bluuebunny/crossref_metadata_2025 huggingface dataset:
Momentum transport process in the quasi self-similar region of free shear mixing layer
Authors: Takamure K. , Ito Y. , Sakai Y. , Iwano K. , Hayase T.
Published: January 2018

In this study, we performed a direct numerical simulation (DNS) of a spatially developing shear mixing layer covering both developing and developed regions. The aim of this study is to clarify the driving mechanism and the vortical structure of the partial counter-gradient momentum transport (CGMT) appearing in the quasi self-similar region. In the present DNS, the self-similarity is confirmed in x/L ≥ 0.67 (x/δU0 ≥ 137), where L and δU0 are the vertical length of the computational domain and the initial momentum thickness, respectively. However, the trend of CGMT is observed at around kδU = 0.075 and 0.15, where k is the wavenumber, δU is the normalized momentum thickness at x/L = 0.78 (x/δU0 = 160), and kδU = 0.075 corresponds to the distance between the vortical/stretching regions of the coherent structure. The budget analysis for the Reynolds shear stress reveals that it is caused by the pressure diffusion term at the off-central region and by −p(∂u/∂y)¯ in the pressure-strain correlation term at the central region. As the flow moves toward the downstream direction, the appearance of those terms becomes random and the unique trend of CGMT at the specific wavenumber bands disappears. Furthermore, we investigated the relationship between the CGMT and vorticity distribution in the vortex region of the mixing layer, in association with the spatial development. In the upstream location, the high-vorticity region appears in the boundary between the areas of gradient momentum transport and CGMT, although the high-vorticity region is not actively producing turbulence. The negative production area gradually spreads by flowing toward the downstream direction, and subsequently, the fluid mass with high-vorticity is transported from the forehead stretching region toward the counter-gradient direction. In this location, the velocity fluctuation in the high-vorticity region is large and turbulence is actively produced. In view of this, the trend of negative production appears in the flow where the turbulence production and non-turbulent regions mix. Then, the non-turbulent region and CGMT almost simultaneously disappear in the fully developed region.
Electro-suppression of water nano-droplets’ solidification in no man’s land: Electromagnetic fields’ entropic trapping of supercooled water
Authors: Nandi Prithwish K. , Burnham Christian J. , English Niall J.
Published: January 2018

Understanding water solidification, especially in “No Man’s Land” (NML) (150 K < T < 235 K) is crucially important (e.g., upper-troposphere cloud processes) and challenging. A rather neglected aspect of tropospheric ice-crystallite formation is inevitably present electromagnetic fields’ role. Here, we employ non-equilibrium molecular dynamics of aggressively quenched supercooled water nano-droplets in the gas phase under NML conditions, in externally applied electromagnetic (e/m) fields, elucidating significant differences between effects of static and oscillating fields: although static fields induce “electro-freezing,” e/m fields exhibit the contrary – solidification inhibition. This anti-freeze action extends not only to crystal-ice formation but also restricts amorphisation, i.e., suppression of low-density amorphous ice which forms otherwise in zero-field NML environments. E/m-field applications maintain water in the deeply supercooled state in an “entropic trap,” which is ripe for industrial impacts in cryo-freezing, etc.
Estimation of the plasma blob occurrence rate
Authors: Häcker R. , Fuchert G. , Carralero D. , Manz P.
Published: January 2018

As part of the blob duty cycle, the blob detection rate, also called the blob occurrence rate or simply blob frequency, is of critical importance to predict the impact of plasma blobs on plasma wall interaction and modification of the scrape-off layer such as the scrape-off layer width. This rate is estimated based on extrapolation from measurements on present devices. A recent physics-based prediction of the blob detection rate [G. Fuchert et al., Plasma Phys. Controlled Fusion 58, 054006 (2016)] has been compared by means of gyrofluid simulations with varying collisionality and shear layer strength. The prediction shows a robust agreement within a factor of two despite varying generation positions and driving instabilities.
High power two-color orbital angular momentum beam generation using vertical external cavity surface emitting lasers
Authors: Lukowski Michal L. , Hessenius Chris , Meyer Jason T. , Wright Ewan M. , Fallahi Mahmoud
Published: January 2018

We report the design and experimental results for a two-chip T-cavity vertical external cavity surface emitting laser utilized for two-color collinear generation of Hermite-Gaussian and Laguerre-Gaussian (LG) transverse modes. A combination of intracavity mode-control elements and an external astigmatic mode converter was used to achieve high power LG modes. By incorporating intracavity birefringent filters in each arm of the T-cavity, wide wavelength tuning in excess of 12 nm of each mode is demonstrated. Output power exceeding 1.5 W is measured for all the modes.
Numerical study on droplet generation in axisymmetric flow focusing upon actuation
Authors: Mu Kai , Si Ting , Li Erqiang , Xu Ronald X. , Ding Hang
Published: January 2018

