bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutzerinteresse an mobilen digitalen Assistenzsystemen zur Förderung körperlicher Aktivität bei Studierenden und Mitarbeitern einer Universität
Authors: Salzwedel Annett , Rabe Sophie , Zahn Thomas , Neuwirth Julia , Eichler Sarah , Haubold Kathrin , Wachholz Anne , Reibis Rona , Völler Heinz
Published: April 2017

Hintergrund Einem Großteil der Bevölkerung gelingt es trotz ausreichenden Wissens um die protektiven Effekte nicht, ausreichende körperliche Aktivität in den Alltag zu integrieren. Digitale Assistenzsysteme könnten hierbei unterstützend eingesetzt werden. Dies setzt jedoch das Interesse potentieller Nutzer voraus.

Methode In einer Online-Befragung wurden im Juni/Juli 2015 Mitarbeiter und Studierende der Universität Potsdam zum individuellen Ausmaß der sportlichen Aktivität, dem Interesse an elektronischer Trainingsunterstützung und weiteren Parametern befragt.

Ergebnis 1217 Studierende und 485 Mitarbeiter (67,3 bzw. 67,5% Frauen, 26±4,9 bzw. 42,7±11,7 Jahre) nahmen an der Studie teil. Die empfohlene sportliche Aktivität (≥3 Tage bzw. 150 min/Woche) wurde von 70,1% der Mitarbeiter und 52,7% der Studierenden nicht erreicht. Innerhalb dieser Gruppen zeigten 53,2% (Studierende) bzw. 44,2% (Mitarbeiter), unabhängig von Alter, Geschlecht, BMI bzw. Bildungsniveau, Interesse an einer elektronischen Trainingsunterstützung.

Schlussfolgerung Auch in jüngeren Bevölkerungsgruppen mit hohem Bildungsniveau ist die Mehrzahl der Personen unzureichend körperlich aktiv. Ein Interesse an Trainingsunterstützung besteht in etwa der Hälfte dieser sportlich inaktiven Gruppe. Dies legt den Schluss nahe, dass der personalisierte Einsatz mobiler Assistenzsysteme für die positive Beeinflussung des Lebensstils zunehmend an Bedeutung gewinnen könnte.
Fully inkjet printed flexible resistive memory
Authors: Huber B. , Popp P. B. , Kaiser M. , Ruediger A. , Schindler C.
Published: April 2017

Resistively switching memory cells (ReRAM) are strong contenders for next-generation non-volatile random access memories. In this paper, we present ReRAM cells on flexible substrates consisting of Ag/spin-on-glass/PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate). The complete cell is fabricated using a standard inkjet printer without additional process steps. Investigations on the spin-on-glass insulating layer showed that low sintering temperatures are sufficient for good switching behavior, providing compatibility with various foils. The cells feature low switching voltages, low write currents, and a high ratio between high and low resistance state of 104. Combined with excellent switching characteristics under bending conditions, these results pave the way for low-power and low-cost memory devices for future applications in flexible electronics.
Segment-scale, force-level theory of mesoscopic dynamic localization and entropic elasticity in entangled chain polymer liquids
Authors: Dell Zachary E. , Schweizer Kenneth S.
Published: April 2017

We develop a segment-scale, force-based theory for the breakdown of the unentangled Rouse model and subsequent emergence of isotropic mesoscopic localization and entropic elasticity in chain polymer liquids in the absence of ergodicity-restoring anisotropic reptation or activated hopping motion. The theory is formulated in terms of a conformational N-dynamic-order-parameter generalized Langevin equation approach. It is implemented using a universal field-theoretic Gaussian thread model of polymer structure and closed at the level of the chain dynamic second moment matrix. The physical idea is that the isotropic Rouse model fails due to the dynamical emergence, with increasing chain length, of time-persistent intermolecular contacts determined by the combined influence of local uncrossability, long range polymer connectivity, and a self-consistent treatment of chain motion and the dynamic forces that hinder it. For long chain melts, the mesoscopic localization length (identified as the tube diameter) and emergent entropic elasticity predictions are in near quantitative agreement with experiment. Moreover, the onset chain length scales with the semi-dilute crossover concentration with a realistic numerical prefactor. Distinctive novel predictions are made for various off-diagonal correlation functions that quantify the full spatial structure of the dynamically localized polymer conformation. As the local excluded volume constraint and/or intrachain bonding spring are softened to allow chain crossability, the tube diameter is predicted to swell until it reaches the radius-of-gyration at which point mesoscopic localization vanishes in a discontinuous manner. A dynamic phase diagram for such a delocalization transition is constructed, which is qualitatively consistent with simulations and the classical concept of a critical entanglement degree of polymerization.
The one-dimensional camelback potential in the parallel dipole line trap: Stability conditions and finite size effect
Authors: Gunawan Oki , Virgus Yudistira
Published: April 2017

