bluuebunny/crossref_metadata_2025 huggingface dataset:
β‐amyloid model core peptides: Effects of hydrophobes and disulfides
Authors: Hawk Laura M. L. , Pittman Jay M. , Moore Patrick C. , Srivastava Atul K. , Zerweck Jonathan , Williams Joshua T. B. , Hawk Andrew J. , Sachleben Joseph R. , Meredith Stephen C.
Published: November 2019

The mechanism by which a disordered peptide nucleates and forms amyloid is incompletely understood. A central domain of β‐amyloid (Aβ21–30) has been proposed to have intrinsic structural propensities that guide the limited formation of structure in the process of fibrillization. In order to test this hypothesis, we examine several internal fragments of Aβ, and variants of these either cyclized or with an N‐terminal Cys. While Aβ21–30 and variants were always monomeric and unstructured (circular dichroism (CD) and nuclear magnetic resonance spectroscopy (NMRS)), we found that the addition of flanking hydrophobic residues in Aβ16–34 led to formation of typical amyloid fibrils. NMR showed no long‐range nuclear overhauser effect (nOes) in Aβ21–30, Aβ16–34, or their variants, however. Serial 1H‐15N‐heteronuclear single quantum coherence spectroscopy, 1H‐1H nuclear overhauser effect spectroscopy, and 1H‐1H total correlational spectroscopy spectra were used to follow aggregation of Aβ16–34 and Cys‐Aβ16–34 at a site‐specific level. The addition of an N‐terminal Cys residue (in Cys‐Aβ16–34) increased the rate of fibrillization which was attributable to disulfide bond formation. We propose a scheme comparing the aggregation pathways for Aβ16–34 and Cys‐Aβ16–34, according to which Cys‐Aβ16–34 dimerizes, which accelerates fibril formation. In this context, cysteine residues form a focal point that guides fibrillization, a role which, in native peptides, can be assumed by heterogeneous nucleators of aggregation.
Population Pharmacokinetics of Nivolumab in Combination With Ipilimumab in Patients With Advanced Malignancies
Authors: Zhang Jason , Sanghavi Kinjal , Shen Jun , Zhao Xiaochen , Feng Yan , Statkevich Paul , Sheng Jennifer , Roy Amit , Zhu Li
Published: November 2019

Nivolumab is a fully human monoclonal antibody that inhibits programmed cell death‐1 activation. To assess covariate effects on nivolumab clearance (CL), a population pharmacokinetics model was developed using data from 6,468 patients with colorectal cancer, hepatocellular carcinoma, melanoma, non‐small cell lung cancer, renal cell carcinoma, or small cell lung cancer who received nivolumab as monotherapy or in combination with ipilimumab or chemotherapy across 25 clinical studies. Nivolumab CL was similar across the tumor types examined; CL was higher for ipilimumab 1 mg/kg every 6 weeks (by 17%) and 3 mg/kg every 3 weeks (by 29%) vs. nivolumab monotherapy. Nivolumab CL over time was partially explained by time‐varying covariates. A greater decrease in nivolumab time‐varying CL was associated with increased albumin and body weight and a responder status. Our findings support the observed association between nivolumab CL and disease severity.
Pneumatically driven surgical forceps displaying a magnified grasping torque
Authors: Iwai Takuya , Kanno Takahiro , Miyazaki Tetsuro , Haraguchi Daisuke , Kawashima Kenji
Published: November 2019

Background: Sensing the grasping force and displaying the force for the operator are important for safe operation in robot‐assisted surgery. Although robotic forceps that senses the force by force sensors or driving torque of electric motors is proposed, the force sensors and the motors have some problems such as increase in weight and difficulty of the sterilization.

Method: We developed a pneumatically driven robotic forceps that estimates the grasping torque and display the magnified torque for the operator. The robotic forceps has a master device and a slave robot, and they are integrated. In the slave side, the grasping torque is estimated by the pressure change in the pneumatic cylinder. A pneumatic bellows display the torque through a linkage.

Results: We confirmed that the slave robot follows the motion of the master, and the grasping torque is estimated in the accuracy of 7 mNm and is magnified and displayed for the operator.

Conclusions: The pneumatically driven robotic forceps has the capability in the estimation of the grasping torque and display of the torque. Regarding future work, the usability and fatigues of the surgeons must be evaluated.
Disturbance attenuation with fast global finite‐time convergence for generalized high‐order uncertain nonlinear systems
Authors: Sun Zong‐Yao , Wang Min , Chen Chih‐Chiang , Meng Qinghua
Published: November 2019

This paper focuses on the problem of disturbance attenuation with fast global finite‐time convergence (FTC) for a class of generalized high‐order uncertain nonlinear systems. Combining the fast finite‐time stabilization technique with a delicate manipulation of sign functions, a new control approach is proposed to attenuate the serious uncertainties substantially, including time‐varying control coefficients, nonlinear parameters, and external disturbances, while achieving the performance evaluated in terms of L2‐L2p gain. A notable feature of the control strategy is the fast FTC, which greatly shortens the convergent time when the initial state is far away from the origin. A numerical example is provided to demonstrate the effectiveness of the proposed method.
Analysis of pulse width modulation controlled systems based on a piecewise affine description
Authors: Massioni Paolo , Bako Laurent , Scorletti Gérard , Trofino Alexandre
Published: November 2019

