bluuebunny/crossref_metadata_2025 huggingface dataset:
Traveling wave solutions of degenerate coupled Korteweg-de Vries equation
Authors: Gürses Metin , Pekcan Aslı
Published: September 2014

We give a detailed study of the traveling wave solutions of (ℓ = 2) Kaup-Boussinesq type of coupled KdV equations. Depending upon the zeros of a fourth degree polynomial, we have cases where there exist no nontrivial real solutions, cases where asymptotically decaying to a constant solitary wave solutions, and cases where there are periodic solutions. All such possible solutions are given explicitly in the form of Jacobi elliptic functions. Graphs of some exact solutions in solitary wave and periodic shapes are exhibited. Extension of our study to the cases ℓ = 3 and ℓ = 4 are also mentioned.
Optical re-injection in cavity-enhanced absorption spectroscopy
Authors: Leen J. Brian , O’Keefe Anthony
Published: September 2014

Non-mode-matched cavity-enhanced absorption spectrometry (e.g., cavity ringdown spectroscopy and integrated cavity output spectroscopy) is commonly used for the ultrasensitive detection of trace gases. These techniques are attractive for their simplicity and robustness, but their performance may be limited by the reflection of light from the front mirror and the resulting low optical transmission. Although this low transmitted power can sometimes be overcome with higher power lasers and lower noise detectors (e.g., in the near-infrared), many regimes exist where the available light intensity or photodetector sensitivity limits instrument performance (e.g., in the mid-infrared). In this article, we describe a method of repeatedly re-injecting light reflected off the front mirror of the optical cavity to boost the cavity's circulating power and deliver more light to the photodetector and thus increase the signal-to-noise ratio of the absorption measurement. We model and experimentally demonstrate the method's performance using off-axis cavity ringdown spectroscopy (OA-CRDS) with a broadly tunable external cavity quantum cascade laser. The power coupled through the cavity to the detector is increased by a factor of 22.5. The cavity loss is measured with a precision of 2 × 10−10 cm−1/$\sqrt {{\rm Hz;}}$ Hz ; an increase of 12 times over the standard off-axis configuration without reinjection and comparable to the best reported sensitivities in the mid-infrared. Finally, the re-injected CRDS system is used to measure the spectrum of several volatile organic compounds, demonstrating the improved ability to resolve weakly absorbing spectroscopic features.
Energy eigenfunctions for position-dependent mass particles in a new class of molecular Hamiltonians
Authors: Christiansen H. R. , Cunha M. S.
Published: September 2014

Based on recent results on quasi-exactly solvable Schrodinger equations, we review a new phenomenological potential class lately reported. In the present paper, we consider the quantum differential equations resulting from position-dependent mass (PDM) particles. We first focus on the PDM version of the hyperbolic potential V(x) = asech2x + bsech4x, which we address analytically with no restrictioon the parameters and the energies. This is the celebrated Manning potential, a double-well widely used in molecular physics, until now not investigated for PDM. We also evaluate the PDM version of the sixth power hyperbolic potential V(x) = asech6x + bsech4x for which we could find exact expressions under some special settings. Finally, we address a triple-well case V(x) = asech6x + bsech4x + csech2x of particular interest for its connection to the new trends in atomtronics. The PDM Schrodinger equations studied in the present paper yield analytical eigenfunctions in terms of local Heun functions in its confluents forms. In all the cases PDM particles are more likely tunneling than ordinary ones. In addition, it is observed a merging of eigenstates when the mass becomes nonuniform.
Hydrodynamic instabilities in beryllium targets for the National Ignition Facility
Authors: Yi S. A. , Simakov A. N. , Wilson D. C. , Olson R. E. , Kline J. L. , Clark D. S. , Hammel B. A. , Milovich J. L. , Salmonson J. D. , Kozioziemski B. J. , Batha S. H.
Published: September 2014

Beryllium ablators offer higher ablation velocity, rate, and pressure than their carbon-based counterparts, with the potential to increase the probability of achieving ignition at the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)]. We present here a detailed hydrodynamic stability analysis of low (NIF Revision 6.1) and high adiabat NIF beryllium target designs. Our targets are optimized to fully utilize the advantages of beryllium in order to suppress the growth of hydrodynamic instabilities. This results in an implosion that resists breakup of the capsule, and simultaneously minimizes the amount of ablator material mixed into the fuel. We quantify the improvement in stability of beryllium targets relative to plastic ones, and show that a low adiabat beryllium capsule can be at least as stable at the ablation front as a high adiabat plastic target.
Unexpected shear strength change in magnetorheological fluids
Authors: Tian Yu , Chen KaiKai , Shan Lei , Zhang Xiangjun , Meng Yonggang
Published: September 2014

Smart materials of magnetorheological (MR) fluids could be turned from a liquid state into a solid state, which solidification extent or shear strength often increases monotonically with the applied magnetic field. In this study, the shear stress of a dilute MR fluid decreased with increasing applied magnetic field at a constant shear rate. The dynamic shear stress was significantly higher than the stable counterpart at medium magnetic fields. They are ascribed to the slow particle structure transformation. A higher shear rate and particle volume fraction could reduce the transient time and the shear strength difference.
Intrinsic momentum generation by a combined neoclassical and turbulence mechanism in diverted DIII-D plasma edge
Authors: Seo Janghoon , Chang C. S. , Ku S. , Kwon J. M. , Choe W. , Müller Stefan H.
Published: September 2014