We recently demonstrated a magnetic parallel dipole line (PDL) system that serves as a unique diamagnetic trap with a fascinating one-dimensional camelback potential along its longitudinal axis. The system can be realized with a pair of transversely magnetized cylindrical magnets and a cylindrical graphite rod as the trapped object. We present more detailed experimental and theoretical studies of the finite size effect of the rod and its impact on the stability and oscillation dynamics of the trap. We show that the camelback potential effect only occurs when the length of the PDL system is beyond certain critical length (LC). The length of the trapped rod determines the “effective camelback potential” and is subject to maximum and minimum values for the trap to be stable. Both length and radius of the rod determine the damping dynamics or the quality factor of the oscillator. These characteristics are important for designing the PDL trap system for various sensing applications, for example, we demonstrated a PDL trap gas viscometer system through measurement of the oscillation damping time constant.
Instabilities of nanofluid flow displacements in porous media
Authors: Dastvareh Behnam , Azaiez Jalel
Published: April 2017

Thanks to a number of advantageous characteristics, nanofluids are widely used in a variety of fluid flow systems. In porous media flows, the presence of nanoparticles can have dramatic effects on the flow dynamics and in particular on viscous fingering instabilities that develop when a less viscous fluid displaces a more viscous one. In the present study, these effects have been investigated both analytically and numerically using linear stability analysis (LSA) and non-linear simulations. The LSA problem was solved analytically using step function approximation, and general conclusions about the effects of nanofluids on the instability were derived from long wave expansion and cutoff wave number analyses. Furthermore, the quasi-steady-state approximation was used to expand the results of the LSA to diffusing initial concentration profiles, and simulations of the full non-linear problem have been carried out using a Hartley-transform based pseudo-spectral method. Results revealed that nanoparticles cannot make an otherwise stable flow unstable but can enhance or attenuate the instability of an originally unstable flow. In particular it was found that increases in the nanoparticles deposition rate or their rate of diffusion have both destabilizing effects. Furthermore, nanoparticles deposition can change the initial monotonically decreasing viscosity distribution to a non-monotonic one and results in the development of vortex dipoles. Analyses of vortex structures along with the viscosity distributions allowed to explain the observed trends and the resulting finger configurations.
Dripping to jetting transition for cross-flowing liquids
Authors: Bertrandias A. , Duval H. , Casalinho J. , Giorgi M. L.
Published: April 2017

We experimentally study drops formed from a nozzle into an immiscible, cross-flowing phase. Depending on the operating conditions, drops are generated either in dripping or jetting mode. We investigate the impact of the continuous and dispersed phase velocities, dispersed phase viscosity, and interfacial tension on the drop generation mode and size. We find that a dripping to jetting transition (DJT) takes place at a critical inner Weber number, a function of the outer capillary and Ohnesorge numbers. Two jetting regimes occur depending on the phase velocity ratio. When the continuous phase velocity is significantly greater (respectively lower) than the dispersed phase velocity, jet narrowing (respectively widening) occurs. In jet widening, the critical inner Weber number depends little on the outer capillary number whereas in jet narrowing, it sharply decreases as the outer capillary number increases. We propose a comprehensive model to describe the DJT based on the attached drop equation of motion. The model satisfactorily predicts the DJT and the effect of the outer capillary number on the critical inner Weber number. It also well accounts for the drop diameter in jet narrowing.
Structural connectome topology relates to regional BOLD signal dynamics in the mouse brain
Authors: Sethi Sarab S. , Zerbi Valerio , Wenderoth Nicole , Fornito Alex , Fulcher Ben D.
Published: April 2017

Brain dynamics are thought to unfold on a network determined by the pattern of axonal connections linking pairs of neuronal elements; the so-called connectome. Prior work has indicated that structural brain connectivity constrains pairwise correlations of brain dynamics (“functional connectivity”), but it is not known whether inter-regional axonal connectivity is related to the intrinsic dynamics of individual brain areas. Here we investigate this relationship using a weighted, directed mesoscale mouse connectome from the Allen Mouse Brain Connectivity Atlas and resting state functional MRI (rs-fMRI) time-series data measured in 184 brain regions in eighteen anesthetized mice. For each brain region, we measured degree, betweenness, and clustering coefficient from weighted and unweighted, and directed and undirected versions of the connectome. We then characterized the univariate rs-fMRI dynamics in each brain region by computing 6930 time-series properties using the time-series analysis toolbox, hctsa. After correcting for regional volume variations, strong and robust correlations between structural connectivity properties and rs-fMRI dynamics were found only when edge weights were accounted for, and were associated with variations in the autocorrelation properties of the rs-fMRI signal. The strongest relationships were found for weighted in-degree, which was positively correlated to the autocorrelation of fMRI time series at time lag τ = 34 s (partial Spearman correlation ρ=0.58), as well as a range of related measures such as relative high frequency power (f > 0.4 Hz: ρ=−0.43). Our results indicate that the topology of inter-regional axonal connections of the mouse brain is closely related to intrinsic, spontaneous dynamics such that regions with a greater aggregate strength of incoming projections display longer timescales of activity fluctuations.
Calculations of atomic magnetic nuclear shielding constants based on the two-component normalized elimination of the small component method
Authors: Yoshizawa Terutaka , Zou Wenli , Cremer Dieter
Published: April 2017

