bluuebunny/crossref_metadata_2025 huggingface dataset:
Attenuated total reflectance Fourier-transform infrared spectroscopic investigation of silicon heterojunction solar cells
Authors: Holovský Jakub , De Wolf Stefaan , Jiříček Petr , Ballif Christophe
Published: July 2015

Silicon heterojunction solar cells critically depend on the detailed properties of their amorphous/crystalline silicon interfaces. We report here on the use of attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy to gain precise insight into the vibrational properties of the surfaces and ultrathin layers present in such solar cells. We fabricate ATR prisms from standard silicon wafers similar to those used for device fabrication. In this fashion, we acquire very-high sensitivity FTIR information on device-relevant structures. Our method has no requirement for minimum layer thickness, enabling the study of the impact of the different fabrication process steps on the film microstructure. We discuss the necessary requirements for the method implementation and give a comprehensive overview of all observed vibration modes. In particular, we study vibrational signatures of Si–HX, Si–HX(SiYOZ), B–H, hydroxyl groups, and hydrocarbons on the Si(111) surface. We observe subtle effects in the evolution of the chemical state of the surface during sample storage and process-related wafer handling and discuss their effect on the electronic properties of the involved interfaces.
Formation of strained interfaces in AlSb/InAs multilayers grown by molecular beam epitaxy for quantum cascade lasers
Authors: Nicolaï J. , Warot-Fonrose B. , Gatel C. , Teissier R. , Baranov A. N. , Magen C. , Ponchet A.
Published: July 2015

Structural and chemical properties of InAs/AlSb interfaces have been studied by transmission electron microscopy. InAs/AlSb multilayers were grown by molecular beam epitaxy with different growth sequences at interfaces. The out-of-plane strain, determined using high resolution microscopy and geometrical phase analysis, has been related to the chemical composition of the interfaces analyzed by high angle annular dark field imaging. Considering the local strain and chemistry, we estimated the interface composition and discussed the mechanisms of interface formation for the different growth sequences. In particular, we found that the formation of the tensile AlAs-type interface is spontaneously favored due to its high thermal stability compared to the InSb-type interface. We also showed that the interface composition could be tuned using an appropriate growth sequence.
Stepwise vs concerted excited state tautomerization of 2-hydroxypyridine: Ammonia dimer wire mediated hydrogen/proton transfer
Authors: Esboui Mounir
Published: July 2015

The stepwise and concerted excited state intermolecular proton transfer (PT) and hydrogen transfer (HT) reactions in 2-hydroxypyridine-(NH3)2 complex in the gas phase under Cs symmetry constraint and without any symmetry constraints were performed using quantum chemical calculations. It shows that upon excitation, the hydrogen bonded in 2HP-(NH3)2 cluster facilitates the releasing of both hydrogen and proton transfer reactions along ammonia wire leading to the formation of the 2-pyridone tautomer. For the stepwise mechanism, it has been found that the proton and the hydrogen may transfer consecutively. These processes are distinguished from each other through charge translocation analysis and the coupling between the motion of the proton and the electron density distribution along ammonia wire. For the complex under Cs symmetry, the excited state HT occurs on the A″(1πσ∗) and A′(1nσ∗) states over two accessible energy barriers along reaction coordinates, and excited state PT proceeds mainly through the A′(1ππ∗) and A″(1nπ∗) potential energy surfaces. For the unconstrained complex, potential energy profiles show two 1ππ∗-1πσ∗ conical intersections along enol → keto reaction path indicating that proton and H atom are localized, respectively, on the first and second ammonia of the wire. Moreover, the concerted excited state PT is competitive to take place with the stepwise process, because it proceeds over low barriers of 0.14 eV and 0.11 eV with respect to the Franck-Condon excitation of enol tautomer, respectively, under Cs symmetry and without any symmetry constraints. These barriers can be probably overcome through tunneling effect.
Stochastic acceleration of ions driven by Pc1 wave packets
Authors: Khazanov G. V. , Sibeck D. G. , Tel'nikhin A. A. , Kronberg T. K.
Published: July 2015

The stochastic motion of protons and He+ ions driven by Pc1 wave packets is studied in the context of resonant particle heating. Resonant ion cyclotron heating typically occurs when wave powers exceed 10−4 nT2/Hz. Gyroresonance breaks the first adiabatic invariant and energizes keV ions. Cherenkov resonances with the electrostatic component of wave packets can also accelerate ions. The main effect of this interaction is to accelerate thermal protons to the local Alfven speed. The dependencies of observable quantities on the wave power and plasma parameters are determined, and estimates for the heating extent and rate of particle heating in these wave-particle interactions are shown to be in reasonable agreement with known empirical data.
Analysis of diverging effective mass extracted from thermoelectric power across the metal–insulator transition in VO2
Authors: Kang Manil , Kim Sok Won , Ryu Ji-Wook
Published: July 2015