Fluid Reynolds stress from turbulence has usually been considered to be responsible for the anomalous toroidal momentum transport in tokamak plasma. Experiment by Müller et al. [Phys. Rev. Lett. 106, 115001 (2011)], however, reported that neither the observed edge rotation profile nor the inward momentum transport phenomenon at the edge region of an H-mode plasma could be explained by the fluid Reynolds stress measured with reciprocating Langmuir-probe. The full-function gyrokinetic code XGC1 is used to explain, for the first time, Müller et al.'s experimental observations. It is discovered that, unlike in the plasma core, the fluid Reynolds stress from turbulence is not sufficient for momentum transport physics in plasma edge. The “turbulent neoclassical” physics arising from the interaction between kinetic neoclassical orbit dynamics and plasma turbulence is key in the tokamak edge region across the plasma pedestal into core.
Bicolor Mn-doped CuInS2/ZnS core/shell nanocrystals for white light-emitting diode with high color rendering index
Authors: Huang Bo , Dai Qian , Zhuo Ningze , Jiang Qingsong , Shi Fenghua , Wang Haibo , Zhang Huichao , Liao Chen , Cui Yiping , Zhang Jiayu
Published: September 2014

We synthesized bicolor Mn-doped CuInS2 (CIS)/ZnS core/shell nanocrystals (NCs), in which Mn2+ ions and the CIS core were separated with a ZnS layer, and both Mn2+ ions and CIS cores could emit simultaneously. Transmission electron microscopy and powder X-ray diffraction measurements indicated the epitaxial growth of ZnS shell on the CuInS2 core, and electron paramagnetic resonance spectrum indicated that Mn2+ ions were on the lattice points of ZnS shell. By integrating these bicolor NCs with commercial InGaN-based blue-emitting diodes, tricolor white light-emitting diodes with color rendering index of 83 were obtained.
A passively tunable acoustic metamaterial lens for selective ultrasonic excitation
Authors: Zhu H. , Semperlotti F.
Published: September 2014

In this paper, we present an approach to ultrasonic beam-forming and beam-steering in structures based on the concept of embedded acoustic metamaterial lenses. The lens design exploits the principle of acoustic drop-channel that enables the dynamic coupling of multiple ultrasonic waveguides at selected frequencies. In contrast with currently available technology, the embedded lens allows exploiting the host structure as a key component of the transducer system therefore enabling directional excitation by means of a single ultrasonic transducer. The design and the performance of the lens are numerically investigated by using Plane Wave Expansion and Finite Difference Time Domain techniques applied to bulk structures. Then, the design is experimentally validated on a thin aluminum plate waveguide where the lens is implemented by through-holes. The dynamic response of the embedded lens is estimated by reconstructing, via Laser Vibrometry, the velocity field induced by a single source located at the center of the lens.
Plasmonic modification of electron-longitudinal-optical phonon coupling in Ag-nanoparticle embedded InGaN/GaN quantum wells
Authors: Llopis Antonio , Pereira Sérgio M. S. , Watson Ian M. , Neogi Arup
Published: September 2014

Surface plasmon enhanced GaN and InGaN quantum wells (QWs) show promise for use as room-temperature light emitters. The effectiveness of the plasmon enhancement, however, is limited by the strong electron/hole and longitudinal optical phonon coupling found in the III-V nitrides. The electron-phonon coupling within semiconductor QWs has been modified using silver nanoparticles embedded within the QWs. Direct evidence is provided for this change via confocal Raman spectroscopy of the samples. This evidence is augmented by Angle-dependent photoluminescence experiments which show the alteration of the electron-phonon coupling strength through measurement of the emitted phonon replicas. Together these demonstrate a direct modification of carrier-phonon interactions within the system, opening up the possibility of controlling the coupling strength to produce high-efficiency room-temperature light emitters.
Investigations of BaxSr1−xTiO3 ceramics and powders prepared by direct current arc discharge technique
Authors: Li Shuangbin , Yao Ying , Yuzyuk Yu. I. , Jia Yongzhong , Wang Xiaohan , Xie Shaolei , Jing Yan
Published: September 2014

BaxSr1−xTiO3 ceramics with x ranging from 0 to 1 were prepared by direct current arc discharge technique and studied by means of x-ray diffraction (XRD) and Raman spectroscopy. The cubic-tetragonal ferroelectric phase transition in BaxSr1−xTiO3 ceramics was found to occur at x ≈ 0.75. XRD investigation of as-grown BaTiO3 ceramics revealed co-existence of tetragonal and hexagonal modifications with a small amount of impurity phase BaTi4O9. No evidences of hexagonal phase were observed in Raman spectra of as-grown BaTiO3 ceramics, while Raman peaks related to hexagonal phase were clearly observed in the spectrum of fine-grain powders prepared from the same ceramics. A core-shell model for BaTiO3 ceramics prepared by direct current arc discharge technique is proposed. Absence of the hexagonal phase in any BaxSr1−xTiO3 solid solution with x < 1 is discussed in the frame of specific atomic arrangement.
Microfluidic channel structures speed up mixing of multiple emulsions by a factor of ten
Authors: Land Kevin J. , Mbanjwa Mesuli , Korvink Jan G.
Published: September 2014

