bluuebunny/crossref_metadata_2025 huggingface dataset:
Hybrid-state emission in a polythienylenevinylene derivative with an electron deficient moiety
Authors: Lafalce Evan , Jiang Xiaomei , Pan Jianjun , Whittington Christi , Larsen Randy , Sanow Logan P. , Zhang Cheng
Published: April 2015

The photoluminescence (PL) of a novel imide-substituted poly(3-thienylenevinylene) derivative (imidePTV) was studied in film and solution. PL quantum efficiency was measured to be more than two orders of magnitude larger than its nonluminescent counterpart, namely, alkyl-substituted PTV and was interpreted as evidence for a near degeneracy of optically allowed 11Bu and optically forbidden 21Ag excitonic states. As a result, coexistence of 21Ag and 11Bu emissions was observed, and the predominance was found to be sensitive to temperature and morphological environment. PL of solutions in solvents of higher polarity and polarizability and from low-temperature films was dominated by the transition from the dipole allowed 11Bu state. On the other hand, the PL spectra of films at high temperature and solutions in solvents of low polarity and polarizability were primarily from the 21Ag state that obtains a finite transmission moment from an asymmetric perturbation mixing with the 11Bu.
Chlorophyll fluorescence control in microalgae by biogenic guanine crystals
Authors: Miyashita Yuito , Iwasaka Masakazu , Endo Hirotoshi
Published: April 2015

Magnetic fields were applied to water suspensions of guanine crystals to induce changes in light scattering as a possible way to control photosynthesis in microalgae. The effect of guanine microcrystals with and without an applied magnetic field on the photosynthesis of a unicellular microalgae (plant), Pleurochrysis. carterae (P. carterae), was investigated by examining chlorophyll fluorescence. The fluorescence intensity at 600–700 nm of the photosynthetic cells increased remarkably when the concentration ratio of guanine microcrystals was 10 times larger than that of the cells. This increase in fluorescence occurred reproducibly and was proportional to the amount of guanine microcrystals added. It is speculated that the guanine microcrystals enhance the intensity of the excitation light on the cells by concentrating the excitation light or prolonging the time of light exposure to the cells. Moreover, applying a 500-mT magnetic field allowed modulation of the fluorescence intensity, depending on the direction of the fluorescence light.
Modelling a point absorbing wave energy converter by the equivalent electric circuit theory: A feasibility study
Authors: Hai Ling , Svensson Olle , Isberg Jan , Leijon Mats
Published: April 2015

There is a need to have a reliable tool to quickly assess wave energy converters (WECs). This paper explores whether it is possible to apply the equivalent electric circuit theory as an evaluation tool for point absorbing WEC system modelling. The circuits were developed starting from the force analysis, in which the hydrodynamic, mechanical, and electrical parameters were expressed by electrical components. A methodology on how to determine the parameters for electrical components has been explained. It is found that by using a multimeter, forces in the connection line and the absorbed electric power can be simulated and read directly from the electric circuit model. Finally, the circuit model has been validated against the full scale offshore experiment. The results indicated that the captured power could be predicted rather accurately and the line force could be estimated accurately near the designed working condition of the WEC.
Si nanowire growth on sapphire: Classical incubation, reverse reaction, and steady state supersaturation
Authors: Shakthivel Dhayalan , Rathkanthiwar Shashwat , Raghavan Srinivasan
Published: April 2015

Si nanowire growth on sapphire substrates by the vapor-liquid-solid (VLS) method using Au catalyst particles has been studied. Sapphire was chosen as the substrate to ensure that the vapor phase is the only source of Si. Three hitherto unreported observations are described. First, an incubation period of 120–480 s, which is shown to be the incubation period as defined in classical nucleation theory, is reported. This incubation period permits the determination of a desolvation energy of Si from Au-Si alloys of 15 kT. Two, transmission electron microscopy studies of incubation, point to Si loss by reverse reaction as an important part of the mechanism of Si nanowire growth by VLS. Three, calculations using these physico-chemical parameters determined from incubation and measured steady state growth rates of Si nanowires show that wire growth happens from a supersaturated catalyst droplet.
Magnetoelectric switching of perpendicular exchange bias in Pt/Co/α-Cr2O3/Pt stacked films
Authors: Toyoki Kentaro , Shiratsuchi Yu , Kobane Atsushi , Mitsumata Chiharu , Kotani Yoshinori , Nakamura Tetsuya , Nakatani Ryoichi
Published: April 2015

We report the realization of magnetoelectric switching of the perpendicular exchange bias in Pt/Co/α-Cr2O3/Pt stacked films. The perpendicular exchange bias was switched isothermally by the simultaneous application of magnetic and electric fields. The threshold electric field required to switch the perpendicular exchange bias was found to be inversely proportional to the magnetic field, which confirmed the magnetoelectric mechanism of the process. The observed temperature dependence of the threshold electric field suggested that the energy barrier of the antiferromagnetic spin reversal was significantly lower than that assuming the coherent rotation. Pulse voltage measurements indicated that the antiferromagnetic domain propagation dominates the switching process. These results suggest an analogy of the electric-field-induced magnetization with a simple ferromagnet.
Magnetotransport properties of a few-layer graphene-ferromagnetic metal junctions in vertical spin valve devices
Authors: Entani Shiro , Naramoto Hiroshi , Sakai Seiji
Published: April 2015

