bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk‐based security assessment of transmission line overloading considering spatio‐temporal dependence of load and wind power using vine copula
Authors: Khuntia Swasti R. , Rueda Jose L. , van der Meijden Mart A.M.M.
Published: April 2019

Location of wind power plants and demand centres are not always close by; hence, the transmission of energy puts a burden on existing grid infrastructure. This unwanted burden necessitates transmission lines to operate more and more frequently close to their operating limits. To alleviate such situations, this research addresses the advantages of modelling spatio‐temporal dependence of load and wind power using vine copula. Probabilistic AC optimal power flow is performed on a modified IEEE 39‐bus system with significant wind penetration. Real load and wind power data from a U.S. utility is mapped onto the test‐case to achieve realistic results. Load flow calculation can help in performing steady‐state voltage and overload evaluations for post‐disturbance system conditions, because the security level of a power system is determined by the likelihood and severity of security violation. In this research, the probability of line overload is calculated from load flow and the severity function describes the risk of line overloading. Two case studies depicting future operating conditions of massive wind power penetration with reduced fossil fuel and nuclear power generation are considered. Simulation results prove the advantage of addressing spatio‐temporal dependency to quantify the overload risk index, which is treated as a security indicator.
Discrete wavelet transform based unsupervised underdetermined blind source separation methodology for radar pulse deinterleaving using antenna scan pattern
Authors: Dutt Rashi , Baloria Anuradha , Prasad V. Ram Chandra , ESMP Radhakrishna , Acharyya Amit
Published: April 2019

The authors propose a discrete wavelet transform‐based unsupervised underdetermined blind source separation methodology for radar pulse deinterleaving using a novel parameter, i.e. the radar antenna scan pattern. Deinterleaving becomes a challenging task in case of dense pulse scenario with parameter agile radars and the authors show that the scan pattern is an excellent parameter for this task. The results also indicate that the methodology is very suitable in case of jittered and staggered pulse repetition interval with reduced missing pulses and false alarm rate. Based on deinterleaved scan pattern information, a preliminary assessment of the number of emitters and their threat levels can be done.
Comparison of damping techniques for the soft‐stop of ultra‐fast linear actuators for HVDC breaker applications
Authors: Vilchis‐Rodriguez Damian S. , Shuttleworth Roger , Smith Alexander C. , Barnes Mike
Published: April 2019

This paper assesses the advantages, drawbacks, and overall suitability of different soft‐stop techniques to provide smooth deceleration of ultra‐fast linear actuators used in hybrid HVDC breaker designs, with the help of FEA simulations. The paper compares active and passive damping techniques in terms of efficacy, energy consumption, and interference with the ultra‐fast operation needed from the actuator. The possibility of combining active and passive damping techniques is discussed.
Electromagnetic performance with and without considering the impact of rotation on convective cooling
Authors: Chong Yew Chuan , Goss James , Popescu Mircea , Staton Dave , Hawkins Douglas , Boglietti Aldo
Published: April 2019

Accurate thermal modelling of electrical machines is important for electromagnetic performance determination of a design. This study presents the impact of rotation on convective cooling of a through‐ventilated motor – a design equivalent to the Tesla S 60 traction motor design. Machine temperatures after steady state with and without considering rotation effects are compared, and the influence on the machine continuous performance is investigated.
Fault blocking converters for HVDC transmission: a transient behaviour comparison
Authors: Vozikis Dimitrios , Rault Pierre , Holliday Derrick , Finney Stephen
Published: April 2019

A thorough comparison of the transient behaviours of two state‐of‐the‐art converters suitable for HVDC transmission is presented. The alternate arm and mixed‐cell modular multilevel converter topologies both have DC fault blocking capability and are selected for the comparison. Converter performance is evaluated and compared under various transient conditions including charging sequence, unbalanced operation, and DC fault recovery. The study is conducted using high‐fidelity converter simulation models, integrating detailed controllers that reflect real‐scale projects. The main findings of the study assist in the selection of the most suitable converter, given specific performance specifications such as capacitor voltage ripple, cell capacitor requirements, and response during transient operation.
Effect of high‐temperature AlN buffer on anisotropy of semi‐polar (11‐22) GaN with two pressure growth stages
Authors: Han Jun , Shi Fengfeng , Xing Yanhui , Wan Peiyuan , Gao Zhiyuan , Hu Xiaoling , Li Tao , Cao Shiwei , Zhang Yao
Published: April 2019

The low‐temperature GaN (LT‐GaN) and high‐temperature AlN (HT‐AlN) buffer layers were grown on m ‐plane sapphire by metal–organic chemical vapour deposition. The following semi‐polar (11‐22) GaN thin films were deposited under high‐ and low‐pressure growth stages. Anisotropy of (11‐22) GaN grown on HT‐AlN buffer along two in‐planar directions ([11‐2‐3] and [‐1100]) were clearly suppressed, the maximum variation of the X‐ray rocking curve full width at half maximum of (11‐22) GaN on LT‐GaN buffer was 0.2498°, that of (11‐22) GaN on HT‐AlN buffer was 0.0488°. The X‐ray diffraction results of on‐axis and off‐axis both indicated that the crystal quality of the epitaxial GaN layer with HT‐AlN buffer was obviously improved, and surface morphology was much smoother.
Synthesis of monodisperse Fe@SiO2 core‐shell nanocapsules and investigation of their magnetic behaviour
Authors: Zeng Wen , Yang Qiqi , Shao Bin , Guo Donglin , Li Chunhong , Ma Yilong , Yin Xueguo , Zhao Sibo , Li Kejian
Published: April 2019