In order to reveal the electron-electron correlation (interaction) effect in a Mott insulator VO2, we measured the temperature dependence of the thermopower, Hall effect, and Raman spectra in VO2 films and extracted the diverging effective mass from the thermoelectric behavior in the metal-insulator transition (MIT) region, using a combination of the thermopower formula for two-dimensional electron system and the extended Brinkman-Rice (EBR) model explaining the correlation effect. The temperature dependence of the measured diverging thermoelectric power is closely fitted by the band-filling (ρ) dependent effective mass m*/m=1/(1−ρ4) given in the EBR model. The diverging behavior is the effect of measurement and analyzed as the percolation phenomenon increasing the metal region with increasing temperature. The true effective mass in the metal region is regarded as constant regardless of ρ. The true correlation strength κBR in the BR model deduced by extrapolation near ρ=1 is evaluated as κBR > 0.92. The Raman spectra showed decoupling between the MIT and the structural phase transition associated with lattice distortion induced by the electron-phonon interaction. Thus, we conclude the MIT in VO2 as a first-order Mott MIT induced by strong correlation regardless of the electron-phonon interaction.
Mechanical behavior of a composite interface: Calcium-silicate-hydrates
Authors: Palkovic Steven D. , Moeini Sina , Yip Sidney , Büyüköztürk Oral
Published: July 2015

The generalized stacking fault (GSF) is a conceptual procedure historically used to assess shear behavior of defect-free crystalline structures through molecular dynamics or density functional theory simulations. We apply the GSF technique to the spatially and chemically complex quasi-layered structure of calcium-silicate-hydrates (C-S-H), the fundamental nanoscale binder within cementitious materials. A failure plane is enforced to calculate the shear traction-displacement response along a composite interface containing highly confined water molecules, hydroxyl groups, and calcium ions. GSF simulations are compared with affine (homogeneous) shear simulations, which allow strain to localize naturally in response to the local atomic environment. Comparison of strength and deformation behavior for the two loading methods shows the composite interface controls bulk shear deformation. Both models indicate the maximum shear strength of C-S-H exhibits a normal-stress dependency typical of cohesive-frictional materials. These findings suggest the applicability of GSF techniques to inhomogeneous structures and bonding environments, including other layered systems such as biological materials containing organic and inorganic interfaces.
Energy transfer upon collision of selectively excited CO2 molecules: State-to-state cross sections and probabilities for modeling of atmospheres and gaseous flows
Authors: Lombardi A. , Faginas-Lago N. , Pacifici L. , Grossi G.
Published: July 2015

Carbon dioxide molecules can store and release tens of kcal/mol upon collisions, and such an energy transfer strongly influences the energy disposal and the chemical processes in gases under the extreme conditions typical of plasmas and hypersonic flows. Moreover, the energy transfer involving CO2 characterizes the global dynamics of the Earth-atmosphere system and the energy balance of other planetary atmospheres. Contemporary developments in kinetic modeling of gaseous mixtures are connected to progress in the description of the energy transfer, and, in particular, the attempts to include non-equilibrium effects require to consider state-specific energy exchanges. A systematic study of the state-to-state vibrational energy transfer in CO2 + CO2 collisions is the focus of the present work, aided by a theoretical and computational tool based on quasiclassical trajectory simulations and an accurate full-dimension model of the intermolecular interactions. In this model, the accuracy of the description of the intermolecular forces (that determine the probability of energy transfer in molecular collisions) is enhanced by explicit account of the specific effects of the distortion of the CO2 structure due to vibrations. Results show that these effects are important for the energy transfer probabilities. Moreover, the role of rotational and vibrational degrees of freedom is found to be dominant in the energy exchange, while the average contribution of translations, under the temperature and energy conditions considered, is negligible. Remarkable is the fact that the intramolecular energy transfer only involves stretching and bending, unless one of the colliding molecules has an initial symmetric stretching quantum number greater than a threshold value estimated to be equal to 7.
Dependence of the energy transfer to graphene on the excitation energy
Authors: Mackowski Sebastian , Kamińska Izabela
Published: July 2015

Fluorescence studies of natural photosynthetic complexes on a graphene layer demonstrate pronounced influence of the excitation wavelength on the energy transfer efficiency to graphene. Ultraviolet light yields much faster decay of fluorescence, with average efficiencies of the energy transfer equal to 87% and 65% for excitation at 405 nm and 640 nm, respectively. This implies that focused light changes locally the properties of graphene affecting the energy transfer dynamics, in an analogous way as in the case of metallic nanostructures. Demonstrating optical control of the energy transfer is important for exploiting unique properties of graphene in photonic and sensing architectures.
Highly efficient and two-photon excited stimulated Rayleigh-Bragg scattering in organic solutions
Authors: He Guang S. , Prasad Paras N. , Kannan Ramamurthi , Tan Loon-Seng
Published: July 2015

The properties of backward stimulated Rayleigh-Bragg scattering (SRBS) in three highly two-photon active AF-chromophores solutions in tetrahydrofuran (THF) have been investigated using 816-nm and 8-ns pump laser beam. The nonlinear reflectivity R, spectral structure, temporal behavior, and phase-conjugation capability of the backward SRBS output have been measured, respectively. Under the same experimental condition, the pump threshold for SRBS in three solution samples can be significantly (∼one order of magnitude) lower than that for stimulated Brillouin scattering (SBS) in the pure solvent (THF). With the optimized concentration value and at a moderate pump energy (∼1.5 mJ) level, the measured nonlinear reflectivity was R ≥ 35% for the 2 cm-long solution sample, while for the SBS from a pure solvent sample of the same length was R ≈ 4.7%. The peculiar features of very low pump threshold, no spectral shift, tolerant pump spectral linewidth requirement (≤1 cm−1), and phase-conjugation capability are favorable for those nonlinear photonics applications, such as highly efficiency phase-conjugation reflectors for high-brightness laser oscillator/amplifier systems, special imaging through turbid medium, self-adaptive remote optical sensing, as well as for optical rangefinder and lidar systems.
Semiconducting ZnSnxGe1−xN2 alloys prepared by reactive radio-frequency sputtering
Authors: Shing Amanda M. , Coronel Naomi C. , Lewis Nathan S. , Atwater Harry A.
Published: July 2015

