bluuebunny/crossref_metadata_2025 huggingface dataset:
Attenuation of low-frequency electromagnetic wave in the thin sheath enveloping a high-speed vehicle upon re-entry
Authors: Liu DongLin , Li XiaoPing , Liu YanMing , Xie Kai , Bai BoWen
Published: February 2017

Low-frequency (LF) electromagnetic (EM) waves are suggested as potentially solving “radio blackout” caused by a plasma sheath enveloping a high-speed vehicle on re-entry. However, the traditional plasma absorption theory neglects the fact that the plasma sheath is electrically small compared to LF EM wavelengths. To understand clearly the attenuation of such waves through the plasma sheath, different attenuation mechanisms for the electric field (SE) and magnetic field (SH) were studied using the equivalent circuit approach. Analytical expressions were derived by modeling the plasma sheath as a spherical shell, and numerical simulations were performed to validate the effectiveness of the expressions. SE and SH are calculated for various plasma parameter settings; the EM wave attenuations obtained from plasma absorption theory are used for comparison. Results show that, instead of SE and SH being equal in the plasma absorption theory, SE and SH are no longer the same for electrically small sizes. Whereas |SH| is close to that from plasma absorption theory, |SE| is much higher. Further analysis shows that |SH| is a function of the ratio of electron density (ne) and collision frequency (ve) and increases with increasing ne/ve. Numerical simulations with radio-attenuation-measurement-C-like vehicle's plasma sheath parameters are performed and the results show that the magnetic field attenuation in the front part of the vehicle is much lower than in the rear. So it is suggested to place the magnetic loop antenna in the very front part of the vehicle. Finally, SH at different frequencies are calculated using plasma sheath parameter values simulating the re-entry phase of a radio-attenuation measurement-C vehicle and results show that such a vehicle might overcome radio blackout during the entire re-entry phase if systems operating below 3 MHz and above the L-band are combined with a lower-frequency system working below Earth's ionosphere and a higher-frequency system working above the Earth's ionosphere.
Phonon interference in crystalline and amorphous confined nanoscopic films
Authors: Liang Zhi , Wilson Thomas E. , Keblinski Pawel
Published: February 2017

Using molecular dynamics phonon wave packet simulations, we study phonon transmission across hexagonal (h)-BN and amorphous silica (a-SiO2) nanoscopic thin films sandwiched by two crystalline leads. Due to the phonon interference effect, the frequency-dependent phonon transmission coefficient in the case of the crystalline film (Si|h-BN|Al heterostructure) exhibits a strongly oscillatory behavior. In the case of the amorphous film (Si|a-SiO2|Al and Si|a-SiO2|Si heterostructures), in spite of structural disorder, the phonon transmission coefficient also exhibits oscillatory behavior at low frequencies (up to ∼1.2 THz), with a period of oscillation consistent with the prediction from the two-beam interference equation. Above 1.2 THz, however, the phonon interference effect is greatly weakened by the diffuse scattering of higher-frequency phonons within an a-SiO2 thin film and at the two interfaces confining the a-SiO2 thin film.
The thermodynamic and transport properties of GdCl3 in molten eutectic LiCl-KCl derived from the analysis of cyclic voltammetry signals
Authors: Samin Adib , Wu Evan , Zhang Jinsuo
Published: February 2017

Pyroprocessing technology is a promising tool for recycling nuclear fuel and producing high purity gadolinium for industrial applications. An efficient implementation of pyroprocessing entails a careful characterization of the electrochemical and transport properties of lanthanides in high temperature molten salts. In this work, the cyclic voltammetry signals of Gd in molten LiCl-KCl salt were recorded for a combination of three temperatures (723 K, 773 K, and 823 K) and three concentration levels (3 wt. %, 6 wt. %, and 9 wt. %) including concentration levels higher than previously reported and relevant for a realistic application of pyroprocessing for molten salt recycle, and the concentration effects were investigated. Four scan rates (200 mV/s to 500 mV/s) were used for each condition, and the signals were examined using conventional Cyclic Voltammetry (CV) analysis equations and by utilizing a two-plate Brunauer, Emmett, and Teller (BET) model accounting for mass diffusion, kinetics, adsorption, and the evolution of electrode morphology via a nonlinear least squares procedure for fitting the model to the experimental signals. It was determined that the redox process is quasi-reversible for the scan rates being used. Furthermore, the applicability of the conventional equations for CV analysis was shown to be problematic for the conditions used, and this is thought to be due to the fact that these equations were derived under the assumption of reversible conditions. The model-derived values for diffusivity are consistent with the literature and are shown to decrease with increasing concentration. This may be due to increased interactions at higher concentration levels. It was also shown that the formal redox potential increased with a concentration and was slightly more positive on the covered electrode.
Exploring graphene superlattices: Magneto-optical properties
Authors: Duque C. A. , Hernández-Bertrán M. A. , Morales A. L. , de Dios-Leyva M.
Published: February 2017

