bluuebunny/crossref_metadata_2025 huggingface dataset:
Adhesion in flexible organic and hybrid organic/inorganic light emitting device and solar cells
Authors: Yu D. , Oyewole O. K. , Kwabi D. , Tong T. , Anye V. C. , Asare J. , Rwenyagila E. , Fashina A. , Akogwu O. , Du J. , Soboyejo W. O.
Published: August 2014

This paper presents the results of an experimental study of the adhesion between bi-material pairs that are relevant to organic light emitting devices, hybrid organic/inorganic light emitting devices, organic bulk heterojunction solar cells, and hybrid organic/inorganic solar cells on flexible substrates. Adhesion between the possible bi-material pairs is measured using force microscopy (AFM) techniques. These include: interfaces that are relevant to organic light emitting devices, hybrid organic/inorganic light emitting devices, bulk heterojunction solar cells, and hybrid combinations of titanium dioxide (TiO2) and poly(3-hexylthiophene). The results of AFM measurements are incorporated into the Derjaguin-Muller-Toporov model for the determination of adhesion energies. The implications of the results are then discussed for the design of robust organic and hybrid organic/inorganic electronic devices.
Dynamics of step-emulsification: From a single to a collection of emulsion droplet generators
Authors: Mittal Nitesh , Cohen Céline , Bibette Jérôme , Bremond Nicolas
Published: August 2014

Microfluidics has proven to be an efficient tool for making fine and calibrated emulsion droplets. The parallelization of drop makers is required for producing large amounts. Here, we investigate the generation of emulsion drops along a series of shallow microchannels emerging in a deep one, in other words the step-emulsification process. The dynamics of a single drop maker is first characterized as a function of interfacial tension and viscosities of both phases. The characteristic time scale of drop formation, namely, the necking time that finally sets drop size, is shown to be principally governed by the outer phase viscosity to interfacial tension ratio with a minor correction linked to the viscosity ratio. The step emulsification process experiences a transition of fragmentation regime where both the necking time and drop size suddenly raise. This transition, that corresponds to a critical period of drop formation and thus defines a maximum production rate of small droplets, is observed to be ruled by the viscosity ratio of the two phases. When drops are produced along an array of microchannels with a cross flow of the continuous phase, a configuration comparable to a one-dimensional membrane having rectangular pores, a drop boundary layer develops along the drop generators. In the small drop regime, the local dynamics of drop formation is shown to be independent on the emulsion cross flow. Moreover, we note that the development of the drop boundary layer is even beneficial to homogenize drop size along the production line. On the other hand, in the large drop regime, drop collision can trigger fragmentation and thus lead to size polydispersity.
Design and experiment performances of an inchworm type rotary actuator
Authors: Li Jianping , Zhao Hongwei , Shao Mingkun , Zhou Xiaoqin , Huang Hu , Fan Zunqiang
Published: August 2014

A piezo-driven rotary actuator by means of inchworm principle is proposed in this paper. Six piezo-stacks and flexure hinges are used to realize large rotation ranges with high accuracy both in the forward and backward motions. Four right-angle flexure hinges and two right-circular flexure hinges are applied in the stator. The motion principle and theoretical analysis of the designed actuator are discussed. In order to investigate the working characteristics, a prototype actuator was manufactured and a series of experiment tests were carried out. The test results indicate that the maximum rotation velocity is 71 300 μrad/s; the maximum output torque is 19.6 N mm. The experiment results confirm that the designed actuator can obtain large rotation motion ranges with relatively high output torques and different rotation speeds on the condition of different driving voltages and frequencies.
Single line-of-sight dual energy backlighter for mix width experiments
Authors: Baker K. L. , Glendinning S. G. , Guymer T. M. , Martinez D. , Moore A. S. , Dittrich T. R. , MacLaren S. A. , Felker S. , Seugling R. , Doane D. , Wallace R. , Whiting N. , Sorce C.
Published: August 2014

We present a diagnostic technique used to spatially multiplex two x-ray radiographs of an object onto a detector along a single line-of-sight. This technique uses a thin, <2 μm, cosputtered backlighter target to simultaneously produce both Ni and Zn Heα emission. A Ni picket fence filter, 500 μm wide bars and troughs, is then placed in front of the detector to pass only the Ni Heα emission in the bar region and both energies in the trough region thereby spatially multiplexing the two radiographs on a single image. Initial experimental results testing the backlighter spectrum are presented along with simulated images showing the calculated radiographic images though the nickel picket fence filter which are used to measure the mix width in an accelerated nickel foam.
Magneto-optical spectrum analyzer
Authors: Helsen M. , Gangwar A. , Vansteenkiste A. , Van Waeyenberge B.
Published: August 2014

We present a method for the investigation of gigahertz magnetization dynamics of single magnetic nano elements. By combining a frequency domain approach with a micro focus Kerr effect detection, a high sensitivity to magnetization dynamics with submicron spatial resolution is achieved. It allows spectra of single nanostructures to be recorded. Results on the uniform precession in soft magnetic platelets are presented.
Epitaxial growth of large area single-crystalline few-layer MoS2 with high space charge mobility of 192 cm2 V−1 s−1
Authors: Ma Lu , Nath Digbijoy N. , Lee Edwin W. , Lee Choong Hee , Yu Mingzhe , Arehart Aaron , Rajan Siddharth , Wu Yiying
Published: August 2014

