bluuebunny/crossref_metadata_2025_split huggingface dataset:
Defect Formation Mechanisms
in Selective Laser Melting: A Review
Authors: Zhang Bi , Li Yongtao , Bai Qian 
Published: February 2018

AbstractDefect formation is a common problem in selective laser
melting (SLM). This paper provides a review of defect formation
mechanisms in SLM. It summarizes the recent research outcomes on
defect findings and classification, analyzes formation mechanisms of
the common defects, such as porosities, incomplete fusion holes, and
cracks. The paper discusses the effect of the process parameters on
defect formation and the impact of defect formation on the
mechanical properties of a fabricated part. Based on the discussion,
the paper proposes strategies for defect suppression and control in
SLM.
Pulsed Eddy Current Non-destructive
Testing and Evaluation: A Review
Authors: Sophian Ali , Tian Guiyun , Fan Mengbao 
Published: February 2018

AbstractPulsed eddy current (PEC) non-destructive testing and evaluation
(NDT&E) has been around for some time and it is still attracting extensive
attention from researchers around the globe, which can be witnessed through the
reports reviewed in this paper. Thanks to its richness of spectral components,
various applications of this technique have been proposed and reported in the
literature covering both structural integrity inspection and material
characterization in various industrial sectors. To support its development and for
better understanding of the phenomena around the transient induced eddy currents,
attempts for its modelling both analytically and numerically have been made by
researchers around the world. This review is an attempt to capture the
state-of-the-art development and applications of PEC, especially in the last
15 years and it is not intended to be exhaustive. Future challenges and
opportunities for PEC NDT&E are also presented.
Proteasome inhibition and mechanism of resistance to a synthetic, library-based hexapeptide
Authors: Oerlemans Ruud , Berkers Celia R. , Assaraf Yehuda G. , Scheffer George L. , Peters Godefridus J. , Verbrugge Sue Ellen , Cloos Jacqueline , Slootstra Jerry , Meloen Rob H. , Shoemaker Robert H. , Dijkmans Ben A. C. , Scheper Rik J. , Ovaa Huib , Jansen Gerrit 
Published: February 2018

Summary
Background The hexapeptide 4A6 (Ac-Thr(tBu)-His(Bzl)-Thr(Bzl)-Nle-Glu(OtBu)-Gly-Bza) was isolated from a peptide library constructed to identify peptide-based transport inhibitors of multidrug resistance (MDR) efflux pumps including P-glycoprotein and Multidrug Resistance-associated Protein 1. 4A6 proved to be a substrate but not an inhibitor of these MDR efflux transporters. In fact, 4A6 and related peptides displayed potent cytotoxic activity via an unknown mechanism. Objective To decipher the mode of cytotoxic activity of 4A6. Methods Screening of 4A6 activity was performed against the NCI60 panel of cancer cell lines. Possible interactions of 4A6 with the 26S proteasome were assessed via proteasome activity and affinity labeling, and cell growth inhibition studies with leukemic cells resistant to the proteasome inhibitor bortezomib (BTZ). Results The NCI60 panel COMPARE analysis revealed that 4A6 had an activity profile overlapping with BTZ. Consistently, 4A6 proved to be a selective and reversible inhibitor of β5 subunit (PSMB5)-associated chymotrypsin-like activity of the 26S proteasome. This conclusion is supported by several lines of evidence: (i) inhibition of chymotrypsin-like proteasome activity by 4A6 and related peptides correlated with their cell growth inhibition potencies; (ii) 4A6 reversibly inhibited functional β5 active site labeling with the affinity probe BodipyFL-Ahx3L3VS; and (iii) human myeloid THP1 cells with acquired BTZ resistance due to mutated PSMB5 were highly (up to 287-fold) cross-resistant to 4A6 and its related peptides. Conclusion 4A6 is a novel specific inhibitor of the β5 subunit-associated chymotrypsin-like proteasome activity. Further exploration of 4A6 as a lead compound for development as a novel
proteasome-targeted drug is warranted.
Diversity and functional traits of lichens in ultramafic areas: a literature‐based worldwide analysis integrated by field data at the regional scale
Authors: Favero‐Longo Sergio E. , Matteucci Enrica , Giordani Paolo , Paukov Alexander G. , Rajakaruna Nishanta 
Published: February 2018