We present a detailed study of magnetic subbands, wave functions, and transition strengths for graphene superlattices (SLs) subject to a perpendicular magnetic field. It is shown that, for a weak magnetic field, the flat subbands of a SL exhibiting extra Dirac points are grouped into subsets, each of which consists of a singlet subband and a nearly degenerate doublet subband, and one nearly degenerate triplet subband. It was found that the wave functions corresponding to a singlet or to a doublet are always located around the image in real space of the central or extra Dirac points in k-space. The latter properties were explained by assuming that the electron motion is quasi-classical. Our study revealed that, for an intermediate field, the general characteristics of the wave functions are very similar to those of the pristine graphene, while for weak field, their behavior is drastically different. The latter is characterized by rapid oscillations which were understood using the solutions provided by the formalism of Luttinger-Kohn. The study on transition strengths allows us to obtain, for SLs with extra Dirac points in a weak magnetic field and different polarizations, the conditions under which transitions between multiplets are approximately allowed. It was shown that these conditions correspond to an unusual selection rule that is broken when the magnetic field intensity increases from weak to an intermediate value.
Gyroscopic g factor of rare earth metals
Authors: Ogata Y. , Chudo H. , Ono M. , Harii K. , Matsuo M. , Maekawa S. , Saitoh E.
Published: February 2017

We develop the in situ magnetization measurement apparatus for observing the Barnett effect consisting of a fluxgate sensor, a high speed rotor with frequencies of up to 1.5 kHz, and a magnetic shield at room temperature. The effective magnetic field (Barnett field) in a sample arising from rotation magnetizes the sample and is proportional to the rotational frequency. The gyroscopic g factor, g′, of rare earth metals, in particular, Gd, Tb, and Dy, was estimated to be 2.00 ± 0.08, 1.53 ± 0.17, and 1.15 ± 0.32, respectively, from the slopes of the rotation dependence of the Barnett field. This study provides a technique to determine the g′ factor even in samples where the spectroscopic method may not be available.
An accurate real-time model of maglev planar motor based on compound Simpson numerical integration
Authors: Kou Baoquan , Xing Feng , Zhang Lu , Zhou Yiheng , Liu Jiaqi
Published: February 2017

To realize the high-speed and precise control of the maglev planar motor, a more accurate real-time electromagnetic model, which considers the influence of the coil corners, is proposed in this paper. Three coordinate systems for the stator, mover and corner coil are established. The coil is divided into two segments, the straight coil segment and the corner coil segment, in order to obtain a complete electromagnetic model. When only take the first harmonic of the flux density distribution of a Halbach magnet array into account, the integration method can be carried out towards the two segments according to Lorenz force law. The force and torque analysis formula of the straight coil segment can be derived directly from Newton-Leibniz formula, however, this is not applicable to the corner coil segment. Therefore, Compound Simpson numerical integration method is proposed in this paper to solve the corner segment. With the validation of simulation and experiment, the proposed model has high accuracy and can realize practical application easily.
Identification of candidate genes for resistance to Soybean mosaic virus strain SC3 by using fine mapping and transcriptome analyses
Authors: Li Cui , Adhimoolam Karthikeyan , Yuan Yuan , Yin Jinlong , Ren Rui , Yang Yongqing , Zhi Haijian
Published: February 2017

This study is a continuation of our earlier reports on the identification and mapping of the Soybean mosaic virus (SMV) strain SC3 resistance gene present on chromosome 13 (LG F) of soybean (Glycine max (L.) Merr.). We used a combination of fine mapping and transcriptome sequencing to discover the candidate genes for SMV resistance in Qihuang-1. To fine-map the resistance gene, near-isogenic lines (NILs) from a cross between Qihuang-1 (resistant) and Nannong 1138-2 (susceptible) were genotyped with simple sequence repeats (SSR) and insertion and deletion (indel) markers to identify recombination events. Analysis of plants carrying key recombination events placed the resistance gene to a 180-kb region of the ‘Williams 82’ genome sequence with 17 annotated genes. Transcriptome and quantitative real-time PCR (qRT-PCR) analyses revealed that SMV resistance in Qihuang-1 was probably attributable to the four candidate genes (Glyma13g25920, Glyma13g25950, Glyma13g25970 and Glyma13g26000). The four candidate genes identified in this study can be used in further studies to investigate the role of resistance genes in conferring SC3 resistance in Qihuang-1.
Effects of annealing on Al–Si coating synthesised by mechanical alloying
Authors: Chen Cheng , Lu Congyang , Feng Xiaomei , Shen Yifu
Published: February 2017

An Al–Si composite coating was synthesised on Ti–6Al–4 V alloy substrate by means of mechanical alloying. The as-synthesised coating had a composite structure. The effects of annealing treatment on the microstructure, the mechanical properties and the oxidation resistance of coating were investigated. The increase in annealing temperature was conductive to the formation of multilayered structure of the coating. The formation processes of the layers at different annealing temperatures were discussed. The coating annealed at 800°C had intermetallic layers, which improved the microhardness and wear resistance of the coating. The microhardness of the coating annealed at 800°C reached more than three times of the substrate microhardness. In addition, the coating annealed at 800°C had a thick inner protecting layer, which could retard the inward diffusion of oxygen during oxidation. The annealing of the coating at 800°C could improve the mechanical properties and oxidation resistance of the coating.
Mid-infrared spectroscopic analysis of saccharides in aqueous solutions with sodium chloride
Authors: Kanou Mikihito , Kameoka Takaharu , Suehara Ken-ichiro , Hashimoto Atsushi
Published: February 2017