We report on the fabrication and structural and optoelectronic characterization of II-IV-nitride ZnSnxGe1−xN2 thin-films. Three-target reactive radio-frequency sputtering was used to synthesize non-degenerately doped semiconducting alloys having <10% atomic composition (x = 0.025) of tin. These low-Sn alloys followed the structural and optoelectronic trends of the alloy series. Samples exhibited semiconducting properties, including optical band gaps and increasing in resistivities with temperature. Resistivity vs. temperature measurements indicated that low-Sn alloys were non-degenerately doped, whereas alloys with higher Sn content were degenerately doped. These films show potential for ZnSnxGe1−xN2 as tunable semiconductor absorbers for possible use in photovoltaics, light-emitting diodes, or optical sensors.
Coupling of dust acoustic and shear mode through velocity shear in a strongly coupled dusty plasma
Authors: Garai S. , Janaki M. S. , Chakrabarti N.
Published: July 2015

In the strongly coupled limit, the generalized hydrodynamic model shows that a dusty plasma, acquiring significant rigidity, is able to support a “shear” like mode. It is being demonstrated here that in presence of velocity shear gradient, this shear like mode gets coupled with the dust acoustic mode which is generated by the compressibility effect of the dust fluid due to the finite temperatures of the dust, electron, and ion fluids. In the local analysis, the dispersion relation shows that velocity shear gradient not only couples the two modes but is also responsible for the instabilities of that coupled mode which is confirmed by nonlocal analysis with numerical techniques.
Marangoni mixed convection flow with Joule heating and nonlinear radiation
Authors: Hayat Tasawar , Shaheen Uzma , Shafiq Anum , Alsaedi Ahmed , Asghar Saleem
Published: July 2015

Marangoni mixed convective flow of Casson fluid in a thermally stratified medium is addressed. Flow analysis has been carried out in presence of inclined magnetic field. Heat transfer analysis is discussed in the presence of viscous dissipation, Joule heating and nonlinear thermal radiation. The governing nonlinear partial differential equations are first converted into ordinary differential systems and then developed the convergent series solutions. Flow pattern with the influence of pertinent parameters namely the magnetic parameter, Casson fluid parameter, temperature ratio parameter, stratification parameter, Prandtl number, Eckert number and radiation parameter is investigated. Expression of local Nusselt number is computed and analyzed. It is found that the Nusselt number decreases by increasing magnetic parameter, temperature ratio parameter, angle of inclination and stratification parameter. Moreover the effect of buoyancy parameter on the velocity distribution is opposite in both the opposing and assisting flow phenomena. Thermal field and associated layer thickness are enhanced for larger radiation parameter.
A New Protocol for Total Synthesis of Natural Product Frutinone A and Its Derivatives
Authors: Lei Kang , Sun Dong-Wei , Tao Yuan-Yuan , Xu Xiao-Hua
Published: July 2015

A new protocol for total synthesis of natural product frutinone A was accomplished in three steps by using inexpensive 2′-hydroxyacetophenone as starting material. The key intermediate 3-(2-chlorobenzoyl)-4-hydroxycoumarin was synthesized in one pot through Baker–Venkataraman rearrangement of 2-acetylphenyl 2-chlorobenzoate followed by introduction of methyl chloroformate under basic conditions. Then, base-promoted intramolecular nucleophilic substitution reaction of 3-(2-chlorobenzoyl)-4-hydroxycoumarin provided frutinone A in excellent yield. The synthetic route features good yield, transition metal-free and mild reaction conditions, and high tolerance for functionality, thereby allowing easy substitutions around the frutinone A core.
Structural basis for methyl-donor–dependent and sequence-specific binding to tRNA substrates by knotted methyltransferase TrmD
Authors: Ito Takuhiro , Masuda Isao , Yoshida Ken-ichi , Goto-Ito Sakurako , Sekine Shun-ichi , Suh Se Won , Hou Ya-Ming , Yokoyama Shigeyuki
Published: July 2015

Significance

In bacterial tRNAs with the
36
GG
37
sequence, where positions 36 and 37 are, respectively, the third letter of the anticodon and 3′ adjacent to the anticodon, the modification of
N
1
-methylguanosine (m
1
G) at position 37 prevents +1 frameshifts on the ribosome. The m
1
G37 modification is introduced by the enzyme TrmD, which harbors a deep trefoil knot within the
S
-adenosyl-L-methionine (AdoMet)-binding site. We determined the crystal structure of the TrmD homodimer in complex with a substrate tRNA and an AdoMet analog. The structure revealed how TrmD, upon AdoMet binding in the trefoil knot, obtains the ability to bind the substrate tRNA, and interacts with G37 and G36 sequentially to transfer the methyl moiety of AdoMet to the N
1
position of G37.
Assessing the Relationship between Gulls Larus spp. and Pacific Salmon in Central California Using Radiotelemetry
Authors: Frechette Danielle , Osterback Ann-Marie K. , Hayes Sean A. , Moore Jonathan W. , Shaffer Scott A. , Pavelka Mark , Winchell Clark , Harvey James T.
Published: July 2015