We present a novel use for channel structures in microfluidic devices, whereby two two-phase emulsions, one created on-chip, the other off-chip, are rapidly mixed with each other in order to allow for the coalescence of one emulsion with the other. This approach has been motivated by the difficulty in introducing aqueous cross linking agents into droplets by utilising conventional approaches. These conventional approaches include continuous introduction of the different aqueous reagents before droplet formation or alternatively formation of individual droplets of each reagent and subsequent droplet merging later in the microfluidic device. We show that our approach can decrease the mixing time for these fluidic systems by a factor greater than 10 times when compared to a standard microfluidic channel without structures, thereby also allowing for additional reaction time within the microfluidic device. This method shows an application for microfluidic channel structures not before demonstrated, also demonstrating an alternative method for introducing reagents such as cross linkers which link polymer chains to form particles, and provides an example where enzymes are immobilized in monodisperse particles.
A microfluidic platform for quantitative analysis of cancer angiogenesis and intravasation
Authors: Lee Hyunjae , Park Woohyun , Ryu Hyunryul , Jeon Noo Li
Published: September 2014

Understanding the mechanism behind cancer metastasis is a major challenge in cancer biology. Several in vitro models have been developed to mimic a cancer microenvironment by engineering cancer–endothelial cell (EC) and cancer-stromal cell interactions. It has been challenging to realistically mimic angiogenesis, intravasation, and extravasation using macro-scale approaches but recent progress in microfluidics technology has begun to yield promising results. We present a metastasis chip that produce microvessels, where EC and stromal cells can be patterned in close proximity to tumor cells. The vessels are formed following a natural morphogenic process and have smooth boundaries with proper cell-cell junctions. The engineered microvessels are perfusable and have well-defined openings toward inlet and outlet channels. The ability to introduce cancer cells into different locations bordering to the microvessel wall allowed generation and maintenance of appropriate spatial gradients of growth factors and attractants. Cancer angiogenesis and its inhibition by anti-vascular endothelial growth factor (bevacizumab) treatment were successfully reproduced in the metastasis chip. Cancer intravasation and its modulation by treatment of tumor necrosis factor-α were also modeled. Compared to other models, the unique design of the metastasis chip that engineers a clear EC-cancer interface allows precise imaging and quantification of angiogenic response as well as tumor cell trans-endothelial migration. The metastasis chip presented here has potential applications in the investigation of fundamental cancer biology as well as in drug screening.
Turbulence elasticity—A new mechanism for transport barrier dynamics
Authors: Guo Z. B. , Diamond P. H. , Kosuga Y. , Gürcan Ö. D.
Published: September 2014

We present a new, unified model of transport barrier formation in “elastic” drift wave-zonal flow (DW-ZF) turbulence. A new physical quantity—the delay time (i.e., the mixing time for the DW turbulence)—is demonstrated to parameterize each stage of the transport barrier formation. Quantitative predictions for the onset of limit-cycle-oscillation (LCO) among DW and ZF intensities (also denoted as I-mode) and I-mode to high-confinement mode (H-mode) transition are also given. The LCO occurs when the ZF shearing rate (|〈v〉ZF′|) enters the regime Δωk<|〈V〉ZF′|<τcr−1, where Δωk is the local turbulence decorrelation rate and τcr is the threshold delay time. In the basic predator-prey feedback system, τcr is also derived. The I-H transition occurs when |〈V〉E×B′|>τcr−1, where the mean E × B shear flow driven by ion pressure “locks” the DW-ZF system to the H-mode by reducing the delay time below the threshold value.
Flexible pH sensors based on polysilicon thin film transistors and ZnO nanowalls
Authors: Maiolo L. , Mirabella S. , Maita F. , Alberti A. , Minotti A. , Strano V. , Pecora A. , Shacham-Diamand Y. , Fortunato G.
Published: September 2014

A fully flexible pH sensor using nanoporous ZnO on extended gate thin film transistor (EGTFT) fabricated on polymeric substrate is demonstrated. The sensor adopts the Low Temperature Polycrystalline Silicon (LTPS) TFT technology for the active device, since it allows excellent electrical characteristics and good stability and opens the way towards the possibility of exploiting CMOS architectures in the future. The nanoporous ZnO sensitive film, consisting of very thin (20 nm) crystalline ZnO walls with a large surface-to-volume ratio, was chemically deposited at 90 °C, allowing simple process integration with conventional TFT micro-fabrication processes compatible with wide range of polymeric substrates. The pH sensor showed a near-ideal Nernstian response (∼59 mV/pH), indicating an ideality factor α ∼ 1 according to the conventional site binding model. The present results can pave the way to advanced flexible sensing systems, where sensors and local signal conditioning circuits will be integrated on the same flexible substrate.
Chromosome instability induced by Mps1 and p53 mutation generates aggressive lymphomas exhibiting aneuploidy-induced stress
Authors: Foijer Floris , Xie Stephanie Z. , Simon Judith E. , Bakker Petra L. , Conte Nathalie , Davis Stephanie H. , Kregel Eva , Jonkers Jos , Bradley Allan , Sorger Peter K.
Published: September 2014

Significance

Normal cells rarely missegregate chromosomes, but the majority of cancer cells have a chromosomal instability (CIN) phenotype that makes errors more common and results in abnormal chromosomal content (aneuploidy). Although aneuploidy promotes transformation via gain of oncogenes and loss of tumor suppressors, it also slows cell proliferation and disrupts metabolic homeostasis. Aneuploidy therefore represents a liability as well as a source of selective advantage for cancer cells. We provoked CIN in murine T cells by weakening the spindle-assembly checkpoint and then studied the consequences. We found that CIN dramatically accelerates cancer in a genetically predisposed background and that the resulting aneuploid cancers are metabolically deranged, a vulnerability that may open new avenues to treating aneuploid cancers.
Genetic variants of ApoE and ApoER2 differentially modulate endothelial function
Authors: Ulrich Victoria , Konaniah Eddy S. , Herz Joachim , Gerard Robert D. , Jung Eunjeong , Yuhanna Ivan S. , Ahmed Mohamed , Hui David Y. , Mineo Chieko , Shaul Philip W.
Published: September 2014

