bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of low‐ and ultralow‐dose computed tomography protocols for quantitative lung and airway assessment
Authors: Hammond Emily , Sloan Chelsea , Newell John D. , Sieren Jered P. , Saylor Melissa , Vidal Craig , Hogue Shayna , De Stefano Frank , Sieren Alexa , Hoffman Eric A. , Sieren Jessica C.
Published: June 2017

Purpose

Quantitative computed tomography (CT) measures are increasingly being developed and used to characterize lung disease. With recent advances in CT technologies, we sought to evaluate the quantitative accuracy of lung imaging at low‐ and ultralow‐radiation doses with the use of iterative reconstruction (IR), tube current modulation (TCM), and spectral shaping.

Methods

We investigated the effect of five independent CT protocols reconstructed with IR on quantitative airway measures and global lung measures using an in vivo large animal model as a human subject surrogate. A control protocol was chosen (NIH‐SPIROMICS + TCM) and five independent protocols investigating TCM, low‐ and ultralow‐radiation dose, and spectral shaping. For all scans, quantitative global parenchymal measurements (mean, median and standard deviation of the parenchymal HU, along with measures of emphysema) and global airway measurements (number of segmented airways and pi10) were generated. In addition, selected individual airway measurements (minor and major inner diameter, wall thickness, inner and outer area, inner and outer perimeter, wall area fraction, and inner equivalent circle diameter) were evaluated. Comparisons were made between control and target protocols using difference and repeatability measures.

Results

Estimated CT volume dose index (CTDIvol) across all protocols ranged from 7.32 mGy to 0.32 mGy. Low‐ and ultralow‐dose protocols required more manual editing and resolved fewer airway branches; yet, comparable pi10 whole lung measures were observed across all protocols. Similar trends in acquired parenchymal and airway measurements were observed across all protocols, with increased measurement differences using the ultralow‐dose protocols. However, for small airways (1.9 ± 0.2 mm) and medium airways (5.7 ± 0.4 mm), the measurement differences across all protocols were comparable to the control protocol repeatability across breath holds. Diameters, wall thickness, wall area fraction, and equivalent diameter had smaller measurement differences than area and perimeter measurements.

Conclusions

In conclusion, the use of IR with low‐ and ultralow‐dose CT protocols with CT volume dose indices down to 0.32 mGy maintains selected quantitative parenchymal and airway measurements relevant to pulmonary disease characterization.
Automatic renal segmentation for MR urography using 3D‐GrabCut and random forests
Authors: Yoruk Umit , Hargreaves Brian A. , Vasanawala Shreyas S.
Published: June 2017

Purpose

To introduce and evaluate a fully automated renal segmentation technique for glomerular filtration rate (GFR) assessment in children.

Methods

An image segmentation method based on iterative graph cuts (GrabCut) was modified to work on time‐resolved 3D dynamic contrast‐enhanced MRI data sets. A random forest classifier was trained to further segment the renal tissue into cortex, medulla, and the collecting system. The algorithm was tested on 26 subjects and the segmentation results were compared to the manually drawn segmentation maps using the F1‐score metric. A two‐compartment model was used to estimate the GFR of each subject using both automatically and manually generated segmentation maps.

Results

Segmentation maps generated automatically showed high similarity to the manually drawn maps for the whole‐kidney (F1 = 0.93) and renal cortex (F1 = 0.86). GFR estimations using whole‐kidney segmentation maps from the automatic method were highly correlated (Spearman's ρ = 0.99) to the GFR values obtained from manual maps. The mean GFR estimation error of the automatic method was 2.98 ± 0.66% with an average segmentation time of 45 s per patient.

Conclusion

The automatic segmentation method performs as well as the manual segmentation for GFR estimation and reduces the segmentation time from several hours to 45 s. Magn Reson Med 79:1696–1707, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Multi‐gradient‐echo myelin water fraction imaging: Comparison to the multi‐echo‐spin‐echo technique
Authors: Alonso‐Ortiz Eva , Levesque Ives R. , Pike G. Bruce
Published: June 2017

Purpose

Myelin water fraction (MWF) mapping based on multi‐gradient recalled‐echo (MGRE) imaging has been proposed as an alternative to the conventional multi‐echo‐spin‐echo (MESE) approach. In this work, we performed a comparative study of MESE and MGRE‐derived MWFs in the same subject group.

Methods

MESE and MGRE data were acquired in 12 healthy volunteers at 3T.
decay curves were corrected for the effects of field inhomogeneities and multicomponent analysis of
and
signals was performed using non‐negative least‐squares fitting.

Results

When comparing MGRE and MESE‐MWFs across volunteers, no significant differences were observed between average values in WM, deep GM (dGM), and cortical GM (cGM) that were (14 ± 3%), (6 ± 2%), and (8 ± 2%) for MGRE, and (13 ± 2%), (6 ± 1%), and (7 ± 1%), respectively, for MESE. The MGRE and MESE‐MWFs showed a strong correlation (r2 = 0.84) and Bland‐Altman analysis revealed a small positive bias of (0.8 ± 1.6%) (absolute difference) for the MGRE‐MWF.

