bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface plasmon resonance microscopy: Achieving a quantitative optical response
Authors: Peterson Alexander W. , Halter Michael , Plant Anne L. , Elliott John T.
Published: September 2016

Surface plasmon resonance (SPR) imaging allows real-time label-free imaging based on index of refraction and changes in index of refraction at an interface. Optical parameter analysis is achieved by application of the Fresnel model to SPR data typically taken by an instrument in a prism based figuration. We carry out SPR imaging on a microscope by launching light into a sample and collecting reflected light through a high numerical aperture microscope objective. The SPR microscope enables spatial resolution that approaches the diffraction limit and has a dynamic range that allows detection of subnanometer to submicrometer changes in thickness of biological material at a surface. However, unambiguous quantitative interpretation of SPR changes using the microscope system could not be achieved using the Fresnel model because of polarization dependent attenuation and optical aberration that occurs in the high numerical aperture objective. To overcome this problem, we demonstrate a model to correct for polarization diattenuation and optical aberrations in the SPR data and develop a procedure to calibrate reflectivity to index of refraction values. The calibration and correction strategy for quantitative analysis was validated by comparing the known indices of refraction of bulk materials with corrected SPR data interpreted with the Fresnel model. Subsequently, we applied our SPR microscopy method to evaluate the index of refraction for a series of polymer microspheres in aqueous media and validated the quality of the measurement with quantitative phase microscopy.
Devaney chaos plus shadowing implies distributional chaos
Authors: Li Jian , Li Jie , Tu Siming
Published: September 2016

We explore connections among the regional proximal relation, the asymptotic relation, and the distal relation for a topological dynamical system with the shadowing property and show that if a Devaney chaotic system has the shadowing property then it is distributionally chaotic.
Double differential cross sections for proton induced electron emission from molecular analogues of DNA constituents for energies in the Bragg peak region
Authors: Rudek Benedikt , Bennett Daniel , Bug Marion U. , Wang Mingjie , Baek Woon Yong , Buhr Ticia , Hilgers Gerhard , Champion Christophe , Rabus Hans
Published: September 2016

For track structure simulations in the Bragg peak region, measured electron emission cross sections of DNA constituents are required as input for developing parameterized model functions representing the scattering probabilities. In the present work, double differential cross sections were measured for the electron emission from vapor-phase pyrimidine, tetrahydrofuran, and trimethyl phosphate that are structural analogues to the base, the sugar, and the phosphate residue of the DNA, respectively. The range of proton energies was from 75 keV to 135 keV, the angles ranged from 15° to 135°, and the electron energies were measured from 10 eV to 200 eV. Single differential and total electron emission cross sections are derived by integration over angle and electron energy and compared to the semi-empirical Hansen-Kocbach-Stolterfoht (HKS) model and a quantum mechanical calculation employing the first Born approximation with corrected boundary conditions (CB1). The CB1 provides the best prediction of double and single differential cross section, while total cross sections can be fitted with semi-empirical models. The cross sections of the three samples are proportional to their total number of valence electrons.
Relaxation dynamics of multilayer triangular Husimi cacti
Authors: Galiceanu Mircea , Jurjiu Aurel
Published: September 2016

We focus on the relaxation dynamics of multilayer polymer structures having, as underlying topology, the Husimi cactus. The relaxation dynamics of the multilayer structures is investigated in the framework of generalized Gaussian structures model using both Rouse and Zimm approaches. In the Rouse type-approach, we determine analytically the complete eigenvalues spectrum and based on it we calculate the mechanical relaxation moduli (storage and loss modulus) and the average monomer displacement. First, we monitor these physical quantities for structures with a fixed generation number and we increase the number of layers, such that the linear topology will smoothly come into play. Second, we keep constant the size of the structures, varying simultaneously two parameters: the generation number of the main layer, G, and the number of layers, c. This fact allows us to study in detail the crossover from a pure Husimi cactus behavior to a predominately linear chain behavior. The most interesting situation is found when the two limiting topologies cancel each other. For this case, we encounter in the intermediate frequency/time domain regions of constant slope for different values of the parameter set (G, c) and we show that the number of layers follows an exponential-law of G. In the Zimm-type approach, which includes the hydrodynamic interactions, the quantities that describe the mechanical relaxation dynamics do not show scaling behavior as in the Rouse model, except the limiting case, namely, a very high number of layers and low generation number.
Acoustic one-way mode conversion and transmission by sonic crystal waveguides
Authors: Ouyang Shiliang , He Hailong , He Zhaojian , Deng Ke , Zhao Heping
Published: September 2016

We proposed a scheme to achieve one-way acoustic propagation and even–odd mode switching in two mutually perpendicular sonic crystal waveguides connected by a resonant cavity. The even mode in the entrance waveguide is able to switch to the odd mode in the exit waveguide through a symmetry match between the cavity resonant modes and the waveguide modes. Conversely, the odd mode in the exit waveguide is unable to be converted into the even mode in the entrance waveguide as incident waves and eigenmodes are mismatched in their symmetries at the waveguide exit. This one-way mechanism can be applied to design an acoustic diode for acoustic integration devices and can be used as a convertor of the acoustic waveguide modes.
Designs of blue and green light-emitting diodes based on type-II InGaN-ZnGeN2 quantum wells
Authors: Han Lu , Kash Kathleen , Zhao Hongping
Published: September 2016