We report on the vapor-solid growth of single crystalline few-layer MoS2 films on (0001)-oriented sapphire with excellent structural and electrical properties over centimeter length scale. High-resolution X-ray diffraction scans indicated that the films had good out-of-plane ordering and epitaxial registry. A carrier density of ∼2 × 1011 cm−2 and a room temperature mobility of 192 cm2/Vs were extracted from space-charge limited transport regime in the films. The electron mobility was found to exhibit in-plane anisotropy with a ratio of ∼1.8. Theoretical estimates of the temperature-dependent electron mobility including optical phonon, acoustic deformation potential, and remote ionized impurity scattering were found to satisfactorily match the measured data. The synthesis approach reported here demonstrates the feasibility of device quality few-layer MoS2 films with excellent uniformity and high quality.
Continuous-time control of alternans in long Purkinje fibers
Authors: Garzón Alejandro , Grigoriev Roman O. , Fenton Flavio H.
Published: August 2014

Alternans—an arrhythmic response of cardiac tissue to periodic pacing—often serves as a precursor to a more dangerous, and potentially lethal, state of fibrillation. Suppression of alternans using feedback control may be a plausible method to prevent fibrillation. Several approaches based on impulsive control have been proposed previously, where feedback is applied for a brief instance of time during each pacing interval. This paper presents a continuous-time approach, where feedback current is applied at all times, which is capable of suppressing alternans in fibers of significantly greater length (up to at least 4 cm), compared with impulsive control (less than 1 cm), and for a wide range of pacing cycle lengths.
Structural investigations on Co3-xMnxTeO6; (0 < x ≤ 2); High temperature ferromagnetism and enhanced low temperature anti-ferromagnetism
Authors: Singh Harishchandra , Sinha A. K. , Ghosh Haranath , Singh M. N. , Rajput Parasmani , Prajapat C. L. , Singh M. R. , Ravikumar G.
Published: August 2014

In the quest of materials with high temperature ferromagnetism and low temperature anti-ferromagnetism, we prepare Co3-xMnxTeO6; (0 < x ≤ 2) solid solutions. Room temperature structural investigations on these solid solutions as a function of Mn concentration using Synchrotron X-ray diffraction (SXRD) and X-ray absorption near edge structure measurements in corroboration with magnetism are presented. Phase diagram obtained from Rietveld Refinement on SXRD data as a function of Mn concentration indicates doping disproportionate mixing of both monoclinic (C2/c) and rhombohedral (R 3¯) structure for x < 0.5, while only R 3¯ structure for x ≥ 0.5. Further, it shows increase in both lattice parameters as well as average transition metal-oxygen (Co/Mn-O) bond lengths for x ≥ 0.5. Co and Mn K-edge XANES spectra reveal that both Co and Mn are in mixed oxidation state, Co2+/Mn2+ and Co3+/Mn3+. Relative ratios of Co3+/Co2+ and Mn3+/Mn2+ obtained using Linear combination fit decrease with increasing x (for x ≥ 0.5). These structural and spectroscopic evidences are used to provide possible interpretation of the observed paramagnetic to ferromagnetic transition at around 185 K followed by an enhanced antiferromagnetic transition ∼45 K for x = 0.5.
Effect of geometrical torsion on the rectification properties of diblock conjugated molecular diodes
Authors: Cui Bin , Zhao Wenkai , Wang Hui , Zhao Jingfen , Zhao He , Li Dongmei , Jiang Xiaohui , Zhao Peng , Liu Desheng
Published: August 2014

We model several Au/conjugated molecule/Au junctions in the presence of molecular geometrical torsions. A rectification ratio of around 10 in the twisty diphenyldipyrimidinyl system is obtained, which is in good agreement with experiment. Deeper insight into the rectification mechanism of the conjugated molecular diodes is presented on the basis of simulations in a set of simpler but similar junctions. The rectification effect (the ratio) is significantly improved with increasing the molecular twist, while the conductance is reduced accordingly. Our results suggest that the rectification can be enhanced by the geometrical-torsion-induced reduction in the conjugation length of organic molecules.
Microstructures, dielectric, and piezoelectric properties of W/Cr co-doped Bi4Ti3O12 ceramics
Authors: Chen Yu , Liang Dayun , Wang Qingyuan , Zhu Jianguo
Published: August 2014

W/Cr co-doped Bi4Ti3O12 (BTWC) ceramics {Bi4Ti3−xWxO12 + x + 0.2 wt. % Cr2O3 (x = 0–0.1)} with a high piezoelectricity were prepared by a conventional ceramic process, and effects of W/Cr dopant on the microstructures, dielectric, and piezoelectric properties of ceramics were explored. It is found that W6+ modified the grain morphology and size of ceramics, promoting the forming of the regular schistose grains with a size of ∼10 μm in the ceramic at x = 0.05. BTWC ceramics showed a continuous decrease in Tc and a gradual increase in εr with the increasing W doping content. While the hard-doping of Cr2O3 decreased, the TKε and tan δ of ceramics available. All the ceramics keep the nature of first-order transition and displacive ferroelectrics. The d33 and kp of BTWC ceramics were remarkably improved by the soft-doping of W6+. Excellent electrical properties (e.g., Tc = 638 °C, εr = 146, tan δ = 0.56%, TKε (500 °C) = 1.30 × 10−3/ °C, τ (500 °C) = 4.08 × 10−5 s, d33 = 28 pC/N, and kp = 6.17%) have been achieved in Bi4Ti2.95W0.05O12.05 + 0.2 wt. % Cr2O3 ceramic. Such a material can be a promising candidate for high-temperature piezoelectric applications.
Decentralized coordinated neural control of doubly fed induction generator based wind farm for power system stability support
Authors: Niu Yuguang , Li Xiaoming , Lin Zhongwei
Published: August 2014