Conclusion

Overall, we observed excellent agreement between the two techniques. The small positive bias of the MGRE‐MWF is thought to be a consequence of its potentially reduced sensitivity to water exchange effects, compared to the MESE‐MWF. This work suggests that with careful correction for the effects of field inhomogeneities, MGRE‐MWF imaging is a promising alternative to the MESE approach. Magn Reson Med 79:1439–1446, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Self‐reinforced polypropylene composites based on low‐cost commercial woven and non‐woven fabrics
Authors: Mijares José Luis , Agaliotis Eliana , Bernal Celina R. , Mollo Mariana
Published: June 2017

In the present paper, different self‐reinforced polypropylene (PP) composites based on low‐cost commercial woven (w) and non‐woven (nw) fabrics were obtained. Hot compaction (HC) and film stacking (FS) followed by compression molding were used to prepared the composites. The fracture and failure behavior of the different materials was determined under different testing conditions through quasi‐static uniaxial tensile tests, Izod impact experiments and by means of fracture mechanics tests on mode I double‐edge deeply notched tensile specimens. In the case of the composite obtained by film stacking + compression molding (rPP/nw/w‐FS) and the hot‐compacted composite (nw/w‐HC) containing simultaneously woven and non‐woven fabrics, the acoustic emission technique was applied in situ in the tensile tests to determine their consolidation quality and to identify the failure mechanisms responsible for their fracture behavior. It was observed that both composites exhibited relatively similar high consolidation quality. However, the hot‐compacted composite presented a more uniform distribution of failure mechanisms (debonding and fiber fracture) than the film‐stacked composite. The hot‐compacted composite containing both types of reinforcements exhibited the best combination of mechanical (tensile, impact, and fracture) properties. Therefore, this composite appeared as the most promising for structural applications among the different composites investigated.
WALK‐MAN: A High‐Performance Humanoid Platform for Realistic Environments
Authors: Tsagarakis N. G. , Caldwell D. G. , Negrello F. , Choi W. , Baccelliere L. , Loc V.G. , Noorden J. , Muratore L. , Margan A. , Cardellino A. , Natale L. , Mingo Hoffman E. , Dallali H. , Kashiri N. , Malzahn J. , Lee J. , Kryczka P. , Kanoulas D. , Garabini M. , Catalano M. , Ferrati M. , Varricchio V. , Pallottino L. , Pavan C. , Bicchi A. , Settimi A. , Rocchi A. , Ajoudani A.
Published: June 2017

In this work, we present WALK‐MAN, a humanoid platform that has been developed to operate in realistic unstructured environment, and demonstrate new skills including powerful manipulation, robust balanced locomotion, high‐strength capabilities, and physical sturdiness. To enable these capabilities, WALK‐MAN design and actuation are based on the most recent advancements of series elastic actuator drives with unique performance features that differentiate the robot from previous state‐of‐the‐art compliant actuated robots. Physical interaction performance is benefited by both active and passive adaptation, thanks to WALK‐MAN actuation that combines customized high‐performance modules with tuned torque/velocity curves and transmission elasticity for high‐speed adaptation response and motion reactions to disturbances. WALK‐MAN design also includes innovative design optimization features that consider the selection of kinematic structure and the placement of the actuators with the body structure to maximize the robot performance. Physical robustness is ensured with the integration of elastic transmission, proprioceptive sensing, and control. The WALK‐MAN hardware was designed and built in 11 months, and the prototype of the robot was ready four months before DARPA Robotics Challenge (DRC) Finals. The motion generation of WALK‐MAN is based on the unified motion‐generation framework of whole‐body locomotion and manipulation (termed loco‐manipulation). WALK‐MAN is able to execute simple loco‐manipulation behaviors synthesized by combining different primitives defining the behavior of the center of gravity, the motion of the hands, legs, and head, the body attitude and posture, and the constrained body parts such as joint limits and contacts. The motion‐generation framework including the specific motion modules and software architecture is discussed in detail. A rich perception system allows the robot to perceive and generate 3D representations of the environment as well as detect contacts and sense physical interaction force and moments. The operator station that pilots use to control the robot provides a rich pilot interface with different control modes and a number of teleoperated or semiautonomous command features. The capability of the robot and the performance of the individual motion control and perception modules were validated during the DRC in which the robot was able to demonstrate exceptional physical resilience and execute some of the tasks during the competition.
Moisture determination of the main insulation in a transformer by frequency‐domain spectroscopy
Authors: Yao Renyun , Zhou Quan , Yang Lijun , Gao Jun
Published: June 2017

The presence of moisture in the oil–paper insulation in a transformer drastically accelerates the aging process of the insulation and reduces the service life of the transformer. To analyse the influence of moisture on the dielectric response of the oil–paper insulation and to precisely determine the moisture content of the transformer by frequency‐domain spectroscopy, the modified Cole–Cole model is introduced to fit the frequency versus dielectric responses of the oil–paper insulation samples with different moisture contents, and the influence of the variation in moisture content on the parameters in the modified Cole–Cole model is investigated. Results show that the modified Cole–Cole model parameters, including the α and β relaxation components as well as the DC and hopping conductivity components, can be used to effectively fit the frequency versus dielectric response curve of the oil–paper insulation. The characteristic parameters τα and τβ in this model are found to be sensitive to changes in the moisture content. They can be used to quantitatively evaluate the moisture content in a transformer insulation system. A case study is presented to verify the effectiveness of the proposed technique in assessing the moisture content of onsite transformers. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Rare Earth Chalcogels NaLnSnS4 (Ln = Y, Gd, Tb) for Selective Adsorption of Volatile Hydrocarbons and Gases
Authors: Edhaim Fatimah , Rothenberger Alexander
Published: June 2017