Predation by marine birds has resulted in substantial losses to runs of Pacific salmon Oncorhynchus spp., in some cases necessitating management action. Recovery of PIT tags on a seabird breeding colony (Año Nuevo Island) indicated that western gulls Larus occidentalis prey upon federally listed Coho Salmon Oncorhynchus kisutch and steelhead O. mykiss in central California. Whereas salmonid populations in central California have decreased in recent decades, the western gull population on Año Nuevo Island has increased. We observed gulls Larus spp. within estuaries to document predation and used radiotelemetry to examine gull movement in relation to the availability of salmonids. During 2008 and 2009, observed predation events of out-migrating salmonids by gulls were rare; 21 events occurred during 338 h of observations at two estuaries. During the prehatch and chick-rearing phases of breeding, which coincided with migration of salmonids from fresh to salt water, 74% of the detections of radio-tagged western gulls occurred within 25 km of Año Nuevo Island, suggesting that the relative susceptibility of predation by western gulls using Año Nuevo Island decreased with distance from the island. Western gull presence at creek mouths was greatest during daylight hours (91% of detections), while juvenile salmonids were present predominantly at night (65% of detections). The greatest overlap between western gulls and salmonids occurred at dusk, and predation of out-migrating salmonids was likely opportunistic. Deterring gulls from creek mouths when overlap between predator and prey might otherwise occur may buffer out-migrating salmonids from predation. Our results will inform management strategies to most effectively reduce the impacts of gull predation on central California salmonids.

Received May 8, 2014; accepted March 11, 2015
Nonchemical Eradication of an Introduced Trout from a Headwater Complex in Banff National Park, Canada
Authors: Pacas Charlie , Taylor Mark K.
Published: July 2015

Nonnative salmonids have been intentionally introduced in North America for over a century and are now implicated in the decline of native aquatic species. Current management objectives for some national parks are to remove invasive species, where feasible. We evaluated the use of mechanical methods (gill nets and electrofishing) to eliminate a naturalized population of nonnative Brook Trout Salvelinus fontinalis in a subalpine headwater basin. We required a total of 1,383 continuous net nights/ha (net nights = number of nets × number of nights) over 5 years to completely eradicate 1,527 Brook Trout from both Lower (9.7 ha; 6 m maximum depth) and Middle (23.1 ha; 25 m maximum depth) Devon Lakes, Alberta, Canada. Electrofishing along the shoreline of both lakes resulted in the capture of 301 Brook Trout over 4 years. We required a total of 52.1 h/km of electrofishing over 5 years to completely remove 3,288 Brook Trout from the upper 4.5 km of the Clearwater River. We verified the absence of fish in the lakes with 1,558 net nights/ha of sampling over 4 years and in the river with 13.6 h/km over 2 years. This project confirms that mechanical methods are a viable option for removing introduced fish, even in relatively large (up to 20 ha) and deep (up to 25 m) mountain lakes. We surmised that our success (relative to that of projects described in the literature) was due to (1) the relatively simple alpine habitat, in which river and lake margins were clear of macrophytes, suspended sediment, and overhanging riparian vegetation, and (2) the sheer magnitude of our effort.
Muskellunge Growth Potential in Northern Wisconsin: Implications for Trophy Management
Authors: Faust Matthew D. , Isermann Daniel A. , Luehring Mark A. , Hansen Michael J.
Published: July 2015

The growth potential of Muskellunge Esox masquinongy was evaluated by back-calculating growth histories from cleithra removed from 305 fish collected during 1995–2011 to determine whether it was consistent with trophy management goals in northern Wisconsin. Female Muskellunge had a larger mean asymptotic length (49.8 in) than did males (43.4 in). Minimum ultimate size of female Muskellunge (45.0 in) equaled the 45.0-in minimum length limit, but was less than the 50.0-in minimum length limit used on Wisconsin's trophy waters, while the minimum ultimate size of male Muskellunge (34.0 in) was less than the statewide minimum length limit. Minimum reproductive sizes for both sexes were less than Wisconsin's trophy minimum length limits. Mean growth potential of female Muskellunge in northern Wisconsin appears to be sufficient for meeting trophy management objectives and angler expectations. Muskellunge in northern Wisconsin had similar growth potential to those in Ontario populations, but lower growth potential than Minnesota's populations, perhaps because of genetic and environmental differences.
Biosynthesis of coenzyme Q in eukaryotes
Authors: Kawamukai Makoto
Published: July 2015

Coenzyme Q (CoQ) is a component of the electron transport chain that participates in aerobic cellular respiration to produce ATP. In addition, CoQ acts as an electron acceptor in several enzymatic reactions involving oxidation–reduction. Biosynthesis of CoQ has been investigated mainly in Escherichia coli and Saccharomyces cerevisiae, and the findings have been extended to various higher organisms, including plants and humans. Analyses in yeast have contributed greatly to current understanding of human diseases related to CoQ biosynthesis. To date, human genetic disorders related to mutations in eight COQ biosynthetic genes have been reported. In addition, the crystal structures of a number of proteins involved in CoQ synthesis have been solved, including those of IspB, UbiA, UbiD, UbiX, UbiI, Alr8543 (Coq4 homolog), Coq5, ADCK3, and COQ9. Over the last decade, knowledge of CoQ biosynthesis has accumulated, and striking advances in related human genetic disorders and the crystal structure of proteins required for CoQ synthesis have been made. This review focuses on the biosynthesis of CoQ in eukaryotes, with some comparisons to the process in prokaryotes.
Judging the implications of a concession: Conversational distance and belief bias effects
Authors: Ricco Robert B. , Sierra Anthony
Published: July 2015