This paper aims at improving the excitation control system for the doubly fed induction generator-based wind farm (WF). The proposed decentralized coordinated neural control is consisted of two controllers, i.e., a multiple model predictive controller (MPC) and an artificial neural network (ANN) controller. The MPC is based on the interaction measurement model and designed to guarantee the performance of system-wide optimization around the chosen operating points, while the ANN controller is used to calculate the weights of MPC controllers and trained to guarantee the control performance over the full operating region. The proposed control strategy allows to reduce the computational cost, and at the same time to take advantage of the distributed nature of the power system. Moreover, a simple, generic hybrid power system is used to demonstrate transient stability contributions. The problems of large-scale WF integration and its impact on transient stabilities of power systems are discussed through the eigenvalue analysis and time domain simulation. The results show that system damping and transient stability of hybrid power system are considerably improved.
Spin-torque diode radio-frequency detector with voltage tuned resonance
Authors: Skowroński Witold , Frankowski Marek , Wrona Jerzy , Stobiecki Tomasz , Ogrodnik Piotr , Barnaś Józef
Published: August 2014

We report on a voltage-tunable radio-frequency (RF) detector based on a magnetic tunnel junction (MTJ). The spin-torque diode effect is used to excite and/or detect RF oscillations in the magnetic free layer of the MTJ. In order to reduce the overall in-plane magnetic anisotropy of the free layer, we take advantage of the perpendicular magnetic anisotropy at the interface between ferromagnetic and insulating layers. The applied bias voltage is shown to have a significant influence on the magnetic anisotropy, and thus on the resonance frequency of the device. This influence also depends on the voltage polarity. The obtained results are accounted for in terms of the interplay of spin-transfer-torque and voltage-controlled magnetic anisotropy effects.
Power quality improvement in solar photovoltaic system to reduce harmonic distortions using intelligent techniques
Authors: Alexander S. Albert , Manigandan T.
Published: August 2014

This paper presents the harmonic elimination in a solar fed cascaded fifteen level inverter supplied with varying input sources from solar Photo Voltaic's (PV) using the modern intelligent techniques such as Artificial Neural Networks (ANNs), Genetic Algorithm (GA) and Particle Swarm Optimization (PSO). In ANN based approach the harmonic equations are solved and switching angles are obtained such that the fundamental is kept constant and lower order harmonics are minimized or eliminated. The data set with varying input voltages and switching angles are trained with ANN. The trained network is integrated with solar PV system to reduce the harmonic distortions. Similarly the objective function for the proposed methodology is formulated and corresponding operations are performed with respect to optimization techniques (GA and PSO) to obtain the optimal switching angles required for the inverter switches. The modeling of solar panel is developed which serves as the input in simulation. The results show that ANN based method provide a significant improvement of power quality with respect to the reduction of Total Harmonic Distortion when compared to the other techniques. A 3 kWp solar PV plant with a fifteen level inverter incorporated with ANN based technique is implemented in hardware to show the effectiveness of the proposed method.
Electronic Bloch oscillation in bilayer graphene gradient superlattices
Authors: Cheng Hemeng , Li Changan , Ma Tianxing , Wang Li-Gang , Song Yun , Lin Hai-Qing
Published: August 2014

We investigate the electronic Bloch oscillation in bilayer graphene gradient superlattices using transfer matrix method. By introducing two kinds of gradient potentials of square barriers along electrons propagation direction, we find that Bloch oscillations up to terahertz can occur. Wannier-Stark ladders, as the counterpart of Bloch oscillation, are obtained as a series of equidistant transmission peaks, and the localization of the electronic wave function is also signature of Bloch oscillation. Furthermore, the period of Bloch oscillation decreases linearly with increasing gradient of barrier potentials.
Does Deindustrialisation Cause Social Polarisation in Global Cities?
Authors: Crankshaw Owen , Borel-Saladin Jacqueline
Published: August 2014

The social polarisation hypothesis argues that deindustrialisation causes the polarisation of the occupational structure, which in turn causes the income polarisation of the employed workforce of global cities. A central argument is that social polarisation occurs because the service sector is more polarised in occupational and income terms than the manufacturing sector that it replaces. However, the results of many studies suggest that deindustrialisation has not resulted in social polarisation. Instead, deindustrialisation has produced a professionalised occupational structure alongside high levels of unemployment. The results of this study of the Johannesburg region confirm that deindustrialisation results in professionalisation rather than polarisation. We then proceed to examine this outcome by analysing the statistical relationship between economic restructuring and the changing occupational structure. Our results suggest that changes in the overall occupational structure were caused by changes within each economic sector rather than by the growth of service sector employment and the decline of manufacturing sector employment.
Fear and Loathing in the San Juan Islands: Endangered Orcas and the Legitimacy of Environmental Law
Authors: Herbert Steve
Published: August 2014