In the pure axisymmetric flow focusing (AFF), it is difficult to generate uniform droplets due to the random breakup of bulk flows. Therefore, applying external perturbations is a desirable approach to control the monodispersity of the droplets and makes it possible to produce uniform droplets at relatively high flow rates. In the present study, the effects of different external perturbations (waveform shape, frequency f and amplitude A) on the droplet generation are numerically investigated. When the focused phase is singly actuated, the size of the uniform droplets can be obtained and manipulated by adjusting f and A. In particular, the jet breakup has the same frequency as the external perturbation in the generation of uniform droplets. There exists a cutoff frequency beyond which the perturbation cannot control the jet breakup, even with large A. This is found to be associated with the critical condition for the onset of the Rayleigh-Plateau instability. In addition, the reservoir effect of the cone in the AFF effectively reduces the influence of the perturbation on the liquid supply to the liquid jet, accounting for the presence of jetting at low f and large A. Moreover, we apply the perturbations either singly to the focusing phase or simultaneously to the focused and focusing phases and assess their effects on the jet breakup. Finally, the square waveform perturbations acting on the droplet generation are discussed. The present work provides a guidance of the actuation-aided AFF for practical applications of on-demand droplet generation.
Probing the density of trap states in the middle of the bandgap using ambipolar organic field-effect transistors
Authors: Häusermann Roger , Chauvin Sophie , Facchetti Antonio , Chen Zhihua , Takeya Jun , Batlogg Bertram
Published: January 2018

The number of trap states in the band gap of organic semiconductors directly influences the charge transport as well as the threshold and turn-on voltage. Direct charge transport measurements have been used until now to probe the trap states rather close to the transport level, whereas their number in the middle of the band gap has been elusive. In this study, we use PDIF-CN2, a well known n-type semiconductor, together with vanadium pentoxide electrodes to build ambipolar field-effect transistors. Employing three different methods, we study the density of trap states in the band gap of the semiconductor. These methods give consistent results, and no pool of defect states was found. Additionally, we show first evidence that the number of trap states close to the transport level is correlated with the number of traps in the middle of the band-gap, meaning that a high number of trap states close to the transport level also implies a high number of trap states in the middle of the band gap. This points to a common origin of the trap states over a wide energy range.
Is the subharmonic threshold always lower than the fundamental one in plane Poiseuille flow?
Authors: Kidambi Rangachari , Srinivasan Usha
Published: January 2018

We revisit the secondary instability of a Tollmein-Schlichting wave in plane Poiseuille flow at Re = 5000 and find that the fundamental threshold can be lower than the subharmonic one in the wavenumber space, in contrast to the prevalent view in the literature that only instability of subharmonic modes occurs at very low disturbance amplitudes and fundamental modes need a higher disturbance amplitude to become unstable. This is because of overlooking the even class of fundamental modes, which happen to produce the lower threshold at those wavenumbers.
Nonlinear photocurrent-intensity behavior of amorphous InZnO thin film transistors
Authors: Lu Huiling , Zhou Xiaoliang , Liang Ting , Zhang Letao , Zhang Shengdong
Published: January 2018

The photocurrent (IPH) of amorphous InZnO thin film transistors in the off-state is investigated as a function of incident optical power (P). The results show that IPH exhibits a nonlinear dependence on P. Additionally, the dependence of IPH on P exhibits a strong photon energy (hυ)-dependent feature. When P is relatively low, IPH is shown to be proportional to Pγ, where γ is greater than 1. The γ > 1 behavior may be ascribed to the source-barrier-lowering effect due to the accumulation of photo-induced positive charges at the source side. When P is relatively high, while IPH remains proportional to Pγ under the incident light with hυ larger than the optical bandgap (Eg) of a-IZO, it turns to increase at an exponential rate with P if hυ of the incident light is smaller than the Eg. The exponential increase in IPH is attributed to the source-barrier-thinning effect, which leads to a significantly enhanced tunneling current.
Purcell-enhanced microcavity Raman scattering from pressurized gases
Authors: Gomez Velez Juan , Muller Andreas
Published: January 2018

We have investigated the Purcell enhancement of spontaneous Raman scattering in microcavities with a test gas under pressure. Micromirrors were fabricated on bulk substrates and assembled into sealed microcavity arrays into which gases could be introduced at pressures of up to 35 bar. We focused on the ν1 Q-branch Raman band in carbon dioxide (1388.2 cm−1) and measured the rate of Raman scattered photons as a function of pressure and concentration. The rate was found to increase approximately linearly with pressure with no significant broadening of the lineshape associated with the doubly resonant Purcell-enhanced Raman process. This lack of broadening is a unique feature of the microcavity-based scheme in which mirrors are only separated by a few microns, making pressurization an effective method to lower the limit of detection.
Ultrasonic loading leads to reversible changes in electronic properties of silicon crystals
Authors: Liebendorfer Adam
Published: January 2018

Silicon n + -p-structured crystals show altered shunt resistance, carrier lifetime and ideality factors when interacting with ultrasound frequencies after exposure to reactor neutrons or 60Co gamma radiation.
Direct Vibrational Energy Transfer in Monomeric Water Probed with Ultrafast Two Dimensional Infrared Spectroscopy
Authors: Zhou De-xia , Wei Qian-shun , Bian Hong-tao , Zheng Jun-rong
Published: January 2018

Vibrational relaxation dynamics of monomeric water molecule dissolved in d-chloroform solution were revisited using the two dimensional Infrared (2D IR) spectroscopy. The vibrational lifetime of OH bending in monomeric water shows a bi-exponential decay. The fast component (T1=(1.2±0.1) ps) is caused by the rapid population equilibration between the vibrational modes of the monomeric water molecule. The slow component (T2=(26.4±0.2) ps) is mainly caused by the vibrational population decay of OH bending mode. The reorientation of the OH bending in monomeric water is determined with a time constant of τ=(1.2±0.1) ps which is much faster than the rotational dynamics of water molecules in the bulk solution. Furthermore, we are able to reveal the direct vibrational energy transfer from OH stretching to OH bending in monomeric water dissolved in d-chloroform for the first time. The vibrational coupling and relative orientation of transition dipole moment between OH bending and stretching that effect their intra-molecular vibrational energy transfer rates are discussed in detail.
Modification of Surface Reactivity by CO: Effects on Decomposition and Polymerization of Acetaldehyde on Ru(0001)
Authors: Chen Xiao , Li Fang-liang , Guo Qing , Dai Dong-xu , Yang Xue-ming
Published: January 2018

