bluuebunny/crossref_metadata_2025 huggingface dataset:
Extra pure tellurium oxide for the growth of high quality paratellurite crystals
Authors: Grishechkin Mikhail , Islam Anika , Khomyakov Andrew , Zykova Marina , Mozhevitina Elena , Avetisov Roman , Ermochenkov Ivan , Avetissov Igor
Published: November 2019

Tellurium oxide (IV) single crystals are in demand materials for manufacturing acousto-optical devices optical fibers for IR wavelength range. The initial material for production of active and passive optical materials must have purity better than 99.999 wt% and extremely low concentration of the residual water. The main method of synthesis of TeO2 is oxidation in nitric acid followed by recrystallization from HCl is complicated, also amount of used high purity acids and waste are very high. Besides the residual water content is no less than 10 ppm. In the research we have developed the procedure for the synthesis of high-purity tellurium (IV) oxide without the usage of liquid oxidants. The process of oxidation of elementary Te was carried out in a flowing quartz glass reactor. Air oxygen was used as an oxidizing agent. The oxidation was conducted at 600-670°C during 24 hours. The produced material was a fine crystalline powder of acicular dendritic crystals of bright white color, identified as β-TeO2 due to X-ray. It was as pure as 5N7 due to ICP-MS. The β-TeO2 crystal grown form the synthesized water-free preparation has demonstrated better optical properties towards the crystals grown from commercial TeO2, produced by the «wet» technology.
Structure and mechanical properties of ZrO2-MgO composites with bimodal pore structure
Authors: Buyakov A , Buyakova S , Kulkov S
Published: November 2019

Porous ceramic ZrO2-MgO composite in a wide range of component content was studied. The effect of content and sintering parameters on pores size, its distribution, lattice structure, coherently diffracting domains and lattice microdistortion, tensile strength was investigated. It has been shown that the adding of pore-forming particles into the initial powder makes it possible to obtain a bimodal pore structure of composites. Sintering time and MgO content in ceramics are stipulated a changing of the average size of macro- and micropores and microstresses, which determine the macroscopic strength of the material.
Investigation of mechanical properties of porous alumina ceramics: experiment and simulation
Authors: Mikushina V A , Smolin I Yu , Kulkov A S
Published: November 2019

The paper presents the experimental data on elastic and strength characteristics of specimens made of porous Al2O3 ceramics in three-point bending. Ceramics specimens were prepared by the slurry casting of commercially pure Al2O3 powder and subsequent sintering at the temperatures 1400, 1500, and 1600 °C. The simulation results were reported for the mechanical behaviour of specimens of porous Al2O3-based ceramics at the mesolevel. We studied the mesovolumes with an explicit treatment of pores loaded in uniaxial tension. The pore structure of the mesovolumes was borrowed from experimental SEM images. The mesoscopic fracture was described using the fracture criterion which includes the Lode parameter to make allowance for the stress state type. Despite wide scatter, the experimental and calculated elastic and strength characteristics of the material agree rather well.
Surface Modification Innovation for Wear Resistance Increasing
Authors: Kovács Tünde Anna , Mhatre Umesh , Nyikes Zoltán , Enikő Bitay
Published: November 2019

The surface modification is a suitable technology to increase the surface wear resistance of steels. In this way, the used substrate metal can be a low alloyed, cost-effective chemical composition steel. After the substrate metal heat treating, hardening and annealing, it needs surface modification.

It well knew some surface heat treating technologies, like carburizing, nitridation, nitrocarburizing, and surface quenching. The surface coating is also very useful technologies when by the chemical or physical process it built a new layer on the surface.

In this work, we compare different modification processes results made by the way of the traditional and new technologies advantages. The chemical composition and the structure determine the surface mechanically and wear resistance properties. The available chemical composition determines the surface modification technology [1-3].

It was prepared with different surface layers on the same substrate steel by a different process and inspected by different testing methods. On the base of the tests results needs to specification a new surface modification process for the high-level surface resistance layer.
Investigation of structures and properties of oxide-hydroxide systems after mechanical activation
Authors: Levkov R V , Kulkov S N
Published: November 2019

It has been studied Al2O3 and ZrO2 with Al(OH)3mixtures after mechanical activation in a planetary ball mill.Measurement of the specific surface by the BET method has shown that an increase of mechanical treatment time leads to an increase in the specific surface in all studied powders. In the initial states a large agglomerate of the order of 50-150 μm and isolated particles of 0.05-0.1 μm were observed. Mechanical treatment leads to fracture of agglomerates into separate particles. It has been revealed that the amount of agglomerates decreased with the increasing of the mechanical activation time, and the number of isolated particles increased. The average size of the agglomerates of Al-based powders varies in the range of 50-15 μm. In the case of powders based on ZrO2, it varies in the range of 10-14 μm.
Hypersound excitation of three-layer magnetic film by microwave field
Authors: Kotov L N , Dianov M Yu , Vlasov V S , Ustyugov V A , Shilov S V
Published: November 2019