Although a healthy environment is generally recognized as an important public good, environmental regulation often meets significant opposition. The legitimacy of environmental law is thus very much an uncertain political project, as is evident in many struggles over environmental protection. I use and extend literatures on legal consciousness, legal geographies, and environmental regulation to analyze a controversy that emerged over efforts to regulate vessels in the presence of endangered orca whales in the Pacific Northwest. I suggest that a significant component of the opposition to these regulations stemmed from a widespread distrust and fear of the federal government. This distrust and fear were sharply accentuated by the fact that the regulations were to be imposed on the space of the sea, an area commonly viewed as best left unregulated or as deeply unregulatable. Given the arguable need for robust state action to protect the environment, on the sea as well as on land, these ambient fears are significant, and pose notable obstacles to the legitimacy of environmental law.
Knowledge Sourcing, Knowledge Bases, and the Spatial Organisation of Car Design
Authors: van Tuijl Erwin , Carvalho Luís
Published: August 2014

This paper analyses the geographical implications of having different types of knowledge bases—synthetic and symbolic—involved in one single but complex innovation process: car design. To do so, we investigated three contrasting car design strategies (Audi, Renault, and SAIC-GM) with the aim of exploring empirical regularities and the reasons underlying the links between knowledge bases, knowledge sourcing mechanisms, and resulting spatial configurations. Evidence suggests that when the synthetic knowledge base is dominant, formal collaboration and mobility are prime knowledge sourcing mechanisms. Moreover, knowledge creation and exchange is likely to occur between actors permanently located within the same region or through the temporary colocation of globally spread innovation partners. On the other hand, when symbolic knowledge is dominant, mobility, monitoring, and buzz turn to be the most relevant sourcing mechanisms, and knowledge creation and exchange are likely to occur within a more strictly local dimension (eg, in cities), through temporary colocation configurations (eg, presence in fairs and via temporary staff exchange), and by global scanning of competitors and trends.
University Challenges: Negotiating Secularism and Religiosity in Higher Education Institutions
Authors: Jones Rhys Dafydd
Published: August 2014

While geographers' examinations of religion and secularism have emphasized identity politics of faith in everyday life, little attention has been paid to intuitional politics and historical approaches to religious accommodation. Such historical approaches are critical to understanding contemporary religious service provision outside metropolitan areas, where minority faiths typically depend on the ‘goodwill’ of institutions. This paper examines campaigns to establish a mosque at a secular British university in the 1980s and 1990s, highlighting the different visions for the project: a sacred space for communal worship and a resource to attract lucrative international students. It highlights how notions of hospitality towards international students were emphasized to circumvent concerns that the university's secular status would be damaged by such a development. The paper concludes by considering questions on the role of hospitality in accommodating diversity.
Protein Immobilization in Metal–Organic Frameworks by Covalent Binding
Authors: Wang Xuan , Makal Tegan A. , Zhou Hong-Cai
Published: August 2014

Metal–organic frameworks (MOFs), possessing a well defined system of pores, demonstrate extensive potential serving as a platform in biological catalysis. Successful immobilization of enzymes in a MOF system retains the enzymatic activity, renders the active site more accessible to the substrate, and promises recyclability for reuse, and solvent adaptability in a broad range of working conditions. This highlight describes enzyme immobilization on MOFs via covalent binding and its significance.
Light-stimulated heat tolerance in leaves of two neotropical tree species, Ficus insipida and Calophyllum longifolium
Authors: Krause G. Heinrich , Winter Klaus , Krause Barbara , Virgo Aurelio
Published: August 2014

Previous heat tolerance tests of higher plants have been mostly performed with darkened leaves. However, under natural conditions, high leaf temperatures usually occur during periods of high solar radiation. In this study, we demonstrate small but significant increases in the heat tolerance of illuminated leaves. Leaf disks of mature sun leaves from two neotropical tree species, Ficus insipida Willd. and Calophyllum longifolium Willd., were subjected to 15 min of heat treatment in the light (500 µmol photons m–2 s–1) and in the dark. Tissue temperatures were controlled by floating the disks on the surface of a water bath. PSII activity was determined 24 h and 48 h after heating using chlorophyll a fluorescence. Permanent tissue damage was assessed visually during long-term storage of leaf sections under dim light. In comparison to heat treatments in the dark, the critical temperature (T50) causing a 50% decline of the fluorescence ratio Fv/Fm was increased by ~1°C (from ~52.5°C to ~53.5°C) in the light. Moreover, illumination reduced the decline of Fv/Fm as temperatures approached T50. Visible tissue damage was reduced following heat treatment in the light. Experiments with attached leaves of seedlings exposed to increasing temperatures in a gas exchange cuvette also showed a positive effect of light on heat tolerance.
Phospholipase A2regulates eicosanoid class switching during inflammasome activation
Authors: Norris Paul C. , Gosselin David , Reichart Donna , Glass Christopher K. , Dennis Edward A.
Published: August 2014

Significance

Group IVA cytosolic phospholipase A2(GIVA cPLA2) is widely viewed as the primary enzyme responsible for inflammatory arachidonic acid (AA) release and with high specificity. Our results demonstrate dual, phase-specific release of AA and 15-hydroxyeicosatetraenoic (15-HETE) acid by GIVA cPLA2in primary and immortalized macrophages during a receptor-mediated program required for complete inflammatory commitment. These dual actions by GIVA cPLA2were necessary for biosynthesis of proresolving lipoxins, providing a unique, upstream example of an enzyme linked to both the initiation and resolution of inflammation. Further, our results demonstrate a single-cell mechanism of lipoxin synthesis that is more efficient than the established transcellular biosynthetic mechanisms, underscoring the importance of enzyme coupling and the possibility of proresolution therapies at the membrane level.
Interlamellar CA1 network in the hippocampus
Authors: Yang Sunggu , Yang Sungchil , Moreira Thais , Hoffman Gloria , Carlson Greg C. , Bender Kevin J. , Alger Bradley E. , Tang Cha-Min
Published: August 2014