The adsorption and reaction of acetaldehyde on the clean and CO pre-covered Ru(0001) surfaces have been investigated using temperature programmed desorption method. On the clean Ru(0001) surface, the decomposition of acetaldehyde is the main reaction channel, with little polymerization occurring. However, on the CO pre-covered Ru(0001) surface, the decomposition of acetaldehyde is inhibited considerably with increasing CO coverage. Whereas, the polymerization occurs efficiently, especially at high CO coverage (θCO>0.5 ML), which is strongly CO coverage dependent. Combined with previous studies, the well-ordered hexagonal structure of CO layer formed on the Ru(0001) surface at high CO coverage that matches the configuration of paraldehyde is likely to be the origin of this remarkable phenomenon.
Quasiparticle Band Structures of Defects in Anatase TiO2 Bulk
Authors: Chen Ting-wei , Hao Ya-nan , Ma Yu-chen
Published: January 2018

Quasiparticle band structures of the defective anatase TiO2 bulk with O vacancy, Ti interstitial and H interstitial are investigated by the GW method within many-body Green's function theory. The computed direct band gap of the perfect anatase bulk is 4.3 eV, far larger than the experimental optical absorption edge (3.2 eV). We found that this can be ascribed to the inherent defects in anatase which drag the conduction band (CB) edge down. The occupied band-gap states induced by these defects locate close to the CB edge, excluding the possible contribution of these bulk defects to the deep band-gap state below CB as observed in experiments.
The Role of High Excitations in Constructing Sub-spectroscopic Accuracy Intermolecular Potential of He-HCN: Critically Examined by the High-Resolution Spectra with Resonance States
Authors: Hou Dan , Zhang Xiao-Long , Zhai Yu , Li Hui
Published: January 2018

Interpreting high-resolution rovibrational spectra of weakly bound complexes commonly requires spectroscopic accuracy (<1 cm−1) potential energy surfaces (PES). Constructing high-accuracy ab initio PES relies on the high-level electronic structure approaches and the accurate physical models to represent the potentials. The coupled cluster approaches including single and double excitations with a perturbational estimate of triple excitations (CCSD(T)) have been termed the “gold standard” of electronic structure theory, and widely used in generating intermolecular interaction energies for most van der Waals complexes. However, for HCN-He complex, the observed millimeter-wave spectroscopy with high-excited resonance states has not been assigned and interpreted even on the ab initio PES computed at CCSD(T) level of theory with the complete basis set (CBS) limit. In this work, an effective three-dimensional ab initio PES for HCN-He, which explicitly incorporates dependence on the Q1 (C–H) normal-mode coordinate of the HCN monomer has been calculated at the CCSD(T)/CBS level. The post-CCSD(T) interaction energy has been examined and included in our PES. Analytic two-dimensional PESs are obtained by least-squares fitting vibrationally averaged interaction energies for v1(C–H)=0, and 1 to the Morse/Long-Range potential function form with root-mean-square deviations (RMSD) smaller than 0.011 cm−1. The role and significance of the post-CCSD(T) interaction energy contribution are clearly illustrated by comparison with the predicted rovibrational energy levels. With or without post-CCSD(T) corrections, the value of dissociation limit (D0) is 8.919 or 9.403 cm−1, respectively. The predicted millimeter-wave transitions and intensities from the PES with post-CCSD(T) excitation corrections are in good agreement with the available experimental data with RMS discrepancy of 0.072 cm−1. Moreover, the infrared spectrum for HCN-He complex is predicted for the first time. These results will serve as a good starting point and provide reliable guidance for future infrared studies of HCN doped in (He)n clusters.
The role of Lantana camara in areas of bell miner (Manorina melanophrys) associated dieback and its implications for terrestrial mammal and insectivorous bat populations
Authors: Wright Penny E. , Lambert Kathryn T. A. , McDonald Paul G.
Published: January 2018

Bell miner–associated dieback (BMAD) is a form of canopy decline involving bell miner (Manorina melanophrys) colonies on the eastern coast of Australia. The association can include an understorey of lantana (Lantana camara) preventing eucalypt regeneration. To date, comparatively little is known about the effects of these processes on mammal diversity and abundance. We therefore considered the effects of BMAD and lantana presence on ground mammals and insectivorous bats in four forest sites within New South Wales. These were monitored in association with a restoration project for the treatment of lantana that used glyphosate spraying to kill lantana in half of six 50m×50m quadrats per site (three control and three treated). Passive bioacoustic recorders, infrared cameras and Elliott traps were used to survey understorey fauna over four consecutive nights during each season. We found a greater number of small ground-dwelling and large mammals in control areas with an intact understorey of lantana relative to areas where lantana had been treated. However, insectivorous bats were not influenced by lantana presence. Our results suggest that ground-dwelling mammals benefit from the presence of lantana, as it may provide structural complexity that reduces predation risk and/or provides a food resource.
Molecular characterisation of Interleukin-2 in two Australian marsupials (the tammar wallaby, Notamacropus eugenii, and the Tasmanian devil, Sarcophilus harrisii) facilitates the development of marsupial-specific immunological reagents
Authors: Young Lauren J. , Gurr Jessica , Morris Katrina , Flenady Sabine , Belov Katherine
Published: January 2018