The synthesis and characterization of the rare earth chalcogenide aerogels NaYSnS4, NaGdSnS4, and NaTbSnS4 is reported. Rare earth metal ions like Y3+, Gd3+, and Tb3+ react with the chalcogenide clusters [SnS4]4– in aqueous formamide solution forming extended polymeric networks by gelation. Aerogels obtained after supercritical drying have BET surface areas of 649 m2·g–1 (NaYSnS4), 479 m2·g–1 (NaGdSnS4), and 354 m2·g–1 (NaTbSnS4). Electron microscopy and physisorption studies reveal that the new materials have pores in the macro (above 50 nm) and meso (2–50 nm) regions. These aerogels show higher adsorption of toluene vapor over cyclohexane vapor and CO2 over CH4 or H2. The notable adsorption capacity for toluene (NaYSnS4: 1108 mg·g–1; NaGdSnS4: 921 mg·g–1; and NaTbSnS4: 645 mg·g–1) and high selectivity for gases (CO2/H2: 172 and CO2/CH4: 50 for NaYSnS4, CO2/H2: 155 and CO2/CH4: 37 for NaGdSnS4, and CO2/H2: 75 and CO2/CH4: 28 for NaTbSnS4) indicate potential future use of chalcogels in adsorption‐based gas or hydrocarbon separation processes.
A History of the Mind and Mental Health in Classical Greek Medical Thought
Authors: Thumiger Chiara
Published: June 2017

The Hippocratic texts and other contemporary medical sources have often been overlooked in discussions of ancient psychology. They have been considered to be more mechanical and less detailed than poetic and philosophical representations, as well as later medical texts such as those of Galen. This book does justice to these early medical accounts by demonstrating their richness and sophistication, their many connections with other contemporary cultural products and the indebtedness of later medicine to their observations. In addition, it reads these sources not only as archaeological documents but also in the light of methodological discussions that are fundamental to the histories of psychiatry and psychology. As a result of this approach, the book will be important for scholars of these disciplines as well as those of Greek literature and philosophy, strongly advocating the relevance of ancient ideas to modern debates.
Eighteen Hundred and Eleven
Authors: Clery E. J.
Published: June 2017

In 1811 England was on the brink of economic collapse and revolution. The veteran poet and campaigner Anna Letitia Barbauld published a prophecy of the British nation reduced to ruins by its refusal to end the interminable war with France, titled Eighteen Hundred and Eleven. Combining ground-breaking historical research with incisive textual analysis, this new study dispels the myth surrounding the hostile reception of the poem and takes a striking episode in Romantic-era culture as the basis for exploring poetry as a medium of political protest. Clery examines the issues at stake, from the nature of patriotism to the threat to public credit, and throws new light on the views and activities of a wide range of writers, including radical, loyalist and dissenting journalists, Coleridge, Wordsworth, Southey, and Barbauld herself. Putting a woman writer at the centre of the enquiry opens up a revised perspective on the politics of Romanticism.
Systematic review of the use of low-dose ketamine for analgesia in the emergency department
Authors: Ghate Gauri , Clark Eric , Vaillancourt Christian
Published: June 2017

Objectives

The aim of the study is to determine the performance of low-dose ketamine (LDK) as an analgesic for acute pain management in adult patients in the emergency department (ED).

Methods

We systematically reviewed electronic databases, grey literature, conference abstracts, and clinical trial registries. Two independent reviewers identified eligible studies. These selections were subsequently reviewed by one reviewer who identified the final eligible studies, using refined inclusion and exclusion criteria. Our outcome measures included the analgesic effect of LDK, need for rescue analgesia, and neuropsychological adverse events secondary to LDK use. We assessed inter-rater agreement using kappa statistics and proposed a treatment recommendation using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) software. Heterogeneity among studies precluded meta-analysis.

Results

Our electronic search identified 1,408 records; 44 were selected for full evaluation (kappa=0.70), and 8 were included after the final review. All six randomized controlled trials and two observational studies were set in the ED where LDK was administered to adult patients ( >18 years old) exclusively for pain management. All studies had an overall low risk of bias. There was extensive variation in the dose and route of LDK used (0.1-0.7 mg/kg SC/IV/IM), administration protocols, and use of adjunct analgesia. Overall, most studies reported a significant analgesic effect of LDK with occasional need for rescue analgesia and mild-to-moderate adverse events (dizziness, dysphoria, and confusion).

Conclusion

There are moderate to low quality data supporting LDK as an alternative analgesic in the ED with the potential for minimal requirement of rescue analgesia and self-limited neuropsychological adverse events.
Simplified Numerical Model for Rapid Design of AF Module Spring Shape Parameters
Authors: Liu D. S. , Lu C. J. , Chen S. H. , Liu C. S. , Liao T. W.
Published: June 2017