AbstractWhile higher plant communities found on ultramafics are known to display peculiar characteristics, the distinguishability of any peculiarity in lichen communities is still a matter of contention. Other biotic or abiotic factors, rather than substrate chemistry, may contribute to differences in species composition reported for lichens on adjacent ultramafic and non‐ultramafic areas. This work examines the lichen biota of ultramafics, at global and regional scales, with reference to species‐specific functional traits. An updated world list of lichens on ultramafic substrates was analyzed to verify potential relationships between diversity and functional traits of lichens in different Köppen–Geiger climate zones. Moreover, a survey of diversity and functional traits in saxicolous communities on ultramafic and non‐ultramafic substrates was conducted in Valle d'Aosta (North‐West Italy) to verify whether a relationship can be detected between substrate and functional traits that cannot be explained by other environmental factors related to altitude. Analyses (unweighted pair group mean average clustering, canonical correspondence analysis, similarity‐difference‐replacement simplex approach) of global lichen diversity on ultramafic substrates (2314 reports of 881 taxa from 43 areas) displayed a zonal species distribution in different climate zones rather than an azonal distribution driven by the shared substrate. Accordingly, variations in the frequency of functional attributes reflected reported adaptations to the climate conditions of the different geographic areas. At the regional scale, higher similarity and lower species replacement were detected at each altitude, independent from the substrate, suggesting that altitude‐related climate factors prevail over putative substrate–factors in driving community assemblages. In conclusion, data do not reveal peculiarities in lichen diversity or the frequency of functional traits in ultramafic areas.
On the Coupling Mechanism of Equiaxed Crystal Generation with the Liquid Flow Driven by Natural Convection During Solidification
Authors: Stefan-Kharicha Mihaela , Kharicha Abdellah , Wu Menghuai , Ludwig Andreas 
Published: February 2018

Abstract
The influence of the melt flow on the solidification structure is bilateral. The flow plays an important role in the solidification pattern, via the heat transfer, grain distribution, and segregations. On the other hand, the crystal structure, columnar or equiaxed, impacts the flow, via the thermosolutal convection, the drag force applied by the crystals on the melt flow, etc. As the aim of this research was to further explore the solidification–flow interaction, experiments were conducted in a cast cell (95 * 95 * 30 mm3), in which an ammonium chloride–water solution (between 27 and 31 wt pct NH4Cl) was observed as it solidified. The kinetic energy (KE) of the flow and the average flow velocity were calculated throughout the process. Measurements of the volume extension of the mush in the cell and the velocity of the solid front were also taken during the solidification experiment. During the mainly columnar experiments (8 cm liquid height) the flow KE continuously decreased over time. However, during the later series of experiments at higher liquid height (9.5 cm), the flow KE evolution presented a strong peak shortly after the start of solidification. This increase in the total flow KE correlated with the presence of falling equiaxed crystals. Generally, a clear correlation between the strength of the flow and the occurrence of equiaxed crystals was evident. The analysis of the results strongly suggests a fragmentation origin of equiaxed crystals appearing in the melt. The transition from purely columnar growth to a strongly equiaxed rain (CET) was found to be triggered by (a) the magnitude of the coupling between the flow intensity driven by the equiaxed crystals, and (b) the release and transport of the fragments by the same flow recirculating within the mushy zone.

Graphical Abstract
Coupling mechanism at the origin of CET: 1-2 strong flow running through the mush transporting out dendrite fragments (white dots); 3-4 equiaxed growth and drag of the downward flow. If the vortex is sufficiently stable, the horizontal configuration can lead to freckle appearing; a) vertical solidification front; b) horizontal solidification front.
Lumbar Intraspinal Spindle Cell Rhabdomyosarcoma as a Rare Cause of Spinal Stenosis: A Case Report
Authors: Sequea Donel A. , Reese Maria E. 
Published: February 2018

