bluuebunny/crossref_metadata_2025 huggingface dataset:
Microbead-assisted high resolution microwave planar ring resonator for organic-vapor sensing
Authors: Zarifi Mohammad H. , Fayaz Mohammadreza , Goldthorp Jordan , Abdolrazzaghi Mohammad , Hashisho Zaher , Daneshmand Mojgan
Published: February 2015

A microbead-assisted planar microwave resonator for organic vapor sensing applications is presented. The core of this sensor is a planar microstrip split-ring resonator, integrated with an active feedback loop to enhance the initial quality factor from 200 to ∼1 M at an operational resonance frequency of 1.42 GHz. Two different types of microbeads, beaded activated carbon (BAC) and polymer based (V503) beads, are investigated in non-contact mode for use as gas adsorbents in the gas sensing device. 2-Butoxyethanol (BE) is used in various concentrations as the target gas, and the transmitted power (S21) of the two port resonator is measured. The two main microwave parameters of resonance frequency and quality factor are extracted from S21 since these parameters are less susceptible to environmental and instrumental noise than the amplitude. Measured results demonstrate a minimum resonance frequency shift of 10 kHz for a 35 ppm concentration of BE exposure to carbon beads and 160 kHz for the polymer based adsorbent at the same concentration. The quality factor of the resonator also changed for different concentrations, but a distinguishable variation is observed for the BAC adsorbents. The high quality factor of the sensor provides the opportunity of real time monitoring of the adsorbent behaviors in remote sensing mode with very high resolution.
Resistive switching properties in CdZnTe films
Authors: Zha Gangqiang , Lin Yun , Zeng Dongmei , Tan Tingting , Jie Wanqi
Published: February 2015

The ternary II–VI compound semiconductor cadmium zinc telluride (CdZnTe) has bi-stable conduction characteristics. In this letter, CdZnTe films are grown on indium tin oxide (ITO) substrates by radio frequency magnetron sputtering. The current-voltage characteristics show that there is resistive switching in a structure consisting of an 800-nm-thick CdZnTe film, an Au Schottky contact, and an ITO bottom electrode. The electroresistance in Au/CdZnTe/ITO may be related to the polarization of the CdZnTe film and the Schottky contact.
Broadband light trapping and absorption of thin-film silicon sandwiched by trapezoidal surface and silver grating
Authors: Shi Wen-Bo , Fan Ren-Hao , Zhang Kun , Xu Di-Hu , Xiong Xiang , Peng Ru-Wen , Wang Mu
Published: February 2015

In this work, we demonstrate the high optical absorption efficiency of a thin-film silicon solar cell. In thin-film solar cells, the efficiency is strongly dependent on light trapping by structures capable of exciting different resonance modes. Here, we consider a trapezoidal surface design that not only reduces reflection with a gradient index of refraction but also excites multiple cavity modes. The absorption can be enhanced further by combining a plasmonic structure, i.e., a silver grating. For comparison, we have separately simulated the silver grating structure, trapezoidal surface structure, and the combined structure. The combined structure retains all absorption effects shown by the individual components, achieving broadband absorption with a high efficiency. The investigations provide a unique design for high-performance solar cells of thin-film silicon.
Room temperature ferromagnetism in conducting α-(In1−xFex)2O3 alloy films
Authors: Akaiwa K. , Kaneko K. , Fujita S. , Chikoidze E. , Dumont Y.
Published: February 2015

We have studied electronic transport and magnetic properties of α-(In1−xFex)2O3 alloy films. Temperature dependence of resistivity of the films showed semiconducting behavior of conductivity. Room temperature ferromagnetism was observed. Relatively high coercive fields indicated that observed ferromagnetism in α-(In1−xFex)2O3 films were not arisen from magnetic metallic iron nano-precipitates. Remanence measurement revealed the Curie temperature of 520 K and 620 K for α-(In0.52Fe0.48)2O3 and α-(In0.23Fe0.77)2O3 films, corresponding to a weakening of superexchange interactions in these alloys (with less magnetic iron cations) with respect to canted antiferromagnet α-Fe2O3. Nevertheless, Curie temperatures remain much higher than 300 K, and semiconducting behavior with low activation energy in resistivity for middle composition alloy, exhibiting combined multi-functionality of room ferromagnetism and semiconducting properties, in corundum alloys such as α-(Ga1−xFex)2O3 or α-Fe2−xTixO3.
High-Q microsphere resonators for angular velocity sensing in gyroscopes
Authors: An Panlong , Zheng Yongqiu , Yan Shubin , Xue Chenyang , Wang Wanjun , Liu Jun
Published: February 2015

A resonator gyroscope based on the Sagnac effect is proposed using a core unit that is generated by water-hydrogen flame melting. The relationship between the quality factor Q and diameter D is revealed. The Q factor of the spectral lines of the microsphere cavity coupling system, which uses tapered fibers, is found to be 106 or more before packaging with a low refractive curable ultraviolet polymer, although it drops to approximately 105 after packaging. In addition, a rotating test platform is built, and the transmission spectrum and discriminator curves of a microsphere cavity with Q of 3.22×106 are measured using a semiconductor laser (linewidth less than 1 kHz) and a real-time proportional-integral circuit tracking and feedback technique. Equations fitting the relation between the voltage and angular rotation rate are obtained. According to the experimentally measured parameters, the sensitivity of the microsphere-coupled system can reach 0.095∘/s.
Inhibition effect of space charge transportation on impulse breakdown performance of propylene carbonate with Al2O3 nanoparticles
Authors: Yang Qing , Yu Fei , Sima Wenxia , Yuan Tao , Jin Yang , Song He
Published: February 2015