An arguer's position at a given point in an argument can be characterized as a set of commitments. The present study considers the perceptions of ordinary language users about the implications of making a concession for the contents of the conceder's commitment set. In particular, we examine two sources of influence on such lay perceptions— conversational distance (i.e., the number of turns separating the concession from commitments incurred earlier in the argument) and an individual's prior beliefs regarding the content of the argument. Across two studies, college students were administered an argument task assessing the extent to which a concession by the protagonist of an argument on the last move indicated changes to other commitments incurred earlier in the argument. Results indicated that participants were more likely to judge a concession as indicating a change in prior commitments if (a) the commitment was incurred later in the argument than earlier, and (b) the participant disagreed with the protagonists’ thesis in the argument. In addition, performance on deductive reasoning tasks predicted individual differences in the conversational distance effect, but not the belief bias effect.
Estimating the Dependence of Spawning Frequency on Size and Age in Gulf of Mexico Red Snapper
Authors: Porch C. E. , Fitzhugh G. R. , Lang E. T. , Lyon H. M. , Linton B. C.
Published: July 2015

In 2011, a large multivessel survey was conducted to provide nearly synoptic sampling of Red Snapper Lutjanus campechanus throughout their reproductive season in the U.S. Gulf of Mexico. A total of 2,487 Red Snapper were caught with a female : male ratio that was approximately 1:1. The ovaries of 1,002 females were histologically examined. Females (n = 391) were found with spawning markers (postovulatory follicles and hydrated oocytes) throughout the study area, but primarily in outer shelf waters. Statistical models were developed to quantify and test the dependence of the proportion of females bearing spawning markers (spawning fraction) on female length and age, time of year, depth, gear type (vertical line or longline), or region (east or west of the Mississippi River). Most of the variance in spawning fraction was explained by the time of year; spawning fractions were generally low in spring, peaked in midsummer, and declined by fall. There was also strong statistical evidence of a positive relationship between spawning fraction and either age or length. The effects of region and gear type were not significant once time of year and size or age were accounted for. These results demonstrate the need to account for differences in the time of year and age structure of the population when the productivity of populations of Red Snapper are compared. For example, productivity has been hypothesized to be greater in the western Gulf than in the eastern Gulf, as evidenced by regional patterns of egg and larval abundance. Our results suggest that this regional difference is not due to any intrinsic difference in the biology of the fish, but simply a consequence of there being more large, old Red Snapper in the western Gulf. Recent stock assessments have indicated that Red Snapper are increasing in abundance and there is a need to continue monitoring to detect any possible compensation in reproduction.

Received November 25, 2014; accepted April 2, 2015
Nonlinear Young integrals and differential systems in Hölder media
Authors: Hu Yaozhong , Lê Khoa
Published: July 2015

For Hölder continuous random field

W
(
t
,
x
)

W(t,x)

and stochastic process

φ
t

\varphi _t

, we define nonlinear integral

∫
a
b

W
(
d
t
,

φ
t

)

\int _a^b W(dt, \varphi _t)

in various senses, including pathwise and Itô-Skorohod. We study their properties and relations. The stochastic flow in a time dependent rough vector field associated with

φ
˙

t

=
(

∂
t

W
)
(
t
,

φ
t

)

\dot \varphi _t=(\partial _tW)(t, \varphi _t)

is also studied, and its applications to the transport equation
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="partial-differential Subscript t Baseline u left-parenthesis t comma x right-parenthesis minus partial-differential Subscript t Baseline upper W left-parenthesis t comma x right-parenthesis nabla u left-parenthesis t comma x right-parenthesis equals 0">

∂
t

u
(
t
,
x
)
−

∂
t

W
(
t
,
x
)
∇
u
(
t
,
x
)
=
0

\partial _t u(t,x)-\partial _t W(t,x)\nabla u(t,x)=0

in rough media are given. The Feynman-Kac solution to the stochastic partial differential equation with random coefficients
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="partial-differential Subscript t Baseline u left-parenthesis t comma x right-parenthesis plus upper L u left-parenthesis t comma x right-parenthesis plus u left-parenthesis t comma x right-parenthesis partial-differential Subscript t Baseline upper W left-parenthesis t comma x right-parenthesis equals 0">

∂
t

u
(
t
,
x
)
+
L
u
(
t
,
x
)
+
u
(
t
,
x
)

∂
t

W
(
t
,
x
)
=
0

\partial _t u(t,x)+Lu(t,x) +u(t,x) \partial _t W(t,x)=0

is given, where

L
L

is a second order elliptic differential operator with random coefficients (dependent on

W
W

). To establish such a formula the main difficulty is the exponential integrability of some nonlinear integrals, which is proved to be true under some mild conditions on the covariance of

W
W

and on the coefficients of

L
L

. Along the way, we also obtain an upper bound for increments of stochastic processes on multi- dimensional rectangles by majorizing measures.
On parametrizing exceptional tangent cones to Prym theta divisors
Authors: Smith Roy , Varley Robert
Published: July 2015

The theta divisor of a Jacobian variety is parametrized by a smooth divisor variety via the Abel map, with smooth projective linear fibers. Hence the tangent cone to a Jacobian theta divisor at any singularity is parametrized by an irreducible projective linear family of linear spaces normal to the corresponding fiber. The divisor variety

X
X

parametrizing a Prym theta divisor

Ξ
\Xi

, on the other hand, is singular over any exceptional point. Hence although the fibers of the Abel Prym map are still smooth, the normal cone in

X
X

parametrizing the tangent cone of

Ξ
\Xi

can have nonlinear fibers.