The problem of assuring the asymptotic stability of a pulse width modulation (PMW) control scheme is a classical topic in control engineering, where a continuous‐time control signal is approximated by a piecewise constant signal. This paper proposes a general framework that either shows the local asymptotic stability of the closed‐loop PWM system or proves the convergence of the state to an invariant set, which is the case in the presence of limit cycles. The proposed method is based on a piecewise affine representation of the closed‐loop system in discrete time, and it uses semidefinite programming both to find a Lyapunov‐like function and to determine an estimate of the region of attraction. This is an important feature since the desired continuous‐time control action at some instants may be larger than the magnitude of the PWM signals, leading to saturation of the applied control action, a well‐known source of performance degradation and even instability. Two academic examples of applications are shown, in the domain of spacecraft positioning control and electric direct current (DC) motor servoing.
Environmental factors associated with the occurrence of the Ponto–Caspian gobies in a lowland river belonging to the central European invasion corridor
Authors: Płąchocki Dariusz , Kobak Jarosław , Poznańska‐Kakareko Małgorzata , Kakareko Tomasz
Published: November 2019

Ponto–Caspian goby fish belong to the most successful invaders in freshwater ecosystems of Europe and North America. So far, three alien goby species have been present in the Polish section of the Dnieper–Rhine River corridor: the monkey goby Neogobius fluviatilis, the racer goby Babka gymnotrachelus, and the western tubenose goby Proterorhinus semilunaris. Their assemblages in this region are unique because, in contrast to their native region or the Danube–Rhine corridor, they are unaffected by other gobiid species. We conducted electrofishing and habitat quality surveys to gather information on key environmental factors associated with the distribution of these fish in the lower river Vistula, which constitutes a vast middle part of the corridor used by the Ponto–Caspian species to migrate westward in Europe. We showed that the sandy bottom was beneficial for the monkey goby allowing the species to attain the highest abundance among the gobies in the river. Habitat complexity generated by artificial bank structures, as well as dense macrophyte coverage in the main channel, favoured mostly the expansion of the racer goby. Off‐channel areas with vegetation and a muddy bottom (old river beds and pools) were the most suitable habitats for the western tubenose goby. We did not find any negative spatial relationships among gobies of various species and sizes except the avoidance of the monkey goby by small western tubenose goby. Thus, our study demonstrates substantial habitat partitioning, suggesting a low level of interspecific competition among the three species in a lowland river.
Electrochemical Reduction of N2 to NH3 Using a Co‐Atom Stabilized on Defective N‐Doped Graphene: A Computational Study
Authors: Saeidi Nasibeh , Esrafili Mehdi D. , Sardroodi Jaber Jahanbin
Published: November 2019

The catalytic reduction of N2 to NH3 under mild condition remains as a challenging and important chemical process. By performing first‐principle density functional theory calculations, the fixation and catalytic reduction of N2 are investigated over a single Co atom supported defective N‐doped graphene (Co/N3‐Gr) for the first time. All the distal, alternating and enzymatic mechanisms are investigated for the N2 activation and its conversion to ammonia. Our findings reveal that Co/N3‐Gr exhibits high catalytic performance for the low‐temperature electrochemical reduction of N2 through the enzymatic mechanism. According to our results, the hydrogen evaluation reaction cannot proceed in parallel with the N2 reduction, due to its relatively large over potential (η).
Magnetization Dynamics of an Individual Single‐Crystalline Fe‐Filled Carbon Nanotube
Authors: Lenz Kilian , Narkowicz Ryszard , Wagner Kai , Reiche Christopher F. , Körner Julia , Schneider Tobias , Kákay Attila , Schultheiss Helmut , Weissker Uhland , Wolf Daniel , Suter Dieter , Büchner Bernd , Fassbender Jürgen , Mühl Thomas , Lindner Jürgen
Published: November 2019

The magnetization dynamics of individual Fe‐filled multiwall carbon‐nanotubes (FeCNT), grown by chemical vapor deposition, are investigated by microresonator ferromagnetic resonance (FMR) and Brillouin light scattering (BLS) microscopy and corroborated by micromagnetic simulations. Currently, only static magnetometry measurements are available. They suggest that the FeCNTs consist of a single‐crystalline Fe nanowire throughout the length. The number and structure of the FMR lines and the abrupt decay of the spin‐wave transport seen in BLS indicate, however, that the Fe filling is not a single straight piece along the length. Therefore, a stepwise cutting procedure is applied in order to investigate the evolution of the ferromagnetic resonance lines as a function of the nanowire length. The results show that the FeCNT is indeed not homogeneous along the full length but is built from 300 to 400 nm long single‐crystalline segments. These segments consist of magnetically high quality Fe nanowires with almost the bulk values of Fe and with a similar small damping in relation to thin films, promoting FeCNTs as appealing candidates for spin‐wave transport in magnonic applications.
Strain Anisotropy and Magnetic Domains in Embedded Nanomagnets
Authors: Nord Magnus , Semisalova Anna , Kákay Attila , Hlawacek Gregor , MacLaren Ian , Liersch Vico , Volkov Oleksii M. , Makarov Denys , Paterson Gary W. , Potzger Kay , Lindner Jürgen , Fassbender Jürgen , McGrouther Damien , Bali Rantej
Published: November 2019