Significance

It has generally been thought that CA1 cells form only negligible connections with each other along the longitudinal axis of the hippocampus. But if CA1 cells were interconnected in an effective autoassociational network, this information would add a critical new dimension to our understanding of cellular processing within this structure. Here, we report the existence of a well-organized, longitudinally projecting synaptic network among CA1 pyramidal neurons. We further show that synapses of this network are capable of supporting synaptic plasticity, including long-term potentiation, and a short-term memory mechanism called “dendritic hold and read.” These observations will contribute to the construction of more realistic models of hippocampal information processing in behavior, memory, and other cognitive functions.
Immunolocalization of skeletal matrix proteins in tissue and mineral of the coralStylophora pistillata
Authors: Mass Tali , Drake Jeana L. , Peters Esther C. , Jiang Wenge , Falkowski Paul G.
Published: August 2014

Significance

Although various aspects of biomineralization in corals have been studied for decades, the basic mechanism responsible for the precipitation of the aragonite skeleton remains enigmatic. To address this issue, we used antibodies against key biomineralization proteins derived from the common zooxanthellate coralStylophora pistillatato elucidate the spatial arrangement of specific skeletal matrix proteins in the skeleton and in the animal tissue. To our knowledge, our results reveal for the first time that the biomineral is produced in discrete nanoscale packages in which the secreted organic matrices remain entrapped within the crystalline units whose growth they control, leading to the formation of highly ordered, microscopic, heterologous structures, which are aggregated to form a macroscopic skeleton.
Targeted gene knockout in chickens mediated by TALENs
Authors: Park Tae Sub , Lee Hong Jo , Kim Ki Hyun , Kim Jin-Soo , Han Jae Yong
Published: August 2014

Significance

Targeted gene knockout by editing specific loci in genome has revolutionized the field of functional genomics. Transcription activator-like effector nucleases (TALENs) are representative next-generation platforms for customized genomic editing in transgenic animals, as well as cultured cells in vitro. In this study, in combination with chicken primordial germ cell line with germ-line transmission capacity, we generated the
ovalbumin
gene knockout chickens by TALEN-mediated gene targeting. Our results extended the application of state-of-the-art TALEN technology from experimental animals to farm animals. As TALEN-mediated knockout chickens are genetically modified but nontransgenic, without genomic integration of any exogenous transgenes, specific genomic editing with TALENs could expedite the generation of genetically engineered chickens for agriculturally practical applications as well as for model animals.
Refilling drug delivery depots through the blood
Authors: Brudno Yevgeny , Silva Eduardo A. , Kearney Cathal J. , Lewin Sarah A. , Miller Alex , Martinick Kathleen D. , Aizenberg Michael , Mooney David J.
Published: August 2014

Significance

Drug delivery depots used in the clinic today are single use, with no ability to refill once exhausted of drug. Our system exploits nucleic acid complementarity to refill drug-delivering depots through the blood. The utility of this approach is demonstrated by its ability to inhibit tumor growth to a greater extent than strategies that rely on enhanced permeability and retention alone. We anticipate our approach will be directly applicable to therapies for many diseases, including cancer, wound healing, and inflammation, and for drug reloading of vascular grafts and stents.
Assessment of interaction quality in mobile robotic telepresence
Authors: Kristoffersson Annica , Coradeschi Silvia , Loutfi Amy , Severinson-Eklundh Kerstin
Published: August 2014

In this paper, we focus on spatial formations when interacting via mobile robotic telepresence (MRP) systems. Previous research has found that those who used a MRP system to make a remote visit (pilot users) tended to use different spatial formations from what is typical in human-human interaction. In this paper, we present the results of a study where a pilot user interacted with ten elderly via a MRP system. Intentional deviations from known accepted spatial formations were made in order to study their effect on interaction quality from the local user perspective. Using a retrospective interviews technique, the elderly commented on the interaction and confirmed the importance of adhering to acceptable spatial configurations. The results show that there is a mismatch between pilot user behaviour and local user preference and that it is important to evaluate a MRP system from two perspectives, the pilot user’s and the local user’s. Keywords: F-formations; Mobile Robotic Telepresence; MRP systems; Quality of Interaction; Retrospective Interview; Spatial Formations; Spatial Configurations
Antibiotic Prescribing Practices in a Multicenter Cohort of Patients Hospitalized for Acute Bacterial Skin and Skin Structure Infection
Authors: Jenkins Timothy C. , Knepper Bryan C. , Moore S. Jason , O’Leary Sean T. , Caldwell Brooke , Saveli Carla C. , Pawlowski Sean W. , Perlman Daniel M. , McCollister Bruce D. , Burman William J.
Published: August 2014

Objective.

Hospitalizations for acute bacterial skin and skin structure infection (ABSSSI) are common. Optimizing antibiotic use for ABSSSIs requires an understanding of current management. The objective of this study was to evaluate antibiotic prescribing practices and factors affecting prescribing in a diverse group of hospitals

Design.