Significance

Why genetic variants of the circulating protein apolipoprotein E (apoE) or its receptor apoliprotein E receptor 2 (ApoER2) confer greater cardiovascular disease risk is poorly understood. We report that in endothelial cells, which are the guardian cells of the vascular wall, the most common form of apoE, apoE3, activates ApoER2 to favorably impact endothelial function. The risk-enhancing apoE variant apoE4 lacks this capacity and instead inhibits apoE3–ApoER2 action, and a risk-conferring ApoER2 variant is nonfunctional in endothelium. Evidence is obtained in mice that the genetic variants adversely impact endothelial repair and related vascular disease severity. From these discoveries personalized treatment strategies may be developed to protect individuals with risk-altering apoE or ApoER2 variants, which comprise approximately 15% of the population.
Translation initiation factor eIF4F modifies the dexamethasone response in multiple myeloma
Authors: Robert Francis , Roman William , Bramoullé Alexandre , Fellmann Christof , Roulston Anne , Shustik Chaim , Porco John A. , Shore Gordon C. , Sebag Michael , Pelletier Jerry
Published: September 2014

Significance

Multiple myeloma (MM) is a cancer that develops in the bone marrow and remains incurable to this day. It is a cancer type that shows hallmarks of deregulated protein synthesis control. To uncover new vulnerabilities in this disease, we performed a focused RNAi screen to identify components of the translation apparatus that, when depleted, would sensitize tumor cells to dexamethasone (DEX), a component of frontline therapy in this cancer. We found that suppression of eukaryotic initiation factor 4F, a heterotrimeric complex required for cap-dependent translation initiation, is a modifier of the DEX response in MM. Our efforts uncover a previously unidentified vulnerability in MM that should be explored clinically.
Phospholipase Cδ1 induces E-cadherin expression and suppresses malignancy in colorectal cancer cells
Authors: Satow Reiko , Hirano Tamaki , Batori Ryosuke , Nakamura Tomomi , Murayama Yumi , Fukami Kiyoko
Published: September 2014

Significance

We found that expression of phospholipase Cδ1 (PLCδ1) is down-regulated in colorectal cancer (CRC) cells compared with normal colon epithelium. Ectopic expression of PLCδ1 in CRC cells induced expression of E-cadherin, a tumor-suppressive cell–cell adhesion molecule, whereas knockdown of PLCδ1 repressed E-cadherin expression. Moreover, PLCδ1 overexpression reduced the malignant phenotypes of CRC. We also identified that PLCδ1 expression is repressed by the Kirsten rat sarcoma viral oncogene homolog (
KRAS
)/mitogen-activated protein kinase kinase (MEK) pathway, which is constitutively activated in many of CRC cells. Furthermore, PLCδ1 expression suppressed the phosphorylation of ERK1/2, which is an MEK target, by E-cadherin induction. These data suggest that PLCδ1 has tumor-suppressive functions in CRC through E-cadherin induction and KRAS/MEK/ERK signal attenuation. These findings could provide a valuable strategy for CRC treatment.
Mixtures of opposing phosphorylations within hexamers precisely time feedback in the cyanobacterial circadian clock
Authors: Lin Jenny , Chew Justin , Chockanathan Udaysankar , Rust Michael J.
Published: September 2014

Significance

Many organisms possess biological clocks that schedule their behavior throughout the day. To function properly, these clocks must maintain a period near 24 hours despite fluctuations in conditions. In a simple three-protein oscillator from cyanobacteria, timing information is stored in KaiC, a phosphorylated protein which forms hexameric rings. We show that the feedback loop that allows oscillation depends cooperatively on phosphorylation throughout the KaiC hexamer. Two phosphorylation sites with different kinetics have opposing effects, and this creates a sharp transition between the day and night states of the ring. This mechanism, based on opposing modifications, generates circadian rhythms across the relevant range of protein stochiometries and may be used generally in biochemical networks for precise timing.
Human oxygen sensing may have origins in prokaryotic elongation factor Tu prolyl-hydroxylation
Authors: Scotti John S. , Leung Ivanhoe K. H. , Ge Wei , Bentley Michael A. , Paps Jordi , Kramer Holger B. , Lee Joongoo , Aik WeiShen , Choi Hwanho , Paulsen Steinar M. , Bowman Lesley A. H. , Loik Nikita D. , Horita Shoichiro , Ho Chia-hua , Kershaw Nadia J. , Tang Christoph M. , Claridge Timothy D. W. , Preston Gail M. , McDonough Michael A. , Schofield Christopher J.
Published: September 2014

Significance

The Fe(II)- and 2-oxoglutarate (2OG)-dependent hypoxia-inducible transcription factor prolyl-hydroxylases play a central role in human oxygen sensing and are related to other prolyl-hydroxylases involved in eukaryotic collagen biosynthesis and ribosomal modification. The finding that a PHD-related prolyl-hydroxylase inPseudomonas spp.regulates pyocyanin biosynthesis supports prokaryotic origins for the eukaryotic prolyl-hydroxylases. The identification of the switch I loop of elongation factor Tu (EF-Tu) as aPseudomonasprolyl-hydroxylase domain containing protein (PPHD) substrate provides evidence of roles for 2OG oxygenases in both translational and transcriptional regulation. A structure of the PPHD:EF-Tu complex, the first to the authors' knowledge of a 2OG oxygenase with its intact protein substrate, reveals that major conformational changes occur in both PPHD and EF-Tu and will be useful in the design of new prolyl-hydroxylase inhibitors.
Nup98 promotes antiviral gene expression to restrict RNA viral infection in
Drosophila
Authors: Panda Debasis , Pascual-Garcia Pau , Dunagin Margaret , Tudor Matthew , Hopkins Kaycie C. , Xu Jie , Gold Beth , Raj Arjun , Capelson Maya , Cherry Sara
Published: September 2014