Nanoscale modifications of strain and magnetic anisotropy can open pathways to engineering magnetic domains for device applications. A periodic magnetic domain structure can be stabilized in sub‐200 nm wide linear as well as curved magnets, embedded within a flat non‐ferromagnetic thin film. The nanomagnets are produced within a non‐ferromagnetic B2‐ordered Fe60Al40 thin film, where local irradiation by a focused ion beam causes the formation of disordered and strongly ferromagnetic regions of A2 Fe60Al40. An anisotropic lattice relaxation is observed, such that the in‐plane lattice parameter is larger when measured parallel to the magnet short‐axis as compared to its length. This in‐plane structural anisotropy manifests a magnetic anisotropy contribution, generating an easy‐axis parallel to the short axis. The competing effect of the strain and shape anisotropies stabilizes a periodic domain pattern in linear as well as spiral nanomagnets, providing a versatile and geometrically controllable path to engineering the strain and thereby the magnetic anisotropy at the nanoscale.
New Barium Vanadate BaxV2O5 (x ≈ 0.16) for Fast Lithium Intercalation: Lower Symmetry for Higher Flexibility and Electrochemical Durability
Authors: Zhang Jiliang , Li Hangkong , Liao Chang‐Zhong , Lau Vincent Wing‐hei , Wong Kam Wa , Chang Chung‐Kai , Sheu Hwo‐Shuenn , Shih Kaimin , Kang Yong‐Mook
Published: November 2019

Na0.33V2O5‐type metal vanadates generally show better cycling stability than α‐V2O5 as a cathode in Li‐ion batteries, because they contain enough crystallographic voids that allow for lithium intercalation without significant structural deformation, but metal leaching upon cycling deteriorates their capacity retention. Here a new barium vanadate Ba0.16(1)V2O5 is reported that does not undergo Ba leaching during cycling and shows a great promise for fast Li intercalation. Sr0.15(1)V2O5 is isostructural to Na0.33V2O5 (space group C2/m), while Ba0.16(1)V2O5 adopts a new structure (space group P21/c), a derivative of Na0.33V2O5. The framework of Ba0.16(1)V2O5 consists of edge‐shared VO6 octahedral layers and the VO5 pyramidal bridge, generating unidirectional tunnels. Unlike the in‐plane arrangement of atoms in Sr0.15(1)V2O5, the nonplanar arrangement in Ba0.16(1)V2O5 makes the host framework more flexible and creates larger voids for Ba. Compared with the combination of displacement and intercalation mechanisms in the Sr0.15(1)V2O5 cathode, Li intercalation looks dominant in the Ba0.16(1)V2O5 cathode due to its increased flexibility. Hence, Ba0.16(1)V2O5 exhibits improved cycling stability compared to Sr0.15(1)V2O5, suggesting that lower symmetry leads to higher cyclic stability in the V2O5‐related compounds. This study illustrates how guest cations can tune the structural symmetry to modulate the reaction mechanism of electrode materials toward superior performances.
Single‐Atom Ru Doping Induced Phase Transition of MoS2 and S Vacancy for Hydrogen Evolution Reaction
Authors: Zhang Junmeng , Xu Xiaopei , Yang Liu , Cheng Daojian , Cao Dapeng
Published: November 2019

Using electrochemical water splitting to produce hydrogen is still a grand challenge due to the lack of economical and efficient Pt‐free catalysts. Herein, a single‐atom Ru supported on MoS2 (SA‐Ru‐MoS2) electrocatalyst for the hydrogen evolution reaction (HER) is reported. Results indicate that single‐atom Ru doping induces phase transition of MoS2 and generation of S vacancies, which significantly improve the performance of inert 2D MoS2 for HER. In particular, the SA‐Ru‐MoS2 electrocatalyst exhibits a low overpotential of 76 mV at 10 mA cm−2 in alkaline media, which is superior to most electrocatalysts previously reported in the literature. Combining experimental results with density functional theory (DFT) calculations, it is further revealed that the origin of high HER activity is mainly attributed to the synergy effects of single‐atom Ru doping and S vacancies and phase transition of local structure of MoS2, which efficiently tailors the electronic structure of SA‐Ru‐MoS2 and extremely reduces the energy barrier of the Volmer step and the adsorption/desorption of H* intermediate step. In short, this work provides a single‐atom doping strategy to transfer the inert MoS2 into the highly efficient electrocatalysts.
Cyclic shear resistance for seismic design, based on monotonic shear models in fib Model Code 2010 and in the 2018 draft of Eurocode 2
Authors: Biskinis Dionysis , Fardis Michael N.
Published: November 2019

Shear resistance decays during cycling of inelastic deformations, causing flexural plastic hinges to fail in cyclic shear before reaching their ultimate flexural deformation. The monotonic shear model in MC2010 does not work for shear failure after flexural yielding. Accurate, unbiased, lack‐of‐fit‐free prediction of cyclic shear resistance, before or after flexural yielding, is possible, if: (a) inelasticity is considered in the calculation of longitudinal strains at section mid‐depth, through the “equal displacement rule” of Earthquake Engineering; (b) axial forces are taken to contribute to shear resistance with the transverse component of the diagonal strut between member ends; (c) the Eurocode 2 shear model for loads near supports is used for squat members; and (d) minor changes are made to the minimum compression field angle and the concrete strength reduction along it in MC2010, Levels II or III of approximation.
Coupled‐two‐beam discrete model for dynamic analysis of tall buildings with tuned mass dampers including soil–structure interaction
Authors: Huergo Iván F. , Hernández Hugo
Published: November 2019