Type-II InGaN-ZnGeN2 quantum wells (QWs) are studied as improved active regions for light-emitting diodes emitting in the blue (λ ∼ 485 nm) and green (λ ∼ 530 nm) spectral ranges. Both the energy band gap and the lattice parameters of ZnGeN2 are very close to those of GaN. The recently predicted large band offset between GaN and ZnGeN2 allows the formation of a type-II InGaN-ZnGeN2 heterostructure. The strong confinement of holes in the ZnGeN2 layer allows the use of a lower In-content InGaN QW to extend the emission wavelength into the blue and green wavelength regions, as compared to the traditional InGaN QW with uniform In content. In the type-II InGaN-ZnGeN2 QW designs, a thin AlGaN layer was used as a barrier for better carrier confinement. The type-II InGaN-ZnGeN2 QWs lead to a significant enhancement of the electron-hole wave function overlap as compared to those of the conventional QWs. Simulation studies of the proposed type-II QWs promise a significant enhancement of the spontaneous emission rate by 6.1–7.2 times for the QW design emitting at the blue wavelength region and 4.6–4.9 times for the QW design emitting at the green wavelength region, as compared to the conventional InGaN QWs emitting at the same wavelengths.
Optical properties and band bending of InGaAs/GaAsBi/InGaAs type-II quantum well grown by gas source molecular beam epitaxy
Authors: Pan Wenwu , Zhang Liyao , Zhu Liang , Li Yaoyao , Chen Xiren , Wu Xiaoyan , Zhang Fan , Shao Jun , Wang Shumin
Published: September 2016

Photoluminescence (PL) properties of In0.2Ga0.8As/GaAs0.96Bi0.04/In0.2Ga0.8As quantum well (QW) grown on GaAs substrates by gas source molecular beam epitaxy were studied by varying excitation power and temperature, respectively. The type-II transition energy shifts from 1.149 eV to 1.192 eV when increasing the excitation power from 10 mW to 150 mW at 4.5 K, which was ascribed to the band-bending effect. On the other hand, the type-II PL quenches quickly along with fast redshift with the increasing temperature due to the relaxation of the band bending caused by the thermal excitation process. An 8 band k·p model was used to analyze the electronic properties and the band-bending effect in the type-II QW. The calculated subband levels and transition energy fit well with the experiment results, and two thermal activation energies of 8.7 meV and 50 meV, respectively, are deduced.
Explanation of the barrier heights of graphene Schottky contacts by the MIGS-and-electronegativity concept
Authors: Mönch Winfried
Published: September 2016

Graphene-semiconductor contacts exhibit rectifying properties and, in this respect, they behave in exactly the same way as a “conventional” metal-semiconductor or Schottky contacts. It will be demonstrated that, as often assumed, the Schottky-Mott rule does not describe the reported barrier heights of graphene-semiconductor contacts. With “conventional” Schottky contacts, the same conclusion was reached already in 1940. The physical reason is that the Schottky-Mott rule considers no interaction between the metal and the semiconductor. The barrier heights of “conventional” Schottky contacts were explained by the continuum of metal-induced gap states (MIGSs), where the differences of the metal and semiconductor electronegativities describe the size and the sign of the intrinsic electric-dipoles at the interfaces. It is demonstrated that the MIGS-and-electronegativity concept unambiguously also explains the experimentally observed barrier heights of graphene Schottky contacts. This conclusion includes also the barrier heights reported for MoS2 Schottky contacts with “conventional” metals as well as with graphene.
Facet analysis of truncated pyramid semi-polar GaN grown on Si(100) with rare-earth oxide interlayer
Authors: Grinys Tomas , Dargis Rytis , Frentrup Martin , Jucevičienė Agnė Kalpakovaitė , Badokas Kazimieras , Stanionytė Sandra , Clark Andrew , Malinauskas Tadas
Published: September 2016

After epitaxial growth of GaN on Si(100) substrates using an Er2O3 interlayer, two dominant growth orientations can be observed: semi-polar (101¯3) as well as non-polar (112¯0). Epilayers with the (101¯3) orientation lead to the formation of truncated pyramids, which were studied in detail by high-resolution X-ray diffraction, photoluminescence, and scanning electron microscopy (SEM). Depending on the GaN growth orientation and in-plane relation to the Er2O3 interlayer, lattice mismatches in the growth plane were calculated. In order to understand the formation of truncated pyramids, a method for facet identification from SEM images under different tilt angles was developed. This method was used to reconstruct truncated pyramids from our experiments. These were then compared with calculations of the corresponding kinetic Wulff construction, to explain the preferential growth of (101¯3) GaN.
Average activity of excitatory and inhibitory neural populations
Authors: Roulet Javier , Mindlin Gabriel B.
Published: September 2016

We develop an extension of the Ott-Antonsen method [E. Ott and T. M. Antonsen, Chaos 18(3), 037113 (2008)] that allows obtaining the mean activity (spiking rate) of a population of excitable units. By means of the Ott-Antonsen method, equations for the dynamics of the order parameters of coupled excitatory and inhibitory populations of excitable units are obtained, and their mean activities are computed. Two different excitable systems are studied: Adler units and theta neurons. The resulting bifurcation diagrams are compared with those obtained from studying the phenomenological Wilson-Cowan model in some regions of the parameter space. Compatible behaviors, as well as higher dimensional chaotic solutions, are observed. We study numerical simulations to further validate the equations.
Investigating phase separation and structural coloration of self-assembled ternary polymer thin films
Authors: Vohra Varun , Galeotti Francesco , Giovanella Umberto , Anzai Takuya , Kozma Erika , Botta Chiara
Published: September 2016