In this paper we highlight the diverse and interesting structure that these parametrizing maps can have for exceptional tangent cones to Prym theta divisors. We also propose an organizing framework for the various possible cases. As an illustrative example, we compute the case of a Prym variety isomorphic to the intermediate Jacobian of a cubic threefold, where the projectivized tangent cone, the threefold itself, is parametrized by the 2 parameter family of cubic surfaces cut by hyperplanes through a fixed line on the threefold.
No more detectable fishing effect on Northern Gulf of St Lawrence benthic invertebrates
Authors: Moritz C. , Gravel D. , Savard L. , McKindsey C. W. , Brêthes J.-C. , Archambault P.
Published: July 2015

Trawling has been reported worldwide to alter seabed structure, and thus benthic habitats and ecosystems. Usually, a decrease in species richness and biomass is observed, and community structure is modified towards more opportunistic species. The Gulf of St Lawrence (Canada) has been intensely exploited since the 17th century, including net, longline, dredge and trawl fishing activities. Recently, the collapse of groundfish stocks induced a shift in fishing practices toward shrimp trawling, which is currently considered a sustainable fishing activity in the region. However, no long-term study has evaluated the potential effects of trawling disturbances on benthic mega-invertebrates. We investigated whether shrimp trawling had long- (ca. 20 years), mid- (ca. 10 years), and short-term (ca. 4 years) impacts on benthic mega-invertebrate taxa richness, biomass, and community structure. Scientific and fishery trawling data analyses showed that no significant long-, mid-, or short-term effect was detected on taxa richness. Significant but weak effects on biomass and community structure were detected at the mesoscale, i.e. at the scale of fishing grounds. In this long-exploited ecosystem, we suggest that a critical level of disturbance was attained by the first gear passages, which occurred decades ago and had irreversible impacts on the seabed by removing vulnerable taxa and structures that provided three-dimensional habitats. It is likely that benthic communities have subsequently reached a disturbed state of equilibrium on which current trawling disturbance has limited or no further impacts.
Do Pharmacists Buy Bayer? Informed Shoppers and the Brand Premium *
Authors: Bronnenberg Bart J. , Dubé Jean-Pierre , Gentzkow Matthew , Shapiro Jesse M.
Published: July 2015

We estimate the effect of information and expertise on consumers’ willingness to pay for national brands in physically homogeneous product categories. In a detailed case study of headache remedies, we find that more informed or expert consumers are less likely to pay extra to buy national brands, with pharmacists choosing them over store brands only 9 percent of the time, compared to 26 percent of the time for the average consumer. In a similar case study of pantry staples such as salt and sugar, we show that chefs devote 12 percentage points less of their purchases to national brands than demographically similar nonchefs. We extend our analysis to cover 50 retail health categories and 241 food and drink categories. The results suggest that misinformation and related consumer mistakes explain a sizable share of the brand premium for health products, and a much smaller share for most food and drink products. We tie our estimates together using a stylized model of demand and pricing.
Her-2 Expression in Gastroesophageal Intestinal Metaplasia, Dysplasia, and Adenocarcinoma
Authors: Almhanna Khaldoun , Rosa Marilin , Henderson-Jackson Evita , Jiang Kun , Shamekh Rania , Sayegh Zena , Malafa Mokenge P. , Coppola Domenico
Published: July 2015

Overexpression of human epidermal growth factor receptor 2 protein (Her-2) in Barrett neoplasia is significant for targeted therapy with trastuzumab. Here, we studied the frequency of Her-2 overexpression in Barrett adenocarcinoma and precursor lesions. Retrospective formalin-fixed paraffin-embedded tissue samples of 25 normal (NM) esophageal mucosa, 50 Barrett esophagus (BE) without dysplasia, 49 BE with low-grade dysplasia (LGD), 50 BE with high-grade dysplasia (HGD), and 50 invasive adenocarcinoma (ICA) were used. A BE tissue microarray was built and analyzed by Her-2 immunohistochemistry (IHC) and Her-2 dual in situ hybridization (DISH). Her-2 IHC expression was negative in NM and low in 26% of BE (IHC score: 1+) and in 24.5% of LGD (IHC score: 1 to 2+). Her-2 overexpression was seen in 28% of HGD and in 24% of ICA (IHC score: 2 to 3+). Her-2 DISH was negative in NM and BE but positive in 6% of LGD, 20% of HGD, and 18% of ICA. Differences in Her-2 DISH positivity between NM and HGD or ICA were statistically significant (P=0.02), but those between NM and LGD or HGD and ICA were not (P=0.2). Although Her-2 overexpression results in ICA were similar to previous reports, the finding of 28% in HGD was unexpected and may have clinical implications. Positive Her-2 DISH in 6% of LGD is novel, suggesting a role of Her-2 during BE progression.
A Dual Color Immunohistochemistry Assay for Measurement of Cereblon in Multiple Myeloma Patient Samples
Authors: Ren Yan , Wang Maria , Couto Suzana , Hansel Donna E. , Miller Karen , Lopez-Girona Antonia , Bjorklund Chad C. , Gandhi Anita K. , Thakurta Anjan , Chopra Rajesh , Breider Michael
Published: July 2015