The autofocusing (AF) performance of cell phone cameras is critically dependent on the design of the voice-coil motor (VCM) used to drive the lens module. Also, the metal springs in the AF module should combine high stiffness with a good actuation response and a light weight. The present study utilizes a reverse engineering approach to construct three-dimensional finite element models of the top and bottom springs in the VCM mechanism. Simulations are then performed to investigate the von Mises stress distribution and stiffness characteristics of the two springs given horizontal and vertical orientations of the AF module, respectively. In performing the simulations, the actuation force is computed using two different analysis methods, namely a simplify structure method and a coupled electromagnetic-structural method. It is shown that the simplify structure method has the advantages of a lower computational complexity and a more comprehensive modeling capability. A further series of simulations is thus to examine the effects of the spring shape parameters on the reaction force developed by the spring stiffness. The results show that the spring stiffness increases with an increasing thickness and a decreasing rib length. The simulation results obtained for different spring shape parameter settings are summarized in the form of a parameter design chart for predicting the reaction force given known values of the spring rib length and spring thickness.
Low levels of very-long-chainn-3 PUFA in Atlantic salmon (Salmo salar) diet reduce fish robustness under challenging conditions in sea cages
Authors: Bou Marta , Berge Gerd M. , Baeverfjord Grete , Sigholt Trygve , Østbye Tone-Kari , Ruyter Bente
Published: June 2017

The present study aimed to determine the minimum requirements of the essentialn-3 fatty acids EPA and DHA in Atlantic salmon (Salmo salar) that can secure their health under challenging conditions in sea cages. Individually tagged Atlantic salmon were fed 2, 10 and 17 g/kg of EPA + DHA from 400 g until slaughter size (about 3·5 kg). The experimental fish reared in sea cages were subjected to the challenging conditions typically experienced under commercial production. Salmon receiving the lowest EPA + DHA levels showed lower growth rates in the earlier life stages, but no significant difference in final weights at slaughter. The fatty acid composition of various tissues and organs had remarkably changed. The decreased EPA + DHA in the different tissue membrane phospholipids were typically replaced by pro-inflammatoryn-6 fatty acids, most markedly in the skin. The EPA + DHA levels were maintained at a higher level in the liver and erythrocytes than in the muscle, intestine and skin. After delousing at high water temperatures, the mortality rates were 63, 52 and 16 % in the salmon fed 2, 10 and 17 g/kg EPA + DHA. Low EPA + DHA levels also increased the liver, intestinal and visceral fat amount, reduced intervertebral space and caused mid-intestinal hyper-vacuolisation. Thus, 10 g/kg EPA + DHA in the Atlantic salmon diet, a level previously regarded as sufficient, was found to be too low to maintain fish health under demanding environmental conditions in sea cages.
Quaternary marine ingressions as indicated by hydrogeochemical evidence in the semi-confined aquifer of the littoral of the Río de la Plata, Argentina
Authors: Santucci Lucia , Carol Eleonora , Kruse Eduardo
Published: June 2017

The Quaternary is characterized by the occurrence of significant climate oscillations that led to noticeable sea-level changes. On the basis of hydrochemical indicators, the origin of the water salinity in the semi-confined aquifer in the region of the middle Río de la Plata estuary, Argentina is determined. Exploration wells were drilled and sediments were sampled for mineralogical analysis alongside water samples collected to determine major and minor ions and environmental isotopes in the aquifer. The Plio-Pleistocene fluvial sands in which the aquifer occurs are mainly composed of grains of quartz, feldspar, and mafic minerals. The water chemistry shows Na-Cl facies with a marked increase in salinity towards the Río de la Plata. The δ 18O vs. δ 2H, Br− vs. Cl−, and δ 18O vs. Cl− ratios clearly trend towards seawater. Minor ions, such as Si, Sr, Li, Se, Br, and Rb, were the result of the prolonged interaction between the water that occurs in the aquifer and the mineral components of its matrix. The hydrogeochemical data show the marine origin of the saline water and that the hydrogeological evolution of the area during the Quaternary is as a result of sea-level oscillations.
Gendering Public Policy or Rationalizing Gender? Strategic Interventions and GBA+ Practice in Canada
Authors: Scala Francesca , Paterson Stephanie
Published: June 2017

The debate surrounding the transformative potential of gender mainstreaming has revived concerns of co-optation of equality work and resistance first expressed by early feminist public administration scholars. In this article, we explore how gender analysts exercised their agency and carved out spaces within the bureaucracy to articulate and advance a gender focus in policy work. Employing discursive, institutional and relational strategies, gender analysts simultaneously used and pushed back against hierarchical bureaucratic discourses as they operationalized Gender-Based Analysis Plus (GBA+) in the federal public bureaucracy. These micro-level acts of resistance, on their own, do not lead to social transformation. However, by creating spaces for feminist knowledge and activism within the state, these local strategies can contribute to the broader feminist agenda.
Redefining Alliances in the Struggle for Organizational Autonomy
Authors: Morales Hudon Anahi
Published: June 2017

This paper aims to contribute to discussions around alliances and collaborations between feminisms. It analyses relations between movements in the development of indigenous women's organizational autonomy in Mexico. It seeks to understand how the struggle for autonomy involved a redefinition of the forms of collaboration by indigenous women in the consolidation of their movement. An intersectional perspective is proposed to better understand how power relations affect the organizing processes of social movements, as well as how organizations and individuals respond to and challenge them. I argue here that the redefinition of collaborations and alliances has been a key determinant in the organizing capacity of indigenous women to position themselves as autonomous political actors. From the analysis of two specific cases, this paper poses broader questions regarding representation and autonomy that may be applied towards a reflection of our feminist practices and discourses of solidarity.
Finding Feminism(s) in Canadian Political Science Scholarship: Diversity and Resistance in an Era of Global Uncertainty
Authors: Dobrowolsky Alexandra , MacDonald Fiona , Raney Tracey , Collier Cheryl N. , Dufour Pascale
Published: June 2017

