bluuebunny/crossref_metadata_2025 huggingface dataset:
Stress-induced solid-state amorphization of nanocrystalline Ni and NiZr investigated by atomistic simulations
Authors: Meraj Md. , Deng Chuang , Pal Snehanshu
Published: January 2018

In this study, the feasibility of stress induced solid-state amorphization (SSA) of nanocrystalline (NC) Ni and NiZr alloys having ∼10 nm grain size has been investigated under constant tensile load (uniaxial and triaxial) via molecular dynamics simulations. In order to track the structural evaluation in both NC Ni and NiZr alloys during the SSA process, various types of analysis have been used, including simulated X-ray diffraction, centro-symmetry parameter, Voronoi cluster, common neighbor analysis, and radial distribution function. It is found that SSA in both NC Ni and NiZr alloys can only be achieved under triaxial loading conditions, and the hydrostatic tensile stress required for SSA is significantly lower when at. % Zr is increased in the NC NiZr alloy. Specifically, SSA in NC Ni and Ni-5 at. % Zr alloy was observed only when the temperature and hydrostatic tensile stress reached 800 K and 6 GPa, while SSA could occur in NC Ni-10 at. % Zr alloy under just 2 GPa of hydrostatic tensile stress at 300 K.
Ionic solubility and solutal advection governed augmented evaporation kinetics of salt solution pendant droplets
Authors: Jaiswal Vivek , Harikrishnan A. R. , Khurana Gargi , Dhar Purbarun
Published: January 2018

The presence of dispersed inclusions is known to modify the interfacial characteristics in liquids by adsorption–desorption of the ions at interfaces. The present article reports the influencing role of dissolved ions in a polar fluid on its evaporation dynamics. The evaporation dynamics of pendant droplets of aqueous solutions of variant simple salts and concentrations have been experimentally studied. The presence of salts is observed to enhance the evaporation rate (obeying the classical D2 law), and the enhancement has been found to hold a direct proportionality to the concentration of the dissolved salt. Furthermore, it is observed that the degree of enhancement in the evaporation rate is also directly proportional to the solubility of the salt in question. The phenomenon is explained based on the chemical kinetics and thermodynamics of hydration of the ionic species in the polar fluid. The classical evaporation rate constant formulation is found to be inadequate in modeling the enhanced species transport. Additional probing via particle image velocimetry reveals augmented internal circulation within the evaporating salt based drops compared to pure water. Mapping the dynamic surface tension reveals that a salt concentration gradient is generated between the bulk and periphery of the droplet and it could be responsible for the internal advection cells visualized. A thermo-solutal Marangoni and Rayleigh convection based mathematical formulation has been put forward, and it is shown that the enhanced solute-thermal convection could play a major role in enhanced evaporation. The internal circulation mapped from experiments is found to be in good quantitative agreement with the model predictions. Scaling analysis further reveals that the stability of the solutal Marangoni convection surpasses the thermal counterpart with higher salt concentration and solubility. The present article sheds insight into the possible domineering role of conjugate thermohydraulic and mass transport phenomena on the evaporation kinetics aqueous droplets with ionic inclusions.
Dust acoustic cnoidal waves in a polytropic complex plasma
Authors: El-Labany S. K. , El-Taibany W. F. , Abdelghany A. M.
Published: January 2018

The nonlinear characteristics of dust acoustic (DA) waves in an unmagnetized collisionless complex plasma containing adiabatic electrons and ions and negatively charged dust grains (including the effects of modified polarization force) are investigated. Employing the reductive perturbation technique, a Korteweg–de Vries–Burgers (KdVB) equation is derived. The analytical solution for the KdVB equation is discussed. Also, the bifurcation and phase portrait analyses are presented to recognize different types of possible solutions. The dependence of the properties of nonlinear DA waves on the system parameters is investigated. It has been shown that an increase in the value of the modified polarization parameter leads to a fast decay and diminishes the oscillation amplitude of the DA damped cnoidal wave. The relevance of our findings and their possible applications to laboratory and space plasma situations is discussed.
Simple and high-speed polarization-based QKD
Authors: Grünenfelder Fadri , Boaron Alberto , Rusca Davide , Martin Anthony , Zbinden Hugo
Published: January 2018

We present a simplified BB84 protocol with only three quantum states and one decoy-state level. We implement this scheme using the polarization degree of freedom at telecom wavelength. Only one pulsed laser is used in order to reduce possible side-channel attacks. The repetition rate of 625 MHz and the achieved secret bit rate of 23 bps over 200 km of standard fiber are the actual state of the art.
Whispering gallery mode coulometry of the nanoparticle-microcavity interaction in aqueous solution
Authors: Lopez Jehovani R. , Treasurer Eshan , Snyder Kaitlynn M. , Keng David , Arnold Stephen
Published: January 2018