The infrared spectral characteristics of three different types of disaccharides (trehalose, maltose, and sucrose) and four different types of monosaccharides (glucose, mannose, galactose, and fructose) in aqueous solutions with sodium chloride (NaCl) were determined. The infrared spectra were obtained using the FT-IR/ATR method and the absorption intensities respected the interaction between the saccharide and water with NaCl were determined. This study also focused on not only the glycosidic linkage position and the constituent monosaccharides, but also the concentration of the saccharides and NaCl and found that they have a significant influence on the infrared spectroscopic characterization of the disaccharides in an aqueous solution with NaCl. The absorption intensities representing the interaction between a saccharide and water with NaCl were spectroscopically determined. Additionally, the applications of MIR spectroscopy to obtain information about saccharide–NaCl interactions in foods and biosystems were suggested.
Mitochondrial dysfunction induces dendritic loss via eIF2α phosphorylation
Authors: Tsuyama Taiichi , Tsubouchi Asako , Usui Tadao , Imamura Hiromi , Uemura Tadashi
Published: February 2017

Mitochondria are key contributors to the etiology of diseases associated with neuromuscular defects or neurodegeneration. How changes in cellular metabolism specifically impact neuronal intracellular processes and cause neuropathological events is still unclear. We here dissect the molecular mechanism by which mitochondrial dysfunction induced by Prel aberrant function mediates selective dendritic loss in Drosophila melanogaster class IV dendritic arborization neurons. Using in vivo ATP imaging, we found that neuronal cellular ATP levels during development are not correlated with the progression of dendritic loss. We searched for mitochondrial stress signaling pathways that induce dendritic loss and found that mitochondrial dysfunction is associated with increased eIF2α phosphorylation, which is sufficient to induce dendritic pathology in class IV arborization neurons. We also observed that eIF2α phosphorylation mediates dendritic loss when mitochondrial dysfunction results from other genetic perturbations. Furthermore, mitochondrial dysfunction induces translation repression in class IV neurons in an eIF2α phosphorylation-dependent manner, suggesting that differential translation attenuation among neuron subtypes is a determinant of preferential vulnerability.
Dual function of TGFβ in lens epithelial cell fate: implications for secondary cataract
Authors: Boswell Bruce A. , Korol Anna , West-Mays Judith A. , Musil Linda S.
Published: February 2017

The most common vision-disrupting complication of cataract surgery is posterior capsule opacification (PCO; secondary cataract). PCO is caused by residual lens cells undergoing one of two very different cell fates: either transdifferentiating into myofibroblasts or maturing into lens fiber cells. Although TGFβ has been strongly implicated in lens cell fibrosis, the factors responsible for the latter process have not been identified. We show here for the first time that TGFβ can induce purified primary lens epithelial cells within the same culture to undergo differentiation into either lens fiber cells or myofibroblasts. Marker analysis confirmed that the two cell phenotypes were mutually exclusive. Blocking the p38 kinase pathway, either with direct inhibitors of the p38 MAP kinase or a small-molecule therapeutic that also inhibits the activation of p38, prevented TGFβ from inducing epithelial–myofibroblast transition and cell migration but did not prevent fiber cell differentiation. Rapamycin had the converse effect, linking MTOR signaling to induction of fiber cell differentiation by TGFβ. In addition to providing novel potential therapeutic strategies for PCO, our findings extend the so-called TGFβ paradox, in which TGFβ can induce two disparate cell fates, to a new epithelial disease state.
Tranexamic Acid: The New Gold Standard?
Authors: Adigweme Obinna O. , Lee Gwo-Chin
Published: February 2017

The management of perioperative blood loss is a critical aspect of hip and knee arthroplasty. Several modalities including autologous blood donation, cell saver, fibrin sealants, bipolar sealers have been utilized to varying degrees of success. Tranexamic acid (TXA), an antifibrinolytic that prevents clot degradation, has been shown to be effective in reducing blood loss and transfusions in hip and knee arthroplasty. TXA can be administered in the IV, topical, and oral forms with all proving to be efficacious. There is currently no consensus in regards to dosage and timing although studies have demonstrated a dose-dependent response. Because of the low price of TXA administration, it has been shown to be cost effective in reducing transfusion and overall hospital costs. Although studies have not revealed increased complications related to TXA administration, the current contraindications include allergy/hypersensitivity, history of recent thrombosis, or thromboembolism, and a hypercoagulable state. This chapter will give an overview of the literature regarding TXA in joint replacement surgery and discuss why TXA should be the new gold standard.
Additional Tools to Prevent Blood Loss in Total Joint Arthroplasty
Authors: Hooper Jessica , Schwarzkopf Ran
Published: February 2017

Acute blood loss anemia following total joint arthroplasty procedures puts patients at risk for multiple perioperative complications. Preventing symptomatic anemia in the arthroplasty patient population is specifically important because these patients are often at greater risk for myocardial ischemia due to medical comorbidities, and because it delays progression with physical therapy. In addition to maintaining hemostasis with meticulous surgical technique, several techniques have been developed to help surgeons minimize blood loss. Fibrin sprays, antifibrinolytics such as tranexamic acid, hypotensive anesthesia, bipolar sealers, reinfusion drains, and specific techniques for arthrotomy closure are several strategies that have become part of a multimodal approach to minimize blood loss and reduce transfusion requirement associated with total joint arthroplasty. Currently, published evidence most supports the routine use of tranexamic acid and hypotensive anesthesia in standard, primary hip and knee arthroplasty, but specific adjunctive strategies may be considered when warranted by the patient’s clinical condition or surgical procedure.
Comparison of Effects of Tranexamic Acid and Transcollation on Blood Loss in Total Knee Arthroplasty
Authors: Boddu Chandrakanth , Vomero Bridgit , Cushner Fred D.
Published: February 2017

Background:

Perioperative use of tranexamic acid (TXA) reduces blood loss during a total knee arthroplasty (TKA). Transcollation using Aquamantys is a radiofrequency bipolar hemostatic sealing technology which prevents postoperative hemarthrosis. A comparison between TXA and transcollation using Aquamantys on the effect of perioperative blood loss in TKA has not yet been reported.