A new method for calculating nuclear magnetic resonance shielding constants of relativistic atoms based on the two-component (2c), spin-orbit coupling including Dirac-exact NESC (Normalized Elimination of the Small Component) approach is developed where each term of the diamagnetic and paramagnetic contribution to the isotropic shielding constant σiso is expressed in terms of analytical energy derivatives with regard to the magnetic field B and the nuclear magnetic moment 𝝁. The picture change caused by renormalization of the wave function is correctly described. 2c-NESC/HF (Hartree-Fock) results for the σiso values of 13 atoms with a closed shell ground state reveal a deviation from 4c-DHF (Dirac-HF) values by 0.01%–0.76%. Since the 2-electron part is effectively calculated using a modified screened nuclear shielding approach, the calculation is efficient and based on a series of matrix manipulations scaling with (2M)3 (M: number of basis functions).
Effect of viscous dissipation on the convective instability induced by inclined temperature gradients in a non-Darcy porous medium with horizontal throughflow
Authors: Roy Kamalika , Murthy P. V. S. N.
Published: April 2017

The linear stability of the convective flow induced by an inclined temperature gradient in a horizontal porous layer with horizontal mass flow is studied. The momentum equation is modelled using the Brinkman model. The contribution of viscous dissipation to the medium is taken into account. The governing parameters are the Gebhart number (Ge), horizontal Rayleigh number (RaH), Darcy number (Da), and Péclet number (Pe). Da→0 represents the Darcy regime and Da→∞ represents the clear fluid regime. The basic flow is considered to be a superposition of the flow induced by the inclined temperature gradient and the horizontal mass flow. This flow is termed as the Hadley-Prats flow. The stability of this base flow in the Brinkman regime is investigated. The longitudinal and transverse rolls are discussed. A comparison has been made between the effect of viscous dissipation on the Hadley-Prats flow in the Darcy model and the present results with Da→0. With the increase in the Darcy number, the longitudinal rolls come out as the favorable mode of instability except for some special cases. Viscous dissipation has a dual role on the convective stability depending on the direction of the horizontal throughflow in both the Darcy and the Brinkman regimes.
Oxidation induced stress in SiO2/SiC structures
Authors: Li Xiuyan , Ermakov Alexei , Amarasinghe Voshadhi , Garfunkel Eric , Gustafsson Torgny , Feldman Leonard C.
Published: April 2017

Physical stress in SiO2/SiC stacks formed by the thermal oxidation of SiC is studied experimentally through both room temperature ex-situ and variable temperature (25–1150 °C) in-situ investigations. Mechanisms giving rise to the stress are a thermal component, associated with differences in thermal expansion coefficients of the oxide and the substrate, and an intrinsic component associated with the different atomic densities and structure of the film and substrate. Ex-situ results show a ∼108 Pa compressive stress in the SiO2 film in a SiO2/SiC stack with a strong crystal face dependence (C face(000ī) and Si face (0001)) and processing (temperature, growth rate) dependence. Real-time stress determination demonstrates that at temperatures above ∼900 °C, the total intrinsic stress and a portion of the thermal stress may be relieved. On the basis of these findings, a viscous model is proposed to discuss the stress relaxation.
Nonmechanical compact probe for cross-sectional velocity measurement based on differential laser Doppler velocimetry
Authors: Maru K. , Katsumi S. , Matsuda R.
Published: April 2017

In this study, we propose and demonstrate a nonmechanical compact probe for cross-sectional velocity measurement based on differential laser Doppler velocimetry. The system introduces a method that combines simultaneous multipoint measurement using spatial encoding and nonmechanical scanning of measurement points, in which spatially encoded measurement points aligned along the transverse direction are scanned in the axial direction by changing the wavelength. The use of a waveguide-type LiNbO3 phase shifter array for serrodyne frequency shifting is feasible for the system based on fiber optics with an easily handled probe. To miniaturize the probe, a multimode fiber is introduced in the receiving optics and the parameters of the lens system in the transmitting optics are optimized. For the experiment, an eight-channel probe was assembled on an aluminum plate with an 8 cm × 8 cm area size. The experimental results reveal that the cross-sectional two-dimensional velocity distribution was successfully measured using the easily handled compact probe for the first time.
Control of plasmon resonance by mode coupling in metal-dielectric nanostructures
Authors: Pelzman Charles , Cho Sang-Yeon
Published: April 2017

We present an approach to control the spectral response of plasmonic metal-dielectric nanostructure through resonant scattering. The resonant coupling scheme is based on mixing of a broad surface state with a narrow resonant state. The spectral response of the Au-Si nanostructure is highly tunable by controlling the coupling strength of the two states. The nanostructure also shows a highly asymmetric and narrow resonance profile in the reflection spectrum. The calculated quality factor of a resonant mode in the proposed structure is about 93 around λ0 = 750 nm. The proposed metal-dielectric nanostructure has great potential to improve the quality factor of the existing surface plasmon resonance systems.
Thermodynamic understanding and analytical modeling of interfacial SiO2 scavenging in HfO2 gate stacks on Si, SiGe, and SiC
Authors: Li Xiuyan , Yajima Takeaki , Nishimura Tomonori , Toriumi Akira
Published: April 2017

This work thermodynamically and experimentally generalizes the interfacial SiO2 scavenging in HfO2 gate stacks from on Si to on other channel materials including SiGe and SiC and proposes a generalized formulation for this process. By paying attention to the Si chemical potential in the SiO2 interfacial layer (SiO2-IL) significantly affected by the substrate, it clarifies that Si in the substrate is indispensable to trigger the scavenging process. Thanks to this understanding, we demonstrate that the scavenging is extendable to next generation of channel materials containing Si such as SiGe and SiC with well-controlled high-k gate stacks. In addition, via formulating the diffusion-reaction-diffusion kinetics, an analytical relation like the Deal-Grove model is obtained for SiO2-IL scavenging in high-k gate stacks.
Correlating thermoelectric properties with microstructure in Bi0.8Sb0.2 thin films
Authors: Siegal M. P. , Lima-Sharma A. L. , Sharma P. A. , Rochford C.
Published: April 2017