Poly(3-hexylthiophene-2,5-diyl) (P3HT) can generate nanoporous structures with variable pore diameters ranging from 150 to 600 nm from spin-coated blends with polystyrene (PS). In the present study, we observe the effect of the addition of polymethylmethacrylate (PMMA) to P3HT:PS blends to increase the pore-to-pore dimensions up to the micrometer scale. The phase separation in the ternary blend can be directly visualized by replacing the commercial (non-emissive) PS with a boron-dipyrromethene functionalized PS to distinctively locate the red-emitting P3HT and the green-emitting PS phases. In particular, in the ternary blend with high PMMA contents, we observe that PS acts as a compatibilizing agent at the interface between the P3HT and PMMA phases. After selective removal of the PS and PMMA phases using acetone, we demonstrate that, in these P3HT structured thin films, iridescence can be observed as they exhibit angle dependent reflectivity which is further emphasized when covered with a thin metal layer. The metal covered nanostructured P3HT films display bright color switching properties with blue and red emission at low and high reflection angles, respectively.
Single layer graphene band hybridization with silver nanoplates: Interplay between doping and plasmonic enhancement
Authors: Syed Salmaan R. , Lim Guh-Hwan , Flanders Stuart J. , Taylor Adam B. , Lim Byungkwon , Chon James W. M.
Published: September 2016

In this paper, we report single layer graphene (SLG) hybridized with silver nanoplates, in which nanoplates act as either a charge doping or a field enhancement source for the SLG Raman spectrum. Surprisingly, the stiffening of both G and 2D peaks of more than 10 cm−1 was observed with no plasmonic enhancement of peaks, indicating that p-doping from nanoplates on SLG is occurring. Such observation is explained in terms of the contact separation distance between the graphene and the silver nanoplates being enough (∼4 Å) to cause a Fermi level shift in graphene to allow p-doping. When nanoplates were modified in shape with laser irradiation by either photothermal plasmon printing or laser induced ablation, the charge doping was lifted and the strong plasmonic enhancement of Raman signals was observed, indicating that the separation distance is increased. Further, when the nanoplates are oxidized, the two effects on the Raman bands of SLG are turned off, returning the Raman signals back to the original SLG state.
Note: Localization based on estimated source energy homogeneity
Authors: Turkaya Semih , Toussaint Renaud , Eriksen Fredrik Kvalheim , Lengliné Olivier , Daniel Guillaume , Flekkøy Eirik G. , Måløy Knut Jørgen
Published: September 2016

Acoustic signal localization is a complex problem with a wide range of industrial and academic applications. Herein, we propose a localization method based on energy attenuation and inverted source amplitude comparison (termed estimated source energy homogeneity, or ESEH). This inversion is tested on both synthetic (numerical) data using a Lamb wave propagation model and experimental 2D plate data (recorded with 4 accelerometers sensitive up to 26 kHz). We compare the performance of this technique with classic source localization algorithms: arrival time localization, time reversal localization, and localization based on energy amplitude. Our technique is highly versatile and out-performs the conventional techniques in terms of error minimization and cost (both computational and financial).
Dynamic characteristics of 410 nm semipolar (202¯1¯) III-nitride laser diodes with a modulation bandwidth of over 5 GHz
Authors: Lee Changmin , Zhang Chong , Becerra Daniel L. , Lee Seunggeun , Forman Charles A. , Oh Sang Ho , Farrell Robert M. , Speck James S. , Nakamura Shuji , Bowers John E. , DenBaars Steven P.
Published: September 2016

The dynamic characteristics of III-nitride multi-quantum well laser diodes (LDs) emitting at 410 nm were investigated. LDs were grown on semipolar (202¯1¯) bulk GaN substrates and fabricated into devices with cavity lengths ranging from 900 nm to 1800 nm. A 3-dB bandwidth of 5 GHz and 5 Gbit/s direct modulation with on-off keying were demonstrated, which were limited by the bandwidth of the photodetector used for the measurements. The differential gain of the LDs was determined to be 2.5 ± 0.5 × 10−16 cm2 by comparing the slope efficiency for different cavity lengths. Analysis of the frequency response showed that the K-factor, the gain compression factor, and the intrinsic maximum bandwidth were 0.33 ns, 7.4 × 10−17 cm3, and 27 GHz, respectively.
Tunable electronic properties of GeSe/phosphorene heterostructure from first-principles study
Authors: Yu Weiyang , Zhu Zhili , Zhang Shengli , Cai Xiaolin , Wang Xiangfu , Niu Chun-Yao , Zhang Wei-Bing
Published: September 2016

Vertical integration of two-dimensional materials has recently emerged as an exciting method for the design of electronic and optoelectronic devices. In this letter, first principles calculations are employed to explore the structural and electronic properties of the GeSe/phosphorene van der Waals (vdW) p-n heterostructure. Our results suggest that this heterostructure has an intrinsic type-II band alignment and indirect band gap. Moreover, we also find that an intriguing indirect-direct and insulator-metal transition can be induced by strain. In addition, spontaneous electron-hole charge separation is expected to occur, implying that the GeSe/phosphorene heterostructure is a good candidate for applications in optoelectronics. These results provide a route for applications of the GeSe/phosphorene vdW heterostructure in future flexible electronics, optoelectronics, and semiconductor devices.
Electrical properties of Ge crystals and effective Schottky barrier height of NiGe/Ge junctions modified by P and chalcogen (S, Se, or Te) co-doping
Authors: Koike Masahiro , Kamimuta Yuuichi , Tezuka Tsutomu , Yamabe Kikuo
Published: September 2016