Multicenter, retrospective cohort study.

Setting.

Seven community and academic hospitals.

Methods.

Children and adults hospitalized between June 2010 and May 2012 for cellulitis, wound infection, or cutaneous abscess were eligible. The primary endpoint was a composite of 2 prescribing practices representing potentially avoidable antibiotic exposure: (1) use of antibiotics with a broad spectrum of activity against gram-negative bacteria or (2) treatment duration greater than 10 days.

Results.

A total of 533 cases were included: 320 with nonpurulent cellulitis, 44 with wound infection or purulent cellulitis, and 169 with abscess. Of 492 cases with complete prescribing data, the primary endpoint occurred in 394 (80%) cases and varied significantly across hospitals (64%–97%;P< .001). By logistic regression, independent predictors of the primary endpoint included wound infection or purulent cellulitis (odds ratio [OR], 5.12 [95% confidence interval (CI)], 1.46–17.88), head or neck involvement (OR, 2.83 [95% CI, 1.17–6.82]), adult cases (OR, 2.20 [95% CI, 1.18–4.11]), and admission to a community hospital (OR, 1.90 [95% CI, 1.05–3.44]).

Conclusions.

Among patients hospitalized for ABSSSI, use of antibiotics with broad gram-negative activity or treatment courses longer than 10 days were common. There may be substantial opportunity to reduce antibiotic exposure through shorter courses of therapy targeting gram-positive bacteria.

Infect Control Hosp Epidemiol2014;35(10):1241–1250
Population Structure, Fungicide Resistance Profile, and sdhB Mutation Frequency of Botrytis cinerea from Strawberry and Greenhouse-Grown Tomato in Greece
Authors: Konstantinou Sotirios , Veloukas Thomas , Leroch Michaela , Menexes George , Hahn Matthias , Karaoglanidis George
Published: August 2014

Botrytis cinerea is a pathogen with high genetic variability that has also shown high risk for fungicide resistance development. In total, 1,169 isolates obtained from strawberry (n = 297) and tomato (n = 872) in five geographic regions of Greece were tested for their sensitivity to several botryticides. A high frequency of isolates with multiple resistance to carbendazim, cyprodinil, pyraclostrobin, and boscalid was found in isolates from strawberry. In the isolates from tomato, the predominant phenotype was that of dual resistance to carbendazim and cyprodinil in the Crete island, of single resistance to carbendazim in the region of Preveza, and of sensitive isolates in the region of Kyparissia. None of the tested isolates was found to be fludioxonil resistant. High frequencies of boscalid-resistant phenotypes were observed in the strawberry isolates, while boscalid-resistance frequency in the tomato isolates was lower. H272R was the predominant sdhB mutation, associated with resistance to boscalid, in all the sampled isolates, while other sdhB mutations were found at low frequencies. B. cinerea group S, identified by the presence of a 21-bp insertion in the transcription factor mrr1 gene, was predominant within the tomato isolates obtained from all three sampled regions, with frequencies ranging from 62 to 75% of the isolates; whereas, within strawberry isolates, B. cinerea was predominant, with frequencies of 75 to 95%. Correlations of isolate genotype and fungicide resistance profile showed that B. cinerea sensu stricto isolates were more prone to the development of resistance to boscalid compared with the Botrytis group S isolates, which may explain the observed predominance of B. cinerea sensu stricto in strawberry fields.
Modulation of Stress versus Time Product during Mechanical Ventilation Influences Inflammation as Well as Alveolar Epithelial and Endothelial Response in Rats
Authors: Spieth Peter M. , Silva Pedro L. , Garcia Cristiane S. N. B. , Ornellas Debora S. , Samary Cynthia S. , Moraes Lillian , Bentes Maira , Morales Marcelo M. , Kasper Michael , Güldner Andreas , Huhle Robert , Koch Thea , Pelosi Paolo , de Abreu Marcelo Gama , Rocco Patricia R. M.
Published: August 2014

Background:

Mechanical ventilation can lead to lung biotrauma when mechanical stress exceeds safety thresholds. The authors investigated whether the duration of mechanical stress, that is, the impact of a stress versus time product (STP), influences biotrauma. The authors hypothesized that higher STP levels are associated with increased inflammation and with alveolar epithelial and endothelial cell injury.

Methods:

In 46 rats, Escherichia coli lipopolysaccharide (acute lung inflammation) or saline (control) was administered intratracheally. Both groups were protectively ventilated with inspiratory-to-expiratory ratios 1:2, 1:1, or 2:1 (n = 12 each), corresponding to low, middle, and high STP levels (STPlow, STPmid, and STPhigh, respectively). The remaining 10 animals were not mechanically ventilated.

Results:

In animals with mild acute lung inflammation, but not in controls: (1) messenger RNA expression of interleukin-6 was higher in STPhigh (28.1 ± 13.6; mean ± SD) and STPlow (28.9 ± 16.0) versus STPmid (7.4 ± 7.5) (P < 0.05); (2) expression of the receptor for advanced glycation end-products was increased in STPhigh (3.6 ± 1.6) versus STPlow (2.3 ± 1.1) (P < 0.05); (3) alveolar edema was decreased in STPmid (0 [0 to 0]; median, Q1 to Q3) compared with STPhigh (0.8 [0.6 to 1]) (P < 0.05); and (4) expressions of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 were higher in STPlow (3.0 ± 1.8) versus STPhigh (1.2 ± 0.5) and STPmid (1.4 ± 0.7) (P < 0.05), respectively.