The room temperature electronic transport properties of 100 nm-thick thermoelectric Bi0.8Sb0.2 films, sputter-deposited onto quartz substrates and post-annealed in an ex-situ furnace, systematically correlate with the overall microstructural quality, improving with increasing annealing temperature until close to the melting point for the alloy composition. The optimized films have high crystalline quality with ∼99% of the grains oriented with the trigonal axis perpendicular to the substrate surface. Film resistivities and Seebeck coefficients are accurately measured by preventing deleterious surface oxide formation via a SiN capping layer and using Nd-doped Al for contacts. The resulting values are similar to single crystals and significantly better than previous reports from films and polycrystalline bulk alloys.
Ultrafast chemical-free cell lysis by high speed stream collision induced by surface acoustic waves
Authors: Wang Wenbo , Chen Yishan , Farooq Umar , Xuan Weipeng , Jin Hao , Dong Shurong , Luo Jikui
Published: April 2017

This paper reports on a surface acoustic wave (SAW) based cell lysis device on a LiNbO3 substrate by utilizing high speed collision of cells, which are accelerated by acoustic streaming. With varying working powers, cell lysis was achieved within 20 s and more than 95% lysis efficiency. The cell solution volume effect on SAW based lysis was also investigated and proved that it is not the main issue. With the CCK8 based viability test and verification of cell contents by electrophoresis, the efficient lysis results of our devices have been verified.
Control of pn-junction turn-on voltage in 4H-SiC merged PiN Schottky diode
Authors: Park Junbo , Park Kun-Sik , Won Jong-il , Kim Ki-hwan , Koo Sangmo , Kim Sang-gi , Mun Jae-Kyoung
Published: April 2017

We present numerical simulation results and experimental measurements that explain the physical mechanism behind the high critical voltage, Vcrit, required to turn on a pn junction in a merged PiN Schottky (MPS) diode. The 2D simulation of potential distribution within a unit MPS cell demonstrated that the potential gradient set by the Schottky junction raises the potential barrier formed at the pn junction, thereby increasing Vcrit. Based on this knowledge, we propose that changing the ratio of the Schottky contact and the p+ region area, as well as shallow p-doping of the Schottky interface, can be used to control the magnitude of Vcrit. We present simulation and measurement results that demonstrate the feasibility of our approach.
Microscopic theory for radiation-induced zero-resistance states in 2D electron systems: Franck-Condon blockade
Authors: Iñarrea Jesús
Published: April 2017

We present a microscopic model on radiation-induced zero resistance states according to a novel approach: Franck-Condon physics and blockade. Zero resistance states rise up from radiation-induced magnetoresistance oscillations when the light intensity is strong enough. The theory begins with the radiation-driven electron orbit model that proposes an interplay of the swinging nature of the radiation-driven Landau states and the presence of charged impurity scattering. When the intensity of radiation is high enough, the driven-Landau states (vibrational states) involved in the scattering process are spatially far from each other and the corresponding electron wave functions no longer overlap. As a result, a drastic suppression of the scattering probability takes place and current and magnetoresistance exponentially drop. Finally, zero resistance states rise up. This is an application to magnetotransport in two-dimensional electron systems of the Franck-Condon blockade, based on the Franck-Condon physics which in turn stems from molecular vibrational spectroscopy.
Scavenging energy from human walking through a shoe-mounted piezoelectric harvester
Authors: Fan Kangqi , Liu Zhaohui , Liu Haiyan , Wang Liansong , Zhu Yingmin , Yu Bo
Published: April 2017

This study presents a shoe-mounted nonlinear piezoelectric energy harvester (PEH) with intent to capture energy from human walking. The PEH consists of a piezoelectric cantilever beam magnetically coupled to a ferromagnetic ball and a crossbeam. A sleeve is included to guide the travel of the ball. Experimental measurements and theoretical simulations demonstrate that the proposed design can collect energy from diverse excitation sources with different directions produced by the foot, including vibrations, swing motions, and the compressive force. The ball and the crossbeam sense the swing motion and the compressive force, respectively, and then actuate the piezoelectric beam to function. The piezoelectric beam senses the vibration along the tibial axis and generates electricity. The proposed PEH achieves the superposition of these excitations and generates multiple peaks in voltage output within one gait cycle. The output power generated by the fabricated prototype ranges from 0.03 mW to 0.35 mW when the walking velocity varies from 2 km/h to 8 km/h.
Rapid mechanochemical synthesis of amorphous alloys
Authors: Hatchard T. D. , Genkin A. , Obrovac M. N.
Published: April 2017