An equivalent coupled‐two‐beam discrete model is developed for time‐domain dynamic analysis of high‐rise buildings with flexible base and carrying any number of tuned mass dampers (TMDs). The equivalent model consists of a flexural cantilever beam and a shear cantilever beam connected in parallel by a finite number of axially rigid members that allows the consideration of intermediate modes of lateral deformation. The equivalent model is applied to a shear wall–frame building located in the Valley of Mexico, where the effects of soil–structure interaction (SSI) are important. The effects of SSI and TMDs on the dynamic properties of the shear wall–frame building are shown considering four types of soil (hard rock, dense soil, stiff soil, and soft soil) and two passive damping systems: a single TMD on its top (1‐TMD) and five uniformly distributed TMDs (5‐TMD). The results showed a great effectiveness of the TMDs to reduce the lateral seismic response and along‐wind response of the shear wall–frame building for all types of soils. Generally speaking, the dynamic response increases as the flexibility of the foundation increases.
Restorying a “Newbie” Teacher’s 3D Virtual Teaching Trajectory, Resilience, and Professional Development Through Action Research: A Narrative Case Study
Authors: Chen Julian ChengChiang
Published: November 2019

Unique affordances of 3D multi‐user virtual environments (e.g., immersive simulation, avatar tele/copresence) have attracted language teachers and researchers to explore the effects of Second Life (SL) on learners’ language outcomes and perceptions. Research on such a synergy of language education and virtual learning has suggested learners’ heightened motivation, improved communication skills, boosted confidence, and developed avatar identity. Nevertheless, the target population in prior research was predominately language learners; teachers’ professional development and beliefs in 3D virtual teaching are relatively under‐researched. Motivated by action research, this case study explores how an ESL teacher switched her role from an experienced classroom‐based teacher to an SL “newbie” teacher, thus reconstructing her teacher identity and fostering professional growth. Coinciding with narrative inquiry, her verbatim account was documented in her critical reflections in blogging, shadowed and interviewed by the researcher as her mentor. Her story epitomises an online teacher’s resilience in striving to equip herself with a new skill set and new understandings of online teaching vis‐à‐vis challenges encountered, strategies employed, and lessons learned through critical reflections in dialogue blogging. These aspects open a new avenue for research and pedagogy in virtual teacher training and professional development through action research in the 3D virtual environment.
Analysis of 270 fetuses with non‐visualization of cavum septi pellucidi and vergae on in‐utero magnetic resonance imaging
Authors: Griffiths P. D. , Jarvis D.
Published: November 2019

Objective

To analyze a large retrospective cohort of fetuses in which the cavum septi pellucidi and vergae (CSPV) was not present or was not in its expected position on in‐utero magnetic resonance imaging (iuMRI), in order to describe the possible causes of that finding and provide a diagnostic approach to assess such cases in clinical practice using iuMRI.

Methods

This was a retrospective study of fetuses that underwent iuMRI at a single institution, over an 18‐year period (2000–2017 inclusive), in which the CSPV was not visualized or was abnormal. All iuMRI studies were reviewed and classified as CSPV being not present, disrupted (visualization of remnants of an otherwise normally placed CSPV) or malpositioned (CSPV was present, but not in its expected position). We describe the neuropathology present in each of the groups.

Results

Of the 270 fetuses that met the inclusion criteria, the CSPV was described as malpositioned in 150 (56%), disrupted in 71 (26%) and not present in 49 (18%). Malpositioned CSPV was present only in cases with agenesis of the corpus callosum and three specific patterns of malpositioning are described, depending on the location of the leaflets of the CSPV and fornix. Disrupted CSPV was present in fetuses with hydrocephalus or pathologies causing extensive brain parenchymal injury. Not present CSPV was found in cases with holoprosencephaly or when absence of the CSPV appeared to be an isolated finding.

Conclusion

We have described a large cohort of fetuses with non‐visualization of a normal CSPV on iuMRI and present a categorical classification system based on the CSPV being not present, disrupted or malpositioned. This approach should help in the diagnosis of the underlying cause of a CSPV abnormality. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
Foot and mouth disease outbreak investigation and estimation of its economic impact in selected districts in northwest Ethiopia
Authors: Tadesse Belege , Tesfahun Amanuel , Molla Wassie , Demisse Eyasu , Jemberu Wudu T.
Published: November 2019