Charge influences the binding of virus and other nano-particles to microcavity bio-sensors, although surprisingly there have been no reports of the determination of either cavity charge density σw or nanoparticle charge qp using these sensors. In this letter, we experimentally demonstrate an approach for the determination of both. We use an opto-mechanical Whispering Gallery Mode (WGM) Carousel trap to extract the electrostatic interaction energy versus separation s between the cavity surface and a nanoparticle from WGM frequency fluctuations induced by the orbiting particle. Next, we fit this interaction energy to linearized wall-colloid theory (Debye-Hückel theory) for a particle whose charge is known and determine σw. With this microcavity charge density in hand, a larger particle having unknown charge and orbiting the same microcavity has its charge measured from its associated electrostatic interaction energy. This charge is found to be smaller by 10% when compared to results from independent zeta potential measurements and outside of one standard deviation. However, non-linear Gouy-Chapman theory when applied to our measured data arrives at a charge that overlaps zeta potential measurements. Our method is non-destructive, enabling the same particle to be passed on for further characterization.
Giant magneto-spin-Seebeck effect and magnon transfer torques in insulating spin valves
Authors: Cheng Yihong , Chen Kai , Zhang Shufeng
Published: January 2018

We theoretically study magnon transport in an insulating spin valve (ISV) made of an antiferromagnetic insulator sandwiched between two ferromagnetic insulator (FI) layers. In the conventional metal-based spin valve, the electron spins propagate between two metallic ferromagnetic layers, giving rise to giant magnetoresistance and spin transfer torque. Here, the incoherent magnons in the ISV serve as angular momentum carriers and are responsible for the angular momentum transport between two FI layers across the antiferromagnetic spacer. We predict two transport phenomena in the presence of the temperature gradient: a giant magneto-spin-Seebeck effect in which the output voltage signal is controlled by the relative orientation of the two FI layers and magnon transfer torque that can be used for switching the magnetization of the FI layers with a temperature gradient of the order of 0.1 Kelvin per nanometer.
High performance NO2 sensor using MoS2 nanowires network
Authors: Kumar Rahul , Goel Neeraj , Kumar Mahesh
Published: January 2018

We report on a high-performance NO2 sensor based on a one dimensional MoS2 nanowire (NW) network. The MoS2 NW network was synthesized using chemical transport reaction through controlled turbulent vapor flow. The crystal structure and surface morphology of MoS2 NWs were confirmed by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Further, the sensing behavior of the nanowires was investigated at different temperatures for various concentrations of NO2 and the sensor exhibited about 2-fold enhanced sensitivity with a low detection limit of 4.6 ppb for NO2 at 60 °C compared to sensitivity at room temperature. Moreover, it showed a fast response (16 s) with complete recovery (172 s) at 60 °C, while sensitivity of the device was decreased at 120 °C. The efficient sensing with reliable selectivity toward NO2 of the nanowires is attributed to a combination of abundant active edge sites along with a large surface area and tuning of the potential barrier at the intersections of nanowires during adsorption/desorption of gas molecules.
Isolation and purification treatments change the metal-binding properties of humic acids: effect of HF/HCl treatment
Authors: Botero Wander G. , Pineau Michael , Janot Noémie , Domingos Rute F. , Mariano José , Rocha Luciana S. , Groenenberg Jan E. , Benedetti Marc F. , Pinheiro José P.
Published: January 2018

Environmental contextStudying the mechanism of binding between metals and natural organic matter is fundamental to understanding the transport and availability of these contaminants in the environment. The influence of sample treatment on the purification of organic matter showed significant differences in the interaction with metals. The results will contribute to improved modelling of metal binding to organic matter in soils, thereby providing a basis for a more realistic risk assessment.
AbstractWe studied the changes in metal binding characteristics of extracted humic acids induced by HF/HCl treatment followed by dialysis, i.e. the last step of the International Humic Substances Society (IHSS) extraction protocol. We performed metal binding experiments with both the alkaline-extracted material (AE) and the fully purified (FP) humic acid using the electrochemical stripping technique (AGNES) and modelled the results using the NICA-Donnan model. The results showed an increase of free Zn, Cd and Pb concentrations of ~1 order of magnitude for the AE compared with the FP. These differences may be mostly explained by the different carbon content (51.3 % FP and 36.5 % AE) associated with an AE/FP carboxyl ratio of 0.5. Simulations using the NICA-Donnan model showed that halving the amount of carboxylic groups (Qmax,1) for the FP reduced this difference to 0.25 log units for Cd and Zn and to 0.15 log unit for Pb. There is a clear need for further research on the differences between purified v. less-disturbed natural organic material, which will contribute to improved modelling of metal binding to organic matter in soils, hence providing a basis for a more realistic risk assessment.
Impacts of elevated pCO2 on trace gas emissions in two microalgae: Phaeocystis globosa and Nitzschia closterium
Authors: Li Pei-Feng , Yang Gui-Peng , Zhang Jing , Levasseur Maurice , Liu Chun-Ying , Sun Jing , Yang Wei
Published: January 2018