Propylene carbonate-based nanofluids with Al2O3 nanoparticles exhibit 26.42% higher negative impulse breakdown voltage levels than those of pure propylene carbonate. The Kerr effect electro-optic method has been used to measure the space charges and electric field distribution of pure and modified nanofluids of propylene carbonate under impulse voltage. Test results indicate significant inhibition effect of space charge transportation in propylene carbonate-based nanofluids. The fast free charges are captured by nanoparticles and converted to slow-charged particles in nanofluids, which result in the uniform electric field distribution. The streamer propagation in nanofluids is also hindered, and the breakdown strength of nanofluids is improved under impulse conditions.
The post-growth effect on the properties of Cu2ZnSnS4 thin films
Authors: Seboui Zeineb , Gassoumi Abdelaziz , Cuminal Yvan , Turki Najoua Kamoun
Published: February 2015

Cu2ZnSnS4 (CZTS) thin film was deposited on glass substrate by spray pyrolysis technique using a methanolic solution. This film was annealed under nitrogen atmosphere for an hour at different annealing temperatures. The effect of the annealing temperature on composition, structure, morphology, electrical, and optical properties of CZTS films was investigated. Energy dispersive x-ray analysis showed that after the annealing process, the atomic ratio values tend to their stoichiometric values. Moreover, the X-ray diffraction (XRD) and Raman spectroscopy revealed a kesterite structure with (112) preferential orientation for both as-deposited and annealed CZTS films. Moreover, they exhibited an improvement in crystallinity after annealing which was confirmed by SEM analysis. The conductivity of the heated CZTS films showed also an important increase in crystallinity. The absorption edge shifted toward lower wavelengths leading to an increase in band gap energy for the annealed CZTS films.
Ferroelectric C* phase induced in a nematic liquid crystal matrix by a chiral non-mesogenic dopant
Authors: Pozhidaev E. P. , Torgova S. I. , Barbashov V. A. , Minchenko M. V. , Sulyanov S. N. , Dorovatovskii P. V. , Ostrovskii B. I. , Strigazzi A.
Published: February 2015

We report on a ferroelectric chiral smectic C (C*) phase obtained in a mixture of a nematic liquid crystal (NLC) and a chiral nonmesogenic dopant. The existence of C* phase was proven by calorimetric, dielectric and optical measurements, and also by X-rays analysis. The smectic C* which is obtained in such a way can flow, allowing to restore the ferroelectric liquid crystal layer structure in the electro-optical cells after action of the mechanical stress, as it happens with the cells filled with NLC. The proposed method of obtaining smectic C* material allows us to create innovative electro-optical cell combining the advantages of NLC (mechanical resilience) and smectic C* (high switching speed).
Enhanced conversion efficiency of dye-sensitized solar cells using a CNT-incorporated TiO2 slurry-based photoanode
Authors: Cai Jiaoping , Chen Zexiang , Li Jun , Wang Yan , Xiang Dong , Zhang Jijun , Li Hai
Published: February 2015

A new titanium dioxide (TiO2) slurry formulation is herein reported for the fabrication of TiO2 photoanode for use in dye-sensitized solar cells (DSSCs). The prepared TiO2 photoanode featured a highly uniform mesoporous structure with well-dispersed TiO2 nanoparticles. The energy conversion efficiency of the resulting TiO2 slurry-based DSSC was ∼63% higher than that achieved by a DSSC prepared using a commercial TiO2 slurry. Subsequently, the incorporation of acid-treated multi-walled carbon nanotubes (CNTs) into the TiO2 slurry was examined. More specifically, the effect of varying the concentration of the CNTs in this slurry on the performance of the resulting DSSCs was studied. The chemical state of the CNTs-incorporated TiO2 photoanode was investigated by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. A high energy conversion efficiency of 6.23% was obtained at an optimum CNT concentration of ∼0.06 wt.%. The obtained efficiency corresponds to a 63% enhancement when compared with that obtained from a DSSC based on a commercial TiO2 slurry. The higher efficiency was attributed to the improvement in the collection and transport of excited electrons in the presence of the CNTs.
Experimental realization of extraordinary acoustic transmission using Helmholtz resonators
Authors: Crow Brian C. , Cullen Jordan M. , McKenzie William W. , Koju Vijay , Robertson William M.
Published: February 2015