The monodisperse Fe@SiO2 core‐shell nanocapsules were synthesised via hydrothermal reaction followed with heat treatment. Nanostructures were characterised by X‐ray diffraction, scanning electron microscopy and transmission electron microscopy. The magnetic properties of Fe@SiO2 nanocapsules were evaluated with magnetic property measurement system. The results show that Fe@SiO2 core‐shell nanocapsules are highly monodispersed. The silica thickness of Fe@SiO2 nanocapsules increased from 10–20 to 25–35 nm with increasing tetraethyl orthosilicate (TEOS) amount. In the Fe@SiO2 nanocapsules prepared with 900 μl TEOS, as the reaction temperature increases, the mean particle size of Fe@SiO2 nanocapsules increases from 328 to 546 nm. It is remarkable that the saturation magnetisation of Fe@SiO2 nanocapsules decreases with increasing silica thickness. However, the coercivity of nanocapsules has less influence with the variation of silica thickness and particles’ length.
How the power spectrum of dust continuum images may hide the presence of a characteristic filament width
Authors: Roy A. , André Ph. , Arzoumanian D. , Miville-Deschênes M.-A. , Könyves V. , Schneider N. , Pezzuto S. , Palmeirim P. , Kirk J. M.
Published: April 2019

Context. Herschel observations of interstellar clouds support a paradigm for star formation in which molecular filaments play a central role. One of the foundations of this paradigm is the finding, based on detailed studies of the transverse column density profiles observed with Herschel, that nearby molecular filaments share a common inner width of ∼0.1 pc. The existence of a characteristic filament width has been recently questioned, however, on the grounds that it seems inconsistent with the scale-free nature of the power spectrum of interstellar cloud images.

Aims. In an effort to clarify the origin of this apparent discrepancy, we examined the power spectra of the Herschel/SPIRE 250 μm images of the Polaris, Aquila, and Taurus–L1495 clouds in detail and performed a number of simple numerical experiments by injecting synthetic filaments in both the Herschel images and synthetic background images.

Methods. We constructed several populations of synthetic filaments of 0.1 pc width with realistic area filling factors (Afil) and distributions of column density contrasts (δc). After adding synthetic filaments to the original Herschel images, we recomputed the image power spectra and compared the results with the original, essentially scale-free power spectra. We used the χ2variance of the residuals between the best power-law fit and the output power spectrum in each simulation as a diagnostic of the presence (or absence) of a significant departure from a scale-free power spectrum.

Results. We find that χ2variance depends primarily on the combined parameter δ22 Afil. According to our numerical experiments, a significant departure from a scale-free behavior and thus the presence of a characteristic filament width become detectable in the power spectrum when δ22 Afil ⪆ 0.1 for synthetic filaments with Gaussian profiles and δ22 Afil ⪆ 0.4 for synthetic filaments with Plummer-like density profiles. Analysis of the real Herschel 250 μm data suggests that δ22 Afil is ∼0.01 in the case of the Polaris cloud and ∼0.016 in the Aquila cloud, significantly below the fiducial detection limit of δ22 Afil ∼ 0.1 in both cases. In both clouds, the observed filament contrasts and area filling factors are such that the filamentary structure contributes only ∼1/5 of the power in the image power spectrum at angular frequencies where an effect of the characteristic filament width is expected.

Conclusions. We conclude that the essentially scale-free power spectra of Herschel images remain consistent with the existence of a characteristic filament width ∼0.1 pc and do not invalidate the conclusions drawn from studies of the filament profiles.
Spectroscopic transit search: a self-calibrating method for detecting planets around bright stars
Authors: van Sluijs Lennart , de Mooij Ernst , Kenworthy Matthew , Celeste Maggie , Hooton Matthew J. , Mamajek Eric E. , Sipőcz Brigitta , Snellen Ignas. A. G. , Ridden-Harper Andrew R. , Wilson Paul A.
Published: April 2019

Aims. We aim to search for transiting exoplanets around the star β Pictoris using high-resolution spectroscopy and Doppler imaging that removes the need for standard star observations. These data were obtained on the VLT with UVES during the course of an observing campaign throughout 2017 that monitored the Hill sphere transit of the exoplanet β Pictoris b.

Methods. We utilized line profile tomography as a method for the discovery of transiting exoplanets. By measuring the exoplanet distortion of the stellar line profile, we removed the need for reference star measurements. We demonstrated the method with white noise simulations, and then looked at the case of β Pictoris, which is a δ Scuti pulsator. We describe a method to remove the stellar pulsations and perform a search for any transiting exoplanets in the resultant data set. We injected fake planet transits with varying orbital periods and planet radii into the spectra and determined the recovery fraction.

Results. In the photon noise limited case we can recover planets down to a Neptune radius with an ~80% success rate, using an 8 m telescope with a R ~ 100 000 spectrograph and 20 min of observations per night. The pulsations of β Pictoris limit our sensitivity to Jupiter-sized planets, but a pulsation removal algorithm improves this limit to Saturn-sized planets. We present two planet candidates, but argue that their signals are most likely caused by other phenomena.