Interleukin-2 (IL-2) is an important regulator of cellular immunity in mammals. For many years, our inability to identify the expression of this cytokine in marsupials hindered our capacity to progress studies in metatherian immunology. Here, we report the use of molecular techniques to characterise the IL-2 gene for the tammar wallaby (Notamacropus eugenii) and the Tasmanian devil (Sarcophilus harrisii), which allowed the prediction of the structure and probable functions of the IL-2 proteins of these species. Deduced marsupial IL-2 proteins show considerable sequence identity to each other and to common brushtail possum (Trichosurus vulpecula) IL-2 (≥65%) but shared only 35% (tammar wallaby) and 32% (Tasmanian devil) identity with human IL-2. This difference means that reagents used to study IL-2 in human and other eutherians are unlikely to cross-react with marsupials. As a key step in furthering our ability to study cellular immune responses in marsupials and, more specifically, the susceptibility of macropodoid marsupials to intracellular pathogens, a polyclonal antibody was designed for the detection and future investigation of tammar wallaby IL-2 protein expression. The molecular data and polyclonal antibody described herein will support our development of gene probes and immunological reagents that will aid studies of infection and disease in marsupials.
Impact of carbohydrate mouth rinsing on time to exhaustion during Ramadan: A randomized controlled trial in Jordanian men
Authors: Bataineh Mo'ath F. , Al‐Nawaiseh Ali M. , Abu Altaieb Mohammad H. , Bellar David M. , Hindawi Omar S. , Judge Lawrence W.
Published: January 2018

Mouth rinsing using a carbohydrate (CHO) solution has been suggested to improve physical performance in fasting participants. This study examined the effects of CHO mouth rinsing during Ramadan fasting on running time to exhaustion and on peak treadmill speed (Vpeak). In a counterbalanced crossover design, 18 sub‐elite male runners (Age: 21 ± 2 years, Weight: 68.1 ± 5.7 kg, VO2max: 55.4 ± 4.8 ml/kg/min) who observed Ramadan completed a familiarization trial and three experimental trials. The three trials included rinsing and expectorating a 25 mL bolus of either a 7.5% sucrose solution (CHO), a flavour and taste matched placebo solution (PLA) for 10 s, or no rinse (CON). The treatments were performed prior to an incremental treadmill test to exhaustion. Three‐day dietary and exercise records were obtained on two occasions and analysed. Anthropometric characteristics were obtained and recorded for all participants. A main effect for mouth rinse on peak velocity (Vpeak) (CHO: 17.6 ± 1.5 km/h; PLA: 17.1 ± 1.4 km/h; CON: 16.7 ± 1.2 km/h; P < .001, ηp2 = 0.49) and time to exhaustion (CHO: 1282.0 ± 121.3 s; PLA: 1258.1 ± 113.4 s; CON: 1228.7 ± 98.5 s; P = .002, ηp2 = 0.41) was detected, with CHO significantly higher than PLA (P < .05) and CON (P < .05). Oxygen consumption, heart rate, respiratory exchange ratio, and rating of perceived exertion were not significantly different between treatments or trials (P > .05). Energy availability from dietary analysis, body weight, and fat‐free mass did not change during the last two weeks of Ramadan (P > .05). This study concludes that carbohydrate mouth rinsing improves running time to exhaustion and peak treadmill speed under Ramadan fasting conditions.
Étale dynamical systems and topological entropy
Authors: Truong Tuyen
Published: January 2018

In this paper, we consider two questions about topological entropy of dynamical systems. We propose to resolve these questions by the same approach of using étale analogs of topological and algebraic dynamical systems.

The first question is to define topological entropy for a topological dynamical system

(
f
,
X
,
Ω
)

(f,X,\Omega )

. The main idea is to make use of, in addition to invariant compact subspaces of

(
X
,
Ω
)

(X,\Omega )

, compactifications of étale covers

π
:
(

f
′

,

X
′

,

Ω
′

)
→
(
f
,
X
,
Ω
)

\pi :(f’,X’,\Omega ’)\rightarrow (f,X,\Omega )

; that is,

π
∘

f
′

=
f
∘
π

\pi \circ f’=f\circ \pi

and the fibers of

π
\pi

are all finite. We prove some basic results and propose a conjecture, whose validity allows us to prove further results.

The second question is to define topological entropy for algebraic dynamical systems, with the requirement that it should be as close to the pullback on cohomology groups as possible. To this end, we develop an étale analog of algebraic dynamical systems.
Detection of antibiotic resistance toxigenic Clostridium difficile in processed retail lettuce
Authors: Han Yi , King Joan , Janes Marlene E
Published: January 2018

Objectives: Clostridium difficile is the major cause of infectious diarrhoea in humans after antimicrobial treatment. Clostridium difficile has been isolated from food animals and meat. The main purpose of this study was to characterize C. difficile isolated from retail lettuce and determine the antibiotic resistance using five common clinical-selected antibiotics (metronidazole, vancomycin, clindamycin, erythromycin, and cefotaxime).