It is with great pleasure that we present this special issue showcasing contemporary feminist political research, theories and practices in Canada. In an era characterized by global movements and numerous transformations that range from the economic to the environmental, the political to the cultural, from macro- through to micro-scales, including complex debates about the fluidity of gender, and where “backlash” against the symbols and agents of past feminist activism is rife, this special issue queries where do we find feminism(s) today? The responses to this question, as well as to the interrogation of the place of gender in the discipline of political science more generally, are undoubtedly diverse and contested. The collective efforts contained in this special issue feature a mere taste of the rich range of thought-provoking recent scholarship on feminisms. And even with this necessarily condensed portrayal (the articles in this issue are shorter than is normally the case to allow for more work to be featured), the special issue is ground-breaking in that it marks the first time the Canadian Journal of Political Science/Revue canadienne de science politique has dedicated an entire issue to topics of gender and feminisms.
Spectral analysis of forced turbulence in a non-neutral plasma
Authors: Chen S. , Maero G. , Romé M.
Published: June 2017

The paper investigates the dynamics of magnetized non-neutral (electron) plasmas subjected to external electric field perturbations. A two-dimensional (2-D) particle-in-cell code is effectively exploited to model this system with a special attention to the role that non-axisymmetric, multipolar radio frequency (RF) drives applied to the cylindrical (circular) boundary play on the insurgence of azimuthal instabilities and the subsequent formation of coherent structures preventing the relaxation to a fully developed turbulent state, when the RF fields are chosen in the frequency range of the low-order fluid modes themselves. The isomorphism of such system with a 2-D inviscid incompressible fluid offers an insight into the details of forced 2-D fluid turbulence. The choice of different initial density (i.e. fluid vorticity) distributions allows for a selection of conditions where different levels of turbulence and intermittency are expected and a range of final states is achieved. Integral and spectral quantities of interest are computed along the flow using a multiresolution analysis based on a wavelet decomposition of both enstrophy and energy 2-D maps. The analysis of a variety of cases shows that the qualitative features of turbulent relaxation are similar in conditions of both free and forced evolution; at the same time, fine details of the flow beyond the self-similarity turbulence properties are highlighted in particular in the formation of structures and their timing, where the influence of the initial conditions and the effect of the external forcing can be distinguished.
Positive solutions of Kirchhoff-type non-local elliptic equation: a bifurcation approach
Authors: Liang Zhanping , Li Fuyi , Shi Junping
Published: June 2017

Positive solutions of a Kirchhoff-type nonlinear elliptic equation with a non-local integral term on a bounded domain in ℝN, N ⩾ 1, are studied by using bifurcation theory. The parameter regions of existence, non-existence and uniqueness of positive solutions are characterized by the eigenvalues of a linear eigenvalue problem and a nonlinear eigenvalue problem. Local and global bifurcation diagrams of positive solutions for various parameter regions are obtained.
On relation between constraint answer set programming and satisfiability modulo theories
Authors: LIERLER YULIYA , SUSMAN BENJAMIN
Published: June 2017

Constraint answer set programming is a promising research direction that integrates answer set programming with constraint processing. It is often informally related to the field of satisfiability modulo theories. Yet, the exact formal link is obscured as the terminology and concepts used in these two research areas differ. In this paper, we connect these two research areas by uncovering the precise formal relation between them. We believe that this work will boost the cross-fertilization of the theoretical foundations and the existing solving methods in both areas. As a step in this direction, we provide a translation from constraint answer set programs with integer linear constraints to satisfiability modulo linear integer arithmetic that paves the way to utilizing modern satisfiability modulo theories solvers for computing answer sets of constraint answer set programs.
How Shifting Winds Turn Tropical Storms into Hurricanes
Authors: Underwood Emily
Published: June 2017

Researchers present a novel method for analyzing how wind shear affects tropical cyclone strength and structure.
Exsolution trends and co-segregation aspects of self-grown catalyst nanoparticles in perovskites
Authors: Kwon Ohhun , Sengodan Sivaprakash , Kim Kyeounghak , Kim Gihyeon , Jeong Hu Young , Shin Jeeyoung , Ju Young-Wan , Han Jeong Woo , Kim Guntae
Published: June 2017

In perovskites, exsolution of transition metals has been proposed as a smart catalyst design for energy applications. Although there exist transition metals with superior catalytic activity, they are limited by their ability to exsolve under a reducing environment. When a doping element is present in the perovskite, it is often observed that the surface segregation of the doping element is changed by oxygen vacancies. However, the mechanism of co-segregation of doping element with oxygen vacancies is still an open question. Here we report trends in the exsolution of transition metal (Mn, Co, Ni and Fe) on the PrBaMn2O5+δ layered perovskite oxide related to the co-segregation energy. Transmission electron microscopic observations show that easily reducible cations (Mn, Co and Ni) are exsolved from the perovskite depending on the transition metal-perovskite reducibility. In addition, using density functional calculations we reveal that co-segregation of B-site dopant and oxygen vacancies plays a central role in the exsolution.
Light controlled 3D micromotors powered by bacteria
Authors: Vizsnyiczai Gaszton , Frangipane Giacomo , Maggi Claudio , Saglimbeni Filippo , Bianchi Silvio , Di Leonardo Roberto
Published: June 2017