Conclusions. We have demonstrated a method for searching for transiting exoplanets that (i) does not require ancillary calibration observations, (ii) can work on any star whose rotational broadening can be resolved with a high spectral dispersion spectrograph, and (iii) provides the lowest limits so far on the radii of transiting Jupiter-sized exoplanets around β Pictoris with orbital periods from 15 days to 200 days with >50% coverage.
Effects of Ultra-Low-Dose Aspirin in Thrombosis and Haemorrhage
Authors: Eizayaga Francisco Xavier , Belon Philippe , Desplat Vanessa , Aguejouf Omar , Doutremepuich Christian
Published: April 2019

Background Aspirin is the oldest and possibly the most widely used pharmacologically active substance still used in allopathic medicine. Its effect on fever and inflammation has paved the way to its anti-thrombotic effect. Dilutions of aspirin have been tested for many years in the University of Bordeaux, in humans as well as in animal models.

Methods This article is a review of the totality of articles published by the Laboratory of Hematology of the Faculty of Pharmacy of the University of Bordeaux, reporting different doses and dilutions of aspirin, different kinds of inhibitors, transgenic mice and animal models of disease such as portal hypertension and cirrhosis.

Results Homeopathic dilutions of aspirin, notably 15 cH, have shown a pro-thrombotic effect in humans and in in-vivo animal studies. Longitudinal studies in rats have also shown an initial anti-thrombotic effect followed by a pro-thrombotic effect of aspirin several days after a single high-dose administration. This pro-thrombotic effect seems to act by inhibiting the cyclooxygenase (COX)-2 pathway in studies performed with COX selective inhibitors and in knock-out mice without COX-1 or COX-2. This effect may explain the thrombo-embolic complications described after aspirin withdrawal for the purposes of surgery or after non-compliance with anti-platelet therapy, and it may be beneficial in normalising primary haemostasis and decreasing haemorrhage in animal models of portal hypertension and cirrhosis.

Conclusions Aspirin 15 cH acts through the inhibition of the COX-2 pathway producing a clear pro-thrombotic effect. Further studies should clarify if the pro-thrombotic effect of aspirin withdrawal and the effect of aspirin 15 cH are related, as secondary effects of the same drug. Clarifying this last outcome may be of great significance to public health.
Neutrophil and Monocyte Counts in Heparin-Induced Thrombocytopenia
Authors: Hui Madeleine , Sheppard Jo-Ann I. , Li Na , Warkentin Theodore E.
Published: April 2019

Background Heparin-induced thrombocytopenia (HIT) antibodies activate platelets, monocytes and neutrophils. Despite these findings, it is unknown whether white blood cell (WBC) counts, including neutrophils and monocytes, are altered during HIT.

Materials and Methods We evaluated changes in total WBC counts (including WBC subsets), in 50 post-cardiac surgery patients with serologically confirmed HIT (30 patients with HIT-associated thrombosis). Daily leukocyte counts were compared with those measured one day prior to HIT onset; WBC increases were classified as mild (20.0–49.9%), moderate (50.0–99.9%) or major (≥ 100% increase). We also compared changes in WBC counts in HIT patients with and without HIT-associated thrombosis, and non-HIT patients with thrombosis.

Results Most (34/50 [68.0%]) patients with HIT developed WBC count increases (mild, 35.3%; moderate, 44.1%; major, 20.6%). The peak WBC count occurred on day 4 (median) of HIT, which corresponded to day 10 (median) post-surgery. Absolute neutrophil counts increased in most patients (38/50 [76.0%]); whereas absolute monocyte counts rose in some patients, the overall tendency was for the monocyte count to decrease during HIT. Unexpectedly, we found that the increase in total WBC counts, as well as in neutrophils, was seen mainly in patients who developed HIT-associated or non-HIT-associated thrombosis; in contrast, no difference in monocyte levels was seen in patients with or without thrombosis.

Conclusion Leukocytosis and neutrophilia are commonly observed in patients with HIT, particularly in patients with HIT-associated thrombosis, as well as non-HIT patients with thrombosis. Thus, leukocytosis/neutrophilia should not infer automatically a diagnosis of infection or inflammation, when evaluating thrombocytopenia in heparin-exposed patients.
The Direct Thrombin Inhibitors Dabigatran and Lepirudin Inhibit GPIbα-Mediated Platelet Aggregation
Authors: Trabold Katharina , Makhoul Stephanie , Gambaryan Stepan , van Ryn Joanne , Walter Ulrich , Jurk Kerstin
Published: April 2019

The direct thrombin inhibitor (DTI) dabigatran is a non-vitamin K antagonist oral anticoagulant for the prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation. In addition to its anti-thrombotic efficacy, dabigatran has been suggested to exert some pro-thrombotic effect due to fostering the ligation of thrombin to its high affinity platelet receptor glycoprotein (GP) Ibα in patients with atrial fibrillation. On the other hand, we provided evidence that a member of another class of DTIs, lepirudin, stimulates the inhibitory cyclic guanosine monophosphate (cGMP)/soluble guanylate cyclase pathway in human platelets. Here, we investigated the effect of lepirudin and dabigatran spiked to platelets from healthy volunteers on GPIbα-mediated platelet aggregation and agglutination. Ristocetin/von Willebrand factor (vWF)-induced aggregation of platelets in the presence or absence of plasma was significantly inhibited by lepirudin, dabigatran and D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone (PPACK). However, ristocetin/vWF-mediated platelet agglutination and binding of vWF to platelets were not affected by the DTIs. The anti-aggregatory effect was confirmed by using the GPIbα-specific agonist echicetin beads for human and murine platelets. DTIs diminished echicetin beads-induced Syk Y352 phosphorylation (used here as readout for an early signal occurring during echicetin-induced platelet aggregation), but did not inhibit adenosine diphosphate- or thromboxane A2-induced platelet aggregation. Thrombin was not generated in response to ristocetin/vWF or echicetin beads and therefore did not explain the inhibitory effect of the DTIs. Therapeutic concentration of lepirudin and dabigatran did not affect significantly platelet vasodilator-stimulated phosphoprotein S239 phosphorylation or cGMP and cyclic adenosine monophosphate levels. These data suggest that the DTIs, lepirudin and dabigatran, impair platelet activation measured during platelet aggregation induced by ristocetin/vWF or echicetin beads.
Presence of Extended-Spectrum β-lactamase, CTX-M-65 in Salmonella enterica serovar Infantis Isolated from Children with Diarrhea in Lima, Peru
Authors: Granda Ana , Riveros Maribel , Martínez-Puchol Sandra , Ocampo Karen , Laureano-Adame Laura , Corujo Alfredo , Reyes Isabel , Ruiz Joaquim , Ochoa Theresa J.
Published: April 2019