The work deals with the definition of elastic and magnetic oscillations exited by microwave magnetic field in the three-layer structure. The frequency dependences for the amplitudes of the magnetic and elastic vibrations of the film layers with different values of the material parameters and amplitudes of the external fields are calculated.
Amorphous iron formation following occupancy of iron atoms in vacant sites of epsilon-iron that transformed from alpha-iron during rubbing in a low vacuum
Authors: Furuichi H
Published: November 2019

The main purpose of this paper is to present two TEM diffraction patterns taken from a layer (more than 100 μm thick) of piled-up adhered wear debris on a rubbed surface. The unidirectional rubbing was made in a low vacuum, regularly separating the slider from the specimen. The specimen and the slider were α-iron. One of the diffraction patterns consists of large spots and halo rings and the other consists of small faint spots and halo rings. The latter seems to be the state just before the perfect amorphization. All the spots in the diffraction patterns correspond to the structure formed due to the occupancy of iron atoms in O and T sites of ε-iron. Neither this way of amorphization nor the occupied structure mentioned above has not been reported. Both the amorphous state and the occupied structure remain at ambient conditions. The mechanism of high-pressure generation that transformed α-iron to ε-iron and the generation of high tensile stress that breaks the atomic bonds in wear debris are presented. The latter is considered to have enabled the occupancy.
Damage of thin-walled box beams with omega cross-section joined by adhesive layers subjected to bending deformation process
Authors: Sadowski T , Nowicki M.
Published: November 2019

The subject of this study is aluminum box beams of omega cross-section, consisting of an omega profile and connected to the metal by the adhesive interface of the area 120 cm2. In the laboratory tests were used specimens made from 7075 aluminum with dimensions 300 × 84 × 36 mm. To connect the components of the specimens an adhesive layer Loctite 9545 was used.

The samples were subjected to 3-point bending (3-PB). Laboratory tests were conducted using a MTS (25kN) and a Digital Image Correlation (DIC) system, in order to accurately determine states of deformation of the box beams. With the load increase the profiles deform elastically at the beginning and then in the final stage of deformation process, a collapse of the side walls and local plastic deformation occured. This causes a sudden drop of the load capacity of the entire profile.

To complete the experimental analysis, the numerical model of the thin-walled box beam was created. The model allows for observation of stress and displacement fields variation in the bending element, as well as places of their concentration. Moreover, a detailed analysis of damage growth and the final destruction of the connecting elements associated with the load increase was performed. Numerical simulations were done using ABAQUS code. The FEM analysis results confirm correctness of the assumptions in the numerical model and allow for a more detailed description of the process decohesion adhesive layer and the damage of aluminium elements of the thin-walled box beams.
Examination of the utilization of aluminum dross in road construction
Authors: Udvardi Bella , Géber Róbert , Kocserha István
Published: November 2019

Aluminum dross is a recyclable by-product of the aluminum manufacturing process. Since the use of aluminum alloys increased in large quantities, which cause a significant amount of aluminum dross produced, therefore, the need for alternative solutions are also increased. The goal of this study is to investigate the utilization possibility of dross as an alternative asphalt filler. During the research aluminum dross and limestone (as reference material), which is well-known filler in asphalt technology, were investigated. Different tests were done on the samples: specific gravity, particle size distribution, BET specific surface area and Rigden voids were determined on the fillers. Scanning electron microscope was used to characterize the morphological features of fillers. To reveal the affinity of fillers to bitumen hydrophilic/hydrophobic properties and oil adsorption ability were also investigated. These examinations help to better to understand the interaction between fillers and binder material. With the use of fillers asphalt mixtures and specimens were also prepared for stiffness tests and asphalt cracking temperature tests. The results show a good correlation between dross and limestone fillers, therefore aluminum dross may be an alternative to partly substitute limestone filler.
Fracture Toughness of Silicon Nitride Measured by the Surface Crack in Flexure (SCF) Test Method
Authors: Nindhia T G T , Lube Tanja
Published: November 2019

The surface crack in flexure (SCF) is a method for the evaluation of the fracture toughness of advanced ceramics. Conventionally is practiced by using a Knoop indenter to make a very small pre-crack. Removal on indent and the plastically deformed zone is required before the fracture test. The purpose of this removal is to eliminate residual stresses under the Knoop impression and to obtain a semi elliptical pre-crack shape. In this work fracture toughness values by the SCF method are compared with those measured using the SEVNB (single edge V-notched beam) method. The material chosen for this purpose was gas pressured sintered silicon nitride (Si3N4) containing 3wt. % Al2O3 and 3 wt. % Y2O3 (SL200B, Ceram Tec, Plochingen, Germany). The varied parameters the amount of material removed from the surface. Short specimens with size 3 x 4 x >25 mm were prepared for this purpose. The fracture toughness of specimens with a surface removal in the range suggested from ASTM C 1421 were found to agree with the results obtained from SEVNB. A surface removal below the recommendation resulted in low values of fracture toughness. Increasing the amount of surface removal moderately was found to still fit with results obtained from SEVNB. Surface removal of much more from the recommended amount leads to failure from natural flaws.
Evaluation Wettability of nanofluid on the Surface of Zircalloy 4 Before and after Oxidation
Authors: Prajitno Djoko Hadi , Trisnawan Very , Sitorus Jupiter Pane
Published: November 2019