Foot and mouth disease (FMD), a highly contagious and economically important disease of cloven‐hoofed animals, is endemic in Ethiopia. Foot and mouth disease outbreak investigation and follow‐up studies were undertaken to identify the causative serotype, determine the morbidity and mortality, and estimate the economic impact of the outbreaks in selected districts of Northwest Ethiopia. The serotype of FMD virus involved in the outbreaks was identified by antigen detection ELISA from clinical samples. Morbidity, mortality and economic impact of the outbreaks were assessed based on data collected from 738 smallholder farmers in a mixed crop‐livestock (MCL) production system and from five dairy farms in the commercial dairy production system. The outbreaks were confirmed to be due to FMD virus serotype O. The animal level morbidity in clinically affected cattle herds was 68.1% for MCL production system and 54.5% for commercial dairy farms. The mortality in cattle in the MCL system was 0.4% and no mortality was recorded in the commercial dairy farms. The animal level morbidity in sheep and goats in the infected flocks was 35.7% but no mortality was seen in these species. The herd/flock level morbidity of FMD in outbreak affected kebeles of MCL system was 57.2% for cattle and 8% for sheep and goats. The economic losses due to milk loss, draught power loss, mortality and treatment cost were on average USD 34 (interquartile range: 9.4–44.4) per affected herd in the MCL system and this was statistically significantly lower than the USD 459.1 (interquartile range: 400.0–486.2) per affected farm in the commercial dairy farms (p < .05). These economic losses have significant impact in the livelihood and income of affected farmers in both production systems. Future work should focus on the implementation of control measures that mitigate the economic impact of the disease.
Contrasting molecular diversity and demography patterns in two intertidal amphipod crustaceans reflect Atlantification of High Arctic
Authors: Grabowski Michał , Jabłońska Aleksandra , Weydmann-Zwolicka Agata , Gantsevich Mikhail , Strelkov Petr , Skazina Maria , Węsławski Jan Marcin
Published: November 2019

The distribution of two common intertidal amphipod speciesGammarus oceanicusandGammarus setosuswas studied along the coast of Svalbard Archipelago. Genetic analysis showed geographical homogeneity ofG. oceanicuswith only one molecular operational taxonomic unit (MOTU) and much higher diversification ofG. setosus(5 MOTUs) in the studied area. Only two MOTUs ofG. setosusare widespread along the whole studied Svalbard coastline, whereas the remaining three MOTUs are present mainly along the northern and eastern parts of archipelago’s largest island, Spitsbergen. Distribution analysis indicates that the demographic and spatial expansion ofG. oceanicusin the northern Atlantic has started already during the Last Glacial Maximum (LGM, ca. 18 ka), whileG. setosusseems to be a long-persistent inhabitant of the Arctic, possibly even through the LGM, with slower distribution dynamics. Combining the results of our molecular study with previous field observations and the knowledge upon the direction of ocean currents around the Svalbard Archipelago, it can be assumed thatG. oceanicusis a typical boreal Atlantic species that is still continuing its postglacial expansion northwards. In recent decades it colonized High Arctic due to the climate warming and has partly displacedG. setosus, that used to be the only common gammarid of the Svalbard intertidal zone.
OH defect contents in quartz in a granitic system at 1–5 kbar
Authors: Potrafke Alexander , Stalder Roland , Schmidt Burkhard C. , Ludwig Thomas
Published: November 2019

Quartz is able to incorporate trace elements (e.g., H, Li, Al, B) depending on the formation conditions (P, T, and chemical system). Consequently, quartz can be used as a tracer for petrogenetic information of silicic plutonic bodies. In this experimental study, we provide the first data set on the OH defect incorporation in quartz from granites over a pressure/temperature range realistic for the emplacement of granitic melts in the upper crust. Piston cylinder and internally heated pressure vessel synthesis experiments were performed in a water-saturated granitic system at 1–5 kbar and 700–950 °C. Crystals from successful runs were analysed by secondary ion mass spectrometry (SIMS) and Fourier transform infrared (FTIR) spectroscopy, and their homogeneity was verified by FTIR imaging. IR absorption bands can be assigned to specific OH defects and analysed qualitatively and quantitatively and reveal that (1) the AlOH band triplet at 3310, 3378 and 3430 cm−1 is the dominating absorption feature in all spectra, (2) no simple trend of total OH defect incorporation with pressure can be observed, (3) the LiOH defect band at 3470–3480 cm−1 increases strongly in a narrow pressure interval from 4 kbar (220 µg/g H2O) to 4.5 kbar (500 µg/g H2O), and declines equally strong towards 5 kbar (180 µg/g H2O). Proton incorporation is charge balanced according to the equation H+ + A+ + P5+ = M3+ + B3+, with A+ = alkali ions and M3+ = trivalent metal ions.
Applications of off-gas mass spectrometry in fed-batch mammalian cell culture
Authors: Goh Hai-Yuan , Sulu Michael , Alosert Haneen , Lewis Graham L. , Josland Graham D. , Merriman Daniel E.
Published: November 2019

Off-gas analysis using a magnetic sector mass spectrometer was performed in mammalian cell cultures in the fed-batch mode at the 5 L bench and 50 L pilot scales. Factors affecting the MS gas traces were identified during the duration of the fed-batch cultures. Correlation between viable cell concentration (VCC) and oxygen concentration of the inlet gas into the bioreactor (O2-in) resulted in R2 ≈ 0.9; O2-in could be used as a proxy for VCC. Oxygen mass transfer (kLa) was also quantified throughout the culture period with antifoam addition at different time points which is shown to lower the kLa. Real-time specific oxygen consumption rate (qO2) of 2–20 pmol/cell/day throughout the bioreactor runs were within the range of values reported in literature for mammalian cell cultures. We also report, to our knowledge, the first instance of a distinct correlation between respiration quotient (RQ) and the metabolic state of the cell culture with regard to lactate production phase (average RQ > 1) and consumption phase (average RQ < 1).
Occurrence of strong and very strong heat stress in Poland and its circulation conditions
Authors: Tomczyk Arkadiusz M. , Owczarek Małgorzata
Published: November 2019