Materials and Methods: Lettuce samples (grown in California, Arkansas, and Louisiana) were purchased from retail stores.

Results: Toxigenic C. difficile was isolated from 13.8 per cent (41/297) of the lettuce samples. Among the toxigenic isolates, only 82.9 per cent (34/41) produced toxin B, 17.1 per cent (7/41) produced both toxin A and toxin B, and two of the Louisiana C. difficile isolates were identified as ribotype 027. Under the treatment of the five antibiotics, the virulence C. difficile isolates were identified as having antibiotic resistance to metronidazole, vancomycin, and erythromycin.

Conclusion: The present study reports the highest prevalence of toxigenic C. difficile in US retail lettuce. The antibiotic resistance to metronidazole, vancomycin, and erythromycin of the isolated C. difficile from retail lettuces could lead to public health concerns.
Preventing Late-Life Depression: Lessons in Intervention Development From Goa, India
Authors: Reynolds Charles F , Dias Amit , Cohen Alex , Morse Jennifer , Anderson Stewart J , Cuijpers Pim , Patel Vikram
Published: January 2018

We describe the development of an intervention strategy for the indicated prevention of depression in older adults living in Goa, India. Of particular novelty, the intervention is deliverable by lay health counselors and is grounded in problem solving therapy for primary care and brief behavioral treatment for insomnia. We have named the intervention “DIL” (the Hindi word for “heart” and an acronym for “depression in late life.”) Additional DIL strategies include psychoeducation in self-management of co-occurring medical disorders such as diabetes mellitus, together with assistance in navigation to needed social and economic resources. We present the results of a preliminary open-trial case series involving 21 participants with subsyndromal symptoms of depression, demonstrating feasibility, acceptability, and benefit to participants. We then present the design of a larger confirmatory trial into which 181 participants have been enrolled. “DIL” is a novel and large depression prevention trial conducted with lay health counselors in a low-resource country. Its results are likely to have implications for depression prevention in older adults in other low- and middle-income countries and to inform contemporary models of the staging of depressive illness in later life.
Mycobacterium chimaera Infection After Aortic Valve Replacement Presenting With Aortic Dissection and Pseudoaneurysm
Authors: O’Neil C R , Taylor G , Smith S , Joffe A M , Antonation K , Shafran S , Kunimoto D
Published: January 2018

We present a case of Mycobacterium chimaera infection presenting with aortic dissection and pseudoaneuysm in a 22-year-old man with a past history of aortic valve replacement. Clinicians should consider M. chimaera infection in those presenting with aortic dissection as a late complication of cardiovascular surgery.
Molecular Identification of Bacteria in Intra-abdominal Abscesses Using Deep Sequencing
Authors: Kozlov Andrew , Bean Lorenzo , Hill Emilie V , Zhao Lisa , Li Eric , Wang Gary P
Published: January 2018

Background

Intra-abdominal abscesses are localized collections of pus, which generally arise from a breach in the normal mucosal defense barrier that allows bacteria from gastrointestinal tract, and less commonly from the gynecologic or urinary tract, to induce inflammation, resulting in an infection. The microbiology of these abscesses is usually polymicrobial, associated with the primary disease process. However, the microbial identity, diversity and richness in intra-abdominal abscesses have not been well characterized, due in part to the difficulty in cultivating commensal organisms using standard culture-based techniques.

Methods

We used culture-independent 16S rRNA Illumina sequencing to characterize bacterial communities in intra-abdominal abscesses collected by percutaneous drainage. A total of 43 abscess samples, including 19 (44.2%) Gram stain and culture-negative specimens, were analyzed and compared with results from conventional microbiologic cultures.

Results

Microbial composition was determined in 8 of 19 culture-negative samples and 18 of 24 culture-positive samples, identifying a total of 221 bacterial taxa or operational taxonomic units (OTUs) and averaging 13.1 OTUs per sample (interquartile range, 8–16.5 OTUs). Microbial richness for monomicrobial and polymicrobial samples was significantly higher than culture-negative samples (17 and 15.2 OTUs vs 8 OTUs, respectively), with a trend toward a higher microbial diversity (Shannon diversity index of 0.87 and 1.18 vs 0.58, respectively).

Conclusions

The bacterial consortia identified by cultures correlated poorly with the microbial composition determined by 16S rRNA sequencing, and in most cases, the cultured isolates were minority constituents of the overall abscess microbiome. Intra-abdominal abscesses were generally polymicrobial with a surprisingly high microbial diversity, but standard culture-based techniques failed to reveal this diversity. These data suggest that molecular-based approaches may be helpful for documenting the presence of bacteria in intra-abdominal abscesses where standard cultures are unrevealing, particularly in the setting of prior antibiotic exposure.
Smart Glasses for Neurosurgical Navigation by Augmented Reality
Authors: Maruyama Keisuke , Watanabe Eiju , Kin Taichi , Saito Kuniaki , Kumakiri Atsushi , Noguchi Akio , Nagane Motoo , Shiokawa Yoshiaki
Published: January 2018

BACKGROUND

Wearable devices with heads-up displays or smart glasses can overlay images onto the sight of the wearer. This technology has never been applied to surgical navigation.

OBJECTIVE

To assess the applicability and accuracy of smart glasses for augmented reality (AR)-based neurosurgical navigation.