The solid surface tension plays an important role in the heat and mass transfer system for heat exchanger equipment. In the nuclear power plant industry, Zircalloy 4 has been used for long time as structure materials. The purpose of the experimental is to study solid state surface tension behavior by measure contact angle of aquades and Nano fluid contain nano particle alumina on metal surface of Zircalloy 4 before and after oxidation at 700°C by sessile drop method. The experiment is to measure the static contact angle and drop of aquades and nano fluid contains nano particle alumina on zircalloy 4 with different spreading time from 1 to 30 minute. It was observed that zircalloy 4 after oxidation lose their hydrophobic properties with increasing elapsed time during drop of a aquades and nano fluid on the surface of alloy compared with zircalloy 4 before oxidation. As a result the contact angle of aquades and nano fluid on surface of zircalloy 4 before and after oxidation is decrease grdually during increasing elapsed time. While the magnitude diameter drops of aquades and nano fluid and wetting surface are increase with increasing elapsed time on the surface of Zircalloy 4 before and after oxidation. It was observed that oxidised zircalloy4 good wettability properties compare with non oxidised zircaloy 4.
rGO based photo-anode in dye-sensitized solar cells (DSSC) and its photovoltaic characteristics
Authors: Arsyad Waode Sukmawati , Pristianti Aricia , Agusu La , Hidayat Rahmat
Published: November 2019

On the attempt to increase transport properties of the photo-anode in DSSC, we synthesized rGO powder from graphite bar (commercially available) using modified Hummer’s method. The SEM-EDS results had confirmed the attachment of the rGO layer to the FTO substrate. For DSSC cells, we made two cells configuration, the first one was stacking layers of rGO and TiO2resulting configuration of TiO2/rGO/TiO2(A2) and rGO/TiO2/rGO (A3), where rGO was deposited by spin coating and TiO2was deposited by a screen printing technique. The second one, the rGO powder was mixed with TiO2paste with several ratios in weight, namely TiO2:rGO 40:1 (B1), 40:2 (B2), and 40:8 (B3) and then deposited on the FTO substrate by screen printing. The reference cell was assigned as A1 (TiO2only). From the conductivity measurement using the four-probe method, the utilization of rGO layer increased the conductivity of photoanode layer, namely (1.37, 2.9 and 6.3)x10−2Ω−1cm−1for A1 to A3 and (1.5, 2.5, and 3.7)x10−2Ω−1cm−1for B1 to B3. From the photovoltaic measurement, we found that the efficiency of the DSSC cell firstly increased with the insertion of rGO layer, from 1.8% (A1) to 4.59% (A2), and decreased to 3.22%, as the conductivity increased in A3. While for the composite of TiO2:rGO, the efficiency of the cell reduced with the increased amount of rGO, from 3.45% (B1) to 2.9% and 1.9% for B2 and B3. We found that the reduction of photovoltaic performance was affected by two main factors, specifically, direct contact between rGO and redox species in the electrolyte, which induced recombination process, and conductivity of the photo-anode layer. To fully achieve the advantage of rGO utilization in photo-anode, once must be considered was the use of protection layer on top of the rGO layer to avoid direct contact between the rGO/electrolyte interface.
Synthesis and Characterization of Gadolinium doped Cerium (Ce0,9Gd0,1O1,95) by using Various Carbonates as a Precipitant
Authors: Hapsari Ade Utami , Raharjo Jarot , Yuliani Hanif , Agung Suradharmika I.G. , Damisih  , Pravitasari Retna Deca , Sari Desiana P.
Published: November 2019

Gadolinium-doped cerium (Ce0.9Gd0.1O1.95, GDC) as an electrolyte in IT-SOFC has higher performance in nano-sized than the other sized. Carbonate was known as a precipitant agent that could affect the morphology and size of the particle. In this study, the effects of various carbonates as a precipitant agent on the synthesis of GDC by co-precipitation method were investigated. Cerium in the form of Ce(NO3)3.6H2O (cerium nitrate hexahydrate) used in the synthesis process. Three types of carbonates, i.e. ammonium carbonate, potassium carbonate, and sodium hydrogen carbonate, namely GDC1, GDC2, and GDC3, respectively, was used as a precipitating agent. The GDC powder resulted was then characterized by X-Ray Diffraction (XRD), Fourier Transform Infra Red (FTIR), Particle Size Analysis (PSA), and Scanning Electron Microscopy (SEM). The carbonates variation affected the physical properties and the formed particle of GDC. GDC2 showed the optimum carbonate that produces electrolyte GDC with better properties as an IT-SOFC electrolyte based on physical properties.
Polyethylene Glycol Addition as Non-ionic Surfactant in Water-based Carbon Microfluid for Quench Medium in Heat Treatment Process
Authors: Rakhman D. , Putra W. N. , Ramadhani C. A. , Harjanto S.
Published: November 2019