AbstractRhabdomyosarcoma (RMS) represents the most common sarcoma in childhood yet is extremely rare in adults, with only a handful of cases reported. Here we present a case of intraspinal spindle cell RMS in an adult who presented as a typical case of spinal stenosis. To our knowledge, this is the first reported case of lumbar intraspinal spindle cell RMS in an adult patient. Furthermore, RMS phenotypically presents more aggressively in adults compared with children.Level of EvidenceV
Ideas, politics and practices of integrated science teaching in the global Cold War
Authors: NIELSEN KRISTIAN H. 
Published: February 2018

AbstractDuring the Cold War, UNESCO played a major role in promoting science education across the world. UNESCO's Programme in Integrated Science Teaching, launched in 1969, placed science education at the heart of socio-economic development in all nations. The programme planners emphasized the role of science education in the development of human resources necessary to build a modern nation state, seeking to build a scientific and engineering mindset in children. UNESCO's interest in science education drew inspiration from early Cold War curriculum reforms in the United States, where scientists, psychologists and teachers promoted science education as a way to enhance the scientific and technical workforce and to counteract irrational tendencies. While US curriculum reformers were concerned about the quantity and quality of science teaching in secondary school, UNESCO wanted to introduce science as a topic in primary, secondary and vocational schools, promoting integrated science teaching as the best way to do this. From the outset, the term ‘integrated’ meant different things to different people. It not only entailed less focus on scientific disciplines and scientific method strictly defined, but also more on teaching children how to adopt a curious, experimental and engineering approach in life. By the end of the Cold War, UNESCO abandoned the idea of integrated science teaching, but it has a lasting legacy in terms of placing ways of teaching science to children at the heart of modern society.
Parametric instability and wave turbulence driven by tidal excitation of internal waves
Authors: Le Reun Thomas , Favier Benjamin , Le Bars Michael 
Published: February 2018

We investigate the stability of stratified fluid layers undergoing homogeneous and periodic tidal deformation. We first introduce a local model which allows us to study velocity and buoyancy fluctuations in a Lagrangian domain periodically stretched and sheared by the tidal base flow. While keeping the key physical ingredients only, such a model is efficient in simulating planetary regimes where tidal amplitudes and dissipation are small. With this model, we prove that tidal flows are able to drive parametric subharmonic resonances of internal waves, in a way reminiscent of the elliptical instability in rotating fluids. The growth rates computed via direct numerical simulations (DNSs) are in very good agreement with Wentzel–Kramers–Brillouin analysis and Floquet theory. We also investigate the turbulence driven by this instability mechanism. With spatio-temporal analysis, we show that it is weak internal wave turbulence occurring at small Froude and buoyancy Reynolds numbers. When the gap between the excitation and the Brunt–Väisälä frequencies is increased, the frequency spectrum of this wave turbulence displays a $-2$ power law reminiscent of the high-frequency branch of the Garett and Munk spectrum (Geophys. Fluid Dyn., vol. 3 (1), 1972, pp. 225–264) which has been measured in the oceans. In addition, we find that the mixing efficiency is altered compared to what is computed in the context of DNS of stratified turbulence excited at small Froude and large buoyancy Reynolds numbers and is consistent with a superposition of waves.
Turbulence and secondary motions in square duct flow
Authors: Pirozzoli Sergio , Modesti Davide , Orlandi Paolo , Grasso Francesco 
Published: February 2018

We study turbulent flows in pressure-driven ducts with square cross-section through direct numerical simulation in a wide enough range of Reynolds number to reach flow conditions which are representative of fully developed turbulence ($Re_{\unicode[STIX]{x1D70F}}\approx 1000$). Numerical simulations are carried out over very long integration times to get adequate convergence of the flow statistics, and specifically to achieve high-fidelity representation of the secondary motions which arise. The intensity of the latter is found to be on the order of 1 %–2 % of the bulk velocity, and approximately unaffected by Reynolds number variation, at least in the range under scrutiny. The smallness of the mean convection terms in the streamwise vorticity equation points to a simple characterization of the secondary flows, which in the asymptotic high-$Re$regime are approximated with good accuracy by eigenfunctions of the Laplace operator, in the core part of the duct. Despite their effect of redistributing the wall shear stress along the duct perimeter, we find that secondary motions do not have a large influence on the bulk flow properties, and the streamwise velocity field can be characterized with good accuracy as resulting from the superposition of four flat walls in isolation. As a consequence, we find that parametrizations based on the hydraulic diameter concept, and modifications thereof, are successful in predicting the duct friction coefficient.
Plate tectonic modelling: review and perspectives
Authors: VÉRARD CHRISTIAN 
Published: February 2018