Conclusions:

In the mild acute lung inflammation model used herein, mechanical ventilation with inspiratory-to-expiratory of 1:1 (STPmid) minimized lung damage, whereas STPhigh increased the gene expression of biological markers associated with inflammation and alveolar epithelial cell injury and STPlow increased markers of endothelial cell damage.
Using Nonechoplanar Diffusion-weighted MRI to Assess Treatment Response in Active Graves Orbitopathy: A Novel Approach with 2 Case Reports
Authors: Ritchie Ailsa E. , Lee Vickie , Feeney Claire , Lingam Ravi Kumar
Published: August 2014

Two patients (68 and 71 years, both female) with sight threatening, active Graves orbitopathy but low clinical activity score underwent MRI scans before and after intravenous corticosteroid treatment. Two MRI techniques, short-term inversion recovery and nonechoplanar diffusion-weighted imaging, were used. Apparent diffusion coefficient values reduced in patient 1 who had successful medical treatment and remained elevated in patient 2 who had an inadequate treatment response. Nonechoplanar diffusion-weighted imaging provided a quantitative measure of treatment response by calculation of the apparent diffusion coefficient. The novel use of nonechoplanar diffusion-weighted imaging for monitoring treatment response in Graves orbitopathy is illustrated but requires further validation.
Nasal aerodynamics protects brain and lung from inhaled dust in subterranean diggers,Ellobius talpinus
Authors: Moshkin M. P. , Petrovski D. V. , Akulov A. E. , Romashchenko A. V. , Gerlinskaya L. A. , Ganimedov V. L. , Muchnaya M. I. , Sadovsky A. S. , Koptyug I. V. , Savelov A. A. , Troitsky S. Yu , Moshkn Y. M. , Bukhtiyarov V. I. , Kolchanov N. A. , Sagdeev R. Z. , Fomin V. M.
Published: August 2014

Inhalation of air-dispersed sub-micrometre and nano-sized particles presents a risk factor for animal and human health. Here, we show that nasal aerodynamics plays a pivotal role in the protection of the subterranean mole voleEllobius talpinusfrom an increased exposure to nano-aerosols. Quantitative simulation of particle flow has shown that their deposition on the total surface of the nasal cavity is higher in the mole vole than in a terrestrial rodentMus musculus(mouse), but lower on the olfactory epithelium. In agreement with simulation results, we found a reduced accumulation of manganese in olfactory bulbs of mole voles in comparison with mice after the inhalation of nano-sized MnCl2aerosols. We ruled out the possibility that this reduction is owing to a lower transportation from epithelium to brain in the mole vole as intranasal instillations of MnCl2solution and hydrated nanoparticles of manganese oxide MnO · (H2O)xrevealed similar uptake rates for both species. Together, we conclude that nasal geometry contributes to the protection of brain and lung from accumulation of air-dispersed particles in mole voles.
A global model of the response of tropical and sub-tropical forest biodiversity to anthropogenic pressures
Authors: Newbold Tim , Hudson Lawrence N. , Phillips Helen R. P. , Hill Samantha L. L. , Contu Sara , Lysenko Igor , Blandon Abigayil , Butchart Stuart H. M. , Booth Hollie L. , Day Julie , De Palma Adriana , Harrison Michelle L. K. , Kirkpatrick Lucinda , Pynegar Edwin , Robinson Alexandra , Simpson Jake , Mace Georgina M. , Scharlemann Jörn P. W. , Purvis Andy
Published: August 2014

Habitat loss and degradation, driven largely by agricultural expansion and intensification, present the greatest immediate threat to biodiversity. Tropical forests harbour among the highest levels of terrestrial species diversity and are likely to experience rapid land-use change in the coming decades. Synthetic analyses of observed responses of species are useful for quantifying how land use affects biodiversity and for predicting outcomes under land-use scenarios. Previous applications of this approach have typically focused on individual taxonomic groups, analysing the average response of the whole community to changes in land use. Here, we incorporate quantitative remotely sensed data about habitats in, to our knowledge, the first worldwide synthetic analysis of how individual species in four major taxonomic groups—invertebrates, ‘herptiles’ (reptiles and amphibians), mammals and birds—respond to multiple human pressures in tropical and sub-tropical forests. We show significant independent impacts of land use, human vegetation offtake, forest cover and human population density on both occurrence and abundance of species, highlighting the value of analysing multiple explanatory variables simultaneously. Responses differ among the four groups considered, and—within birds and mammals—between habitat specialists and habitat generalists and between narrow-ranged and wide-ranged species.
Inferring species roles in metacommunity structure from species co-occurrence networks
Authors: Borthagaray Ana I. , Arim Matías , Marquet Pablo A.
Published: August 2014