Environmental contextOcean acidification can affect marine microalgae, which can produce climate-active trace gases such as dimethylsulfide and various halocarbons. We conducted monoculture experiments simulating future ocean acidification, and showed that trace gas emissions are affected by elevated pCO2 to different degrees. The responses of trace gases to elevated pCO2 are compound- and species-specific.
AbstractThe potential impacts of seawater acidification on the concentrations of dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP), dissolved acrylic acid (AAd) and various volatile halocarbons, including CH3Cl, CHBr3, CH2Br2, CHBr2Cl, CHBrCl2 and CH3I, were examined during a laboratory CO2 perturbation experiment for the microalgae Phaeocystis globosa and Nitzschia closterium. The microalgae were exposed to ambient CO2 conditions (390–540 µatm; 1 µatm = 0.1 Pa) and to projected concentrations for the end of the century (760–1000 µatm, high carbon (HC)). The growth rate of the two species remained unaffected by elevated CO2. Results showed a 48 and 37 % decline in the DMS concentration normalised to cell density in P. globosa and N. closterium cultures in the HC treatment compared with the ambient treatment. No significant difference was observed for DMSPp and DMSPd in the two microalgae cultures between the two CO2 levels. The mean AAd concentrations in the P. globosa culture showed a 28 % decline in the HC treatment. By contrast, the cell-normalised concentrations of AAd in the HC treatment were 45 % lower than in the ambient treatment in N. closterium cultures. No CO2-induced effects were observed for CH3Cl, CHBr3, CHBr2Cl, CHBrCl2 and CH3I, but cell-normalised concentrations of CH2Br2 in N. closterium cultures showed a 32 % decline in the HC treatment relative to the ambient level. These results show that the metabolism processes responsible for the production of climate-active gases in phytoplankton may be affected by high CO2 levels. There may be a potential delay in the responses of trace gas emissions to elevated pCO2.
DJ-1 deficiency impairs synaptic vesicle endocytosis and reavailability at nerve terminals
Authors: Kyung Jae Won , Kim Jin-Mo , Lee Wongyoung , Ha Tae-Young , Cha Seon-Heui , Chung Kyung-Hwun , Choi Dong-Joo , Jou Ilo , Song Woo Keun , Joe Eun-Hye , Kim Sung Hyun , Park Sang Myun
Published: January 2018

Significance

Synaptic dysfunction is implicated as a major causative factor in neurodegenerative diseases. We focused on the role of DJ-1, a genetic factor for early-onset autosomal recessive Parkinson’s disease, in synaptic vesicle endocytosis. DJ-1 was localized at nerve terminals. In the absence of DJ-1, synaptic vesicle endocytosis and reavailability were severely impaired with no alteration of the structural characteristics of nerve terminals, implying an important role in synaptic vesicle recycling. Intriguingly reexpression of several familial mutants (M26I, E64D, and L166P) of DJ-1 identified in Parkinson’s disease failed to restore synaptic vesicle recycling in DJ-1 KO neurons. Our data collectively indicate that DJ-1 participates in synaptic vesicle endocytosis, and pathogenic mutants of DJ-1 are potentially linked to the synaptic retrieval pathway.
Arabidopsis
mRNA decay landscape arises from specialized RNA decay substrates, decapping-mediated feedback, and redundancy
Authors: Sorenson Reed S. , Deshotel Malia J. , Johnson Katrina , Adler Frederick R. , Sieburth Leslie E.
Published: January 2018

The decay of mRNA plays a vital role in modulating mRNA abundance, which, in turn, influences cellular and organismal processes. In plants and metazoans, three distinct pathways carry out the decay of most cytoplasmic mRNAs: The mRNA decapping complex, which requires the scaffold protein VARICOSE (VCS), removes a protective 5′ cap, allowing for 5′ to 3′ decay via EXORIBONUCLEASE4 (XRN4, XRN1 in metazoans and yeast), and both the exosome and SUPPRESSOR OF VCS (SOV)/DIS3L2 degrade RNAs in the 3′ to 5′ direction. However, the unique biological contributions of these three pathways, and whether they degrade specialized sets of transcripts, are unknown. In
Arabidopsis
, the participation of SOV in RNA homeostasis is also unclear, because
Arabidopsis sov
mutants have a normal phenotype. We carried out mRNA decay analyses in wild-type,
sov
,
vcs
, and
vcs sov
seedlings, and used a mathematical modeling approach to determine decay rates and quantify gene-specific contributions of VCS and SOV to decay. This analysis revealed that VCS (decapping) contributes to decay of 68% of the transcriptome, and, while it initiates degradation of mRNAs with a wide range of decay rates, it especially contributes to decay of short-lived RNAs. Only a few RNAs were clear SOV substrates in that they decayed more slowly in
sov
mutants. However, 4,506 RNAs showed VCS-dependent feedback in
sov
that modulated decay rates, and, by inference, transcription, to maintain RNA abundances, suggesting that these RNAs might also be SOV substrates. This feedback was shown to be independent of siRNA activity.
Light-enabled reversible self-assembly and tunable optical properties of stable hairy nanoparticles
Authors: Chen Yihuang , Wang Zewei , He Yanjie , Yoon Young Jun , Jung Jaehan , Zhang Guangzhao , Lin Zhiqun
Published: January 2018

Significance

This work reports a versatile and robust strategy for creating monodisperse plasmonic nanoparticles (NPs) intimately and permanently capped with photoresponsive polymers via capitalizing on amphiphilic star-like diblock copolymer nanoreactors. The reversibly assembled nanostructures comprising photoresponsive NPs may exhibit a broad range of new attributes, functions, and applications as a direct consequence of size-dependent physical property from individual NP and the collective property originated from the NP interaction due to their close proximity within nanostructure.
Endocrine regulation of airway clearance inDrosophila
Authors: Kim Do-Hyoung , Kim Young-Joon , Adams Michael E.
Published: January 2018