A rapid method for preparing amorphous alloys has been developed utilizing a SPEX high energy ball mill. Parameters such as ball size, mass of balls and milling time, were systematically optimized to prepare amorphous alloys quickly. Amorphous alloys previously not thought possible to synthesize by means of SPEX milling were made amorphous by the new method. When applied to the preparation of Sn-Co-C and Si-Fe alloys, the method was found to produce fully amorphous alloys in a matter of hours instead of days or weeks of milling by traditional techniques. Electrochemical performance of the alloys produced by the rapid milling technique in Li cells was found to be the same or superior to alloys produced by the more time consuming methods, confirming their amorphous microstructure.
Understanding forest fire patterns and risk in Nepal using remote sensing, geographic information system and historical fire data
Authors: Matin Mir A. , Chitale Vishwas Sudhir , Murthy Manchiraju S. R. , Uddin Kabir , Bajracharya Birendra , Pradhan Sudip
Published: April 2017

Forest fire is one of the key drivers of forest degradation in Nepal. Most of the forest fires are human-induced and occur during the dry season, with ~89% occurring in March, April and May. The inaccessible mountainous terrain and narrow time window of occurrence complicate suppression efforts. In this paper, forest fire patterns are analysed based on historical fire incidence data to explore the spatial and temporal patterns of forest fires in Nepal. Three main factors are involved in the ignition and spread of forest fires, namely fuel availability, temperature and ignition potential. Using these factors a spatially distributed fire risk index was calculated for Nepal based on a linear model using weights and ratings. The input parameters for the risk assessment model were generated using remote sensing based land cover, temperature and active fire data, and topographic data. A relative risk ranking was also calculated for districts and village development committees (VDCs). In total, 18 out of 75 districts were found with high risk of forest fires. The district and VDC level fire risk ranking could be utilised by the Department of Forest for prioritisation, preparedness and resource allocation for fire control and mitigation.
Climatic influences on interannual variability in regional burn severity across western US forests
Authors: Abatzoglou John T. , Kolden Crystal A. , Williams A. Park , Lutz James A. , Smith Alistair M. S.
Published: April 2017

Interannual variability in burn severity is assessed across forested ecoregions of the western United States to understand how it is influenced by variations in area burned and climate during 1984–2014. Strong correlations (|r| > 0.6) between annual area burned and climate metrics were found across many of the studied regions. The burn severity of individual fires and fire seasons was weakly, but significantly (P < 0.05), correlated with burned area across many regions. Interannual variability in fuel dryness evaluated with fuel aridity metrics demonstrated weak-to-moderate (|r| >0.4) relationships with regional burn severity, congruent with but weaker than those between climate and area burned for most ecoregions. These results collectively suggest that irrespective of other factors, long-term increases in fuel aridity will lead to increased burn severity in western United States forests for existing vegetation regimes.
Titling indigenous communities protects forests in the Peruvian Amazon
Authors: Blackman Allen , Corral Leonardo , Lima Eirivelthon Santos , Asner Gregory P.
Published: April 2017

Significance

Developing countries are increasingly granting local communities legal title to forests. Almost a third of forests in the global south are now managed by local communities, more than twice the share currently found in protected areas. However, we know little about the effects of titling on forest clearing and disturbance, which remain urgent problems. We use community-level longitudinal data derived from high-resolution satellite images, along with statistical techniques that control for confounding factors, to measure the effect of titling indigenous communities in the Peruvian Amazon. Results indicate that titling significantly reduces both clearing and disturbance, at least in the short term. The implication is that awarding formal land titles to local communities can protect forests.
Accelerated body size evolution during cold climatic periods in the Cenozoic
Authors: Clavel Julien , Morlon Hélène
Published: April 2017

Significance

We do not have a clear understanding of the impact of past climatic changes on evolution. This question has been investigated for a few lineages in the fossil record, but a global vision is still lacking. Here, we present a phylogenetic comparative framework for examining the effects of past climate changes on morphological evolution with data from almost all existing birds and mammals. We show that global temperatures fluctuations through the Cenozoic impacted body size evolution. The evolution of body size was faster during periods of global cooling in most of the groups, challenging the hypothesis that evolution is faster under warm climates. These results have important implications for our understanding of how ongoing climate changes may affect future evolution.
Posterior parietal cortex contains a command apparatus for hand movements
Authors: Rathelot Jean-Alban , Dum Richard P. , Strick Peter L.
Published: April 2017

Significance

The primate hand has evolved into a specialized sensorimotor device that can grasp, explore, and manipulate objects with extraordinary skill. The frontal lobe is generally thought to be the exclusive source of descending commands to the spinal cord to control hand movements. Here, we identify a region within the parietal lobe that could also contribute commands to control hand movements directly at spinal levels. Intracortical stimulation in a lateral region in area 5 of posterior parietal cortex reliably evokes hand movements. Corticospinal neurons in this region make disynaptic connections with hand motoneurons. These observations suggest that a region within lateral area 5 contains a unique command apparatus that could assist in generating dexterous finger movements required during haptic behavior.
Reach and speed of judgment propagation in the laboratory
Authors: Moussaïd Mehdi , Herzog Stefan M. , Kämmer Juliane E. , Hertwig Ralph
Published: April 2017