The electrical properties of Ge crystals and the effective Schottky barrier height (SBH) of NiGe/Ge diodes fabricated by P and/or chalcogen (S, Se, or Te) doping were investigated for Ge n-channel metal–oxide–semiconductor field-effect transistors with a NiGe/n+Ge junction. The electron concentration in Ge was increased more by co-doping with chalcogen and P than by doping with P alone. Moreover, SBH values were decreased in NiGe/nGe diodes and increased in NiGe/pGe diodes compared with undoped NiGe/Ge by both P doping and P and chalcogen co-doping. Co-doping with Te and P was most effective in modifying the SBH.
Topological analysis of spin-torque driven magnetic skyrmion formation
Authors: Liu Yan , Yan Huan , Jia Min , Du HaiFeng , Du An
Published: September 2016

We performed micromagnetic simulations to investigate the exact underlying topological mechanism of skyrmion generation by blowing magnetic chiral stripe domains with a spin current generated by the spin Hall effect. This analysis of the topological dynamics reveals that the generation of a magnetic skyrmion is typically mediated by the creation and annihilation of an antiskyrmion. The threshold current density needed to generate persistent skyrmions depends on the damping constant, perpendicular magnetic field, and size of the sample.
Calibration and validation of AquaCrop for pearl millet (Pennisetum glaucum)
Authors: Bello Z. A. , Walker S.
Published: September 2016

Pearl millet (Pennisetum glaucum (L.) R.Br.) is widely grown in some of the driest regions of the world, mainly drier tropics. Although it is easy to cultivate under semi-arid and arid regions, it still responds very favourably to slight improvements in growing conditions such as supplementary irrigation. Because this crop is mostly cultivated under water-limited conditions, there is a need to develop strategies to promote efficient water use, and this can be achieved through field experiments and or crop modelling. The AquaCrop model requires a minimum number of crop parameters, with the aim of balancing simplicity, accuracy, robustness and user-friendliness. In this study, we calibrate and validate the AquaCrop model for an underutilised crop, pearl millet under irrigation and rainfed conditions. Experiments were carried out in lysimeters with two varieties of pearl millet (GCI 17, improved variety; Monyaloti, local variety) during the 2010–11 season. Field trials were conducted during the 2008–09 and 2009–10 seasons. The field plot was under a line-source sprinkler with four replications. Lysimeter datasets and field data (2008–09) were used for parameterisation and calibration of the model, and validation was done with the 2009–10 dataset. The model was able to simulate canopy cover, biomass production, cumulative evapotranspiration and grain yield, but not soil-water content, for the two varieties of pearl millet under irrigation and rainfed conditions. The performance of the model in simulating soil-water content is moderate for this crop and needs to be improved.
Olivine anisotropy suggests Gutenberg discontinuity is not the base of the lithosphere
Authors: Hansen Lars N. , Qi Chao , Warren Jessica M.
Published: September 2016

Significance

Although plate tectonics has seen broad acceptance for Earth, the manner in which lithospheric plates are coupled to Earth’s deeper interior is still heavily debated. In particular, recent seismological observations suggest a sharp, flat base of the lithosphere, whereas thermal models suggest a gradational boundary that deepens with age. Based on laboratory experiments, we suggest that thermal models are most appropriate and that seismic studies are detecting features frozen into the lithosphere after melting at midocean ridges. Experiments on olivine aggregates demonstrate that the seismic characteristics of deforming upper mantle are dramatically different between melt-free and low-melt-fraction aggregates. A model of upper-mantle flow incorporating these results predicts seismological features in excellent agreement with observations beneath the Pacific Ocean basin.
Thermoneutral immersion exercise accelerates heart rate recovery: A potential novel training modality
Authors: Garzon Mauricio , Dupuy Olivier , Bosquet Laurent , Nigam Anil , Comtois Alain Steve , Juneau Martin , Gayda Mathieu
Published: September 2016

This study compared heart rate recovery (HRR) after incremental maximal exercise performed at the same external power output (Pext) on dry land ergocycle (DE) vs. immersible ergocycle (IE). Fifteen young healthy participants (30 ± 7 years, 13 men and 2 women) performed incremental maximal exercise tests on DE and on IE. The initial Pext on DE was 25 W and was increased by 25 W/min at a pedalling cadence between 60 and 80 rpm, while during IE immersion at chest level in thermoneutral water (30°C), the initial Pext deployment was at a cadence of 40 rpm which was increased by 10 rpm until 70 rpm and thereafter by 5 rpm until exhaustion. Gas exchange and heart rate (HR) were measured continuously during exercise and recovery for 5 min. Maximal HR (DE: 176 ± 15 vs. IE 169 ± 12 bpm) reached by the subjects in the two conditions did not differ (P > .05). Parasympathetic reactivation parameters (ΔHR from 10 to 300 s) were compared during the DE and IE HR recovery recordings. During the IE recovery, parasympathetic reactivation in the early phase was more predominant (HRR at Δ10–Δ60 s, P < .05), but similar in the late phase (HRR at Δ120–Δ300 s, P > .05) when compared to the DE condition. In conclusion, incremental maximal IE exercise at chest level immersion in thermoneutral water accelerates the early phase parasympathetic reactivation compared to DE in healthy young participants.
Modelling plasma response to RMP fields in ASDEX Upgrade with varying edge safety factor and triangularity
Authors: Li L. , Liu Y.Q. , Kirk A. , Wang N. , Liang Y. , Ryan D. , Suttrop W. , Dunne M. , Fischer R. , Fuchs J.C. , Kurzan B. , Piovesan P. , Willensdorfer M. , Zhong F.C.
Published: September 2016