Gastroenteritis in children is a serious condition in many parts of the world. Salmonella enterica is one of the causes of the disease. In this study, 280 fecal samples from children with diarrhea in four hospitals in Lima, Peru, were collected between September 2012 and March 2013. Salmonella was detected in 26 of the samples. Serotyping demonstrated that 25 of the isolates were S. enterica Infantis, and one isolate was S. enterica Typhimurium. Repetitive extragenic palindromic–polymerase chain reaction analysis suggests that all S. Infantis belong to the same clone. All but one of the S. Infantis isolates exhibited an extended-spectrum β-lactamase phenotype as they harbored bla
CTX-M 65. Two strains also carried bla
TEM-1. Nine of the isolates were resistant to azithromycin and two to ciprofloxacin. This study demonstrates that a multidrug-resistant S. Infantis clone carrying bla
CTX-M 65 was circulating among children in Lima, Peru. The development of molecular epidemiology studies in Salmonella-causing diarrhea or other pathologies in Lima and in other areas will be useful to determine the permanence, geographical spread, and clinical implications of this clone.
An Overview of Robotics in Functional Neurosurgery
Authors: Vazhayil Vikas , Rao Madhav , Beniwal Manish , Sadashiva Nishanth , Lakshmi Narasinga , Somanna Sampath
Published: April 2019

Stereotactic techniques are used in a wide range of neurosurgical procedures. The procedures demand a high degree of spatial accuracy and minimal error. There are diverse functional surgeries that require stereotactic procedures, including deep brain stimulation, brain biopsies, and epilepsy procedures. Though the disease processes are diverse, all these procedures require accurate targeting of deep structures without visual guidance. The use of robots for stereotactic procedures is a natural progression in the surgeon's quest for higher accuracy and lower complications. This paper reviews the role of robots in stereotactic procedures and outlines current status of robots in stereotactic procedures. The shortcomings of current systems and an outline of an ideal stereotactic device are presented.
Small oscillations of non-dissipative Lagrangian systems
Authors: Massa Enrico , Vignolo Stefano
Published: April 2019

The small oscillations of an arbitrary scleronomous system subject to time-independent nondissipative forces are discussed. The linearized equations of motion are solved by quadratures. As in the conservative case, the general integral is shown to consist of a superposition of harmonic oscillations. A complexification of the resolving algorithm is presented.
Thermal characterization of thin films via dynamic infrared thermography
Authors: Greppmair Anton , Galfe Natalie , Amend Katharina , Stutzmann Martin , Brandt Martin S.
Published: April 2019

We extend the infrared thermography of thin materials for measurements of the full time response to homogeneous heating via illumination. We demonstrate that the thermal conductivity, the heat capacity, as well as the thermal diffusivity can be determined comparing the experimental data to finite difference simulations using a variety of test materials such as thin doped and undoped silicon wafers, sheets of steel, as well as gold and polymer films. We show how radiative cooling during calibration and measurement can be accounted for and that the effective emissivity of the material investigated can also be measured by the setup developed.
Quantum semigroups from synchronous games
Authors: Sołtan P. M.
Published: April 2019

We show that the C*-algebras associated with synchronous games give rise to certain quantum families of maps between the input and output sets of the game. In particular situations (e.g., for graph endomorphism games), these quantum families have a natural quantum semigroup structure, and if the condition of preservation of a natural state is added, they are in fact compact quantum groups.
Unifying obstacle detection, recognition, and fusion based on millimeter wave radar and RGB-depth sensors for the visually impaired
Authors: Long Ningbo , Wang Kaiwei , Cheng Ruiqi , Hu Weijian , Yang Kailun
Published: April 2019

It is very difficult for visually impaired people to perceive and avoid obstacles at a distance. To address this problem, the unified framework of multiple target detection, recognition, and fusion is proposed based on the sensor fusion system comprising a low-power millimeter wave (MMW) radar and an RGB-Depth (RGB-D) sensor. In this paper, the Mask R-CNN and the single shot multibox detector network are utilized to detect and recognize the objects from color images. The obstacles’ depth information is obtained from the depth images using the MeanShift algorithm. The position and velocity information on the multiple target is detected by the MMW radar based on the principle of a frequency modulated continuous wave. The data fusion based on the particle filter obtains more accurate state estimation and richer information by fusing the detection results from the color images, depth images, and radar data compared with using only one sensor. The experimental results show that the data fusion enriches the detection results. Meanwhile, the effective detection range is expanded compared to using only the RGB-D sensor. Moreover, the data fusion results keep high accuracy and stability under diverse range and illumination conditions. As a wearable system, the sensor fusion system has the characteristics of versatility, portability, and cost-effectiveness.
Visual attention is not limited to the oculomotor range
Authors: Hanning Nina M. , Szinte Martin , Deubel Heiner
Published: April 2019