The mechanical properties of a material depend on the quenching process. In this process, there is a rapid cooling from elevated to room temperature in a short time by using a quench medium. Therefore, the phase transformation from austenite to martensite occurs. The common medium used in the quenching process is water, oil, polymer, and gas. Nanofluids are started to be used as a quench medium because they offer better thermal conductivity compared with the conventional medium. Selection of carbon-based nanofluids as a quenching process medium aims to obtain high thermal conductivity values and controllable cooling rates. Thereby, the expected microstructure of the material could be relatively easier to form. In this paper, carbon particles were obtained using a top-down method with a planetary ball mill for 15 hours at 500 rpm. Based on the electron microscope and spectroscopy results, the particle dimension was average at 15 μm after milling, and the carbon purity of the powder used in this research was 99%. Carbon particles at 0.1%, 0.3%, and 0.5% with variation of non-ionic surfactant Polyethylene Glycol of 1%, 2%, 3%, 4% and 5% respectively was used in this research. AISI 1045 or JIS S45C carbon steel was used as a steel sample, and austenized at 1000°C for 1 hour and then quenched in the microfluid. The hardness obtained was up to 811 HV for the sample quenched in 0.5% carbon and 1% Polyethylene Glycol. The improvement was more than 100 HV, compared with the sample quenched in distilled water, which had a hardness only 666 HV.
Ionic Liquids (ILs)-based Electrolytes System for Lithium Ion Batteries
Authors: Nandika Astrid. O. , Rochliadi Achmad , Patah Aep
Published: November 2019

Electrolytes system plays an important part in Lithium Ion Batteries (LIBs) due to its role in lithium ion (Li+) transport between anode and cathode. Commercial LIBs use organic carbonates-based electrolytes system, but these electrolytes are flammable and volatile. For these reasons, replacement with non-flammable, non-volatile and high conductive compounds become recent research focus. Owing to the excellent properties, ILs are expected to cover the limitation of the organic-based electrolytes system in LIBs. The conductivity of electrolytes system which consists of dimethyl carbonate (DMC)/diethyl carbonate (DEC) (1:1, v/v) as organic solvent (OS) and imidazolium-based ILs is measured at various temperatures. Furthermore, the thermal stability of the electrolytes and the redox properties of lithium ion in IL-based electrolytes system are also investigated. [bmim][BF4]-based electrolyte yields a conductivity of ~13 mS cm−1at 20 °C which is 10,000 times higher than DMC/DEC based only. Thermal analysis shows that the IL-based electrolytes decompose at 360 °C, much higher than the organic-based only (∼110 °C). Cyclic voltammetry measurement of the ILs-based electrolytes with [bmim][BF4] : DEC: DMC (3:1:1) + LiBF40.2 M compositions displays reversible redox reaction. The presence of [bmim][BF4] affects the redox reaction of Li+ ion, in both current and potential. Based on these results, a mixture of ILs and organic solvent has a potential as a new electrolytes system in the next LIBs.
Characteristics of Corncob-Originated Activated Carbon Using Two Different Chemical Agent
Authors: Rahma Nur Aini , Kurniasari Asih , Setyo Pambudi Yoyok Dwi , Bintang His Muhammad , Zulfia Anne , Hudaya Chairul
Published: November 2019

The research and development of biomass-based activated carbon (AC) has attracted much attention from researchers due to the abundant resource of biomass, including corncob waste. The urgency to find alternative and innovative applications for simple, inexpensive carbon material can be obtained by synthesizing the corncob waste which is abundant renewable resource and suitable for carbon properties. The use of chemical agent during activation process is of important to produce the desired AC, including high surface area and excellent electrical conductivity. Among the various chemical agents, KOH and ZnCl2 have been widely applied for synthesizing AC. This study aims to find out the characteristics of corncob-originated activated carbon (CAC) using these two chemical agents. Step by step of activating carbon from corncob will be determined briefly. Corncob was dried and chopped. Then it was carbonized. After that, the carbon result was soaked in each chemical agent solution, KOH and ZnCl2, in different molarity for carbon chemical activation. For physical activation, impregnated carbon was carbonized again in high temperature under inert gas atmosphere until AC was obtained. We employed scanning electron microscopy (SEM), X-Ray diffraction (XRD), and Raman Spectroscopy measurement to characterize the CAC samples. The results showed that the application of KOH and ZnCl2 at a different optimized process parameters exhibited the different results of surface morphology, structures, and crystallyte size. The crystallite size of the activated carbon using different chemical activating agents with varied concentrations is diverse enough. The XRD data revealed the average crystallite size of carbon with KOH as the activator is ∼45 nm in three different conditions. However, in the case of ZnCl2 as the activating agent, it shows the average size of ∼65 nm. This number is significantly higher than the activated carbon impregnated with KOH . Visual observation of SEM images gives an impression on the carbon pore where CACK12 posess the highest pores among those analytes. The synthesized corncob activated carbon can be used in many functional application such as energy storage materials, agriculture, and adsorbents in industrial and environmental sectors.
Development of an Asthma-Specific Job Exposure Matrix for Use in the United States
Authors: Henneberger Paul K , Kurth Laura M , Doney Brent , Liang Xiaoming , Andersson Eva
Published: November 2019

Introduction

Existing asthma-specific job-exposure matrices (JEMs) do not necessarily reflect current working conditions in the USA and do not directly function with occupational coding systems commonly used in the USA. We initiated a project to modify an existing JEM to address these limitations, and to apply the new JEM to the entire US employed population to estimate quantitatively the extent of probable work-related asthma exposures nationwide.