The phenomenon of extraordinary acoustic transmission through a solid barrier with an embedded Helmholtz resonator (HR) is demonstrated. The Helmholtz resonator consists of an embedded cavity and two necks that protrude, one on each side of the barrier. Extraordinary transmission occurs for a narrow spectral range encompassing the resonant frequency of the Helmholtz resonator. We show that an amplitude transmission of 97.5% is achieved through a resonator whose neck creates an open area of 6.25% of the total barrier area. In addition to the enhanced transmission, we show that there is a smooth, continuous phase transition in the transmitted sound as a function of frequency. The frequency dependent phase transition is used to experimentally realize slow wave propagation for a narrow-band Gaussian wave packet centered at the maximum transmission frequency. The use of parallel pairs of Helmholtz resonators tuned to different resonant frequencies is experimentally explored as a means of increasing the transmission bandwidth. These experiments show that because of the phase transition, there is always a frequency between the two Helmholtz resonant frequencies at which destructive interference occurs whether the resonances are close or far apart. Finally, we explain how the phase transition associated with Helmholtz-resonator-mediated extraordinary acoustic transmission can be exploited to produce diffractive acoustic components including sub-wavelength thickness acoustic lenses.
Effects of growth temperature and device structure on GaP solar cells grown by molecular beam epitaxy
Authors: Vaisman M. , Tomasulo S. , Masuda T. , Lang J. R. , Faucher J. , Lee M. L.
Published: February 2015

Gallium phosphide (GaP) is an attractive candidate for wide-bandgap solar cell applications, possessing the largest bandgap of the III-arsenide/phosphides without aluminum. However, GaP cells to date have exhibited poor internal quantum efficiency (IQE), even for photons absorbed by direct transitions, motivating improvements in material quality and device structure. In this work, we investigated GaP solar cells grown by molecular beam epitaxy over a range of substrate temperatures, employing a much thinner emitter than in prior work. Higher growth temperatures yielded the best solar cell characteristics, indicative of increased diffusion lengths. Furthermore, the inclusion of an AlGaP window layer improved both open-circuit voltage and short wavelength IQE.
Experimental demonstration of deflection angle tuning in unidirectional fishnet metamaterials at millimeter-waves
Authors: Rodríguez-Ulibarri P. , Pacheco-Peña V. , Navarro-Cía M. , Serebryannikov A. E. , Beruete M.
Published: February 2015

Asymmetric transmission enables high forward-to-backward transmission contrast in the Lorentz reciprocal framework, so that it is envisioned to be a backbone of future practical devices with strong directional selectivity. In this letter, we experimentally demonstrate efficient tuning and sign-switching capabilities of the deflection angle by varying the incidence angle and/or frequency in the unidirectional regime of a compact and simple structure comprising a stack of a fishnet metamaterial and a dielectric grating. The entire device operates at frequencies ranging from 45 to 75 GHz and has a total thickness of 0.77λ0 at 60 GHz.
Estimation of dietary selenium requirement for Chinese egg-laying ducks
Authors: Chen W. , Zhang H. X. , Wang S. , Ruan D. , Xie X. Z. , Yu D. Q. , Lin Y. C.
Published: February 2015

The purpose of this study was to estimate the selenium (Se) requirement of egg-laying ducks based on daily egg production and the selenoprotein glutathione peroxidase (Gpx). Five-hundred and forty laying ducks were divided into six treatments, each containing six replicates of 15 ducks. The birds were caged individually and received a Se-deficient basal diet (0.04 mg/kg) or diets supplemented with 0.08, 0.16, 0.24, 0.32, 0.40 mg/kg Se (as sodium selenite) for 6 months. The experiment consisted of two periods: an early-laying period of 2 months and the peak-laying period of 4 months. Egg production and feed intake were recorded daily. At the end of the experiment, blood samples were drawn for determination of Gpx activity in plasma (Gpx3) and in erythrocytes (Gpx1). Hepatic Gpx1 activity and relative expression of Gpx1 mRNA were also determined. Eggs (n = 6) were sampled for quality determination and Se content at the end of the experiment. The activities of plasma Gpx3, erythrocyte Gpx1 and liver Gpx1 increased in a quadratic manner (P < 0.001) with increasing supplemental Se. The mRNA abundance of hepatic Gpx1 increased linearly (P < 0.001) with dietary Se supplementation. Egg shell thickness was significantly reduced in the ducks fed 0.44 mg Se/kg (P < 0.05), indicating that higher dietary Se tends to compromise egg shell quality. Yolk and albumen contents of Se increased linearly (P < 0.0001) with dietary Se supplementation. Using quadratic broken line models, the Se requirement for daily egg production was 0.18 mg/kg for early-laying ducks and 0.24 mg/kg for peak-laying ducks; for optimal function of Gpx (peak-laying ducks), it was 0.37 mg Se/kg.
Effect of fitting sheep covers and injection of a mineral supplement on the brightness, clean colour and photostability of wool grown by grazing Merino sheep
Authors: Hatcher S. , Preston J. W. V.
Published: February 2015

Wethers sourced from a Merino genetic resource flock, selected on the basis of their measured wool clean colour at 2 years of age, were stratified on the basis of clean colour and allocated to one of four treatment groups in a 2 × 2 factorial design. The aim was to investigate the effect of coating the fleece and administration of a commercial mineral supplement on brightness, clean colour and photostability over a 12-month period when run on the Central Tablelands of New South Wales. Coating the fleece significantly improved both the brightness and clean colour of the fleece (P<0.001, by 4 and 0.5 T units, respectively), but had no effect on the photostability of the two traits. The mineral supplement had no significant impact on the colour or photostability traits and there was no evidence of an interaction between coating the fleece and the mineral supplement. Although the improvements in brightness and colour arising from coating the fleece complemented the predicted responses to genetic selection for these two traits, the combined effect would not be sufficient to replace the routine use of oxidative bleaching during processing.
Situated learning, post-migrant youth and ludic spaces in diverse urban environments in Italy
Authors: Zoletto Davide
Published: February 2015