Methods:

This is a retrospective cohort study. Two groups of patients underwent unilateral TKAs: TXA group and Aquamantys group. There were 92 patients in the TXA group and 96 patients in the Aquamantys group. The mean drop in hemoglobin levels between the preoperative and postoperative periods in the TXA group and Aquamantys group were compared using unpaired t test. Also, the proportion of cases in the TXA group and Aquamantys group that had a blood hemoglobin drop of≥4 gm/dL was calculated and the odds ratio of such an outcome among the 2 groups was analyzed.

Results:

The mean preoperative hemoglobin levels (gm/dL) in the TXA and Aquamantys groups were comparable. The mean (range) preoperative hemoglobin levels (gm/dL) in the TXA group and Aquamantys group were 13.2 (9.1 to 16.6) and 13.5 (11.3 to 16.6), respectively (P=0.51). The mean (range) postoperative hemoglobin levels (gm/dL) in TXA group and Aquamantys group were 10.9 (8.2 to 13.9) and 10.6 (7.2 to 13.1), respectively (P=0.55). The mean drop of hemoglobin levels (gm/dL) between the preoperative and postoperative period in the TXA group and Aquamantys group were 2.3 and 2.9, respectively (P=0.0016). More importantly, compared with 4 patients in the TXA group, 18 patients in the Aquamantys group had a perioperative hemoglobin drop of>4 gm/dL which is significant (odds ratio, 5.14; 95% confidence interval, 1.66-15.8; z statistic, 2.85; P=0.004).

Conclusions:

Use of TXA during primary unilateral TKA is statistically more effective compared with Transcollation using Aquamantys both in terms of mean drop of hemoglobin perioperatively and also in decreasing the proportion of patients that develop perioperative hemoglobin drop of >4 gm/dL, of which the latter finding is also clinically significant.

Level of Evidence:

Therapeutic Level III—see instructions for authors for a complete description of levels of evidence.
Relationship Between OCT Angiography Temporal Peripapillary Vessel-Density and Octopus Perimeter Paracentral Cluster Mean Defect
Authors: Holló Gábor
Published: February 2017

Purpose of the Study:

The purpose of the study was to investigate the relationship between optical coherence tomography angiography angioflow vessel-density (PAFD) measured in the retinal nerve fiber layer in the temporal peripapillary sector and the average of the spatially corresponding superior and inferior paracentral cluster mean defect values (mean paracentral MD) measured with Octopus perimetry.

Materials and Methods:

Spaerman’s correlation between temporal peripapillary PAFD acquired with the Angiovue OCT and mean paracentral MD measured with the Normal and tendency-oriented perimetry strategy of Octopus G2 perimetry, respectively, was determined on 1 eye of 13 healthy participants, 22 medically controlled ocular hypertensive, and 27 stable early to moderate glaucoma patients. Octopus perimetry was made within 3 months from optical coherence tomography angiography imaging.

Results:

Strong negative relationship was found irrespective to Octopus test strategy between temporal sector peripapillary PAFD and mean paracentral MD for the total population (r-values: −0.5525 and −0.4496, respectively, P≤0.002), the glaucoma group (r-values: −0.4901 and −0.4936, respectively, P<0.01) and the ocular hypertensive group (r-values: −0.4445 and −0.4496, P≤0.0382). For the healthy eyes, and for all groups when correction for the diffuse defect component of global MD was made using the perimeter’s software, no significant relationship was found.

Conclusions:

Strong negative relationship exists between the temporal peripapillary sector PAFD measured with Angiovue OCT angiography in the retinal nerve fiber layer and mean paracentral cluster MD determined with uncorrected Normal and tendency-oriented perimetry strategies of Octopus perimetry. This relationship may be usefully applied in research when eyes with paracentral scotomas are investigated.
Predicting the Magnitude of Functional and Structural Damage in Glaucoma From Monocular Pupillary Light Responses Using Automated Pupillography
Authors: Pradhan Zia S. , Rao Harsha L. , Puttaiah Narendra K. , Kadambi Sujatha V. , Dasari Srilakshmi , Reddy Hemanth B. , Palakurthy Meena , Riyazuddin Mohammed , Rao Dhanaraj A.S.
Published: February 2017

Purpose:

To predict the magnitude of functional damage [mean deviation (MD) on visual field examination] and structural damage [retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thickness on spectral domain optical coherence tomography] in glaucoma from monocular pupillary light response measurements using automated pupillography.