Magnetotransport properties were studied for the vertical spin valve devices with two junctions of permalloy electrodes and a few-layer graphene interlayer. The graphene layer was directly grown on the bottom electrode by chemical vapor deposition. X-ray photoelectron spectroscopy showed that the permalloy surface fully covered with a few-layer graphene is kept free from oxidation and contamination even after dispensing and removing photoresist. This enabled fabrication of the current perpendicular to plane spin valve devices with a well-defined interface between graphene and permalloy. Spin-dependent electron transport measurements revealed a distinct spin valve effect in the devices. The magnetotransport ratio was 0.8% at room temperature and increased to 1.75% at 50 K. Linear current-voltage characteristics and resistance increase with temperature indicated that ohmic contacts are realized at the relevant interfaces.
Thermal conductivity prediction of magnetic composite sheet for near-field electromagnetic absorption
Authors: Lee Joonsik , Nam Baekil , Ko Frank K. , Kim Ki Hyeon
Published: April 2015

The magnetic composite sheets were designed by using core-shell structured magnetic fillers instead of uncoated magnetic fillers to resolve concurrently the electromagnetic interference and thermal radiation problems. To predict the thermal conductivity of composite sheet, we calculated the thermal conductivity of the uncoated magnetic fillers and core-shell structured fillers. And then, the thermal conductivity of the magnetic composites sheet filled with core-shell structured magnetic fillers was calculated and compared with that of the uncoated magnetic fillers filled in composite sheet. The magnetic core and shell material are employed the typical Fe-Al-Si flake (60 μm × 60 μm × 1 μm) and 250 nm-thick AlN with high thermal conductivity, respectively. The longitudinal thermal conductivity of the core-shell structured magnetic composite sheet (2.45 W/m·K) enhanced about 33.4% in comparison with that of uncoated magnetic fillers (1.83 W/m·K) for the 50 vol. % magnetic filler in polymer matrix.
Role of the antiferromagnetic pinning layer on spin wave properties in IrMn/NiFe based spin-valves
Authors: Gubbiotti G. , Tacchi S. , Del Bianco L. , Bonfiglioli E. , Giovannini L. , Tamisari M. , Spizzo F. , Zivieri R.
Published: April 2015

Brillouin light scattering (BLS) was exploited to study the spin wave properties of spin-valve (SV) type samples basically consisting of two 5 nm-thick NiFe layers (separated by a Cu spacer of 5 nm), differently biased through the interface exchange coupling with an antiferromagnetic IrMn layer. Three samples were investigated: a reference SV sample, without IrMn (reference); one sample with an IrMn underlayer (10 nm thick) coupled to the bottom NiFe film; one sample with IrMn underlayer and overlayer of different thickness (10 nm and 6 nm), coupled to the bottom and top NiFe film, respectively. The exchange coupling with the IrMn, causing the insurgence of the exchange bias effect, allowed the relative orientation of the NiFe magnetization vectors to be controlled by an external magnetic field, as assessed through hysteresis loop measurements by magneto-optic magnetometry. Thus, BLS spectra were acquired by sweeping the magnetic field so as to encompass both the parallel and antiparallel alignment of the NiFe layers. The BLS results, well reproduced by the presented theoretical model, clearly revealed the combined effects on the spin dynamic properties of the dipolar interaction between the two NiFe films and of the interface IrMn/NiFe exchange coupling.
Selective detection of heavy metal ions by self assembled chemical field effect transistors
Authors: Ruan Hang , Kang Yuhong , Gladwin Elizabeth , Claus Richard O.
Published: April 2015

Multiple layer-by-layer sensor material modifications were designed and implemented to achieve selectivity of semiconductor based chemical field effect transistors (ChemFETs) to particular heavy metal ions. The ChemFET sensors were fabricated and modified in three ways, with the intent to initially target first mercury and lead ions and then chromium ions, respectively. Sensor characterization was performed with the gate regions of the sensor elements exposed to different concentrations of target heavy metal ion solutions. A minimum detection level in the range of 0.1 ppm and a 10%–90% response time of less than 10 s were demonstrated. By combining layer-by-layer gold nanoparticles and lead ionophores, a sensor is produced that is sensitive and selective not only to chromium but also to Cr3+ and Cr6+. This result supports the claim that high selectivity can be achieved by designing self-assembled bonding for lead, arsenic, chromium, cesium, mercury, and cadmium.
Finite Larmor radius effects on the (m = 2, n = 1) cylindrical tearing mode
Authors: Chen Y. , Chowdhury J. , Parker S. E. , Wan W.
Published: April 2015

New field solvers are developed in the gyrokinetic code GEM [Chen and Parker, J. Comput. Phys. 220, 839 (2007)] to simulate low-n modes. A novel discretization is developed for the ion polarization term in the gyrokinetic vorticity equation. An eigenmode analysis with finite Larmor radius effects is developed to study the linear resistive tearing mode. The mode growth rate is shown to scale with resistivity as γ ∼ η1∕3, the same as the semi-collisional regime in previous kinetic treatments [Drake and Lee, Phys. Fluids 20, 1341 (1977)]. Tearing mode simulations with gyrokinetic ions are verified with the eigenmode calculation.
Flower-like carbonyl iron powder modified by nanoflakes: Preparation and microwave absorption properties
Authors: Yu Miao , Yang Pingan , Fu Jie , Liu Shuzhi
Published: April 2015