Clinical interest in the measurement of Cereblon (CRBN), the primary target of the IMiDs immunomodulatory drugs lenalidomide and pomalidomide, has been fueled by its essential requirement for antitumor or immunomodulatory activity of both drugs in multiple myeloma (MM). However, limited analyses of clinical samples for CRBN gene expression or protein levels have utilized unvalidated reagents and assays, raising uncertainty about the interpretation of these results. We previously described a highly specific rabbit monoclonal antibody CRBN65 against 65-76 AA of human Cereblon. Here we describe a validated dual color bright-field Cereblon/CD138 immunohistochemical (IHC) assay utilizing CRBN65 and a commercial mouse monoclonal CD138 antibody. Sensitivity and specificity of the assay was determined and assay precision was shown for both cytoplasmic and nuclear Cereblon in MM bone marrow samples with coefficient of variation values of 5% and 2%, respectively. The dual IHC assay was effective for detecting a continuous range of Cereblon levels in 22 MM patient bone marrow core biopsies and aspirate clots, as shown by average cytoplasmic H-scores ranging from 63 to 267 and nuclear H-scores ranging from 17 to 250. Interpathologist comparison of MM sample H-scores by 3 pathologists demonstrated good concordance (R
2=0.73). This dual assay demonstrated superior Cereblon IHC measurement in MM samples compared with the single IHC assay using a published commercial rabbit polyclonal Cereblon antibody and could be used to explore the potential utility of Cereblon as a biomarker in the clinic.
Terasakiispira papahanaumokuakeensis gen. nov., sp. nov., a gammaproteobacterium from Pearl and Hermes Atoll, Northwestern Hawaiian Islands
Authors: Zepeda Vanessa K. , Busse Hans-Jürgen , Golke Jan , Saw Jimmy H. W. , Alam Maqsudul , Donachie Stuart P.
Published: July 2015

A Gram-negative, helical bacterium designated PH27AT was cultivated from an anchialine pool on Pearl and Hermes Atoll, Northwestern Hawaiian Islands. The obligately halophilic strain was motile by bipolar tufts of flagella and grew optimally at pH 7, and microaerobically or aerobically. Closest neighbours based on 16S rRNA gene nucleotide sequence identity are Marinospirillum celere v1c_Sn-redT (93.31 %) and M. alkaliphilum Z4T (92.10 %) in the family Oceanospirillaceae, class Gammaproteobacteria. PH27AT is distinguished phenotypically from members of the genus Marinospirillum by its hydrolysis of gelatin, the absence of growth in media containing ≤ 1 % (w/v) NaCl and the ranges of temperature (12–40 °C) and pH (5–8) for growth. The major compound ubiquinone Q-9 distinguishes the quinone system of strain PH27AT from those in members of the genus Marinospirillum and other members of the Oceanospirillaceae, in which the major quinone is Q-8. Major polar lipids in PH27AT were phosphatidylethanolamine and phosphatidylglycerol, with moderate amounts of diphosphatidylglycerol and phosphatidylserine. Spermidine and cadaverine dominated the polyamine pattern; large proportions of cadaverine have not been reported in members of the genus Marinospirillum. Genotypic and chemotaxonomic data show that PH27AT does not belong in the genus Marinospirillum or other genera of the family Oceanospirillaceae or the Halomonadaceae. We propose a new genus, Terasakiispira gen. nov., be created to accommodate Terasakiispira papahanaumokuakeensis gen. nov., sp. nov. as the type species, with PH27AT ( = ATCC BAA-995T = DSM 16455T = DSM 23961T) as the type strain.
Pedobacter nanyangensis sp. nov., isolated from herbicide-contaminated soil
Authors: Zhang Hao , Zhang Jing , Song Man , Cheng Ming-gen , Wu Ya-dong , Guo Su-hui , Li Qiang , Hong Qing , Huang Xing
Published: July 2015

A Gram-stain-negative, strictly aerobic, non-spore-forming, motile, rod-shaped bacterium, designated Q-4T, was isolated from a herbicide-contaminated soil sample in Nanyang, Henan province, China. Strain Q-4T grew optimally in the LB medium without NaCl supplement at a pH range of 6.0–7.0 and a temperature of 30 °C. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Q-4T was most closely related to ‘Pedobacter zeaxanthinifaciens’ TDMA-5 (97.4 % 16S rRNA gene sequence similarity), followed by Pedobacter xixiisoli S27T (95.8 %). The genomic DNA G+C content of strain Q-4T was 41.8 mol%. MK-7 was the major respiratory quinone. Phosphatidylethanolamine and phosphoaminolipid were the major polar lipids. The major fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH, C16 : 1ω6c and/or C16 : 1ω7c (summed feature 3) and C16 : 1ω7c/C16 : 1ω6c (summed feature 3). Strain Q-4T showed low DNA–DNA relatedness with ‘P. zeaxanthinifaciens’ TDMA-5 (21.4 ± 0.6 %). Physiological and biochemical characteristics are able to distinguish strain Q-4T from the most closely related species of the genus Pedobacter. On the basis of genotypic and phenotypic data, strain Q-4T is considered to represent a novel species of the genus Pedobacter, for which the name Pedobacter nanyangensis sp. nov. is proposed. The type strain is Q-4T ( = KCTC 42442T = ACCC 19798T).
Hanseniaspora jakobsenii sp. nov., a yeast isolated from Bandji, a traditional palm wine of Borassus akeassii
Authors: Ouoba Labia Irène I. , Nielsen Dennis S. , Anyogu Amarachukwu , Kando Christine , Diawara Bréhima , Jespersen Lene , Sutherland Jane P.
Published: July 2015