The primary objective of the paper was the determination of the atmospheric circulation favouring the occurrence of strong and very strong stress of the human organism due to heat stress in Poland. The paper was prepared based on data obtained from the Institute of Meteorology and Water Management – National Research Institute and the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR). The criterion of extreme stress of the human organism adopted in the paper covered conditions in which the Universal Thermal Climate Index (UTCI) value was higher than 32 °C. The research showed a statistically significant increase in half of the analysed stations and an increasing tendency or no changes in the remaining stations. Moreover, after 1990, conditions particularly strenuous for the organism were recorded (UTCI > 40 °C) over a major part of the territory of Poland. The occurrence of days with strong and very strong heat stress in Poland was related to the presence of high-pressure systems blocking zonal circulation. The research permitted the designation of three types in which the pressure field showed common features, but differed in the location of anticyclonic systems.
Projective Geometry of Wachspress Coordinates
Authors: Kohn Kathlén , Ranestad Kristian
Published: November 2019

We show that there is a unique hypersurface of minimal degree passing through the non-faces of a polytope which is defined by a simple hyperplane arrangement. This generalizes the construction of the adjoint curve of a polygon by Wachspress (A rational finite element basis, Academic Press, New York, 1975). The defining polynomial of our adjoint hypersurface is the adjoint polynomial introduced by Warren (Adv Comput Math 6:97–108, 1996). This is a key ingredient for the definition of Wachspress coordinates, which are barycentric coordinates on an arbitrary convex polytope. The adjoint polynomial also appears both in algebraic statistics, when studying the moments of uniform probability distributions on polytopes, and in intersection theory, when computing Segre classes of monomial schemes. We describe the Wachspress map, the rational map defined by the Wachspress coordinates, and the Wachspress variety, the image of this map. The inverse of the Wachspress map is the projection from the linear span of the image of the adjoint hypersurface. To relate adjoints of polytopes to classical adjoints of divisors in algebraic geometry, we study irreducible hypersurfaces that have the same degree and multiplicity along the non-faces of a polytope as its defining hyperplane arrangement. We list all finitely many combinatorial types of polytopes in dimensions two and three for which such irreducible hypersurfaces exist. In the case of polygons, the general such curves are elliptic. In the three-dimensional case, the general such surfaces are either K3 or elliptic.
Hydrodynamic Limit of the Symmetric Exclusion Process on a Compact Riemannian Manifold
Authors: van Ginkel Bart , Redig Frank
Published: November 2019

We consider the symmetric exclusion process on suitable random grids that approximate a compact Riemannian manifold. We prove that a class of random walks on these random grids converge to Brownian motion on the manifold. We then consider the empirical density field of the symmetric exclusion process and prove that it converges to the solution of the heat equation on the manifold.
The Influence of KCl and HCl on the High-Temperature Oxidation of a Fe-2.25Cr-1Mo Steel at 400 °C
Authors: Larsson E. , Liske J. , Persdotter A. , Jonsson T. , Svensson J. -E. , Johansson L. -G.
Published: November 2019

The influence of alkali- and chlorine-containing compounds on the corrosion of superheater alloys has been studied extensively. The current paper instead investigates the corrosive effects of KCl and HCl under conditions relevant to waterwall conditions. A low-alloy (Fe-2.25Cr-1Mo) steel was exposed to KCl(s), 500 vppm HCl(g) and (KCl + HCl) in the presence of 5%O2and 20% H2O at 400 °C. The results indicate that alloy chlorination by KCl occurs by an electrochemical process, involving cathodic formation of chemisorbed KOH on the scale surface and anodic formation of solid FeCl2at the bottom of the scale. The process is accompanied by extensive cracking and delamination of the iron oxide scale, resulting in a complex, convoluted scale morphology. Adding 500 vppm HCl to the experimental environment (KCl + HCl) initially greatly accelerated the formation of FeCl2at the scale/alloy interface. The accelerated alloy chlorination is attributed to HCl reacting with KOH at the scale surface, causing the cathodic process to be depolarized. A rapid slowing down of the rate of chlorination and corrosion in KCl + HCl environment was observed which was attributed to the electronically insulating nature of the FeCl2layer which forms at the bottom of the scale, disconnecting the anodic and cathodic regions.
University-linked programmes for sustainable entrepreneurship and regional development: how and with what impact?
Authors: Wagner Marcus , Schaltegger Stefan , Hansen Erik G. , Fichter Klaus
Published: November 2019

State universities are increasingly being transformed from institutions with traditional teaching and research responsibilities to have a third, societal role in sustainable regional and economic development. In doing so, universities support knowledge spillovers to improve sustainable entrepreneurial ecosystems that benefit economic revitalization or further development of regions. At the same time they promote stakeholder involvement in crucial governance processes at the regional level. Based on a comparative case study design building on three cases in Germany, our research analyses these interdependencies focussing on university-linked support programmes for sustainable entrepreneurship and the effects on sustainable regional development. Our findings provide a nuanced view clarifying the different roles universities have, how knowledge spillovers are created, and what outputs, outcomes, and effects are realized at the regional level and beyond. Specifically, we demonstrate that depending on the regional context, different configurations, pathways, and intervention points of universities may equally improve sustainable entrepreneurial ecosystems.
Evolution of Lattice Spacing of Gamma Double Prime Precipitates During Aging of Polycrystalline Ni-Base Superalloys: An In Situ Investigation
Authors: Zhang R. Y. , Qin H. L. , Bi Z. N. , Li J. , Paul S. , Lee T. L. , Zhang S. Y. , Zhang J. , Dong H. B.
Published: November 2019