The aim of this article is to offer introductory theoretical arguments in order to research the role that urban ludic spaces play in post-migrants' everyday processes of situated learning. I discuss how situated learning processes are embedded in everyday webs of relationships, with special reference to spatial construction of intersectionality within power laden spaces affecting the way in which communities of practice develop in urban areas. I draw on results from a previous research carried out in diverse neighbourhoods of central and north-east Italian cities as an example of the way in which public playgrounds could be laden by power and could in this way affect the opportunities to share everyday practices and to build up a community of practices in non-formal and informal learning environments.
Maximal varieties and the local Langlands correspondence for 𝐺𝐿(𝑛)
Authors: Boyarchenko Mitya , Weinstein Jared
Published: February 2015

The cohomology of the Lubin-Tate tower is known to realize the local Langlands correspondence forGL(n)GL(n)over a nonarchimedean local field. In this article we make progress toward a purely local proof of this fact. To wit, we find a family of formal schemesV\mathcal {V}such that the generic fiber ofV\mathcal {V}is isomorphic to an open subset of Lubin-Tate space at infinite level, and such that the middle cohomology of the special fiber ofV\mathcal {V}realizes the local Langlands correspondence for a broad class of supercuspidals (those whose Weil parameters are induced from an unramified degreennextension). The special fiber ofV\mathcal {V}is related to an interesting varietyXX, defined over a finite field, which is “maximal” in the sense that the number of rational points ofXXis the largest possible among varieties with the same Betti numbers asXX. The varietyXXis derived from a certain unipotent algebraic group, in an analogous manner as Deligne-Lusztig varieties are derived from reductive algebraic groups.
The inclusion problem for mixed norm spaces
Authors: Grey Wayne , Sinnamon Gord
Published: February 2015

Given two mixed norm Lebesgue spaces on an

n
n

-fold product of arbitrary

σ
\sigma

-finite measure spaces, is one contained in the other? If so, what is the norm of the inclusion map? These questions are answered completely for a large range of Lebesgue indices and all measure spaces. When the measure spaces are atomless, both questions are settled for all indices. When the measure spaces are not purely atomic, the first question is settled for all indices. Some complete and some partial results are given in the remaining cases, but a wide variety of behaviour is observed. In particular, the norm problem for purely atomic measure spaces is seen to be intractable for certain ranges of the Lebesgue indices; it is equivalent to an optimization problem that includes a known NP-hard problem as a special case.
Local maps and the representation theory of operator algebras
Authors: Katsoulis Elias
Published: February 2015

Using representation theory techniques we prove that various spaces of derivations or one-sided multipliers over certain operator algebras are reflexive. A sample result: any bounded local derivation (local left multiplier) on an automorphic semicrossed product

C
(
Ω
)

×

σ

Z

+

C(\Omega ) \times _{\sigma } \mathbb {Z}^{+}

is a derivation (resp. left multiplier). In the process we obtain various results of independent interest. In particular, we show that the finite dimensional nest representations of the tensor algebra of a topological graph separate points.
Knowledge and Awareness of Acute Human Immunodeficiency Virus Infection Among Mobile App-Using Men Who Have Sex With Men: A Missed Public Health Opportunity
Authors: Siegler Aaron J. , Sanchez Travis , Sineath R. Craig , Grey Jeremy , Kahle Erin , Sullivan Patrick S.
Published: February 2015

In a national online survey, we assessed awareness and knowledge of acute human immunodeficiency virus (HIV) infection manifestation among 1748 men who have sex with men (MSM). Only 39% of respondents were aware that acute HIV infection may be accompanied by symptoms. Education and increased access to acute HIV testing may facilitate MSM to appropriately seek acute HIV testing.
The photospheric Poynting flux and coronal heating
Authors: Welsch Brian T.
Published: February 2015

Some models of coronal heating suppose that convective motions at the photosphere shuffle the footpoints of coronal magnetic fields and thereby inject sufficient magnetic energy upward to account for observed coronal and chromospheric energy losses in active regions. Using high-resolution observations of plage magnetic fields made with the Solar Optical Telescope aboard the Hinode satellite, we investigate this idea by estimating the upward transport of magnetic energy—the vertical Poynting flux, Sz—across the photosphere in a plage region. To do so, we combine the following: (i) estimates of photospheric horizontal velocities, vh, determined by local correlation tracking applied to a sequence of line-of-sight magnetic field maps from the Narrowband Filter Imager, with (ii) a vector magnetic field measurement from the SpectroPolarimeter. Plage fields are ideal observational targets for estimating energy injection by convection, because they are (i) strong enough to be measured with relatively small uncertainties, (ii) not so strong that convection is heavily suppressed (as within umbrae), and (iii) unipolar, so Sz in plage is not influenced by mixed-polarity processes (e.g., flux emergence) unrelated to heating in stable, active-region fields. In this plage region, we found that the average Sz varied in space, but was positive (upward) and sufficient to explain coronal heating, with values near (5 ± 1) × 107 erg cm−2 s−1. We find the energy input per unit magnetic flux to be on the order of 105 erg s−1 Mx−1. A comparison of intensity in a Ca ii image co-registered with one plage magnetogram shows stronger spatial correlations with both total field strength and unsigned vertical field, |Bz|, than either Sz or horizontal flux density, Bh. The observed Ca ii brightness enhancement, however, probably contains a strong contribution from a near-photosphere hot-wall effect, which is unrelated to heating in the solar atmosphere.
Unraveling the Etiology of North American Grapevine Yellows (NAGY): Novel NAGY Phytoplasma Sequevars Related to ‘Candidatus Phytoplasma pruni’
Authors: Davis Robert E. , Dally Ellen L. , Zhao Yan , Lee Ing-Ming , Wei Wei , Wolf Tony K. , Beanland LeAnn , LeDoux Douglas G. , Johnson David A. , Fiola Joseph A. , Walter-Peterson Hans , Dami Imed , Chien Mark
Published: February 2015