Self-propelled bacteria can be integrated into synthetic micromachines and act as biological propellers. So far, proposed designs suffer from low reproducibility, large noise levels or lack of tunability. Here we demonstrate that fast, reliable and tunable bio-hybrid micromotors can be obtained by the self-assembly of synthetic structures with genetically engineered biological propellers. The synthetic components consist of 3D interconnected structures having a rotating unit that can capture individual bacteria into an array of microchambers so that cells contribute maximally to the applied torque. Bacterial cells are smooth swimmers expressing a light-driven proton pump that allows to optically control their swimming speed. Using a spatial light modulator, we can address individual motors with tunable light intensities allowing the dynamic control of their rotational speeds. Applying a real-time feedback control loop, we can also command a set of micromotors to rotate in unison with a prescribed angular speed.
MARK4 regulates NLRP3 positioning and inflammasome activation through a microtubule-dependent mechanism
Authors: Li Xuan , Thome Sarah , Ma Xiaodan , Amrute-Nayak Mamta , Finigan Alison , Kitt Lauren , Masters Leanne , James John R. , Shi Yuguang , Meng Guoyu , Mallat Ziad
Published: June 2017

Excessive activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome is involved in many chronic inflammatory diseases, including cardiovascular and Alzheimer’s disease. Here we show that microtubule-affinity regulating kinase 4 (MARK4) binds to NLRP3 and drives it to the microtubule-organizing centre, enabling the formation of one large inflammasome speck complex within a single cell. MARK4 knockdown or knockout, or disruption of MARK4-NLRP3 interaction, impairs NLRP3 spatial arrangement and limits inflammasome activation. Our results demonstrate how an evolutionarily conserved protein involved in the regulation of microtubule dynamics orchestrates NLRP3 inflammasome activation by controlling its transport to optimal activation sites, and identify a targetable function for MARK4 in the control of innate immunity.
Skin parasite landscape determines host infectiousness in visceral leishmaniasis
Authors: Doehl Johannes S. P. , Bright Zoe , Dey Shoumit , Davies Helen , Magson John , Brown Najmeeyah , Romano Audrey , Dalton Jane E. , Pinto Ana I. , Pitchford Jon W. , Kaye Paul M.
Published: June 2017

Increasing evidence suggests that the infectiousness of patients for the sand fly vector of visceral leishmaniasis is linked to parasites found in the skin. Using a murine model that supports extensive skin infection with Leishmania donovani, spatial analyses at macro-(quantitative PCR) and micro-(confocal microscopy) scales indicate that parasite distribution is markedly skewed. Mathematical models accounting for this heterogeneity demonstrate that while a patchy distribution reduces the expected number of sand flies acquiring parasites, it increases the infection load for sand flies feeding on a patch, increasing their potential for onward transmission. Models representing patchiness at both macro- and micro-scales provide the best fit with experimental sand fly feeding data, pointing to the importance of the skin parasite landscape as a predictor of host infectiousness. Our analysis highlights the skin as a critical site to consider when assessing treatment efficacy, transmission competence and the impact of visceral leishmaniasis elimination campaigns.
A blueprint for the next generation of ELSI research, training, and outreach in regenerative medicine
Authors: Illes Judy , Sipp Douglas , Kleiderman Erika , Benjaminy Shelly , Isasi Rosario , Lomax Geoff , Master Zubin , McCormick Jennifer , Ogbogu Ubaka , Ravitsky Vardit , Robillard Julie M. , Rossi Fabio , Wilson Brenda , Zarzeczny Amy
Published: June 2017

Regenerative medicine has attracted the interest of scientists, physicians, and patient communities, and as well as policy-makers and the broader public given related ethical, legal, and social implications. Here we examine past initiatives in the ethical, legal and social implications arena in regenerative medicine, and offer our views on actionable priorities for the future in six key areas: capacity building, policy, engagement with industry, resaerch ethics, communication, and community building.
A novel synthetic approach of cerium oxide nanoparticles with improved biomedical activity
Authors: Caputo Fanny , Mameli Marta , Sienkiewicz Andrzej , Licoccia Silvia , Stellacci Francesco , Ghibelli Lina , Traversa Enrico
Published: June 2017

Cerium oxide nanoparticles (CNPs) are novel synthetic antioxidant agents proposed for treating oxidative stress-related diseases. The synthesis of high-quality CNPs for biomedical applications remains a challenging task. A major concern for a safe use of CNPs as pharmacological agents is their tendency to agglomerate. Herein we present a simple direct precipitation approach, exploiting ethylene glycol as synthesis co-factor, to synthesize at room temperature nanocrystalline sub-10 nm CNPs, followed by a surface silanization approach to improve nanoparticle dispersibility in biological fluids. CNPs were characterized using transmission electron microscopy (TEM) observations, X-ray diffraction (XRD) analysis, thermogravimetric analysis (TGA), Fourier-transform infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance (1H-NMR) spectroscopy, dynamic light scattering (DLS) and zeta potential measurements. CNP redox activity was studied in abiotic systems using electron spin resonance (ESR) measurements, and in vitro on human cell models. In-situ silanization improved CNP colloidal stability, in comparison with non-functionalized particles, and allowed at the same time improving their original biological activity, yielding thus functionalized CNPs suitable for biomedical applications.
RETRACTED ARTICLE: The lincRNA-ROR/miR-145 axis promotes invasion and metastasis in hepatocellular carcinoma via induction of epithelial-mesenchymal transition by targeting ZEB2
Authors: Li Chen , Lu Lu , Feng Bing , Zhang Kai , Han Siqi , Hou Daorong , Chen Longbang , Chu Xiaoyuan , Wang Rui
Published: June 2017