METHODS

Smart glasses were applied to AR-based neurosurgical navigation. Three-dimensional computer graphics were created based on preoperative magnetic resonance images and visualized in see-through smart glasses. Optical markers were attached to the smart glasses and the patient's head for accurate navigation. Two motion capture cameras were used for registration and continuous monitoring of the location of the smart glasses in relation to the patient's head. After the accuracy was assessed with a phantom, this technique was applied in 2 patients with brain tumors located in the brain surface.

RESULTS

A stereoscopic view by image overlay through the smart glasses was successful in the phantom and in both patients. Hands-free neuronavigation inside the operative field was available from any angles and distances. The targeting error in the phantom measured in 75 points ranged from 0.2 to 8.1 mm (mean 3.1 ± 1.9 mm, median 2.7 mm). The intraoperative targeting error between the visualized and real locations in the 2 patients (measured in 40 points) ranged from 0.6 to 4.9 mm (mean 2.1 ± 1.1 mm, median 1.8 mm).

CONCLUSION

Smart glasses enabled AR-based neurosurgical navigation in a hands-free fashion. Stereoscopic computer graphics of targeted brain tumors corresponding to the surgical field were clearly visualized during surgery.
Innovative Practice in Advancement of Academic Nurse Educator Careers: Developing Scholarship From Program Grants
Authors: Eddy Linda L. , Hoeksel Renee , Fitzgerald Cindy , Doutrich Dawn
Published: January 2018

We describe an innovative practice in advancing careers of academic nurse educators: demonstrating scholarly productivity from program grants. Scholarly productivity is often narrowly defined, especially in research-intensive institutions. The expectation may be a career trajectory based on the traditional scholarship of discovery. However, nurse educators, especially at the associate and full professor ranks, are often involved in leadership activities that include writing and managing program grants. We encourage the academy to value and support the development of program grants that include significant scholarly components, and we offer exemplars of associate and full professor scholarship derived from these projects.
Evidence establishing a link between prenatal and early-life stress and asthma development
Authors: Rosa Maria José , Lee Alison G. , Wright Rosalind J.
Published: January 2018

Purpose of review

The objective of this review is to provide an update on our evolving understanding of the effects of stress in pregnancy and during early development on the onset of asthma-related phenotypes across childhood, adolescence, and into early adulthood.

Recent findings

Accumulating evidence over the past 2 decades has established that prenatal and early-life psychological stress and stress correlates (e.g., maternal anxiety or depression) increase the risk for childhood respiratory disorders. Recent systematic reviews and meta-analyses including numerous prospective epidemiological and case–control studies substantiate a significant effect of prenatal stress and stress in early childhood on the development of wheeze, asthma, and other atopic-related disorders (eczema and allergic rhinitis), with many studies showing an exposure–response relationship. Offspring of both sexes are susceptible to perinatal stress, but effects differ. The impact of stress on child wheeze/asthma can also be modified by exposure timing. Moreover, coexposure to prenatal stress can enhance the effect of chemical stressors, such as prenatal traffic-related air pollution, on childhood respiratory disease risk. Understanding complex interactions among exposure dose, timing, child sex, and concurrent environmental exposures promises to more fully characterize stress effects and identify susceptible subgroups. Although the link between perinatal stress and childhood asthma-related phenotypes is now well established, pathways by which stress predisposes children to chronic respiratory disorders are not as well delineated. Mechanisms central to the pathophysiology of wheeze/asthma and lung growth and development overlap and involve a cascade of events that include disrupted immune, neuroendocrine, and autonomic function as well as oxidative stress. Altered homeostatic functioning of these integrated systems during development can enhance vulnerability to asthma and altered lung development.

Mechanistic studies that more comprehensively assess biomarkers reflecting alterations across interrelated stress response systems and associated regulatory processes, in both pregnant women and young children, could be highly informative. Leveraging high-throughput systems-wide technologies to include epigenomics (e.g., DNA methylation, microRNAs), transcriptomics, and microbiomics as well as integrated multiomics are needed to advance this field of science. Understanding stress-induced physiological changes occurring during vulnerable life periods that contribute to chronic respiratory disease risk could lead to the development of preventive strategies and novel therapeutic interventions.
Developmental Effects in Masking Release for Speech-in-Speech Perception Due to a Target/Masker Sex Mismatch
Authors: Leibold Lori J. , Buss Emily , Calandruccio Lauren
Published: January 2018

Objectives:

The purpose of this study was to evaluate the extent to which infants, school-age children, and adults benefit from a target/masker sex mismatch in the context of speech detection or recognition in a background of 2 competing talkers. It was hypothesized that the ability to benefit from a target/masker sex mismatch develops between infancy and the early school-age years, as children gain listening experience in multi-talker environments.

Design:

Listeners were infants (7 to 13 months), children (5 to 10 years), and adults (18 to 33 years) with normal hearing. A series of five experiments compared speech detection or recognition in continuous two-talker speech across target/masker conditions that were sex matched or sex mismatched. In experiments 1 and 2, an observer-based, single-interval procedure was used to estimate speech detection thresholds for a spondaic word in a two-talker speech masker. In experiments 3 and 4, speech recognition thresholds were estimated in continuous two-talker speech using a four-alternative, forced-choice procedure. In experiment 5, speech reception thresholds (SRTs) were estimated for adults using the forced-choice recognition procedure after ideal time-frequency segregation processing was applied to the stimuli.