Methods:

In total, 59 subjects (118 eyes) with either a confirmed or suspected diagnosis of glaucoma underwent automated pupillography, along with visual fields and spectral domain optical coherence tomography examinations. Association between pupillary light response measurements of each eye [amplitude of constriction, latency of onset of constriction (L
oc), latency of maximal constriction (L
maxc), velocity of constriction and velocity of redilation] and corresponding MD, average RNFL, and average GCC measurements were evaluated using univariate and multivariate regression analysis after accounting for the multicollinearity. Goodness of fit of the multivariate models was evaluated using coefficient of determination (R
2).

Results:

Multivariate regression models that contained L
oc and L
maxc showed the best association with MD (R
2 of 0.30), average RNFL thickness (R
2=0.18) and average GCC thickness (R
2=0.26). The formula that best predicts the MD could be described as: MD=−14.06−0.15×L
oc+0.06×L
maxc. The formula that best predicts the average RNFL thickness could be described as: Average RNFL thickness=67.18−0.22×L
oc+0.09×L
maxc.

Conclusions:

Glaucomatous damage as estimated by MD, RNFL, and GCC thickness measurements were best predicted by the latency parameters (L
oc and L
maxc) of pupillography. Worsening of glaucomatous damage resulted in a delayed onset of pupillary constriction and a decreased L
maxc.
Relationship Between Anterior Lamina Cribrosa Surface Tilt and Glaucoma Development in Myopic Eyes
Authors: Lee Eun Jung , Han Jong Chul , Kee Changwon
Published: February 2017

Purpose:

To evaluate the anterior lamina cribrosa (LC) surface tilt angle in myopic eyes and associate it with glaucoma development.

Materials and Methods:

In this retrospective study, medical records of myopic patients referred for glaucoma examination from July 1, 2012 to March 30, 2016 were reviewed. Comprehensive ophthalmic examination including spectral-domain optical coherence tomography were performed. We measured the angle of anterior LC surface tilt against Bruch’s membrane opening from optical coherence tomography images at the center of the clinical optic disc margin. In horizontal and vertical sections, the angles were defined as α and β, respectively. Patients were grouped according to the presence of glaucomatous damage and factors including optic nerve head morphologic parameters and LC tilt angles were compared between the 2 groups.

Results:

Among 138 patients originally enrolled, 102 patients were finally analyzed. One eye from 1 patient was randomly chosen. Fifty-five eyes had glaucoma and 47 were normal. The degree of myopia and all optic nerve head morphologic parameters were not significantly different between the 2 groups. However, |α| and |β| were significantly larger in the glaucoma group (all P<0.001), and significances were maintained in multivariate analysis (P<0.001).

Conclusions:

Larger anterior LC surface tilt angles were related to the presence of glaucoma in normal-pressure myopic eyes. Angulation of the LC against Bruch’s membrane opening plane might be associated with increased glaucoma susceptibility in myopic eyes. Further investigations are warranted before clinical utilization of LC tilt as glaucoma susceptibility biomarker.
Retinotopic fMRI Reveals Visual Dysfunction and Functional Reorganization in the Visual Cortex of Mild to Moderate Glaucoma Patients
Authors: Zhou Wei , Muir Eric R. , Nagi Kundandeep S. , Chalfin Steven , Rodriguez Pavel , Duong Timothy Q.
Published: February 2017

Purpose:

To investigate retinotopic functional representation in the visual cortex of mild to moderate primary open-angle glaucoma (POAG) participants and age-matched normal volunteers using high-resolution retinotopic blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI).

Methods:

fMRI was performed on 9 POAG participants (61±11 y old) and 9 age-matched controls (58±5 y old) were studied. A wide-view visual presentation (±55 degrees) was used to evaluate central and peripheral vision. Cortical magnification factors and BOLD% changes as a function of eccentricity. Correlation analysis between BOLD% changes and visual field scores, and between BOLD% changes and retinal nerve fiber layer thicknesses was performed. Comparison of BOLD% changes for individual visual field quadrants between POAG subgroups and normal group was performed.

Results:

BOLD% changes of POAG participants in peripheral visual regions were reduced compared to normals but similar in central visual regions, consistent with the notion of peripheral vision being affected first and more compared to central vision. fMRI retinotopic mapping revealed enlarged representation of the parafovea in the visual cortex of POAG participants compared to normals. Cortical magnification of the central, but not peripheral, visual representation in the visual cortex was larger in POAG participants, suggesting functional remapping. BOLD% changes of individual visual field quadrants were significantly correlated with visual field scores and with retinal nerve fiber layer thickness in the corresponding quadrants.

Conclusions:

These results support the hypothesis that there are functional alteration and remapping in the topographic representation of the visual cortex in POAG participants, and these changes are correlated with disease severity.
Leading in the Healthcare Vortex
Authors: Warshawsky Nora , Andrews Diane , Bacon Cynthia Thornton , Cherry Barbara , Kowalski Karren , Nelson-Brantley Heather , Sherman Rose O.
Published: February 2017

The 2016 International Nursing Administration Research Conference, Leading in a Healthcare Vortex, was held in Orlando, Florida. The program drew 116 attendees with representation from Canada and Brazil. Participants from practice, education, and research discussed leadership in our turbulent healthcare climate, which are highlighted in this column. The conference was dedicated to the memory of Dr Heather S. Laschinger in recognition of her distinguished research legacy of empowering nursing work environments and mentorship of prominent nursing administration researchers.
Enhancing a Culture of Inquiry
Authors: Patterson Amy E. , Mason Tina M. , Duncan Pamela
Published: February 2017