In this paper, flower-like carbonyl iron powder (CIP) is prepared under normal temperature and pressure by a simple method of chemical reduction. This flower-like morphology is conducive to forming discontinuous network, enhancing diffuse scattering of the incident microwave and polarizing more interface charges. Those are all in favor of electromagnetic wave penetration and absorption. The test results show that compared with the unmodified CIP, the electromagnetic wave absorbing property of flower-like CIP is significantly improved in X-band. It is concluded that this research paves a way to enhance the microwave absorption properties of spherical metal particles.
Two Efficient One-Pot Approaches for Regioselective Synthesis of New 3-Arylpyridazino[4,3-c]quinolin-5(6H)-ones
Authors: Rimaz Mehdi
Published: April 2015

Two efficient regioselective approaches for the one-pot synthesis of 3-arylpyridazino[4,3-c]quinolin-5(6H)-one derivatives are reported, by the three-component reaction of arylglyoxal monohydrates, quinoline-2,4-diol, and hydrazinium dihydrochloride or hydrazine hydrate in ethanol and pyridine. In ethanol, the reactions were catalyzed by 1,4-diazobicyclo[2,2,2]octane. The features of both procedures are high regioselectivity, mild reaction conditions, good to high yields, and operational simplicity.
NK cells require IL-28R for optimal in vivo activity
Authors: Souza-Fonseca-Guimaraes Fernando , Young Arabella , Mittal Deepak , Martinet Ludovic , Bruedigam Claudia , Takeda Kazuyoshi , Andoniou Christopher E. , Degli-Esposti Mariapia A. , Hill Geoffrey R. , Smyth Mark J.
Published: April 2015

Significance

Natural killer (NK) cells are naturally circulating innate lymphocytes that sense altered cells, including pathogen-activated and early-transformed cells. The signals that prime the NK cell to respond are not completely understood, but cytokines, such as IL-12, IL-18, and type I interferon (IFN-αβ) from antigen-presenting cells, are appreciated to be key to NK cell effector functions in response to bacteria, viruses, and tumors. In this light, another class of IFN, IFN type III (IFN-λ), has been described that shares some common functions with IFN-αβ, but with a more restricted cellular expression. Here, we demonstrate for the first time, to our knowledge, the ability of IFN-λ to directly regulate NK cell effector functions in vivo, alone and in the context of IFN-αβ.
Polyunsaturated fatty acid analogs act antiarrhythmically on the cardiac I
Ks
channel
Authors: Liin Sara I. , Silverå Ejneby Malin , Barro-Soria Rene , Skarsfeldt Mark Alexander , Larsson Johan E. , Starck Härlin Frida , Parkkari Teija , Bentzen Bo Hjorth , Schmitt Nicole , Larsson H. Peter , Elinder Fredrik
Published: April 2015

Significance

More than 300 mutations in the genes encoding the cardiac I
Ks
channel have been identified in patients with cardiac arrhythmia. These mutations cause either loss of function or gain of function of the I
Ks
channel. This study describes how polyunsaturated fatty acids and their analogues activate or inhibit the I
Ks
channel. These modulators can restore rhythmic firing in arrhythmic firing cardiac myocytes and restore prolonged QT interval in guinea pig hearts. The study also describes a mechanism by which an auxiliary β-subunit alters the pharmacological sensitivity of the I
Ks
channel. Our findings may form the basis for future design of antiarrhythmic compounds that target I
Ks
channels for treating different cardiac arrhythmias caused by mutations in the I
Ks
channel.
Cell growth defect factor 1 is crucial for the plastid import of NADPH:protochlorophyllide oxidoreductase A in
Arabidopsis thaliana
Authors: Reinbothe Steffen , Gray John , Rustgi Sachin , von Wettstein Diter , Reinbothe Christiane
Published: April 2015

Significance

As a component of the photosynthetic machinery, chlorophyll (Chl) absorbs light energy and is involved in energy transfer in the course of photosynthesis. Because of this molecule, however, photosynthetic organisms are also prone to photooxidative damage. Excited Chl molecules in the photosynthetic reaction centers interact with molecular oxygen and provoke the production of highly toxic singlet oxygen. In this article, we show how higher plants prevent self-poisoning with molecular oxygen during greening and identify a protein that controls Chl precursor homoeostasis.
The Spawning Success of Early Maturing Resident Hatchery Chinook Salmon in a Natural River System
Authors: Ford Michael , Pearsons Todd N. , Murdoch Andrew
Published: April 2015

Hatchery propagation of spring Chinook Salmon Oncorhynchus tshawytscha has been shown to increase the proportion of males maturing as minijacks (age 2) or microjacks (age 1) relative to those proportions in wild populations. However, little is known about the success of early maturing males when they spawn in the wild. A captive broodstock program for spring Chinook Salmon in the White River (a tributary of the Wenatchee River, Washington) has a high rate of early male maturity. We used genetic parentage analysis to evaluate the spawning success of anadromous males in comparison with inferred early maturing resident, hatchery‐origin males that spawned naturally. Based on samples of juvenile offspring (n = 1,007–1,368 fish/year) and a nearly complete sample of the potential anadromous parents, we found that during 2006–2009, 26–45% of the progeny did not have a male parent in the anadromous sample. In contrast, 0–23% of the progeny did not have a female parent represented in the sample. Using grandparentage analysis, we eliminated wild resident fish as a likely source of the unsampled male parents; thus, we concluded that those male parents were most likely early maturing resident fish that had been released from the captive broodstock program. The inferred spawning success of the unsampled resident males was significantly lower than that of the anadromous males. The typical mating pattern was for an anadromous female to produce about two‐thirds of her offspring with one or two anadromous males and the remaining one‐third with as many as 12 or more apparently resident males. To our knowledge, this is the first study to present evidence of successful reproduction by early maturing resident, hatchery‐origin Chinook Salmon in the wild. The conservation implications of this finding are complex and will depend upon the genetic basis of early maturity and its causes in hatchery settings.
Production, optimization and characterization of polyhydroxybutyrate, a biodegradable plastic by Bacillus spp.
Authors: Bhagowati Pabitra , Pradhan Shreema , Dash Hirak R , Das Surajit
Published: April 2015