A long-standing question in community ecology is what determines the identity of species that coexist across local communities or metacommunity assembly. To shed light upon this question, we used a network approach to analyse the drivers of species co-occurrence patterns. In particular, we focus on the potential roles of body size and trophic status as determinants of metacommunity cohesion because of their link to resource use and dispersal ability. Small-sized individuals at low-trophic levels, and with limited dispersal potential, are expected to form highly linked subgroups, whereas large-size individuals at higher trophic positions, and with good dispersal potential, will foster the spatial coupling of subgroups and the cohesion of the whole metacommunity. By using modularity analysis, we identified six modules of species with similar responses to ecological conditions and high co-occurrence across local communities. Most species either co-occur with species from a single module or are connectors of the whole network. Among the latter are carnivorous species of intermediate body size, which by virtue of their high incidence provide connectivity to otherwise isolated communities playing the role of spatial couplers. Our study also demonstrates that the incorporation of network tools to the analysis of metacommunity ecology can help unveil the mechanisms underlying patterns and processes in metacommunity assembly.
Quantitative genetics and modularity in cranial and mandibular morphology ofCalomys expulsus
Authors: Garcia Guilherme , Cerqueira Rui , Hingst-Zaher Erika , Marroig Gabriel
Published: August 2014

Patterns of genetic covariance between characters (represented by the covariance matrixG) play an important role in morphological evolution, since they interact with the evolutionary forces acting over populations. They are also expected to influence the patterns expressed in their phenotypic counterparts (P), because of limits imposed by multiple developmental and functional restrictions on the genotype/phenotype map. We have investigated genetic covariances in the skull and mandible of the vesper mouse (Calomys expulsus) in order to estimate the degree of similarity between genetic and phenotypic covariances and its potential roots on developmental and functional factors shaping those integration patterns. We use a classicad hocanalysis of morphological integration based on current state of art of developmental/functional factors during mammalian ontogeny and also applied a novel methodology that makes use of simulated evolutionary responses. We have obtainedPandGthat are strongly similar, for both skull and mandible; their similarity is achieved through the spatial and temporal organization of developmental and functional interactions, which are consistently recognized as hypothesis of trait associations in both matrices.
Statistical Mechanics of Multistable Perception
Authors: Atwal Gurinder S.
Published: August 2014

The stochastic dynamics of multistable perception poses an enduring challenge to our understanding of neural signal processing in the brain. We show that the emergence of perception switching and stability can be understood using principles of probabilistic Bayesian inference where the prior temporal expectations are matched to a scale-free power spectrum, characteristic of fluctuations in the natural environment. The optimal percept dynamics are inferred by an exact mapping of the statistical estimation problem to the motion of a dissipative quantum particle in a multi-well potential. In the bistable case the problem is further mapped to a long-ranged Ising model. Optimal inference in the presence of a 1/f noise prior leads to critical dynamics, exhibiting a dynamical phase transition from unstable perception to stable perception, as demonstrated in recent experiments. The effect of stimulus fluctuations and perception bias is also discussed.
An amino acid polymorphism in theDrosophilainsulin receptor demonstrates pleiotropic and adaptive function in life history traits
Authors: Paaby Annalise B. , Bergland Alan O. , Behrman Emily L. , Schmidt Paul S.
Published: August 2014

Finding the specific nucleotides that underlie adaptive variation is a major goal in evolutionary biology, but polygenic traits pose a challenge because the complex genotype-phenotype relationship can obscure the effects of individual alleles. However, natural selection working in large wild populations can shift allele frequencies and indicate functional regions of the genome. Previously, we showed that the two most common alleles of a complex amino acid insertion-deletion polymorphism in theDrosophilainsulin receptor show independent, parallel clines in frequency across the North American and Australian continents. Here, we report that the cline is stable over at least a five-year period and that the polymorphism also demonstrates temporal shifts in allele frequency concurrent with seasonal change. We tested the alleles for effects on levels of insulin signaling, fecundity, development time, body size, stress tolerance, and lifespan. We find that the alleles are associated with predictable differences in these traits, consistent with patterns ofDrosophilalife history variation across geography that likely reflect adaptation to the heterogeneous climatic environment. These results implicate insulin signaling as a major mediator of life history adaptation inDrosophila, and suggest that life history tradeoffs can be explained by extensive pleiotropy at a single locus.
Model-Assisted Analysis of Sugar Metabolism throughout Tomato Fruit Development Reveals Enzyme and Carrier Properties in Relation to Vacuole Expansion
Authors: Beauvoit Bertrand P. , Colombié Sophie , Monier Antoine , Andrieu Marie-Hélène , Biais Benoit , Bénard Camille , Chéniclet Catherine , Dieuaide-Noubhani Martine , Nazaret Christine , Mazat Jean-Pierre , Gibon Yves
Published: August 2014

A kinetic model combining enzyme activity measurements and subcellular compartmentation was parameterized to fit the sucrose, hexose, and glucose-6-P contents of pericarp throughout tomato (Solanum lycopersicum) fruit development. The model was further validated using independent data obtained from domesticated and wild tomato species and on transgenic lines. A hierarchical clustering analysis of the calculated fluxes and enzyme capacities together revealed stage-dependent features. Cell division was characterized by a high sucrolytic activity of the vacuole, whereas sucrose cleavage during expansion was sustained by both sucrose synthase and neutral invertase, associated with minimal futile cycling. Most importantly, a tight correlation between flux rate and enzyme capacity was found for fructokinase and PPi-dependent phosphofructokinase during cell division and for sucrose synthase, UDP-glucopyrophosphorylase, and phosphoglucomutase during expansion, thus suggesting an adaptation of enzyme abundance to metabolic needs. In contrast, for most enzymes, flux rates varied irrespectively of enzyme capacities, and most enzymes functioned at <5% of their maximal catalytic capacity. One of the major findings with the model was the high accumulation of soluble sugars within the vacuole together with organic acids, thus enabling the osmotic-driven vacuole expansion that was found during cell division.