Results:

Speech detection thresholds for adults tested in experiments 1 and 2 were significantly higher when the target word and speech masker were matched in sex than when they were mismatched, but thresholds for infants were similar across sex-matched and sex-mismatched conditions. Results for experiments 3 and 4 showed that school-age children and adults benefit from a target/masker sex mismatch for a forced-choice word recognition task. Children, however, obtained greater benefit than adults in 1 condition, perhaps due to greater susceptibility to masking overall. In experiment 5, adults had substantial threshold reductions and more uniform performance across the 4 conditions evaluated in experiments 3 and 4 after the application of ideal time-frequency segregation to the stimuli.

Conclusions:

The pattern of results observed across experiments suggests that the ability to take advantage of differences in vocal characteristics typically found between speech produced by male and female talkers develops between infancy and the school-age years. Considerable child–adult differences in susceptibility to speech-in-speech masking were observed for school-age children as old as 11 years of age in both sex-matched and sex-mismatched conditions.
Using technology to support clinical care and research in rheumatoid arthritis
Authors: Dixon William G. , Michaud Kaleb
Published: January 2018

Purpose of review

As digital technology becomes more ubiquitous, understanding the current state-of-the-art in digital information use for clinical care and research for patients with rheumatoid arthritis (RA) is timely and relevant.

Recent findings

The opportunities for recording and utilizing high-quality data from rheumatologists are reviewed, as well as opportunities from collecting, integrating and analysing patient-generated data to deliver a step-change in the support and management of RA.

Once greater adoption, standardization and implementation of relevant RA measures are in place within electronic health records (EHRs), patient care will improve and the ability to learn from aggregate experiences increases dramatically. Incorporating passive and patient-reported outcomes into self-management apps and integrating such data into the patient's health record will provide more responsive and better treatment results.
Age of Infection with Kaposi Sarcoma–Associated Herpesvirus and Subsequent Antibody Values Among Children in Uganda
Authors: Nalwoga Angela , Miley Wendell , Labo Nazzarena , Elliott Alison , Cose Stephen , Whitby Denise , Newton Robert
Published: January 2018

We investigated associations between Kaposi sarcoma–associated herpesvirus (KSHV) seroconversion age and KSHV antibody values in Ugandan children. Every annual delay in KSHV seroconversion age was associated with a reduction of 19% (P < 0.0001) in K8.1 and 27% (P < 0.0001) in ORF73 antibody values at 6 years of age. Early infection may be an important risk factor for KSHV pathogenesis and viral shedding in saliva, leading to transmission.
Diabetes medications and cardiovascular disease: at long last progress
Authors: Lupsa Beatrice C. , Inzucchi Silvio E.
Published: January 2018

Purpose of review

Although intensive control of hyperglycemia has been proven to decrease the risk of microvascular complications in type 2 diabetes, it has had little apparent effect on reducing cardiovascular complications – the leading cause of mortality in this disease. We review the cardiovascular effects of various glucose-lowering medications, with a particular focus on the recent studies demonstrating clear benefits from members of several drug categories.

Recent findings

Recently, several randomized controlled studies have revealed significant improvements in cardiovascular outcomes from a thiazolidinedione, two sodium-glucose cotransporter 2 inhibitors and two glucagon-like peptide 1 receptor agonists.

These data suggest that certain glucose lowering agents after metformin should be favored in type 2 diabetes mellitus patients when there is underlying cardiovascular disease.
Button Battery Powered Fidget Spinners
Authors: Khalaf Racha T. , Gurevich Yoseph , Marwan Ahmed I. , Miller Angie L. , Kramer Robert E. , Sahn Benjamin
Published: January 2018

Toys entering the marketplace may have unrecognized hazard risks until data on injury become known. The fidget spinner is a new popular toy mass marketed to children and is primarily sold without warning labels. The US Consumer Product Safety Commission has recently issued a formal statement on potential safety concerns related to ingestion of the toy parts and other hazards. Button batteries within this toy pose the greatest danger to children as ingestion can lead to lethal injury. We report 2 cases of children who swallowed a button battery from a fidget spinner, causing severe esophageal injury. Various aspects of this type of ingestion important for clinicians to be aware of are reviewed.
Pain Intensity and Risk of Bone Fracture in Children With Minor Extremity Injuries
Authors: Zanchi Chiara , Giangreco Manuela , Ronfani Luca , Germani Claudio , Giorgi Rita , Calligaris Lorenzo , Norbedo Stefania , Liccari Giulio , Cozzi Giorgio , Barbi Egidio
Published: January 2018

Objectives

Injuries are one of the most common causes of pediatric emergency department (ED) visit. The aim of this study was to investigate the relationship between the intensity of pain at the ED visit of children presenting with an extremity injury and the risk of fracture.

Methods

We conducted a retrospective study, considering all patients presenting to the ED of a children's hospital in Italy, with an accidental extremity injury, between May and December 2015. We selected all children aged 8 to 17 years who underwent an x-ray. Children with major, multiple, or nonextremity injuries were excluded. Age, sex, spontaneous and palpation pain, local swelling, time between injury, and medical evaluation were recorded. Sensibility and specificity of spontaneous and palpation pain in detecting a fracture were calculated.

Results

We reviewed 994 medical records; of these, 344 (34.6%) reported a fracture. Children's median age was 12 years (interquartile range [IQR], 10–14). Median spontaneous pain at the ED visit was not significantly different between children with and without a fracture: 4.0 (1.0–6.0) and 5 (1.0–6.0), respectively (P = 0.129). Children with mild palpation pain and children without an increase of pain of at least 2 points between spontaneous and palpation pain were fractured in 3.2% and 0.97% of cases, respectively.