Emerging evidence show that long noncoding RNAs (lncRNAs) play critical roles in tumor development. LincRNA-ROR (linc-ROR) is known to promote tumor progress in several human cancers, including hepatocellular carcinoma (HCC). Nevertheless, the roles of linc-ROR in HCC metastasis and its underlying mechanisms remain fully unclear. In the present study, we showed that linc-ROR was upregulated in HCC tissues and high linc-ROR expression level predicted poor prognosis. Functionally, linc-ROR significantly induced epithelial-mesenchymal transition (EMT), and increased in vitro invasion and in vivo metastasis of HCC cells. Mechanistically, linc-ROR acted as a sponge for miR-145 to de-repress the expression of target gene ZEB2, thereby inducing EMT and promoting HCC metastasis. Collectively, our research indicates the potential of linc-ROR as a vital therapeutic target for the treatment of aggressive and metastatic HCC.
iTRAQ-Based Quantitative Proteomic Analysis of the Inhibitory Effects of Polysaccharides from Viscum coloratum (Kom.) Nakai on HepG2 Cells
Authors: Chai Yangyang , Zhao Min
Published: June 2017

Viscum coloratum (Kom.) Nakai is one of active medicinal plants, and its active components, especially polysaccharides, have been shown to exhibit bioactivity. In this study, we examined the effects of three polysaccharide fractions from Viscum coloratum (Kom.) Nakai on HepG2 cell growth in a dose-dependent manner by using a CCK-8 assay kit. Flow cytometry analysis showed that VCP2 treatment delayed the cell cycle in the G1 phase and induced apoptosis in HepG2 cells, a result possibly due to the increased expression of p21Wafl/Cip1 and Cyclin D and the decreased expression of Cyclin E and CDK4. The increased expression of Bad, Smac and Caspase-3 and the decreased expression of Bcl-XL and XIAP may be some of the reasons for the induction of apoptosis in VCP2-treated HepG2 cells. Through iTRAQ and 2D-LC-MSMS, 113 and 198 differentially expressed proteins were identified in normal and VCP2-treated HepG2 and Caco2 cells. The mRNA and protein levels of Histone H3.1, Cytoskeletal 9 and Vitronectin agreed with iTRAQ proteomic results. GO, pathways and the PPI of differentially expressed proteins were further analyzed. These findings broaden the understanding of the anti-tumor mechanisms of mistletoe polysaccharides and provide new clues for screening proteins that are responsive to polysaccharides.
Increased Stability and Breakdown of Brain Effective Connectivity During Slow-Wave Sleep: Mechanistic Insights from Whole-Brain Computational Modelling
Authors: Jobst Beatrice M. , Hindriks Rikkert , Laufs Helmut , Tagliazucchi Enzo , Hahn Gerald , Ponce-Alvarez Adrián , Stevner Angus B. A. , Kringelbach Morten L. , Deco Gustavo
Published: June 2017

Recent research has found that the human sleep cycle is characterised by changes in spatiotemporal patterns of brain activity. Yet, we are still missing a mechanistic explanation of the local neuronal dynamics underlying these changes. We used whole-brain computational modelling to study the differences in global brain functional connectivity and synchrony of fMRI activity in healthy humans during wakefulness and slow-wave sleep. We applied a whole-brain model based on the normal form of a supercritical Hopf bifurcation and studied the dynamical changes when adapting the bifurcation parameter for all brain nodes to best match wakefulness and slow-wave sleep. Furthermore, we analysed differences in effective connectivity between the two states. In addition to significant changes in functional connectivity, synchrony and metastability, this analysis revealed a significant shift of the global dynamic working point of brain dynamics, from the edge of the transition between damped to sustained oscillations during wakefulness, to a stable focus during slow-wave sleep. Moreover, we identified a significant global decrease in effective interactions during slow-wave sleep. These results suggest a mechanism for the empirical functional changes observed during slow-wave sleep, namely a global shift of the brain’s dynamic working point leading to increased stability and decreased effective connectivity.
Sorghum Dw2 Encodes a Protein Kinase Regulator of Stem Internode Length
Authors: Hilley Josie L. , Weers Brock D. , Truong Sandra K. , McCormick Ryan F. , Mattison Ashley J. , McKinley Brian A. , Morishige Daryl T. , Mullet John E.
Published: June 2017

Sorghum is an important C4 grass crop grown for grain, forage, sugar, and bioenergy production. While tall, late flowering landraces are commonly grown in Africa, short early flowering varieties were selected in US grain sorghum breeding programs to reduce lodging and to facilitate machine harvesting. Four loci have been identified that affect stem length (Dw1-Dw4). Subsequent research showed thatDw3encodes an ABCB1 auxin transporter andDw1encodes a highly conserved protein involved in the regulation of cell proliferation. In this study,Dw2was identified by fine-mapping and further confirmed by sequencing theDw2alleles in Dwarf Yellow Milo and Double Dwarf Yellow Milo, the progenitor genotypes where the recessive allele ofdw2originated. TheDw2locus was determined to correspond to Sobic.006G067700, a gene that encodes a protein kinase that is homologous to KIPK, a member of the AGCVIII subgroup of the AGC protein kinase family in Arabidopsis.
Selective mass enhancement close to the quantum critical point in BaFe2(As1−x
P
x
)2
Authors: Grinenko V. , Iida K. , Kurth F. , Efremov D. V. , Drechsler S.-L. , Cherniavskii I. , Morozov I. , Hänisch J. , Förster T. , Tarantini C. , Jaroszynski J. , Maiorov B. , Jaime M. , Yamamoto A. , Nakamura I. , Fujimoto R. , Hatano T. , Ikuta H. , Hühne R.
Published: June 2017