North American grapevine yellows (NAGY) disease has sometimes been attributed to infection of Vitis vinifera L. by Prunus X-disease phytoplasma (‘Candidatus Phytoplasma pruni’) but this attribution may not be fully adequate. In this study, phytoplasma strains related to ‘Ca. Phytoplasma pruni’ were found in NAGY-diseased grapevines in Maryland, Pennsylvania, Virginia, Ohio, Missouri, and New York State. Based on restriction fragment length polymorphism analysis of 16S ribosomal RNA gene (16S rDNA) sequences, the strains (termed NAGYIII strains) were classified in group 16SrIII (X-disease group) but they contained a recognition site for the restriction endonuclease MseI that is not present in the 16S rDNA of ‘Ca. Phytoplasma pruni’. The 16S rDNA of the strains differed by three or four nucleotides from that of ‘Ca. Phytoplasma pruni’, indicating that they belonged to two novel 16S rDNA sequevars, designated NAGYIIIα and NAGYIIIβ. Both sequevars differed from ‘Ca. Phytoplasma pruni’ by a single base in each of three regions corresponding to species-unique (signature) sequences described for ‘Ca. Phytoplasma pruni’. Phylogenetic analyses of 16S rRNA genes and SecY proteins, and single-nucleotide polymorphism analyses of secY and ribosomal protein genes, further distinguished the two grapevine sequevar lineages from one another and from ‘Ca. Phytoplasma pruni’. The NAGYIIIα and NAGYIIIβ sequevars also differed from ‘Ca. Phytoplasma pruni’ in regions of the folded SecY protein that are predicted to be near or exposed at the outer surface of the phytoplasma membrane. No evidence indicated that diseased grapevines contained any phytoplasma strain conforming to ‘Ca. Phytoplasma pruni’ sensu stricto. Because the NAGYIII sequevars have not been reported in X-disease, a question is raised as to whether NAGYIII and Prunus X-disease are caused by different phytoplasma genotypes.
Optimal chest compression rate in cardiopulmonary resuscitation: a prospective, randomized crossover study using a manikin model
Authors: Lee Seong Hwa , Ryu Ji Ho , Min Mun Ki , Kim Yong In , Park Maeng Real , Yeom Seok Ran , Han Sang Kyoon , Park Seong Wook
Published: February 2015

Objectives

When performing cardiopulmonary resuscitation (CPR), the 2010 American Heart Association guidelines recommend a chest compression rate of at least 100 min−1, whereas the 2010 European Resuscitation Council guidelines recommend a rate of between 100 and 120 min−1. The aim of this study was to examine the rate of chest compression that fulfilled various quality indicators, thereby determining the optimal rate of compression.

Methods

Thirty-two trainee emergency medical technicians and six paramedics were enrolled in this study. All participants had been trained in basic life support. Each participant performed 2 min of continuous compressions on a skill reporter manikin, while listening to a metronome sound at rates of 100, 120, 140, and 160 beats/min, in a random order. Mean compression depth, incomplete chest recoil, and the proportion of correctly performed chest compressions during the 2 min were measured and recorded.

Results

The rate of incomplete chest recoil was lower at compression rates of 100 and 120 min−1 compared with that at 160 min−1 (P=0.001). The numbers of compressions that fulfilled the criteria for high-quality CPR at a rate of 120 min−1 were significantly higher than those at 100 min−1 (P=0.016).

Conclusion

The number of high-quality CPR compressions was the highest at a compression rate of 120 min−1, and increased incomplete recoil occurred with increasing compression rate. However, further studies are needed to confirm the results.
Bonobos and chimpanzees exhibit human-like framing effects
Authors: Krupenye Christopher , Rosati Alexandra G. , Hare Brian
Published: February 2015

Humans exhibit framing effects when making choices, appraising decisions involving losses differently from those involving gains. To directly test for the evolutionary origin of this bias, we examined decision-making in humans' closest living relatives: bonobos (
Pan paniscus
) and chimpanzees (
Pan troglodytes
). We presented the largest sample of non-humans to date (
n
= 40) with a simple task requiring minimal experience. Apes made choices between a ‘framed’ option that provided preferred food, and an alternative option that provided a constant amount of intermediately preferred food. In the
gain condition
, apes experienced a positive ‘gain’ event in which the framed option was initially presented as one piece of food but sometimes was augmented to two. In the
loss condition
, apes experienced a negative ‘loss' event in which they initially saw two pieces but sometimes received only one. Both conditions provided equal pay-offs, but apes chose the framed option more often in the positive ‘gain’ frame. Moreover, male apes were more susceptible to framing than were females. These results suggest that some human economic biases are shared through common descent with other apes and highlight the importance of comparative work in understanding the origins of individual differences in human choice.
Role of sources and temporal sinks in a marine amphipod
Authors: Munguia Pablo
Published: February 2015