Significance

The innate immune system is a highly conserved mode of defense that induces gene expression programs to restrict microbial infections. However, much remains unknown about how the target genes are poised for their rapid induction. Using a
Drosophila
model, we demonstrate that Nup98 plays an essential antiviral role in insects against human insect-borne viruses. Although Nup98 is known for its role in nuclear-cytoplasmic transport, our data suggest that this antiviral function is not at the nuclear pore, rather at promoters controlling expression of a subset of virus-induced genes. Our findings suggest that the Nup98 primes virus-stimulated genes by regulating the occupancy of active RNA polymerase at these promoters poising them for rapid induction, thereby coordinating a robust and complex antiviral response.
Optogenetic activation of septal cholinergic neurons suppresses sharp wave ripples and enhances theta oscillations in the hippocampus
Authors: Vandecasteele Marie , Varga Viktor , Berényi Antal , Papp Edit , Barthó Péter , Venance Laurent , Freund Tamás F. , Buzsáki György
Published: September 2014

Significance

Theta oscillations are a prominent rhythm of the brain occurring during active behavior and rapid eye movement sleep and thought to provide the temporal frame for the encoding of information. Acetylcholine modulation is a major player in hippocampal theta rhythm, as demonstrated by lesion and pharmacological manipulations of cholinergic receptors, yet the link between the activity of septal cholinergic neurons and the theta rhythm is not fully understood. We used specific optogenetic stimulation of the septo-hippocampal cholinergic neurons in the anesthetized and behaving mouse to decipher the effects of cholinergic stimulation on hippocampal network activity and show that in addition to promoting theta oscillations it suppresses sharp wave ripples and peri-theta band activity.
Assembly and molecular order of two-dimensional peptoid nanosheets through the oil–water interface
Authors: Robertson Ellen J. , Olivier Gloria K. , Qian Menglu , Proulx Caroline , Zuckermann Ronald N. , Richmond Geraldine L.
Published: September 2014

Significance

Peptoid nanosheets are an emerging class of 2D nanomaterials that have the potential for use in a variety of applications ranging from molecular sensors to artificial enzymes. Because peptoids are highly designable polymers, nanosheets provide a general platform on which to display an enormous diversity of functionalities. Nanosheets are known to form through a unique monolayer compression mechanism, catalyzed by the air–water interface. Here we demonstrate that nanosheets can be formed via adsorption of peptoids at an oil–water interface. Using vibrational sum frequency spectroscopy, we show that electrostatic interactions are essential in the formation of an ordered peptoid monolayer at the interface, a critical intermediate in the nanosheet assembly pathway. These findings open the door for enhancing the complexity and functionality of 2D nanomaterials.
Electronic Recognition of Hand Hygiene Technique and Duration
Authors: Galluzzi Valerie , Herman Ted , Shumaker D. J. , Macinga D. R. , Arbogast J. W. , Segre Elena M. , Segre Alberto M. , Polgreen Philip M.
Published: September 2014

We captured 3-dimensional accelerometry data from the wrists of 116 healthcare professionals as they performed hand hygiene (HH). We then used these data to train a k-nearest-neighbors classifier to recognize specific aspects of HH technique (ie, fingertip scrub) and measure the duration of HH events.

Infect Control Hosp Epidemiol 2014;35(10):1298–1300
Protective Effect of Methicillin-Susceptible Staphylococcus aureus Carriage against Methicillin-Resistant S. aureus Acquisition in Nursing Homes: A Prospective Cross-Sectional Study
Authors: Datta Rupak , Quan Victor , Kim Diane , Peterson Ellena M. , Reynolds Courtney , Meyers Hildy , Cheung Michele , Huang Susan S.
Published: September 2014

Objective.

To evaluate whether an ecologic inverse association exists between methicillin-susceptible Staphylococcus aureus (MSSA) prevalence and methicillin-resistant S. aureus (MRSA) prevalence in nursing homes.

Methods.

We conducted a secondary analysis of a prospective cross-sectional study of S. aureus prevalence in 26 nursing homes across Orange County, California, from 2008–2011. Admission prevalence was assessed using bilateral nares swabs collected from all new residents within 3 days of admission until 100 swabs were obtained. Point prevalence was assessed from a representative sample of 100 residents. Swab samples were plated on 5% sheep blood agar and Spectra MRSA chromogenic agar. If MRSA was detected, no further tests were performed. If MRSA was not detected, blood agar was evaluated for MSSA growth. We evaluated the association between MRSA and MSSA admission and point prevalence using correlation and linear regression testing.

Results.

We collected 3,806 total swabs. MRSA and MSSA admission prevalence were not correlated (r = −0.40, P = .09). However, MRSA and MSSA point prevalence were negatively correlated regardless of whether MSSA prevalence was measured among all residents sampled (r = −0.67, P = .0002) or among those who did not harbor MRSA (r = −0.41, P = .04). This effect persisted in regression models adjusted for the percentage of residents with diabetes (β = −0.73, P = .04), skin lesions (β = −1.17, P = .002), or invasive devices (β = −1.4, P = .0006).

Conclusions.

The inverse association between MRSA and MSSA point prevalence and minimal association on admission prevalence suggest MSSA carriage may protect against MRSA acquisition in nursing homes. The minimal association on admission prevalence further suggests competition may occur during nursing home stays.