This article describes a Magnet®-designated, national cancer institute comprehensive cancer center’s quest to restructure the organization’s evidence-based practice (EBP)/performance improvement (PI) framework leveraging the role of the clinical nurse specialist (CNS) as a coach to support staff nurses in EBP/PI initiatives. The support of the CNS is essential in developing effective projects, minimizing barriers, and maintaining a level of engagement in the EBP process from problem identification through dissemination and sustainment of practice changes.
Mitochondrial metabolites: undercover signalling molecules
Authors: Frezza Christian
Published: February 2017

Mitochondria are one of most characterized metabolic hubs of the cell. Here, crucial biochemical reactions occur and most of the cellular adenosine triphosphate (ATP) is produced. In addition, mitochondria act as signalling platforms and communicate with the rest of the cell by modulating calcium fluxes, by producing free radicals, and by releasing bioactive proteins. It is emerging that mitochondrial metabolites can also act as second messengers and can elicit profound (epi)genetic changes. This review describes the many signalling functions of mitochondrial metabolites under normal and stress conditions, focusing on metabolites of the tricarboxylic acid cycle. We provide a new framework for understanding the role of mitochondrial metabolism in cellular pathophysiology.
Mitochondrially targeted fluorescent redox sensors
Authors: Yang Kylie , Kolanowski Jacek L. , New Elizabeth J.
Published: February 2017

The balance of oxidants and antioxidants within the cell is crucial for maintaining health, and regulating physiological processes such as signalling. Consequently, imbalances between oxidants and antioxidants are now understood to lead to oxidative stress, a physiological feature that underlies many diseases. These processes have spurred the field of chemical biology to develop a plethora of sensors, both small-molecule and fluorescent protein-based, for the detection of specific oxidizing species and general redox balances within cells. The mitochondrion, in particular, is the site of many vital redox reactions. There is therefore a need to target redox sensors to this particular organelle. It has been well established that targeting mitochondria can be achieved by the use of a lipophilic cation-targeting group, or by utilizing natural peptidic mitochondrial localization sequences. Here, we review how these two approaches have been used by a number of researchers to develop mitochondrially localized fluorescent redox sensors that are already proving useful in providing insights into the roles of reactive oxygen species in the mitochondria.
ClickIn: a flexible protocol for quantifying mitochondrial uptake of nucleobase derivatives
Authors: Hoogewijs Kurt , James Andrew M. , Smith Robin A. J. , Abendroth Frank , Gait Michael J. , Murphy Michael P. , Lightowlers Robert N.
Published: February 2017

There is an increasing interest in targeting molecules to the mitochondrial matrix. Many proteins are naturally imported through the translocase complexes found in the outer and inner mitochondrial membranes. One possible means for importing molecules is therefore to use a mitochondrial pre-protein as a vector and assess what forms of molecules can be attached to the pre-protein as cargo. A major difficulty with this approach is to ensure that any chimaeric molecule does indeed access the mitochondrial matrix and does not merely associate with the mitochondrial membranes. We have recently demonstrated that click chemistry can be used both to demonstrate convincingly mitochondrial import of a peptide–peptide nucleic acid conjugate and also to quantify the mitochondrial uptake for specific synthetic conjugates. We now report an adaptation of the synthesis to facilitate simple quantification of multiple molecules and hence to calculate the efficiency of their mitochondrial import.
Monitoring yeast mitochondria with peroxiredoxin-based redox probes: the influence of oxygen and glucose availability
Authors: Pastor-Flores Daniel , Becker Katja , Dick Tobias P.
Published: February 2017

Mitochondrially generated oxidants are believed to play important roles in both physiology and pathophysiology. Therefore, it is of significant interest to better understand the metabolic conditions leading to enhanced mitochondrial oxidant generation. Here, we investigate the influence of oxygen and glucose availability on the redox state of peroxiredoxin-based redox probes, expressed in the cytosol and mitochondrial matrix of yeast cells. We observe that the redox state of peroxiredoxin probes reflects the balance between dioxygen-dependent peroxide generation and glucose-dependent generation of reducing equivalents. The oxidative pentose phosphate pathway appears to be the dominant source of NADPH in the system under study.
Chromone scaffold–mediated reprogramming of the epithelial–mesenchymal transition prevents fibrosis
Authors: Kim Han-Soo , Kim Jun-Hwan , Yoon Young-Min , Meang Moon Kee , Lee Ji Yong , Lee Tae Hee , Kim Ik-Hwan , Youn Byung-Soo
Published: February 2017