Conclusions

In this series, pain intensity in children with a minor extremity injury was not a good marker of fracture. Nevertheless, children with mild palpation pain or with a mild increase of pain between spontaneous and palpation pain had a low risk of fracture.
BackPack
Authors: Wright Lauri , Epps James B.
Published: January 2018

An increasing gap has been seen between the government food assistance programs and those who need help. One program filling the gap is Feeding America's BackPack Program that provides nutritious food to children to eat on the weekends when they may not have access to adequate food. This project evaluated the impact of the BackPack Program on food security, readiness to learn, and behavioral and mental health of a group of children using a mixed methods approach. Results showed improved food security and increased readiness to learn among participants. The BackPack Program may be an effective means for meeting gaps in food assistance for children and their parents.
Differences in the Effect of Plant Sterols on Lipid Metabolism in Men and Women
Authors: San Mauro-Martín Ismael , Blumenfeld-Olivares Javier Andrés , Garicano-Vilar Elena , Cuadrado María Ángeles , Ciudad-Cabañas María José , Collado-Yurrita Luis
Published: January 2018

Plant sterols are recommended to decrease low-density lipoprotein cholesterol (LDL-C). Possible differences between sexes in efficacy were analyzed. In a double-blind crossover clinical trial, 30 women and 24 men were divided into 2 phases of 3 weeks, separated by a 2-week washout period. Subjects ingested 2.23 g/day of sterols in 700-mL milk. Total cholesterol (TC), LDL-C, high-density lipoprotein cholesterol (HDL-C), triglyceride, and non-HDL-C were assessed. There was significant interaction of sex factors×time intervention in TC (F(1.49) = 4.54, η2 = 0.085), LDL-C (F(1.46) = 4.72, η2 = 0.093), HDL-C (F(1.48) = 9.37, η2 = 0.163), and non-HDL-C (F(1.48) = 9.97, η2 = 0.172). Total body fat in the control group and cholesterol reduction were significantly correlated with LDL-C (r = 0.463) and non-HDL-C (r = 0.482) reduction percentage (P < .05). Differences in sex effect were observed.
Body Weight Status, Clinical Factors, and Short-term Outcomes Among Head and Neck Radiation Oncology Patients
Authors: Wallace Whitney C. , Feigenberg Steven J. , Tyer Tiffani N. , Pope Janet F. , Erickson Dawn M. , Hanson Jennifer A.
Published: January 2018

In a retrospective review of treatment records from head and neck radiation oncology patients (N = 145), χ2and logistic regression analyses (P≤ .05) were used to determine differences in short-term outcomes based on weight status and clinical factors. Significant weight loss was higher among obese patients and those patients with tumor stage 2 or greater. Significant weight loss, dehydration, and hospitalizations were higher among patients receiving chemotherapy. Hospitalizations were higher also among patients with multiple comorbidities. The characteristics were associated with short-term outcomes and should be examined when setting priorities for nutrition care of head and neck cancer patients.
Deleting the IF
1
-like
ζ
subunit from
Paracoccus denitrificans
ATP synthase is not sufficient to activate ATP hydrolysis
Authors: Varghese Febin , Blaza James N. , Jones Andrew J. Y. , Jarman Owen D. , Hirst Judy
Published: January 2018

In oxidative phosphorylation, ATP synthases interconvert two forms of free energy: they are driven by the proton-motive force across an energy-transducing membrane to synthesize ATP and displace the ADP/ATP ratio from equilibrium. For thermodynamically efficient energy conversion they must be reversible catalysts. However, in many species ATP synthases are unidirectional catalysts (their rates of ATP hydrolysis are negligible), and in others mechanisms have evolved to regulate or minimize hydrolysis. Unidirectional catalysis by
Paracoccus denitrificans
ATP synthase has been attributed to its unique
ζ
subunit, which is structurally analogous to the mammalian inhibitor protein IF
1
. Here, we used homologous recombination to delete the
ζ
subunit from the
P. denitrificans
genome, and compared ATP synthesis and hydrolysis by the wild-type and knockout enzymes in inverted membrane vesicles and the F
1
-ATPase subcomplex. ATP synthesis was not affected by loss of the
ζ
subunit, and the rate of ATP hydrolysis increased by less than twofold, remaining negligible in comparison with the rates of the
Escherichia coli
and mammalian enzymes. Therefore, deleting the
P. denitrificans ζ
subunit is not sufficient to activate ATP hydrolysis. We close by considering our conclusions in the light of reversible catalysis and regulation in ATP synthase enzymes.
Ebola could be eradicated through voluntary vaccination
Authors: Brettin Andrew , Rossi–Goldthorpe Rosa , Weishaar Kyle , Erovenko Igor V.
Published: January 2018

Ebola virus disease (EVD) is a severe infection with an extremely high fatality rate spread through direct contact with body fluids. A promising Ebola vaccine (rVSV-ZEBOV) may soon become universally available. We constructed a game-theoretic model of Ebola incorporating individual decisions to vaccinate. We found that if a population adopts selfishly optimal vaccination strategies, then the population vaccination coverage falls negligibly short of the herd immunity level. We concluded that eradication of Ebola is feasible if voluntary vaccination programmes are coupled with focused public education efforts. We conducted uncertainty and sensitivity analysis to demonstrate that our findings do not depend on the choice of the epidemiological model parameters.