Spatially structured habitats challenge populations to have positive growth rates and species often rely on dispersing propagules to occupy habitats outside their fundamental niche. Most marine species show two main life stages, a dispersing stage and a sedentary stage affecting distribution and abundance patterns. An experimental study on
Corophium acherusicum,
a colonial tube-building amphipod, showed the strong influence that a source population can have on new habitats. More importantly, this study shows the effect of temporal sinks where newly established populations can show reduced growth rates if the propagule supply from a source is removed. Sink populations had a reduction in abundance and became male-biased as females left colonies. The consequences arising from short-term dispersal and temporal sinks could be due to different selection pressures at the source and sink populations. These consequences can become reflected in long-term dynamics of marine populations if we shift focus to non-random dispersal models incorporating behaviour and stage-dependent dispersal.
Effect of nutrients and salinity pulses on biomass and growth of
Vallisneria americana
in lower St Johns River, FL, USA
Authors: Boustany Ronald G. , Michot Thomas C. , Moss Rebecca F.
Published: February 2015

We determined the interactive effects of nutrient loading and salinity pulsing on
Vallisneria americana
Michx., the dominant submerged aquatic vegetation species in the lower St Johns River (LSJR), FL, USA, and its associated algal community. Five hundred and ninety 6-inch diameter intact plant plugs of
Vallisneria
were collected from the LSJR in March 2003 and transported to US Geological Survey mesocosm facilities in Lafayette, LA, USA. A 3×3 experimental design consisting of three nutrient levels (control, 1/3 control and 3× control) and three salinity pulsing regimes (no pulse, 1-pulse at 18 ppt and 2-pulse at 12 and 18 ppt) was implemented with three replicates per treatment for a total of 27 experimental tanks. Salinity pulsing significantly reduced all measured
Vallisneria
growth parameters including above- and below-ground biomass, areal productivity and leaf area index. Nutrient levels had little effect on plants subjected to salinity pulses, but in non-salinity pulse treatments we observed higher mean macrophyte biomass in the low-nutrient loading treatments. Macroalgal components (epiphytes and surface algal mats) were not significantly different ( 
p
=0.2998 and
p
=0.2444, respectively), but water column chlorophyll
a
(phytoplankton) was significantly higher ( 
p
<0.0001) in all salinity pulse treatments except for the 1-pulse, low-nutrient treatment. A single salinity pulse at 18 ppt resulted in 22% pot mortality and two consecutive pulses of 18 and 12 ppt resulted in an additional 14% mortality. Individual leaves and ramets lost 59.7% and 67.8%, respectively, in the combined salinity pulse treatments. Nutrient loading tends to have a long-term effect on
Vallisneria
through complex community interactions while salinity pulsing frequency and intensity has an immediate and direct influence on growth and distribution.
Prevalent endosymbiont zonation shapes the depth distributions of scleractinian coral species
Authors: Bongaerts Pim , Carmichael Margaux , Hay Kyra B. , Tonk Linda , Frade Pedro R. , Hoegh-Guldberg Ove
Published: February 2015

Bathymetric distributions of photosynthetic marine invertebrate species are relatively well studied, however the importance of symbiont zonation (i.e. hosting of distinct algal endosymbiont communities over depth) in determining these depth distributions still remains unclear. Here, we assess the prevalence of symbiont zonation in tropical scleractinian corals by genotyping the
Symbiodinium
of the 25 most common species over a large depth range (down to 60 m) on a Caribbean reef. Symbiont depth zonation was found to be common on a reef-wide scale (11 out of 25 coral species), and a dominant feature in species with the widest depth distributions. With regards to reproductive strategy, symbiont zonation was more common in broadcasting species, which also exhibited a higher level of polymorphism in the symbiont zonation (i.e. number of different
Symbiodinium
profiles involved). Species with symbiont zonation exhibited significantly broader depth distributions than those without, highlighting the role of symbiont zonation in shaping the vertical distributions of the coral host. Overall, the results demonstrate that coral reefs can consist of highly structured communities over depth when considering both the coral host and their obligate photosymbionts, which probably has strong implications for the extent of connectivity between shallow and mesophotic habitats.
Concurrent atomistic and continuum simulation of bi-crystal strontium titanate with tilt grain boundary
Authors: Yang Shengfeng , Chen Youping
Published: February 2015

In this paper, we present the development of a concurrent atomistic–continuum (CAC) methodology for simulation of the grain boundary (GB) structures and their interaction with other defects in ionic materials. Simulation results show that the CAC simulation allows a smooth passage of cracks through the atomistic–continuum interface without the need for additional constitutive rules or special numerical treatment; both the atomic-scale structures and the energies of the four different [001] tilt GBs in bi-crystal strontium titanate obtained by CAC compare well with those obtained by existing experiments and density function theory calculations. Although 98.4% of the degrees of freedom of the simulated atomistic system have been eliminated in a coarsely meshed finite-element region, the CAC results, including the stress–strain responses, the GB–crack interaction mechanisms and the effect of the interaction on the fracture strength, are comparable with that of all-atom molecular dynamics simulation results. In addition, CAC simulation results show that the GB–crack interaction has a significant effect on the fracture behaviour of bi-crystal strontium titanate; not only the misorientation angle but also the atomic-level details of the GB structure influence the effect of the GB on impeding crack propagation.
Inclusive fitness and differential productivity across the life course determine intergenerational transfers in a small-scale human society
Authors: Hooper Paul L. , Gurven Michael , Winking Jeffrey , Kaplan Hillard S.
Published: February 2015