Methods

We started with an asthma-specific JEM that was developed for northern Europe (the N-JEM) and modified it to function with the 2010 US Standard Occupational Classification (SOC-2010) codes and to reflect working conditions in the USA during the post-2000 period. This involved cross walking from the 1988 International Standard Classification of Occupations (ISCO-88) codes used in the N-JEM to the SOC-2010 codes, transferring the N-JEM exposure assignments to the SOC-2010 codes, and modifying those assignments to reflect working conditions in the USA. The new US asthma JEM (USA-JEM) assigns exposures to 19 agents organized into five categories. The USA-JEM and N-JEM were applied to the same sample of working adults with asthma to compare how they performed, and the USA-JEM was also applied to the entire 2015 US working population to estimate the extent of occupational asthma exposures nationally.

Results

The USA-JEM assigns at least one asthma-related probable exposure to 47.5% and at least one possible exposure to 14.9% of the 840 SOC-2010 detailed occupations, and 9.0% of the occupations have both probable exposure to at least one agent and possible exposure to at least one other agent. The USA-JEM has greater sensitivity for cleaning products, highly reactive disinfectants and sterilants, and irritant peak exposures than the N-JEM. When applied to the entire 2015 US working population, the USA-JEM determined that 42.6% of workers had probable exposure to at least one type of occupational asthma agent.

Discussion

A new asthma-specific JEM for application in the USA was developed. Additional work is needed to compare its performance to similar JEMs and, if possible, to exposure assessments generated on a case-by-case basis.
Nest association between two predators as a behavioral response to the low density of rodents
Authors: Pokrovsky Ivan , Ehrich Dorothée , Fufachev Ivan , Ims Rolf A , Kulikova Olga , Sokolov Aleksandr , Sokolova Natalia , Sokolov Vasiliy , Yoccoz Nigel G
Published: November 2019

Many birds nest in association with aggressive birds of other species to benefit from their protection against predators. We hypothesized that the protective effect also could extend to foraging resources, whereby the resultant resource-enriched habitats near a nest of aggressive raptors could be an alternative cause of associations between nesting bird species with non-overlapping foraging niches. In the Arctic, the Rough-legged Hawk (Buteo lagopus) and the Peregrine Falcon (Falco peregrinus) are 2 raptor species with non-overlapping food resources that have been reported to nest sometimes in close proximity. Since nesting Peregrine Falcons are very aggressive, they may protect the small rodent prey near their nests from predation, and Rough-legged Hawks could use these hot spots as a nesting territory. In 2 regions in low Arctic Russia we found that (1) the nesting territories of Peregrine Falcons were indeed enriched with small rodents as compared to control areas, (2) the probability of nest association between the 2 raptors increased when rodent abundance was generally low in the region where hawks did not use alternative prey, and (3) hawk reproductive success increased when nesting close to Peregrine Falcons. These results suggest that implications of aggressive nest site defense in birds in certain cases may involve more mechanisms than previously explored. A key ecological process in tundra, rodent population cycles, may explain the occurrence and adaptive significance of a specific behavior pattern, the nesting association between 2 raptor species.
Affiliation history and age similarity predict alliance formation in adult male bottlenose dolphins
Authors: Gerber Livia , Connor Richard C , King Stephanie L , Allen Simon J , Wittwer Samuel , Bizzozzero Manuela R , Friedman Whitney R , Kalberer Stephanie , Sherwin William B , Wild Sonja , Willems Erik P , Krützen Michael
Published: November 2019

Male alliances are an intriguing phenomenon in the context of reproduction since, in most taxa, males compete over an indivisible resource, female fertilization. Adult male bottlenose dolphins (Tursiops aduncus) in Shark Bay, Western Australia, form long-term, multilevel alliances to sequester estrus females. These alliances are therefore critical to male reproductive success. Yet, the long-term processes leading to the formation of such complex social bonds are still poorly understood. To identify the criteria by which male dolphins form social bonds with other males, we adopted a long-term approach by investigating the ontogeny of alliance formation. We followed the individual careers of 59 males for 14 years while they transitioned from adolescence (8–14 years of age) to adulthood (15–21 years old). Analyzing their genetic relationships and social associations in both age groups, we found that the vast majority of social bonds present in adolescence persisted through time. Male associations in early life predict alliance partners as adults. Kinship patterns explained associations during adolescence but not during adulthood. Instead, adult males associated with males of similar age. Our findings suggest that social bonds among peers, rather than kinship, play a central role in the development of adult male polyadic cooperation in dolphins.
A taxonomic survey of monocotylar Apiaceae and the implications of their morphological diversity for their systematics and evolution
Authors: Kljuykov Eugene V , Petrova Svetlana E , Degtjareva Galina V , Zakharova Ekaterina A , Samigullin Tahir H , Tilney Patricia M
Published: November 2019