Investigation of the microbial diversity of Bandji, a traditional palm wine from Burkina Faso (West Africa) revealed the presence of two yeast isolates (YAV16 and YAV17T) with unusual phenotypic and genotypic characteristics. The isolates divide by bipolar budding with no production of ascospores. Phylogenetic analysis of concatenated sequences of the 26S rRNA gene D1/D2 and internal transcribed spacer (ITS) regions indicated that the novel species was most closely related to Kloeckera lindneri and Hanseniaspora valbyensis. The new isolates differed from K. lindneri NRRL Y-17531T and H. valbyensis CBS 479T by substitutions in the D1/D2 region of 12 and 16 nt respectively. The divergence in the ITS region from the closely related species was characterized by substitutions of 45–46 nt. Repetitive palindromic PCR (rep-PCR) profiles of YAV16 and YAV17T were also significantly different from those of K. lindneri MUCL 31146T ( = NRRL Y-17531T), H. valbyensis NCYC 17T ( = CBS 479T) and other species of the genus Hanseniaspora. Based on the results of the phenotypic and genotypic characterizations, it was concluded that the new isolates represent a novel species for which the name Hanseniaspora jakobsenii sp. nov. is proposed with YAV17T ( = CBS 12942T = DSM 26339T = NCYC 3828T; MycoBank number MB 805785) as the type strain.
The Macromolecular Neutron Diffractometer MaNDi at the Spallation Neutron Source
Authors: Coates Leighton , Cuneo Matthew J. , Frost Matthew J. , He Junhong , Weiss Kevin L. , Tomanicek Stephen J. , McFeeters Hana , Vandavasi Venu Gopal , Langan Paul , Iverson Erik B.
Published: July 2015

The Macromolecular Neutron Diffractometer (MaNDi) is located on beamline 11B of the Spallation Neutron Source at Oak Ridge National Laboratory. The instrument is a neutron time-of-flight wavelength-resolved Laue diffractometer optimized to collect diffraction data from single crystals. The instrument has been designed to provide flexibility in several instrumental parameters, such as beam divergence and wavelength bandwidth, to allow data collection from a range of macromolecular systems.
An in situ neutron diffraction study of anomalous superelasticity in a strain glass Ni43Fe18Ga27Co12 alloy
Authors: Zhang Q. H. , Zhai Z. , Nie Z. H. , Harjo S. , Cong D. Y. , Wang M. G. , Li J. , Wang Y. D.
Published: July 2015

Superelastic behavior is traditionally related to the martensitic transition with a collective transformation scenario in some shape memory alloys. A kind of quasi-linear superelasticity accompanied by a finite avalanche or confined martensitic transformation was recently found in some alloy systems with strain glass state. Here, an in situ neutron diffraction technique was used to study the deformation behavior in an Ni43Fe18Ga27Co12 alloy with strain glass state in order to reveal the new intrinsic physical nature of the quasi-linear superelasticity. A significant modulus softening prior to the stress-induced martensitic transformation was observed during compression in the studied alloy, which is similar to the characteristics exhibited in the tweed precursor phenomena prior to temperature-induced martensitic transformation. Moreover, the diffraction peak broadening was further shown during the elastic stage of deformation for both single-crystal and polycrystalline samples, which mainly stems from the short-range fluctuation in the strain field inside each grain based on Williamson–Hall analysis. The authors believe that there exists a spatial heterogeneity in the modulus of the confined martensitic transformation alloy.
Small-angle scattering of particle assemblies
Authors: Senesi Andrew J. , Lee Byeongdu
Published: July 2015

Small-angle scattering formulae for crystalline assemblies of arbitrary particles are derived from powder diffraction theory using the decoupling approximation. To do so, the pseudo-lattice factor is defined, and methods to overcome the limitations of the decoupling approximation are investigated. Further, approximated equations are suggested for the diffuse scattering from various defects of the first kind due to non-ideal particles, including size polydispersity, orientational disorder and positional fluctuation about their ideal positions. Calculated curves using the formalism developed herein are compared with numerical simulations computed without any approximation. For a finite-sized assembly, the scattering from the whole domain of the assembly must also be included, and this is derived using the correlation function approach.
OrientXplot: a program to analyse and display relative crystal orientations
Authors: Angel Ross , Milani Sula , Alvaro Matteo , Nestola Fabrizio
Published: July 2015

Orientations of single crystals are usually determined by diffraction experiments. Indexing of a diffraction pattern from one crystal leads to the determination of its `orientation matrix', which defines the orientation of its crystallographic axes relative to a set of reference axes associated with the diffractometer. Crystal orientations can also be described in terms of Euler angles, especially from electron backscattered diffraction measurements. OrientXplot is a Windows program that reads all common types of orientation matrices, as well as orientation data such as Euler angles. The program calculates and displays the relative orientations of pairs of crystals, such as twins or inclusion crystals trapped inside host crystals. OrientXplot can manipulate (under user control) the orientation matrices to allow for ambiguities in indexing that arise from crystal symmetries. Orientation data can be displayed on a stereogram or output in numerical form for plotting in external programs.
Implementing an employee career-development strategy
Authors: Davis Paul J
Published: July 2015

Purpose

– Demonstrates how to build commitment and retain employees through a career-development strategy.

Design/methodology/approach

– Shows how organizations often mismanage career development and how they could do better.

Findings

– Describes the five “Ps” of poor career development, the foundations of a career-development strategy and a number of career-development activities.

Practical implications

– Highlights the importance of beginning early, communicating clearly, partnering employees, facilitating internal movements and taking action frequently.

Social implications

– Advances the view that employee disengagement and high employee turnover are expensive and often avoidable.

Originality/value

– Argues that the lack of career development continues to be a major cause of employee dissatisfaction and turnover and shows how this can be avoided.