Toroidal computations are performed using the MARS-F code (Liu et al 2000 Phys. Plasmas
7 3681), in order to understand correlations between the plasma response and the observed mitigation of the edge localized modes (ELM) using resonant magnetic perturbation fields in ASDEX Upgrade. In particular, systematic numerical scans of the edge safety factor reveal that the amplitude of the resonant poloidal harmonic of the response radial magnetic field near the plasma edge, as well as the plasma radial displacement near the X-point, can serve as good indicators for predicting the optimal toroidal phasing between the upper and lower rows of coils in ASDEX Upgrade. The optimal coil phasing scales roughly linearly with the edge safety factor

q

95

, for various choices of the toroidal mode number n  =  1–4 of the coil configuration. The optimal coil phasing is also predicted to vary with the upper triangularity of the plasma shape in ASDEX Upgrade. Furthermore, multiple resonance effects of the plasma response, with continuously varying

q

95

, are computationally observed and investigated.
Coercivity of weighted Kohn Laplacians: The case of model monomial weights in ℂ²
Authors: Dall’Ara Gian Maria
Published: September 2016

The weighted Kohn Laplacian

◻

φ

\Box _\varphi

is a natural second order elliptic operator associated to a weight

φ
:

C

n

→

R

\varphi :\mathbb {C}^n\rightarrow \mathbb {R}

and acting on

(
0
,
1
)

(0,1)

-forms, which plays a key role in several questions of complex analysis.

We consider here the case of model monomial weights in

C

2

\mathbb {C}^2

, i.e.,
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="phi left-parenthesis z comma w right-parenthesis colon equals sigma-summation Underscript left-parenthesis alpha comma beta right-parenthesis element-of normal upper Gamma Endscripts StartAbsoluteValue z Superscript alpha Baseline w Superscript beta Baseline EndAbsoluteValue squared comma">

φ
(
z
,
w
)
:=

∑

(
α
,
β
)
∈
Γ

|

z
α

w
β

|

2

,

\varphi (z,w):=\sum _{(\alpha ,\beta )\in \Gamma }|z^\alpha w^\beta |^2,

\]
where

Γ
⊆

N

2

\Gamma \subseteq \mathbb {N}^2

is finite. Our goal is to prove coercivity estimates of the form
\[

(
∗
)

◻

φ

≥

μ
2

,

(*)\hspace {10pc} \Box _\varphi \geq \mu ^2,\hspace {10pc}

\]
where

μ
:

C

n

→

R

\mu :\mathbb {C}^n\rightarrow \mathbb {R}

acts by pointwise multiplication on

(
0
,
1
)

(0,1)

-forms, and the inequality is in the sense of self-adjoint operators. We proved in 2015 how to derive from

(
∗
)

(*)

new pointwise bounds for the weighted Bergman kernel associated to

φ
\varphi

. Here we introduce a technique to establish

(
∗
)

(*)

with
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="mu left-parenthesis z comma w right-parenthesis equals c left-parenthesis 1 plus StartAbsoluteValue z EndAbsoluteValue Superscript a Baseline plus StartAbsoluteValue w EndAbsoluteValue Superscript b Baseline right-parenthesis left-parenthesis a comma b greater-than-or-equal-to 0 right-parenthesis comma">

μ
(
z
,
w
)
=
c
(
1
+

|

z

|

a

+

|

w

|

b

)

(
a
,
b
≥
0
)
,

\mu (z,w)=c(1+|z|^a+|w|^b) \qquad (a,b\geq 0),

\]
where

a
,
b
≥
0

a,b\geq 0

depend on (and are easily computable from)

Γ
\Gamma

. As a corollary we also prove that, for a wide class of model monomial weights, the spectrum of

◻

φ

\Box _\varphi

is discrete if and only if the weight is not decoupled, i.e.,

Γ
\Gamma

contains at least a point

(
α
,
β
)

(\alpha ,\beta )

with

α
≠
0
≠
β

\alpha \neq 0\neq \beta

.

Our methods comprise a new holomorphic uncertainty principle and linear optimization arguments.
Anderson-Stark units for 𝔽_{𝕢}[𝜃]
Authors: Anglès Bruno , Pellarin Federico , Tavares Ribeiro Floric
Published: September 2016

We investigate the arithmetic of special values of a new class of

L
L

-functions recently introduced by the second author. We prove that these special values are encoded in some particular polynomials which we call Anderson-Stark units. We then use these Anderson-Stark units to prove that

L
L

-functions can be expressed as sums of polylogarithms.
Cooperative cell invasion: matrix metalloproteinase–mediated incorporation between cells
Authors: Mitchell Camilla B. , O’Neill Geraldine M.
Published: September 2016