In Apiaceae, embryos of most species have two cotyledons, but some species are consistently monocotylar. Traditionally, the monocotyly has been considered as taxonomically important at the generic level, despite its presumably multiple origins in the family. In this study, a survey of the published literature and our new findings on cotyledon number, embryo and seedling morphology and nrDNA ITS sequence data are presented to provide modern insights into the taxonomic distribution and phylogenetic relationships of monocotylar taxa. A molecular phylogenetic tree representing much of the diversity of monocotylar Apiaceae was produced to re-evaluate the potential implication of monocotyly for systematics and to elucidate its evolutionary significance in the family. Our data document the presence of monocotylar seedlings in 59 species representing 15 genera, in three species and one genus (Postiella) of which monocotylar seedlings are reported for the first time. Analysis of ITS sequence data indicates that monocotyly in Apiaceae has arisen independently in at least seven different lineages encompassing five of 41 major clades of subfamily Apioideae, but not in early-diverging lineages. Parallel evolution has resulted in a remarkable morphological similarity in monocotylar embryo and seedling organization, especially in the proportion of the cotyledon length to the axis of the embryo and the multifunctional cotyledonary tube in the seedling. These features could be considered as adaptations to a geophilic life form, as all monocotylar species are perennial herbs with tuberous underground organs distributed mainly in the Ancient Mediterranean region. The single cotyledon in Apiaceae, as in most other monocotyledonous eudicots, could be interpreted as two united cotyledons (syncotyly), but further developmental studies are needed to test this hypothesis.
Postoperative delirium is associated with increased plasma neurofilament light
Authors: Casey Cameron P , Lindroth Heidi , Mohanty Rosaleena , Farahbakhsh Zahra , Ballweg Tyler , Twadell Sarah , Miller Samantha , Krause Bryan , Prabhakaran Vivek , Blennow Kaj , Zetterberg Henrik , Sanders Robert D
Published: November 2019

While delirium is associated with cognitive decline and dementia, there is limited evidence to support causality for this relationship. Clarification of how delirium may cause cognitive decline, perhaps through evidence of contemporaneous neuronal injury, would enhance plausibility for a causal relationship. Dose-dependence of neuronal injury with delirium severity would further enhance the biological plausibility for this relationship. We tested whether delirium is associated with neuronal injury in 114 surgical patients recruited to a prospective biomarker cohort study. Patients underwent perioperative testing for changes in neurofilament light, a neuronal injury biomarker, as well as a panel of 10 cytokines, with contemporaneous assessment of delirium severity and incidence. A subset of patients underwent preoperative MRI. Initially we confirmed prior reports that neurofilament light levels correlated with markers of neurodegeneration [hippocampal volume (ΔR2 = 0.129, P = 0.015)] and white matter changes including fractional anisotropy of white matter (ΔR2 = 0.417, P < 0.001) with similar effects on mean, axial and radial diffusivity) in our cohort and that surgery was associated with increasing neurofilament light from preoperative levels [mean difference (95% confidence interval, CI) = 0.240 (0.178, 0.301) log10 (pg/ml), P < 0.001], suggesting putative neuronal injury. Next, we tested the relationship with delirium. Neurofilament light rose more sharply in participants with delirium compared to non-sufferers [mean difference (95% CI) = 0.251 (0.136, 0.367) log10 (pg/ml), P < 0.001]. This relationship showed dose-dependence, such that neurofilament light rose proportionately to delirium severity (ΔR2 = 0.199, P < 0.001). Given that inflammation is considered an important driver of postoperative delirium, next we tested whether neurofilament light, as a potential marker of neurotoxicity, may contribute to the pathogenesis of delirium independent of inflammation. From a panel of 10 cytokines, the pro-inflammatory cytokine IL-8 exhibited a strong correlation with delirium severity (ΔR2 = 0.208, P < 0.001). Therefore, we tested whether the change in neurofilament light contributed to delirium severity independent of IL-8. Neurofilament light was independently associated with delirium severity after adjusting for the change in inflammation (ΔR2 = 0.040, P = 0.038). These data suggest delirium is associated with exaggerated increases in neurofilament light and that this putative neurotoxicity may contribute to the pathogenesis of delirium itself, independent of changes in inflammation.
Clinicopathological correlations of sural nerve biopsies in TTR Val30Met familial amyloid polyneuropathy
Authors: Fernandes Armindo , Coelho Teresa , Rodrigues Aurora , Felgueiras Helena , Oliveira Pedro , Guimarães António , Melo-Pires Manuel , Taipa Ricardo
Published: November 2019