Infect Control Hosp Epidemiol 2014;35(10):1257–1262
Homotopy theory of modules over diagrams of rings
Authors: Greenlees J. , Shipley B.
Published: September 2014

Given a diagram of rings, one may consider the category of modules over them. We are interested in the homotopy theory of categories of this type: given a suitable diagram of model categories

M

(
s
)

\mathcal {M}(s)

(as

s
s

runs through the diagram), we consider the category of diagrams where the object

X
(
s
)

X(s)

at

s
s

comes from

M

(
s
)

\mathcal {M}(s)

. We develop model structures on such categories of diagrams and Quillen adjunctions that relate categories based on different diagram shapes.

Under certain conditions, cellularizations (or right Bousfield localizations) of these adjunctions induce Quillen equivalences. As an application we show that a cellularization of a category of modules over a diagram of ring spectra (or differential graded rings) is Quillen equivalent to modules over the associated inverse limit of the rings. Another application of the general machinery here is given in work by the authors on algebraic models of rational equivariant spectra. Some of this material originally appeared in the preprint “An algebraic model for rational torus-equivariant stable homotopy theory”, arXiv:1101.2511, but has been generalized here.
RCSB PDB
Mobile
: iOS and Android mobile apps to provide data access and visualization to the RCSB Protein Data Bank
Authors: Quinn Gregory B. , Bi Chunxiao , Christie Cole H. , Pang Kyle , Prlić Andreas , Nakane Takanori , Zardecki Christine , Voigt Maria , Berman Helen M. , Bourne Philip E. , Rose Peter W.
Published: September 2014

Summary: The Research Collaboratory for Structural Bioinformatics Protein Data Bank (RCSB PDB) resource provides tools for query, analysis and visualization of the 3D structures in the PDB archive. As the mobile Web is starting to surpass desktop and laptop usage, scientists and educators are beginning to integrate mobile devices into their research and teaching. In response, we have developed the RCSB PDB Mobile app for the iOS and Android mobile platforms to enable fast and convenient access to RCSB PDB data and services. Using the app, users from the general public to expert researchers can quickly search and visualize biomolecules, and add personal annotations via the RCSB PDB’s integrated MyPDB service.

Availability and implementation: RCSB PDB Mobile is freely available from the Apple App Store and Google Play ( http://www.rcsb.org ).

Contact:  pwrose@ucsd.edu
Sports and childhood brain tumors: Can I play?
Authors: Perreault Sébastien , Lober Robert M. , Davis Carissa , Stave Christopher , Partap Sonia , Fisher Paul G.
Published: September 2014

Background

It is unknown whether children with brain tumors have a higher risk of complications while participating in sports. We sought to estimate the prevalence of such events by conducting a systematic review of the literature, and we surveyed providers involved with pediatric central nervous system (CNS) tumor patients.

Methods

A systematic review of the literature in the PubMed, Scopus, and Cochrane databases was conducted for original articles addressing sport-related complications in the brain-tumor population. An online questionnaire was created to survey providers involved with pediatric CNS tumor patients about their current recommendations and experience regarding sports and brain tumors.

Results

We retrieved 32 subjects, including 19 pediatric cases from the literature. Most lesions associated with sport complications were arachnoid cysts (n = 21), followed by glioma (n = 5). The sports in which symptom onset most commonly occurred were soccer (n = 7), football (n = 5), and running (n = 5). We surveyed 111 pediatric neuro-oncology providers. Sport restriction varied greatly from none to 14 sports. Time to return to play in sports with contact also varied considerably between providers. Rationales for limiting sports activities were partly related to subspecialty. Responders reported 9 sport-related adverse events in patients with brain tumor.

Conclusions

Sport-related complications are uncommon in children with brain tumors. Patients might not be at a significantly higher risk and should not need to be excluded from most sports activities.
Reliable Detection for Bean yellow mosaic virus, Canna yellow streak virus, and Canna yellow mottle virus in Canna Varieties with Red Foliage
Authors: Chauhan Ravendra P. , Hamon Hayden F. , Rajakaruna Punsasi , Webb Mark A. , Payton Mark , Verchot Jeanmarie
Published: September 2014

Cannas grow from rhizomes to produce colorful foliage that ranges from deep burgundy, bronze, green, purple veined, and variegated. Bean yellow mosaic virus (BYMV), Canna yellow streak virus (CaYSV), and Canna yellow mottle virus (CaYMV) are problematic viruses infecting cannas. Their disease characteristics have been reported in green-leaved varieties. This study investigated if rhizome planting stocks can be a source of virus infection. PCR and RT-PCR tests identified BYMV, CaYSV, and CaYMV sequences in 20 canna rhizomes and newly emerging leaves. Immunosorbent electron microscopy tests identified filamentous potyvirus particles in rhizome and leaf tissue. In addition, disease characteristics were examined in a subset of red-leaved varieties ‘Australia’, ‘Burning Ember’, and ‘Red Futurity’ planted in pots in the greenhouse. Plants were assigned identifying codes, visual disease ratings, and samples were taken for RT-PCR and PCR virus detection assays. Statistical analysis was carried out to compare disease ratings with RT-PCR and PCR test results. Visual assessment was found to be not a reliable indicator of virus infection in ‘Australia’ and ‘Burning Ember’ plants. ‘Red Futurity’ produced the most obvious pattern of mosaic disease and virus symptoms were easier to identify in this variety. This study demonstrated that visual assessment was an ineffective method for disease identification for the red-leaved varieties. Growers would be well advised to utilize molecular testing to identify infected plants to aid in the clean-up of the crop.
Baseline Sensitivity of Pyraclostrobin and Toxicity of SHAM to Sclerotinia sclerotiorum
Authors: Liang Hong-Jie , Di Ya-Li , Li Jin-Li , You Hong , Zhu Fu-Xing
Published: September 2014