Significance

The branched epithelial structure of the respiratory system, which is highly conserved in the animal kingdom, develops under liquid-filled conditions. In mammals at birth and insects at ecdysis, such respiratory networks undergo air-filling. We found that the neuropeptide Kinin promotes air-filling in the fruit fly respiratory system just prior to ecdysis by mobilizing calcium in tracheal epithelial pickpocket cells, which express homologs of mammalian epithelial Na+channels.
Mechanism of inhibition of retromer transport by the bacterial effector RidL
Authors: Yao Jialin , Yang Fan , Sun Xiaodong , Wang Shen , Gan Ninghai , Liu Qi , Liu Dingdong , Zhang Xia , Niu Dawen , Wei Yuquan , Ma Cong , Luo Zhao-Qing , Sun Qingxiang , Jia Da
Published: January 2018

Retrograde vesicle trafficking pathways are responsible for returning membrane-associated components from endosomes to the Golgi apparatus and the endoplasmic reticulum (ER), and they are critical for maintaining organelle identity, lipid homeostasis, and many other cellular functions. The retrograde transport pathway has emerged as an important target for intravacuolar bacterial pathogens. The opportunistic pathogen
Legionella pneumophila
exploits both the secretory and recycling branches of the vesicle transport pathway for intracellular bacterial proliferation. Its Dot/Icm effector RidL inhibits the activity of the retromer by directly engaging retromer components. However, the mechanism underlying such inhibition remains unknown. Here we present the crystal structure of RidL in complex with VPS29, a subunit of the retromer. Our results demonstrate that RidL binds to a highly conserved hydrophobic pocket of VPS29. This interaction is critical for endosomal recruitment of RidL and for its inhibitory effects. RidL inhibits retromer activity by direct competition, in which it occupies the VPS29-binding site of the essential retromer regulator TBC1d5. The mechanism of retromer inhibition by RidL reveals a hotspot on VPS29 critical for recognition by its regulators that is also exploited by pathogens, and provides a structural basis for the development of small molecule inhibitors against the retromer.
Multidimensional photon correlation spectroscopy of cavity polaritons
Authors: Dorfman Konstantin E. , Mukamel Shaul
Published: January 2018

Significance

We propose a spectroscopic technique that can track the time-dependent state of a dressed molecule in an optical cavity (polariton) by measuring coincidence of two emitted photons. The proposed technique offers an independent control of the spectral and temporal resolution; single-photon detection allows for low-intensity measurements, which do not disturb the state of the cavity field, and time-dependent atom/cavity coupling provides a control tool. Tracking the evolution of the polariton states with time-dependent atom/cavity coupling should be of interest in photochemistry and photobiology and could improve fundamental understanding of many physical processes in strongly coupled atom/radiation states. Possible applications include chemical sensors and quantum information processing.
Family with sequence similarity 13, member A modulates adipocyte insulin signaling and preserves systemic metabolic homeostasis
Authors: Wardhana Donytra Arby , Ikeda Koji , Barinda Agian Jeffilano , Nugroho Dhite Bayu , Qurania Kikid Rucira , Yagi Keiko , Miyata Keishi , Oike Yuichi , Hirata Ken-ichi , Emoto Noriaki
Published: January 2018

Significance

Adipose tissue dysfunction such as impaired insulin action in adipocytes is causally implicated in obesity-related metabolic disorders. However, molecular mechanisms underlying obesity-related adipocyte insulin resistance remain unclear. Here we identify a mechanism in the regulation of adipocyte insulin signaling by Fam13a, which is impaired in obesity. We revealed that Fam13a protects IRS1 from proteasomal degradation by recruiting PP2A and consequently accentuates adipocyte insulin signal cascade. We further demonstrated that genetic loss of Fam13a exacerbated obesity-related metabolic disorders, while targeted activation of Fam13a in adipocytes improved it by altering adipose tissue insulin sensitivity. Our data unveiled a previously unknown mechanism underlying obesity-related adipocyte insulin resistance through Fam13a, highlighting Fam13a as a vital player in the pathogenesis of obesity-related metabolic disorders.
Platelets release pathogenic serotonin and return to circulation after immune complex-mediated sequestration
Authors: Cloutier Nathalie , Allaeys Isabelle , Marcoux Genevieve , Machlus Kellie R. , Mailhot Benoit , Zufferey Anne , Levesque Tania , Becker Yann , Tessandier Nicolas , Melki Imene , Zhi Huiying , Poirier Guy , Rondina Matthew T. , Italiano Joseph E. , Flamand Louis , McKenzie Steven E. , Cote Francine , Nieswandt Bernhard , Khan Waliul I. , Flick Matthew J. , Newman Peter J. , Lacroix Steve , Fortin Paul R. , Boilard Eric
Published: January 2018

Significance

Immune complexes (ICs) form when antibodies encounter their antigens. ICs are present in blood in multiple pathological conditions. Given the abundance of platelets in blood and that they express a receptor for ICs, called Fcγ receptor IIA (FcγRIIA), we examined the impact of ICs in blood in a mouse model. We found that circulating ICs induced systemic shock, characterized by loss of consciousness, by activating platelet FcγRIIA. Shock was mediated by the liberation of serotonin, a molecule better known for its role in the brain, from platelet granules. During shock, platelets were sequestered in the lungs and brain and returned to the blood circulation after their degranulation. Platelets are thus crucial in response to ICs.
Effect of a combination of inulin and polyphenol-containing adzuki bean extract on intestinal fermentation in vitro and in vivo
Authors: Nagata Ryuji , Echizen Mao , Yamaguchi Yukari , Han Kyu-Ho , Shimada Kenichiro , Ohba Kiyoshi , Kitano-Okada Tomoko , Nagura Taizo , Uchino Hirokatsu , Fukushima Michihiro
Published: January 2018