Fibrotic diseases are major causes of morbidity and mortality, and the epithelial–mesenchymal transition (EMT) plays a central role in the development of tissue/organ fibrosis. We discovered that eupatilin, a member of the chromone scaffold (CS)-containing compounds found ubiquitously in the plant kingdom, completely reversed fibrogenesisin vitroand substantially ameliorated bleomycin-induced lung fibrosis (BILF). Furthermore, eupatilin-induced growth arrest and morphological changes in primary fibroblasts derived from a patient with idiopathic pulmonary fibrosis (IPF). To better understand fibrosis, we established a mouse hepatic stellate cell (HSC) line that was robustly differentiated into myofibroblasts upon treatment with TGFβ. HSC-derived fibrogenesis was completely blocked by eupatilin, which caused dramatic morphological changes while inhibiting expression of EMT-related genes. The chemical groups linked to the 2ndcarbon (C2), C3, C6, and C7 on the CS of eupatilin were essential for its anti-fibrogenic effects. Unlike eupatilin, pirfenidone failed to block HSC fibrogenesis and did not affect the morphology of HSCs or lung fibroblasts. Although pirfenidone affected local production of TGFβ, as reflected by a reduction in the TGFβ level in lung lysates of BILF model mice, eupatilin is likely to act via a different therapeutic mechanism. In particular, eupatilin had greater anti-fibrotic capacity and EMT-inhibitory activity and significantly attenuated the phosphorylation of Erk by TGFβ. Based on the interactome,Integrinβ3seems to be a major player in integration of TGFβ signaling into the eupatilin-mediated anti-fibrosis. Our findings suggest that combinatorial use of eupatilin and pirfenidone may augment the therapeutic efficacy of IPF treatment.
Harnessing olfactory bulb oscillations to perform fully brain-based sleep scoring and track sleep/wake transitions across multiple time scales in mice
Authors: Bagur Sophie , Lacroix Marie Masako , de Lavilléon Gaëtan , Lefort Julie M , Geoffroy Hélène , Benchenane Karim
Published: February 2017

It has long been thought that sleep scoring could not be achieved with brain signals alone despite the deep neuromodulatory transformations that accompany sleep state changes. Here we demonstrate using multi-site electrophysiological LFP recordings in freely moving mice that gamma power in the olfactory bulb (OB) allows for clear classification of sleep and wake. Coupled with hippocampal theta activity, it allows the construction of a sleep scoring algorithm that relies on brain activity alone. This method reaches over 90% homology with classical methods based on muscular activity (EMG) and video tracking. Moreover, contrary to EMG, OB gamma power allows correct discrimination between sleep and immobility in ambiguous situations such as fear-related freezing. We use the instantaneous power of hippocampal theta oscillation and OB gamma oscillation to construct a 2D phase-space that is highly robust across mice and days. Dynamic analysis of trajectories within this space yields a novel characterization of sleep/wake and wake/sleep transitions as deeply divergent phenomena. Whereas waking up is a fast and direct transition, falling asleep is best described as stochastic and gradual change. Altogether this methodology opens the avenue for multi-timescale characterization of sleep states with high temporal resolution based on brain signals only.
Cyanophage-encoded lipid-desaturases: oceanic distribution, diversity and function
Authors: Roitman Sheila , Hornung Ellen , Flores-Uribe José , Sharon Itai , Feussner Ivo , Béjà Oded
Published: February 2017

Cyanobacteria are among the most abundant photosynthetic organisms in the oceans; viruses infecting cyanobacteria (cyanophages) can alter cyanobacterial populations, and therefore affect the local food web and global biochemical cycles. These phages carry auxiliary metabolic genes (AMGs), which rewire various metabolic pathways in the infected host cell, resulting in increased phage fitness. Coping with stress resulting from photodamage appears to be a central necessity of cyanophages, yet the overall mechanism is poorly understood. Here we report a novel, widespread cyanophage AMG, encoding a fatty acid desaturase (FAD), found in two genotypes with distinct geographical distribution. FADs are capable of modulating the fluidity of the host’s membrane, a fundamental stress response in living cells. We show that both viral fatty acid desaturases (vFADs) families are Δ9 lipid desaturases, catalyzing the desaturation at carbon 9 in C16 fatty acid chains. In addition, we present the first fatty acid profiling for marine cyanobacteria, which suggests a unique desaturation pathway of medium to long chain fatty acids no longer than C16, in accordance to the vFADs activity. Our findings suggest that cyanophages fiddle with the infected host’s cell, leading to increased photoprotection and potentially enhancing viral-encoded photosynthetic proteins, resulting in a new viral metabolic network.
Assessment of asymmetric cell divisions in the early development ofCaenorhabditis elegans
Authors: Fickentscher Rolf , Weiss Matthias
Published: February 2017

Asymmetric cell divisions are of fundamental importance for developmental processes, e.g. for the generation of founder cells. Prime examples are asymmetric cell divisions in the P lineage during early embryogenesis of the model organismCaenorhabditis elegans. However, due to a lack of quantitative data it has remained unclear how frequent unequal daughter cell sizes emerge in the nematode’s early embryogenesis, and whether these originate from sterical or biochemical cues. Using quantitative light-sheet microscopy, we have found that about 40% of all cell divisions inC. elegansuntil gastrulation generate daughter cells with significantly different volumes. Removing the embryo’s rigid eggshell revealed asymmetric divisions in somatic cells to be primarily induced by steric effects. Division asymmetries in the germline remained unaltered and were correctly reproduced by a model based on a cell-size independent, eccentric displacement of the metaphase plate. Our data suggest asymmetric cell divisions to be essential for establishing important cell-cell interactions that eventually fuel a successful embryogenesis.