Polycrystalline Ni-base superalloy Inconel 718 derives the strengthening mainly from Ni3Nb γ″ phase. To investigate the evolution of lattice spacing of γ″ precipitates, in situ neutron diffraction experiments were performed during aging heat treatment of two Inconel 718 bar samples at 780 °C for 8 hours. One sample was aged with a negligible applied stress (5 MPa) and the other with an applied tensile stress of 300 MPa. The diffraction data demonstrate three stages of lattice spacing evolution due to compositional and morphological changes during aging. (1) Stage I, the γ lattice spacing decreases isotropically in the first hour of aging as the composition changes. (2) Stage II, the γ lattice spacing decreases and the γ″ lattice spacing increases between 1 and 5 hours of aging, at this stage compositional change on the lattice evolution weakens with aging time and the morphological change becomes comparable. (3) Stage III, as aging proceeds, compositional change is negligible, while morphological change is dominant; the γ lattice spacing decreases in the longitudinal direction but increases in the transverse direction; in contrast, the converse occurs in γ″ lattice spacing evolution.
The Effect of Interface Morphology on the Electro-Mechanical Properties of Ti/Cu Clad Composites Produced by Explosive Welding
Authors: Paul Henryk , Skuza Wojciech , Chulist Robert , Miszczyk Magdalena , Gałka Aleksander , Prażmowski Mariusz , Pstruś Janusz
Published: November 2019

The effect of interfacial microstructure on the electro-mechanical properties of explosively welded titanium and copper plates is discussed. Mechanical testing proved that using detonation velocities ranging from 2000 to 3000 m s−1and stand-off distances from 1.5 to 9.0 mm, joints that satisfy the strength criteria for a good quality clad were produced. Scanning electron microscopy images show that all interfaces exhibit a wave character. It was noticed that as the stand-off distances and detonation velocities increase, the amplitude and period of the waves, as well as the quantity of the melt zones, increase as well. Also, as the interface waviness and volume fraction of the melt zones increase, the resistivity increases substantially. The experimental data demonstrate that the bonding between both metals is always achieved by surface melting of several tenths of a nanometer, which can be detected only by transmission electron microscopy. Most of the phases that form within the melt zones do not appear in the equilibrium phase diagram and show an amorphous/nano-grained structure. Only a very small amount of equilibrium phases such as CuTi3, Cu3Ti, Cu4Ti3was revealed employing synchrotron X-ray diffraction.
The role of vascular endothelial growth factor in the hypoxic and immunosuppressive tumor microenvironment: perspectives for therapeutic implications
Authors: Tamura Ryota , Tanaka Toshihide , Akasaki Yasuharu , Murayama Yuichi , Yoshida Kazunari , Sasaki Hikaru
Published: November 2019

The microvasculature and immune cells are major components of the tumor microenvironment (TME). Hypoxia plays a pivotal role in the TME through hypoxia-inducible factor 1-alpha (HIF-1α) which upregulates vascular endothelial growth factor (VEGF). VEGF, an angiogenesis stimulator, suppresses tumor immunity by inhibiting the maturation of dendritic cells, and induces immunosuppressive cells such as regulatory T cells, tumor-associated macrophages, and myeloid-derived suppressor cells. HIF-1α directly induces immune checkpoint molecules. VEGF/VEGF receptor (VEGFR)-targeted therapy as a cancer treatment has not only anti-angiogenic effects, but also immune-supportive effects. Anti-angiogenic therapy has the potential to change the immunological “cold tumors” into the “hot tumors”. Glioblastoma (GB) is a hypervascular tumor with high VEGF expression which leads to development of an immuno suppressive TME. Therefore, in the last decade, several combination immunotherapies with anti-angiogenic agents have been developed for numerous tumors including GBs. In particular, combination therapy with an immune checkpoint inhibitor and VEGF/VEGFR-targeted therapy has been suggested as a synergic treatment strategy that may show favorable changes in the TME. In this article, we discuss the cross talk among immunosuppressive cells exposed to VEGF in the hypoxic TME of GBs. Current efficient combination strategies using VEGF/VEGFR-targeted therapy are reviewed and proposed as novel cancer treatments.
Heterogeneous Consequences of Teenage Childbearing
Authors: Gorry Devon
Published: November 2019

This study finds heterogeneous effects of teen childbearing on education and labor market outcomes across socioeconomic status and race. Using miscarriages to put bounds on the causal effects of teen childbearing, results show that teen childbearing leads to lower educational attainment, lower income, and greater use of welfare for individuals who come from counties with better socioeconomic conditions. However, there are no significant adverse effects for individuals who come from counties with worse socioeconomic conditions. Across race, teen childbearing leads to negative consequences for white teens but no significant negative effects for black or Hispanic and Latino teens.
The End of the Road: State Liability for Acts of UN Peacekeeping Contingents After the Dutch Supreme Court’s Judgment in Mothers of Srebrenica (2019)
Authors: Ryngaert Cedric , Spijkers Otto
Published: November 2019