Familial amyloid polyneuropathy with the substitution of methionine for valine at position 30 in the TTR gene is the most common type of hereditary transthyretin amyloidosis. Although several authors have previously reported a size-dependent fibre loss, predominantly involving unmyelinated and small-diameter myelinated fibres, the mechanisms of nerve fibre loss have not been fully understood. In this study, we establish the morphometric pattern of peripheral neuropathy in patients with familial amyloid polyneuropathy and asymptomatic mutation carriers in the biopsies from our archive and correlated the pathological findings with clinical features. A total of 98 patients with familial amyloid polyneuropathy and 37 asymptomatic mutation carriers (TTR Val30Met mutation), aged between 17 and 84 years, who underwent sural nerve biopsy between 1981 and 2017 at Centro Hospitalar Universitário do Porto were studied. Thirty-one controls were included for comparison. The median age at nerve biopsy was 26.0 [interquartile range = 23.5–39.5] years for asymptomatic mutation carriers, 45.0 [35.0–60.0] years for patients with familial amyloid polyneuropathy and 44.0 [30.0–63.0] years for controls. The median duration between nerve biopsy and symptoms’ onset was 7.0 [3.3–11.8] years (range: 1–27 years) in the asymptomatic carriers. Most patients were in an earlier disease stage (93% with a polyneuropathy disability scale ≤2). Patients had loss of small and myelinated fibres compared with both asymptomatic carriers and controls (P < 0.001), whereas asymptomatic carriers showed loss of small myelinated fibres when compared with controls (P < 0.05). The loss of myelinated fibres increased with disease progression (P < 0.001), and patients in more advanced clinical stage showed more frequent amyloid deposition in the nerve (P = 0.001). There was a positive correlation between large myelinated fibre density and time to symptoms’ onset in the asymptomatic carriers that developed early-onset form of the disease (r = 0.52, P < 0.01). In addition, asymptomatic carriers with amyloid deposition already present in sural nerve biopsies developed symptoms earlier than those with no amyloid (P < 0.01). In conclusion, this study confirms that the loss of small fibre size is an initial event in familial amyloid polyneuropathy, already present in asymptomatic gene carriers, starting several years before the onset of symptoms. We show for the first time that large myelinated fibres’ loss and amyloid deposition are pathological features that correlate independently with short period to the onset of symptoms for asymptomatic carriers that developed early-onset form of the disease. These findings are therapeutically relevant, as it would allow for a better interpretation of the role of disease-modifying agents in transthyretin familial amyloid polyneuropathy.
Host Plant and Thermal Stress Induce Supernumerary Instars in Caterpillars
Authors: Abarca Mariana , Lill John T , Weiss Martha R
Published: November 2019

Environmental stressors may induce variation in the number of larval instars of holometabolous insects. Host plant quality and ambient temperature can both induce this life history shift in the silver-spotted skipper, Epargyreus clarus (Cramer 1775) (Lepidoptera: Hesperiidae). To better understand this phenomenon, we raised larvae on high-quality (kudzu) or low-quality (wisteria) host plants in growth chambers under three temperature regimes (20, 26, and 32°C) that were either constant or diurnally fluctuating (T ± 5°C), and recorded survival and incidence of supernumerary instars. Larvae feeding on the low-quality host and/or experiencing thermal stress were more likely to show supernumerary development (SD). A subset of treatments yielded a mix of SD and TD (typical development) individuals, allowing for comparisons between phenotypes. Under the most stressful treatment (20 ± 5°C, wisteria), development time was 9 days longer in SD than in TD individuals; by contrast, at typical summer temperatures (26 ± 5°C), also on wisteria, total development time did not differ between these two phenotypes. Head capsules of both second and third instars were smaller in SD individuals. A retrospective logistic regression analysis indicated that third-instar head capsule size could be used to predict expression of the SD phenotype. By the ultimate instar, however, there were no detectable differences in head capsule size, and SD and TD individuals did not differ in pupal mass, strongly suggesting that the SD phenotype functions as a compensatory mechanism allowing E. clarus larvae to achieve the same size at metamorphosis (a strong fitness correlate) as TD larvae.
Chromosomal-level reference genome of Chinese peacock butterfly (Papilio bianor) based on third-generation DNA sequencing and Hi-C analysis
Authors: Lu Sihan , Yang Jie , Dai Xuelei , Xie Feiang , He Jinwu , Dong Zhiwei , Mao Junlai , Liu Guichun , Chang Zhou , Zhao Ruoping , Wan Wenting , Zhang Ru , Li Yuan , Wang Wen , Li Xueyan
Published: November 2019

Background

Papilio bianor Cramer, 1777 (commonly known as the Chinese peacock butterfly) (Insecta, Lepidoptera, Papilionidae) is a widely distributed swallowtail butterfly with a wide number of geographic populations ranging from the southeast of Russia to China, Japan, India, Vietnam, Myanmar, and Thailand. Its wing color consists of both pigmentary colored scales (black, reddish) and structural colored scales (iridescent blue or green dust). A high-quality reference genome of P. bianor is an important foundation for investigating iridescent color evolution, phylogeography, and the evolution of swallowtail butterflies.

Findings

We obtained a chromosome-level de novo genome assembly of the highly heterozygous P. bianor using long Pacific Biosciences sequencing reads and high-throughput chromosome conformation capture technology. The final assembly is 421.52 Mb on 30 chromosomes (29 autosomes and 1 Z sex chromosome) with 13.12 Mb scaffold N50. In total, 15,375 protein-coding genes and 233.09 Mb of repetitive sequences were identified. Phylogenetic analyses indicated that P. bianor separated from a common ancestor of swallowtails ~23.69–36.04 million years ago. Demographic history suggested that the population expansion of this species from the last interglacial period to the last glacial maximum possibly resulted from its decreased natural enemies and its adaptation to climate change during the glacial period.