Progression to metastatic disease is a leading cause of cancer death. Tumors are a complex mixture of cell types, both genetically heterogeneous malignant cells and associated nonmalignant cells. Models mimicking this heterogeneous cell environment have revealed that invasive cell populations can induce dissemination by otherwise poorly/noninvasive tumor cells, known as cooperative invasion. Neuroblastoma tumors arise in children and are characterized by mixed cellular populations in vivo, consisting chiefly of neuronal (N)-type and substrate (S)-type cells. The S-type cells have all the hallmarks of invasive leader cell populations and have been coisolated with N-type cells from metastatic bone lesions, but to date their ability to induce cooperative invasion has not been investigated. Therefore, in the present study, we analyzed the invasive behavior of mixed N-type and S-type multicellular spheroids embedded in three-dimensional collagen gels. Our analyses show that S-type cells induce invasion of either single cells or small cell clusters of N-type cells. In contrast to other reports of cooperative invasion in which mixed cultures exhibit a follow-the-leader mechanism, we show coincident emergence of S- and N-type cells from mixed spheroids. Our data suggest mutual effects between the two cell types. Thus, whereas coculture with S-type cells induces N-type invasion, coculture with N-type cells slows S-type invasion. Using matrix metalloproteinase (MMP) inhibitors and cell incorporation assays, we demonstrate that MMP activity is required for S-type cells to insert into layers of N-type cells. Our study therefore highlights an important role for S-type neuroblastoma cells in the invasion process and reveals a new mechanism of cooperative invasion.
Retrolinkin recruits the WAVE1 protein complex to facilitate BDNF-induced TrkB endocytosis and dendrite outgrowth
Authors: Xu Chenchang , Fu Xiuping , Zhu Shaoxia , Liu Jia-Jia
Published: September 2016

Retrolinkin, a neuronal membrane protein, coordinates with endophilin A1 and mediates early endocytic trafficking and signal transduction of the ligand–receptor complex formed between brain-derived neurotrophic factor (BDNF) and its receptor, tropomyosin-related kinase B (TrkB), in dendrites of CNS neurons. Here we report that retrolinkin interacts with the CYFIP1/2 subunit of the WAVE1 complex, a member of the WASP/WAVE family of nucleation-promoting factors that binds and activates the Arp2/3 complex to promote branched actin polymerization. WAVE1, not N-WASP, is required for BDNF-induced TrkB endocytosis and dendrite outgrowth. Disruption of the interaction between retrolinkin and CYFIP1/2 impairs recruitment of WAVE1 to neuronal plasma membrane upon BDNF addition and blocks internalization of activated TrkB. We also show that WAVE1-mediated endocytosis of BDNF-activated TrkB is actin dependent and clathrin independent. These results not only reveal the mechanistic role of retrolinkin in BDNF–TrkB endocytosis, but also indicate that WASP/WAVE-dependent actin polymerization during endocytosis is regulated by cell type–specific and cargo-specific modulators.
T-lymphocyte passive deformation is controlled by unfolding of membrane surface reservoirs
Authors: Guillou Lionel , Babataheri Avin , Saitakis Michael , Bohineust Armelle , Dogniaux Stéphanie , Hivroz Claire , Barakat Abdul I. , Husson Julien
Published: September 2016

T-lymphocytes in the human body routinely undergo large deformations, both passively, when going through narrow capillaries, and actively, when transmigrating across endothelial cells or squeezing through tissue. We investigate physical factors that enable and limit such deformations and explore how passive and active deformations may differ. Employing micropipette aspiration to mimic squeezing through narrow capillaries, we find that T-lymphocytes maintain a constant volume while they increase their apparent membrane surface area upon aspiration. Human resting T-lymphocytes, T-lymphoblasts, and the leukemic Jurkat T-cells all exhibit membrane rupture above a critical membrane area expansion that is independent of either micropipette size or aspiration pressure. The unfolded membrane matches the excess membrane contained in microvilli and membrane folds, as determined using scanning electron microscopy. In contrast, during transendothelial migration, a form of active deformation, we find that the membrane surface exceeds by a factor of two the amount of membrane stored in microvilli and folds. These results suggest that internal membrane reservoirs need to be recruited, possibly through exocytosis, for large active deformations to occur.
Consequences of catch-and-release angling for black bream Spondyliosoma cantharus, during the parental care period: implications for management
Authors: Pinder Adrian C. , Velterop Randolph , Cooke Steven J. , Britton J. Robert
Published: September 2016

Black sea bream Spondyliosoma cantharus is highly valued for its sporting and eating qualities. Due to its inshore spawning aggregations and male nest guarding behaviors, it is considered vulnerable to over-exploitation via recreational angling. Accordingly, greater uptake of the practice of catch-and-release (C&R) may provide some potential to limit the effects of angling on populations. Thus, the consequences of C&R for 40 S. cantharus (mean length 306 ± 10 mm) were assessed. Fish were sampled following their capture from charter boats by recreational anglers with varying levels of skill and experience. Of these fish, 17% were deeply hooked (e.g. in esophagus) and considered at high risk of post-release mortality (PRM). Blood lactate levels ranged between 0.40 and 2.60 mmol l − 1 (mean ± SE: 1.25 ± 0.09) and were significantly and positively correlated with fight time. Reflex impairments were observed in 32% of the catch, also suggesting an elevated probability of PRM. Hook damage was the only significant predictor of reflex impairment. The dominance of males (89%) across the catches highlighted the potential for additional indirect impacts of angling via the predation of eggs by conspecifics in the vacated nests of captured males. These results are discussed within the context of post-release performance of individual S. cantharus, the potential for C&R to limit impact at the population level and a need to consider future regulation of the fishery to ensure sustainability of stocks.
Impact of an Integrated Hip Fracture Inpatient Program on Length of Stay and Costs
Authors: Soong Christine , Cram Peter , Chezar Ksenia , Tajammal Faiqa , Exconde Kathleen , Matelski John , Sinha Samir K. , Abrams Howard B. , Fan-Lun Christopher , Fabbruzzo-Cota Christina , Backstein David , Bell Chaim M.
Published: September 2016

Background:

Hip fractures are associated with significant morbidity and mortality. Co-management models pairing orthopaedic surgeons with hospitalists or geriatricians may be effective at improving processes of care and outcomes such as length of stay (LOS) and cost. We set out to determine the effect of an integrated hip fracture co-management model on LOS, cost, and process measures.