Significance

Individual judgments, feelings, and behaviors can spread from person to person in social networks, similarly to the propagation of infectious diseases. Despite major implications for many social phenomena, the underlying social-contagion processes are poorly understood. We examined how participants’ perceptual judgments spread from one person to another and across diffusion chains. We gauged the speed, reach, and scale of social contagion. Judgment propagation tended to slow down with increasing social distance from the source. Crucially, it vanished beyond a social horizon of three to four people. These results advance the understanding of some of the mechanisms underlying social-contagion phenomena as well as their scope across domains as diverse as political mobilization, health practices, and emotions.
Nit1 is a metabolite repair enzyme that hydrolyzes deaminated glutathione
Authors: Peracchi Alessio , Veiga-da-Cunha Maria , Kuhara Tomiko , Ellens Kenneth W. , Paczia Nicole , Stroobant Vincent , Seliga Agnieszka K. , Marlaire Simon , Jaisson Stephane , Bommer Guido T. , Sun Jin , Huebner Kay , Linster Carole L. , Cooper Arthur J. L. , Van Schaftingen Emile
Published: April 2017

Significance

The genomes of the vast majority of eukaryotes encode a protein [named nitrilase-like protein 1 (Nit1) in humans and mice] whose enzymatic function has long been unknown. We show here that the mammalian Nit1 and the corresponding yeast protein efficiently hydrolyze the deaminated form of the common intracellular antioxidant glutathione. In turn, deaminated glutathione can be produced by a side activity of numerous transaminases. Thus, Nit1 repairs an undesired product, arising from the slow (and erroneous) transformation of an important metabolite by some abundant intracellular enzymes. The importance of this Nit1 function is underscored by the finding that enzymes with the same activity occur in
Escherichia coli
and in other glutathione-producing bacteria.
Parietal neurons encode expected gains in instrumental information
Authors: Foley Nicholas C. , Kelly Simon P. , Mhatre Himanshu , Lopes Manuel , Gottlieb Jacqueline
Published: April 2017

Significance

We examine how the brain guides active sensing in awake, behaving primates using a paradigm in which information sampling is dissociated from reinforcement variables, such as cumulative future reward or reward prediction errors. We show that target selective cells in lateral intraparietal cortex encode decision variables based on expected gains in instrumental information—the extent to which a visual cue, when discriminated, is expected to reduce the uncertainty of a subsequent action.
Trio-based exome sequencing arrests de novo mutations in early-onset high myopia
Authors: Jin Zi-Bing , Wu Jinyu , Huang Xiu-Feng , Feng Chun-Yun , Cai Xue-Bi , Mao Jian-Yang , Xiang Lue , Wu Kun-Chao , Xiao Xueshan , Kloss Bethany A. , Li Zhongshan , Liu Zhenwei , Huang Shenghai , Shen Meixiao , Cheng Fei-Fei , Cheng Xue-Wen , Zheng Zhi-Li , Chen Xuejiao , Zhuang Wenjuan , Zhang Qingjiong , Young Terri L. , Xie Ting , Lu Fan , Qu Jia
Published: April 2017

Significance

Because preschool children encounter fewer risks from environmental pressures, we propose that the condition of early-onset high myopia (EOHM) is driven by a genetic predisposition more than by environmental factors. In this study, we recruited 18 familial trios to decipher the genetic predisposition using whole-exome sequencing. We identified a cluster of unique genes linked to EOHM, as well as mutations in the reported genes. Notably, we showed that both rare inherited mutations and de novo mutations significantly contributed to EOHM. Expression profiling in ocular tissues and mutant mouse phenotyping demonstrated the pathogenicity of mutations in a unique gene,
BSG
. Our results provide insights into the genetic basis and molecular mechanisms of childhood high myopia.
Uplift-driven diversification in the Hengduan Mountains, a temperate biodiversity hotspot
Authors: Xing Yaowu , Ree Richard H.
Published: April 2017

Significance

Why do so many species occur in mountains? A popular but little-tested hypothesis is that tectonic uplift creates environmental conditions (new habitats, dispersal barriers, etc.) that increase the rate at which resident species divide and evolve to form new ones. In China’s Hengduan Mountains region, a biodiversity hotspot uplifted over the last 8 million years, this rate does in fact show a significant increase during that time, relative to the rate for adjacent older mountains, and to the rate of species immigration. The Hengduan Mountains flora is thus made up disproportionately of species that evolved within the region during its uplift, supporting the original hypothesis and helping to explain the prevalence of mountains as global biodiversity hotspots.
Membrane fission by protein crowding
Authors: Snead Wilton T. , Hayden Carl C. , Gadok Avinash K. , Zhao Chi , Lafer Eileen M. , Rangamani Padmini , Stachowiak Jeanne C.
Published: April 2017

Significance

The division of membrane-bound compartments into smaller, separate volumes is essential to cells. The process of membrane fission is required for the separation of two membrane compartments. The prevailing view has been that to drive fission, proteins must contain specific structural features such as curved scaffolds and wedge-like membrane insertions. In contrast, this work demonstrates a more general mechanism, in which crowding among membrane-bound proteins drives fission. Like a compressed gas, collisions among crowded proteins generate pressure that can stretch, bend, and ultimately disrupt membrane surfaces, leading to fission. The discovery of this mechanism broadens our perspective on membrane fission by demonstrating how any protein, independent of its structure, can assist in this essential cellular process.
Identification of specific posttranslational
O
-mycoloylations mediating protein targeting to the mycomembrane
Authors: Carel Clément , Marcoux Julien , Réat Valérie , Parra Julien , Latgé Guillaume , Laval Françoise , Demange Pascal , Burlet-Schiltz Odile , Milon Alain , Daffé Mamadou , Tropis Maryelle G. , Renault Marie A. M.
Published: April 2017