Both patients with eye movement disorders and healthy participants whose oculomotor range had been experimentally reduced have been reported to show attentional deficits at locations unreachable by their eyes. Whereas previous studies were mainly based on the evaluation of reaction times, we measured visual sensitivity before saccadic eye movements and during fixation at locations either within or beyond participants’ oculomotor range. Participants rotated their heads to prevent them from performing large rightward saccades. In this posture, an attentional cue was presented inside or outside their oculomotor range. Participants either made a saccade to the cue or maintained fixation while they discriminated the orientation of a visual noise patch. In contrast to previous reports, we found that the cue attracted visual attention regardless of whether it was presented within or beyond participants’ oculomotor range during both fixation and saccade preparation. Moreover, when participants aimed to look to a cue that they could not reach with their eyes, we observed no benefit at their actual saccade endpoint. This demonstrates that spatial attention is not coupled to the executed oculomotor program but instead can be deployed unrestrictedly also toward locations to which no saccade can be executed. Our results are compatible with the view that covert and overt attentional orienting are guided by feedback projections of visual and visuomotor neurons of the gaze control system, irrespective of oculomotor limitations.
Data gaps and opportunities for comparative and conservation biology
Authors: Conde Dalia A. , Staerk Johanna , Colchero Fernando , da Silva Rita , Schöley Jonas , Baden H. Maria , Jouvet Lionel , Fa Julia E. , Syed Hassan , Jongejans Eelke , Meiri Shai , Gaillard Jean-Michel , Chamberlain Scott , Wilcken Jonathan , Jones Owen R. , Dahlgren Johan P. , Steiner Ulrich K. , Bland Lucie M. , Gomez-Mestre Ivan , Lebreton Jean-Dominique , González Vargas Jaime , Flesness Nate , Canudas-Romo Vladimir , Salguero-Gómez Roberto , Byers Onnie , Berg Thomas Bjørneboe , Scheuerlein Alexander , Devillard Sébastien , Schigel Dmitry S. , Ryder Oliver A. , Possingham Hugh P. , Baudisch Annette , Vaupel James W.
Published: April 2019

Biodiversity loss is a major challenge. Over the past century, the average rate of vertebrate extinction has been about 100-fold higher than the estimated background rate and population declines continue to increase globally. Birth and death rates determine the pace of population increase or decline, thus driving the expansion or extinction of a species. Design of species conservation policies hence depends on demographic data (e.g., for extinction risk assessments or estimation of harvesting quotas). However, an overview of the accessible data, even for better known taxa, is lacking. Here, we present the Demographic Species Knowledge Index, which classifies the available information for 32,144 (97%) of extant described mammals, birds, reptiles, and amphibians. We show that only 1.3% of the tetrapod species have comprehensive information on birth and death rates. We found no demographic measures, not even crude ones such as maximum life span or typical litter/clutch size, for 65% of threatened tetrapods. More field studies are needed; however, some progress can be made by digitalizing existing knowledge, by imputing data from related species with similar life histories, and by using information from captive populations. We show that data from zoos and aquariums in the Species360 network can significantly improve knowledge for an almost eightfold gain. Assessing the landscape of limited demographic knowledge is essential to prioritize ways to fill data gaps. Such information is urgently needed to implement management strategies to conserve at-risk taxa and to discover new unifying concepts and evolutionary relationships across thousands of tetrapod species.
MAPK pathway and B cells overactivation in multiple sclerosis revealed by phosphoproteomics and genomic analysis
Authors: Kotelnikova Ekaterina , Kiani Narsis A. , Messinis Dimitris , Pertsovskaya Inna , Pliaka Vicky , Bernardo-Faura Marti , Rinas Melanie , Vila Gemma , Zubizarreta Irati , Pulido-Valdeolivas Irene , Sakellaropoulos Theodore , Faigle Wolfgang , Silberberg Gilad , Masso Mar , Stridh Pernilla , Behrens Janina , Olsson Tomas , Martin Roland , Paul Friedemann , Alexopoulos Leonidas G. , Saez-Rodriguez Julio , Tegner Jesper , Villoslada Pablo
Published: April 2019

Dysregulation of signaling pathways in multiple sclerosis (MS) can be analyzed by phosphoproteomics in peripheral blood mononuclear cells (PBMCs). We performed in vitro kinetic assays on PBMCs in 195 MS patients and 60 matched controls and quantified the phosphorylation of 17 kinases using xMAP assays. Phosphoprotein levels were tested for association with genetic susceptibility by typing 112 single-nucleotide polymorphisms (SNPs) associated with MS susceptibility. We found increased phosphorylation of MP2K1 in MS patients relative to the controls. Moreover, we identified one SNP located in the PHDGH gene and another on IRF8 gene that were associated with MP2K1 phosphorylation levels, providing a first clue on how this MS risk gene may act. The analyses in patients treated with disease-modifying drugs identified the phosphorylation of each receptor’s downstream kinases. Finally, using flow cytometry, we detected in MS patients increased STAT1, STAT3, TF65, and HSPB1 phosphorylation in CD19
+
cells. These findings indicate the activation of cell survival and proliferation (MAPK), and proinflammatory (STAT) pathways in the immune cells of MS patients, primarily in B cells. The changes in the activation of these kinases suggest that these pathways may represent therapeutic targets for modulation by kinase inhibitors.
Unifying photocycle model for light adaptation and temporal evolution of cation conductance in channelrhodopsin-2
Authors: Kuhne Jens , Vierock Johannes , Tennigkeit Stefan Alexander , Dreier Max-Aylmer , Wietek Jonas , Petersen Dennis , Gavriljuk Konstantin , El-Mashtoly Samir F. , Hegemann Peter , Gerwert Klaus
Published: April 2019