Transfers of resources between generations are an essential element in current models of human life-history evolution accounting for prolonged development, extended lifespan and menopause. Integrating these models with Hamilton's theory of inclusive fitness, we predict that the interaction of biological kinship with the age-schedule of resource production should be a key driver of intergenerational transfers. In the empirical case of Tsimane’ forager–horticulturalists in Bolivian Amazonia, we provide a detailed characterization of net transfers of food according to age, sex, kinship and the net need of donors and recipients. We show that parents, grandparents and siblings provide significant net downward transfers of food across generations. We demonstrate that the extent of provisioning responds facultatively to variation in the productivity and demographic composition of families, as predicted by the theory. We hypothesize that the motivation to provide these critical transfers is a fundamental force that binds together human nuclear and extended families. The ubiquity of three-generational families in human societies may thus be a direct reflection of fundamental evolutionary constraints on an organism's life-history and social organization.
A pan-cancer signature of neutral tumor evolution
Authors: Sottoriva Andrea , Graham Trevor A.
Published: February 2015

Despite extraordinary efforts to profile cancer genomes on a large scale, interpreting the vast amount of genomic data in the light of cancer evolution and in a clinically relevant manner remains challenging. Here we demonstrate that cancer next-generation sequencing data is dominated by the signature of growth governed by a power-law distribution of mutant allele frequencies. The power-law signature is common to multiple tumor types and is a consequence of the effectively-neutral evolutionary dynamics that underpin the evolution of a large proportion of cancers, giving rise to the abundance of mutations responsible for intra-tumor heterogeneity. Importantly, the law allows the measurement, in each individual cancer, of thein vivomutation rate and the timing of mutations with remarkable precision. This result provides a new way to interpret cancer genomic data by considering the physics of tumor growth in a way that is both patient-specific and clinically relevant.
Detection and phasing of single base de novo mutations in biopsies from human in vitro fertilized embryos by advanced whole-genome sequencing
Authors: Peters Brock A. , Kermani Bahram G. , Alferov Oleg , Agarwal Misha R. , McElwain Mark A. , Gulbahce Natali , Hayden Daniel M. , Tang Y. Tom , Zhang Rebecca Yu , Tearle Rick , Crain Birgit , Prates Renata , Berkeley Alan , Munné Santiago , Drmanac Radoje
Published: February 2015

Currently, the methods available for preimplantation genetic diagnosis (PGD) of in vitro fertilized (IVF) embryos do not detect de novo single-nucleotide and short indel mutations, which have been shown to cause a large fraction of genetic diseases. Detection of all these types of mutations requires whole-genome sequencing (WGS). In this study, advanced massively parallel WGS was performed on three 5- to 10-cell biopsies from two blastocyst-stage embryos. Both parents and paternal grandparents were also analyzed to allow for accurate measurements of false-positive and false-negative error rates. Overall, >95% of each genome was called. In the embryos, experimentally derived haplotypes and barcoded read data were used to detect and phase up to 82% of de novo single base mutations with a false-positive rate of about one error per Gb, resulting in fewer than 10 such errors per embryo. This represents a ∼100-fold lower error rate than previously published from 10 cells, and it is the first demonstration that advanced WGS can be used to accurately identify these de novo mutations in spite of the thousands of false-positive errors introduced by the extensive DNA amplification required for deep sequencing. Using haplotype information, we also demonstrate how small de novo deletions could be detected. These results suggest that phased WGS using barcoded DNA could be used in the future as part of the PGD process to maximize comprehensiveness in detecting disease-causing mutations and to reduce the incidence of genetic diseases.
“Self” and “Non-Self” in the Control of Phytoalexin Biosynthesis: Plant Phospholipases A2 with Alkaloid-Specific Molecular Fingerprints
Authors: Heinze Michael , Brandt Wolfgang , Marillonnet Sylvestre , Roos Werner
Published: February 2015

The overproduction of specialized metabolites requires plants to manage the inherent burdens, including the risk of self-intoxication. We present a control mechanism that stops the expression of phytoalexin biosynthetic enzymes by blocking the antecedent signal transduction cascade. Cultured cells of Eschscholzia californica (Papaveraceae) and Catharanthus roseus (Apocynaceae) overproduce benzophenanthridine alkaloids and monoterpenoid indole alkaloids, respectively, in response to microbial elicitors. In both plants, an elicitor-responsive phospholipase A2 (PLA2) at the plasma membrane generates signal molecules that initiate the induction of biosynthetic enzymes. The final alkaloids produced in the respective plant inhibit the respective PLA, a negative feedback that prevents continuous overexpression. The selective inhibition by alkaloids from the class produced in the “self” plant could be transferred to leaves of Nicotiana benthamiana via recombinant expression of PLA2. The 3D homology model of each PLA2 displays a binding pocket that specifically accommodates alkaloids of the class produced by the same plant, but not of the other class; for example, C. roseus PLA2 only accommodates C. roseus alkaloids. The interaction energies of docked alkaloids correlate with their selective inhibition of PLA2 activity. The existence in two evolutionary distant plants of phospholipases A2 that discriminate “self-made” from “foreign” alkaloids reveals molecular fingerprints left in signal enzymes during the evolution of species-specific, cytotoxic phytoalexins.
Crystal structure of 5-(1,3-dithian-2-yl)-2H-1,3-benzodioxole
Authors: Zukerman-Schpector Julio , Caracelli Ignez , Stefani Hélio A. , Gozhina Olga , Tiekink Edward R. T.
Published: February 2015