The effect of a combination of inulin (INU) and polyphenol-containing adzuki bean extract (AE) on intestinal fermentation was examined in vitro using fermenters for 48 h and in vivo using rats for 28 d. The total short-chain fatty acid concentrations in the fermenters were decreased by a combination of INU and AE, but the concentration in the INU + AE group was higher than the cellulose (CEL) and CEL + AE groups. The cecal propionate concentration was increased by a combination of INU and AE compared with their single supplement. The ammonia-nitrogen concentration in the fermenters and rat cecum was decreased by INU and AE. Cecal mucin levels were increased by INU and AE respectively. Therefore, our observations suggested that the combination of INU and AE might be a material of functional food that includes several healthy effects through intestinal fermentation.
Stac3 enhances expression of human CaV1.1 in Xenopus oocytes and reveals gating pore currents in HypoPP mutant channels
Authors: Wu Fenfen , Quinonez Marbella , DiFranco Marino , Cannon Stephen C.
Published: January 2018

Mutations of CaV1.1, the pore-forming subunit of the L-type Ca2+ channel in skeletal muscle, are an established cause of hypokalemic periodic paralysis (HypoPP). However, functional assessment of HypoPP mutant channels has been hampered by difficulties in achieving sufficient plasma membrane expression in cells that are not of muscle origin. In this study, we show that coexpression of Stac3 dramatically increases the expression of human CaV1.1 (plus α2-δ1b and β1a subunits) at the plasma membrane of Xenopus laevis oocytes. In voltage-clamp studies with the cut-open oocyte clamp, we observe ionic currents on the order of 1 μA and gating charge displacements of ∼0.5–1 nC. Importantly, this high expression level is sufficient to ascertain whether HypoPP mutant channels are leaky because of missense mutations at arginine residues in S4 segments of the voltage sensor domains. We show that R528H and R528G in S4 of domain II both support gating pore currents, but unlike other R/H HypoPP mutations, R528H does not conduct protons. Stac3-enhanced membrane expression of CaV1.1 in oocytes increases the throughput for functional studies of disease-associated mutations and is a new platform for investigating the voltage-dependent properties of CaV1.1 without the complexity of the transverse tubule network in skeletal muscle.
Closed-form internal impedance model and characterization of mixed carbon nanotube bundles for three-dimensional integrated circuits*
Authors: Lu Qijun , Zhu Zhangming , Yang Yintang , Ding Ruixue , Li Yuejin
Published: January 2018

Based on the complex effective conductivity method, a closed-form expression for the internal impedance of mixed carbon nanotube (CNT) bundles, in which the number of CNTs for a given diameter follows a Gaussian distribution, is proposed in this paper. It can appropriately capture the skin effect as well as the temperature effect of mixed CNT bundles. The results of the closed-form expression and the numerical calculation are compared with various mean diameters, standard deviations, and temperatures. It is shown that the proposed model has very high accuracy in the whole frequency range considered, with maximum errors of 1% and 2.3% for the resistance and the internal inductance, respectively. Moreover, by using the proposed model, the high-frequency electrical characteristics of mixed CNT bundles are deeply analyzed to provide helpful design guidelines for their application in future high-performance three-dimensional integrated circuits.
The Ihara zeta function for infinite graphs
Authors: Lenz Daniel , Pogorzelski Felix , Schmidt Marcel
Published: January 2018

We put forward the concept of measure graphs. These are (possibly uncountable) graphs equipped with an action of a groupoid and a measure invariant under this action. Examples include finite graphs, periodic graphs, graphings, and percolation graphs. Making use of Connes’s noncommutative integration theory, we construct a zeta function and present a determinant formula for it. We further introduce a notion of weak convergence of measure graphs and show that our construction is compatible with it. The approximation of the Ihara zeta function via the normalized version on finite graphs in the sense of Benjamini and Schramm follows as a special case. Our framework not only unifies corresponding earlier results occurring in the literature. It likewise provides extensions to rich new classes of objects such as percolation graphs.
The ascending central series of nilpotent Lie algebras with complex structure
Authors: Latorre Adela , Ugarte Luis , Villacampa Raquel
Published: January 2018

We obtain several restrictions on the terms of the ascending central series of a nilpotent Lie algebra

g

\mathfrak {g}

under the presence of a complex structure

J
J

. In particular, we find a bound for the dimension of the center of

g

\mathfrak {g}

when it does not contain any non-trivial

J
J

-invariant ideal. Thanks to these results, we provide a structural theorem describing the ascending central series of 8-dimensional nilpotent Lie algebras

g

\mathfrak {g}

admitting this particular type of complex structure

J
J

. Since our method is constructive, it allows us to describe the complex structure equations that parametrize all such pairs

(

g

,
J
)

(\mathfrak {g}, J)

.
Clinical Characterization of Invasive Disease Caused by Haemophilus influenzae Serotype b in a High Vaccination Coverage Setting
Authors: Monge Susana , Mollema Liesbeth , de Melker Hester , Sanders Elisabeth , van der Ende Arie , Knol Mirjam
Published: January 2018