Poly-β-hydroxybutyrate (PHB) is the intracellular lipid reserve accumulated by many bacteria. The most potent terrestrial bacterium Bacillus cereus SE-1 showed more PHB accumulating cells (22.1 and 40% after 48 and 72 h) than that of the marine Bacillus sp. CS-605 (5 and 33% after 48 and 72 h). Both the isolates harbored phbB gene and the characteristics C=O peak was observed in the extracted PHB by Fourier transformed infrared spectroscopy analysis. Maltose was found to be the most suitable carbon source for the accumulation of PHB in B. cereus SE-1. The extracted PHB sample from B. cereus SE-1 was blended with a thermoplastic starch (TS) and an increased thermoplasticity and decreased crystallinity were observed after blending in comparison to the standard PHB. The melting temperature (Tm), melting enthalpy (∆Hf), and crystallinity (Xc) of the blended PHB sample were found to be 109.4 °C, 64.58 J/g, and 44.23%, respectively.
Physiological Responses of Hard Red Winter Wheat to Infection by Wheat streak mosaic virus
Authors: Pradhan Gautam P. , Xue Qingwu , Jessup Kirk E. , Hao Baozhen , Price Jacob A. , Rush Charles M.
Published: April 2015

Wheat streak mosaic virus (WSMV) causes significant yield loss in hard red winter wheat in the U.S. Southern High Plains. Despite the prevalence of this pathogen, little is known about the physiological response of wheat to WSMV infection. A 2-year study was initiated to (i) investigate the effect of WSMV, inoculated at different development stages, on shoot and root growth, water use, water use efficiency (WUE), and photosynthesis and (ii) understand the relationships between yield and photosynthetic parameters during WSMV infection. Two greenhouse experiments were conducted with two wheat cultivars mechanically inoculated with WSMV at different developmental stages, from three-leaf to booting. WSMV inoculated early, at three- to five-leaf stage, resulted in a significant reduction in shoot biomass, root dry weight, and yield compared with wheat infected at the jointing and booting stages. However, even when inoculated as late as jointing, WSMV still reduced grain yield by at least 53%. Reduced tillers, shoot biomass, root dry weight, water use, and WUE contributed to yield loss under WSMV infection. However, infection by WSMV did not affect rooting depth and the number of seminal roots but reduced the number of nodal roots. Leaf photosynthetic parameters (chlorophyll [SPAD], net photosynthetic rate [Pn], stomatal conductance [Gs], intercellular CO2 concentration [Ci], and transpiration rate [Tr]) were reduced when infected by WSMV, and early infection reduced parameters more than late infection. Photosynthetic parameters had a linear relationship with grain yield and shoot biomass. The reduced Pn under WSMV infection was mainly in response to decreased Gs, Ci, and SPAD. The results of this study indicated that leaf chlorophyll and gas exchange parameters can be used to quantify WSMV effects on biomass and grain yield in wheat.
Incidental Durotomy in Open Versus Tubular Revision Microdiscectomy
Authors: Kogias Evangelos , Klingler Jan-Helge , Franco Jimenez Pamela , Vasilikos Ioannis , Sircar Ronen , Scholz Christoph , Hubbe Ulrich
Published: April 2015

Study Design:

Retrospective case-control study.

Objective:

To compare the incidence, management, and outcome of incidental durotomy in revision microdiscectomy with open and minimal-access surgery.

Summary of Background Data:

Incidental durotomy occurs with a variable incidence of 3%–27% in spine surgery. The highest rate occurs in revision microdiscectomy. The intraoperative and postoperative management of dural tears varies in the literature and the definite impact on clinical outcome has to be clarified.

Methods:

This is a retrospective study of medical records of 135 patients who underwent revision microdiscectomy, divided into 2 subgroups: OPEN (n=82) versus minimal-access surgery (MINI, n=53). Occurrence of intraoperative dural tears, intraoperative and postoperative management of durotomy, and clinical outcomes, according to MacNab criteria, were retrospectively examined. Statistical comparisons for categorical values between groups were accomplished using the 2-tailed Fisher exact test. P-values <0.05 were considered to be statistically significant.

Results:

The incidence of durotomy in group OPEN was 19.5% (n=16/82) and in group MINI 17.0% (n=9/53) (P=0.822). The majority of durotomies (23/25) were repaired with an absorbable fibrin sealant patch alone. Postoperative cerebrospinal fluid fistula occurred only in 1 case of the OPEN group and was treated with lumbar drainage without the need for a reoperation. Patients with durotomy of the MINI group tended to have better outcome compared with those of the OPEN group without being statistically significant.