In the title compound, C11H12O2S2, two independent but virtually superimposable molecules,AandB, comprise the asymmetric unit. In each molecule, the 1,3-dithiane ring has a chair conformation with the 1,4-disposed C atoms being above and below the plane through the remaining four atoms. The substituted benzene ring occupies an equatorial position in each case and forms dihedral angles of 85.62 (9) (moleculeA) and 85.69 (8)° (moleculeB) with the least-squares plane through the 1,3-dithiane ring. The difference between the molecules rests in the conformation of the five-membered 1,3-dioxole ring which is an envelope in moleculeA(the methylene C atom is the flap) and almost planar in moleculeB(r.m.s. deviation = 0.046 Å). In the crystal, molecules ofAself-associate into supramolecular zigzag chains (generated by glide symmetry along thecaxis)viamethylene C—H...π interactions. Molecules ofBform similar chains. The chains pack with no specific directional intermolecular interactions between them.
Crystal structure of 2-(3-nitrophenyl)-1,3-dithiane
Authors: Caracelli Ignez , Zukerman-Schpector Julio , Stefani Hélio A. , Gozhina Olga , Tiekink Edward R. T.
Published: February 2015

In the title compound, C10H11NO2S2, the 1,3-dithiane ring has a chair conformation with the 1,4-disposed C atoms being above and below the remaining four atoms. The nitrobenzene substituent occupies an equatorial position and forms a dihedral angle of 88.28 (5)° with the least-squares plane through the 1,3-dithiane ring. The nitro group is twisted out of the plane of the benzene ring to which it is connected, forming a dihedral angle of 10.12 (3)°. In the crystal, molecules aggregate into supramolecular zigzag chains (glide symmetry along thecaxis)vianitro–benzene N—O...π [N—O...Cg(benzene) = 3.4279 (18) Å and angle at O = 93.95 (11)°] interactions. The chains pack with no specific intermolecular interactions between them.
Impact of consumer socialization on soft drink consumption and mediating role of consumer generational behavior
Authors: Shahzad Faisal , Khattak Jamshed Khan , Khattak Mobeen Jamshed , Shahzad Fahad
Published: February 2015

Purpose

– The purpose of this paper is to explore how consumers’ socialization influences soft drink consumption behavior in Pakistan. Since consumer socialization has long been considered but it is important to understand whether the extent of consumer socialization in terms of soft drink consumption influences consumer behavior by taking into consideration consumer cohorts.

Design/methodology/approach

– The quantitative research is based on consumer survey method by using Likert scale questionnaire. Convenience sampling technique with a sample size of 637 is used. Data are analyzed by using cronbach α, ANOVA, correlation and multiple regressions.

Findings

– Overall, the findings maintain the impact of consumer socialization on soft drink consumption. Such influence of consumer socialization through social media, cultural groups and social groups encourages soft drink socialization behavior. Additionally there is also an evidence of mediating role of consumer generational behavior in soft drink consumption.

Research limitations/implications

– The results of this paper extend knowledge of how consumer socialization affects soft drink consumption behavior and provide important insights into how consumer cohorts should be targeted. The Chosen research approach is a limitation of the study.

Practical implications

– The results are of value to academic researchers, soft drink industry practitioners in a way that it will help them to portray marketing and advertising activities by taking into consideration consumer cohorts behavior.

Social implications

– This paper addresses an untapped issue on how cohorts socialization at different social setting impact on consumer soft drink consumption behavior.

Originality/value

– This paper fulfills a recognized need to study soft drink socialization in terms of cohort’s behavior.
ICT product diffusion in US and Korean markets
Authors: Lee Sang-Gun , Yang Chang-Gyu , Lee Eui-Bang
Published: February 2015

Purpose

– The purpose of this paper is to identify how adoption drivers change before and after key milestones of ICT product adoption (i.e. critical mass point (CMP) (adoption rate 16 percent), market saturation point (MSP) (50 percent) and new generation release point (NGRP)) based on actual subscriber data of the mobile communications industry that represents the ICT market, so that it has implications for the rejuvenation of ICT product adoption that has rarely been addressed in earlier studies.

Design/methodology/approach

– This study examined the overall characteristics of ICT product diffusion by tracking the actual patterns of US and Korean mobile market subscribers using the Bass diffusion model.

Findings

– This study found that innovation effects gain influences on ICT product diffusion after CMP, MSP and NGRP; imitators are becoming innovators by repeated rejuvenation experiences; and cultural differences have significant influences on imitators’ ICT product adoption, but not on innovators.

Originality/value

– These findings imply that rejuvenation enabled by technology innovation is a key success strategy to dominate the ICT market where the number of innovators, who have strong desires for new generation products, is constantly growing.