This article provides an analysis of the Dutch Supreme Court judgment in the Mothers of Srebrenica case, placing it in its context, and comparing it with earlier and related decisions, in particular the judgments in the cases of Nuhanović and Mustafić. The Mothers of Srebrenica is a foundation established to represent the interests of the approximately 6000 surviving relatives of the victims of the fall of Srebrenica during the conflict in the former Yugoslavia (1995). The foundation holds the Netherlands responsible for not having done enough to protect the victims of the Srebrenica genocide. This contribution addresses the attribution of the conduct of the United Nations peacekeeping contingent to the troop-contributing State (the Netherlands), followed by the wrongfulness of the peacekeepers’ conduct and the State’s attendant liability for damages suffered by the victims. It is argued that the Dutch State’s international responsibility was only engaged because of the exceptional circumstances present in Srebrenica at the time. In the ordinary course of events, the liability of troop-contributing States is unlikely to be engaged if the Supreme Court’s review standard were to be applied.
Conservative Governments and Latin America's Human Rights Landscape
Authors: Contesse Jorge
Published: November 2019

In 2009, as the American Convention on Human Rights turned forty, Left-wing governments ruled in almost all Latin American countries. The democratization wave that began in the late 1980s had produced a seemingly hegemonic turn to the Left—the so-called “Pink Tide.” A decade later, the political landscape was radically different. With only a few exceptions, Right-wing governments are in power throughout Latin America. The implications of the conservative wave have been felt in a number of areas—including human rights. This essay explores the ways in which the new conservative governments of Latin American have tried to curb the inter-American human rights system and examines the potential long-term consequences that their efforts may have on the regional system and the protection of human rights. It then suggests possible avenues for sound engagement between states and the system, observing that the Inter-American Court's expansive case law may cause more harm in the long run.
When Illiberals Embrace Human Rights
Authors: Huneeus Alexandra
Published: November 2019

A topic motivating much research since 2016 is the turn away from international law caused by a surge in non-liberal and nationalist governments across the world. In the realm of human rights law, scholars have noted how states are now more apt to repudiate, resist, or simply ignore their human rights obligations. This essay makes a different cut into this topic. It considers not how non-liberal actors reject human rights law, but rather what happens when they embrace it. International human rights law in Latin America—often understood as a means of promoting a cosmopolitan, liberal political order—is also being harnessed toward other types of political projects. This raises the question of how necessary the link is between human rights and political liberalism: is non-liberal engagement an existential threat, or can human rights law have a thinner commitment to liberal principles than does, for example, national constitutional law? As the American Convention on Human Rights (ACHR) turns fifty, this essay argues that the human rights law of the Americas is open-ended enough that it can incorporate, and has at times incorporated, non-liberal concerns and norms without losing coherence or legitimacy. Further, this may be an apt survival strategy, albeit not the only one, for the region's human rights institutions in our time.
Rear Visibility and Some Unresolved Problems for Economic Analysis (With Notes on Experience Goods)
Authors: Sunstein Cass R.
Published: November 2019

In 2014, the National Highway Traffic Safety Administration finalized its rear visibility regulation, which requires cameras in all new vehicles, with the goal of allowing drivers to see what is behind them and thus reducing backover accidents. In 2018, the Trump administration embraced the regulation. The rear visibility rule raises numerous puzzles. First, Congress’ grant of authority was essentially standardless – perhaps the most open-ended in all of federal regulatory law. Second, it is not easy to identify a market failure to justify the regulation. Third, the monetized costs of the regulation greatly exceeded the monetized benefits, and yet on welfare grounds, the regulation can plausibly be counted as a significant success. Rearview cameras produce a set of benefits that are hard to quantify, including increased ease of driving, and those benefits might have been made a part of “breakeven analysis,” accompanying standard cost-benefit analysis. In addition, rearview cameras significantly improve the experience of driving, and it is plausible to think that in deciding whether to demand them, many vehicle purchasers did not sufficiently anticipate that improvement. This is a problem of limited foresight; rearview cameras are “experience goods.” A survey conducted in 2019 strongly supports this proposition, finding that about 56 % of consumers would demand at least $300 to buy a car without a rearview camera, and that fewer than 6 % would demand $50 or less. Almost all of that 6 % consists of people who do not own a car with a rearview camera. (The per-person cost is usually under $50.) These conclusions have general implications for other domains in which regulation has the potential to improve social welfare, even if it fails standard cost-benefit analysis; the defining category involves situations in which people lack experience with a good whose provision might have highly beneficial welfare effects.
Strategic risk dominance in collective systems design
Authors: Grogan Paul T. , Valencia-Romero Ambrosio
Published: November 2019

Engineered system architectures leveraging collaboration among multiple actors across organizational boundaries are envisioned to be more flexible, robust, or efficient than independent alternatives but also carry significant downside risks from new interdependencies added between constituents. This paper transitions the concept of risk dominance from equilibrium selection in game theory to engineering design as a strategic measure of collective stability for system of systems. A proposed method characterizes system design as a bi-level problem with two or more asymmetric decision-makers. A measure of risk dominance assesses strategic dynamics with respect to the stability of joint or collaborative architectures relative to independent alternatives using a novel linearization technique to approximate linear incentives among actors. An illustrative example case for an asymmetric three-player design scenario shows how strategic risk dominance can identify and mitigate architectures with unstable risk-reward dynamics.