Sclerotinia sclerotiorum is a cosmopolitan plant pathogen notable for its wide host range. The quinone outside inhibitor (QoI) fungicide pyraclostrobin has not been registered for control of S. sclerotiorum in China. In this study, baseline sensitivity of pyraclostrobin was established based on effective concentration for 50% inhibition of mycelial growth (EC50) values of 153 isolates of S. sclerotiorum collected from five provinces of China and toxicity of alternative oxidase inhibitor salicylhydroxamic acid (SHAM) to S. sclerotiorum was determined. Results showed that the frequency distribution of EC50 values of the 153 isolates was unimodal but with a right-hand tail. The mean EC50 value was 0.1027 μg/ml and the range of EC50 values was 0.0124 to 0.6324 μg/ml. Applied as a preventive fungicide in pot experiments, pyraclostrobin at 5, 15, and 45 μg/ml provided control efficacies of 61, 77, and 100%, respectively. There was no positive cross-resistance between pyraclostrobin and carbendazim or dimethachlon. EC50 values for SHAM against four isolates of S. sclerotiorum were 44.4, 51.8, 54.4, and 68.7 μg/ml. SHAM at 20 μg/ml could significantly increase not only the inhibitory effect of pyraclostrobin on mycelial growth on potato dextrose agar media but also the control efficacy in planta. These results indicated that SHAM should not be added into artificial media in in vitro assay of S. sclerotiorum sensitivity to pyraclostrobin. This has broad implications for assay of sensitivity of fungal pathogen to QoI fungicides.
Choroidal Ganglioneuroma and Orbital Plexiform Neurofibroma Presenting as Buphthalmos in an Infant With Neurofibromatosis Type 1
Authors: Goyal Sunali , Park Abraham , Zeglam Ahmaida , Brown Harry , Pemberton John D.
Published: September 2014

Neurofibromatosis type 1 (NF-1) is an autosomal dominant familial tumor predisposition syndrome characterized by the growth of benign and malignant tumors involving the peripheral and central nervous system. In the following report, the authors describe a case of a 1-year-old child with NF-1, who underwent enucleation for a blind, proptotic, painful eye with subsequent histopathological examination revealing choroidal ganglioneuroma, a very rare entity.
Orbital and Periorbital Extension of Congenital Dacryocystoceles: Suggested Mechanism and Management
Authors: Bernardini Francesco P. , Cetinkaya Altug , Capris Paolo , Rossi Andrea , Kaynak Pelin , Katowitz James A.
Published: September 2014

Orbital and periorbital extension of congenital dacryocystoceles is rarely observed in neonatal infants. The authors describe 4 cases of congenital dacryocystocele that presented with extension to the orbital and periorbital regions. The first 3 newborns underwent marsupialization of the orbital and periorbital dacryocystoceles with aspiration of the purulent material followed by nasolacrimal duct probing after radiographic evidence of diffuse orbital or periorbital expansion. The fourth patient was successfully treated with an external dacryocystorhinostomy with excision of the enlarged cystic walls. Transconjunctival orbitotomy with sac marsupialization followed by nasolacrimal intubation can provide immediate and permanent resolutions of this unusual complication in most instances. External dacryocystorhinostomy may be required, however, when the orbital or periorbital dacryocystocele is complicated by acute or recurrent dacryocystitis.
Magnitude of Anemia at Discharge Increases 30-Day Hospital Readmissions
Authors: Koch Colleen G. , Li Liang , Sun Zhiyuan , Hixson Eric D. , Tang Anne , Chagin Kevin , Kattan Michael , Phillips Shannon C. , Blackstone Eugene H. , Henderson J. Michael
Published: September 2014

Background

Anemia during hospitalization is associated with poor health outcomes. Does anemia at discharge place patients at risk for hospital readmission within 30 days of discharge? Our objectives were to examine the prevalence and magnitude of anemia at hospital discharge and determine whether anemia at discharge was associated with 30-day readmissions among a cohort of hospitalizations in a single health care system.

Methods

From January 1, 2009, to August 31, 2011, there were 152,757 eligible hospitalizations within a single health care system. The endpoint was any hospitalization within 30 days of discharge. The University HealthSystem Consortium's clinical database was used for demographics and comorbidities; hemoglobin values are from the hospitals' electronic medical records, and readmission status was obtained from the University HealthSystem Consortium administrative data systems. Mild anemia was defined as hemoglobin of greater than 11 to less than 12 g/dl in women and greater than 11 to less than 13 g/dl in men; moderate, greater than 9 to less than or equal to 11 g/dl; and severe, less than or equal to 9 g/dl. Logistic regression was used to assess the association of anemia and 30-day readmissions adjusted for demographics, comorbidity, and hospitalization type.

Results

Among 152,757 hospitalizations, 72% of patients were discharged with anemia: 31,903 (21%), mild; 52,971 (35%), moderate; and 25,522 (17%), severe. Discharge anemia was associated with severity-dependent increased odds for 30-day hospital readmission compared with those without anemia: for mild anemia, 1.74 (1.65–1.82); moderate anemia, 2.76 (2.64–2.89); and severe anemia, 3.47 (3.30–3.65), P < 0.001.