Conclusions:

The incidence of durotomy and postoperative cerebrospinal fluid fistula in lumbar revision microdiscectomy does not significantly differ between minimal-access and standard open procedures. The application of a fibrin sealant patch alone is an effective strategy for dural repair in revision lumbar microdiscectomy.
Delayed Presentation of Jejuno-Jejunal Fistula With Stricture After Physical Child Abuse
Authors: Solaiman Adil Z. , Kulaylat Afif N. , Santos Mary C. , Rocourt Dorothy V. , Methratta Sosamma T. , Millington Karmaine , Alexander Chandran P.
Published: April 2015

Small intestinal injury is seldom described in the context of child abuse. Signs and symptoms are subtle, often leading to delays in diagnosis. We describe a 3-year-old boy initially admitted with severe blunt abdominal trauma from physical child abuse. He was successfully managed nonoperatively. The child was then hospitalized several times for nonspecific abdominal symptoms until diagnostic laparoscopy discovered a jejunal stricture with a proximal jejuno-jejunal fistula. Symptoms fully resolved after resection. Delayed presentation of small intestinal injury should remain on the differential diagnosis in the evaluation of persistent abdominal symptoms in a child with a prior history of physical abuse, even if imaging studies do not reveal specific abnormalities.
Secondary breakup of a drop at moderate Weber numbers
Authors: Jain Mohit , Prakash R. Surya , Tomar Gaurav , Ravikrishna R. V.
Published: April 2015

We present volume of fluid based numerical simulations of secondary breakup of a drop with high density ratio (approx. 1000) and also perform experiments by injecting monodisperse water droplets in a continuous jet of air and capture the breakup regimes, namely, bag formation, bag-stamen, multibag and shear breakup, observed in the moderate Weber number range (20–120). We observe an interesting transition regime between bag and shear breakup for
We
=80, in both simulations as well as experiments, where the formation of multiple lobes, is observed, instead of a single bag, which are connected to each other via thicker rim-like threads that hold them. We show that the transition from bag to shear breakup occurs owing to the rim dynamics which shows retraction under capillary forces at
We
=80, whereas the rim is sheared away with flow at
We
=120 thus resulting in a backward facing bag. The drop characteristics and timescales obtained in simulations are in good agreement with experiments. The drop size distribution after the breakup shows bimodal nature for the single-bag breakup mode and a unimodal nature following lognormal distribution for higher Weber numbers.
Propagation of elastic waves through textured polycrystals: application to ice
Authors: Maurel Agnès , Lund Fernando , Montagnat Maurine
Published: April 2015

The propagation of elastic waves in polycrystals is revisited, with an emphasis on configurations relevant to the study of ice. Randomly oriented hexagonal single crystals are considered with specific, non-uniform, probability distributions for their major axis. Three typical textures or fabrics (i.e. preferred grain orientations) are studied in detail: one cluster fabric and two girdle fabrics, as found in ice recovered from deep ice cores. After computing the averaged elasticity tensor for the considered textures, wave propagation is studied using a wave equation with elastic constantsc=〈c〉+δcthat are equal to an average plus deviations, presumed small, from that average. This allows for the use of the Voigt average in the wave equation, and velocities are obtained solving the appropriate Christoffel equation. The velocity for vertical propagation, as appropriate to interpret sonic logging measurements, is analysed in more details. Our formulae are shown to be accurate at the 0.5% level and they provide a rationale for previous empirical fits to wave propagation velocities with a quantitative agreement at the 0.07–0.7% level. We conclude that, within the formalism presented here, it is appropriate to use, with confidence, velocity measurements to characterize ice fabrics.
Multiplicity results for the non-homogeneous fractionalp-Kirchhoff equations with concave–convex nonlinearities
Authors: Xiang Mingqi , Zhang Binlin , Ferrara Massimiliano
Published: April 2015

In this paper, we are interested in the multiplicity of solutions for a non-homogeneousp-Kirchhoff-type problem driven by a non-local integro-differential operator. As a particular case, we deal with the following elliptic problem of Kirchhoff type with convex–concave nonlinearities:a+b∬R2N|u(x)−u(y)|p|x−y|N+sp dx dyθ−1(−Δ)psu=λω1(x)|u|q−2u+ω2(x)|u|r−2u+h(x)in RN,where(−Δ)psis the fractionalp-Laplace operator,a+b>0 witha,b∈R0+, λ>0 is a real parameter,0<s<1<p<∞withsp<N, 1<q<p≤θp<r<Np/(N−sp),ω1,ω2,hare functions which may change sign inRN. Under some suitable conditions, we obtain the existence of two non-trivial entire solutions by applying the mountain pass theorem and Ekeland's variational principle. A distinguished feature of this paper is thatamay be zero, which means that the above-mentioned problem is degenerate. To the best of our knowledge, our results are new even in the Laplacian case.
Linking effects of anthropogenic debris to ecological impacts
Authors: Browne Mark Anthony , Underwood A. J. , Chapman M. G. , Williams Rob , Thompson Richard C. , van Franeker Jan A.
Published: April 2015