This national study characterized invasive Haemophilus influenzae serotype b infections. Vaccinated (n = 41) and nonvaccinated (n = 10) cases were similar regarding presentation as meningitis (68.8% vs 90.0%; P = .25), predisposing factors (29.3% vs 20.0%; P = .76), admission to intensive care unit or death (22.0% vs 10.0%; P = 1.00), or sequelae (21.6% vs 10.0%; P = .81). Haemophilus influenzae serotype b occurred in vaccinated, healthy children with comparable disease course.
Advancing Tobacco Product Warning Labels Research Methods and Theory: A Summary of a Grantee Meeting Held by the US National Cancer Institute
Authors: Thrasher James F , Brewer Noel T , Niederdeppe Jeff , Peters Ellen , Strasser Andrew A , Grana Rachel , Kaufman Annette R
Published: January 2018

Background

The World Health Organization’s Framework Convention on Tobacco Control recommends prominent pictorial health warnings on tobacco products. To advance research methods, theory and understanding of how tobacco product warning labels (TPWLs) work, the US National Cancer Institute convened a grantee meeting. Our article describes the key insights that emerged from the meeting, situated within the context of the scientific literature.

Results & Recommendations

First, presentations confirmed that large, pictorial TPWLs motivate people to try to quit and encourage smoking cessation. Second, pictorial TPWLs increase attention, knowledge, negative affect, and thinking about the warning. Third, TPWL studies have primarily used brief-exposure laboratory studies and observational studies of sustained exposure through national policy implementation, with a few randomized trials involving several weeks of exposure—with generally consistent results found across study designs. Fourth, novel assessment methods include brain imaging, eye tracking and “best-worst” discrete choice experiments. To make TPWL even more effective, research is needed to confirm the mechanisms of their influence, their impact across vulnerable populations, and their effect on social media posts about tobacco products. Research is also needed on the effect of trial design choices, the predictive validity of new measurement approaches, and warning labels for non-cigarette tobacco products.

Implications

To improve scientific understanding of TPWL effects, this grantee meeting summary describes emerging research methods, theory and study results. Directions for future research include examination of the mechanisms of how warning labels work across diverse tobacco products and across different populations and contexts.
Whose Paper Is It Anyway? Authorship Criteria According to Established Scholars in Health Professions Education
Authors: Uijtdehaage Sebastian , Mavis Brian , Durning Steven J.
Published: January 2018

Purpose

The health professions education (HPE) community is a crossroad of scholars from various disciplines with potentially conflicting views on who qualifies as author. Established HPE scholars are expected to model ethical research conduct, but no research has investigated the extent to which authorship criteria are understood and applied by leaders in the field. This study investigated what leading scholars consider appropriate criteria for authorship and how often these criteria are ignored.

Method

Directors of research and editors of HPE journals completed an anonymous survey between September 2015 and August 2016 with questions about authorship practices they experienced and recommended, common authorship criteria, and how often they had encountered unethical authorship decisions.

Results

Out of 82 invited scholars, 46 participated in the survey (response rate = 56.0%). They reported a stark contrast between current and recommended authorship practices. Twenty-two (51.2%) had experienced unethical pressure regarding authorship order, 15 (34.9%) had not been included as author when they qualified, and 25 (58.1%) had seen authors included who did not qualify. A slight majority (n = 25; 58.1%) correctly identified authorship standards widely adopted by biomedical journals.

Conclusions

A surprising proportion of leaders in the HPE field had encountered unethical authorship practices. Despite widely disseminated authorship criteria, the findings suggest that offering authorship to those who do not qualify, or arguably worse, excluding those who should have been included, remains a common practice. The authors offer strategies to scholars, editors, and tenure and promotion committees to combat these practices.
An Early Finding of Keratoconus: Increase in Corneal Densitometry
Authors: Koc Mustafa , Tekin Kemal , Tekin Merve Inanc , Uzel Mehmet Murat , Kosekahya Pinar , Ozulken Kemal , Yilmazbas Pelin
Published: January 2018

Purpose:

To investigate the corneal densitometry in subclinical keratoconus with normal elevation and pachymetric parameters.

Methods:

Patients with clinical keratoconus in one eye and subclinical keratoconus in the fellow eye were identified. The study group was selected from patients with subclinical keratoconus who showed normal results from topographic and Belin-Ambrósio Enhanced Ectasia Display III (BAD) analysis (Kmean <47.2 diopters, inferior–superior asymmetry <1.4 diopters, and KISA% <60%, elevation <5 μm, PPIaverage <1.06, PPImaximum <1.44, ARTaverage <414 μm, ARTmaximum <339 μm, and final D <1.6). The control group was selected from candidates for refractive surgery. The densitometric analyses were performed through the Pentacam HR (Oculus, Germany).

Results:

The medical records of 3474 patients with keratoconus were examined, and 116 (3.3%) subclinical keratoconus cases were detected. Normal BAD analysis results were obtained from 38 patients (1.1%). The control group also consisted of 38 patients. There were no significant differences between the eyes with subclinical keratoconus and those of the control in corrected distance visual acuity and topographic, topometric, and tomographic parameters (P > 0.05). In all layers of the 0- to 2-mm zone and in the anterior and central layers of the 0- to 6-mm zone, corneal densitometry was significantly higher in the subclinical keratoconus than the control (P < 0.001). In discriminating eyes with subclinical keratoconus from normal, the anterior layer in the 0- to 2-mm zone showed the highest area under the curve (0.883; cutoff: 19.7; sensitivity: 75%; specificity: 90%) in a receiver operating characteristic analysis.