Conclusions

Anemia at discharge is associated with a severity-dependent increased risk for 30-day readmission. A strategy focusing on anemia treatment care paths during index hospitalization offers an opportunity to influence subsequent readmissions.
Video demonstrations seed alternative problem-solving techniques in wild common marmosets
Authors: Gunhold Tina , Whiten Andrew , Bugnyar Thomas
Published: September 2014

Studies of social learning and tradition formation under field conditions have recently gained momentum, but suffer from the limited control of socio-ecological factors thought to be responsible for transmission patterns. The use of artificial visual stimuli is a potentially powerful tool to overcome some of these problems. Here, in a field experiment, we used video images of unfamiliar conspecifics performing virtual demonstrations of foraging techniques. We tested 12 family groups of wild common marmosets. Six groups received video demonstrations (footage of conspecifics either pulling a drawer open or pushing a lid upwards, in an ‘artificial fruit’); the other six groups served as controls (exposed to a static image of a conspecific next to the fruit). Subjects in video groups were more manipulative and successful in opening the fruit than controls; they were also more likely to use the technique they had witnessed and thus could serve as live models for other family members. To our knowledge, this is the first study that used video demonstrations in the wild and demonstrated the potent force of social learning, even from unfamiliar conspecifics, under field conditions.
Peter Gray. 25 August 1926 — 7 June 2012
Authors: Scott S. K.
Published: September 2014

Peter Gray was an internationally recognized research leader in the areas of combustion chemistry and chemical instabilities. His undergraduate education and early research career were in Cambridge. He moved to the University of Leeds in 1955, becoming Head of Physical Chemistry there in 1965. In 1988 he returned to Cambridge as Master of Gonville and Caius College. Peter’s scientific contributions covered experimental and theoretical studies of chemical and thermal instabilities in combustion systems and in isothermal systems exhibiting autocatalysis, and of flames and chemical waves. His work provided the framework for understanding the thermokinetic origin of cool flames and multiple-stage ignitions and for the onset of ignition and oscillations in chemical systems more generally. He served on a series of important government committees and held major office for the Faraday Society and the Combustion Institute. He published more than 300 research articles and one monograph and was awarded a series of major prizes, including the Marlow Medal, the Bernard Lewis Gold Medal and the Italgas Prize.
Cryptic iridescence in a fossil weevil generated by single diamond photonic crystals
Authors: McNamara Maria E. , Saranathan Vinod , Locatelli Emma R. , Noh Heeso , Briggs Derek E. G. , Orr Patrick J. , Cao Hui
Published: September 2014

Nature's most spectacular colours originate in integumentary tissue architectures that scatter light via nanoscale modulations of the refractive index. The most intricate biophotonic nanostructures are three-dimensional crystals with opal, single diamond or single gyroid lattices. Despite intense interest in their optical and structural properties, the evolution of such nanostructures is poorly understood, due in part to a lack of data from the fossil record. Here, we report preservation of single diamond (
Fd
-3
m
) three-dimensional photonic crystals in scales of a 735 000 year old specimen of the brown Nearctic weevil
Hypera diversipunctata
from Gold Run, Canada, and in extant conspecifics. The preserved red to green structural colours exhibit near-field brilliancy yet are inconspicuous from afar; they most likely had cryptic functions in substrate matching. The discovery of pristine fossil examples indicates that the fossil record is likely to yield further data on the evolution of three-dimensional photonic nanostructures and their biological functions.
Three-dimensionally deformable, highly stretchable, permeable, durable and washable fabric circuit boards
Authors: Li Qiao , Tao Xiao Ming
Published: September 2014

This paper reports fabric circuit boards (FCBs), a new type of circuit boards, that are three-dimensionally deformable, highly stretchable, durable and washable ideally for wearable electronic applications. Fabricated by using computerized knitting technologies at ambient dry conditions, the resultant knitted FCBs exhibit outstanding electrical stability with less than 1% relative resistance change up to 300% strain in unidirectional tensile test or 150% membrane strain in three-dimensional ball punch test, extraordinary fatigue life of more than 1 000 000 loading cycles at 20% maximum strain, and satisfactory washing capability up to 30 times. To the best of our knowledge, the performance of new FCBs has far exceeded those of previously reported metal-coated elastomeric films or other organic materials in terms of changes in electrical resistance, stretchability, fatigue life and washing capability as well as permeability. Theoretical analysis and numerical simulation illustrate that the structural conversion of knitted fabrics is attributed to the effective mitigation of strain in the conductive metal fibres, hence the outstanding mechanical and electrical properties. Those distinctive features make the FCBs particularly suitable for next-to-skin electronic devices. This paper has further demonstrated the application potential of the knitted FCBs in smart protective apparel for
in situ
measurement during ballistic impact.
Dimorphic development inStreblospio benedicti:genetic analysis of morphological differences between larval types
Authors: Zakas Christina , Rockman Matthew V.
Published: September 2014

The marine polychaeteStreblospio benedictiexhibits two distinct larval types, making it a model for the study of developmental evolution. Females produce either large eggs or small ones, which develop into distinct lecithotrophic or planktotrophic larvae with concomitant morphological and life-history differences. Here, we investigate the inheritance of key morphological traits that distinguish the larval types. We use genetic crosses to establish the influence of maternal and zygotic differences on larval phenotypes. We find a large maternal effect on larval size and the number of larval chaetae, while the number and length of these chaetae are also strongly influenced by zygotic genotype. Interestingly, the distribution of larval phenotypes produced by these crosses suggests traits intermediate to the two parental types should not be uncommon. Yet, despite gene flow between the types in natural populations, such intermediates are rarely found in nature, suggesting that selection may be maintaining distinct larval modes.