Significance

Understanding the mechanisms of photoactivated biological processes facilitates the development of new molecular tools, engineered for specific optogenetic applications, allowing the control of neuronal activity with light. Here, we use a variety of experimental and theoretical techniques to examine the precise nature of the light-activated ion channel in one of the most important molecular species used in optogenetics, channelrhodopsin-2. Existing models for the photochemical and photophysical pathway after light absorption by the molecule fail to explain many aspects of its observed behavior, including the inactivation of the photocurrent under continuous illumination. We resolve this by proposing a branched photocycle explaining electrical and photochemical channel properties and establishing the structure of intermediates during channel turnover.
Sideways and stable crack propagation in a silicone elastomer
Authors: Lee Seunghyun , Pharr Matt
Published: April 2019

Significance

Soft materials exhibit fundamentally different fracture characteristics from other materials, and as such represent an open and fascinating research area. Herein, we have discovered a form of fracture in soft elastomers that we call “sideways cracking” in which cracks propagate perpendicular to their “standard” trajectory. These sideways cracks stably arrest, thereby allowing the material ahead of the crack to continue to sustain large loads. As such, understanding this phenomenon may enable the engineering of highly robust and stretchable materials. To explain this behavior, we perform mechanics-based analyses and substantiate a hypothesis that this behavior stems from structural rearrangement of polymer chains during stretching. Overall, this paper provides fundamental mechanical insight into basic phenomena associated with fracture of elastomers.
α-Sheet secondary structure in amyloid β-peptide drives aggregation and toxicity in Alzheimer’s disease
Authors: Shea Dylan , Hsu Cheng-Chieh , Bi Timothy M. , Paranjapye Natasha , Childers Matthew Carter , Cochran Joshua , Tomberlin Colson P. , Wang Libo , Paris Daniel , Zonderman Jeffrey , Varani Gabriele , Link Christopher D. , Mullan Mike , Daggett Valerie
Published: April 2019

Alzheimer’s disease (AD) is characterized by the deposition of β-sheet–rich, insoluble amyloid β-peptide (Aβ) plaques; however, plaque burden is not correlated with cognitive impairment in AD patients; instead, it is correlated with the presence of toxic soluble oligomers. Here, we show, by a variety of different techniques, that these Aβ oligomers adopt a nonstandard secondary structure, termed “α-sheet.” These oligomers form in the lag phase of aggregation, when Aβ-associated cytotoxicity peaks, en route to forming nontoxic β-sheet fibrils. De novo-designed α-sheet peptides specifically and tightly bind the toxic oligomers over monomeric and fibrillar forms of Aβ, leading to inhibition of aggregation in vitro and neurotoxicity in neuroblastoma cells. Based on this specific binding, a soluble oligomer-binding assay (SOBA) was developed as an indirect probe of α-sheet content. Combined SOBA and toxicity experiments demonstrate a strong correlation between α-sheet content and toxicity. The designed α-sheet peptides are also active in vivo where they inhibit Aβ-induced paralysis in a transgenic AβCaenorhabditis elegansmodel and specifically target and clear soluble, toxic oligomers in a transgenic APPsw mouse model. The α-sheet hypothesis has profound implications for further understanding the mechanism behind AD pathogenesis.
Cortical patterning of abnormal morphometric similarity in psychosis is associated with brain expression of schizophrenia-related genes
Authors: Morgan Sarah E. , Seidlitz Jakob , Whitaker Kirstie J. , Romero-Garcia Rafael , Clifton Nicholas E. , Scarpazza Cristina , van Amelsvoort Therese , Marcelis Machteld , van Os Jim , Donohoe Gary , Mothersill David , Corvin Aiden , Pocklington Andrew , Raznahan Armin , McGuire Philip , Vértes Petra E. , Bullmore Edward T.
Published: April 2019

Schizophrenia has been conceived as a disorder of brain connectivity, but it is unclear how this network phenotype is related to the underlying genetics. We used morphometric similarity analysis of MRI data as a marker of interareal cortical connectivity in three prior case–control studies of psychosis: in total,
n
= 185 cases and
n
= 227 controls. Psychosis was associated with globally reduced morphometric similarity in all three studies. There was also a replicable pattern of case–control differences in regional morphometric similarity, which was significantly reduced in patients in frontal and temporal cortical areas but increased in parietal cortex. Using prior brain-wide gene expression data, we found that the cortical map of case–control differences in morphometric similarity was spatially correlated with cortical expression of a weighted combination of genes enriched for neurobiologically relevant ontology terms and pathways. In addition, genes that were normally overexpressed in cortical areas with reduced morphometric similarity were significantly up-regulated in three prior post mortem studies of schizophrenia. We propose that this combined analysis of neuroimaging and transcriptional data provides insight into how previously implicated genes and proteins as well as a number of unreported genes in their topological vicinity on the protein interaction network may drive structural brain network changes mediating the genetic risk of schizophrenia.
Large bandgap of pressurized trilayer graphene
Authors: Ke Feng , Chen Yabin , Yin Ketao , Yan Jiejuan , Zhang Hengzhong , Liu Zhenxian , Tse John S. , Wu Junqiao , Mao Ho-kwang , Chen Bin
Published: April 2019