Conclusions:

The increase in densitometry in the central zone could be useful in detecting subclinical keratoconus.
High rate of acute pancreatitis during the Ramadan fast
Authors: Drozdinsky Genady , Agabaria Amir , Zuker-Herman Rona , J. Drescher Micheal , Bleetman Tony , Shiber Shachaf
Published: January 2018

Background

During the Ramadan fast Muslims celebrate a month of prayer, dawn-to-dusk fasting, and nightly feasts. We aimed to assess whether acute pancreatitis (AP) is more common during the Ramadan fast in individuals who celebrate it.

Patients and methods

The study was carried out at the emergency department of Rabin Medical Center, Israel. We compared the occurrence of AP in a fasting population and a nonfasting population during the Ramadan versus the rest of the year.

Results

Over the 10-year study period, 1167 patients were admitted to the emergency department with AP. Of these, 1069 (91.6%) were nonfasting and 98 (8.4%) were fasting. Of these, 17/98 (17.3%) fasting patients and 95/1069 (8.8%) nonfasting patients were admitted with AP during the Ramadan [relative risk: 1.12; 95% confidence interval (CI): 1.004–1.2; odds ratio (OR): 2.15; 95% CI: 1.23–3.8; P=0.01]. During the Ramadan, the rate of AP out of referrals was 0.1% (17/15 068) in fasting patients versus 0.004% (95/213 913) in nonfasting individuals (OR: 2.54; 95% CI: 1.5–4.25). During the other months of the year, the rate of AP out of referrals was 0.009% (81/86 072) in fasting patients versus 0.008% (974/1 202 405) in nonfasting individuals (OR: 1.16; 95% CI: 0.92–1.45; P<0.001).

Conclusion

We found a high rate of AP in the fasting population during the Ramadan. Physicians should be aware of this link and suspect it for fasting patients presenting with epigastric pain during the Ramadan fast.
Probiotics for Preterm Infants
Authors: van den Akker Chris H.P. , van Goudoever Johannes B. , Szajewska Hania , Embleton Nicholas D. , Hojsak Iva , Reid Daan , Shamir Raanan ,   ESPGHAN Working Group for Probiotics, Prebiotics & Committee on Nutrition
Published: January 2018

Objectives:

Several randomized controlled trials (RCTs) on the use of probiotics to reduce morbidity and mortality in preterm infants have provided inconsistent results. Although meta‐analyses that group all of the used strains together are suggesting efficacy, it is not possible to determine the most effective strain that is more relevant to the clinician. We therefore used a network meta‐analysis (NMA) approach to identify strains with greatest efficacy.

Methods:

A PubMed search identified placebo‐controlled or head‐to‐head RCTs investigating probiotics in preterm infants. From trials that recorded mortality, necrotizing enterocolitis, late‐onset sepsis, or time until full enteral feeding as outcomes, data were extracted and Bayesian hierarchical random‐effects models were run to construct a NMA.

Results:

Fifty‐one RCTs involving 11,231 preterm infants were included. Most strains or combinations of strains were only studied in one or a few RCTs. Only 3 of 25 studied probiotic treatment combinations showed significant reduction in mortality rates. Seven treatments reduced necrotizing enterocolitis incidence, 2 reduced late‐onset sepsis, and 3 reduced time until full enteral feeding. There was no clear overlap of strains, which were effective on multiple outcome domains.

Conclusions:

This NMA showed efficacy in reducing mortality and morbidity only in a minority of the studied strains or combinations. This may be due to an inadequate number, or size, of RCTs, or due to a true lack of effect for certain species. Further large and adequately powered RCTs using strains with the greatest apparent efficacy will be needed to more precisely define optimal treatment strategies.
Character of Gluteal Region Morphology in Young Chinese Females
Authors: Cao Saisai , Peng Zhe , Bi Ye , Liu Yan , Yang Kai , Li Guangxue , Tang Hui , Zang Huiran , Qian Youlei , Liu Xiangyu , Song Ping , Pu Lee L.Q. , Mu Lan
Published: January 2018

Background

The female gluteal morphology is an important secondary sexual characteristic and helps accentuate and define the female body shape. Despite the increasing prevalence of gluteal augmentations in our country, little data exist regarding the morphology of the gluteal region in young Chinese females. This study analyzed a convenience sample of Chinese females and their gluteal region.

Methods

Data, measurements, and photos of the following parameters were taken: age, weight, height, and body mass index (BMI). Morphology was classified into four types: A shape, V shape, round shape, and square shape. Aesthetic characteristics of each buttock were recorded. Height, weight, BMI, and gluteal projection ratio differences in different shape groups were analyzed.

Results

The study sample consisted of 103 women, with ages from 23 to 27 years. The V-shaped buttock was not found in this sample. The A shape, square shape, and round shape occupied 55.3%, 38.8%, and 5.8% accordingly. Short infragluteal fold, supragluteal fossettes, lateral depression, and V-shaped crease appeared in 42.7%, 14.6%, 11.7%, and 2.9% of samples, respectively. Of the 103 samples, 39 (37.9%) fulfilled the aesthetic gluteal projection(ratio ≥ 2). The average BMI was statistically significant between each gluteal shape (P = 0.009). Height, weight, and gluteal projection ratio showed no significant difference with the buttock shapes.