Summary statement

About 40% of all cell divisions in earlyC. elegansembryogenesis are found to be asymmetric. A cell-size independent displacement of the mitotic spindle explains division asymmetries in the germline whereas the confining eggshell induces asymmetries of somatic cells.
Multiple-object tracking as a tool for parametrically modulating memory reactivation
Authors: Poppenk J. , Norman K.A.
Published: February 2017

Converging evidence supports the “non-monotonic plasticity” hypothesis that although complete retrieval may strengthen memories, partial retrieval weakens them. Yet, the classic experimental paradigms used to study effects of partial retrieval are not ideally suited to doing so, because they lack the parametric control needed to ensure that the memory is activated to the appropriate degree (i.e., that there is some retrieval, but not enough to cause memory strengthening). Here we present a novel procedure designed to accommodate this need. After participants learned a list of word-scene associates, they completed a cued mental visualization task that was combined with a multiple-object tracking (MOT) procedure, which we selected for its ability to interfere with mental visualization in a parametrically adjustable way (by varying the number of MOT targets). We also used fMRI data to successfully train an “associative recall” classifier for use in this task: this classifier revealed greater memory reactivation during trials in which associative memories were cued while participants tracked one, rather than five MOT targets. However, the classifier was insensitive to task difficulty when recall was not taking place, suggesting it had indeed tracked memory reactivation rather than task difficulty per se. Consistent with the classifier findings, participants’ introspective ratings of visualization vividness were modulated by MOT task difficulty. In addition, we observed reduced classifier output and slowing of responses in a post-reactivation memory test, consistent with the hypothesis that partial reactivation, induced by MOT, weakened memory. These results serve as a "proof of concept” that MOT can be used to parametrically modulate memory retrieval – a property that may prove useful in future investigation of partial retrieval effects, e.g., in closed-loop experiments.
Crystallographic and optical study of PbHfO3 crystals
Authors: Huband S. , Glazer A. M. , Roleder K. , Majchrowski A. , Thomas P. A.
Published: February 2017

The symmetry of the intermediate high-temperature phase of PbHfO3 has been determined unambiguously to be orthorhombic using a combination of high-resolution X-ray diffraction and birefringence imaging microscopy measurements of crystal plates. While lattice parameter measurements as a function of temperature in the intermediate phase are consistent with either orthorhombic or tetragonal symmetry, domain orientations observed in birefringence imaging microscopy measurements utilizing the Metripol system are only consistent with orthorhombic symmetry with the unit cell in the rhombic orientation of the pseudocubic unit cell.
Twin domain imaging in topological insulator Bi2Te3 and Bi2Se3 epitaxial thin films by scanning X-ray nanobeam microscopy and electron backscatter diffraction
Authors: Kriegner Dominik , Harcuba Petr , Veselý Jozef , Lesnik Andreas , Bauer Guenther , Springholz Gunther , Holý Václav
Published: February 2017

The twin distribution in topological insulators Bi2Te3 and Bi2Se3 was imaged by electron backscatter diffraction (EBSD) and scanning X-ray diffraction microscopy (SXRM). The crystal orientation at the surface, determined by EBSD, is correlated with the surface topography, which shows triangular pyramidal features with edges oriented in two different orientations rotated in the surface plane by 60°. The bulk crystal orientation is mapped out using SXRM by measuring the diffracted X-ray intensity of an asymmetric Bragg peak using a nano-focused X-ray beam scanned over the sample. By comparing bulk- and surface-sensitive measurements of the same area, buried twin domains not visible on the surface are identified. The lateral twin domain size is found to increase with the film thickness.
Resistance to change in the case of mergers and acquisitions: part 2
Authors: Appelbaum Steven H. , Karelis Catherine , Le Henaff Anne , McLaughlin Beverly
Published: February 2017

Purpose

Mergers and acquisitions (M&As) are inherent to firms evolving in today’s business world, whether they be corporate giants, SMEs or start-ups. While the ultimate objective of an M&A is to improve the newly constructed firm’s performance, financial and technical impacts are but some of the considerations the organization will need to face. Indeed, employee resistance appears to be a major factor in the overall success of this strategic move. Throughout this three-part paper, the purpose of this paper is to provide a thorough overview of the forces at play in employee resistance to change, its influence on the M&A’s success, and the ways to address such resistance.

Design/methodology/approach

Based on existing empirical studies, industry expert findings and academic reviews, this paper sought to link together the concepts of communication at a time of change, leadership, employee involvement, feeling of adherence to the firm (the four key pillars), and their respective influences in how they may handicap or aid the firm in achieving its M&A objectives.

Findings

Although it may seem like a straightforward concept, resistance to change in the turbulent time that is a merger and acquisition situation is anything but simple. Classic assumptions of resistance being a negative force or participation being a requisite part of overcoming resistance are challenged. At the same time, leadership and employee feeling of adherence to their previous organization play a supporting role when compared to the significant influence of communication pre, during, and after the merger. The ensuing portrait is thus multifaceted and underscores the complexity of handling an M&A at the human resources level.

Research limitations/implications

Whilst the paper allowed to identify and link the different factors at play, a thorough empirical study in order to compare and contrast those factors at an M&A’s different stages (pre-during-post), and thus evaluate their respective importance, would be commendable.

Practical implications

In providing an overview of several aspects at play in employee resistance to change, this paper allows a management practitioner to consolidate their knowledge on the process’ four key pillars.

Social implications

By illustrating not only its – expected – negative outcomes, but by also providing a glimpse at some potential benefits in terms of increased merger performance, this paper gives managers incentives to not always challenge but also embrace their employee’s resistance to change as a healthy part of the firm’s transformation process.

Originality/value

This literature review provides an overview of resistance to change and draws parallels between the concepts explored herein and the M&A situation, which would be useful to the general practitioner undergoing an M&A.