A quantum critical point (QCP) is currently being conjectured for the BaFe2(As1−x
P
x
)2 system at the critical value x
c
 ≈ 0.3. In the proximity of a QCP, all thermodynamic and transport properties are expected to scale with a single characteristic energy, given by the quantum fluctuations. Such a universal behavior has not, however, been found in the superconducting upper critical field Hc2. Here we report Hc2 data for epitaxial thin films extracted from the electrical resistance measured in very high magnetic fields up to 67 Tesla. Using a multi-band analysis we find that Hc2 is sensitive to the QCP, implying a significant charge carrier effective mass enhancement at the doping-induced QCP that is essentially band-dependent. Our results point to two qualitatively different groups of electrons in BaFe2(As1−x
P
x
)2. The first one (possibly associated to hot spots or whole Fermi sheets) has a strong mass enhancement at the QCP, and the second one is insensitive to the QCP. The observed duality could also be present in many other quantum critical systems.
Extracellular matrix promotes clathrin-dependent endocytosis of prolactin and STAT5 activation in differentiating mammary epithelial cells
Authors: Bridgewater Rebecca E. , Streuli Charles H. , Caswell Patrick T.
Published: June 2017

The hormone prolactin promotes lactational differentiation of mammary epithelial cells (MECs) via its cognate receptor and the downstream JAK2-STAT5a signalling pathway. In turn this regulates transcription of milk protein genes. Prolactin signalling depends on a cross-talk with basement membrane extracellular matrix (ECM) via β1 integrins which activate both ILK and Rac1 and are required for STAT5a activation and lactational differentiation. Endocytosis is an important regulator of signalling. It can both enhance and suppress cytokine signalling, although the role of endocytosis for prolactin signalling is not known. Here we show that clathrin-mediated endocytosis is required for ECM-dependent STAT5 activation. In the presence of ECM, prolactin is internalised via a clathrin-dependent, but caveolin-independent, route. This occurs independently from JAK2 and Rac signalling, but is required for full phosphorylation and activation of STAT5. Prolactin is internalised into early endosomes, where the master early endosome regulator Rab5b promotes STAT5 phosphorylation. These data reveal a novel role for ECM-driven endocytosis in the positive regulation of cytokine signalling.
Coherent scatter-controlled phase-change grating structures in silicon using femtosecond laser pulses
Authors: Fuentes-Edfuf Yasser , Garcia-Lechuga Mario , Puerto Daniel , Florian Camilo , Garcia-Leis Adianez , Sanchez-Cortes Santiago , Solis Javier , Siegel Jan
Published: June 2017

Periodic structures of alternating amorphous-crystalline fringes have been fabricated in silicon using repetitive femtosecond laser exposure (800 nm wavelength and 120 fs duration). The method is based on the interference of the incident laser light with far- and near-field scattered light, leading to local melting at the interference maxima, as demonstrated by femtosecond microscopy. Exploiting this strategy, lines of highly regular amorphous fringes can be written. The fringes have been characterized in detail using optical microscopy combined modelling, which enables a determination of the three-dimensional shape of individual fringes. 2D micro-Raman spectroscopy reveals that the space between amorphous fringes remains crystalline. We demonstrate that the fringe period can be tuned over a range of 410 nm – 13 µm by changing the angle of incidence and inverting the beam scan direction. Fine control over the lateral dimensions, thickness, surface depression and optical contrast of the fringes is obtained via adjustment of pulse number, fluence and spot size. Large-area, highly homogeneous gratings composed of amorphous fringes with micrometer width and millimeter length can readily be fabricated. The here presented fabrication technique is expected to have applications in the fields of optics, nanoelectronics, and mechatronics and should be applicable to other materials.
HLA-E Presents Glycopeptides from the Mycobacterium tuberculosis Protein MPT32 to Human CD8+ T cells
Authors: Harriff Melanie J. , Wolfe Lisa M. , Swarbrick Gwendolyn , Null Megan , Cansler Meghan E. , Canfield Elizabeth T. , Vogt Todd , Toren Katelynne Gardner , Li Wei , Jackson Mary , Lewinsohn Deborah A. , Dobos Karen M. , Lewinsohn David M.
Published: June 2017

Infection withMycobacterium tuberculosis(Mtb), the bacterium that causes tuberculosis, remains a global health concern. Both classically and non-classically restricted cytotoxic CD8+T cells are important to the control of Mtb infection. We and others have demonstrated that the non-classical MHC I molecule HLA-E can present pathogen-derived peptides to CD8+T cells. In this manuscript, we identified the antigen recognized by an HLA-E-restricted CD8+T cell clone isolated from an Mtb latently infected individual as a peptide from the Mtb protein, MPT32. Recognition by the CD8+T cell clone required N-terminal O-linked mannosylation of MPT32 by a mannosyltransferase encoded by the Rv1002c gene. This is the first description of a post-translationally modified Mtb-derived protein antigen presented in the context of an HLA-E specific CD8+T cell immune response. The identification of an immune response that targets a unique mycobacterial modification is novel and may have practical impact in the development of vaccines and diagnostics.