the Best.” Current assessment is largely based on counting publications, counting citations, taking note of the impact factor of the journals where researchers publish, and derivatives of these such as the h-index. These approaches were severely criticized for numerous reasons, with shortcomings particularly apparent when assessing young scientists for prestigious, interdisciplinary awards. It is time to develop more appropriate measures and to use the scientific method itself to help in this endeavor.