Accelerated contamination of habitats with debris has caused increased effort to determine ecological impacts. Strikingly, most work on organisms focuses on sublethal responses to plastic debris. This is controversial because (i) researchers have ignored medical insights about the mechanisms that link effects of debris across lower levels of biological organization to disease and mortality, and (ii) debris is considered non-hazardous by policy-makers, possibly because individuals can be injured or removed from populations and assemblages without ecological impacts. We reviewed the mechanisms that link effects of debris across lower levels of biological organization to assemblages and populations. Using plastic, we show microplastics reduce the ‘health’, feeding, growth and survival of ecosystem engineers. Larger debris alters assemblages because fishing-gear and tyres kill animals and damage habitat-forming plants, and because floating bottles facilitate recruitment and survival of novel taxa. Where ecological linkages are not known, we show how to establish hypothetical links by synthesizing studies to assess the likelihood of impacts. We also consider how population models examine ecological linkages and guide management of ecological impacts. We show that by focusing on linkages to ecological impacts rather than the presence of debris and its sublethal impacts, we could reduce threats posed by debris.
Vocal turn-taking in a non-human primate is learned during ontogeny
Authors: Chow Cecilia P. , Mitchell Jude F. , Miller Cory T.
Published: April 2015

Conversational turn-taking is an integral part of language development, as it reflects a confluence of social factors that mitigate communication. Humans coordinate the timing of speech based on the behaviour of another speaker, a behaviour that is learned during infancy. While adults in several primate species engage in vocal turn-taking, the degree to which similar learning processes underlie its development in these non-human species or are unique to language is not clear. We recorded the natural vocal interactions of common marmosets (Callithrix jacchus) occurring with both their sibling twins and parents over the first year of life and observed at least two parallels with language development. First, marmoset turn-taking is a learned vocal behaviour. Second, marmoset parents potentially played a direct role in guiding the development of turn-taking by providing feedback to their offspring when errors occurred during vocal interactions similarly to what has been observed in humans. Though species-differences are also evident, these findings suggest that similar learning mechanisms may be implemented in the ontogeny of vocal turn-taking across our Order, a finding that has important implications for our understanding of language evolution.
Testing the myth: tolerant dogs and aggressive wolves
Authors: Range Friederike , Ritter Caroline , Virányi Zsófia
Published: April 2015

Cooperation is thought to be highly dependent on tolerance. For example, it has been suggested that dog–human cooperation has been enabled by selecting dogs for increased tolerance and reduced aggression during the course of domestication (‘emotional reactivity hypothesis’). However, based on observations of social interactions among members of captive packs, a few dog–wolf comparisons found contradictory results. In this study, we compared intraspecies aggression and tolerance of dogs and wolves raised and kept under identical conditions by investigating their agonistic behaviours and cofeeding during pair-wise food competition tests, a situation that has been directly linked to cooperation. We found that in wolves, dominant and subordinate members of the dyads monopolized the food and showed agonistic behaviours to a similar extent, whereas in dogs these behaviours were privileges of the high-ranking individuals. The fact that subordinate dogs rarely challenged their higher-ranking partners suggests a steeper dominance hierarchy in dogs than in wolves. Finally, wolves as well as dogs showed only rare and weak aggression towards each other. Therefore, we suggest that wolves are sufficiently tolerant to enable wolf–wolf cooperation, which in turn might have been the basis for the evolution of dog–human cooperation (canine cooperation hypothesis).
Antifungal and antibacterial activities of Streptomyces polymachus sp. nov. isolated from soil
Authors: Nguyen Tuan Manh , Kim Jaisoo
Published: April 2015

Strain T258Twas isolated from forest soil at Bongnae Falls, South Korea. The strain exhibited antimicrobial and antifungal activity against the following strains:Bacillus subtilis,Staphylococcus aureus,Pseudomonas aeruginosa,Paenibacillus larvae,Escherichia coli,Candida albicansandAspergillus niger. Growth occurred on all ISP media tested (2, 3, 4, 5, 6 and 7), Czapek–Dox agar, potato dextrose agar, trypticase soy agar, Bennett's modified agar and nutrient agar at 28 °C. Aerial spores were produced solely on ISP Medium 4; the colour of the aerial mycelium was white and the substrate mycelium was ivory. Melanin production was negative on peptone–yeast extract iron agar (ISP Medium 6). The cell-wall peptidoglycan containedll-diaminopimelic acid, glutamic acid, alanine and glycine. Whole-cell hydrolysates contained glucose, ribose and galactose. The predominant menaquinones were MK-9(H6) and MK-9(H8) while the minor menaquinone was MK-10(H2). The polar lipids included diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The major fatty acids (>10 %) were C16 : 0(29.8 %), summed feature 3 (C16 : 1ω7cand/or C16 : 1ω6c) (15.1 %), anteiso-C15 : 0(13.5 %) and iso-C15 : 0(10.3 %). DNA–DNA similarity with other strains ranged between 37.84 ± 1.15 % and 50.25 ± 1.91 %. On the basis of these data, we suggest that strain T258Trepresents a novel species that belong to the genusStreptomyces, for which we propose a nameStreptomyces polymachussp. nov. The type strain is T258T( = KACC 18247T = KEMB 9005-212T = NBRC 110905T).
Occurrence, distribution and possible functional roles of simple sequence repeats in phytoplasma genomes
Authors: Wei Wei , Davis Robert E. , Suo Xiaobing , Zhao Yan
Published: April 2015