AbstractSince the 1970s, numerous global plate tectonic models have been proposed to reconstruct the Earth's evolution through deep time. The reconstructions have proven immensely useful for the scientific community. However, we are now at a time when plate tectonic models must take a new step forward. There are two types of reconstructions: those using a ‘single control’ approach and those with a ‘dual control’ approach. Models using the ‘single control’ approach compile quantitative and/or semi-quantitative data from the present-day world and transfer them to the chosen time slices back in time. The reconstructions focus therefore on the position of tectonic elements but may ignore (partially or entirely) tectonic plates and in particular closed tectonic plate boundaries. For the readers, continents seem to float on the Earth's surface. Hence, the resulting maps look closer to what Alfred Wegener did in the early twentieth century and confuse many people, particularly the general public. With the ‘dual control’ approach, not only are data from the present-day world transferred back to the chosen time slices, but closed plate tectonic boundaries are defined iteratively from one reconstruction to the next. Thus, reconstructions benefit from the wealth of the plate tectonic theory. They are physically coherent and are suited to the new frontier of global reconstruction: the coupling of plate tectonic models with other global models. A joint effort of the whole community of geosciences will surely be necessary to develop the next generation of plate tectonic models.
Seasonal forecasting of green water components and crop yield of summer crops in Serbia and Austria
Authors: Lalić B. , Firanj Sremac A. , Eitzinger J. , Stričević R. , Thaler S. , Maksimović I. , Daničić M. , Perišić D. , Dekić Lj. 
Published: February 2018

AbstractA probabilistic crop forecast based on ensembles of crop model output estimates, presented here, offers an ensemble of possible realizations and probabilistic forecasts of green water components, crop yield and green water footprints (WFs) on seasonal scales for selected summer crops. The present paper presents results of an ongoing study related to the application of ensemble forecasting concepts in crop production. Seasonal forecasting of crop water use indicators (evapotranspiration (ET), water productivity, green WF) and yield of rainfed summer crops (maize, spring barley and sunflower), was performed using the AquaCrop model and ensemble weather forecast, provided by The European Centre for Medium-range Weather Forecast. The ensemble of estimates obtained was tested with observation-based simulations to assess the ability of seasonal weather forecasts to ensure that accuracy of the simulation results was the same as for those obtained using observed weather data. Best results are obtained for ensemble forecast for yield, ET, water productivity and green WF for sunflower in Novi Sad (Serbia) and maize in Groß-Enzersdorf (Austria) – average root mean square error (2006–2014) was <10% of observation-based values of selected variables. For variables yielding a probability distribution, capacity to reflect the distribution from which their outcomes will be drawn was tested using an Ignorance score. Average Ignorance score, for all locations, crops and variables varied from 1.49 (spring barley ET in Groß-Enzersdorf) to 3.35 (sunflower water productivity in Groß-Enzersdorf).
Crowding in the first intermediate host does not affect infection probability in the second host in two helminths
Authors: Benesh D.P. 
Published: February 2018

AbstractWhen many worms co-infect the same host, their average size is often reduced. This negative density-dependent growth is called the crowding effect. Crowding has been reported many times for worms in their intermediate hosts, but rarely have the fitness consequences of crowding been examined. This study tested whether larval crowding reduces establishment success in the next host for two parasites with complex life cycles, the nematodeCamallanus lacustrisand the cestodeSchistocephalus solidus. Infected copepods, the first host, were fed to sticklebacks, the second host. Fish received a constant dose, but the infection intensity in copepods was varied (e.g. giving two singly infected copepods or one doubly infected copepod). Worms from higher-intensity infections did not have significantly reduced infection success in fish. However, crowded treatments had a disproportionate number of low and high infection rates, and although this trend was not significant, it hints at the possibility that multiple worms within a copepod are more likely to either all infect or all die when transmitted to the next host. These results indicate that a smaller larval size due to crowding need not reduce the establishment probability of a worm in the next host.
The impact of parasites during range expansion of an invasive gecko
Authors: Barnett Louise K. , Phillips Ben L. , Heath Allen C. G. , Coates Andrew , Hoskin Conrad J. 
Published: February 2018