Significance

The remarkable physical properties of graphene make it a marvel of materials science. However, the gapless character of graphene makes it impossible to be a strong contender for postsilicon electronics. Opening a sizable bandgap in graphene is hence highly desired. We developed a microwiring technique for high-pressure electrical measurement on nanomaterials with only a few layers. Through in situ electrical and absorption studies we demonstrate that an intrinsic bandgap of 2.5 eV is achievable in compressed Bernal-stacked trilayer graphene. The realization of a wide bandgap in compressed graphene stimulates explorations for the practical application of carbon-based electronic devices.
Three-dimensional architecture of epithelial primary cilia
Authors: Sun Shufeng , Fisher Rebecca L. , Bowser Samuel S. , Pentecost Brian T. , Sui Haixin
Published: April 2019

We report a complete 3D structural model of typical epithelial primary cilia based on structural maps of full-length primary cilia obtained by serial section electron tomography. Our data demonstrate the architecture of primary cilia differs extensively from the commonly acknowledged 9+0 paradigm. The axoneme structure is relatively stable but gradually evolves from base to tip with a decreasing number of microtubule complexes (MtCs) and a reducing diameter. The axonemal MtCs are cross-linked by previously unrecognized fibrous protein networks. Such an architecture explains why primary cilia can elastically withstand liquid flow for mechanosensing. The nine axonemal MtCs in a cilium are found to differ significantly in length indicating intraflagellar transport processes in primary cilia may be more complicated than that reported for motile cilia. The 3D maps of microtubule doublet–singlet transitions generally display longitudinal gaps at the inner junction between the A- and B-tubules, which indicates the inner junction protein is a major player in doublet–singlet transitions. In addition, vesicles releasing from kidney primary cilia were observed in the structural maps, supporting that ciliary vesicles budding may serve as ectosomes for cell–cell communication.
Alarmone Ap4A is elevated by aminoglycoside antibiotics and enhances their bactericidal activity
Authors: Ji Xia , Zou Jin , Peng Haibo , Stolle Anne-Sophie , Xie Ruiqiang , Zhang Hongjie , Peng Bo , Mekalanos John J. , Zheng Jun
Published: April 2019

Significance

This paper demonstrates that aminoglycoside antibiotics induce the production of the Ap4A in bacteria. Increased intracellular Ap4A, in turn, promotes bacterial cell killing by this class of antibiotics, which correlated well with elevated damage to the bacterial membrane upon aminoglycoside treatment. These findings reveal a striking connection between aminoglycoside killing and the Ap4A production particularly under conditions of oxidative stress. Importantly, the results of this study suggest that targeting Ap4A degradation or inducing its hypersynthesis during therapy with aminoglycosides might help solve the well-known toxicity issue associated with this class of antibiotics by reducing the level of drug needed for effective treatment.
Hydrogen bonding steers the product selectivity of electrocatalytic CO reduction
Authors: Li Jingyi , Li Xiang , Gunathunge Charuni M. , Waegele Matthias M.
Published: April 2019

Significance

Many technologically interesting electrocatalytic reactions lead to a variety of products; that is, they exhibit poor product selectivity. Examples include the oxidations of ammonia and methane and the reductions of nitrogen and carbon dioxide. The poor selectivity hinders the adoption of these promising technologies. Improving the selectivity requires a molecular-level understanding of the factors that control these reaction processes. Herein, we investigated how the liquid reaction environment impacts the selectivity of the reduction of CO to ethylene, a prototypical process for multielectron–proton transfer reactions. We show that the intermolecular interaction between surface-adsorbed CO and interfacial water is critical for the formation of ethylene. This mechanistic insight is expected to guide the design of electrocatalytic interfaces with high product selectivity.
Delta-secretase-cleaved Tau antagonizes TrkB neurotrophic signalings, mediating Alzheimer’s disease pathologies
Authors: Xiang Jie , Wang Zhi-Hao , Ahn Eun Hee , Liu Xia , Yu Shan-Ping , Manfredsson Fredric P. , Sandoval Ivette M. , Ju Gong , Wu Shengxi , Ye Keqiang
Published: April 2019

Significance

BDNF is important in neuronal survival and synaptic plasticity. BDNF level reduction in Alzheimer’s disease (AD) is well documented, but it remains unclear whether BDNF deficiency contributes to AD pathology. We show that BDNF deprivation provokes asparagine endopeptidase (AEP) activation via reducing δ-secretase (AEP) T322 phosphorylation by Akt and subsequently cleaves Tau at N368 residue and enhances its binding with TrkB receptors, blocking the neurotrophic signals. Our data demonstrate that AEP-cleaved Tau N368 interacting with TrkB might account for BDNF reduction-triggered AD pathologies.
Expeditious, scalable solution growth of metal oxide films by combustion blade coating for flexible electronics
Authors: Wang Binghao , Guo Peijun , Zeng Li , Yu Xia , Sil Aritra , Huang Wei , Leonardi Matthew J. , Zhang Xinan , Wang Gang , Lu Shaofeng , Chen Zhihua , Bedzyk Michael J. , Schaller Richard D. , Marks Tobin J. , Facchetti Antonio
Published: April 2019