Methods:

We conducted a single-center pre–post study of 571 patients admitted to an academic medical center with hip fractures between January 2009 and December 2013. The group receiving an integrated medical-surgical co-management incorporating continuous improvement methodology was compared with a control population. Primary outcome was LOS. Secondary outcomes included cost per case, time to surgery, osteoporosis (OP) treatment, preoperative echocardiogram utilization, mortality, and readmission.

Results:

LOS decreased from 18.2 (1.1) to 11.9 (1.5) days, a reduction of 6.3 days (P < 0.001). Mean cost decreased by $4953 (P < 0.001) per case. Mean time to surgery decreased from 45.8 (66.8) to 29.7 (17.9) hours (P < 0.001). Initiation of OP treatment increased from 55.8% to 96.4% (P < 0.001). Preoperative echocardiogram use decreased from 15.8% to 9.1% (P < 0.05). There was a nonsignificant difference in mortality rate (5.0% vs. 2.1%, P = 0.06). Readmission rate remained unchanged (4.6% vs. 6.0%, P = 0.56).

Conclusions:

An integrated medical-surgical co-management model incorporating continuous improvement methodology was associated with reduced LOS, costs, time to surgery, and increased initiation of appropriate OP treatment.

Level of Evidence:

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Bring Your Own Device and Nurse Managers’ Decision Making
Authors: Martinez Karen , Borycki Elizabeth , Courtney Karen L.
Published: September 2016

The Bring Your Own Device phenomenon is important in the healthcare environment because this trend is changing the workplace in healthcare organizations, such as British Columbia. At present, there is little research that exists in Canada to provide a distinct understanding of the complexities and difficulties unique to this phenomenon within the nursing practice. This study focused on the experiences and perceptions of nurse managers regarding how they make decisions on the use of personal handheld devices in the workplace. Telephone interviews (N = 10) and qualitative descriptive analysis were used. Four major themes emerged: (1) management perspective, (2) opportunities, (3) disadvantages, and (4) solutions. Nurse managers and other executives in healthcare organizations and health information technology departments need to be aware of the practice and organizational implications of the Bring Your Own Device movement.
Clinical and Histologic Effects of Fractional Microneedling Radiofrequency Treatment on Rosacea
Authors: Park Seon Yong , Kwon Hyuck Hoon , Yoon Ji Young , Min Seonguk , Suh Dae Hun
Published: September 2016

BACKGROUND

Fractional microneedling radiofrequency (FMR) is an emerging treatment modality, but its effect on rosacea has not been studied yet.

OBJECTIVE

To investigate the potential impact of FMR treatment on clinical improvement and histologic changes in rosacea patients.

MATERIALS AND METHODS

A 12-week, prospective, randomized, split-face clinical trial was conducted. Two sessions of FMR were performed on one side of the cheeks with 4-week interval and the other side remained untreated. Erythema index from DermaSpectrometer and a* value from Spectrophotometer CM-2002 were measured at each visit for the objective measurement of erythema. Histologic analysis of skin samples was also carried out.

RESULTS

Clinical evaluation and photometric measurement revealed the reduction of redness in the treated side compared with untreated side and baseline. Erythema index decreased 13.6% and a* value decreased 6.8% at Week 12 compared with baseline. Reduced expression of markers related to inflammation, innate immunity, and angiogenesis was observed in immunohistochemical staining of tissue obtained after FMR treatment.

CONCLUSION

Fractional microneedling radiofrequency treatment showed modest clinical and histologic improvement of rosacea, and it might be used as an alternative or in combination with other treatment methods.
Effect of Atherosclerosis on the Lateral Circumflex Femoral Artery and Its Descending Branch: Comparative Study to Nonatherosclerotic Risk
Authors: Burusapat Chairat , Nanasilp Tirapat , Kunaphensaeng Paiboon , Ruamthanthong Anuchit
Published: September 2016

Background:

The anterolateral thigh (ALT) flap has been widely used for reconstructions. Nevertheless, the atherosclerotic risk factors that affect the lateral circumflex femoral artery (LCFA) are still inconclusive. The aim was to study the effect of atherosclerosis on the LCFA and descending branch (dLCFA) visualized by computer tomographic angiography (CTA) between nonatherosclerosis and atherosclerosis.

Methods:

Retrospective studies of CTA of lower extremity were reviewed. The patients were divided into 2 groups: nonatherosclerotic and atherosclerotic risk factors. The angiographic study of LCFA and dLCFA was analyzed, and atherosclerotic and nonatherosclerotic risk factors were compared.