AbstractHost–parasite dynamics can play a fundamental role in both the establishment success of invasive species and their impact on native wildlife. The net impact of parasites depends on their capacity to switch effectively between native and invasive hosts. Here we explore host-switching, spatial patterns and simple fitness measures in a slow-expanding invasion: the invasion of Asian house geckos (Hemidactylus frenatus) from urban areas into bushland in Northeast Australia. In bushland close to urban edges,H. frenatusco-occurs with, and at many sites now greatly out-numbers, native geckos. We measured prevalence and intensity ofGeckobiamites (introduced withH. frenatus), andWaddycephalus(a native pentastome). We recorded a new invasive mite species, and several new host associations for native mites and geckos, but we found no evidence of mite transmission between native and invasive geckos. In contrast, nativeWaddycephalusnymphs were commonly present inH. frenatus, demonstrating this parasite's capacity to utilizeH. frenatusas a novel host. Prevalence of mites onH. frenatusdecreased with distance from the urban edge, suggesting parasite release towards the invasion front; however, we found no evidence that mites affectH. frenatusbody condition or lifespan.Waddycephaluswas present at low prevalence in bushland sites and, although its presence did not affect host body condition, our data suggest that it may reduce host survival. The high relative density ofH. frenatusat our sites, and their capacity to harbourWaddycephalus, suggests that there may be impacts on native geckos and snakes through parasite spillback.
Differential neural reward mechanisms in treatment-responsive and treatment-resistant schizophrenia
Authors: Vanes Lucy D. , Mouchlianitis Elias , Collier Tracy , Averbeck Bruno B. , Shergill Sukhi S. 
Published: February 2018

AbstractBackgroundThe significant proportion of schizophrenia patients refractory to treatment, primarily directed at the dopamine system, suggests that multiple mechanisms may underlie psychotic symptoms. Reinforcement learning tasks have been employed in schizophrenia to assess dopaminergic functioning and reward processing, but these have not directly compared groups of treatment-refractory and non-refractory patients.MethodsIn the current functional magnetic resonance imaging study, 21 patients with treatment-resistant schizophrenia (TRS), 21 patients with non-treatment-resistant schizophrenia (NTR), and 24 healthy controls (HC) performed a probabilistic reinforcement learning task, utilizing emotionally valenced face stimuli which elicit a social bias toward happy faces. Behavior was characterized with a reinforcement learning model. Trial-wise reward prediction error (RPE)-related neural activation and the differential impact of emotional bias on these reward signals were compared between groups.ResultsPatients showed impaired reinforcement learning relative to controls, while all groups demonstrated an emotional bias favoring happy faces. The pattern of RPE signaling was similar in the HC and TRS groups, whereas NTR patients showed significant attenuation of RPE-related activation in striatal, thalamic, precentral, parietal, and cerebellar regions. TRS patients, but not NTR patients, showed a positive relationship between emotional bias and RPE signal during negative feedback in bilateral thalamus and caudate.ConclusionTRS can be dissociated from NTR on the basis of a different neural mechanism underlying reinforcement learning. The data support the hypothesis that a favorable response to antipsychotic treatment is contingent on dopaminergic dysfunction, characterized by aberrant RPE signaling, whereas treatment resistance may be characterized by an abnormality of a non-dopaminergic mechanism – a glutamatergic mechanism would be a possible candidate.
Text analytics APIs, Part 1: The bigger players
Authors: DALE ROBERT 
Published: February 2018

AbstractIf you’re in the market for an off-the-shelf text analytics API, you have a lot of options. You can choose to go with a major player in the software world, for whom each AI-related service is just another entry in their vast catalogues of tools, or you can go for a smaller provider that focusses on text analytics as their core business. In this first of two related posts, we look at what the most prominent software giants have to offer today.