Significance

Solution-processing metal oxide (MO) films at low temperature enables their integration in mechanically flexible and inexpensive substrates for unconventional optoelectronics. However, temperature reduction has not been accompanied by a corresponding reduction in film-processing time, which remains far greater than acceptable for efficient/continuous additive manufacturing as in typical fabrication lines. Here, we report a highly efficient cofuel-assisted combustion process, which involves introducing both a fluorinated fuel and a preannealing step, that achieves ultrafast reaction and metal–oxygen–metal (M-O-M) lattice condensation within 10–60 s for several MO semiconductors and aluminum oxide dielectric. The resulting MO transistors exhibit high carrier mobility, excellent bias stability, and good flexibility.
An Ontological Justification for Contextual Authenticity
Authors: Moruzzi Caterina
Published: April 2019

In this paper I defend a contextualist interpretation of authenticity in musical performance: we judge a performance as authentic not in respect of a stable set of requirements but according to contextually determined factors. This solution is the natural outcome of an independently supported ontological account of musical works: Musical Stage Theory. The aim of the paper is to give new momentum to the debate concerning the notion of authenticity and to challenge a monistic interpretation of authenticity: there is not one authenticity but many.
Autochthony and space in communal war: Citizenship, conflicts, and infrastructure provision in Jos, Central Nigeria
Authors: Nnabuihe Onyekachi E
Published: April 2019

Since the 1990s, there has been an upsurge in conflicts of autochthony in several parts of the world. Autochthony invokes a sense of a politics of belonging and an attachment to the land. In Nigeria, the phenomenon raises questions of citizenship and can reinforce exclusionary practices which in turn provoke widespread violence between different Nigerian populations. Infrastructure provision in a communal conflict environment is a critical element of autochthony struggle, which has yet to be fully explored. Relying on archival sources, focus group discussions, interviews and observation, this article interrogates how the interactions between autochthony and space stimulates communal conflicts and affect infrastructure provision in Jos, Nigeria. The article focuses on how the ‘Black September’ incident in 2001 and its aftermath in Jos has defined citizenship. It argues that the politics of belonging is embedded in infrastructure provision, and understanding this relationship is crucial to understanding and addressing the conflicts in Jos and beyond.
Feasibility and Determinants of Orthostatic Hypotension Self-measurement at Home in an Elderly Community-Dwelling Population
Authors: Cohen Adrien , Vidal Jean-Sébastien , Roca Frédéric , Rananja Hanta , Hernandorena Intza , Coude du Foresto Laurent , Seux Marie-Laure , Rigaud Anne-Sophie , Hanon Olivier , Duron Emmanuelle
Published: April 2019

BACKGROUND

Orthostatic hypotension (OH) measurement reproducibility is poor. Our objectives were to assess feasibility of self-detection home-measured OH (HOH) and HOH determinants.

METHODS

Subjects older than 65 years, attending a geriatric outpatient clinic, able to understand the HOH protocol: 3 blood pressure (BP) measures after 5 minutes of seating and BP measures after 1 and 3 minutes of standing, each morning and evening for 3 consecutive days were lent a validated digital automatic sphygmomanometer. Reports containing at least 4 correct measurements were deemed a success. Factors associated with HOH were studied.

RESULTS

HOH feasibility was 82.8% (241 subjects) with no difference between participants who failed or succeeded. Among the 241 subjects (mean age (SD) = 78.0 (8.3) years old; 62.1% of women), 139 were free of HOH, 70 had 1 HOH episode and 32 had 2 or more HOH episodes. Hypertension, dementia, atrial fibrillation, diabetes, and heart failure were found in 70.0%, 10.4%, 9.4%, 8.8%, and 3.4% of cases, respectively. Subjects were treated with antihypertensive, benzodiazepine, statin medication in 47.3%, 9.3%, 7.4% of cases, respectively, and 42.4% experienced polypharmacy. HOH episodes were associated with dementia (P = 0.01), presence of OH during the geriatric outpatient clinic assessment (P = 0.0002), statin therapy (P = 0.04), and polypharmacy (P = 0.0002). In multivariate analysis, benzodiazepine (OR (95% CI) = 2.59 (1.10–6.08) and statin medication (OR (95% CI) = 1.92 (1.10–3.33)) remained significantly associated with HOH.

CONCLUSIONS

HOH had a good feasibility and relevant determinants. A study to address the predictive value of HOH will be conducted.
icHET: interactive visualization of cytoplasmic heteroplasmy
Authors: Phan Vinhthuy , Pham Diem-Trang , Melton Caroline , Ramsey Adam J , Daigle Bernie J , Mandel Jennifer R
Published: April 2019

Although heteroplasmy has been studied extensively in animal systems, there is a lack of tools for analyzing, exploring and visualizing heteroplasmy at the genome-wide level in other taxonomic systems. We introduce icHET, which is a computational workflow that produces an interactive visualization that facilitates the exploration, analysis and discovery of heteroplasmy across multiple genomic samples. icHET works on short reads from multiple samples from any organism with an organellar reference genome (mitochondrial or plastid) and a nuclear reference genome.

Availability and implementation

The software is available at https://github.com/vtphan/HeteroplasmyWorkflow.

Supplementary information

Supplementary data are available at Bioinformatics online.