Phytoplasmas are unculturable, cell-wall-less bacteria that parasitize plants and insects. This transkingdom life cycle requires rapid responses to vastly different environments, including transitions from plant phloem sieve elements to various insect tissues and alternations among diverse plant hosts. Features that enable such flexibility in other microbes include simple sequence repeats (SSRs) — mutation-prone, phase-variable short DNA tracts that function as ‘evolutionary rheostats’ and enhance rapid adaptations. To gain insights into the occurrence, distribution and potentially functional roles of SSRs in phytoplasmas, we performed computational analysis on the genomes of five completely sequenced phytoplasma strains, ‘CandidatusPhytoplasma asteris’-related strains OYM and AYWB, ‘CandidatusPhytoplasma australiense’-related strains CBWB and SLY and ‘CandidatusPhytoplasma mali’-related strain AP-AT. The overall density of SSRs in phytoplasma genomes was higher than in representative strains of other prokaryotes. While mono- and trinucleotide SSRs were significantly overrepresented in the phytoplasma genomes, dinucleotide SSRs and other higher-order SSRs were underrepresented. The occurrence and distribution of long SSRs in the prophage islands and phytoplasma-unique genetic loci indicated that SSRs played a role in compounding the complexity of sequence mosaics in individual genomes and in increasing allelic diversity among genomes. Findings from computational analyses were further complemented by an examination of SSRs in varied additional phytoplasma strains, with a focus on potential contingency genes. Some SSRs were located in regions that could profoundly alter the regulation of transcription and translation of affected genes and/or the composition of protein products.
A cell-free framework for biological systems engineering
Authors: Niederholtmeyer Henrike , Sun Zachary Z. , Hori Yutaka , Yeung Enoch , Verpoorte Amanda , Murray Richard M. , Maerkl Sebastian J.
Published: April 2015

While complex dynamic biological networks control gene expression and metabolism in all living organisms, engineering comparable synthetic networks remains challenging1,2. Conducting extensive, quantitative and rapid characterization during the design and implementation process of synthetic networks is currently severely limited due to cumbersome molecular cloning and the difficulties associated with measuring parts, components and systems in cellular hosts. Engineering gene networks in a cell-free environment promises to be an efficient and effective approach to rapidly develop novel biological systems and understand their operating regimes3-5. However, it remains questionable whether complex synthetic networks behave similarly in cells and a cell-free environment, which is critical forin vitroapproaches to be of significance to biological engineering. Here we show that synthetic dynamic networks can be readily implemented, characterized, and engineered in a cell-free framework and consequently transferred to cellular hosts. We implemented and characterized the “repressilator”6, a three-node negative feedback oscillatorin vitro. We then used our cell-free framework to engineer novel three-node, four-node, and five-node negative feedback architectures going from the characterization of circuit components to the rapid analysis of complete networks. We validated our cell-free approach by transferring these novel three-node and five-node oscillators toEscherichia coli, resulting in robust and synchronized oscillations reflecting thein vitroobservation. We demonstrate that comprehensive circuit engineering can be performed in a cell-free system and that thein vitroresults have direct applicabilityin vivo. Cell-free synthetic biology thus has the potential to drastically speed up design-build-test cycles in biological engineering and enable the quantitative characterization of synthetic and natural networks.
Social feedback and the emergence of rank in animal society
Authors: Hobson Elizabeth A. , DeDeo Simon
Published: April 2015

Dominance hierarchies are group-level properties that emerge from the aggressions of individuals. Although individuals can gain critical benefits from their position in a hierarchy, we do not understand how real-world hierarchies form, or what signals and decision-rules individuals use to construct and maintain them in the absence of simple cues. A study of aggression in two groups of captive monk parakeets (Myiopsitta monachus) found a transition to large-scale ordered aggression occurred in newly-formed groups after one week, with individuals thereafter preferring to direct aggression against those nearby in rank. We describe two mechanisms by which individuals may determine rank order: inference based on overall levels of aggression, or on subsets of the aggression network. Both pathways were predictive of individual decisions to aggress. Based on these results, we present a new theory, of a feedback loop between knowledge of rank and consequent behavior, that explains the transition to strategic aggression, and the formation and persistence of dominance hierarchies in groups capable of both social memory and social inference.
Risk analysis for container shipping: from a logistics perspective
Authors: Chang Chia-Hsun , Xu Jingjing , Song Dong-Ping
Published: April 2015

Purpose

– The purpose of this paper is to explore and analyse the risks in container shipping operations from a logistics perspective. In the paper, risks associated with the three flows in logistics − information, physical, and payment flow are identified and analysed.

Design/methodology/approach

– The use of case study method was first explained and justified. Second, risk identification was started with supporting references, several interviews were then conducted to identify and validate the potential risks in container shipping operations. A questionnaire was deployed to collect related data; and the impacts of the risks were then assessed and ranked using the method of risk mapping.

Findings

– The paper has identified a total of 35 risk factors and classified them into different categories. The paper has also revealed that the risks associated with physical flows have more serious risk impacts than the other types of risks; however, one of the risk factors associated with information flow (shippers hiding cargo information) is the most significant one among all the factors.

Originality/value

– Although many studies have been conducted on container shipping operational risks, no studies so far have approached this issue from a perspective that inclusively examines all the possible risks and comprehensively evaluates the relative importance of each of them. This study has identified the risks in container shipping operations, and analysed and ranked the level of these risks. The research further “refines” the findings of some previous studies by placing the risk factors addressed therein in a full “risk picture” which was developed systematically.
Service-dominant logic for managing the logistics-manufacturing interface
Authors: Lin Yong , Pekkarinen Saara , Ma Shihua
Published: April 2015

Purpose

– The purpose of this paper is to investigate the management of the logistics-manufacturing interface between the manufacturer and its logistics service provider from the perspective of the service-dominant (S-D) logic.