Significance

Protein secretion is an essential determinant of bacterial physiology and virulence. Members of the Corynebacteriales order have evolved a complex cell envelope containing two membranes, a plasma membrane and an outer membrane, called the mycomembrane, which harbors mycolic acids and outer membrane proteins (OMPs) of unusual structure. Here, we have investigated the biogenesis of OMPs in
Corynebacterium glutamicum
and deciphered the role of
O
-mycoloylation in targeting OMPs to the mycomembrane. Partially enabled by our methodology, we found that the posttranslational state of major OMPs determined their presence in the outer membrane vs. the extracellular medium. We have also uncovered a short linear amino acid motif for
O
-acylation of proteins that seems to be preserved throughout the kingdoms.
Intracellular metabolite β-glucosylceramide is an endogenous Mincle ligand possessing immunostimulatory activity
Authors: Nagata Masahiro , Izumi Yoshihiro , Ishikawa Eri , Kiyotake Ryoko , Doi Rieko , Iwai Satoru , Omahdi Zakaria , Yamaji Toshiyuki , Miyamoto Tomofumi , Bamba Takeshi , Yamasaki Sho
Published: April 2017

Significance

Sensing tissue damage is a crucial function of pattern recognition receptors (PRRs). However, endogenous ligand recognition by PRRs is not well documented. Macrophage inducible C-type lectin (Mincle) is a PRR that recognizes both pathogens and damaged cells. In this study, we isolated endogenous glycolipids derived from damaged cells and identified a ubiquitous intracellular metabolite, β-glucosylceramide (GlcCer), as a Mincle ligand. β-GlcCer induced inflammatory and acquired immune responses via Mincle on myeloid cells. Accumulation of β-GlcCer leads to Gaucher disease, a disorder characterized mainly by systemic inflammation. In a Gaucher model in which mice are deficient in the β-GlcCer–degrading enzyme, further deletion of the Mincle gene attenuated inflammatory responses. These results suggest that β-GlcCer is an endogenous Mincle ligand and acts as an immunostimulatory factor upon cell damage.
Structure of arylO-demethylase offers molecular insight into a catalytic tyrosine-dependent mechanism
Authors: Kohler Amanda C. , Mills Matthew J. L. , Adams Paul D. , Simmons Blake A. , Sale Kenneth L.
Published: April 2017

Significance

Modern industrial and agricultural practices generate large quantities of aromatic pollutants; however, these waste products can be converted into fine chemicals, fuels, and plastics through biocatalytic pathways. The bacterial world can inform such utilization strategies as certain strains of soil and marine bacteria metabolize environmentally derived aromatics. Many of these metabolic pathways involve aryl intermediates that require demethylation to facilitate modification and ring opening for assimilation into the tricarboxylic acid (TCA) cycle. Aryl demethylases, which catalyze this reaction, are poorly understood, making their utilization in biotechnology difficult. We provide the structural and mechanistic characterization of a single-domain aryl demethylase, LigM, which employs a tyrosine-dependent mechanism. Insights from this work will inform synthetic biology approaches to convert underutilized aromatics into higher value compounds.
Direct visualization of the arterial wall water permeability barrier using CARS microscopy
Authors: Lucotte Bertrand M. , Powell Chloe , Knutson Jay R. , Combs Christian A. , Malide Daniela , Yu Zu-Xi , Knepper Mark , Patel Keval D. , Pielach Anna , Johnson Errin , Borysova Lyudmyla , Dora Kim A. , Balaban Robert S.
Published: April 2017

Significance

Low water permeability is critical to the pressurized blood conduit function of the artery. Arterial wall permeability is altered in diseases including diabetes and atherosclerosis, in acute shock, and with the aging process. Here we directly map the water permeability and the associated pressure profile across intact pressurized arteries with coherent anti-Stokes Raman scattering microscopy and D
2
O tracer experiments. We identify the endothelial basolateral membrane as the major barrier to water permeation. The advantageously positioned water barrier permits the direct transfer of arterial pressure to subendothelial elastic macromolecules. The mechanically sensitive endothelial cell is thus protected from static or pulsed-pressure–induced deformation. Disruption of this pressure transmission could contribute to endothelial dysfunction in various disease states.
Unveiling the carrier transport mechanism in epitaxial graphene for forming wafer-scale, single-domain graphene
Authors: Bae Sang-Hoon , Zhou Xiaodong , Kim Seyoung , Lee Yun Seog , Cruz Samuel S. , Kim Yunjo , Hannon James B. , Yang Yang , Sadana Devendra K. , Ross Frances M. , Park Hongsik , Kim Jeehwan
Published: April 2017

Significance

The use of epitaxial graphene has been less favored over the use of chemical vapor deposition (CVD)-grown polycrystalline graphene because graphene formed near SiC vicinal steps accompanies carrier scattering, which makes the practical domain size of epitaxial graphene much smaller than that of CVD-grown graphene. Nonetheless, the origin of carrier scattering at the SiC vicinal steps has not been fully understood. Here, we experimentally reveal that graphene formed at side walls is pristine, and the scattering near the steps mainly originates from the deformation of graphene and partially from stripes of bilayer graphene. This understanding of the origin of scattering allows us to demonstrate large-size single-domain graphene, removing major scattering sources through a layer-resolved transfer.
Emergence of a new
Neisseria meningitidis
clonal complex 11 lineage 11.2 clade as an effective urogenital pathogen
Authors: Tzeng Yih-Ling , Bazan Jose A. , Turner Abigail Norris , Wang Xin , Retchless Adam C. , Read Timothy D. , Toh Evelyn , Nelson David E. , Del Rio Carlos , Stephens David S.
Published: April 2017