Results:

Ninety-seven patients with 194 lower extremities were enrolled. Atherosclerotic risks comprised 76 patients. A total of 14, 16, and 46 patients had 1, 2, and 3 risk factors, respectively. Musculocutaneous perforator was 79.38%. The LCFA originated from deep femoral, common femoral, and superficial femoral artery was 97.42%, 2.06%, and 0.52%, respectively. The dLCFA was classified into 5 types depending on its origin. Diameters of LCFA in nonatherosclerotic and atherosclerotic patients were 4.03 ± 0.71 and 4.07 ± 0.97 mm, respectively. No statistical significance was found between both groups in diameters of LCFA. Diameters of dLCFA in nonatherosclerotic patients were 2.28 ± 0.28 mm and in atherosclerotic patients were 2.11 ± 0.28 mm. Statistical significance of diameters of dLCFA was found in patients having 3 risk factors and smoker groups (p < 0.05).

Conclusions:

LCFA is not atherosclerosis resistant. Stenosis of the LCFA and dLCFA occurred in varying degrees in atherosclerosis-risk patients. Preoperative CTA should be considered to evaluate the patency in multiple risk factors patients.
The Transareolar–Periareolar Approach
Authors: Zelken Jonathan , Huang Jung-Ju , Wu Chih-Wei , Lin Yi-Ling , Cheng Ming-Huei
Published: September 2016

The periareolar approach is limited by areolar diameter. Asian women typically have smaller areolae than Western women. Voluminous and form-stable silicone implants demand larger incisions. Zigzag transareolar approaches closely approximate the nipple and improve exposure, but scar appearance remains problematic, and there is a risk of ductal injury and capsular contracture. We prefer a zigzag incision that straddles the areolar border. Between 2013 and 2015, 11 augmentation mammoplasties (20 incisions) were performed through a transareolar–periareolar (TAPA) incision. The TAPA incision resembles 3 inverted V’s that traverse the inferior areolar border. Outcomes were evaluated on the basis of photographs, clinical charts, and surveys. Women were 36 years old (range, 25–50). Silicone implants were used in 10 patients and saline in 1 patient. Implants were 270 cm3, placed in subpectoral position in 6 patients and subglandular position in 5. Follow-up was 12.5 months (range, 5–20 mo); there were no hematomas or infections. There was 1 case each of seroma (9.1%) and unilateral capsular contracture (9.1%) after secondary mammoplasty. There was no implant malposition or contour deformity. There were no keloids or hypertrophic scars. Every patient was satisfied. Nipple sensation was maintained or heightened in 100% of patients surveyed. The incisions were 139% longer than 180-degree periareolar scars. TAPA scars were well tolerated in this series of Asian women. We did not observe malposition, infection, or sensory disturbances. Despite its peripheral position on the nipple–areola complex, there are not enough data to determine whether TAPA incisions reduce risks compared with traditional approaches.
Descemet Membrane Endothelial Keratoplasty for Epithelial Downgrowth After Clear Corneal Cataract Surgery
Authors: Kim Young Shin , Jin So-Young , Chung Jin Kwon
Published: September 2016

Objectives:

To describe the first case of Descemet membrane endothelial keratoplasty (DMEK) combined with argon laser photocoagulation and intracameral 5-fluorouracil (5-FU) injection in a patient with epithelial downgrowth after cataract surgery.

Methods:

Case report and review of the literature.

Results:

A 77-year-old female underwent uneventful cataract surgery using a clear corneal incision in her left eye. Six months after surgery, an epithelial cell sheet began to cover the posterior cornea and then spread to the anterior chamber structures, leading to anterior synechia and corectopia at 2 years. Argon laser photocoagulation was used to remove epithelial downgrowth on the iris surface. However, retrocorneal epithelial downgrowth gradually progressed, resulting in bullous keratopathy. DMEK with intracameral 5-FU injection was performed to remove epithelial tissue and replace the diseased endothelium with healthy endothelium. One year after surgery, her vision improved to 20/50 and the endothelial cell count was 1,643 cells/mm2 in her left eye. There were no further complications or recurrence of epithelial downgrowth.

Conclusions:

DMEK with preoperative argon laser and intraoperative 5-FU is a useful option for the treatment of diffuse epithelial downgrowths.
Clinical, histological, and molecular risk factors for cancer recurrence in patients with stage II colon cancer
Authors: Touchefeu Yann , Provost-Dewitte Marie , Lecomte Thierry , Morel Alain , Valo Isabelle , Mosnier Jean-François , Bossard Céline , Eugène Juliette , Duchalais Emilie , Chetritt Jérôme , Guyetant Serge , Bézieau Stéphane , Senellart Hélène , Caulet Morgane , Cauchin Estelle , Matysiak-Budnik Tamara
Published: September 2016

Introduction

The assessment of risk factors of cancer recurrence in patients with stage II colon cancer (CC) is crucial. Our aim was to study the clinical, histological, and molecular features associated with 3-year disease-free survival in a series of consecutive patients with stage II CC treated in three regional digestive oncology centers.

Methods

Clinical and histological data of all patients after curative surgery for stage II CC, treated from 2001 until 2009, were collected retrospectively. Histological samples were obtained and tested prospectively for microsatellite instability using fluorescent PCR amplification. Cox proportional hazards regression models were used to calculate P values, hazard ratios (HRs), and 95% confidence intervals (CIs).

Results

Among 195 patients studied, 22 (11%) had disease recurrence during the 3-year period following diagnosis. On multivariate analysis, only low number of lymph nodes (HR=3.81, 95% CI: 1.19–12.19, P=0.02) and T4 status (HR=5.49, 95% CI: 1.06–28.43, P=0.04) were associated significantly with an increased risk of relapse.

Conclusion

In this series of stage II CC patients, only T4 status and low number of lymph nodes were independent risk factors for poor 3-year disease-free survival, suggesting that patients with these features should be considered for adjuvant chemotherapy.