Conclusions

We present a high-quality chromosome-level reference genome of P. bianor using long-read single-molecule sequencing and Hi-C–based chromatin interaction maps. Our results lay the foundation for exploring the genetic basis of special biological features of P. bianor and also provide a useful data source for comparative genomics and phylogenomics among butterflies and moths.
Sigma-1 receptor is a key genetic modulator in amyotrophic lateral sclerosis
Authors: Couly Simon , Khalil Bilal , Viguier Véronique , Roussel Julien , Maurice Tangui , Liévens Jean-Charles
Published: November 2019

Sigma-1 receptor (S1R) is an endoplasmic reticulum (ER) chaperone that regulates mitochondrial respiration but also controls cellular defense against ER and oxidative stress. This makes S1R a potential therapeutic target in amyotrophic lateral sclerosis (ALS). Especially, as a missense mutation E102Q in S1R has been reported in few familial ALS cases. However, the pathogenicity of S1RE102Q and the beneficial impact of S1R in the ALS context remain to be demonstrated in vivo. To address this, we generated transgenic Drosophila that express human wild-type S1R or S1RE102Q. Expression of mutant S1R in fly neurons induces abnormal eye morphology and locomotor defects in a dose-dependent manner. This was accompanied by abnormal mitochondrial fragmentation, reduced ATP levels and a higher fatigability at the neuromuscular junction during high energy demand. Overexpressing IP3 receptor or glucose transporter mitigates the S1RE102Q-induced eye phenotype, further highlighting the role of calcium and energy metabolism in its toxicity. More importantly, we showed that wild-type S1R rescues locomotor activity and ATP levels of flies expressing the key ALS protein, TDP43. Moreover, overexpressing wild-type S1R enhances resistance of flies to oxidative stress. Therefore, our data provide the first genetic evidence that mutant S1R recapitulates ALS pathology in vivo while increasing S1R confers neuroprotection against TDP43 toxicity.
AI-Mediated Communication: Definition, Research Agenda, and Ethical Considerations
Authors: Hancock Jeffrey T , Naaman Mor , Levy Karen
Published: November 2019

We define Artificial Intelligence-Mediated Communication (AI-MC) as interpersonal communication in which an intelligent agent operates on behalf of a communicator by modifying, augmenting, or generating messages to accomplish communication goals. The recent advent of AI-MC raises new questions about how technology may shape human communication and requires re-evaluation – and potentially expansion – of many of Computer-Mediated Communication’s (CMC) key theories, frameworks, and findings. A research agenda around AI-MC should consider the design of these technologies and the psychological, linguistic, relational, policy and ethical implications of introducing AI into human–human communication. This article aims to articulate such an agenda.
Conceptual Clarity in Clinical Bioethical Analysis
Authors: Parker J Clint
Published: November 2019

Conceptual clarity is essential when engaging in dialogue to avoid unnecessary disagreement and to promote mutual understanding. In this issue devoted to clinical bioethics, the authors exemplify the virtue of careful conceptual analysis as they explore complex clinical questions regarding the essential nature of medicine, the boundaries of killing and letting die, the meaning of irreversibility in definitions of death, the argument for a right to try experimental medications, the ethical borders in complex medical billing, and the definition and modeling of complex disease states.
Aspect and Thematic Roles
Authors: Ogihara Toshiyuki
Published: November 2019

In this work, I propose a new semantic analysis of the Japanese progressive/resultative morpheme -te iru, which also leads to an improved account of the English progressive and contributes to cross-linguistic theory of aspect. The proposal is based on the modal analysis of the English progressive proposed by Portner (1998) and Ferreira (2016), but it is modified to accommodate the Japanese data. Crucially, the target state (resultative) reading of -te iru is available when the subject entity is a theme/undergoer; this is not controlled by the length of the event being described. To implement this idea, this work develops a formal system in which each thematic role predicate has its own temporal argument, and this time does not necessarily equal the temporal trace of the event in question. Specifically, a theme bears the target state role associated with an event e at a time that immediately follows the temporal trace of e. In addition, to describe and explain the behavior of -te iru, the traditional idea of “inertia worlds” according to which the relevant possible worlds are identical up to the utterance time is modified to allow them to differ in the past as well as in the future. It is noted that this modification is justified for the English progressive as well as for the Japanese -te iru form. This proposal allows us to predict that the behavior of achievements in English and Japanese is alike in simple past sentences and nominalized cases, but differs from each other in sentences containing the aspectual morphemes in question.
A proof-theoretic study of abstract termination principles
Authors: Powell Thomas
Published: November 2019

We carry out a proof-theoretic analysis of the wellfoundedness of recursive path orders in an abstract setting. We outline a general termination principle and extract from its wellfoundedness proof subrecursive bounds on the size of derivation trees that can be defined in Gödel’s system T plus bar recursion. We then carry out a complexity analysis of these terms and demonstrate how this can be applied to bound the derivational height of term rewrite systems.