Significance

Neisseria meningitidis
(Nm) remains a leading cause of meningitis and rapidly fatal sepsis in otherwise healthy individuals. Historically, Nm is not recognized as a significant cause of urogenital infections. Since 2015, a significant increase of meningococcal urethritis primarily among heterosexual men has been reported in multiple US cities. We defined that a unique nonencapsulated Nm clade, which belonged to the cc11/ET-15 hyperinvasive lineage, was linked to these Nm urethritis clusters. The clade isolates causing urethritis clusters in the United States may have adapted to the urogenital environment with two unique molecular fingerprints: the insertion of IS1301 with associated deletion of capsule, enhancing mucosal adherence, and the acquisition of the gonococcal denitrification pathway by gene conversion, promoting anaerobic growth.
Mass spectrometric identification of intermediates in the O
2
-driven [4Fe-4S] to [2Fe-2S] cluster conversion in FNR
Authors: Crack Jason C. , Thomson Andrew J. , Le Brun Nick E.
Published: April 2017

Significance

The transcriptional regulator Fumarate and Nitrate Reduction is the master switch for the transition between anaerobic and aerobic respiration in many other bacteria. It fulfills this role by controlling the expression of >300 genes in response to O
2
. It senses O
2
through a [4Fe-4S] cluster cofactor, which undergoes conversion to a [2Fe-2S] cluster on reaction with O
2
, leading to loss of DNA binding. By using time-resolved electrospray ionization mass spectrometry, we gained insight into the reaction through detection of cluster conversion intermediates and products, including a [3Fe-3S] cluster. The data also show that sulfide released from the cluster is oxidized during the conversion reaction and not after it. Our methodology has great potential for broad application to studies of cofactor reactivities.
Biosynthesis of the pyrrolidine protein synthesis inhibitor anisomycin involves novel gene ensemble and cryptic biosynthetic steps
Authors: Zheng Xiaoqing , Cheng Qiuxiang , Yao Fen , Wang Xiaozheng , Kong Lingxin , Cao Bo , Xu Min , Lin Shuangjun , Deng Zixin , Chooi Yit-Heng , You Delin
Published: April 2017

Significance

Despite significant advances in the prediction of natural product biosynthetic gene clusters (BGCs) from microbial genomes, challenges remain for those belong to the lesser-known classes. Using a bioactivity-guided library screening approach, we have identified a BGC encoding the biosynthesis of anisomycin, an important pyrrolidine-containing protein synthesis inhibitor. The biosynthetic pathway is distinct from known bacterial alkaloid pathways and involves a class of natural product backbone biosynthesis genes encoding an α-keto acid-incorporating transketolase. A cryptic but crucial glycosylation, unexpected transaminations, and a multistep pyrrolidine-forming reaction catalyzed by a single enzyme are also required to complete the assembly of the core benzylpyrrolidine scaffold. These findings open up new avenues for genomics-guided natural product discovery and engineering of pyrrolidine antibiotics.
Evidence of low-density and high-density liquid phases and isochore end point for water confined to carbon nanotube
Authors: Nomura Kentaro , Kaneko Toshihiro , Bai Jaeil , Francisco Joseph S. , Yasuoka Kenji , Zeng Xiao Cheng
Published: April 2017

Significance

Bulk water is known for its rich phase behavior, including 18 crystalline phases and 3 amorphous phases. Although computer simulations have uncovered coexistence of metastable low- and high-density liquid water below the freezing point, experimental evidence is still lacking because of the predicted coexistence below 230 K. Here, we show simulation evidence that, inside an isolated carbon nanotube with a diameter of 1.25 nm, both low- and high-density liquid water states can be detected near ambient temperature (278–292 K) and above ambient pressure. In the temperature–pressure phase diagram, the low- and high-density liquid phases are separated by hexagonal ice nanotube phase. The latter has already been observed in the laboratory.
The elaborate route for UDP-arabinose delivery into the Golgi of plants
Authors: Rautengarten Carsten , Birdseye Devon , Pattathil Sivakumar , McFarlane Heather E. , Saez-Aguayo Susana , Orellana Ariel , Persson Staffan , Hahn Michael G. , Scheller Henrik V. , Heazlewood Joshua L. , Ebert Berit
Published: April 2017

Significance

Nucleotide sugars, the activated sugar donors essential for processes such as cell wall biosynthesis and protein and lipid glycosylation are predominantly made in the cytosol. However, a highly diverse range of glycosyltransferases that are located within the Golgi lumen, mediate the above-mentioned glycosylation reactions. Thus, transport of nucleotide sugars across the Golgi membrane into the lumen is crucial for growth and development of many species including microorganisms, plants, and humans. In this study, we identify and functionally characterize four UDP-arabinofuranose transporters from
Arabidopsis
that are responsible for the delivery of activated arabinose, a critical sugar of plant cell walls, glycoproteins, and signaling peptides.