Conclusions

We are the first to describe gluteal morphology in young Chinese woman using gluteal anthropometrics. The findings of the study may provide a guideline for plastic surgeons who perform gluteal augmentation in Asian patients.
Airway and ventilation management strategies for hemorrhagic shock. To tube, or not to tube, that is the question!
Authors: Hudson Anthony J. , Strandenes Geir , Bjerkvig Christopher K. , Svanevik Marius , Glassberg Elon
Published: January 2018

abstract

Many standard trauma management guidelines advocate the early use of endotracheal intubation (ETI) and positive pressure ventilation as key treatment interventions in hemorrhagic shock. The evidence for using these airway and ventilation strategies to manage a circulation problem is unclear. The potentially harmful effects of drug-assisted intubation and positive pressure ventilation include reduced cardiac output, apnea, hypoxia, hypocapnea (due to inadvertent hyperventilation), and unnecessarily prolonged on-scene times. Conversely, the beneficial effects of spontaneous negative pressure ventilation on cardiac output are well described. Few studies, however, have attempted to explore the potential advantages of a strategy of delayed intubation and ventilation (together with a policy of aggressive volume replacement) in shocked trauma patients. Given the lack of evidence, the decision making around how, when, and where to subject shocked trauma patients to intubation and positive pressure ventilation remains complex. If providers choose to delay intubation, they must have the appropriate skills to safely manage the airway and recognize the need for subsequent intervention. If they decide to perform intubation and positive pressure ventilation, they must understand the potential risks and how best to minimize them. We suggest that for patients with hemorrhagic shock who do not have a compromised airway and who are able to maintain adequate oxygen saturation (or mentation if monitoring is unreliable), a strategy of delayed intubation should be strongly encouraged.

LEVEL OF EVIDENCE

Review article, level IV.
Implementation of an Asthma Self-Management Education Guideline in the Emergency Department
Authors: Roberts Eric , Velsor-Friedrich Barbara , Keough Vicki
Published: January 2018

Patients often present to emergency departments (EDs) for the management of chronic asthma. Because of the nature of ED care, national guideline recommendations for asthma education are generally not initiated in the ED. There is evidence that asthma education can have a positive effect on patient outcomes (P. Gibson et al., 2009
;
H. Powell & P. Gibson, 2009). This study examines the feasibility of implementing an asthma self-management guideline in a tertiary care center ED. Despite protocol utilization by physicians (87%), nurse practitioners and physician assistants (66.7%), and nurses (41.7%), total compliance with national guideline was accomplished in only 25.93% of cases. Barriers to protocol implementation included staff education, high workload, rapid turnover, and competing initiatives within the department. Linear regression analysis identified high daily census as a predictor of protocol noncompliance (p = 0.033).
Mechanical power curve measured in the wake of pied flycatchers indicates modulation of parasite power across flight speeds
Authors: Johansson L. Christoffer , Maeda Masateru , Henningsson Per , Hedenström Anders
Published: January 2018

How aerodynamic power required for animal flight varies with flight speed determines optimal speeds during foraging and migratory flight. Despite its relevance, aerodynamic power provides an elusive quantity to measure directly in animal flight. Here, we determine the aerodynamic power from wake velocity fields, measured using tomographical particle image velocimetry, of pied flycatchers flying freely in a wind tunnel. We find a shallow U-shaped power curve, which is flatter than expected by theory. Based on how the birds vary body angle with speed, we speculate that the shallow curve results from increased body drag coefficient and body frontal area at lower flight speeds. Including modulation of body drag in the model results in a more reasonable fit with data than the traditional model. From the wake structure, we also find a single starting vortex generated from the two wings during the downstroke across flight speeds (1–9 m s−1). This is accomplished by the arm wings interacting at the beginning of the downstroke, generating a unified starting vortex above the body of the bird. We interpret this as a mechanism resulting in a rather uniform downwash and low induced power, which can help explain the higher aerodynamic performance in birds compared with bats.
Differential influences of allometry, phylogeny and environment on the rostral shape diversity of extinct South American notoungulates
Authors: Gomes Rodrigues Helder , Cornette Raphaël , Clavel Julien , Cassini Guillermo , Bhullar Bhart-Anjan S.  , Fernández-Monescillo Marcos , Moreno Karen , Herrel Anthony , Billet Guillaume
Published: January 2018

Understanding the mechanisms responsible for phenotypic diversification, and the associated underlying constraints and ecological factors represents a central issue in evolutionary biology. Mammals present a wide variety of sizes and shapes, and are characterized by a high number of morphological convergences that are hypothesized to reflect similar environmental pressures. Extinct South American notoungulates evolved in isolation from northern mammalian faunas in highly disparate environments. They present a wide array of skeletal phenotypes and convergences, such as ever-growing dentition. Here, we focused on the origins of the rostral diversity of notoungulates by quantifying the shape of 26 genera using three-dimensional geometric morphometric analysis. We tested the influence of allometry and phylogeny on rostral shape and evaluated rates of evolutionary change in the different clades. We found strong allometric and phylogenetic signals concerning the rostral shape of notoungulates. Despite convergent forms, we observed a diffuse diversification of rostral shape, with no significant evidence of influence by large-scaled environmental variation. This contrasts with the increase in dental crown height that occurred in four late-diverging families in response to similar environmental pressures. These results illustrate the importance of considering both biological components and evolutionary rates to better understand some aspects of phenotypic diversity.