Design/methodology/approach

– The approach adopted is that of abductive reasoning through case study: data are primarily gleaned from semi-structured in-depth interviews. Field visits and secondary documentation are used to ensure data validity.

Findings

– The results show that the interface can be categorized into three levels: design interface between products and logistic services, process interface between manufacturing processes and service-offering processes, and information interface between manufacturing information systems and logistics information systems. The results also indicate that ten foundational premises of S-D logic, especially service-focussed, customer-oriented and rational views can be applied in defining and managing these interfaces.

Research limitations/implications

– This research contributes not only to the theory of S-D logic and managing interface, but also provides managers with guidelines of applying S-D logic to build a service-focussed, customer-oriented and relational logic to effectively manage the logistics-manufacturing interface. However, the research is limited to the context of automotive and logistics industries.

Originality/value

– Three levels of logistics-manufacturing interface, including design, process and information are identified, and S-D logic is applied to identify and manage the interface.
Ageing processes in laser sintered and injection moulded PA12 following hygienic reprocessing
Authors: Haerst Miriam Johanna , Wolf Romano , Schönberger Markus , Wintermantel Erich , Engelsing Kurt , Heidemeyer Peter , Bastian Martin
Published: April 2015

Purpose

– The purpose of this paper is to describe the ageing behaviour of polyamide 12 (PA12) after clinical use. The research is focused on the comparison of the processing methods injection moulding and laser sintering.

Design/methodology/approach

– Test specimens are subjected to a cyclic stress of defined bending, cleaning, disinfection and sterilization. The focus of interest in this research is the degradation and reduction of mechanical properties.

Findings

– Mechanical and optical changes of the materials after clinical use and hygienic reprocessing are evaluated and discussed.

Research limitations/implications

– This article is focused on PA12 and, therefore, enables a very specific statement for the clinical use of PA12. The processing methods could have different impacts depending on the polymer.

Originality/value

– With the increasing application of polymers in medical devices, the mechanical properties must be ensured even after long-term clinical use. A systematic research with a realistic and still-defined cyclic stress is shown in this paper. Especially the testing of laser sintered polymers compared to injection moulded material has an important message for future patient-specific products.
Diagnostic Performance of Focused Cardiac Ultrasound Performed by Emergency Physicians for the Assessment of Ascending Aorta Dilation and Aneurysm
Authors: Nazerian Peiman , Vanni Simone , Morello Fulvio , Castelli Matteo , Ottaviani Maddalena , Casula Claudia , Petrioli Alessandra , Bartolucci Maurizio , Grifoni Stefano
Published: April 2015

Objectives

The diagnostic performance of transthoracic focused cardiac ultrasound (FoCUS) performed by emergency physicians (EP) to estimate ascending aorta dimensions in the acute setting has not been prospectively studied. The diagnostic accuracy and the interobserver variability of EP‐performed FoCUS were investigated to estimate thoracic aortic dilation and aneurysm compared with the results of computed tomography angiography (CTA).

Methods

This was a prospective single‐center cohort study of a convenience sample of patients who underwent CTA in the emergency department for suspected aortic pathology. FoCUS was performed before CTA, and the maximum ascending aorta diameter evaluated in parasternal long‐axis view. Aorta diameter < 40 mm by visual estimation or by diameter measurement was considered normal. Measurements were recorded in all patients with aorta diameter ≥ 40 mm. Diagnostic accuracy of FoCUS for detection of aortic dilation (diameter ≥ 40 mm) and aneurysm (diameter ≥ 45 mm) were calculated considering the CTA result as reference standard. In a subgroup of patients, a second EP‐sonographer performed FoCUS to evaluate interobserver agreement for the diagnosis of ascending aorta dilation.

Results

A total of 140 patients were enrolled in the study. Ascending aorta dilation and aneurysm were detected with FoCUS in 50 (35.7%) and in 27 (17.8%) patients, respectively. Sensitivity and specificity of FoCUS were 78.6% (95% confidence interval [CI] = 65.6% to 88.4%) and 92.9% (95% CI = 85.1% to 97.3%), respectively, for ascending aorta dilation and 64.7% (95% CI = 46.5% to 80.2%) and 95.3% (95% CI = 89.3% to 98.4%), respectively, for ascending aorta aneurysm. Interobserver agreement of FoCUS was k = 0.82.

Conclusions

FoCUS performed by EP is specific for ascending aorta dilation and aneurysm when compared to CTA and appears a reproducible technique.
The Woman Next to Me: Pairing Powerful and Objectifying Representations of Women
Authors: Schooler Deborah
Published: April 2015

Previous research has documented negative effects of exposure to sexually objectifying media and positive effects of viewing women with more power and agency. The current study evaluates the effects of pairing these two types of representations of women on gender attitudes. Experimental stimuli were based on actual images from a student newspaper, where a statement from the new, female university president ran on the front page adjacent to a sexually objectifying ad. The experiment used a 2 (type of article) X 2 (type of ad) X 2 (gender) design to evaluate the independent and combined effects of viewing the statement from the president and the objectifying ad. Exposure to the objectifying ad was related to more attributional bias and marginally more stereotype production but was not related to hostile or benevolent sexism. Men who saw the objectifying ad alongside the president's statement rated the president as significantly less competent than other groups. Implications for the professional advancement of women are discussed, including the importance of context for media attention paid to female political figures.